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https://codegolf.stackexchange.com/questions/167366/fifo-cache-anomalies/167371 | # FIFO cache anomalies
### This is the followup challenge from this one, if you're confused please check that one out first.
First, let $m(s, k)$ be the number of cache misses a sequence $s$ of resource accesses would have assuming our cache has capacity $k$ and uses a first-in-first-out (FIFO) ejection scheme when it is full.
Then given a ratio $r > 1$, return a non-empty sequence of resources accesses $s$ such that there exists $k > j$ with $m(s, k) \geq r \cdot m(s, j)$.
In plain English, construct a sequence $s$ of resource accesses so that there's two cache sizes where the bigger cache has (at least) $r$ times more cache misses when used to resolve $s$.
An example for $r = 1.1$, a valid output is the sequence $(3, 2, 1, 0, 3, 2, 4, 3, 2, 1, 0, 4)$, as it causes $9$ cache misses for a cache size of $3$, but $10$ misses for a cache size of $4$.
It doesn't matter what sequence you return, as long as it meets the requirements.
Shortest code in bytes wins.
• Background reading: Bélády's anomaly – dylnan Jun 23 '18 at 22:26
• Might just be the exhaustion, but this challenge isn't entirely clear to me; could you provide a worked example and a couple more test cases? – Shaggy Jun 23 '18 at 22:56
• @Shaggy Go check out the other challenge, and the background reading from the other comment. The crux is that a FIFO cache can get worse as it becomes bigger for some series of requests. – orlp Jun 23 '18 at 23:08
# Wolfram Language (Mathematica), 124113 101 bytes
Flatten@{s=⌈2#⌉;q=Range[r=2s+1];g=Mod[q s-s,r];{Sort@g[[#+1;;]],g[[;;#]]}&~Array~r,Table[q,s^3]}&
Try it online!
NOTE: The TIO output is not the actual list because it would be very long. The wrapper function on TIO tells you the number of page faults for two cache capacities.
For the actual list: Try it online!
Related: arXiv:1003.1336
### How?
Let's assume a situation where we have two cache capacities, 3 and 4.
Also, let's say the 3-cache has {4, 2, 5} paged, and 4-cache has {5, 4, 3, 2} paged. Then, let's try paging {1, 2, 3, 4, 5, 1, 2, 3, 4, 5}:
page 3-cache 4-cache
{4,2,5} {5,4,3,2}
1 {1,4,2} {1,5,4,3}
2 {1,4,2} {2,1,5,4}
3 {3,1,4} {3,2,1,5}
4 {3,1,4} {4,3,2,1}
5 {5,3,1} {5,4,3,2}
1 {5,3,1} {1,5,4,3}
2 {2,5,3} {2,1,5,4}
3 {2,5,3} {3,2,1,5}
4 {4,2,5} {4,3,2,1}
5 {4,2,5} {5,4,3,2}
The 3-cache had 5 page faults, while the 4-cache had 10. We also returned to our original state.
Here, if we repeat paging {1, 2, 3, 4, 5}, we would asymptotically reach the ratio of 2.
We can extend this phenomenon to higher cache capacities so that we can page {1, 2, 3, ... , 2n + 1} and end up with any ratio. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6816171407699585, "perplexity": 1693.960271207091}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987838289.72/warc/CC-MAIN-20191024012613-20191024040113-00169.warc.gz"} |
https://cdsweb.cern.ch/collection/CMS%20Conference%20Reports?ln=ka&as=1 | # CMS Conference Reports
უკანასკნელი დამატებები:
2018-03-08
14:58
Recent Heavy Flavour results from CMS / Lacaprara, Stefano (INFN, Padua) /CMS Collaboration Recent results on b-flavour physics obtained by the CMS Collaboration will be presented. The flexible and poweful CMS trigger system allows the experiment to be sensitive to b-physics phenomena of different kinds, mostly in channels with muons in the final state. [...] CMS-CR-2018-023.- Geneva : CERN, 2018 - 15 p. Fulltext: PDF; In : XXIV Cracow Epiphany Conference on Advances in Heavy Flavour Physics, Cracow, Poland, 9 - 12 Jan 2018
2018-03-08
14:58
Upgrades of the CMS muon system in preparation of HL-LHC / Teyssier, Daniel Francois (Aachen, Tech. Hochsch.) /CMS Collaboration The present CMS muon system operates three different detector types in the barrel drift tubes (DT) and resistive plate chambers (RPC), along with cathode strip chambers (CSC) and another set of RPCs in the forward regions. In order to cope with increasingly challenging conditions various upgrades are planned to the trigger and muon systems. [...] CMS-CR-2017-445.- Geneva : CERN, 2017 - 5 p. Fulltext: PDF; In : 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017), Atlanta, Georgia, USA, 21 - 28 Oct 2017
2018-02-23
10:32
The CMS ECAL Upgrade for Precision Crystal Calorimetry at the HL-LHC / Petyt, David Anthony (Rutherford) /CMS Collaboration The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid Experiment (CMS) is operating at the Large Hadron Collider (LHC) in 2016 with proton-proton collisions at 13 TeV center-of-mass energy and at a bunch spacing of 25 ns. Challenging running conditions for CMS are expected after the High-Luminosity upgrade of the LHC (HL-LHC). [...] CMS-CR-2018-006.- Geneva : CERN, 2018 - 8 p. Fulltext: PDF; In : The 21st Particles & Nuclei International Conference, Beijing, China, 1 - 5 Sep 2017
2018-02-19
12:59
Systematic studies of charge-dependent azimuthal correlation in pPb and PbPb collisions at the LHC / Tu, Zhoudunming (Rice U.) /CMS Collaboration Studies of charge-dependent azimuthal correlations for same- and opposite-sign particle pairs are presented in PbPb collisions at 5.02 TeV and pPb collisions at 5.02 and 8.16 TeV, with the CMS experiment at the LHC. The azimuthal correlations are evaluated with respect to the second- and also higher-order event planes, as a function of particle pseudorapidity and transverse momentum, and event multiplicity. [...] CMS-CR-2017-373.- Geneva : CERN, 2017 - 11 p. Fulltext: PDF; In : 11th International Workshop on Critical Point and Onset of Deconfinement, Stony Brook, NY, USA, 07 - 11 Aug 2017
2018-02-19
12:59
Higgs Boson Measurements in CMS with Run II Data / Kumar, Ashok (Delhi U.) /CMS Collaboration Latest results from the CMS experiment on studies of Higgs boson production are presented. Studies involving the 125 GeV Higgs boson using various Standard Model production and decay modes have been performed using proton proton collisions from data accumulated during the LHC Run II with center-of-mass energy of 13 TeV. [...] CMS-CR-2017-444.- Geneva : CERN, 2017 - 6 p. Fulltext: PDF; In : Light Cone 2017 : Frontiers in Light Front Hadron Physics : Theory and Experiment., Mumbai, Maharashtra, India, 18 - 22 Sep 2017
2018-02-19
10:11
Operation and Performance of the CMS Outer Tracker / Butz, Erik Manuel (KIT, Karlsruhe, EKP) /CMS Collaboration The CMS Silicon Strip Tracker with its more than 15000 silicon modules and 200\,m$^2$ of active silicon area has been running together with the other subsystems of CMS for several years. We present the performance of the detector in the LHC Run 2 data taking. [...] CMS-CR-2017-428.- Geneva : CERN, 2017 - 11 p. Fulltext: PDF; In : The 26th International Workshop on Vertex Detectors , Las Caldas, Spain, 10 - 15 Sep 2017
2018-02-15
16:50
Beam-dynamic effects at the CMS BRIL van der Meer scans / Babaev, Anton (TOMSK-POLYTEC) /CMS Collaboration The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is responsible for the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS experiment. The project is engaged in operating and developing new detectors (luminometers), adequate for the experimental conditions associated with high values of instantaneous luminosity delivered by the CERN LHC. [...] CMS-CR-2017-415.- Geneva : CERN, 2017 - 8 p. Fulltext: PDF; In : 12th Symposium on Radiation from Relativistic Electrons in Periodic Structures, Hamburg, Germany, 18 - 22 Sep 2017
2018-02-15
16:34
Photon-photon measurements in CMS / Chudasama, Ruchi (Bhabha Atomic Res. Ctr.) /CMS Collaboration We discuss the measurement of photon-photon processes using data collected by the CMS experiment in pp collisions at $\sqrt{s}$ = 7 and 8 TeV and in PbPb collisions at $\sqrt{s_{_{{\rm NN}}}}= 5.02$ TeV.. CMS-CR-2017-218.- Geneva : CERN, 2017 - 6 p. Fulltext: PDF; In : International Conference on the Structure and the Interactions of the Photon, including the 22th International Workshop on Photon-Photon Collisions, Geneva, Switzerland, 22 - 26 May 2017
2018-02-15
16:33
CMS Pixel detector development for the HL-LHC / Schwandt, Joern (Hamburg U.) /CMS Collaboration An upgrade program is underway which will bring the luminosity of the LHC up to about 7.5x10$^{34}$ cm$^{-2}$s$^{-1}$ in 2027, with the goal of an integrated luminosity of 3000~fb$^{-1}$ by the end of 2037. This High Luminosity scenario, HL-LHC, will present new challenges of higher data rates and increased radiation hardness for the pixel detector (a non-ionizing fluence of 2x10$^{16}$~n$_{eq}$/cm$^2$ and an ionizing dose of 10~MGy, is expected on the inner pixel layer for 3000~fb$^{-1}$ integrated luminosity). [...] CMS-CR-2018-018.- Geneva : CERN, 2018 - 7 p. Fulltext: PDF; In : 11th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors (HSTD11) in conjunction with 2nd Workshop on SOI Pixel Detectors (SOIPIX2017) at OIST, Okinawa, Japan, Okinawa, Japan, 10 - 15 Dec 2017
2018-02-15
16:32
Silicon-Based Detectors at the HL-LHC / Hartmann, Frank (KIT, Karlsruhe, EKP) /ALICE,ATLAS,CMS and LHCB Collaborations This document discusses the silicon-based detectors planned for the High Luminosity LHC. The special aspects to cope with the new environment and its challenges, e.g. [...] CMS-CR-2018-015.- Geneva : CERN, 2018 - 12 p. Fulltext: PDF; In : 11th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors (HSTD11) in conjunction with 2nd Workshop on SOI Pixel Detectors (SOIPIX2017) at OIST, Okinawa, Japan, Okinawa, Japan, 10 - 15 Dec 2017 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9518423676490784, "perplexity": 8773.843972721372}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647244.44/warc/CC-MAIN-20180319234034-20180320014034-00749.warc.gz"} |
https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B5/527/2016/ | The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B5, 527–531, 2016
https://doi.org/10.5194/isprs-archives-XLI-B5-527-2016
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B5, 527–531, 2016
https://doi.org/10.5194/isprs-archives-XLI-B5-527-2016
15 Jun 2016
15 Jun 2016
# EXPERIMENTAL ASSESSMENT OF THE QUANERGY M8 LIDAR SENSOR
M.-A. Mitteta, H. Nouira, X. Roynard, F. Goulette, and J.-E. Deschaud M.-A. Mitteta et al.
• MINES ParisTech, PSL Research University, Centre for robotics, 60 Bd St Michel 75006 Paris, France
Keywords: Quanergy M8 / LIDAR / range imaging / calibration / point cloud / assessment
Abstract. In this paper, some experiments with the Quanergy M8 scanning LIDAR system are related. The distance measurement obtained with the Quanergy M8 can be influenced by different factors. Moreover, measurement errors can originate from different sources. The environment in which the measurements are performed has an influence (temperature, light, humidity, etc.). Errors can also arise from the system itself. Then, it is necessary to determine the influence of these parameters on the quality of the distance measurements. For this purpose different studies are presented and analyzed. First, we studied the temporal stability of the sensor by analyzing observations during time. Secondly, the assessment of the distance measurement quality has been conducted. The aim of this step is to detect systematic errors in measurements regarding the range. Differents series of measurements have been conducted : at different range and in diffrent conditions (indoor and outdoor). Finally, we studied the consistency between the differents beam of the LIDAR. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8104625940322876, "perplexity": 4637.177686849494}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656104141372.60/warc/CC-MAIN-20220702131941-20220702161941-00757.warc.gz"} |
http://www.integreat.ca/NOTES/CALG/04.02.html | Algebra I / Elem. Algebra
Introduction to Algebra Linear Equations and Inequalities Functions and Graphs I Lines and thier Graphs Linear Systems
Algebra II / E&I Algebra
Exponents & Polynomials Intermediate Algebra starts here!
Factoring Rational Expressions Rational Equations and Applications
Algebra III / Inter. Algebra
Radical Expressions Nonlinear Equations and Applications Functions and Graphs II Exponential and Logarithmic Functions
College Algebra
Equations and Inequalitites Functions and Graphs Polynomial and Rational Functions Exponential and Logarithmic Functions Systems and Matrices Geometry Basics Conic Sections Sequences and Series
Trigonometry
The Six Trigonometric Functions Right Triangle Trigonometry Circular Functions Graphs of Trigonometric Functions Trigonometric Identities Trigonometric Equations Oblique Triangles and the Laws Vectors Complex, Parametric, and Polar Forms
Calculus I
Limits and Continuity Derivatives Analysis of Curves Antiderivatives
Calculus II
Transcendental Functions
Geometry Physics Integration Techniques Calculus of Infinity Parametric, Polar, and Conic Curves
Calculus III
Calculus IV
15.Functions of Several Variables
16.Multiple Integration
17.Vector Analysis
Course: College Algebra
Topic: Exponential and Logarithmic Functions
Subtopic: Logarithmic Functions and Graphs
Overview
Since much of the material in this lesson is review from an intermediate algebra course, our focus here will be to expand on the basic topics, bump-up the level of difficulty, and get logarithmic functions down really well. As you work through the material, try to do what you can algebraically as well as take advantage of technology where appropriate.
Objectives
By the end of this topic you should know and be prepared to be tested on:
• 4.2.1 Understand the basic logarithmic function f(x)=logb(x) and its graph including being able to produce its graph both manually and that it is the inverse of the function g(x)=bx
• 4.2.2 Evaluate f(x)=logb(x) for given values of b and x both manually and electronically
• 4.2.3 Convert from logarithmic form to exponential form and from exponential form to logarithmic form
• 4.2.4 Know the features of the graph of f(x)=logb(x) including basic shape, domain, range, intercepts, and asymptotes
• 4.2.5 Understand the effects of a, c, and d in y=a·logb(x-c)+d on the graph of f(x)=logb(x) including reflections, stretches and shrinks, vertical and horizontal shifts (translations)
• 4.2.6 Understand the common logarithm function log(x) and the natural logarithm function ln(x) including some history of their origins and applications in science
• 4.2.7 Understand the common and natural logarithmic functions including that they are inverses of the functions 10x and ex, respectively
• 4.2.8 Convert common and natural logarithms from from logarithmic form to exponential form and from exponential form to logarithmic form
• 4.2.9 Produce the graphs of the common and natural logarithmic functions both manually and electronically
• 4.2.10 Evaluate the common and natural logarithmic functions for given values of x both manually and electronically
Terminology
Define: logarithmic function, common logarithm, natural logarithm
Supplemental Resources (optional)
If you need supplemental tutorial videos with examples relevant to this section go to James Sousa's MathIsPower4U and search for topics below. Some will be review material from Intermediate Algebra and some will be the more challenging level of this course.
"Using the Definition of a Logarithm"
"Evaluating Logarithmic Expressions"
"Graphing Logarithmic Functions" | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8493717312812805, "perplexity": 2756.007189463695}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232257939.82/warc/CC-MAIN-20190525084658-20190525110658-00355.warc.gz"} |
https://blog.heroku.com/apache-kafka-010-evaluating-performance-in-distributed-systems | # Apache Kafka 0.10
At Heroku, we're always striving to provide the best operational experience with the services we offer. As we’ve recently launched Heroku Kafka, we were excited to help out with testing of the latest release of Apache Kafka, version 0.10, which landed earlier this week. While testing Kafka 0.10, we uncovered what seemed like a 33% throughput drop relative to the prior release. As others have noted, “it’s slow” is the hardest problem you’ll ever debug, and debugging this turned out to be very tricky indeed. We had to dig deep into Kafka’s configuration and operation to uncover what was going on.
## Background
We've been benchmarking Heroku Kafka for some time, as we prepared for the public launch. We started out benchmarking to help provide our users with guidance on the performance of each Heroku Kafka plan. We realized we could also give back to the Kafka community by testing new versions and sharing our findings. Our benchmark system orchestrates multiple producer and consumer dynos, allowing us to fully exercise a Kafka cluster and determine its limits across the various parameters of its use.
## Discovery
We started benchmarking the Kafka 0.10.0 release candidate shortly after it was made available. In the very first test we ran, we noted a 33% performance drop. Version 0.9 on the same cluster configuration provided 1.5 million messages per second in and out at peak, and version 0.10.0 was doing just under 1 million messages per second. This was pretty alarming. There could be some major disincentives to upgrade to this version with such a large reduction in throughput, if this condition were present for all users of Kafka.
We set out to determine the cause (or causes) of this decrease in throughput. We ran dozens of benchmark variations, testing a wide variety of hypotheses:
• Does this only impact our largest plan? Or are all plans equally impacted?
• Does this impact a single producer, or do we have to push the boundaries of the cluster to find it?
• Does this impact plaintext and TLS connections equally?
• Does this impact large and small messages equally?
• And many other variations.
We investigated many of the possible angles suggested by our hypotheses, and turned to the community for fresh ideas to narrow down the cause. We asked the Kafka mailing list for help, reporting the issue and all the things we had tried. The community immediately dove into trying to reproduce the issue and also responded with helpful questions and pointers for things we could investigate.
During our intensive conversation with the community and review of the conversations that lead up to the 0.10 release candidate, we found this fascinating thread about another performance regression in 0.10. This issue didn't appear to line up with the problem we had found, but it helped provide more insight into Kafka that helped us understand the root cause of our particular problem. We found this other issue to be very counter-intuitive: increasing the performance of a Kafka broker can actually negatively impact performance of the whole system. Kafka relies very heavily on batching, and if the broker becomes faster, the producers batch less often. Version 0.10 included several improvements to the broker's performance, and that caused odd performance impacts that have since been fixed.
To help us proceed in a more effective and deliberate manner, we started applying Brendan Gregg's USE method to a broker during benchmarks. The USE method helps structure performance investigations, and is very easy to apply, yet also very robust. Simply, it says:
1. Make a list of all the resources used by the system (network, CPU, disks, memory, etc)
2. For each resource, look at the:
1. Utilization: the average time the resource was busy servicing work
2. Saturation: the amount of extra work queued for the resource
3. Errors: the count of error events
We started going through these, one by one, and rapidly confirmed that Kafka is blazingly fast and easily capable of maxing out the performance of your hardware. Benchmarking it will quickly identify the bottlenecks in your setup.
What we soon found is that the network cards were being oversaturated during our benchmarking of version 0.10, and they were dropping packets because of the number of bytes they were asked to pass around. When we benchmarked version 0.9, the network cards were being pushed to just below their saturation point. What changed in version 0.10? Why did it lead to saturation of the networking hardware under the same conditions?
## Understanding
Kafka 0.10 brings with it a few new features. One of the biggest ones, which was added to support Kafka Streams and other time-based capabilities, is that each message now has a timestamp to record when it is created. This timestamp accounts for an additional 8 bytes per message. This was the issue. Our benchmarking setup was pushing the network cards so close to saturation that an extra 8 bytes per message was the problem. Our benchmarks run with replication factor 3, so an additional 8 bytes per message is an extra 288 megabits per second of traffic over the whole cluster:
$${288}\ \text{Mbps}\ \ \ \ =\ \ \ {8} \textstyle \frac{\text{bytes}}{\text{message}}\ \ \ \times\ \ \ {1.5}\ \text{million} \frac{\text{messages}}{\text{second}}\ \ \ \times\ \ \ {8} \frac{\text{bits}}{\text{byte}}\ \ \ \times\ \ \ {3}\ \tiny\text{(1 for producer, 2 for replication)}$$
This extra traffic is more than enough to oversaturate the network. Once the network cards are oversaturated, they start dropping packets and doing retransmits. This dramatically reduces network throughput, as we saw in our benchmarks.
To further verify our hypothesis, we reproduced this under Kafka 0.9. When we increased the message size by 8 bytes, we saw the same performance impact.
## Giving Back
Ultimately, there's not much to do here in terms of fixing this issue by making changes to Kafka’s internals. Any Kafka cluster that runs close to the limits of its networking hardware will likely see issues of this sort, no matter what version. Kafka 0.10 just made the issue more apparent in our analyses, due to the increase in baseline message size. These issues would also happen if you as a user added a small amount of overhead to each message and were driving sufficient volume through your cluster. Production use cases tend to have a lot of variance in message size (usually a lot more than 8 bytes), so we expect most production uses of Kafka to not be impacted by the overhead in 0.10. The real trick is not to saturate your network in the first place, so it pays to model out an approximation of your data relative to your configuration.
We contributed a documentation patch about the impact of the increased network traffic so that other Kafka users don't have to go through the same troubleshooting steps. For Heroku Kafka, we've been looking at a few networking improvements we can make to the underlying cluster configurations to help mitigate the impact of the additional message overhead. We've also been looking at improved monitoring and bandwidth recommendations to better understand the limits of possible configurations, and to be able to provide a graceful and stable operational experience with Heroku Kafka.
Kafka 0.10 is in beta on Heroku Kafka now. For those of you in the Heroku Kafka beta, you can provision a 0.10 cluster like so:
heroku addons:create heroku-kafka --version 0.10
We encourage you to check it out. Kafka Streams, added in version 0.10, makes many kinds of applications much easier to build. Kafka Streams works extremely well with Heroku, as it's just a (very powerful) library you embed in your application.
If you aren't on the beta, you can request access here: https://heroku.com/kafka
We would recommend that you continue to use Kafka 0.9.0.1, the default for Heroku Kafka, for production use. We are working closely with the community to further test and validate 0.10 as ready for production use. We take some time to do this, in order to iron out any bugs with new releases for our customers. The only way that happens is if people try it out with their applications (for example in a staging environment), so we welcome and encourage your use of the new version. We can’t wait to see what you build!
Browse the archives for engineering or all blogs Subscribe to the RSS feed for engineering or all blogs. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.20658840239048004, "perplexity": 1751.2650929688075}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806842.71/warc/CC-MAIN-20171123142513-20171123162513-00606.warc.gz"} |
https://www.physicsforums.com/threads/saw-this-question-online.629111/ | # Saw this question online.
• Start date
• #1
20
0
The amount of water in a tank doubles every minute. If the tank was full at the 1 hour mark, when was the tank half full?
=============================
It's not homework, I'm just trying to get the actual (reasoned) answer..
=============================
Here is the answer I argued (though, I'm not sure):
2^x = [(2^59)/2]
2^x = 2^58
x = 58
=============================
But, almost everyone argues:
If it doubles every minute, isn't it half full the minute before it's full? ie. 59
=============================
Pretty sure I'm incorrect, I just want to know for sure..
Last edited:
## Answers and Replies
• #2
296
0
The argument of everyone (not yours) is correct.
Your working is correct as well, its just that your first equation is wrong.
Last edited:
• #3
Mentallic
Homework Helper
3,798
94
V = k*2x, where x is in minutes and k is some unknown constant (the volume of the tank at the start of the timer x=0).
At x=60 the tank is full, therefore, if we denote the full volume of the tank as Vf then Vf=k*260. Now, We want to know when the tank is half full, which is Vf/2
Clearly, Vf/2 = k*260/2 = k*259
If we compare this to the original equation, x=59 minutes as you would expect.
I know this explanation is long-winded, but I hope it got the point across as to how you should have set up the equation.
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801 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.922664225101471, "perplexity": 2791.343613446811}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487630081.36/warc/CC-MAIN-20210625085140-20210625115140-00492.warc.gz"} |
https://11011110.github.io/blog/2016/10/14/kolakoski-sequence-via.html | After posting about a recursive generator for the Kolakoski sequence yesterday, I found the following alternative and non-recursive algorithm, which generates the same sequence in a linear number of bit operations with a logarithmic number of bits of storage.
Like the previous one, this can be understood as traversing an infinite tree. The tree is defined using essentially the same rules as before: two consecutive nodes on the same level of the tree have the same number of children if and only if they have the same parent. However, it extends infinitely upward rather than infinitely downward, with two children for each node on the leftmost path. Each level of the tree has the same sequence of degrees, which equals the Kolakoski sequence starting from its second position (the missing first position is why this starts at x = y = -1 rather than zero).
The algorithm traverses the bottom level of the tree in left-to-right order. As it does, the variable x maintains, in its binary representation, the numbers of children modulo 2 of the path of nodes extending infinitely upwards from the current leaf. All but finitely many (logarithmically many as a function of the position of the leaf) of these bits are zero, so (after the first step) x is a non-negative finite number with logarithmically many bits. The variable y, similarly, maintains a sequence of bits corresponding to the nodes on the same path that are 0 when the node is a left child of a degree-2 node and 1 otherwise. Again, finitely many of these bits are 1, so y is non-negative with logarithmically many bits. The bit manipulation tricks of the algorithm merely update these two variables to describe the next path in the traversal.
Update 10/16: Fast C++ implementation by Jörg Arndt | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8027874231338501, "perplexity": 289.9324125968515}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030337853.66/warc/CC-MAIN-20221006155805-20221006185805-00007.warc.gz"} |
http://blog.uml.edu/cotangents/author/levasseur-kenneth-1/2012/02/ | # Levasseur, Kenneth: February 2012 Archives
## Brown-Bag Applied Math Seminar
$\int_0^x f(t) k(x,t) \, dt$
A Brown-Bag Applied Math Seminar has been launched in the UMass Lowell Department of Mathematical Sciences. Meetings are scheduled every Friday from noon to 1 PM in Olney 218. The first meeting is scheduled for Friday, February 17, 2012.
Interested students (both undergraduate and graduate) as well as interested faculty are welcome to attend.
This is a lunch-time working Seminar, so please feel free to bring your lunch or your favorite beverage, or just bring yourself!!
The seminar is being organized by Dimitris Christodoulou, [email protected]
This page is a archive of recent entries written by Levasseur, Kenneth in February 2012.
Levasseur, Kenneth: July 2011 is the previous archive.
Levasseur, Kenneth: April 2012 is the next archive.
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https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=41&t=32539&p=104369 | ## final [ENDORSED]
(Polar molecules, Non-polar molecules, etc.)
Posts: 29
Joined: Fri Apr 06, 2018 11:01 am
### final
We're not expected to know the MO theory right? i know he mentioned it briefly in class...
Chem_Mod
Posts: 19640
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 891 times
### Re: final [ENDORSED]
Correct. No MO theory. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8431281447410583, "perplexity": 27320.973274868564}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178375439.77/warc/CC-MAIN-20210308112849-20210308142849-00442.warc.gz"} |
https://espanol.libretexts.org/Ciencias_Sociales/Educacion_de_la_Primera_Infancia/Libro%3A_Introduccion_al_plan_de_estudios_para_la_educacion_en_la_primera_infancia_(Paris_Beeve_y_Springer)/13%3A_Desarrollo_Fisico | Saltar al contenido principal
# 13: Desarrollo Físico
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Objetivos
Al finalizar el capítulo podrás:
13: Desarrollo Físico is shared under a CC BY license and was authored, remixed, and/or curated by Jennifer Paris, Kristin Beeve, & Clint Springer. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9985172152519226, "perplexity": 6566.563773341441}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662570051.62/warc/CC-MAIN-20220524075341-20220524105341-00312.warc.gz"} |
https://www.physicsforums.com/threads/solutions-of-a-diophantine-equation.389779/ | # Solutions of a diophantine equation
1. Mar 25, 2010
### zetafunction
given the diophantine polynomial equation
$$f(x)=0mod(p)$$
then is the number of solution approximately less than a given N approximately
$$\sum_{i\le N}e^{2i p\pi f(j)}$$
the idea is that the sum takes its maximum value every time p divides f(j) for some integer 'j''
2. Mar 27, 2010
### Petek
I replied yesterday (March 26), but the reply was lost with the server problems. I'll try again:
Your summation expression appears to have a typo. If n is any integer, then
$$e^{2i p\pi n} = 1$$
so the expression always sums to N. Perhaps you meant to divide by p in the exponent instead of multiplying by p. Questions of this sort are discussed in the first few sections of Number Theory by Borevich and Shafarevich.
1. You might want to test your formula with $f(x) = x^p - x$, since all natural numbers are solutions.
2. In general, your sum will be a complex number. In what sense do you want to consider a complex number to approximate the number of solutions?
Petek
Similar Discussions: Solutions of a diophantine equation | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8907600045204163, "perplexity": 583.0031079765769}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934807089.35/warc/CC-MAIN-20171124051000-20171124071000-00409.warc.gz"} |
https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=160&t=62437 | ## Final time
General non-science questions and class announcements.
Alexis Robles 2k
Posts: 100
Joined: Wed Sep 18, 2019 12:18 am
### Final time
So the online final is going to be at the same time as if it were the in-person final?
Ipsita Srinivas 1K
Posts: 50
Joined: Mon Jun 17, 2019 7:24 am
### Re: Final time
Yup
005290099
Posts: 24
Joined: Sat Aug 24, 2019 12:16 am
### Re: Final time
I do not think so but he is going to send out an email with all the information today so I think we should just wait for him to lay out the details later today.
CNourian2H
Posts: 106
Joined: Fri Aug 30, 2019 12:16 am
### Re: Final time
Ya his email says it is. Just make sure you log on at 11:15(i think that is the time)!
MTanikella_1K
Posts: 110
Joined: Sat Jul 20, 2019 12:16 am
### Re: Final time
Yes the final will be from 11:15AM to 2:45 PM.
Vivianvelazquez_1J
Posts: 109
Joined: Thu Jul 11, 2019 12:17 am
Been upvoted: 1 time
### Re: Final time
Yes, except he gave us an extra 30 minutes to sign in, it’s from 11:15am to 2:45pm. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8397091031074524, "perplexity": 7565.965489932593}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610704795033.65/warc/CC-MAIN-20210126011645-20210126041645-00104.warc.gz"} |
http://summer.mruni.eu/crhb88e/ley4xnq.php?9933db=order-of-a-matrix-2-5-7-is | Find the vertex of the parabola. [1 2 3] [2 4 6] [0 0 0] How to calculate the rank of a matrix: In this tutorial, let us find how to calculate the rank of the matrix. Solved Examples For You. For example, A = [1 2 4 5] is row matrix of order 1 x 4. (i) State the order of matrix M(ii) Find the matrix M - Mathematics. Order of Operations Factors & Primes Fractions Long Arithmetic Decimals Exponents & Radicals Ratios & Proportions Percent Modulo Mean, Median & Mode Scientific Notation Arithmetics Algebra Equations Inequalities System of Equations System of Inequalities Basic Operations Algebraic Properties Partial Fractions Polynomials Rational Expressions Sequences Power Sums Induction Logical Sets A. Read More. Factoring Trinomials Box Method. asked Feb 26, 2019 in Class X Maths by priya12 ( -12,631 points) matrices Thus, A = [a ij] mxn is a column matrix if n = 1. This website uses cookies to ensure you get the best experience. The order of the above matrix is (2×2), since the number of rows (m) = 2 and the number of columns (n) = 2. MEDIUM. A system of two linear equations in two unknown x and y are as follows: Let , , . Let A be any square matrix of order n x n and I be a unit matrix of same order. Hence, the order is m × 1. Since matrix multiplication is not commutative, the inverse matrix should be at the left on each side of the matrix equation. For example: This matrix is a 3x4 (pronounced "three by four") matrix because it has 3 rows and 4 columns. Advertisement. Column Matrix. On the right side, fill in elements of the identity matrix. X[(1,2,3),(4,5,6)]= [(-7,-8,-9),(2,4,6)] The matrix given on the R.H.S. of the equation is a 2 × 3 matrix and the one given on the L.H.S. share | cite | improve this question | follow | edited Nov 17 '19 at 15:51. idon'tknow. We can clearly see, a matrix of the order m × n has mn elements. An example of a column matrix is: A = [− 1 2 − 4 5] \begin{bmatrix} -1\\ 2\\ -4\\ 5 … If n = p, then the order of the matrix 7X – 5Z is (A)p × 2 (B) 2 × n (C) n × 3 (D) p × n X =[ 8(1&0@2&3)]_(2 × 2) 7X =[ 8(7&0@14&21)]_(2 × 2) 7X – 5Z =[ 8(7&0@14&21)]_(2 × 2)– [ 8(0&10@15&5)]_(2 × 2)=[ 8(7&−10@−1&16)]_(2 × 2) ∴ Order of X = Order of 7X & Order of Z = Order … OK, how do we calculate the inverse? Join Now. There are 5 inequivalent matrices of order 16, 3 of order 20, 60 of order 24, and 487 of order 28. In this example, the order of the matrix is 3 × 6 (read '3 by 6'). Dec 03, 20 04:58 AM . Space Complexity: O(1). Exercise 9 (B) | Q 11 | Page 122. AX = B and X = . In the matrix, every equation in the system becomes a row and each variable in the system becomes a column and the variables are dropped and the coefficients are placed into a matrix. Matrix entry (or element) Maths MCQs for Class 12 Chapter Wise with Answers PDF Download was Prepared Based on Latest Exam Pattern. In the above example, we have A as a matrix of order 3 × 3 i.e., 3 × 3 matrix. Proof: Since $\alpha \neq \epsilon$ we must have that $\mathrm{order}(\alpha) \geq 2$ . $\begin{bmatrix} 8 & a & 5\\ -3& 15 & b \end{bmatrix}$ The order of the above matrix is (2×3), since the number of rows (m) = 2 and the number of columns (n) = 3. Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.. asked Nov 17 '19 at 9:11. The order (or dimensions or size) of a matrix indicates the number of rows and the number of columns of the matrix. (1, 2, 3) . Up to equivalence, there is a unique Hadamard matrix of orders 1, 2, 4, 8, and 12. vertical lines of elements are said to constitute columns of the matrix. Here, M ij is the minor of a ij th element of the given matrix. Balbharati Solutions; NCERT Solutions; RD Sharma Solutions; RD Sharma Class 10 Solutions; RD Sharma Class 9 Solutions; Lakhmir Singh Solutions; HC Verma Solutions; RS Aggarwal Solutions; RS Aggarwal Class 10 Solutions; TS Grewal Solutions; ICSE … MATLAB - Matrix - A matrix is a two-dimensional array of numbers. Method 3: (DFS Recursive Approach) Approach: Another recursive approach is to consider DFS movement within the matrix (right->down->left->up->right->..->end). It is denoted by adj A. Answer. For example, suppose A is a 10 × 30 matrix, B is a 30 × 5 matrix, and C is a 5 × 60 matrix. VIEW SOLUTION. The following matrix has 3 rows and 6 columns. The size and shape of the array is given by the number of rows and columns it contains, called its order.So a matrix with 3 rows and 2 columns is described as having order 3 by 2.This is not the same as a matrix of order 2 by 3, which has 2 rows and 3 columns." Maths. Sometimes there is no inverse at all. Find the matrix M such that 5M + 3I = 4[(2, -5),(0, -3)] VIEW SOLUTION. Free PDF Download of CBSE Maths Multiple Choice Questions for Class 12 with Answers Chapter 3 Matrices. Click hereto get an answer to your question ️ If A is any square matrix of order 2 , then adj ( adj A ) = LEARNING APP; ANSWR; CODR; XPLOR; SCHOOL OS; answr. If I is the unit matrix of order 2 x 2. Exercise 9 (B) | Q 10.2 | Page 122. Misc 11 Find the matrix X so that X [ 8(1&2&3@4&5&6)] =[ 8(−7&−8&−9@2&4&6)] X [ 8(1&2&3@4&5&6)] = [ 8(−7&−8&−9@2&4&6)] X [ 8(1&2&3@4&5&6)]_(2 × 3) = [ 8(−7&−8&−9@2&4&6)]_(2 × 3) So X will be a × matrix Let X =[ 8(&@&)]_(2 × 2) So, our equation becomes [ 8(&@&)] (टीचू) Maths; Science; GST; Accounts Tax; Englishtan. If we multiply a 2×3 matrix with a 3×1 matrix, the product matrix is 2×1 \begin{bmatrix} r_{11} & r_{12} & r_{13}\\ r_{21} & r_{22} & r_{23}\end{bmatrix} × \begin{bmatrix} c_{11} \\ c_{21} \\ c_{31} \end{bmatrix} = … If [(1, 4),(-2, 3)] + 2M = 3[(3, 2),(0, -3)], find the matrix M . Concept: Matrices Examples. The graphics software uses the concept of a matrix to process linear transformations to render images. … Textbook Solutions. Login. Transcript. 4,893 2 2 gold badges 9 9 silver badges 33 33 bronze badges. If A is any square matrix o... maths. If the R.H.S., namely B is 0 then the system is homogeneous, … "A matrix is a rectangular array of numbers. Here is the definition: The inverse of A is A-1 only when: A × A-1 = A-1 × A = I. Let us try an … B. det A. C. A − 1. … Time Complexity: O(m*n). Adjoint of square matrix A of order 3 is given below : Find the adjoint of the following matrices : Example 1 : Solution : Example 2 : Solution : Example 3 : Solution : Apart from the stuff given above, if you need … By using this website, you agree to our Cookie Policy. It can be calculated using various methods. Solutions Graphing Practice; Geometry beta; Notebook Groups Cheat Sheets; Sign In; Join; Upgrade; Account Details Login Options Account Management Settings Subscription Logout No new … So the given matrix is 1 x 2 We match the 1 st members (1 and 7), multiply them, likewise for the 2 nd members (2 and 9) and the 3 rd members (3 and 11), and finally sum them up. Therefore, X has to be a 2 × 2 matrix. On the Basic Theorems Regarding Transpositions we proved that for any transposition $\alpha = (ab)$ that: Ex 3.2, 22 (Introduction) Assume X, Y, Z, W and P are matrices of order 2 × n, 3 × k, 2 × p, n × 3 , and p × k respectively. If I is the unit matrix of order 2 x 2 Find the matrix M such that M - 2I = 3[(-1, 0),(4, 1)] VIEW SOLUTION. By convention, rows are listed first; and columns, second. Then |A-λI| is called characteristic polynomial of matrix. Let "M" xx [(1, 1),(0, 2)] = [1 2] where M is a matrix. Given (i) M is the order of 1 x 2 let M = [x y] ∴ [(x , y)] xx [(1, 1),(0, 2)] = [(1 , 2)] ⇒ [(x + 0 , x + 2y)] = [(1 , 2)] Comparing … Give an example of a 5 x 7 matrix A with nullity(A) = 2 and an example of a 5 x 7 matrix A with nullity(A) = 7. linear-algebra matrices matrix-rank. Let A be a square matrix of order n. The adjoint of square matrix A is defined as the transpose of the matrix of minors of A. Let MM×[1102] = [1 2] where M is a matrix. the given matrix is 1 x 2 The order, or dimension, of a matrix is the number of rows and columns that a matrix has. The dot product is performed for each row of A and each column of B until all combinations of the two are complete in order to find the value of the corresponding elements in matrix C. For example, when you perform the dot product of row 1 of A and column 1 of B, the result will be c 1,1 of matrix C. The dot product of row 1 of A and column 2 of B will be c 1,2 of matrix C, and so on, as shown in the example … In order to find the inverse matrix, use row operations to convert the left side into the identity matrix. No extra space is required. Thus, the value of for a column matrix will be 1. For example, the rank of the below matrix would be 1 as the second row is proportional to the first and the third row does not have a non-zero element. A matrix having only one column is called a column matrix. If matrix A = (9, 1, 7, 8) matrix B = (1, 7, 5, 12) find matrix C such that 5A + 5B + 2C is a null matrix. Find the vertex of the parabola. Learn more Accept. They contain elements of the same atomic types. Then system of equation can be written in matrix form as: = i.e. Question 1: If A = [1 2 3], then order is. A matrix is a two-dimensional data structure where numbers are arranged into rows and columns. A 2×2 determinant is much easier to compute than the determinants of larger matrices, like 3×3 matrices. Show that a 5 x 7 matrix A must have 2 $\leq$ nullity(A) $\leq$ 7. English Speaking; Grammar; Resume Help; Email help; … Find the Inverse [[1,2,3],[4,5,6],[7,8,9]] Set up a matrix that is broken into two pieces of equal size. 12th. Given `[(2, 1),(-3,4)] X = [(7),(6)]. A matrix having m rows and n columns is called a matrix of order m × n or simply m × n matrix (read as an m by n matrix). Order of Multiplication. Exercise 9 (C) [Pages 129 - 131] Selina … To find a 2×2 determinant we use a simple formula that uses the entries of the 2×2 matrix. Adjoint of a Matrix. Students can solve NCERT Class 12 Maths Matrices MCQs Pdf with Answers to know their preparation level. SBI! (i) State the order of matrix M (ii) Find the matrix M. Solution Show Solution. Free matrix calculator - solve matrix operations and functions step-by-step. To traverse the matrix O(m*n) time is required. Though we Write 1) The Order of the Matrix X 2) The Matrix X. On the left side, fill in the elements of the original matrix. Recent Articles. a d j (a d j A) = ∣ A ∣ n − … Millions of inequivalent matrices are known for orders 32, 36, and 40. Then, Dec 03, 20 07:16 AM. Theorem 2: If $\alpha = (ab)$ is a transposition of $\{ 1, 2, ..., n \}$ then $\mathrm{order} (\alpha) = 2$. Well, for a 2x2 matrix the inverse is: In other words: swap the positions of a and d, put negatives in front of b and c, and divide everything by the determinant (ad-bc). 2×2 determinants can be used to find the area of a parallelogram and to determine invertibility of a 2×2 matrix. D. None of these. Another example of the row matrix is P = [ -4 -21 -17 ] which is of the order 1×3. R - Matrices - Matrices are the R objects in which the elements are arranged in a two-dimensional rectangular layout. We do this by modifying the matrix itself such that when DFS algorithm visits each matrix cell it’s … Determinants. Matrix calculus generalizes classical analytical notions such as derivatives and exponentials to higher dimensions. Shreyash Tatia Shreyash … 2x2 Matrix. Definition. However, the order in which we parenthesize the product affects the number of simple arithmetic operations needed to compute the product, or the efficiency. Sum of all three four digit numbers formed using 1, 2, 5, 6. copyright onlinemath4all.com. It can be large or small (2×2, 100×100, ... whatever) It has 1s on the main diagonal and 0s everywhere else; Its symbol is the capital letter I; It is a special matrix, because when we multiply by it, the original is unchanged: A × I = A. I × A = A. Hence, we can say that if the number of elements in a matrix be prime, then it … Advertisement. In general, an m × n matrix has the following rectangular array; If A = [1 2 3], then order is? Question By default show hide Solutions. [ 2 29 5 29 3 29 − 7 29 ] [ 7 5 3 − 2 ] [ x y ] = [ 2 29 5 29 3 29 − 7 29 ] [ 3 22 ] If A is any square matrix of order 2, then a d j (a d j A) = A. After this is complete, the inverse of the original matrix will be on the right side of the double matrix. We know that. 3 × 2; 3 × 1; 2 × 2; 1 × 3 3.1.2 Order of a Matrix A matrix having m rows and n columns is called a matrix of order m × n or simply m × n matrix (read as an m by n matrix). (7, 9, 11) = 1×7 + 2×9 + 3×11 = 58. of the equation is a 2 × 3 matrix. Mcqs PDF with Answers PDF Download was Prepared Based on Latest Exam Pattern each side of the order ×... On each side of the double matrix \leq $nullity ( a ) a. The row matrix of the original matrix will be on the left side fill! 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## order of a matrix 2 5 7 is
Dark Turquoise Hair, Why Is The Sumatran Rhino Endangered, Sanderling Fun Facts, How Much Plastic Is Recycled In Australia, What Is Brixx Haribo, Jetblue Mosaic Number, Fit Acceptance Rate, Red Flowers In Minnesota, The Looney Tunes Show, Oppo Udp-203 For Sale Canada, | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8500051498413086, "perplexity": 730.3842723588969}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243992721.31/warc/CC-MAIN-20210513014954-20210513044954-00140.warc.gz"} |
https://mathoverflow.net/questions/344675/why-does-this-matrix-have-zero-determinant | Why does this matrix have zero determinant?
This curious identity arose from studying reductions of the maximal ideal in certain monomial algebra. It can be proved "by hand", (i.e, using Macaulay 2), but I am seeking a more conceptual understanding and related references if they exist.
Let $$R$$ be a commutative ring. For two vectors $$v=(a,b,c,d), w=(A,B,C,D)\in R^4$$, we define $$v\star w:= (aA,aB+bA,bB, cC,cD+dC,dD)\in R^6$$. Given any 3 vectors $$v_1,v_2,v_3\in R^4$$, we can form a $$6\times 6$$ matrix $$M$$ whose rows are $$v_i\star v_j$$, $$1\leq i,j\leq 3$$. Then: $$\det(M)=0$$
It is not clear to me how to explain this. The kernel of $$M$$ is a column of degree $$6$$ polynomials, so the relations are quite complicated.
Question: Is there a way to conceptually explain the vanishing of $$\det(M)$$? Have you seen similar identities?
Three vectors $$v_1,v_2,v_3$$ lie in a hyperplane $$H:\alpha x+\beta y+\gamma z+\delta t=0$$, in this plane we have $$Q(v,v):=(\alpha x+\beta y)^2-(\gamma z+\delta t)^2=0,\forall v\in H$$. Thus by polarization $$Q(v,w)=\frac 14 (Q(v+w,v+w)-Q(v-w,v-w))=0$$ for all $$v,w\in H$$ that yields a relation between columns of your matrix: if $$v=(a,b,c,d), w=(A,B,C,D)$$, then $$Q(v,w)=\alpha^2 aA+\beta^2 bB+\alpha\beta(aB+bA)-\gamma^2 cC-\delta^2 dD-\gamma\delta(cD+dC)$$.
• So in other words you are saying that the vector $(\alpha^2,\alpha\beta,\beta^2,-\gamma^2,-\gamma\delta,-\delta^2)$ is in the kernel of the matrix. Since the $\alpha,\beta,\gamma,\delta$ are cubic in the vectors $v_1,v_2,v_3$, this explains the degree $6$ polynomials. – Zach Teitler Oct 27 '19 at 8:40 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 19, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9822824001312256, "perplexity": 93.0557055689636}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250613416.54/warc/CC-MAIN-20200123191130-20200123220130-00479.warc.gz"} |
https://www.genevo.com/fi/how-lidar-laser-works/ | ### How does laser speed measurement actually work?
The police officer choose the vehicle he wants to measure in the laser guns viewfinder. Then he presses the trigger and the laser sends impulses in the invisible-infrared part of the spectrum against this vehicle. The beam is emitted in very short intervals - pulses. If we aim the laser beam at a shiny object, it will be reflected back from it - Instantaneously. The reflected beam is captured by optics and a light-sensitive element - a photodiode - converts it into an electrical signal.
Based on the length of the pulse return time, the lidar calculates the distance to the object. The ratio of the distance traveled to the elapsed time is calculated from the average of several measurements, and the radar calculates the speed based on these values. The measuring point is most often the headlight, mask, or registration plate, which tends to be very shiny. By pressing the trigger, the device is activated and the vehicle's speed is measured within about one to two seconds. The speed data will immediately appear on the display.
The laser is able to measure the vehicle up to a distance of 1 km, but by default, it is measured at a distance of 50-400 meters. A light-colored vehicle is easier to measure with lasers than a dark-colored vehicle. The technical parameters of laser pistols used in Europe vary in each country.
A portable radar detector can detect laser guns, however, it usually does not provide enough time for safe deceleration, more about how radar detectors and anti-radars work can be found here. The only 100% protection against laser speed measurement is an active laser jammer. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8393813371658325, "perplexity": 1038.1800407676553}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500151.93/warc/CC-MAIN-20230204173912-20230204203912-00134.warc.gz"} |
https://trac-hacks.org/ticket/5333 | Opened 9 years ago
Closed 8 years ago
# [0.11] exception in expat - "junk after document element
Reported by: Owned by: col Alec Thomas normal XmlRpcPlugin normal 0.11
Should the trunk build work with 0.11.2.1?
I installed from trunk, the http://user:passwd@trac/project/login/xmlrpc seems to work "sometime" - the sample code to return the list 1 time in about 10. The failure is an exception in expat - "junk after document element: <differing line and col numbers here>"
This plugin would be very helpful if we can make it work, but where to start?
### Attachments (1)
tractest.py (868 bytes) - added by col 9 years ago.
### comment:1 follow-up: 2 Changed 9 years ago by Steffen Pingel
Description: modified (diff) problems with 0.11? → [0.11] exception in expat - "junk after document element
Can you provide more details how you are using the XmlRpcPlugin?
### comment:2 in reply to: 1 Changed 9 years ago by col
Can you provide more details how you are using the XmlRpcPlugin?
Yeah, sorry my original description isn't up to much. Installed the plugin for all environments following the instructions.
set the XML_RPC to anonymous, but also testing using a trac_admin user... so my tests:
• gave TICKET_CREATE to anonymous.
• did a ticket create test. using the http://trac/projects/demo/xmlrpc worked fine. :-) why didn't I just do that before?
• using my attached python prog with the login version results in:
C:\projects\tractest>python tractest.py Unexpected error. Gonna raise it. Traceback (most recent call last):
File "tractest.py", line 20, in <module>
id = server.ticket.create( "TestTracTicket", "manually created ticket via xmlrpc interface")
File "c:\python26\lib\xmlrpclib.py", line 1199, in call
return self.send(self.name, args)
File "c:\python26\lib\xmlrpclib.py", line 1489, in request
verbose=self.verbose
File "c:\python26\lib\xmlrpclib.py", line 1253, in request
return self._parse_response(h.getfile(), sock)
File "c:\python26\lib\xmlrpclib.py", line 1387, in _parse_response
p.feed(response)
File "c:\python26\lib\xmlrpclib.py", line 601, in feed
self._parser.Parse(data, 0)
xml.parsers.expat.ExpatError: junk after document element: line 10, column 0
I think it's looking like an authentication problem... anything else I can do let me know.
col
### comment:3 Changed 8 years ago by Odd Simon Simonsen
Description: modified (diff) → worksforme new → closed
Hard to say, but could well be authentication. That username looks like it is using some non-basic form of authentication, and the plugin only supports Basic Auth - see XmlRpcPlugin documentation.
Problem with the version of plugin you used was that on any 'big' error like authentication, the plugin would raise a regular Trac error - which in turn makes a nice HTML page of information. That result cannot be parsed by the xmlrpclib and it complains of about junk in result.
In [6069] I re-did the error handling, so that most classes of errors should now return in the format requested by the caller. Please update to latest version of plugin from trunk. Also, turn on Trac debug logging - the plugin writes much useful information to the logs.
Please reopen if you think this is a problem with the plugin, and include the 'About Trac' list of software versions + any other relevant information.
### Modify Ticket
Change Properties | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.19351550936698914, "perplexity": 11408.567353850374}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948569405.78/warc/CC-MAIN-20171215114446-20171215140446-00445.warc.gz"} |
http://www.freemathhelp.com/forum/threads/39246-You-know-what-we-need?goto=nextoldest | # Thread: Features In vBulletin
1. ## Features In vBulletin
#1
On the old system, people wishing to view the LaTex coding in a post would need to click "reply with quote" to see the coding.
Now, we right-click on a LaTex expression, and a context menu appears. Select "Show Math As" and then "Tex Commands".
A new window displays the coding. Try it, below.
$\dfrac{x}{x + 4} = e^{x}$
2. #2
On the old system, one could edit their post without the system appending a post-has-been-edited-by-author notice, as long as nobody had yet replied.
On vBulletin, the system seems to give you a short grace period (a few minutes?) for editing without appending the notice. If you edit after the grace period expires, the system will append the notice regardless of whether someone has replied.
There is a new feature, too.
If you click the post-has-been-edited notice, you'll have an opportunity to compare versions.
3. #3
While composing a message, in-line image attachments can now be dragged-and-dropped to new locations within a post.
This feature is especially handy, when trying to add text below a trailing in-line image, as sometimes the insertion point cannot be moved beyond a trailing in-line image.
In other words, your added text will sometimes be automatically inserted before the image. After adding that text, you may then drag the image to appear before the text, instead.
4. #4
On the old system, when changing text color, one would need to first highlight the text and then open the color menu to select the new color.
On vBulletin, changing the text color for the first time causes the drop-down-menu button's arrow to become highlighted with the "current" color.
This allows one to highlight future text and change to the current color without using the drop-down menu; simply click the letter "A" on the button, and the highlighted text or your new typing will change to the currently-indicated color.
5. #5
We can now upload a "profile picture" that appears whenever someone clicks on our username.
Check out mine! An aquaintance sent it to me; he calls it "Mad Mark", heh, heh.
You upload your picture through the "Settings" link (upper right, next to "Log Out" link).
On the Settings page, look for the link titled "Edit Profile Picture" in the lower box on the left side of the screen.
6. Nice tutorial, Mark.... really appreciate it...
7. Originally Posted by Subhotosh Khan
Nice tutorial, Mark.... really appreciate it...
One is pleased to be of service.
I hope that other users will add their own tips and tricks, too.
8. #6
If you want to delete a previously-attached image, then hover the mouse pointer over the thumbnail in the attached-images section (click the [Manage Attachments] button to get there), and an [X] button will appear in the upper-right corner (as shown below).
delete.jpg
NOTE: The reason why this thumbnail displays my screenshot at "full size" is because I enlarged the display by 200% before taking the screenshot. In other words, I uploaded a huge image; click the image to see the actual size. Uploading huge images is sometimes a workaround to make an in-line thumbnail readable as is. I say "sometimes" because, if your image is too big, vBulletin will shrink it anyway.
EDIT: Ted has since increased the image-size limits. If your image is not larger than 350 pixels in either dimension, then the image will attach at full size (i.e, not as a clickable thumbnail). Larger images attach as thumbnails on which viewers must click to see the full size.
9. Glad to see this list of useful new features. Thanks for the work, mmm444bot!
10. #7
Hovering the mouse pointer over many links or clickable icons provides a pop-up description. If you're not sure what something does or means, try hovering the mouse pointer over it.
For example, hover the mouse pointer over the dot to the right of my username in this post (it may be a small green dot or a small open, black circle), and see what happens.
#### Posting Permissions
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https://answers.ros.org/answers/369931/revisions/ | Revision history [back]
robot_upstart can indeed be a helpful package, but due to the issues you encountered I've tended toward making my own systemd service files which gives me full control of how the services are crafted and brought up.
To remove a service previously installed with robot_upstart :
$rosrun robot_upstart uninstall NAME_OF_SERVICE How to modify the launch file that is tied to that service depends on whether the service was initially created with the 'symbolic' flag, in which case you can modify the launch file at the package level (i.e. in your workspace). If you didn't use the symbolic flag, then the launch file was copied when robot_upstart created the service. This lives in /etc/ros/$ROS_DISTRO/NAME_OF_SERVICE.d/
And just for completeness sake, the service files that robot_upstart creates live in /etc/systemd/system/multi-user.target.wants/NAME_OF_SERVICE.service and /lib/systemd/system/NAME_OF_SERVICE.service. The commands you can run to start/stop the service are in /usr/sbin/ with the name NAME_OF_SERVICE-{start/stop}
I'm not sure how you want to "modify the configuration of the service" but I interpret that as a combination of modifying the launch file that's brought up and the service file(s) that bring up the launch file. I've never used robot_upstart to make modifications of the service itself, but instead have manually edited the *.service files to do what I want, i.e. bring the service up after networking, adding delays between services, etc. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3184756934642792, "perplexity": 2735.4621911407303}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304134.13/warc/CC-MAIN-20220123045449-20220123075449-00431.warc.gz"} |
https://davewigglesworth.com/author/davidsethwigglesworth/ | Forecasting With Level VARs Despite Non-Stationarity And/Or Cointegration. Intuition.
Intro
I sometimes run into people who fret about how you can’t use VARs for non-stationary or cointegrated data. For sure, there are problems with frequentist inference and IRFs under these conditions. See Sims, Stock, and Watson (1990) and Phillips and Durlauf (1986).
But for forecasting, a VAR in levels is competitive with a VAR in differences (non-stationary but not cointegrated) or a VECM (cointegrated). There are a few papers with no strong consensus. Christoffersen and Diebold (1998) find that “nothing is lost by ignoring cointegration” with respect to out-of-sample MSE.
Intuition: Non-Stationary, Not Cointegrated
When the data are non-stationary but not cointegrated, an AR in differences can trivially be re-written as an AR(2) in levels.
$y_t - y_{t-1} = \alpha_0 + \beta(y_{t-1}-y_{t-2}) + \varepsilon_t$
$y_t = \alpha_1 + (1+\beta) y_{t-1} - \beta y_{t-2} + \varepsilon_t$
The intercepts may change between the two may change as a function of having different control variables, but the relationship in the slope coefficients actually bares out if you try it with real data (within reasonable OLS margin of error).
The levels-AR(2) has more parameters to estimate, so we might expect that it could perform worse from a variance point-of-view. However, a non-stationary variable is cointegrated with lags of itself, meaning that OLS is super-consistent; i.e. it converges faster than normal to the true coefficients. So, these effects come out in the wash.
Intuition: Non-Stationary, Cointegrated
Yes, cointegration implies non-stationarity, but humor my desire for symmetrical headers. Here, we still have that cointegration implies super-consistency for the VAR in-levels. So whatever information is lost by ignoring the error-correction term is likely to come out in the wash. Similarly, the lagged dependent variable in the VAR in-levels will ensure that the residuals are stationary, which will guard against spurious lagged independent variables; i.e., spuriousness comes from unaccounted non-stationarity, but a lagged dependent variable is an accountant.
I will be following up with some simulation results.
Macro Random Forest Leads To Macro Gains In Macro Forecasting
Tomorrow is the 11th ECB Forecasting Conference.
I am excited to see so many top authors: Sims, Engle, Koop, Marcellino, Schorfeide, and many more.
It is fitting that so many progenitors of the innovative models of yesteryear and workhorse methods of today — VAR, ARCH, and Bayesian macroeconometrics — are here to oversee the next generation, who are forging tomorrow’s method in the fires of machine learning.
One such youngster is Phillippe Goulet Coloumbe, author of Taste #3: “The Macroeconomy As A Random Forest.”
In short, his method uses the usual splitting structure of trees over bootstrapped samples. However, regularized linear equations (e.g. a ridge AR(1)) appears in each terminal node as opposed to the vanilla conditional sample mean. By allowing the regressors — or some super/sub-set of regressors — to dictate the splits of trees, we can capture a myriad of non-linearities. For example, a split on a trend variable can capture the behavior of sharp structural change, and a split on the lagged dependent variable can capture the behavior of regime-switching. Averaging over many such trees incorporates all of these dynamics, approximating a true underlying non-linear structure. In short, it is a clever way to use a common machine learning algorithm to capture common time series dynamics, all in one package.
I use this method at work, often finding that it works pretty well.
Given the recent chatter about a labor shortage and upward pressure on wages, I have been interested in forecasting wage inflation via the Employment Cost Index (Wages & Salaries) year-over-year.
I conduct a pseudo-out-of-sample experiment over the last 20 quarters. For each quarter, I fit a factor-augmented VAR (OLS) and factor-augmented MRF, then forecast ECI one-quarter ahead.
OLS Mean Absolute Error = 0.12
MRF Mean Absolute Error = 0.07
Diebold Mariano-Test, p = 0.003
Data Scientists: Jack of All Trades, Master of One?
There is a popular Venn diagram that purports that data science exists at the intersection of applied statistics, programming, and domain knowledge. Companies would love nothing more than to replace their statistician, software developer, and consultant with one person. Unfortunately, life experience says that very few people can be experts in all three distinct and difficult areas. So, one might say that a data scientist is a “jack of all trades, master of none”.
But in my experience, I find that many data scientists are people who have deep expertise in one area — they are statistics grad students or computer science grad students — who try to reach beyond their discipline’s traditional boundaries to secure the coveted “data scientist” title.
In other words, I would argue that data scientists are “jack of all trades, master of one“.
Take Mike, an econometrics PhD. He has a superior understanding of applied statistics, a pretty good grasp of economic theory (companies will appreciate that he took graduate micro but maybe not care about his electives), and a decent capacity to code (in so far as he needs to program his models and do his empirical work). A lot of data scientists tend to look like Mike: they have a hierarchy of skills.
Nowadays, there are “data science” programs designed so people like Mike do not have to waste their energy pivoting away from a pure econometrics skill set.
Consider Penn’s Data Science MSE. In this program, they douse you in a bit of statistics and a bit of programming. Then they send you off to do electives. I have a feeling that people will choose electives that are somewhat related to one another because it’s natural for people to want to build expertise. But let’s say you take a varied set of electives, as the Venn diagram suggests you should — is that better? I am personally doubtful. Because when the shit hits the fan, a master of none does not have the ability to diagnose problems on a deep level. The master of one will be at least as good on non-expert issues and far superior on expert issues.
Surprise, surprise — expertise still means something.
The Limited Usefulness of Rubin Causality For Decision Makers
I took two courses that explicitly touched on causal inference in college. Both began with the idea that the Rubin average causal effect of treatment D on outcome Y is given by:
$E[Y|X,D=1] - E[Y|X,D=0]$
The idea here is that many things may determine Y. D determines Y, but so do other things (X). If we can estimate the average Y given D=1 versus Y given D=0 while keeping X constant, then we are in business. Luckily, well-specified, squared-loss regressions are good statistical estimators of the conditional expectation function. So if we have a good model that is fully exogenous, all we would have to do is obtain $\hat \beta$ from the following regression:
$Y = \alpha + \beta D + \gamma X + \varepsilon$
In economics, these models often have some endogenous D, so we use instrumental variables, sample selection corrections, matching, etc.
In any case, the Rubin approach can be very useful for solving specific problems. For example, if one can show that race or gender significantly predicts wages while holding other characteristics equal, we have good evidence of discrimination. This is a very direct and practical use for a human resources department trying to keep things fair.
But one can also argue that treating D as orthogonal to X is a sterile approach with a limited normative interpretation. If nearly everyone with D=1 has a different X than those with D=0, then the incremental effect of D=1 may not be of interest to people actually trying to use the research to improve outcomes.
Marriages preceded by a period of cohabitation tend to result in divorce at higher rates than marriages not preceded by cohabitation. This is unintuitive to some because it is reasonable to think that only couples with good cohabitation periods decide to marry; cohabitation serves as a screener for good couples. It turns out that people with less committal personalities generally opt for cohabitation and then ease into marriage later via social convention, while those who are committal tend to go straight for marriage. When researchers statistically isolate personality, they find cohabitation leads to better marriages.
So, if you are one of those couples who are heavily committal, how important is the above for you? You might think that you should cohabitate because, all else equal, it should improve your eventual marriage. But the marginal effect for you, as a committal couple, may be so small that delaying marriage is actually the sub-optimal thing to do. So what is important to you is not the effect of cohabitation or D=1, but D=1 given your personality X.
Excessive attention to the effect of D obscures the usefulness of research to people with known X. Many researchers do and should care about the heterogeneity of the effect of D. Unfortunately, acknowledging heterogeneity does not always make for the punchy (amusingly counter-intuitive ex-ante but almost obvious post-hoc) causality papers that are idolized by “Mostly Harmless Econometrics” fans.
ARIMA For Options Investing
In many intro time series classes, you come across the autoregressive integrated moving average (ARIMA) forecasting technique. But you only took economics or finance so you can infiltrate the capitalist beast and make out like a tapeworm. How does ARIMA make my bank account go arriba?
A lot of people fail when trying to use ARIMA to day-trade or swing-trade, so they instead opt for training a neural network with 1 million billion trillion parameters, increasing their electricity bill beyond whatever returns they may hope to make. But if you have patience, if you can suffer through the existential pain that is another year or two on this blighted rock, you may prefer this easier ARIMA options.
1. Pick a stock deemed fairly safe.
2. Download monthly price data. There is a trade-off in periodicity. Daily/weekly data is noisy, and quarterly/annual data leads to issues with estimation and structural change. I think monthly is a good balance.
3. Choose an interval that has fairly linear price action – or price action that can be made linear with log or Box-Box transformations.
4. Forecast 1-3 years out.
5. Find an option that capitalizes on those forecasts while fitting your risk-reward tolerance.
Example: MSFT
> r <- auto.arima(y, seasonal = FALSE)> rSeries: y ARIMA(1,2,2) Coefficients: ar1 ma1 ma2 0.5817 -1.8075 0.8448s.e. 0.1891 0.1126 0.1038sigma^2 estimated as 49.56: log likelihood=-209.05AIC=426.11 AICc=426.81 BIC=434.61> forecast(r) Point Forecast Lo 80 Hi 80 Lo 95 Hi 95May 2021 264.3469 255.3247 273.3692 250.5486 278.1453Jun 2021 268.8622 257.4521 280.2723 251.4120 286.3125Jul 2021 274.3771 261.4216 287.3326 254.5634 294.1908Aug 2021 280.4733 266.2047 294.7420 258.6513 302.2954Sep 2021 286.9078 271.3407 302.4749 263.0999 310.7156Oct 2021 293.5389 276.5900 310.4879 267.6178 319.4601Nov 2021 300.2845 281.8231 318.7459 272.0503 328.5187Dec 2021 307.0966 286.9715 327.2217 276.3180 337.8753Jan 2022 313.9475 292.0015 335.8935 280.3840 347.5110Feb 2022 320.8209 296.8991 344.7426 284.2357 357.4060Mar 2022 327.7073 301.6615 353.7532 287.8736 367.5410Apr 2022 334.6014 306.2913 362.9115 291.3049 377.8979May 2022 341.4999 310.7940 372.2058 294.5393 388.4605Jun 2022 348.4010 315.1759 381.6261 297.5876 399.2145Jul 2022 355.3036 319.4434 391.1639 300.4601 410.1472Aug 2022 362.2071 323.6025 400.8117 303.1664 421.2478Sep 2022 369.1111 327.6588 410.5634 305.7153 432.5069Oct 2022 376.0154 331.6173 420.4134 308.1144 443.9163Nov 2022 382.9198 335.4825 430.3571 310.3707 455.4689Dec 2022 389.8243 339.2584 440.3903 312.4903 467.1584Jan 2023 396.7289 342.9483 450.5096 314.4786 478.9793
Let’s be conservative and check out options for Jan 2023, assuming it hits the lower 80% interval, $343 (no, I am not assuming this is the lower 10th percentile in some posterior distribution, you Bayesian bastards). I am liking the 330/335 Bull Call Spread option below. Assuming MSFT is at least$330 in Jan 2023 (which is probably conservative based on the model), 510% is a good return.
In the name of risk aversion, I am also happy with the 285/290 call spread. MSFT must be at least \$286 in Jan 2023 (only about 10% up from today), and we get a 252% return. Beats the hell out of any savings account I know of.
Be sure to diversify.
Academia vs Industry: In Pursuit of Truth and Story
In industry, reduced-form economic models need to be simple and understandable. Assume your audience is passively familiar with regression from that one stats course in college around the time they realized beer bongs do not go well with their lexapro. Take your target $Y$ and regress on predictors $X$ via OLS. $X$ is a few select predictors – sometimes leading/lagged, mostly not – and tell a story. Therefore, to forecast the future, you need to introduce exogenous estimates of future $X$. They can come from consensus, guts, another model (not simultaneously estimated), wherever. Anywhere but inside the model itself — unless you for some reason have an arbitrary term lagged by 8 months. By the way, cointegrated variables must all be in regressed differences without an error-correction term.
When this works, it really works well. We have a killer treasury bond model that is pretty accurate and quantifies relationships that most investors will understand in a way that confirms their priors about supply and demand or something like that. Use your regular OLS standard errors, even when blatantly inappropriate. A high $R^2$ makes you look like a genius; what is over-fitting?
In academia, you have an opposite problem. You are trying to approximate an unknown and unknowable data-generating process. You are interested in the joint relationship of $Y | X$, which are both random variables. You use squared-error-loss regression techniques because you want an estimate of $E(Y|X)$ — either to make predictions or make statements about causality within that system. You know you will never quite get the true data-generating process, so always take predictions and causal inferences with some grain of salt – “all models are wrong, but some are useful.” And despite this Sisyphean effort – where I acknowledge I do not know and cannot know the true data-generating process – I can say with 100% certainty that your model is problematic. Your model suffers from unchecked heteroskedasticity, autoregressive conditional heteroskedasticity, spatial heteroskedasticity, serial correlation, cointegration, sample selection bias, simultaneity bias, omitted variable bias, measurement error, naive priors, and an inefficient estimator. But it’s okay — because reasonable people can disagree about something unknown and unknowable; the same way people reasonably disagree about God.
When this works, it also really works well. There are asymptotic properties that can steer you into the right direction. Those should be taken to advantage. I do not know how to truly define the concept of physical health, but I know that Michael Phelps is healthier than Artie Lang. And if enough people can come to this conclusion with their subjective feelings about health, it probably is true.
Like an enlightened centrist, I want combine these worlds. One goal I have is to loosen the stigma around lagged variables, especially dependent variables.
I love the Wold Representation Theorem because it mathematically formalizes something very intuitive: the past can predict the future. Any stationary time series (if not stationary, it can be made stationary through differences) can be written using a deterministic term and stochastic term, which is a linear function of it past errors.
$y_t = \eta_t + \sum_k b_k \varepsilon_{t-k}, \ \ k = 1,2,3...$
Often, more recent observations are more useful for prediction than those in the distant past. Hence, the beauty of the AR process.
$y_t = \phi_0 + \phi_1 y_{t-1} = \frac{\phi_0}{1 - \phi_1} + \sum_k \phi_1^k \varepsilon_{t-k}, \ \ k = 1,2,3..., \ \ -1 < \phi_1 < 1$
Generalize this idea to multivariate systems and you are on your way to a Nobel Prize (I love Sims, don’t hurt me).
Industry: But this makes things hard to interpret?
Somewhat. But I think this is how impulse response functions become useful. A one-unit change to $y_1$ j periods ago affects $y_2$ today by $\Psi$. There may be a lot to keep track of, but the interpretation is nice. Be careful about ordering if you use Cholesky decomposition.
Industry: But isn’t a lagged dependent variable just a way of saying “I could not find a real relationship with other variables”?
It’s easy to say that if you are just using ARIMA. But if you use a VAR, if $y_1$ is a function of $y_2$ and $y_2$ is a function of old, then $y_1$ is a function of old $y_2$ too.
Academics: Did you account for cointegration? Run a VECM.
This is where I start to get sympathetic to industry. I know a lot of brilliant economists who took a while to wrap their heads around cointegration. A VAR in levels is still statistically consistent (one would rather run the VAR in levels than a VAR in differences without the EC term). The short-run vs. long-run interpretation is not in the vanilla VAR, but I am not sure if the marginal benefits outweigh the costs. It should be easy to convince clients that the past matters for predicting the future. It is far less easy to convince them that because your non-stationary variables can be written as a stationary linear combination, you need this special term that may or may not substantially improve predictions. You probably can convince them that relationships tend to regress to a long-run equilibrium but probably do not care about “by how much.”
What is the point here? Industry people are smarter than you think. The soft bigotry of low GPAs must end. You don’t have to assume they are experts – that is why they come to you. But if you can provide a better service in a way that people can understand, do it.
VARs in R
I am somewhat irked by the lack of a comprehensive R package for multivariate time series. Rob Hyndman’s forecast/ fable package is an excellent, if not exhaustive (how could it really be?), resource for univariate time series.
Here, I am collecting a list of packages that work multivariate time series models, particularly vector autoregressions (VARs).
vars: Standard frequentist VARs and Sturctural VARs (SVARs). Normal VARs are estimated equation-by-equation by least squares, so a “varest” object is basically a collection of “lm” objects that pull from a common data matrix. The “VARselect” function is very useful for lag order selection via information criteria. Includes useful statistical tests for residual serial correlation, normality, and autoregressive conditional heteroskedasticity.
urca: Unit Root and Cointegration Analysis. Useful implementations of the Johansen cointegreation test and estimation of vector error correction models (VECMs). The “vec2var” function converts a VECM to its equivalent VAR representation.
BVAR: Straight-forward estimation and forecasting of Bayesian VARs with customizable, Minnesota-type priors. Hierarchical estimation in the fashion of Giannone, Lenza & Primiceri (2015).
bvarsv: Computes Bayesian VARs with stochastic volatility and time-varying parameters.
tvReg: The function “tvVAR” implements a time-varying-parameters VAR using kernel smoothing.
HDEconometrics: Allows for easy estimation via LASSO through “ic.glmnet” and “HDVar”.
More to come. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 22, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47572559118270874, "perplexity": 1996.5661312370087}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320303917.24/warc/CC-MAIN-20220122224904-20220123014904-00025.warc.gz"} |
https://physics.stackexchange.com/questions/136080/entanglement-g2-experiment-what-components-do-i-need | # Entanglement $g^{(2)}$ experiment - what components do I need?
I would like to measure whether my source emits entangled photon pairs. To that order I want to build a $$g^{(2)}$$ experiment, which measures photon coincidence counts as a function of time delay between photon detection.
Unfortunately, there is no one here who can show me how. Are there any books or papers that specify what components I need and why? I imagine that it must be much more complicated than hooking up two detectors to my source via fiber optics, right?
Also any hints at how to approach such a setup would be much appreciated. (I'm a first year grad student with next to no supervision.)
• Of course I have been to the library and conducted Internet research. :) I just wasn't successful and was hoping someone could point me in the right direction. Are there any books at all that talk about how to set up such experiments or am I supposed to learn from knowledgable colleagues (that I don't have)? How does this work? So far papers seem to be more about the results than about the methods. – photongirl Sep 19 '14 at 18:37
• This is not helpful and I don't like your tone. – photongirl Sep 19 '14 at 22:08
• It is true that it's difficult to find descriptions regarding basic experimental setup and tuning in quantum optics papers in general. Papers that describe their setups for doing more advanced experiments never go through the detailed steps required for alignment or where/how to purchase the right stuff. It is of course implicitly assumed that whoever is reading those things work in the field and know the basics :) I do think it might be easiest to discuss in person with someone at a local physics lab. – BjornW Sep 20 '14 at 9:50
• Many papers do make it sound like it's a relatively straightforward measurement (see e.g. this example) but conclusive $g^{(2)}(0)<1$ measurements are still hard even in the best-equipped labs around. (I have heard from O'Brien that every Mandel dip observation is considered a significant triumph, often requiring several months of effort.) The reason is that 'indistinguishable' really means indistinguishable in every way, including perfect spatial and temporal mode matching, and that's never a trivial pursuit. – Emilio Pisanty Nov 9 '15 at 13:06
• I don't know whether the problem is still pending, but you could search the literature for Hanbury Brown and Twiss setups and experiments. – jkalden Feb 21 '17 at 12:59 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 1, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5583216547966003, "perplexity": 439.1397140058124}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487634616.65/warc/CC-MAIN-20210618013013-20210618043013-00490.warc.gz"} |
https://link.springer.com/article/10.1023%2FA%3A1006165531180 | Acta Applicandae Mathematica
, Volume 56, Issue 2–3, pp 139–153
# The ‘Three-Line’ Theorem for the Vinogradov C-Spectral Sequence of the Yang–Mills Equations
• Dmitri Gessler
Article
## Abstract
The Vinogradov C-spectral sequence for the Yang–Mills equations is considered and the ‘three-line’ theorem for the term E1 of the C-spectral sequence is proved: E1 p,q = 0 if p > 0 and q < n − 2, where n is the dimension of spacetime.
nonlinear differential equations spectral sequences Spencer cohomology Yang–Mills equations
## Preview
### References
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## Authors and Affiliations
• Dmitri Gessler
• 1
1. 1.School 53MoscowRussia | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9534335136413574, "perplexity": 5016.36664888535}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084887692.13/warc/CC-MAIN-20180119010338-20180119030338-00206.warc.gz"} |
https://socratic.org/questions/what-is-the-equation-of-the-normal-line-of-f-x-5x-3-2x-2-3x-1-at-x-8 | Calculus
Topics
# What is the equation of the normal line of f(x)=5x^3-2x^2-3x-1 at x=-8?
Jul 30, 2017
Equation of normal is $x + 989 y + 2635693 = 0$
#### Explanation:
At $x = - 8$, $f \left(x\right) = 5 {\left(- 8\right)}^{3} - 2 {\left(- 8\right)}^{2} - 3 \left(- 8\right) - 1$
$= - 2560 - 128 + 24 - 1 = - 2665$
Hencewe are seeking normal at $\left(- 8 , - 2665\right)$
Slope of tangent is given by $f ' \left(- 8\right)$ and as $f ' \left(x\right) = 15 {x}^{2} - 4 x - 3$
slope of tangent is $15 {\left(- 8\right)}^{2} - 4 \left(- 8\right) - 3 = 989$
and hence slope of normal is $- \frac{1}{989}$ and
equation of normal is $y + 2665 = - \frac{1}{989} \left(x + 8\right)$
or $x + 989 y + 2635693 = 0$
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https://infoscience.epfl.ch/record/120289 | Infoscience
Journal article
# Reconstruction of ion temperature profiles from single chord NPA measurements on the TCV tokamak
The flux of charge exchange ( CX) neutrals measured by neutral particle analysers ( NPAs) is the line integral along the viewline of the NPA and contains information about the ion energy distribution of the observed plasma. On the Tokamaka a Configuration Variable ( TCV) a single chord NPA is used to scan the plasma cross section by vertically displacing a reproducible discharge across its fixed line of sight. The ion temperature inferred from the passive CX flux as a function of the distance of the NPA chord to the magnetic axis is used to obtain an ion temperature profile T-i(rho). To model the neutral source, simulations of neutral particle penetration from the edge and the neutralization processes are reported. In plasmas with thermalized ion populations, the NPA hydrogen or deuterium temperature profiles agree with the carbon ion temperature profile measured by charge exchange recombination spectroscopy. Matching the simulation with synchronous NPA measurements of two plasma species provides absolute profiles of neutral particles densities and the isotopic composition of the plasma, which are required for the transport analysis. With further modelling, the ion temperature profile may be iteratively reconstructed from the CX spectrum without displacing the plasma. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9412274360656738, "perplexity": 2537.6224427601114}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463608652.65/warc/CC-MAIN-20170526090406-20170526110406-00333.warc.gz"} |
https://www.physicsforums.com/threads/power-efficiency-problem.106717/ | # Power efficiency problem
1. Jan 14, 2006
### endeavor
A 3.25 * 103-kg aircraft takes 12.5 min to achieve its cruising altitude of 10.0 km and cruising speed of 850 km/h. If the plane's engines deliver, on the average, 1500 hp of power during this time, what is the efficiency of the aircraft engines?
I initially believed the power out would be: (Kinetic energy + Potential energy)/Time
And efficiency would be 1500hp/power out. But after my calculations, I got 14.6% efficiency, when it should be 48.7% efficiency.
What did I do wrong?
2. Jan 14, 2006
### Pengwuino
I calculated 48.8% efficiency.
Did you....
1) Change minutes to seconds?
2) Change km to m?
3) Change km/h to m/s?
4) Convert J to hp? ( 735.498 75 watt = 1hp/s)
You have to do each of those in this problem.
3. Jan 14, 2006
### Gamma
Check your units. Did you convert the power in hp to watts?
1 hp = 746 watts.
4. Jan 14, 2006
### Gamma
Looks like we typed at the same time.
5. Jan 14, 2006
### endeavor
I don't know what I did wrong.
I'm pretty sure I converted everything.
It must have been a calculation error, because I just got the right answer. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8278549909591675, "perplexity": 4476.5378758406405}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281162.88/warc/CC-MAIN-20170116095121-00316-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://midlandspunter.com/article/agricultural-and-biological-sciences-an-overview | # Agricultural and Biological Sciences - an overview (2022)
Journal of Guangxi Agricultural and Biological Science 27 (Sup): 53–56.
From:
## Soil organic carbon in sandy soils: A review
Jenifer L. Yost, Alfred E. Hartemink, in Advances in Agronomy, 2019
### 2.5 SOC studies in sandy soils
Over 32,000 papers have been published on sandy soils between 1914 and 2017 (Scopus data; Fig. 3). Approximately 37% of the papers were from the agricultural and biological sciences, 21% from environmental science, and 15% were from earth and planetary sciences (Scopus data). In the past 10 years, some 1000 to 1800 papers are annually published on sandy soils. Of these, about 25–70 papers each year focus on SOC in sandy soils, and the number of papers on SOC and sandy soils is doubling every 10 years.
We extracted papers since the early 1990s, and grouped them by continent, climate zone, land cover, soil order, and focus of the research. The papers included soils with a minimum sand content of 600gkg−1. Most research on sandy soils has been conducted in Europe and in Africa. Fewer studies have been conducted in Asia, South and North America, and Australia. A large portion of the papers were based on research conducted on Entisols, and Spodosols were the second most studied soil order. Most papers were based on research conducted on sandy soils under agriculture or forest.
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URL:
https://www.sciencedirect.com/science/article/pii/S0065211319300720
## An Evolutionary Perspective on Industrial and Sustainable Agriculture
John Gowdy, Philippe Baveye, in Agroecosystem Diversity, 2019
### Alternative Paths
Agroecology can be considered the overarching scientific framework for developing specific alternatives to industrial agriculture. According to Altieri and Nicholls (2015), “Agroecology is a science that draws on social, biological and agricultural sciences and integrates these with traditional knowledge and farmers' knowledge. … At the heart of the agroecology strategy is the idea that an agricultural system should mimic the functioning of local ecosystems, thus exhibiting tight nutrient cycling, complex structure and enhanced biodiversity.”
Agroecology applies ecologic principles to food production systems. It does not reject all technology but attempts to minimizes or eliminate pesticides, commercial fertilizers, and monoculture. It is multidisciplinary in the sense that it focuses on both the biologic and social aspects of agriculture. It focuses on four properties of agriculture systems: productivity, stability, sustainability, and equity. Especially important to this field is the incorporation of indigenous farming practices (Garí, 2001). Perhaps the most important feature of agroecology is its insistence on the integration of ecologic and social science principles in the study of agricultural systems (Dalgaard etal., 2003).
Agroecology is not a “solution” but rather a generic framework for evaluating specific local and diverse approaches (Wezel etal., 2009). Within this framework, several promising developments are taking hold. A few examples are the following.
The local food movement: One of the most successful social movements in recent decades is community supported agriculture (CSA). CSAs have many different forms, but the focus is on high quality, low environmental impact, and local farming. They depend on direct contracts between consumers and local farmers. The basic feature of a CSA is consumers who are willing to commit to buying a whole season's worth of food and farmers who are willing to work with consumers to produce the kinds of crops they want (Kleppel, 2014). According to the US Department of Agriculture, there were 7398 CSAs in the United States in 2015, accounting for 7% of direct to consumer sales by farmers (USDA, 2016).
The ugly food movement: The objective of the ugly food movement is to prevent the waste of perfectly good fruits and vegetables that do not meet the standards of appearance that consumers are used to. The move has been particularly successful in Europe. In 2014 the European Union eliminated regulations prohibiting the sale of odd or misshaped fruits and vegetables. Public information campaigned have been successful by introducing terms like “wonky,” “inglorious,” or “naturally imperfect” to promote ugly food.
http://time.com/3,761,942/why-people-are-falling-in-love-with-ugly-food/.
The healthy food movement: Has more food made people less healthy? A related question is “Is food too cheap?” According to the World Health Organization (WHO), 57 of 129 countries are struggling both with obesity and malnutrition. Eight hundred million people are malnourished worldwide, but over twice that number (2billion) are overweight or obese. The consumption of healthy food (fish, nuts, and vegetables) is declining, and people are eating too much fat, salt, and sugar (Haddad etal., 2016). Government subsidies for sugar and corn have been blamed for much of the decline in food quality. Agricultural research money is disproportionately spent on crops like maize (accounting for 45% of private sector agricultural research spending) compared to research on more nutritious fruits and vegetables. But consumers are having a tremendous effect at the retail level, and this is putting pressure on food distributors and producers to fundamentally change the way food is produced.
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https://www.sciencedirect.com/science/article/pii/B9780128110508000273
## The FUTURE partner network
Jennifer Greenier, ... Lars Berglund, in BEST, 2020
### Introduction
FUTURE is a career exploration program at the University of California, Davis, that was established with funding from the NIH BEST Initiative. The program is administered by the Clinical and Translational Science Center (CTSC) and is now fully supported by the CTSC and the School of Medicine. FUTURE is open to predoctoral graduate students and postdoctoral scholars conducting health-related research across 20 graduate programs and 29 departments in two campuses. Thus far, 131 participants in seven cohorts have enrolled in the program, representing the Schools of Medicine and Veterinary Medicine, and the Colleges of Biological Sciences, Agricultural and Environmental Science, Letters and Science, and Engineering. The centerpiece of the FUTURE program is a 10-week Career Exploration workshop series, which serves as a foundational career preparation experience for newly enrolled participants and as their introduction to a unique feature of our program, the FUTURE Partner Network. The Partner Network comprises Ph.D. professionals in non-faculty careers who contribute to the FUTURE program by sharing their career knowledge and experience with program participants. In this chapter, we'll describe the network, our data management methods, and the interactions between our program partners and participants.
From the inception of the FUTURE program, we recognized that although many trainees know that they do not want to pursue faculty research careers, they have limited knowledge of the diversity of options that are well suited for Ph.D.-trained scientists. Even in cases where they do know about particular careers, trainees often lack knowledge about how to transition into them [1]. Successful transition of Ph.D. trainees into careers of their choice requires insider information about what various careers entail, potential paths to those careers, and the skills needed to pursue them. One way of addressing this need is to connect graduate students and postdocs to Ph.D. scientists working in a broad spectrum of job categories in all major career sectors who can provide insight into interesting and fulfilling careers inside and outside of academia.
Our vision of a career preparation program for graduate students and postdocs included a network of Ph.D. scientists who had successfully navigated non-faculty career paths and who could provide trainees with windows into a variety of professions, from the known and expected to the unknown and unimagined. We aspired to build a community of Ph.D.s in the workforce who would partner with us in this effort, and eventually grow to a critical mass of professionals who adequately represented the diverse career interests of our program participants. We began recruiting partners in the second year of our program, primarily from our own professional contacts and from career-focused campus events, all while experimenting with different strategies for developing and managing our network. By the end of year 4, nearly 100 Ph.D. scientists had joined our FUTURE Partner Network, and we had refined our processes for recruitment, data management, and partner engagement.
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https://www.sciencedirect.com/science/article/pii/B9780128207598000085
## Moringa oleifera through the years: a bibliometric analysis of scientific research (2000-2020)
Toyosi T. George, ... Fannie G. Rautenbach, in South African Journal of Botany, 2021
### 3.2 Global research subjects on Moringa oleifera (2000-2020)
From the data indexed on the Scopus database as represented in Fig.4, agricultural and biological sciences are ahead of the pack in terms of research outputs on MO, accounting for 23.4% of the total number. Other categories that were significantly studied are biochemistry, genetics and molecular biology (11.5%), pharmacology, toxicology and pharmaceuticals (9.9%). Although there are other articles published in different journals in the form of review articles, book chapters, letters to the editor, etc., this study is only limited to original research works as these may give a better representation of the research interests on the plant.
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URL:
https://www.sciencedirect.com/science/article/pii/S0254629921001538
## Agricultural waste: Review of the evolution, approaches and perspectives on alternative uses
Mónica Duque-Acevedo, ... Francisco Camacho-Ferre, in Global Ecology and Conservation, 2020
### 3.3 Distribution of scientific production by subject categories and journals
The evolution of the subject categories within the study of agricultural waste has been changing over the last 65 years. Agricultural and Biological Sciences is the dominant category, in which 1053 articles of the total sample are included (Fig.4). This category occupied the first position throughout the whole period analysed, except for the second period, in which it was moved down by engineering to fourth position. Environmental Sciences, which occupied fifth position in the first period (1931–1965), with only one article, was the second subject category from the second period (1966–1979), with a notable number of articles (1,053), which represented 19% of the published articles (see Figs. 6, 7, 8 and 5).
In relation with these two subject categories, it is important to highlight that from the fourth period (1993–2005) to the fifth period (2006–2018), the highest increase in the number of articles associated with these categories saw a move from 364 in the fourth period to 895 in the last period for the first subject category, and from 150 to 801 for the second category. This means that 76% of the articles belonging to Environmental Sciences and 64% of Agricultural and Biological Sciences have been published in the last 13 years.
The subject category Chemical Engineering occupies third position, and groups 9% of published articles. In fourth and fifth position, with the same percentage (7%) Energy and Engineering categories are found, with 393 and 375 associated documents respectively. These five categories group 3694 articles, an amount higher than the total sample of analysed articles (3,148), this is because this research category incorporates several disciplines that have different perspectives of analysis; therefore, its classification cannot be grouped in only one category. The rest of subject categories group a total of 1764 articles, 56% of the total articles analysed. All the articles of the sample are grouped in 25 of the 27 main subject categories of Scopus (Elsevier, 2017).
The subject categories define the articles in different journals that have special interest on this research issue, although from different points of view. Table 8 shows the 25 main journals that, during the period assessed (1931–2018), have published the scientific production under analysis. A total of 1006 journals have published the 3148 articles analysed on agricultural waste and, in the last 13 years, the number of journals interested in this issue has increased considerably. In the first 13 years (1931–1965), only 11 journals published the scientific production of that period (18 articles). For the second period (1966–1979), 51 journals were added to the list, such that 104 articles of that period were published in 62 journals.
Table 8. Main journals that published articles from 1931 to 2018.
JournalATCTC/AHi (A)Hi (J)SJRCR (A)
1931–19651966–19791980–19921993–20052006–2018
Bioresource Technology98664367.79412512.157(Q1)Netherlands0017(3)1(25)1(70)
Soil Science Society of America Journal48267055.63321472.16(Q1)United States002(16)2(18)24(14)
Biomass and Bioenergy47303264.51241561.072(Q1)United Kingdom0058(1)5(11)2(35)
Soil and Tillage Research40209552.38241171.898(Q1)Netherlands006(8)4(13)10(19)
Plant and Soil38135835.74211631.187 (Q1)Netherlands10(1)03(10)8(10)17(17)
Biology and Fertility of Soils37119932.41201091.187 (Q1)Germany0011(4)3(16)15(17)
Soil Biology and Biochemistry33146544.39231862.448(Q1)United Kingdom0022(3)6(11)11(19)
Journal of Hazardous Materials283933140.46272351.958(Q1)Netherlands00092(2)4(26)
Agronomy Journal2785431.63141131.049(Q1)United States0007(10)14(17)
Communications in Soil Science and Plant Analysis272027.488590.307(Q3)United States00010(9)12(18)
Desalination and Water Treatment271626.009450.377(Q2)United States00003(27)
Nutrient Cycling in Agroecosystems2455423.0814871.060(Q1)Netherlands00012(9)21(15)
Waste Management2499341.38171271.523(Q1)United Kingdom00128(1)104(2)6(21)
Journal of Agricultural and Food Chemistry2367729.43132621.111(Q1)United States3(2)019(3)19(6)29(12)
Atmospheric Environment2257426.09142111.418(Q1)Netherlands000129(1)5(21)
Soil Use and Management2280636.6411690.753(Q1)United States00119(1)17(7)25(14)
Field Crops Research2173434.95141271.703(Q1)Netherlands0075(1)11(9)36(11)
Industrial Crops and Products2057828.90141031.015(Q1)Netherlands000182(1)8(19)
Journal of Cleaner Production2021610.80111501.620(Q1)Netherlands00007(20)
Revista Brasileira de Ciencia do Solo2028314.159440.510(Q2)Brazil000244(1)9(19)
Agricultural Wastes1929015,267001(19)00
Agriculture Ecosystems And Environment1956029,47121511.54 (Q1)Netherlands0015(3)30(4)28(12)
Journal Of Analytical And Applied Pyrolysis19114460,21131151.11 (Q1)Netherlands000191(1)13(18)
Journal Of Soil And Water Conservation1827915,509660.73(Q1)United States01(6)095(2)44(10)
Applied Biochemistry And Biotechnology1746827,5312970.61 (Q2)United States0028(2)125(1)22(14)
A: number of articles; R: rank position by number of articles; TC: number of citations for all articles; TC/A: number of citations by article; Hi(A): H index articles; Hi(J): H index journal; SJR: Scimago Journal Rank (quartile); C: country.
In the third period (1980–1992) 135 journals were counted. In the fourth period (1993–2005) the increase was almost doubled, 269 journals published 607 articles in that period. In the last period, from 2006 to 2018, 742 journals published the 2148 articles produced, which was 74% of the total number of journals. 45% of the journals belong to the Netherlands, 30% to the United States and only 5% of the journals come from South America. 65% of the journals come from Europe.
A high percentage of the journals (83%) belong to the Q1 quartile, according to 2018 SCImago Journal Rank (SJR) indicators. Only four of the main journals belong to the second and third quartiles. The first article of the sample analysed was published in the journal “The Journal of Agricultural Science”, whose specialty is Agricultural and Biological Sciences, Agronomy and Crop Sciences. This journal only accumulates a total of four published articles during the whole analysed period. The most recent article of the sample (December 2018), was published in the journal Current Science, whose subject category is multidisciplinary. This journal accumulates five articles of the total sample.
The “Bioresource Technology” journal has published the highest number of articles (98), which represents 3% of the total sample and places it in first position within the ranking. Furthermore, this journal has the highest number of total citations (6,643), and it appeared for the first time in the third period (1980–1992) in the 17th position in the journal list. It increased from three to 25 articles in the fourth period (1993–2005) and published 70 in the last period (2006–2018), therefore, it occupied the first position of the list in those last two periods. The first article of this journal, dated 1991, only has one associated citation (Gibbons etal., 1991).
The second journal with the highest number of articles (48) is “Soil Science Society of America Journal”, which specialises in Agricultural, Biological and Soil Sciences. This journal has a total of 2670 citations and an H index of 147. Biomass and Bioenergy Journal, with 47 documents (3032 citations), is placed in third position in the ranking. This journal, with an H index of 156, has Agricultural, Biological and Soil Sciences among its main subject categories. This journal has a total of 2670 citations and a H index of 147. Biomass and Bioenergy journal, with 47 documents (3032 citations), is placed in third position in the ranking. This journal with an H index of 156, has among its main subject categories: Agricultural and Biological Sciences, Agronomy and Crop Sciences, Renewable Energy, Sustainability and Environment and Waste Management and Elimination. The article with the highest number of citations of all the sample analysed, dated from 2004, was published in this journal (1137 citations).
The Journal of Hazardous Materials, which has 28 documents published on this issue, has the second total highest number of citations (3,933) and an average of 140.46 citations per document - the highest in the list. Among the main areas and subject categories of this journal, we find Environmental Sciences and Waste Management and Elimination. 23% of the total number of articles published on agricultural waste were published in these 25 journals.
The number of journals, as well as their evolution throughout the different periods confirms the growing importance of this issue for researchers and institutions, and also draws attention to the representatives and/or responsible persons in the media through which these articles are visualised and diffused. Good interaction and communication between scientists and society is an important support tool for research. For more than 4 decades, journals have been an important indicator for impact assessments of research studies, which are mainly considered through the number of citations (Garfield, 1979, 1998).
It is also important to highlight that journals in recent years have passed from having a specialised approach in one or few disciplines to a wider framework, which is multidisciplinary and gives more opportunities for dissemination within the scientific community (Ackerson and Chapman, 2003). In fact, one of the 27 subject categories of Scopus are “General Matter” which includes multidisciplinary journals. This is also visible in the wide range of specific subject categories in which the journals are grouped, which has increased over the last years, from 295 in 2012 to 313 in 2018 (SJR, 2019).
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https://www.sciencedirect.com/science/article/pii/S2351989419307516
## ¿What is the new about food packaging material? A bibliometric review during 1996–2016
Adriana Rodríguez-Rojas, ... Ronald Arana-Florez, in , 2019
### 3.1.3 Academic discipline
In line with Scopus, studies contributed to this research topic involved in 13 different academic disciplines (Fig. 2). Agricultural and Biological Sciences is ranked as the No. 1 FPM-related discipline, with the highest percentage (51%) followed by Materials Science (11%) and Chemistry Engineering (9%). Publications involved in Computer science, Business, Management and Accounting fields, Energy, Physics and Astronomy field, and Immunology and Microbiology discipline also contributed to the development of FPM related studies, with 2% and 1% of the total studied publications.
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URL:
https://www.sciencedirect.com/science/article/pii/S0924224418306733
## Multiple values and knowledge integration in indigenous coastal and marine social-ecological systems research: A systematic review
Rodolfo Dam Lam, ... Taira Stanley, in Ecosystem Services, 2019
### 3.3 Transdisciplinarity
There is an increasing trend towards a broader representation and collaboration between academic disciplines and fields in studies related to coastal/marine SES in indigenous settings (Fig. 3). Initially studies came from just a few fields within the environmental, agricultural, and biological sciences such as oceanography, environmental sciences, and management and policy studies. Currently studies come from a plethora of different academic disciplines and fields through academic fields such as computer sciences, economics, biochemistry, arts and humanities, and pharmacology, among others (see Table S8, Supplementary Electronic Material).
Fig. 4 outlines the types of institutions engaged in this type of research and presents in detail the authors’ cross-collaboration within (and between) institutions. In a sense Fig. 4 provides a snapshot of the stakeholders directly involved in the conceptualisation, design, and execution of the reviewed studies. Distinct patterns emerge when comparing between research classes. Most contextual research studies are predominately produced within academia compared to other types of institutions. Most of the collaborations tend to be between academic institutions from different countries (Fig. 4), and only in a few studies are indigenous community members integrated actively in the research team (McMillan and Prosper, 2016; Roberts et al., 2016; Suluk and Blakney, 2009). In contrast, authors from causal research studies tend to be more open to collaborations with multiple non-academic institutions such as research institutes and indigenous group agencies (e.g. traditional institutions in charge of local marine resource management) (Butler et al., 2013; Fuentes et al., 2015; Gratani et al., 2011). However, interestingly, there seems to be less collaboration with actual indigenous community members within causal research studies, compared to contextual research studies.
The level of stakeholders’ integration also varies between research classes. Despite a lack of causal research studies in the early 2000s (we found only 1 study from 1998), they tend to integrate more stakeholders (and at a higher proportion of studies) compared to contextual research (Fig. 5). Furthermore, even though indigenous communities are the most frequently integrated stakeholders in both classes, there seems to be a different level of contribution to the actual research. Causal research studies tend to integrate more meaningfully the input of indigenous people than contextual research. Higher integration of indigenous communities through co-design approaches is observed in the causal research class (10% of all studies) rather than the contextual research class (5% of all studies). This also applies for general public participation through co-design, discussions and consultations (see Table S4, Supplementary Electronic Material, in “Indigenous People Integration”).
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https://www.sciencedirect.com/science/article/pii/S2212041618305151
## Stewardship as a boundary object for sustainability research: Linking care, knowledge and agency
Johan Peçanha Enqvist, ... Maria Tengö, in Landscape and Urban Planning, 2018
### Appendix B Identifying records for literature review
The literature review conducted in this study used records identified through a search in the online database Scopus, on 20th March, 2017, accessed through Stockholm University. Relevant records were identified through five steps (Fig. B1).
Step 1: Records identified through Scopus search for ‘stewardship’
We applied the following search protocol:
“Stewardship” in [Article Title] OR “Stewardship” in [Keywords].
Published 1990–2016.
Document type: Article or Review.
Step 2: Records’ subject areas screened for relevance
The search result was restricted to the following subject areas:
Environmental science; social sciences; agricultural and biological sciences; business, management and accounting; economics, econometrics and finance; arts and humanities; earth and planetary sciences; materials science; decision sciences; multidisciplinary.
The following subject areas were excluded:
Medicine; pharmacology, toxicology and pharmaceutics; engineering; immunology and microbiology; biochemistry, genetics and molecular biology; nursing; energy; chemical engineering; health professions; computer science; chemistry; psychology; veterinary; physics and astronomy; mathematics; neuroscience; dentistry; undefined.
This exclusion step uses a function that relies on Scopus’ classification of the articles themselves. This classification is currently not directly accessible to users, neither when viewing a specific article entry, nor when exporting the aggregate list of search hits. As described in the main text, our study instead analyzes articles based on what Subject Area its journal is assigned (see Fig. 2 in the main text). A consequence of this is that there is a small number of articles in our study that, because of the journals where they are published, are classifieds in fields like Medicine – even though this subject was excluded in the initial search. To ensure environmental relevance of the specific article, we therefore also carried out Step3.
Step 3: Records screened for ‘environmental’ relevance
We screened the remaining 1524 records based on a conventional understanding of ‘environment’ from the Online Oxford Dictionary: “the natural world, as a whole or in a particular geographical area, especially as affected by human activity” (https://en.oxforddictionaries.com/definition/environment). We deliberately adopted a rather conservative definition of ‘environment’ to limit our sample and maintain conceptual coherence.
In order to identify articles of environmental relevance, we specified this definition with keywords:
Environment in general: environment, ecosystem, ecology, nature, sustainability, conservation, green, biodiversity
Settings: landscape, land, planet, biosphere, marine, grassland, wilderness, ocean
Resources: fishing, timber, water (including watersheds, groundwater, wells, lakes) game, tree, farm, livestock, crops, wildlife, animal, aquaculture, pests/pesticides, insects/insecticides, soil
Issues/Problems: Climate Change (including ice melting and thinning), recycling (Note: not ‘waste’ in general), species loss/extinctions
We first searched for environmental relevance in the titles of the records. If the keywords were absent or environmental relevance unclear in the title, we then searched in the abstract. If the keywords were absent in the abstract and the article was clearly not of environmental relevance, we excluded the record. If the environmental relevance was still unclear, we retrieved the full-text PDF for the record and searched there. If still unclear, we interpreted the environmental relevance based on our perception of the underlying ‘intent’ of the article.
Step 4: Screened for duplicates
At this stage, the remaining 1093 records were imported from Scopus into a reference management software, Mendeley (version 1.17.9). Using the automatic inbuilt function in Mendeley, four sets of duplicates were identified and removed. Furthermore, two sets of duplicates were identified manually by visually scanning and comparing the records.
Step 5: Removal of records with no abstract.
The records were checked manually to ensure that all had abstract information. Any records without abstract information were removed. This left a total of 1002 records that were all included in the study.
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URL:
https://www.sciencedirect.com/science/article/pii/S0169204618305966
## Flavonoids, anthocyanins, betalains, curcumin, and carotenoids: Sources, classification and enhanced stabilization by encapsulation and adsorption
Betina Luiza Koop, ... Alcilene Rodrigues Monteiro, in Food Research International, 2022
### 2.6 Stabilization methods of the bioactive compounds
The Scopus Database (www.scopus.com) was used to identify the scientific methods that have been used for stabilization flavonoids, anthocyanins, betalains, curcumin, and carotenoids. Encapsulation and adsorption were the main stabilization methods found in scientific documents currently published into areas of knowledge such as Agricultural and Biological Sciences, Biochemistry, Genetics, and Molecular Biology, Pharmacology, Toxicology and Pharmaceutics, Chemistry, Medicine, Chemical Engineering, Immunology and Microbiology, Environmental Science, and Material Science. The countries that most researched on bioactive compounds were: China (30%), India (15%), the United States (15%), and Brazil (10%). From 2016 to 2020, 155.46 researches were found with the keyword bioactive compounds, from 79% were research articles, 14% reviews, 4% book chapters, and 3% conference paper, notes, among others. In addition, 27.18 patents were deposited, from 72.54% were registered in the United States Patent & Trademark Office, 11.98% in European Patent Office, 10.30% in Japan Patent Office, 4.92% in World Intellectual Property Organization, and 0.26% in the United Kingdom Intellectual Property Office.
According to Fig. 2-a, the number of scientific documents about bioactive compounds has been significantly increased in the last years. It was possible to observe a growth trend in research involving bioactive compounds being 31% for flavonoids, 28% for curcumin, 22% for carotenoids, 17% for anthocyanins, and 1% betalains. Curcumin was the bioactive compound most studied in 2020. According to Scopus Database, researches on bioactive compound stabilization techniques corresponds to only 3.85%. Fig. 2-b shows the published scientific documents on bioactive compounds and their stabilization methods.
Among stabilization techniques, data on encapsulation were equivalent to 63.5%, whereas adsorption was 36.5%. Curcumin was the most studied bioactive compound, 54.7%, followed by anthocyanins 16%, flavonoids 14.5%, carotenoids 13.2%, and betalains 1.6%.
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URL:
https://www.sciencedirect.com/science/article/pii/S0963996921008292
## Miscanthus in the European bio-economy: A network analysis
N. Ben Fradj, ... M. Matyka, in Industrial Crops and Products, 2020
### 2.1 Identification of the most relevant references
In the literature, miscanthus has been referred to in different ways. The only hybrid genotype commercially available in Europe is Miscanthus$×$giganteus. Nevertheless, different genotypes have been tested to optimise biomass potential, i.e. Miscanthus sinensis, Miscanthus sacchariflorus and other hybrids. Then, the bibliographic search was arranged and limited to the following terms: “Miscanthus$×$giganteus”, “Miscanthus sinensis”, “Miscanthus sacchariflorus” and “Miscanthus hybrids”. The references are provided by Scopus database linked to the most important publishers, such as Elsevier, Springer, and Blackwell, among others.
The query search had resulted in 2985 papers. The search was then restricted to 12 (out of 25) Scopus’ subject areas: “agricultural and biological sciences”, “environmental science”, “energy”, “chemical engineering”, “biochemistry”, “materials science”, “social sciences”, “computer sciences”, “multidisciplinary”, “business, management and accounting”, “mathematics”, “economics, econometrics and Finance”, and “decision science”. The search was limited to English and included only journal articles, book chapters, books and conference proceedings. However, no restriction has been put on the year of publication.
Given that the bibliographic search had generated a large number of studies (2239 papers), a GUI screener from METAGEAR package for R (Lajeunesse, 2017), was used to screen the abstracts and titles, thus selecting the most relevant references. After the screening, data were extracted from 1967 selected studies, first, to carry out a network analysis, and second, to analyse funding orientation in Europe (Fig. 1).
The majority of selected references are mainly published in a wide range of journals (94.2%). Conference proceedings and book chapters account for only 4.2% and 1.6%, respectively. The journals’ scopes extend to different aspects including management, environment, socio-economics, policy, bioenergy process and utilisation, and breeding (Fig. 2). Most of the papers are published in GCB Bioenergy (10.1%), Biomass & Bioenergy (8.3%), Bioresources technology (5.9%), and Industrial Crops and Products (3.3%).
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https://www.sciencedirect.com/science/article/pii/S0926669020301977
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https://www.science.gov/topicpages/0-9/2011-10-01+false+separate.html | #### Sample records for 2011-10-01 false separate
1. 47 CFR 22.703 - Separate rural subscriber station authorization not required.
Code of Federal Regulations, 2011 CFR
2011-10-01
... or base station from which they receive service. ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Separate rural subscriber station authorization... subscriber station authorization not required. A separate authorization is not required for rural...
2. 47 CFR 73.807 - Minimum distance separation between stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Minimum distance separation between stations... separation between stations. Minimum separation requirements for LP100 and LP10 stations, as defined in §§ 73... these separations are met. Minimum distances for co-channel and first-adjacent channel are...
3. 49 CFR 1242.06 - Instructions for separation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Instructions for separation. 1242.06 Section 1242... BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON... Instructions for separation. (a) Certain instructions for separating common expense accounts...
4. 47 CFR 73.507 - Minimum distance separations between stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Minimum distance separations between stations... separations between stations. (a) Minimum distance separations. No application for a new station, or change in... proposed facilities will be located so as to meet the adjacent channel distance separations specified...
5. 46 CFR 162.050-21 - Separator: Design specification.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 6 2011-10-01 2011-10-01 false Separator: Design specification. 162.050-21 Section 162... Separator: Design specification. (a) A separator must be designed to operate in each plane that forms an.... (c) Each separator component that is a moving part must be designed so that its movement...
6. 47 CFR 73.207 - Minimum distance separation between stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Minimum distance separation between stations... SERVICES RADIO BROADCAST SERVICES FM Broadcast Stations § 73.207 Minimum distance separation between... reference points meet all of the minimum distance separation requirements of this section. The...
7. 47 CFR 73.610 - Minimum distance separations between stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Minimum distance separations between stations... SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.610 Minimum distance separations between stations. (a) The provisions of this section relate to allotment separations and...
8. 49 CFR 1242.00 - Separation of common operating expenses.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Separation of common operating expenses. 1242.00... TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON....00 Separation of common operating expenses. (a) Commencing with annual reports for the year 1978...
9. 47 CFR 24.134 - Co-channel separation criteria.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Co-channel separation criteria. 24.134 Section... PERSONAL COMMUNICATIONS SERVICES Narrowband PCS § 24.134 Co-channel separation criteria. The minimum co-channel separation distance between base stations in different service areas is 113 kilometers (70...
10. 46 CFR 502.224 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 9 2011-10-01 2011-10-01 false Separation of functions. 502.224 Section 502.224 Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS RULES OF PRACTICE AND PROCEDURE Briefs; Requests for Findings; Decisions; Exceptions § 502.224 Separation of functions. The separation...
11. 46 CFR 201.134 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false Separation of functions. 201.134 Section 201.134 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION POLICY, PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Hearing Procedures (Rule 13) § 201.134 Separation of functions. The separation...
12. 47 CFR 76.612 - Cable television frequency separation standards.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Cable television frequency separation standards... frequency separation standards. All cable television systems which operate in the frequency bands 108-137 and 225-400 MHz shall comply with the following frequency separation standards: (a) In...
13. 49 CFR 386.3 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 5 2011-10-01 2011-10-01 false Separation of functions. 386.3 Section 386.3 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... Scope of Rules; Definitions and General Provisions § 386.3 Separation of functions. (a) Civil...
14. 49 CFR 31.14 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 1 2011-10-01 2011-10-01 false Separation of functions. 31.14 Section 31.14 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.14 Separation of functions. (a) The investigating official, the reviewing official, and any employee or agent of...
15. 45 CFR 79.14 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 1 2011-10-01 2011-10-01 false Separation of functions. 79.14 Section 79.14 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.14 Separation of functions. (a) The investigating official, the reviewing official, and...
16. 49 CFR 1503.603 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Separation of functions. 1503.603 Section 1503.603 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION... Rules of Practice in TSA Civil Penalty Actions § 1503.603 Separation of functions. (a) Civil...
17. 49 CFR 604.35 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 7 2011-10-01 2011-10-01 false Separation of functions. 604.35 Section 604.35 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION...) § 604.35 Separation of functions. (a) Proceedings under this part shall be handled by an FTA...
18. 43 CFR 35.14 - Separation of functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Separation of functions. 35.14 Section 35.14 Public Lands: Interior Office of the Secretary of the Interior ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS AND STATEMENTS § 35.14 Separation of functions. (a) The investigating official,...
19. 46 CFR 153.292 - Separation of piping systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Separation of piping systems. 153.292 Section 153.292 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS... Systems and Cargo Handling Equipment § 153.292 Separation of piping systems. Cargo piping systems must...
20. 49 CFR 1503.613 - Consolidation and separation of cases.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Consolidation and separation of cases. 1503.613 Section 1503.613 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION... separation of cases. (a) Consolidation. If two or more actions involve common questions of law or fact,...
1. 50 CFR 654.24 - Shrimp/stone crab separation zones.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Shrimp/stone crab separation zones. 654... Measures § 654.24 Shrimp/stone crab separation zones. Five zones are established in the management area and Florida's waters off Citrus and Hernando Counties for the separation of shrimp trawling and stone...
2. 50 CFR 452.07 - Separation of functions and ex parte communications.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Separation of functions and ex parte... SPECIES EXEMPTION PROCESS CONSIDERATION OF APPLICATION BY THE SECRETARY § 452.07 Separation of functions and ex parte communications. (a) Separation of functions. (1) The Administrative Law Judge and...
3. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 2 2011-10-01 2011-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...
4. 45 CFR 302.20 - Separation of cash handling and accounting functions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 2 2011-10-01 2011-10-01 false Separation of cash handling and accounting functions. 302.20 Section 302.20 Public Welfare Regulations Relating to Public Welfare OFFICE OF CHILD..., DEPARTMENT OF HEALTH AND HUMAN SERVICES STATE PLAN REQUIREMENTS § 302.20 Separation of cash handling...
5. 42 CFR 457.340 - Application for and enrollment in a separate child health program.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 4 2011-10-01 2011-10-01 false Application for and enrollment in a separate child health program. 457.340 Section 457.340 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STATE CHILDREN'S HEALTH INSURANCE PROGRAMS...
6. 46 CFR 108.137 - Bulkhead and deck separations of accommodation spaces.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Bulkhead and deck separations of accommodation spaces. 108.137 Section 108.137 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Structural Fire Protection §...
7. 42 CFR 61.14 - Separate consideration of information concerning moral character or loyalty.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false Separate consideration of information concerning moral character or loyalty. 61.14 Section 61.14 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships §...
8. 48 CFR 52.222-30 - Davis-Bacon Act-Price Adjustment (None or Separately Specified Method).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Davis-Bacon Act-Price... CLAUSES Text of Provisions and Clauses 52.222-30 Davis-Bacon Act—Price Adjustment (None or Separately Specified Method). As prescribed in 22.407(e), insert the following clause: Davis-Bacon Act—Price...
9. 42 CFR 21.23 - False statements as disqualification.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...
10. Panic, Suffocation False Alarms, Separation Anxiety and Endogenous Opioids
PubMed Central
Preter, Maurice; Klein, Donald F.
2008-01-01
This review paper presents an amplification of the suffocation false alarm theory (SFA) of spontaneous panic (Klein, 1993). SFA postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. That panic is distinct from Cannon’s emergency fear response and Selye’s General Alarm Syndrome is shown by the prominence of intense air hunger during these attacks. Further, panic sufferers have chronic sighing abnormalities outside of the acute attack. Another basic physiologic distinction between fear and panic is the counter-intuitive lack of hypothalamic-pituitary-adrenal (HPA) activation in panic. Understanding panic as provoked by indicators of potential suffocation, such as fluctuations in pCO2 and brain lactate, as well as environmental circumstances fits the observed respiratory abnormalities. However, that sudden loss, bereavement and childhood separation anxiety are also antecedents of “spontaneous” panic requires an integrative explanation. Because of the opioid system’s central regulatory role in both disordered breathing and separation distress, we detail the role of opioidergic dysfunction in decreasing the suffocation alarm threshold. We present results from our laboratory where the naloxone-lactate challenge in normals produces supportive evidence for the endorphinergic defect hypothesis in the form of a distress episode of specific tidal volume hyperventilation paralleling challenge-produced and clinical panic. PMID:17765379
11. 45 CFR 3.4 - False reports and reports of injury or damage.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 1 2011-10-01 2011-10-01 false False reports and reports of injury or damage. 3.4 Section 3.4 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CONDUCT OF PERSONS AND TRAFFIC ON THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE General § 3.4 False reports...
12. 47 CFR 11.45 - Prohibition of false or deceptive EAS transmissions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Prohibition of false or deceptive EAS transmissions. 11.45 Section 11.45 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Organization § 11.45 Prohibition of false or deceptive EAS transmissions. No person...
13. 47 CFR 0.560 - Penalty for false representation of identity.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Penalty for false representation of identity. 0.560 Section 0.560 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMISSION ORGANIZATION Privacy Act Regulations § 0.560 Penalty for false representation of identity. Any individual who...
14. 43 CFR 20.510 - Fraud or false statements in a Government matter.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Fraud or false statements in a Government matter. 20.510 Section 20.510 Public Lands: Interior Office of the Secretary of the Interior EMPLOYEE RESPONSIBILITIES AND CONDUCT Other Employee Conduct Provisions § 20.510 Fraud or false statements in a...
15. 47 CFR 80.335 - Procedures for canceling false distress alerts.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Procedures for canceling false distress alerts. 80.335 Section 80.335 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures...
16. 49 CFR 1570.13 - False statements regarding security background checks by public transportation agency or railroad...
Code of Federal Regulations, 2011 CFR
2011-10-01
... Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY MARITIME AND LAND TRANSPORTATION SECURITY GENERAL RULES § 1570.13 False statements... 49 Transportation 9 2011-10-01 2011-10-01 false False statements regarding security...
17. Ordering Power of Separate versus Grouped True-False Tests: Interaction of Type of Test with Knowledge Levels of Examinees.
ERIC Educational Resources Information Center
Hsu, Louis M.
1979-01-01
A comparison of the relative ordering power of separate and grouped-items true-false tests indicated that neither type of test was uniformly superior to the other across all levels of knowledge of examinees. Grouped-item tests were found superior for examinees with low levels of knowledge. (Author/CTM)
18. Lifelong opioidergic vulnerability through early life separation: a recent extension of the false suffocation alarm theory of panic disorder.
PubMed
Preter, Maurice; Klein, Donald F
2014-10-01
The present paper is the edited version of our presentations at the "First World Symposium On Translational Models Of Panic Disorder", in Vitoria, E.S., Brazil, on November 16-18, 2012. We also review relevant work that appeared after the conference. Suffocation-False Alarm Theory (Klein, 1993) postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. The expanded Suffocation-False Alarm Theory (Preter and Klein, 2008) hypothesizes that endogenous opioidergic dysregulation may underlie the respiratory pathophysiology and suffocation sensitivity in panic disorder. Opioidergic dysregulation increases sensitivity to CO2, separation distress and panic attacks. That sudden loss, bereavement and childhood separation anxiety are also antecedents of "spontaneous" panic requires an integrative explanation. Our work unveiling the lifelong endogenous opioid system impairing effects of childhood parental loss (CPL) and parental separation in non-ill, normal adults opens a new experimental, investigatory area.
19. 43 CFR 35.14 - Separation of functions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Separation of functions. 35.14 Section 35.14 Public Lands: Interior Office of the Secretary of the Interior ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS AND STATEMENTS § 35.14 Separation of functions. (a) The investigating official,...
20. What about False Insights? Deconstructing the Aha! Experience along Its Multiple Dimensions for Correct and Incorrect Solutions Separately.
PubMed
Danek, Amory H; Wiley, Jennifer
2016-01-01
The subjective Aha! experience that problem solvers often report when they find a solution has been taken as a marker for insight. If Aha! is closely linked to insightful solution processes, then theoretically, an Aha! should only be experienced when the correct solution is found. However, little work has explored whether the Aha! experience can also accompany incorrect solutions ("false insights"). Similarly, although the Aha! experience is not a unitary construct, little work has explored the different dimensions that have been proposed as its constituents. To address these gaps in the literature, 70 participants were presented with a set of difficult problems (37 magic tricks), and rated each of their solutions for Aha! as well as with regard to Suddenness in the emergence of the solution, Certainty of being correct, Surprise, Pleasure, Relief, and Drive. Solution times were also used as predictors for the Aha!
1. What about False Insights? Deconstructing the Aha! Experience along Its Multiple Dimensions for Correct and Incorrect Solutions Separately
PubMed Central
Danek, Amory H.; Wiley, Jennifer
2017-01-01
The subjective Aha! experience that problem solvers often report when they find a solution has been taken as a marker for insight. If Aha! is closely linked to insightful solution processes, then theoretically, an Aha! should only be experienced when the correct solution is found. However, little work has explored whether the Aha! experience can also accompany incorrect solutions (“false insights”). Similarly, although the Aha! experience is not a unitary construct, little work has explored the different dimensions that have been proposed as its constituents. To address these gaps in the literature, 70 participants were presented with a set of difficult problems (37 magic tricks), and rated each of their solutions for Aha! as well as with regard to Suddenness in the emergence of the solution, Certainty of being correct, Surprise, Pleasure, Relief, and Drive. Solution times were also used as predictors for the Aha! experience. This study reports three main findings: First, false insights exist. Second, the Aha! experience is multidimensional and consists of the key components Pleasure, Suddenness and Certainty. Third, although Aha! experiences for correct and incorrect solutions share these three common dimensions, they are also experienced differently with regard to magnitude and quality, with correct solutions emerging faster, leading to stronger Aha! experiences, and higher ratings of Pleasure, Suddenness, and Certainty. Solution correctness proffered a slightly different emotional coloring to the Aha! experience, with the additional perception of Relief for correct solutions, and Surprise for incorrect ones. These results cast some doubt on the assumption that the occurrence of an Aha! experience can serve as a definitive signal that a true insight has taken place. On the other hand, the quantitative and qualitative differences in the experience of correct and incorrect solutions demonstrate that the Aha! experience is not a mere epiphenomenon. Strong Aha
2. 48 CFR 236.604 - Performance evaluation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Performance evaluation... Architect-Engineer Services 236.604 Performance evaluation. Prepare a separate performance evaluation after... familiar with the architect-engineer contractor's performance....
3. Preparative Separation of Main Ustilaginoidins from Rice False Smut Balls by High-Speed Counter-Current Chromatography
PubMed Central
Sun, Weibo; Dong, Xuejiao; Xu, Dan; Meng, Jiajia; Fu, Xiaoxiang; Wang, Xiaohan; Lai, Daowan; Zhou, Ligang; Liu, Yang
2016-01-01
Ustilaginoidins are bis-naphtho-γ-pyrone mycotoxins isolated from the rice false smut balls (FSBs) infected by the pathogen Villosiclava virens in rice spikelets on panicles. In order to obtain large amounts of pure ustilaginoidins to further evaluate their biological activities and functions, phytotoxicity on rice, security to human and animals as well as to accelerate their applications as pharmaceuticals, preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of seven bis-naphtho-γ-pyrone mycotoxins, namely ustilaginoidins A (1), G (2), B (3), H (4), I (5), C (6), and J (7) from the ethyl acetate crude extract of rice FSBs. Both 1 and 2 were prepared by HSCCC from the low-polarity fraction of the crude extract using the two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at the volume ratio of 6.5:3.5:5.0:5.0. Similarly, 3, 4 and 5 were prepared from the medium-polarity fraction using the system at the volume ratio of 4.0:5.0:5.0:6.0, and 6 and 7 were prepared from the higher-polarity fraction using the system at volume ratio of 3.0:5.0:4.0:6.7. A total of 6.2 mg of 1, 5.1 mg of 2, 3.9 mg of 3, 1.2 mg of 4, 5.7 mg of 5, 3.5 mg of 6, and 6.1 mg of 7 with purities of 88%, 82%, 91%, 80%, 92%, 81% and 83%, respectively, were yielded from total 62 mg fraction samples in three independent HSCCC runs. The structures of the purified ustilaginoidins were characterized by means of physicochemical and spectrometric analysis. PMID:26771638
4. False assumptions.
PubMed
Swaminathan, M
1997-01-01
Indian women do not have to be told the benefits of breast feeding or "rescued from the clutches of wicked multinational companies" by international agencies. There is no proof that breast feeding has declined in India; in fact, a 1987 survey revealed that 98% of Indian women breast feed. Efforts to promote breast feeding among the middle classes rely on such initiatives as the "baby friendly" hospital where breast feeding is promoted immediately after birth. This ignores the 76% of Indian women who give birth at home. Blaming this unproved decline in breast feeding on multinational companies distracts attention from more far-reaching and intractable effects of social change. While the Infant Milk Substitutes Act is helpful, it also deflects attention from more pressing issues. Another false assumption is that Indian women are abandoning breast feeding to comply with the demands of employment, but research indicates that most women give up employment for breast feeding, despite the economic cost to their families. Women also seek work in the informal sector to secure the flexibility to meet their child care responsibilities. Instead of being concerned about "teaching" women what they already know about the benefits of breast feeding, efforts should be made to remove the constraints women face as a result of their multiple roles and to empower them with the support of families, governmental policies and legislation, employers, health professionals, and the media.
5. 47 CFR Parts 37-39 - [RESERVED
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 37 PARTS 37-39 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES JURISDICTIONAL SEPARATIONS PROCEDURES; STANDARD PROCEDURES FOR SEPARATING TELECOMMUNICATIONS PROPERTY COSTS, REVENUES, EXPENSES, TAXES AND RESERVES FOR TELECOMMUNICATIONS COMPANIES...
6. 47 CFR 36.382 - Category 3-All other customer services expense.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Category 3-All other customer services expense... Expenses and Taxes Customer Operations Expenses § 36.382 Category 3—All other customer services expense. (a... SERVICES JURISDICTIONAL SEPARATIONS PROCEDURES; STANDARD PROCEDURES FOR SEPARATING...
7. 49 CFR 1242.85 - Fringe benefits (account 12-63-00).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Fringe benefits (account 12-63-00). 1242.85....85 Fringe benefits (account 12-63-00). Separate the common expenses in proportion to the total common salaries and wages expense separation (account 11-XX-XX) determined in §§ 1242.83 and 1242.84....
8. 46 CFR 32.52-5 - Bilge piping for pump rooms and adjacent cofferdams on tank vessels constructed or converted on...
Code of Federal Regulations, 2011 CFR
2011-10-01
... REQUIREMENTS Bilge Systems § 32.52-5 Bilge piping for pump rooms and adjacent cofferdams on tank vessels... 46 Shipping 1 2011-10-01 2011-10-01 false Bilge piping for pump rooms and adjacent cofferdams on... drainage from the pumproom bilges and adjacent cofferdams. A separate bilge pump, ejector, or bilge...
9. 42 CFR 102.45 - Multiple survivors.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false Multiple survivors. 102.45 Section 102.45 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES VACCINES SMALLPOX COMPENSATION... smallpox vaccine recipient or vaccinia contact may file Request Forms separately or together....
10. 46 CFR 92.20-20 - Sleeping accommodations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Sleeping accommodations. 92.20-20 Section 92.20-20... CONSTRUCTION AND ARRANGEMENT Accommodations for Officers and Crew § 92.20-20 Sleeping accommodations. (a) Where practicable, each licensed officer must be provided with a separate stateroom. (b) Sleeping accommodations...
11. 46 CFR 32.40-20 - Sleeping accommodations-T/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Sleeping accommodations-T/ALL. 32.40-20 Section 32.40-20... REQUIREMENTS Accommodations for Officers and Crew § 32.40-20 Sleeping accommodations—T/ALL. (a) Where practicable, each licensed officer shall be provided with a separate stateroom. (b) Sleeping...
12. 46 CFR 72.20-20 - Sleeping accommodations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false Sleeping accommodations. 72.20-20 Section 72.20-20... ARRANGEMENT Accommodations for Officers and Crew § 72.20-20 Sleeping accommodations. (a) Where practicable, each licensed officer shall be provided with a separate stateroom. (b) Sleeping accommodations for...
13. 47 CFR 61.22 - Composition of tariffs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... numbered in a series separate from non-contract-based tariffs. Numbers must be in the form of “CT No... 47 Telecommunication 3 2011-10-01 2011-10-01 false Composition of tariffs. 61.22 Section 61.22 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS...
14. 46 CFR 162.050-37 - Vibration test.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 6 2011-10-01 2011-10-01 false Vibration test. 162.050-37 Section 162.050-37 Shipping...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment § 162.050-37 Vibration test. (a... and each control of a separator must be subjected to continuous sinusoidal vibration in each of...
15. 47 CFR 15.32 - Test procedures for CPU boards and computer power supplies.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Test procedures for CPU boards and computer... FREQUENCY DEVICES General § 15.32 Test procedures for CPU boards and computer power supplies. Power supplies and CPU boards used with personal computers and for which separate authorizations are required to...
16. 44 CFR 19.520 - Job classification and structure.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Job classification and... Education Programs or Activities Prohibited § 19.520 Job classification and structure. A recipient shall not: (a) Classify a job as being for males or for females; (b) Maintain or establish separate lines...
17. 49 CFR 178.358-3 - Modification of Specification 21PF-1 overpacks.
Code of Federal Regulations, 2011 CFR
2011-10-01
... S1E-31536-J1-D of CAPE-1662, Revision 1, Supplement 1, for locations. (2) Weigh each packaging element (top and bottom halves) separately to an accuracy of ±2.3 kg (±5 pounds) and record the weights. If... 49 Transportation 3 2011-10-01 2011-10-01 false Modification of Specification 21PF-1...
18. 47 CFR 36.302 - General.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false General. 36.302 Section 36.302 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES JURISDICTIONAL SEPARATIONS... expense accounts are segregated in the accounting process among the following subsidiary record...
19. 46 CFR 403.110 - Accounting entities.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false Accounting entities. 403.110 Section 403.110 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE UNIFORM ACCOUNTING SYSTEM General § 403.110 Accounting entities. Each Association shall be a separate...
20. 46 CFR 129.395 - Radio installations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Radio installations. 129.395 Section 129.395 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.395 Radio installations. A separate circuit, with overcurrent protection at the switchboard, must be provided for at least one radio installation....
1. 43 CFR 3592.3 - Production maps.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Production maps. 3592.3 Section 3592.3... OPERATIONS Plans and Maps § 3592.3 Production maps. (a) The operator shall prepare maps which show mineral production from the leased lands. All excavations in each separate bed or deposit shall be shown in such...
2. 50 CFR 1.1 - Meaning of terms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Meaning of terms. 1.1 Section 1.1 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS § 1.1 Meaning of terms. As used in this chapter, unless separately defined, terms shall have...
3. 46 CFR Section 1 - Books of account.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false Books of account. Section 1 Section 1 Shipping MARITIME... TRANSACTIONS UNDER AGENCY AGREEMENTS Accounts Section 1 Books of account. A separate set of books of account... agreement. The books of original entry and ledgers may be similar in design to those heretofore employed...
4. 47 CFR 69.157 - Line port costs in excess of basic, analog service.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 3 2011-10-01 2011-10-01 false Line port costs in excess of basic, analog... § 69.157 Line port costs in excess of basic, analog service. To the extent that the costs of ISDN line..., analog service, local exchange carriers may recover the difference through a separate monthly...
5. 46 CFR 56.50-30 - Boiler feed piping.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 2 2011-10-01 2011-10-01 false Boiler feed piping. 56.50-30 Section 56.50-30 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-30 Boiler feed piping. (a) General... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted...
6. 45 CFR 617.11 - Investigation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 3 2011-10-01 2011-10-01 false Investigation. 617.11 Section 617.11 Public....11 Investigation. (a) Informal investigation. (1) NSF will investigate complaints that are unresolved... initial investigation, NSF will use informal fact finding methods, including joint or separate...
7. 45 CFR 708.10 - Procedures for salary offset.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 3 2011-10-01 2011-10-01 false Procedures for salary offset. 708.10 Section 708... COLLECTION BY SALARY OFFSET FROM INDEBTED CURRENT AND FORMER EMPLOYEES § 708.10 Procedures for salary offset... to final salary payment, retired pay, or lump sum leave, etc. as of the date of separation to...
8. 46 CFR 196.34-15 - Shipboard stowage.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Shipboard stowage. 196.34-15 Section 196.34-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Work Vests § 196.34-15 Shipboard stowage. (a) The approved buoyant work vests shall be stowed separately...
9. 47 CFR 36.378 - Category 2-Customer services (revenue accounting).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Category 2-Customer services (revenue... Operating Expenses and Taxes Customer Operations Expenses § 36.378 Category 2—Customer services (revenue... CARRIER SERVICES JURISDICTIONAL SEPARATIONS PROCEDURES; STANDARD PROCEDURES FOR...
10. 48 CFR 19.804-6 - Indefinite delivery contracts.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Indefinite delivery contracts. 19.804-6 Section 19.804-6 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION...) Program) 19.804-6 Indefinite delivery contracts. (a) Separate offers and acceptances must not be made...
11. 49 CFR 1242.11 - Administration-bridges and buildings (account XX-19-03).
Code of Federal Regulations, 2011 CFR
2011-10-01
... RAILROADS 1 Operating Expenses-Way and Structures § 1242.11 Administration—bridges and buildings (account XX-19-03). Separate common administration—bridges and buildings expenses between freight and passenger... 49 Transportation 9 2011-10-01 2011-10-01 false Administration-bridges and buildings (account...
12. 49 CFR 192.165 - Compressor stations: Liquid removal.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 3 2011-10-01 2011-10-01 false Compressor stations: Liquid removal. 192.165... Components § 192.165 Compressor stations: Liquid removal. (a) Where entrained vapors in gas may liquefy under... introduction of those liquids in quantities that could cause damage. (b) Each liquid separator used to...
13. 48 CFR 204.1202 - Solicitation provision.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Solicitation provision... 204.1202 Solicitation provision. When using the provision at FAR 52.204-8, Annual Representations and...; and (2) Do not include separately in the solicitation the following provisions, which are included...
14. 46 CFR 169.317 - Accommodations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Accommodations. 169.317 Section 169.317 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction... and noise. (d) Each person on board must have a separate berth which is of sufficient size...
15. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...
16. 45 CFR 2555.410 - Comparable facilities.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 4 2011-10-01 2011-10-01 false Comparable facilities. 2555.410 Section 2555.410... § 2555.410 Comparable facilities. A recipient may provide separate toilet, locker room, and shower facilities on the basis of sex, but such facilities provided for students of one sex shall be comparable...
17. 47 CFR 36.352 - Other property plant and equipment expenses-Account 6510 (Class B telephone companies); Accounts...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Other property plant and equipment expenses... Plant Expenses-Other § 36.352 Other property plant and equipment expenses—Account 6510 (Class B... based on the separation of Account 2001—Telecommunications Plant in Service. Network Operations Expenses...
18. 46 CFR 179.330 - Watertight doors.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Watertight doors. 179.330 Section 179.330 Shipping COAST... doors. (a) Hinged watertight doors are not permitted in bulkheads required by § 179.210 or § 179.212 unless the vessel will not proceed more than 20 nautical miles from shore and: (1) The door separates...
19. 47 CFR 32.7990 - Nonregulated net income.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Nonregulated net income. 32.7990 Section 32... Nonregulated net income. (a) This account shall be used by those companies who offer nonregulated activities... shall be recorded on separate books of account for such operations. Only the net of the total...
20. 49 CFR 1242.19 - Electric power systems (account XX-19-21).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Electric power systems (account XX-19-21). 1242.19... Structures § 1242.19 Electric power systems (account XX-19-21). Separate common expenses on basis of common expenses of electric power purchased or produced for motive power (accounts XX-51-68 and XX-52-68)....
1. 43 CFR 3596.2 - Disposal of waste.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Disposal of waste. 3596.2 Section 3596.2... OPERATIONS Waste From Mining or Milling § 3596.2 Disposal of waste. The operator/lessee shall dispose of all wastes resulting from the mining, reduction, concentration or separation of mineral substances...
2. 42 CFR 498.54 - Joint hearings.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 5 2011-10-01 2011-10-01 false Joint hearings. 498.54 Section 498.54 Public Health... PROGRAM Hearings § 498.54 Joint hearings. When two or more affected parties have requested hearings and... joint hearings are held, a single record of the preceedings is made and a separate decision issued...
3. 48 CFR 203.170 - Business practices.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Business practices. 203..., DEPARTMENT OF DEFENSE GENERAL IMPROPER BUSINESS PRACTICES AND PERSONAL CONFLICTS OF INTEREST Safeguards 203.170 Business practices. To ensure the separation of functions for oversight, source...
4. 46 CFR 35.03-15 - Shipboard stowage-TB/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Shipboard stowage-TB/ALL. 35.03-15 Section 35.03-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Work Vests § 35.03-15 Shipboard stowage—TB/ALL. (a) The approved buoyant work vests shall be stowed separately from the...
5. 46 CFR 30.10-13 - Cofferdam-TB/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Cofferdam-TB/ALL. 30.10-13 Section 30.10-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-13 Cofferdam—TB/ALL. The term cofferdam means a void or empty space separating two or more compartments for...
6. 49 CFR 1242.55 - Administration (account XX-51-01).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Administration (account XX-51-01). 1242.55 Section 1242.55 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF...
7. 49 CFR 1242.57 - Dispatching trains (account XX-51-58).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Dispatching trains (account XX-51-58). 1242.57 Section 1242.57 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF...
8. 49 CFR 1242.59 - Train inspection and lubrication (account XX-51-62).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Train inspection and lubrication (account XX-51-62). 1242.59 Section 1242.59 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF...
9. 43 CFR 3101.2-2 - Acquired lands.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Acquired lands. 3101.2-2 Section 3101.2-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Acquired lands. An acreage limitation separate from, but equal to the acreage limitation for public...
10. 46 CFR 58.25-10 - Main and auxiliary steering gear.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 2 2011-10-01 2011-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout...
11. 42 CFR 457.355 - Presumptive eligibility.
Code of Federal Regulations, 2011 CFR
2011-10-01
... under the separate child health program, pending the screening process and a final determination of... 42 Public Health 4 2011-10-01 2011-10-01 false Presumptive eligibility. 457.355 Section 457.355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...
12. 45 CFR 86.17 - Transition plans.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 1 2011-10-01 2011-10-01 false Transition plans. 86.17 Section 86.17 Public... Transition plans. (a) Submission of plans. An institution to which § 86.16 applies and which is composed of more than one administratively separate unit may submit either a single transition plan applicable...
13. 45 CFR 618.230 - Transition plans.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 3 2011-10-01 2011-10-01 false Transition plans. 618.230 Section 618.230 Public... Coverage § 618.230 Transition plans. (a) Submission of plans. An institution to which § 618.225 applies and... plan applicable to all such units, or a separate transition plan applicable to each such unit....
14. 49 CFR 1242.22 - Shop buildings-locomotives (account XX-19-24).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Shop buildings-locomotives (account XX-19-24). 1242.22 Section 1242.22 Transportation Other Regulations Relating to Transportation (Continued) SURFACE... Structures § 1242.22 Shop buildings—locomotives (account XX-19-24). Separate common expenses according...
15. 47 CFR 36.504 - Accumulated depreciation-Property held for future telecommunications use-Account 3200.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Accumulated depreciation-Property held for future telecommunications use-Account 3200. 36.504 Section 36.504 Telecommunication FEDERAL... PROCEDURES FOR SEPARATING TELECOMMUNICATIONS PROPERTY COSTS, REVENUES, EXPENSES, TAXES AND RESERVES...
16. 46 CFR 153.430 - Heat transfer systems; general.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Heat transfer systems; general. 153.430 Section 153.430... Temperature Control Systems § 153.430 Heat transfer systems; general. Each cargo cooling system required by... separated from all other cooling and heating systems; and (c) Allow manual regulation of the system's...
17. 46 CFR 153.436 - Heat transfer fluids: compatibility with cargo.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Heat transfer fluids: compatibility with cargo. 153.436... Equipment Cargo Temperature Control Systems § 153.436 Heat transfer fluids: compatibility with cargo. A heat transfer fluid separated from the cargo by only one wall (for example, the heat transfer fluid in a...
18. 46 CFR 32.56-55 - Control spaces-T/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent...
19. 46 CFR 171.095 - Machinery space bulkhead.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Machinery space bulkhead. 171.095 Section 171.095... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.095 Machinery space... transverse watertight bulkheads to separate the machinery space from the remainder of the vessel....
20. 46 CFR 183.392 - Radiotelephone installations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.392 Radiotelephone installations. A separate circuit, with overcurrent protection at the main distribution panel, must be provided... 46 Shipping 7 2011-10-01 2011-10-01 false Radiotelephone installations. 183.392 Section...
1. 47 CFR 73.611 - Reference points and distance computations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Reference points and distance computations. 73... SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.611 Reference points and distance... reference points shall be used by the Commission in determining assignment separations between...
2. Explaining the Development of False Memories.
ERIC Educational Resources Information Center
Reyna, Valerie F.; Holliday, Robyn; Marche, Tammy
2002-01-01
Reviews explanatory dimensions of children's false memory relevant to forensic practice: measurement, development, social factors, individual differences, varieties of memories and memory judgments, and varieties of procedures inducing false memories. Asserts that recent studies fail to use techniques that separate acquiescence from memory…
3. MSPI False Indication Probability Simulations
SciTech Connect
Dana Kelly; Kurt Vedros; Robert Youngblood
2011-03-01
This paper examines false indication probabilities in the context of the Mitigating System Performance Index (MSPI), in order to investigate the pros and cons of different approaches to resolving two coupled issues: (1) sensitivity to the prior distribution used in calculating the Bayesian-corrected unreliability contribution to the MSPI, and (2) whether (in a particular plant configuration) to model the fuel oil transfer pump (FOTP) as a separate component, or integrally to its emergency diesel generator (EDG). False indication probabilities were calculated for the following situations: (1) all component reliability parameters at their baseline values, so that the true indication is green, meaning that an indication of white or above would be false positive; (2) one or more components degraded to the extent that the true indication would be (mid) white, and “false” would be green (negative) or yellow (negative) or red (negative). In key respects, this was the approach taken in NUREG-1753. The prior distributions examined were the constrained noninformative (CNI) prior used currently by the MSPI, a mixture of conjugate priors, the Jeffreys noninformative prior, a nonconjugate log(istic)-normal prior, and the minimally informative prior investigated in (Kelly et al., 2010). The mid-white performance state was set at ?CDF = ?10 ? 10-6/yr. For each simulated time history, a check is made of whether the calculated ?CDF is above or below 10-6/yr. If the parameters were at their baseline values, and ?CDF > 10-6/yr, this is counted as a false positive. Conversely, if one or all of the parameters are set to values corresponding to ?CDF > 10-6/yr but that time history’s ?CDF < 10-6/yr, this is counted as a false negative indication. The false indication (positive or negative) probability is then estimated as the number of false positive or negative counts divided by the number of time histories (100,000). Results are presented for a set of base case parameter values
4. False color viewing device
DOEpatents
Kronberg, J.W.
1992-10-20
A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs.
5. False color viewing device
DOEpatents
Kronberg, James W.
1992-01-01
A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.
6. False color viewing device
DOEpatents
Kronberg, J.W.
1991-05-08
This invention consists of a viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching, the user`s eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.
7. 49 CFR Figure 1c to Subpart B of... - Example of a Passenger Compartment Including a Vestibule Connected by an Open Passageway and...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Example of a Passenger Compartment Including a Vestibule Connected by an Open Passageway and Excluding a Vestibule Separated by an Interior Door-§§ 238... Passageway and Excluding a Vestibule Separated by an Interior Door—§§ 238.113 and 238.114 ER01FE08.004...
8. False Color Bands
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
In a gray scale image, the suble variations seen in this false color image are almost impossible to identify. Note the orange band in the center of the frame, and the bluer bands to either side of it.
Image information: VIS instrument. Latitude 87, Longitude 65.5 East (294.5 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
9. Moon - False Color Mosaic
NASA Technical Reports Server (NTRS)
1992-01-01
This false-color mosaic was constructed from a series of 53 images taken through three spectral filters by Galileo's imaging system as the spacecraft flew over the northern regions of the Moon on December 7, 1992. The part of the Moon visible from Earth is on the left side in this view. The color mosaic shows compositional variations in parts of the Moon's northern hemisphere. Bright pinkish areas are highlands materials, such as those surrounding the oval lava-filled Crisium impact basin toward the bottom of the picture. Blue to orange shades indicate volcanic lava flows. To the left of Crisium, the dark blue Mare Tranquillitatis is richer in titanium than the green and orange maria above it. Thin mineral-rich soils associated with relatively recent impacts are represented by light blue colors; the youngest craters have prominent blue rays extending from them. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.
10. North Polar False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
This full resolution image contains dunes, and small areas of 'blue' which may represent fresh (ie. not dust covered) frost or ice.
Image information: VIS instrument. Latitude 85, Longitude 235.8 East (124.2 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
11. False Color Aurora
NASA Technical Reports Server (NTRS)
1997-01-01
Data from NASA's Galileo spacecraft were used to produce this false-color composite of Jupiter's northern aurora on the night side of the planet. The height of the aurora, the thickness of the auroral arc, and the small-scale structure are revealed for the first time. Images in Galileo's red, green, and clear filters are displayed in red, green, and blue respectively. The smallest resolved features are tens of kilometers in size, which is a ten-fold improvement over Hubble Space Telescope images and a hundred-fold improvement over ground-based images.
The glow is caused by electrically charged particles impinging on the atmosphere from above. The particles travel along Jupiter's magnetic field lines, which are nearly vertical at this latitude. The auroral arc marks the boundary between the 'closed' field lines that are attached to the planet at both ends and the 'open' field lines that extend out into interplanetary space. At the boundary the particles have been accelerated over the greatest distances, and the glow is especially intense.
The latitude-longitude lines refer to altitudes where the pressure is 1 bar. The image shows that the auroral emissions originate about 500 kilometers (about 310 miles) above this surface. The colored background is light scattered from Jupiter's bright crescent, which is out of view to the right. North is at the top. The images are centered at 57 degrees north and 184 degrees west and were taken on April 2, 1997 at a range of 1.7 million kilometers (1.05 million miles) by Galileo's Solid State Imaging (SSI) system.
The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at: http:// galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.
12. 49 CFR 1242.87 - Joint facility-debit and credit and casualties and insurance (accounts 37-63-00, 38-63-00 and 50...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 9 2011-10-01 2011-10-01 false Joint facility-debit and credit and casualties and insurance (accounts 37-63-00, 38-63-00 and 50-63-00). 1242.87 Section 1242.87 Transportation Other... casualties and insurance (accounts 37-63-00, 38-63-00 and 50-63-00). Separate the common expenses...
13. Positive consequences of false memories.
PubMed
Howe, Mark L; Garner, Sarah R; Patel, Megan
2013-01-01
Previous research is replete with examples of the negative consequences of false memories. In the current research, we provide a different perspective on false memories and their development and demonstrate that false memories can have positive consequences. Specifically, we examined the role false memories play in subsequent problem-solving tasks. Children and adults studied and recalled neutral or survival-relevant lists of associated words. They then solved age-normed compound remote associates, some of whose solutions had been primed by false memories created when studying the previous lists. The results showed that regardless of age: (a) survival-related words were not only better recollected but were also more susceptible than neutral words to false memory illusions; and (b) survival-related false memories were better than neutral false memories as primes for problem-solving. These findings are discussed in the context of recent speculation concerning the positive consequences of false memories, and the adaptive nature of reconstructive memory.
14. False Position, Double False Position and Cramer's Rule
ERIC Educational Resources Information Center
Boman, Eugene
2009-01-01
We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.
15. False memories for aggressive acts.
PubMed
Laney, Cara; Takarangi, Melanie K T
2013-06-01
Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed.
16. The Kepler False Positive Table
Bryson, Steve; Kepler False Positive Working Group
2015-01-01
The Kepler Space Telescope has detected thousands of candidate exoplanets by observing transit signals in a sample of more than 190,000 stars. Many of these transit signals are false positives, defined as a transit-like signal that is not due to a planet orbiting the target star (or a bound companion if the target is a multiple-star system). Astrophysical causes of false positives include background eclipsing binaries, planetary transits not associated with the target star, and non-planetary eclipses of the target star by stellar companions. The fraction of Kepler planet candidates that are false positives ranges from about 10% at high Galactic latitudes to 40% at low Galactic latitudes. Creating a high-reliability planet candidate catalog for statistical studies such as occurrence rate calculations requires removing clearly identified false positives.The Kepler Object of Interest (KOI) catalog at the NExScI NASA Exoplanet Archive flags false positives, and will soon provide a high-level classification of false positives, but lacks detailed description of why a KOI was determined to be a false positive. The Kepler False Positive Working Group (FPWG) examines each false positive in detail to certify that it is correctly identified as a false positive, and determines the primary reason(s) a KOI is classified as a false positive. The work of the FPWG will be published as the Kepler False Positive Table, hosted at the NExScI NASA Exoplanet Archive.The Kepler False Positive Table provides detailed information on the evidence for background binaries, transits caused by stellar companions, and false alarms. In addition to providing insight into the Kepler false positive population, the false positive table gives information about the background binary population and other areas of astrophysical interest. Because a planet around a star not associated with the target star is considered a false positive, the false positive table likely contains further planet candidates
17. Sleep deprivation and false memories.
PubMed
Frenda, Steven J; Patihis, Lawrence; Loftus, Elizabeth F; Lewis, Holly C; Fenn, Kimberly M
2014-09-01
Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.
18. Reduced False Memory after Sleep
ERIC Educational Resources Information Center
Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.
2009-01-01
Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False…
19. Study modality and false recall.
PubMed
Smith, Rebekah E; Engle, Randall W
2011-01-01
False memories occur when individuals mistakenly report an event as having taken place when that event did not in fact occur. The DRM (Deese, 1959; Roediger & McDermott, 1995) paradigm provides an effective technique for creating and investigating false memories. In this paradigm participants study a list of words (e.g., SOUR, CANDY,…) that are highly associated to a non-presented critical item (e.g., SWEET). The study phase is followed by a test of memory for the study list words. Researchers typically find very high levels of false recall of the critical non-presented item. However, the likelihood of falsely remembering the non-presented critical items can be reduced by presenting studied associates visually rather than auditorally (e.g., Smith & Hunt, 1998). This is referred to as the modality effect in false memory. The current study investigated the role of resource availability in the expression of this modality effect in false recall. In Experiment 1 false recall was reduced in the visual study presentation condition relative to the auditory condition for participants with higher working memory capacity, but not for participants with lower working memory capacity. In Experiment 2 the effect of study modality on false recall was eliminated by the addition of a divided attention task at encoding. Both studies support the proposal that resource availability plays a role in the expression of the modality effect in the DRM paradigm (Smith, Lozito, & Bayen, 2005).
20. Tunneling decay of false kinks
Dupuis, Éric; Gobeil, Yan; MacKenzie, Richard; Marleau, Luc; Paranjape, M. B.; Ung, Yvan
2015-07-01
We consider the decay of "false kinks," that is, kinks formed in a scalar field theory with a pair of degenerate symmetry-breaking false vacua in 1 +1 dimensions. The true vacuum is symmetric. A second scalar field and a peculiar potential are added in order for the kink to be classically stable. We find an expression for the decay rate of a false kink. As with any tunneling event, the rate is proportional to exp (-SE) where SE is the Euclidean action of the bounce describing the tunneling event. This factor varies wildly depending on the parameters of the model. Of interest is the fact that for certain parameters SE can get arbitrarily small, implying that the kink is only barely stable. Thus, while the false vacuum itself may be very long-lived, the presence of kinks can give rise to rapid vacuum decay.
1. False allegation of child abduction.
PubMed
Canning, Kathleen E; Hilts, Mark A; Muirhead, Yvonne E
2011-05-01
Cases in which a child has been falsely reported as missing or abducted can be extremely challenging to the law enforcement agencies responsible for their investigation. In the absence of a witnessed abduction or an obvious crime scene, it is difficult to determine whether a child has actually been abducted or has become a victim of a homicide and a false allegation. The purpose of this study was to examine falsely alleged kidnapping cases and identify successful investigative strategies. Sixty-one adjudicated false allegation cases involving 66 victims were analyzed. The mean age of the victim was 5 years. Victims came from generally unstable, high-risk family situations and were killed primarily by biological parents. Victims were killed because they were unwanted or viewed as an obstacle to a desired goal, or they were victims of abuse or maltreatment that ended in fatality.
2. Mimas Showing False Colors #1
NASA Technical Reports Server (NTRS)
2005-01-01
False color images of Saturn's moon, Mimas, reveal variation in either the composition or texture across its surface.
During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).
The image at the left is a narrow angle clear-filter image, which was separately processed to enhance the contrast in brightness and sharpness of visible features. The image at the right is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined into a single black and white picture that isolates and maps regional color differences. This 'color map' was then superimposed over the clear-filter image at the left.
The combination of color map and brightness image shows how the color differences across the Mimas surface materials are tied to geological features. Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.
Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of each image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in
3. Bubbling the false vacuum away
SciTech Connect
Gleiser, M.; Rogers, B.; Thorarinson, J.
2008-01-15
We investigate the role of nonperturbative, bubblelike inhomogeneities on the decay rate of false-vacuum states in two- and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum, as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubblelike inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay--known as resonant nucleation--is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and crossover. Possible applications are briefly discussed.
4. Tunneling decay of false vortices
Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han
2013-10-01
We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.
5. Sleep Loss Produces False Memories
PubMed Central
Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich
2008-01-01
People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., “night”, “dark”, “coal”,…), lacking the strongest common associate or theme word (here: “black”). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss. PMID:18946511
6. The Danger of False Dichotomies.
ERIC Educational Resources Information Center
LaBoskey, Vicky Kubler
1998-01-01
Responds to an article that examined 10 dichotomies in teacher education (SP 527 128), suggesting that too much time and energy are spent debating false dichotomies and addressing two specific dichotomies (preservice versus inservice and campus versus school site). Recommends that professional educators pool their energy and collaborate (rather…
7. Evolutionary Psychology and False Confession
ERIC Educational Resources Information Center
Bering, Jesse M.; Shackelford, Todd K.
2005-01-01
This paper presents comments on Kassin's review, (see record 2005-03019-002) of the psychology of false confessions. The authors note that Kassin's review makes a compelling argument for the need for legal reform in police interrogation practices. Because his work strikes at the heart of the American criminal justice system--its fairness--the…
8. Sleep deprivation and false confessions
PubMed Central
Frenda, Steven J.; Berkowitz, Shari R.; Loftus, Elizabeth F.; Fenn, Kimberly M.
2016-01-01
False confession is a major contributor to the problem of wrongful convictions in the United States. Here, we provide direct evidence linking sleep deprivation and false confessions. In a procedure adapted from Kassin and Kiechel [(1996) Psychol Sci 7(3):125–128], participants completed computer tasks across multiple sessions and repeatedly received warnings that pressing the “Escape” key on their keyboard would cause the loss of study data. In their final session, participants either slept all night in laboratory bedrooms or remained awake all night. In the morning, all participants were asked to sign a statement, which summarized their activities in the laboratory and falsely alleged that they pressed the Escape key during an earlier session. After a single request, the odds of signing were 4.5 times higher for the sleep-deprived participants than for the rested participants. These findings have important implications and highlight the need for further research on factors affecting true and false confessions. PMID:26858426
9. Sleep loss produces false memories.
PubMed
Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich
2008-01-01
People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",...), lacking the strongest common associate or theme word (here: "black"). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.
10. Outcome Knowledge and False Belief
PubMed Central
Ghrear, Siba E.; Birch, Susan A. J.; Bernstein, Daniel M.
2016-01-01
Virtually every social interaction involves reasoning about the perspectives of others, or ‘theory of mind (ToM).’ Previous research suggests that it is difficult to ignore our current knowledge when reasoning about a more naïve perspective (i.e., the curse of knowledge). In this Mini Review, we discuss the implications of the curse of knowledge for certain aspects of ToM. Particularly, we examine how the curse of knowledge influences key measurements of false belief reasoning. In closing, we touch on the need to develop new measurement tools to discern the mechanisms involved in the curse of knowledge and false belief reasoning, and how they develop across the lifespan. PMID:26903922
11. Does sleep promote false memories?
PubMed
Darsaud, Annabelle; Dehon, Hedwige; Lahl, Olaf; Sterpenich, Virginie; Boly, Mélanie; Dang-Vu, Thanh; Desseilles, Martin; Gais, Stephen; Matarazzo, Luca; Peters, Frédéric; Schabus, Manuel; Schmidt, Christina; Tinguely, Gilberte; Vandewalle, Gilles; Luxen, André; Maquet, Pierre; Collette, Fabienne
2011-01-01
Memory is constructive in nature so that it may sometimes lead to the retrieval of distorted or illusory information. Sleep facilitates accurate declarative memory consolidation but might also promote such memory distortions. We examined the influence of sleep and lack of sleep on the cerebral correlates of accurate and false recollections using fMRI. After encoding lists of semantically related word associates, half of the participants were allowed to sleep, whereas the others were totally sleep deprived on the first postencoding night. During a subsequent retest fMRI session taking place 3 days later, participants made recognition memory judgments about the previously studied associates, critical theme words (which had not been previously presented during encoding), and new words unrelated to the studied items. Sleep, relative to sleep deprivation, enhanced accurate and false recollections. No significant difference was observed in brain responses to false or illusory recollection between sleep and sleep deprivation conditions. However, after sleep but not after sleep deprivation (exclusive masking), accurate and illusory recollections were both associated with responses in the hippocampus and retrosplenial cortex. The data suggest that sleep does not selectively enhance illusory memories but rather tends to promote systems-level consolidation in hippocampo-neocortical circuits of memories subsequently associated with both accurate and illusory recollections. We further observed that during encoding, hippocampal responses were selectively larger for items subsequently accurately retrieved than for material leading to illusory memories. The data indicate that the early organization of memory during encoding is a major factor influencing subsequent production of accurate or false memories.
12. False advertising in the greenhouse?
Banse, K.
1991-12-01
Most scientists are convinced of the importance of their own research subjects. Broecker [1991] has deplored the temptation, if not the tendency, to go overboard and exaggerate this importance once funding enters the mind. In particular, he alleges inflated or even false claims by biological (and other) oceanographers regarding the relevance of their research to the "greenhouse effect," caused by the anthropogenic enhancement of the atmospheric CO2 content. He writes [Broecker, 1991, p. 191]: "In my estimation, on any list of subjects requiring intense study with regard to the prediction of the consequences of CO2 buildup in the atmosphere, I would place marine biological cycles near the bottom."
13. Cape Verde in False Color
NASA Technical Reports Server (NTRS)
2007-01-01
A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this false-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days.
This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).
14. Dusty Crater In False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
This false color image of a crater rim illustrates just how complete the dust cover can be. The small white/blue regions on the rim are of areas where the dust cover has been removed - due to heating on sun facing slopes or by gravitational effects.
Image information: VIS instrument. Latitude 70.1, Longitude 352.8 East (7.2 West). 40 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
15. Opportunity View of 'Gilbert' Layer (False Color)
NASA Technical Reports Server (NTRS)
2008-01-01
This view from NASA's Mars Exploration Rover Opportunity shows bedock within a stratigraphic layer informally named 'Gilbert,' which is the rover's next target after completing an examination of three stratigtaphic layers forming a bright band around the inside of Victoria Crater. The rover will descend deeper into the crater to reach the Gilbert layer.
Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:30 p.m. during the rover's 1,429th Martian day, of sol (Jan. 31, 2008).
This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.
16. Opportunity View of 'Lyell' Layer (False Color)
NASA Technical Reports Server (NTRS)
2008-01-01
This view from NASA's Mars Exploration Rover Opportunity shows bedrock within a stratigraphic layer informally named 'Lyell,' which is the lowermost of three layers the rover has examined at a bright band around the inside of Victoria Crater.
Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:21 p.m. during the rover's 1,433rd Martian day, of sol (Feb. 4, 2008).
This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.
17. View from Spirit's Overwintering Position (False Color)
NASA Technical Reports Server (NTRS)
2008-01-01
NASA's Mars Exploration Rover Spirit has this view northward from the position at the north edge of the 'Home Plate' plateau where the rover will spend its third Martian winter.
Husband Hill is on the horizon. The dark area in the middle distance is 'El Dorado' sand dune field.
Spirit used its panoramic camera (Pancam) to capture this image during the rover's 1,448th Martian day, of sol (Jan. 29, 2008).
This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.
18. Ice Surfaces In False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
This full resolution image shows a marked difference in the 'blueness' of the ice surfaces. The lower (presumably older) surface is oranger and the top (presumably younger) surface is blue. This may represent the fresher ice of the upper surface which has not yet covered with as much dust as the lower surface.
Image information: VIS instrument. Latitude 80.8, Longitude 302.1 East (57.9 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
19. Polar Layers in False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
This image again illustrates the oranger/bluer nature of the polar layers.
Image information: VIS instrument. Latitude 80.6, Longitude 70.2 East (289.8 West). 40 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
20. Sand Sea in False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
This image is of part of the northern sand sea. The small dunes in the image are bluer than the ice/dust filled central crater.
Image information: VIS instrument. Latitude 73.7, Longitude 323 East (37 West). 40 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
1. Mimas Showing False Colors #2
NASA Technical Reports Server (NTRS)
2005-01-01
This false color image of Saturn's moon Mimas reveals variation in either the composition or texture across its surface.
During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).
This image is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined with a single black and white picture that isolates and maps regional color differences to create the final product.
Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.
Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of the image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil.
This image was obtained when the Cassini spacecraft was above 25 degrees south, 134 degrees west latitude and longitude. The Sun-Mimas-spacecraft angle was 45 degrees and north is at the top.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian
2. Southern Spring in False Color
NASA Technical Reports Server (NTRS)
2004-01-01
[figure removed for brevity, see original site]
The Odyssey spacecraft has completed a full Mars year of observations of the red planet. For the next several weeks the Image of the Day will look back over this first mars year. It will focus on four themes: 1) the poles - with the seasonal changes seen in the retreat and expansion of the caps; 2) craters - with a variety of morphologies relating to impact materials and later alteration, both infilling and exhumation; 3) channels - the clues to liquid surface flow; and 4) volcanic flow features. While some images have helped answer questions about the history of Mars, many have raised new questions that are still being investigated as Odyssey continues collecting data as it orbits Mars.
This image was collected June 25, 2003 during the southern spring season. This false color image shows both the layered ice cap and darker 'spots' that are seen only when the sun first lights the polar surface.
Image information: VIS instrument. Latitude -82.3, Longitude 306 East (54 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the
3. White Rock in False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.
This false color image shows the wind eroded deposit in Pollack Crater called 'White Rock'. This image was collected during the Southern Fall Season.
Image information: VIS instrument. Latitude -8, Longitude 25.2 East (334.8 West). 0 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of
4. Iani Chaos in False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.
This false color image of a portion of the Iani Chaos region was collected during the Southern Fall season.
Image information: VIS instrument. Latitude -2.6 Longitude 342.4 East (17.6 West). 36 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The
5. Separated Shoulder
MedlinePlus
Separated shoulder Overview By Mayo Clinic Staff A separated shoulder is an injury to the ligaments that hold your collarbone (clavicle) to your shoulder blade. In a mild separated shoulder, the ligaments ...
6. 49 CFR 520.2 - Policy.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 6 2011-10-01 2011-10-01 false Policy. 520.2 Section 520.2 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT... affect the quality of the human environment....
7. 48 CFR 232.503 - Postaward matters.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....
8. 48 CFR 232.502 - Preaward matters.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....
9. 48 CFR 970.0470 - Department of Energy Directives.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Department of Energy Directives. 970.0470 Section 970.0470 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY... Energy Directives....
10. 48 CFR 225.7703 - Acquisition of products or services other than small arms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Acquisition of products or services other than small arms. 225.7703 Section 225.7703 Federal Acquisition Regulations System DEFENSE... than small arms....
11. 47 CFR 10.300 - Alert aggregator. [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Alert aggregator. 10.300 Section 10.300 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM System Architecture § 10.300 Alert aggregator....
12. 47 CFR 10.310 - Federal alert gateway. [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Federal alert gateway. 10.310 Section 10.310 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM System Architecture § 10.310 Federal alert gateway....
13. 48 CFR 931.205 - Selected costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Selected costs. 931.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 931.205 Selected costs....
14. 48 CFR 31.205 - Selected costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Selected costs. 31.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.205 Selected costs....
15. 48 CFR 1331.205 - Selected costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Selected costs. 1331.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 1331.205 Selected costs....
16. 48 CFR 970.3102-05-30 - Patent costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Patent costs. 970.3102-05... SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Contract Cost Principles and Procedures 970.3102-05-30 Patent costs....
17. 48 CFR 970.3102-05 - Selected costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Selected costs. 970.3102... SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Contract Cost Principles and Procedures 970.3102-05 Selected costs....
18. 48 CFR 1231.205 - Selected costs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Selected costs. 1231.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 1231.205 Selected costs....
19. 48 CFR 628.309 - Contract clauses for workers' compensation insurance.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Contract clauses for workers' compensation insurance. 628.309 Section 628.309 Federal Acquisition Regulations System DEPARTMENT... workers' compensation insurance....
20. 48 CFR 53.301-1423 - Inventory Verification Survey.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Inventory Verification Survey. 53.301-1423 Section 53.301-1423 Federal Acquisition Regulations System FEDERAL ACQUISITION... Survey. ER05AP04.000...
1. 48 CFR 970.0370 - Management Controls and Improvements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Improper Business Practices and Personal Conflicts of Interest 970.0370 Management Controls and Improvements. ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Management Controls...
2. 48 CFR 1327.201 - Patent and copyright infringement liability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Patent and copyright... GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Patents and Copyrights 1327.201 Patent and copyright infringement liability....
3. 48 CFR 27.201 - Patent and copyright infringement liability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Patent and copyright... REGULATION GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Patents and Copyrights 27.201 Patent and copyright infringement liability....
4. 48 CFR 1427.201 - Patent and copyright infringement liability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Patent and copyright... INTERIOR GENERAL CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Patents and Copyrights 1427.201 Patent and copyright infringement liability....
5. 48 CFR 1816.402-2 - Performance incentives.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Performance incentives. 1816.402-2 Section 1816.402-2 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE... Performance incentives....
6. 48 CFR 250.104 - Residual powers.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....
7. 48 CFR 970.5001 - Residual powers.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....
8. 48 CFR Appendix - Federal Acquisition Regulation (FAR) Index
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Federal Acquisition Regulation (FAR) Index Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT... (IFMS) Contract clause. FAR Index Federal Acquisition Regulation (FAR) Index Editorial Note:...
9. 43 CFR 2912.1 - Nature of interest.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Nature of interest. 2912.1 Section 2912.1 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Nature of interest....
10. 49 CFR 236.764 - Locking, lever operated.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....
11. 48 CFR 236.606 - Negotiations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Negotiations. 236.606 Section 236.606 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...-Engineer Services 236.606 Negotiations....
12. 48 CFR 249.110 - Settlement negotiation memorandum.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Settlement negotiation... Settlement negotiation memorandum. Follow the procedures at PGI 249.110 for preparation of a settlement negotiation memorandum....
13. 48 CFR 19.808 - Contract negotiation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract negotiation. 19.808 Section 19.808 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC....808 Contract negotiation....
14. 48 CFR 619.808 - Contract negotiation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Contract negotiation. 619.808 Section 619.808 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS... Contract negotiation....
15. 48 CFR 836.606 - Negotiations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Negotiations. 836.606 Section 836.606 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS SPECIAL CATEGORIES... Negotiations....
16. 42 CFR 5a.2 - Applicability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false Applicability. 5a.2 Section 5a.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS RURAL PHYSICIAN... Public Health Service Act....
17. 48 CFR 25.702 - Prohibition on contracting with entities that conduct restricted business operations in Sudan.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Prohibition on contracting with entities that conduct restricted business operations in Sudan. 25.702 Section 25.702 Federal... operations in Sudan....
18. 43 CFR 3103.4 - Production incentives.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Production incentives. 3103.4 Section 3103.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Production incentives....
19. 47 CFR 76.227 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false 76.227 Section 76.227 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.227...
20. 49 CFR 369.5 - Records.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 5 2011-10-01 2011-10-01 false Records. 369.5 Section 369.5 Transportation Other... TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS REPORTS OF MOTOR CARRIERS § 369.5 Records. Books, records... Records....
1. 47 CFR 27.59 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 27.59 Section 27.59 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.59...
2. 48 CFR 970.3770 - Facilities management.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Facilities management. 970... REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Facilities Management Contracting 970.3770 Facilities management....
3. 48 CFR 970.2201-2 - Overtime management.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Overtime management. 970... SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Application of Labor Policies 970.2201-2 Overtime management....
4. 48 CFR 25.703 - Prohibition on contracting with entities that engage in certain activities relating to Iran.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Prohibition on contracting with entities that engage in certain activities relating to Iran. 25.703 Section 25.703 Federal... to Iran....
5. 48 CFR 803.570 - Commercial advertising.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Commercial advertising. 803.570 Section 803.570 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS GENERAL... Commercial advertising....
6. 47 CFR 22.169 - International coordination of channel assignments.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false International coordination of channel assignments. 22.169 Section 22.169 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Licensing Requirements and Procedures Applications...
7. 47 CFR 22.107 - General application requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... PUBLIC MOBILE SERVICES Licensing Requirements and Procedures Applications and Notifications § 22.107 General application requirements. In general, applications for authorizations, assignments of... 47 Telecommunication 2 2011-10-01 2011-10-01 false General application requirements....
8. 48 CFR 225.7009 - Restriction on ball and roller bearings.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on ball and roller bearings. 225.7009 Section 225.7009 Federal Acquisition Regulations System DEFENSE ACQUISITION... roller bearings....
9. 48 CFR 519.1202 - Evaluation factor or subfactor.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Evaluation factor or subfactor. 519.1202 Section 519.1202 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION... Evaluation factor or subfactor....
10. 48 CFR 19.1202 - Evaluation factor or subfactor.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Evaluation factor or subfactor. 19.1202 Section 19.1202 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... Evaluation factor or subfactor....
11. 48 CFR 4.501 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false 4.501 Section 4.501 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Electronic Commerce in Contracting 4.501...
12. 43 CFR 3.8 - Applications referred for recommendation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Applications referred for recommendation... AMERICAN ANTIQUITIES § 3.8 Applications referred for recommendation. Applications for permits shall be referred to the Smithsonian Institution for recommendation....
13. 49 CFR 37.39 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 1 2011-10-01 2011-10-01 false 37.39 Section 37.39 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.39...
14. 48 CFR 219.502 - Setting aside acquisitions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Setting aside acquisitions..., DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Set-Asides for Small Business 219.502 Setting aside acquisitions....
15. 48 CFR 225.7004 - Restriction on acquisition of foreign buses.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on acquisition of foreign buses. 225.7004 Section 225.7004 Federal Acquisition Regulations System DEFENSE... on acquisition of foreign buses....
16. 46 CFR 308.305 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.305 Section 308.305 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE Second Seamen's War Risk Insurance § 308.305...
17. 46 CFR 308.301 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.301 Section 308.301 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE Second Seamen's War Risk Insurance § 308.301...
18. 48 CFR 245.201 - Solicitation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Solicitation. 245.201... OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Solicitation and Evaluation Procedures 245.201 Solicitation....
19. 48 CFR 239.7201 - Solicitation requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Solicitation requirements... Standards 239.7201 Solicitation requirements. Contracting officers shall ensure that all applicable Federal Information Processing Standards are incorporated into solicitations....
20. 48 CFR 1524.104 - Solicitation provisions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Solicitation provisions....104 Solicitation provisions. The Contracting Officer shall insert the provision at 1552.224-70, Social... solicitations....
1. 48 CFR 514.201-6 - Solicitation provisions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Solicitation provisions... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Solicitation of Bids 514.201-6 Solicitation provisions... solicitation....
2. 48 CFR 2116.105 - Solicitation provision.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Solicitation provision... TYPES TYPES OF CONTRACTS Selecting Contract Types 2116.105 Solicitation provision. FAR 16.105 has no... solicitations....
3. 48 CFR 606.570 - Solicitation provision.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Solicitation provision... ACQUISITION PLANNING COMPETITION REQUIREMENTS Competition Advocates 606.570 Solicitation provision. The... solicitations exceeding the simplified acquisition threshold....
4. 44 CFR 19.210 - Military and merchant marine educational institutions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Military and merchant marine... marine educational institutions. These Title IX regulations do not apply to an educational institution... the merchant marine....
5. 45 CFR 2555.210 - Military and merchant marine educational institutions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 4 2011-10-01 2011-10-01 false Military and merchant marine educational... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Coverage § 2555.210 Military and merchant marine... marine....
6. 43 CFR 11.16 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false 11.16 Section 11.16 Public Lands: Interior Office of the Secretary of the Interior NATURAL RESOURCE DAMAGE ASSESSMENTS Introduction § 11.16...
7. 43 CFR 11.19 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false 11.19 Section 11.19 Public Lands: Interior Office of the Secretary of the Interior NATURAL RESOURCE DAMAGE ASSESSMENTS Introduction § 11.19...
8. 48 CFR 243.204-70 - Definitization of change orders.
Code of Federal Regulations, 2011 CFR
2011-10-01
... REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 243.204-70 Definitization of change orders. ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Definitization of...
9. 49 CFR 178.33b - Specification 2S; inner nonrefillable plastic receptacles.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 2S; inner nonrefillable plastic receptacles. 178.33b Section 178.33b Transportation Other Regulations Relating to Transportation (Continued... nonrefillable plastic receptacles....
10. 43 CFR 1784.4 - Public participation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Public participation. 1784.4 Section 1784.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Public participation....
11. 48 CFR 1.602 - Contracting officers.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contracting officers. 1... FEDERAL ACQUISITION REGULATIONS SYSTEM Career Development, Contracting Authority, and Responsibilities 1.602 Contracting officers....
12. 48 CFR 3017.204 - Contracts.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Contracts. 3017.204... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options. 3017.204 Contracts....
13. 47 CFR 32.6362 - Other terminal equipment expense.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Other terminal equipment expense. 32.6362... Other terminal equipment expense. This account shall include expenses associated with other terminal equipment....
14. 47 CFR 32.6351 - Public telephone terminal equipment expense.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false Public telephone terminal equipment expense. 32....6351 Public telephone terminal equipment expense. This account shall include expenses associated with public telephone terminal equipment....
15. 46 CFR 308.106 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.106 Section 308.106 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Hull and Disbursements Insurance §...
16. 47 CFR 24.832 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.832 Section 24.832 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Interim Application, Licensing, and Processing Rules for Broadband PCS §...
17. 47 CFR 73.766 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
18. 46 CFR 308.201 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.201 Section 308.201 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Protection and Indemnity Insurance §...
19. 47 CFR 73.659-73.663 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
20. 46 CFR 298.34 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 298.34 Section 298.34 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Documentation §...
1. 47 CFR 22.215 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 22.215 Section 22.215 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Licensing Requirements and Procedures Competitive Bidding Procedures §...
2. 47 CFR 24.710 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.710 Section 24.710 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Competitive Bidding Procedures for Broadband PCS §...
3. 47 CFR 24.101 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.101 Section 24.101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Narrowband PCS §...
4. 47 CFR 73.3534 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false 73.3534 Section 73.3534 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Rules Applicable to All Broadcast Stations §...
5. 47 CFR 73.672 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
6. 47 CFR 24.713 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.713 Section 24.713 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Competitive Bidding Procedures for Broadband PCS §...
7. 46 CFR 308.101 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.101 Section 308.101 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Hull and Disbursements Insurance §...
8. 47 CFR 24.130 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.130 Section 24.130 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Narrowband PCS §...
9. 47 CFR 24.320 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 24.320 Section 24.320 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Competitive Bidding Procedures for Narrowband PCS §...
10. 45 CFR 1233.4 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 4 2011-10-01 2011-10-01 false 1233.4 Section 1233.4 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE INTERGOVERNMENTAL REVIEW OF ACTION PROGRAMS §...
11. 46 CFR 308.206 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false 308.206 Section 308.206 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Protection and Indemnity Insurance §...
12. 47 CFR 22.961-22.967 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 22.961-22.967 Section 22.961-22.967 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service §§...
13. 48 CFR 1511.011-79 - Information resources management.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Information resources... AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The... Resource Management, in all solicitations and contracts....
14. 48 CFR 5416.203 - Fixed-price contracts with economic price adjustment.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Fixed-price contracts with economic price adjustment. 5416.203 Section 5416.203 Federal Acquisition Regulations System DEFENSE... contracts with economic price adjustment....
15. 48 CFR 225.7005 - Restriction on certain chemical weapons antidote.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on certain chemical weapons antidote. 225.7005 Section 225.7005 Federal Acquisition Regulations System DEFENSE... on certain chemical weapons antidote....
16. 46 CFR 8.320 - Classification society authorization to issue international certificates.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Classification society authorization to issue... Classification society authorization to issue international certificates. (a) The Commandant may authorize a recognized classification society to issue certain international convention certificates. Authorization...
17. 49 CFR 236.780 - Plunger, facing point lock.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Plunger, facing point lock. 236.780 Section 236.780 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... plunger stand when the switch is locked....
18. 47 CFR 73.6023 - Distributed transmission systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....
19. 49 CFR 200.3 - Definitions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... railroads for freight transportation. ... 49 Transportation 4 2011-10-01 2011-10-01 false Definitions. 200.3 Section 200.3 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT...
20. 49 CFR Appendix B to Part 224 - Reflectorization Implementation Compliance Report
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Reflectorization Implementation Compliance Report B Appendix B to Part 224 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REFLECTORIZATION OF RAIL FREIGHT...
1. 49 CFR Appendix C to Part 224 - Guidelines for Electronic Submission of Reflectorization Implementation Compliance Reports
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Guidelines for Electronic Submission of Reflectorization Implementation Compliance Reports C Appendix C to Part 224 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF...
2. 46 CFR Appendix D to Subpart C of... - Ocean Transportation Intermediary (OTI) Group Bond Form [FMC-69
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 9 2011-10-01 2011-10-01 false Ocean Transportation Intermediary (OTI) Group Bond Form... OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial Responsibility Requirements; Claims Against...
3. 46 CFR 154.516 - Piping: Hull protection.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Piping: Hull protection. 154.516 Section 154.516 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... manifolds; and (c) Pump seals....
4. 43 CFR 3191.5 - Delegation for Indian lands.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Delegation for Indian lands. 3191.5 Section 3191.5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... lands....
5. 48 CFR 215.404 - Proposal analysis.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Proposal analysis. 215.404 Section 215.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Proposal analysis....
6. 47 CFR 74.643 - Interference to geostationary-satellites.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....
7. 47 CFR 25.219 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 25.219 Section 25.219 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.219...
8. 47 CFR 80.333 - Stations in the maritime mobile-satellite service.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Stations in the maritime mobile-satellite..., Alarm, Urgency and Safety Procedures § 80.333 Stations in the maritime mobile-satellite service. The...-satellite service....
9. 47 CFR 2.1055 - Measurements required: Frequency stability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 1 2011-10-01 2011-10-01 false Measurements required: Frequency stability. 2.1055 Section 2.1055 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Equipment Authorization...
10. 49 CFR 236.731 - Controller, circuit.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2011-10-01 2011-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...
11. 49 CFR 236.720 - Circuit, common return.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit. ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, common return. 236.720 Section...
12. 45 CFR 1627.7 - Tax sheltered annuities, retirement accounts and pensions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 4 2011-10-01 2011-10-01 false Tax sheltered annuities, retirement accounts and... SERVICES CORPORATION SUBGRANTS AND MEMBERSHIP FEES OR DUES § 1627.7 Tax sheltered annuities, retirement..., retirement account, or pension fund....
13. 48 CFR 27.204 - Patented technology under trade agreements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Patented technology under trade agreements. 27.204 Section 27.204 Federal Acquisition Regulations System FEDERAL ACQUISITION... Patented technology under trade agreements....
14. 47 CFR 32.15 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 32.15 Section 32.15 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.15...
15. 49 CFR 236.206 - Battery or power supply with respect to relay; location.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....
16. 47 CFR 25.402 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 2 2011-10-01 2011-10-01 false 25.402 Section 25.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.402...
17. 48 CFR 3032.006 - Reduction or suspension of contract payments upon finding of fraud.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Reduction or suspension of contract payments upon finding of fraud. 3032.006 Section 3032.006 Federal Acquisition Regulations System... finding of fraud....
18. 48 CFR 1616.7002 - Clause-contracts based on cost analysis (experience rated).
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Clause-contracts based on... FEHBP contracts based on cost analysis (experience rated). ... OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION...
19. 48 CFR 219.401 - General.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false General. 219.401 Section 219.401 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... point for interface with the SBA....
20. 48 CFR 252.239-7016 - Telecommunications security equipment, devices, techniques, and services.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Telecommunications... Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS... telecommunications security equipment, devices, techniques, or services to contractor telecommunications systems....
1. 49 CFR 178.346 - Specification DOT 406; cargo tank motor vehicle.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 3 2011-10-01 2011-10-01 false Specification DOT 406; cargo tank motor vehicle...) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.346 Specification DOT 406; cargo tank motor vehicle....
2. 49 CFR 178.348 - Specification DOT 412; cargo tank motor vehicle.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 3 2011-10-01 2011-10-01 false Specification DOT 412; cargo tank motor vehicle...) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.348 Specification DOT 412; cargo tank motor vehicle....
3. 49 CFR 178.347 - Specification DOT 407; cargo tank motor vehicle.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 3 2011-10-01 2011-10-01 false Specification DOT 407; cargo tank motor vehicle...) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.347 Specification DOT 407; cargo tank motor vehicle....
4. 50 CFR 38.5 - Emergency authority.
Code of Federal Regulations, 2011 CFR
2011-10-01
... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Executive Authority; Authorized... Midway Atoll National Wildlife Refuge. ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Emergency authority. 38.5 Section...
5. Decoy Methods for Assessing False Positives and False Discovery Rates in Shotgun Proteomics
PubMed Central
Wang, Guanghui; Wu, Wells W.; Zhang, Zheng; Masilamani, Shyama; Shen, Rong-Fong
2008-01-01
The potential of getting a significant number of false positives (FPs) in peptide-spectrum matches (PSMs) obtained by proteomic database search has been well-recognized. Among the attempts to assess FPs, the concomitant use of target and decoy databases is widely practiced. By adjusting filtering criteria, FPs and false discovery rate (FDR) can be controlled at a desired level. Although the target-decoy approach is gaining in popularity, subtle differences in decoy construction (e.g., reversing vs. stochastic methods), rate calculation (e.g., total vs. unique PSMs), or searching (separate vs. composite) do exist among various implementations. In the present study, we evaluated the effects of these differences on FP and FDR estimations using a rat kidney protein sample and the SEQUEST search engine as an example. On the effects of decoy construction, we found that, when a single scoring filter (XCorr) was used, stochastic methods generated a higher estimation of FPs and FDR than sequence reversing methods, likely due to an increase in unique peptides. This higher estimation could largely be attenuated by creating decoy databases similar in effective size, but not by a simple normalization with a unique-peptide coefficient. When multiple filters were applied, the differences seen between reversing and stochastic methods significantly diminished, suggesting multiple filterings reduce the dependency on how a decoy is constructed. For a fixed set of filtering criteria, FDR and FPs estimated by using unique PSMs were almost twice those using total PSMs. The higher estimation seemed to be dependent on data acquisition setup. As to the differences between performing separate or composite searches, in general, FDR estimated from separate search was about three times that from composite search. The degree of difference gradually decreased as the filtering criteria became more stringent. Paradoxically, the estimated true positives in separate search were higher when multiple
6. 19 CFR 111.32 - False information.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 19 Customs Duties 1 2010-04-01 2010-04-01 false False information. 111.32 Section 111.32 Customs... CUSTOMS BROKERS Duties and Responsibilities of Customs Brokers § 111.32 False information. A broker must... procure the giving of, any false or misleading information or testimony in any matter pending before...
7. Earth - False Color Mosaic of the Andes
NASA Technical Reports Server (NTRS)
1992-01-01
This false-color mosaic of the central part of the Andes mountains of South America (70 degrees west longitude, 19 degrees south latitude) is made up of 42 images acquired by the Galileo spacecraft from an altitude of about 25,000 kilometers (15,000 miles). A combination of visible (green) and near-infrared (0.76 and 1.0-micron) filters was chosen for this view to separate regions with distinct vegetation and soil types. The mosaic shows the area where Chile, Peru and Bolivia meet. The Pacific Coast appears at the left of the image-- Galileo captured this view as it traveled west over the Pacific Ocean, looking back at the Andes. Lakes Titicaca and Poopo are nearly black patches at the top and center, respectively; a large light-blue area below and to the left of Lake Poopo is Salar de Uyuni, a dry salt lake some 120 kilometers (75 miles) across. These lakes lie in the Altiplano, a region between the western and eastern Andes, which are covered by clouds. The vegetation-bearing Gran Chaco plains east of the Andes appear pale green. Light-blue patches in the mountains to the north are glaciers.
8. Ultracapacitor separator
DOEpatents
Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris
2001-03-06
An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.
9. Comparing recollective experience in true and false autobiographical memories.
PubMed
Heaps, C M; Nash, M
2001-07-01
This study investigated whether true autobiographical memories are qualitatively distinct from false autobiographical memories using a variation of the interview method originally reported by E. F. Loftus and J. Pickrell (1995). Participants recalled events provided by parents on 3 separate occasions and were asked to imagine true and false unremembered events. True memories were rated by both participants and observers as more rich in recollective experience and were rated by participants as more important, more emotionally intense, as having clearer imagery, and as less typical than false memories. Rehearsal frequency was used as a covariate, eliminating these effects. Imagery in true memories was most often viewed from the field perspective, whereas imagery in false memories was most often viewed from the observer perspective. More information was communicated in true memories, and true memories contained more information concerning the consequences of described events. Results suggest repeated remembering can make false memories more rich in recollective experience and more like true memories. Differences between true and false memories suggest some potentially distinct characteristics of false memories and provide insight into the process of false memory creation.
10. An Association Account of False Belief Understanding
ERIC Educational Resources Information Center
De Bruin, L. C.; Newen, A.
2012-01-01
The elicited-response false belief task has traditionally been considered as reliably indicating that children acquire an understanding of false belief around 4 years of age. However, recent investigations using spontaneous-response tasks suggest that false belief understanding emerges much earlier. This leads to a developmental paradox: if young…
11. 20 CFR 356.3 - False claims.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false False claims. 356.3 Section 356.3 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS OR STATEMENTS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 356.3 False claims. In the case of penalties assessed under 31...
12. 20 CFR 356.3 - False claims.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false False claims. 356.3 Section 356.3 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS OR STATEMENTS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 356.3 False claims. In the case of penalties assessed under 31...
13. 30 CFR 281.5 - False statements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false False statements. 281.5 Section 281.5 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 281.5 False statements. Under...
14. False discoveries and models for gene discovery.
PubMed
van den Oord, Edwin J C G; Sullivan, Patrick F
2003-10-01
In the search for genes underlying complex traits, there is a tendency to impose increasingly stringent criteria to avoid false discoveries. These stringent criteria make it hard to find true effects, and we argue that it might be better to optimize our procedures for eliminating and controlling false discoveries. Focusing on achieving an acceptable ratio of true- and false-positives, we show that false discoveries could be eliminated much more efficiently using a stepwise approach. To avoid a relatively high false discovery rate, corrections for 'multiple testing' might also be needed in candidate gene studies. If the appropriate methods are used, detecting the proportion of true effects appears to be a more important determinant of the genotyping burden than the desired false discovery rate. This raises the question of whether current models for gene discovery are shaped excessively by a fear of false discoveries.
15. An examination of two-process theories of false recognition.
PubMed
Arndt, Jason; Gould, Christine
2006-10-01
Contemporary theories of false memory suggest there are two processes that combine to produce false memory: one that increases false memory (error-inflating processes) and one that counteracts false memory (error-editing processes). Two experiments using the DRM paradigm (Deese, 1959; Roediger & McDermott, 1995) explored the influence of manipulating the number of associates studied, study item presentation frequency, backward associative strength, and study time on error-inflating and error-editing processes separately by examining speeded and unspeeded recognition decisions. The results of these studies indicate that (1) increasing the number of associates studied primarily influenced error-inflating processes; (2) increasing backward associative strength increased error-inflating processes and impaired error-editing processes; (3) increasing study item presentation frequency increased both error-inflating and error-editing processes; and (4) increasing study time had a weak effect on error-editing processes. Further, the results of these studies suggest that comprehensive theories of false memory phenomena must propose the existence of two different factors: one that increases false memory and is available early in memory retrieval, and one that usually, but not always, decreases false memory and is available later in retrieval.
16. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.
Code of Federal Regulations, 2013 CFR
2013-04-01
... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...
17. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.
Code of Federal Regulations, 2011 CFR
2011-04-01
... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...
18. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.
Code of Federal Regulations, 2010 CFR
2010-04-01
... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...
19. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.
Code of Federal Regulations, 2014 CFR
2014-04-01
... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...
20. 19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.
Code of Federal Regulations, 2012 CFR
2012-04-01
... descriptions; false marking of articles of gold or silver. 11.13 Section 11.13 Customs Duties U.S. CUSTOMS AND... gold or silver. (a) Articles which bear, or the containers which bear, false designations of origin, or.... 1405q, and shall be detained. (b) Articles made in whole or in part of gold or silver or alloys...
1. Chiral Separations
Stalcup, A. M.
2010-07-01
The main goal of this review is to provide a brief overview of chiral separations to researchers who are versed in the area of analytical separations but unfamiliar with chiral separations. To researchers who are not familiar with this area, there is currently a bewildering array of commercially available chiral columns, chiral derivatizing reagents, and chiral selectors for approaches that span the range of analytical separation platforms (e.g., high-performance liquid chromatography, gas chromatography, supercritical-fluid chromatography, and capillary electrophoresis). This review begins with a brief discussion of chirality before examining the general strategies and commonalities among all of the chiral separation techniques. Rather than exhaustively listing all the chiral selectors and applications, this review highlights significant issues and differences between chiral and achiral separations, providing salient examples from specific classes of chiral selectors where appropriate.
2. Water separator
NASA Technical Reports Server (NTRS)
Dunn, W. F.; Austin, I. G. (Inventor)
1964-01-01
An apparatus for separating liquids from gases or gaseous fluids is described. Features of the apparatus include: (1) the collection and removal of the moisture in the fluid is not dependent upon, or affected by gravity; (2) all the collected water is cyclically drained from the apparatus irrespective of the attitude of the separator; and (3) a fluid actuator is utilized to remove the collected water from the separator.
3. Battery separators.
PubMed
Arora, Pankaj; Zhang, Zhengming John
2004-10-01
The ideal battery separator would be infinitesimally thin, offer no resistance to ionic transport in electrolytes, provide infinite resistance to electronic conductivity for isolation of electrodes, be highly tortuous to prevent dendritic growths, and be inert to chemical reactions. Unfortunately, in the real world the ideal case does not exist. Real world separators are electronically insulating membranes whose ionic resistivity is brought to the desired range by manipulating the membranes thickness and porosity. It is clear that no single separator satisfies all the needs of battery designers, and compromises have to be made. It is ultimately the application that decides which separator is most suitable. We hope that this paper will be a useful tool and will help the battery manufacturers in selecting the most appropriate separators for their batteries and respective applications. The information provided is purely technical and does not include other very important parameters, such as cost of production, availability, and long-term stability. There has been a continued demand for thinner battery separators to increase battery power and capacity. This has been especially true for lithiumion batteries used in portable electronics. However, it is very important to ensure the continued safety of batteries, and this is where the role of the separator is greatest. Thus, it is essential to optimize all the components of battery to improve the performance while maintaining the safety of these cells. Separator manufacturers should work along with the battery manufacturers to create the next generation of batteries with increased reliability and performance, but always keeping safety in mind. This paper has attempted to present a comprehensive review of literature on separators used in various batteries. It is evident that a wide variety of separators are available and that they are critical components in batteries. In many cases, the separator is one of the major factors
4. Constructing rich false memories of committing crime.
PubMed
Shaw, Julia; Porter, Stephen
2015-03-01
Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive memory-retrieval techniques, participants were induced to generate criminal and noncriminal emotional false memories, and we compared these false memories with true memories of emotional events. After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components. It appears that in the context of a highly suggestive interview, people can quite readily generate rich false memories of committing crime.
5. Spirit's West Valley Panorama (False Color)
NASA Technical Reports Server (NTRS)
2008-01-01
NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.
After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.
This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.
This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle
6. 15 CFR 80.6 - False statements.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...
7. 15 CFR 80.6 - False statements.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...
8. 15 CFR 80.6 - False statements.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...
9. 15 CFR 80.6 - False statements.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...
10. 15 CFR 80.6 - False statements.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false False statements. 80.6 Section 80.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FURNISHING PERSONAL CENSUS DATA FROM CENSUS OF POPULATION SCHEDULES § 80.6...
11. How Does Distinctive Processing Reduce False Recall?
ERIC Educational Resources Information Center
Hunt, R. Reed; Smith, Rebekah E.; Dunlap, Kathryn R.
2011-01-01
False memories arising from associatively related lists are a robust phenomenon that resists many efforts to prevent it. However, a few variables have been shown to reduce this form of false memory. Explanations for how the reduction is accomplished have focused on either output monitoring processes or constraints on access, but neither idea alone…
12. Can False Memories Prime Problem Solutions?
ERIC Educational Resources Information Center
Howe, Mark L.; Garner, Sarah R.; Dewhurst, Stephen A.; Ball, Linden J.
2010-01-01
Previous research has suggested that false memories can prime performance on related implicit and explicit memory tasks. The present research examined whether false memories can also be used to prime higher order cognitive processes, namely, insight-based problem solving. Participants were asked to solve a number of compound remote associate task…
13. 30 CFR 281.5 - False statements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 2 2011-07-01 2011-07-01 false False statements. 281.5 Section 281.5 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General §...
14. Item method directed forgetting diminishes false memory.
PubMed
Marche, Tammy A; Brainerd, Charles J; Lane, David G; Loehr, Janeen D
2005-10-01
Directed forgetting may reduce DRM false memory illusion by interfering with meaning processing. Participants were presented with a list composed of six 10-word semantically associated sub-lists, and they were either (a) asked to remember all list items of (b) asked to remember all associates from sub-lists and to forget all associates from other sub-lists. All participants were requested to recall and recognise list items. Although directed forgetting effects have been previously reported only for true responses in the DRM paradigm with the list method, we also found directed forgetting for false responses with the item method. Such forgetting instructions reduced both verbatim and meaning processing, decreasing both the intrusion and the false alarm rate. These results are consistent with two-process explanations of DRM false memories, such as fuzzy-trace theory, and add to our understanding of false memory editing.
15. Emotional content of true and false memories.
PubMed
Laney, Cara; Loftus, Elizabeth F
2008-01-01
Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants' pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood events were planted using a suggestive manipulation and then compared, along several subjective dimensions, with other participants' true memories. On most emotional dimensions (e.g., how emotional was this event for you?), true and false memories were indistinguishable. On a few measures (e.g., intensity of feelings at the time of the event), true memories were more emotional than false memories in the aggregate, yet true and false memories were equally likely to be rated as uniformly emotional. These results suggest that even substantial emotional content may not reliably indicate memory accuracy.
16. Priming analogical reasoning with false memories.
PubMed
Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J
2015-08-01
Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.
17. Rapid induction of false memory for pictures.
PubMed
Weinstein, Yana; Shanks, David R
2010-07-01
Recognition of pictures is typically extremely accurate, and it is thus unclear whether the reconstructive nature of memory can yield substantial false recognition of highly individuated stimuli. A procedure for the rapid induction of false memories for distinctive colour photographs is proposed. Participants studied a set of object pictures followed by a list of words naming those objects, but embedded in the list were names of unseen objects. When subsequently shown full colour pictures of these unseen objects, participants consistently claimed that they had seen them, while discriminating with high accuracy between studied pictures and new pictures whose names did not appear in the misleading word list. These false memories can be reported with high confidence as well as the feeling of recollection. This new procedure allows the investigation of factors that influence false memory reports with ecologically valid stimuli and of the similarities and differences between true and false memories.
18. Social influence and mental routes to the production of authentic false memories and inauthentic false memories.
PubMed
Wagner, Michael F; Skowronski, John J
2017-03-09
Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others' summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants' memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts.
19. Viscoelastic properties of the false vocal fold
Chan, Roger W.
2004-05-01
The biomechanical properties of vocal fold tissues have been the focus of many previous studies, as vocal fold viscoelasticity critically dictates the acoustics and biomechanics of phonation. However, not much is known about the viscoelastic response of the ventricular fold or false vocal fold. It has been shown both clinically and in computer simulations that the false vocal fold may contribute significantly to the aerodynamics and sound generation processes of human voice production, with or without flow-induced oscillation of the false fold. To better understand the potential role of the false fold in phonation, this paper reports some preliminary measurements on the linear and nonlinear viscoelastic behavior of false vocal fold tissues. Linear viscoelastic shear properties of human false fold tissue samples were measured by a high-frequency controlled-strain rheometer as a function of frequency, and passive uniaxial tensile stress-strain response of the tissue samples was measured by a muscle lever system as a function of strain and loading rate. Elastic moduli (Young's modulus and shear modulus) of the false fold tissues were calculated from the measured data. [Work supported by NIH.
20. False recognition of instruction-set lures.
PubMed
Curtis, Evan T; Chubala, Chrissy M; Spear, Jackie; Jamieson, Randall K; Hockley, William E; Crump, Matthew J C
2016-01-01
False remembering has been examined using a variety of procedures, including the Deese-Roediger-McDermott procedure, the false fame procedure and the two-list recognition procedure. We present six experiments in a different empirical framework examining false recognition of words included in the experimental instructions (instruction-set lures). The data show that participants' false alarm rate to instruction-set lures was twice their false alarm rate to standard lures. That result was statistically robust even when (1) the relative strength of targets to instruction-set lures was increased, (2) participants were warned about the instruction-set lures, (3) the instruction-set lures were camouflaged in the study instructions and (4) the instruction-set lures were presented verbally at study but visually at test. False recognition of instruction-set lures was only mitigated when participants were distracted between encountering the instruction-set lures and studying the training list. The results confirm the ease with which recognition succumbs to familiarity and demonstrate the robustness of false recognition.
1. 21 CFR 1301.12 - Separate registrations for separate locations.
Code of Federal Regulations, 2010 CFR
2010-04-01
... location that will transfer controlled substances through the facility. The notice shall detail the registered locations that will utilize the facility, the location of the facility, the hours of operation... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Separate registrations for separate...
2. Justifying all the fuss about false belief.
PubMed
Russell, James
2005-07-01
The classic study by Wimmer and Perner showed that children below the age of about 4 years of age fail to appreciate others' false beliefs. This opened the floodgates to the theory-of-mind research programme. Recently, a study by Riggs and Simpson has called the central challenge of false belief into question, reporting similar difficulties with true belief. I would argue, however, that not only should the acquisition of false belief remain a central concern but that we should think harder about it and its earlier manifestations.
3. Stereoisomers Separation
Wieczorek, Piotr
The use of capillary electrophoresis for enantiomer separation and optical purity determination is presented. The contents start with basic information about the nature of stereoizomers and the mechanism of enantioseparation using capillary electrophoresis techniques. The molecules to be separated show identical chemical structure and electrochemical behavior. Therefore, the chiral recognition of enantiomers is possible only by bonding to chiral selector and the separation based on very small differences in complexation energies of diastereomer complexes formed. This method is useful for this purpose due to the fact that different compounds can be used as chiral selectors. The mostly used chiral selectors like cyclodextrins, crown ethers, chiral surfactants, macrocyclic antibiotics, transition metal complexes, natural, and synthetic polymers and their application for this purpose is also discussed. Finally, examples of practical applications of electromigration techniques for enantiomers separation and determination are presented.
4. Emotion and false memory: The context-content paradox.
PubMed
Bookbinder, S H; Brainerd, C J
2016-12-01
False memories are influenced by a variety of factors, but emotion is a variable of special significance, for theoretical and practical reasons. Interestingly, emotion's effects on false memory depend on whether it is embedded in the content of to-be-remembered events or in our moods, where mood is an aspect of the context in which events are encoded. We sketch the theoretical basis for this content-context dissociation and then review accumulated evidence that content and context effects are indeed different. Paradoxically, we find that in experiments on spontaneous and implanted false memories, negatively valenced content foments distortion, but negatively valenced moods protect against it. In addition, correlational data show that enduring negative natural moods (e.g., depression) foment false memory. Current opponent-process models of false memory, such as fuzzy-trace theory, are able to explain the content-context dissociation: Variations in emotional content primarily affect memory for the gist of events, whereas variations in emotional context primarily affect memory for events' exact verbatim form. Important questions remain about how these effects are modulated by variations in memory tests and in arousal. Promising methods of tackling those questions are outlined, especially designs that separate the gist and verbatim influences of emotion. (PsycINFO Database Record
5. Mist separator
SciTech Connect
Moran, T.M.
1984-04-17
An apparatus for the removal of particulates from a flowing gas stream and a process for its use are provided. A perforated screen separator formed as a plate having parallel rows of perforations formed by pushing alternating strips of the plate material forward and backward from the plane of the plate is used. The perforated screen separator may be used alone or with a fiber bed mist eliminator for increased particulate removal.
6. Visual false memories in posttraumatic stress disorder.
PubMed
Moradi, Ali Reza; Heydari, Ali Hosain; Abdollahi, Mohammad Hossain; Rahimi-Movaghar, Vafa; Dalgleish, Tim; Jobson, Laura
2015-11-01
This study investigated visual false memories in posttraumatic stress disorder (PTSD). The Scenic False Memory paradigm (SFM, Hauschildt, Peters, Jelinek, & Moritz, 2012) was administered to male Iranian military personnel who had participated in the Iran-Iraq war and were diagnosed with (n = 21) or without (n = 21) PTSD and a sample of healthy male non-trauma-exposed controls (n = 21). Trauma-exposed participants recalled and recognized a significantly lower percentage of hits and a significantly greater percentage of false memories for both trauma-related and non-trauma-related video scenes, than non-trauma-exposed controls. Among the trauma-exposed participants, those with and without PTSD did not differ significantly in terms of percentage of hits and false memories recalled on the SFM. Those with PTSD were found to recognize significantly fewer hits for both the trauma-related and non-trauma-related videos than those without PTSD. Those with PTSD also recognized significantly more false memories for the trauma video scene than the non-PTSD group. The findings suggest that those with trauma exposure, and in particular those with PTSD, may have a greater susceptibility to visual false memory.
7. Product separator
DOEpatents
Welsh, Robert A.; Deurbrouck, Albert W.
1976-01-20
A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.
8. 5 CFR 842.806 - Mandatory separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Mandatory separation. 842.806 Section 842... Traffic Controllers § 842.806 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C.... 2109(1)(B) (i.e., a second-level supervisor). A mandatory separation under 5 U.S.C. 8425 is not...
9. 24 CFR 3285.101 - Fire separation.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Fire separation. 3285.101 Section... separation. Fire separation distances must be in accordance with the requirements of Chapter 6 of NFPA 501A... installers to take into account any local requirements on fire separation....
10. 24 CFR 3285.101 - Fire separation.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Fire separation. 3285.101 Section... separation. Fire separation distances must be in accordance with the requirements of Chapter 6 of NFPA 501A... installers to take into account any local requirements on fire separation....
11. 5 CFR 842.806 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 842.806 Section 842... Traffic Controllers § 842.806 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C.... 2109(1)(B) (i.e., a second-level supervisor). A mandatory separation under 5 U.S.C. 8425 is not...
12. 5 CFR 842.806 - Mandatory separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Mandatory separation. 842.806 Section 842... Traffic Controllers § 842.806 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C.... 2109(1)(B) (i.e., a second-level supervisor). A mandatory separation under 5 U.S.C. 8425 is not...
13. 24 CFR 3285.101 - Fire separation.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Fire separation. 3285.101 Section... separation. Fire separation distances must be in accordance with the requirements of Chapter 6 of NFPA 501A... installers to take into account any local requirements on fire separation....
14. 5 CFR 842.806 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 842.806 Section 842... Traffic Controllers § 842.806 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C.... 2109(1)(B) (i.e., a second-level supervisor). A mandatory separation under 5 U.S.C. 8425 is not...
15. 24 CFR 3285.101 - Fire separation.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Fire separation. 3285.101 Section... separation. Fire separation distances must be in accordance with the requirements of Chapter 6 of NFPA 501A... installers to take into account any local requirements on fire separation....
16. 24 CFR 3285.101 - Fire separation.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Fire separation. 3285.101 Section... separation. Fire separation distances must be in accordance with the requirements of Chapter 6 of NFPA 501A... installers to take into account any local requirements on fire separation....
17. 5 CFR 842.806 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 842.806 Section 842... Traffic Controllers § 842.806 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C.... 2109(1)(B) (i.e., a second-level supervisor). A mandatory separation under 5 U.S.C. 8425 is not...
18. False Positive Mammograms and Detection Controlled Estimation
PubMed Central
Kleit, Andrew N; Ruiz, James F
2003-01-01
Objective To investigate the causes of false positive in mammograms. Data Sources Secondary data collected from extracts from computerized medical records from 1999 from five thousand patients at a single hospital in a medium-sized Southern city. Study Design Retrospective analysis of electronic medical data on screening and diagnostic mammograms. Detection-controlled estimation (DCE) was used to compare the efficacy of alternative readers of mammogram films. Analysis was also conducted on follow-up exams of women who tested positive in the first stage of investigation. Key variables included whether the patient had had a prior mammogram, age of the patient, and identifiers for the individual physicians. Data Collection/Extraction Methods Hospital maintains electronic medical records (EMR) on all patients. Extracts were performed on this EMR system under the guidance of clinical expertise. Data were collected for all women who had mammograms in 1999. Random samples were employed for screening mammograms, and all data was used for diagnostic mammograms. Principal Findings Study results imply that access to a previous mammogram greatly reduces the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography. Were previous mammograms always available, the results imply the number of false positives would decrease by at least half. The results here also indicate that there is no reason to believe this decrease in false positive would be accompanied by an increase in the number of false negatives. Other attributes also affected the number of false positives. Mondays and Wednesdays appear to be more prone to false positives than the other days in the week. There is also some disparity in false positive outcomes among the five physicians studied. With respect to detection-controlled estimation, the results are mixed. With follow-up data, the DCE estimator appears to generate reasonable, robust
19. False Memories for Affective Information in Schizophrenia
PubMed Central
Fairfield, Beth; Altamura, Mario; Padalino, Flavia A.; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola
2016-01-01
Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p < 0.05) when remembering episodes with positive or negative outcomes. The effect of valence was apparent in the patient group. For example, it did not affect the production causal false memories (p > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved. PMID:27965600
20. False Memories for Affective Information in Schizophrenia.
PubMed
Fairfield, Beth; Altamura, Mario; Padalino, Flavia A; Balzotti, Angela; Di Domenico, Alberto; Mammarella, Nicola
2016-01-01
Studies have shown a direct link between memory for emotionally salient experiences and false memories. In particular, emotionally arousing material of negative and positive valence enhanced reality monitoring compared to neutral material since emotional stimuli can be encoded with more contextual details and thereby facilitate the distinction between presented and imagined stimuli. Individuals with schizophrenia appear to be impaired in both reality monitoring and memory for emotional experiences. However, the relationship between the emotionality of the to-be-remembered material and false memory occurrence has not yet been studied. In this study, 24 patients and 24 healthy adults completed a false memory task with everyday episodes composed of 12 photographs that depicted positive, negative, or neutral outcomes. Results showed how patients with schizophrenia made a higher number of false memories than normal controls (p < 0.05) when remembering episodes with positive or negative outcomes. The effect of valence was apparent in the patient group. For example, it did not affect the production causal false memories (p > 0.05) resulting from erroneous inferences but did interact with plausible, script consistent errors in patients (i.e., neutral episodes yielded a higher degree of errors than positive and negative episodes). Affective information reduces the probability of generating causal errors in healthy adults but not in patients suggesting that emotional memory impairments may contribute to deficits in reality monitoring in schizophrenia when affective information is involved.
1. Map Separates
USGS Publications Warehouse
,
2001-01-01
U.S. Geological Survey (USGS) topographic maps are printed using up to six colors (black, blue, green, red, brown, and purple). To prepare your own maps or artwork based on maps, you can order separate black-and-white film positives or negatives for any color printed on a USGS topographic map, or for one or more of the groups of related features printed in the same color on the map (such as drainage and drainage names from the blue plate.) In this document, examples are shown with appropriate ink color to illustrate the various separates. When purchased, separates are black-and-white film negatives or positives. After you receive a film separate or composite from the USGS, you can crop, enlarge or reduce, and edit to add or remove details to suit your special needs. For example, you can adapt the separates for making regional and local planning maps or for doing many kinds of studies or promotions by using the features you select and then printing them in colors of your choice.
2. Learning words from speakers with false beliefs.
PubMed
Papafragou, Anna; Fairchild, Sarah; Cohen, Matthew L; Friedberg, Carlyn
2016-06-21
During communication, hearers try to infer the speaker's intentions to be able to understand what the speaker means. Nevertheless, whether (and how early) preschoolers track their interlocutors' mental states is still a matter of debate. Furthermore, there is disagreement about how children's ability to consult a speaker's belief in communicative contexts relates to their ability to track someone's belief in non-communicative contexts. Here, we study young children's ability to successfully acquire a word from a speaker with a false belief; we also assess the same children's success on a traditional false belief attribution task. We show that the ability to consult the epistemic state of a speaker during word learning develops between the ages of three and five. We also show that false belief understanding in word-learning contexts proceeds similarly to standard belief-attribution contexts when the tasks are equated. Our data offer evidence for the development of mind-reading abilities during language acquisition.
3. FALSE MEMORY AND OBSESSIVE–COMPULSIVE SYMPTOMS
PubMed Central
Klumpp, Heide; Amir, Nader; Garfinkel, Sarah N.
2013-01-01
Background The memory deficit hypothesis has been used to explain the maintenance of repetitive behavior in individuals with obsessive–compulsive disorder, yet the majority of studies focusing on verbal memory show mixed results. These studies primarily evaluated memory accuracy via the inclusion or omission of previously encountered material, as opposed to false recognition (i.e., the inclusion of erroneous material). We evaluated false memories and memory processes in individuals with obsessive–compulsive washing symptoms (OC), individuals matched on depression and anxiety without OC symptoms (D/A), and in nonanxious individuals (NAC). Methods Twenty-eight OC, 28 D/A, and 29 NAC individuals read OC-threat relevant, positive, and neutral scenarios and then performed a recognition test. Erroneous recognition of words associated to encoded, but not previously viewed, scenarios were classified as false memories. To evaluate processes underlying memory, participants completed a modified remember/know task to examine whether the OC individuals differed from the other individuals in recollective clarity for false memories of OC-relevant (e.g., germs), positive (e.g., lottery), and neutral (e.g., bread) material. Results The OC individuals used “know” more than the D/A and NAC individuals for false memories of threat. For veridical memories, the OC individuals used “know” more than the NAC, but not, D/A individuals. Conclusions The greater reliance on “know” (i.e., feelings of familiarity) in general and false threat memories in particular in individuals with OC symptoms may add to feelings of uncertainty for threat-relevant material, which may contribute to compulsive behavior. PMID:18839404
4. ISOTOPE SEPARATORS
DOEpatents
Bacon, C.G.
1958-08-26
An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.
5. Isotope separation
DOEpatents
Bartlett, Rodney J.; Morrey, John R.
1978-01-01
A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated.
6. How do our brain hemispheres cooperate to avoid false memories?
PubMed
Bergert, Susanne
2013-02-01
Memories are not always as reliable as they may appear. The occurrence of false memories can be reduced, however, by enhancing the cooperation between the two brain hemispheres. Yet is the communication from left to right hemisphere as helpful as the information transfer from right to left? To address this question, 72 participants were asked to learn 16 word lists. Applying the Deese-Roediger-McDermott paradigm, the words in each list were associated with an unpresented prototype word. In the test condition, learned words and corresponding prototypes were presented along with non-associated new words, and participants were asked to indicate which of the words they recognized. Crucially, both study and test words were projected to only one hemisphere in order to stimulate each hemisphere separately. It was found that false recognitions occurred significantly less often when the right hemisphere studied and the left hemisphere recognized the stimuli. Moreover, only the right-to-left direction of interhemispheric communication reduced false memories significantly, whereas left-to-right exchange did not. Further analyses revealed that the observed reduction of false memories was not due to an enhanced discrimination sensitivity, but to a stricter response bias. Hence, the data suggest that interhemispheric cooperation does not improve the ability to tell old and new apart, but rather evokes a conservative response tendency. Future studies may narrow down in which cognitive processing steps interhemispheric interaction can change the response criterion.
7. Infants' Reasoning about Others' False Perceptions
ERIC Educational Resources Information Center
Song, Hyun-joo; Baillargeon, Renee
2008-01-01
Prior research suggests that children younger than age 3 or 4 do not understand that an agent may be deceived by an object's misleading appearance. The authors asked whether 14.5-month-olds would give evidence in a violation-of-expectation task that they understand that agents may form false perceptions. Infants first watched events in which an…
8. Development of the False-Memory Illusion
ERIC Educational Resources Information Center
Brainerd, C. J.; Forrest, T. J.; Karibian, D.; Reyna, V. F.
2006-01-01
The counterintuitive developmental trend in the Deese-Roediger-McDermott (DRM) illusion (that false-memory responses increase with age) was investigated in learning-disabled and nondisabled children from the 6- to 14-year-old age range. Fuzzy-trace theory predicts that because there are qualitative differences in how younger versus older children…
9. False Accusations of Nosocomial Sexual Abuse.
ERIC Educational Resources Information Center
Money, John
1992-01-01
Practitioners performing routine physical examination may be falsely accused of sexual abuse. Criminal justice system is incompatible with biomedical system of prevention. It is responsible for establishment of sexual abuse industry, practitioners of which have vested interest in maintaining status quo of sexual criminalization. They themselves…
10. Vendor cited for false PFC savings claim
SciTech Connect
Greenstein, I.
1983-08-29
A Cynex power factor controller (PFC) vendor claiming a 60% saving was cited by the Better Business Bureau for false advertising after a user survey revealed that savings were only 20% at best. The company plans no future advertising claims, although it insists that 60% savings are possible. The inventor disagrees. (DCK)
11. How to Justify Teaching False Science
ERIC Educational Resources Information Center
Slater, Matthew H.
2008-01-01
We often knowingly teach false science. Such a practice conflicts with a prima facie pedagogical value placed on teaching only what is true. I argue that only a partial dissolution of the conflict is possible: the proper aim of instruction in science is not to provide an armory of facts about what things the world contains, how they interact, and…
12. Memory distrust syndrome, confabulation and false confession.
PubMed
Gudjonsson, Gisli
2017-02-01
There are three types of false confessions: 'voluntary', 'pressured-compliant' and 'pressured-internalized'. On the basis of case studies, in the early 1980s Gudjonsson and MacKeith coined the term 'memory distrust syndrome (MDS)' to describe a condition where people develop profound distrust of their memory and become susceptible to relying on external cues and suggestions from others. Memory distrust can, under certain circumstances, lead to a false confession, particularly of the pressured-internalized type, described as 'confabulation'. This article reviews the evidence for the condition and the psychological mechanism and processes involved. A heuristic model is then presented of a 32 year old man who falsely confessed to murder whilst in police custody. The key elements of the model involve the impact of 'contextual risk factors' (i.e., isolation, long and persistent guilt presumptive interrogation, and high emotional intensity) on 'enduring' vulnerability and 'acute state' factors. The detainee had kept a detailed diary whilst in solitary confinement that provided a unique insight into the gradual development of a MDS, his mental state, and thinking process. This type of false confession is apparently quite rare, but it can occur in intellectually able and educated individuals and involves 'delayed' rather than 'immediate' suggestibility.
13. Analysis of False Starts in Spontaneous Speech.
ERIC Educational Resources Information Center
O'Shaughnessy, Douglas
A primary difference between spontaneous speech and read speech concerns the use of false starts, where a speaker interrupts the flow of speech to restart his or her utterance. A study examined the acoustic aspects of such restarts in a widely-used speech database, examining approximately 1000 utterances, about 10% of which contained a restart.…
14. Underpowered samples, false negatives, and unconscious learning.
PubMed
Vadillo, Miguel A; Konstantinidis, Emmanouil; Shanks, David R
2016-02-01
The scientific community has witnessed growing concern about the high rate of false positives and unreliable results within the psychological literature, but the harmful impact of false negatives has been largely ignored. False negatives are particularly concerning in research areas where demonstrating the absence of an effect is crucial, such as studies of unconscious or implicit processing. Research on implicit processes seeks evidence of above-chance performance on some implicit behavioral measure at the same time as chance-level performance (that is, a null result) on an explicit measure of awareness. A systematic review of 73 studies of contextual cuing, a popular implicit learning paradigm, involving 181 statistical analyses of awareness tests, reveals how underpowered studies can lead to failure to reject a false null hypothesis. Among the studies that reported sufficient information, the meta-analytic effect size across awareness tests was d z = 0.31 (95 % CI 0.24-0.37), showing that participants' learning in these experiments was conscious. The unusually large number of positive results in this literature cannot be explained by selective publication. Instead, our analyses demonstrate that these tests are typically insensitive and underpowered to detect medium to small, but true, effects in awareness tests. These findings challenge a widespread and theoretically important claim about the extent of unconscious human cognition.
15. A Synchronization Account of False Recognition
ERIC Educational Resources Information Center
Johns, Brendan T.; Jones, Michael N.; Mewhort, Douglas J. K.
2012-01-01
We describe a computational model to explain a variety of results in both standard and false recognition. A key attribute of the model is that it uses plausible semantic representations for words, built through exposure to a linguistic corpus. A study list is encoded in the model as a gist trace, similar to the proposal of fuzzy trace theory…
16. SEPARATION PROCESS
DOEpatents
Stoughton, R.W.
1961-10-24
A process for separating tetravalent plutonium from aqueous solutions and from niobium and zirconium by precipitation on lanthanum oxalate is described. The oxalate ions of the precipitate may be decomposed by heating in the presence of an oxidizing agent, forming a plutonium compound readily soluble in acid. (AEC)
17. Plasma separation
NASA Technical Reports Server (NTRS)
Steurer, Wolfgang
1992-01-01
This process employs a thermal plasma for the separation and production of oxygen and metals. It is a continuous process that requires no consumables and relies entirely on space resources. The almost complete absence of waste renders it relatively clean. It can be turned on or off without any undesirable side effects or residues. The prime disadvantage is its high power consumption.
18. False positive reduction for lung nodule CAD
Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.
2007-03-01
Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.
19. False alarm reduction in critical care.
PubMed
Clifford, Gari D; Silva, Ikaro; Moody, Benjamin; Li, Qiao; Kella, Danesh; Chahin, Abdullah; Kooistra, Tristan; Perry, Diane; Mark, Roger G
2016-08-01
High false alarm rates in the ICU decrease quality of care by slowing staff response times while increasing patient delirium through noise pollution. The 2015 PhysioNet/Computing in Cardiology Challenge provides a set of 1250 multi-parameter ICU data segments associated with critical arrhythmia alarms, and challenges the general research community to address the issue of false alarm suppression using all available signals. Each data segment was 5 minutes long (for real time analysis), ending at the time of the alarm. For retrospective analysis, we provided a further 30 seconds of data after the alarm was triggered. A total of 750 data segments were made available for training and 500 were held back for testing. Each alarm was reviewed by expert annotators, at least two of whom agreed that the alarm was either true or false. Challenge participants were invited to submit a complete, working algorithm to distinguish true from false alarms, and received a score based on their program's performance on the hidden test set. This score was based on the percentage of alarms correct, but with a penalty that weights the suppression of true alarms five times more heavily than acceptance of false alarms. We provided three example entries based on well-known, open source signal processing algorithms, to serve as a basis for comparison and as a starting point for participants to develop their own code. A total of 38 teams submitted a total of 215 entries in this year's Challenge. This editorial reviews the background issues for this challenge, the design of the challenge itself, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. Additionally we make some recommendations for future changes in the field of patient monitoring as a result of the Challenge.
20. False Belief vs. False Photographs: A Test of Theory of Mind or Working Memory?
PubMed
Callejas, Alicia; Shulman, Gordon L; Corbetta, Maurizio
2011-01-01
Theory of mind (ToM), the ability to reason about other people's thoughts and beliefs, has been traditionally studied in behavioral and neuroimaging experiments by comparing performance in "false belief" and "false photograph" (control) stories. However, some evidence suggests that these stories are not matched in difficulty, complicating the interpretation of results. Here, we more fully evaluated the relative difficulty of comprehending these stories and drawing inferences from them. Subjects read false belief and false photograph stories followed by comprehension questions that probed true ("reality" questions) or false beliefs ("representation" questions) appropriate to the stories. Stories and comprehension questions were read and answered, respectively, more slowly in the false photograph than false belief conditions, indicating their greater difficulty. Interestingly, accuracy on representation questions for false photograph stories was significantly lower than for all other conditions and correlated positively with participants' working memory span scores. These results suggest that drawing representational inferences from false photo stories is particularly difficult and places heavy demands on working memory. Extensive naturalistic practice with ToM reasoning may enable a more flexible and efficient mental representation of false belief stories, resulting in lower memory load requirements. An important implication of these results is that the differential modulation of right temporal-parietal junction (RTPJ) during ToM and "false photo" control conditions may reflect the documented negative correlation of RTPJ activity with working memory load rather than a specialized involvement in ToM processes.
1. Trade-off between false positives and false negatives in the linkage analysis of complex traits.
PubMed
Todorov, A A; Rao, D C
1997-01-01
This study examines the issue of false positives in genomic scans for detecting complex trait loci using subpair linkage methods and investigates the trade-off between the rate of false positives and the rate of false negatives. It highlights the tremendous cost in terms of power brought about by an excessive control of type I error and, at the same time, confirms that a larger number of false positives can occur otherwise in the course of a genomic scan. Finally, it compares the power and rate of false positives obtained in preplanned replicated studies conducted using a liberal significance level to those for single-step studies that use the same total sample size but stricter levels of significance. For the models considered here, replicate studies were found more attractive as long as one is willing to accept a trade-off, exchanging a much lower rate of false negatives for a slight increase in the rate of false positives.
2. The problem with false vacuum Higgs inflation
Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert
2014-06-01
We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios.
3. Accounting for false negatives in hotspot detection
SciTech Connect
Sego, Landon H.; Wilson, John E.
2007-08-28
Hotspot sampling designs are used in environmental sampling to identify the location of one (or more) contiguous regions of elevated contamination. These regions are known as hotspots. The problem of how to calculate the probability of detecting an elliptical hotspot using a rectangular or triangular grid of sampling points was addressed by Singer and Wickman in 1969. This approach presumed that any sample which coincided with a hotspot would detect the hotspot without error. However, for many sampling methodologies, there is a chance that the hotspot will not be detected even though it has been sampled directly--a false negative. We present a mathematical solution and a numerical algorithm which account for false negatives when calculating the probability of detecting hotspots that are circular in shape.
4. Cosmic chirality both true and false.
PubMed
Barron, Laurence D
2012-12-01
The discrete symmetries of parity P, time reversal T, and charge conjugation C may be used to characterize the properties of chiral systems. It is well known that parity violation infiltrates into ordinary matter via an interaction between the nucleons and electrons, mediated by the Z(0) particle, that lifts the degeneracy of the mirror-image enantiomers of a chiral molecule. Being odd under P but even under T, this P-violating interaction exhibits true chirality and so may induce absolute enantioselection under all circumstances. It has been suggested that CP violation may also infiltrate into ordinary matter via a P-odd, T-odd interaction mediated by the (as yet undetected) axion. This CP-violating interaction exhibits false chirality and so may induce absolute enantioselection in processes far from equilibrium. Both true and false cosmic chirality should be considered together as possible sources of homochirality in the molecules of life.
5. Spirit Beholds Bumpy Boulder (False Color)
NASA Technical Reports Server (NTRS)
2006-01-01
As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of 'Low Ridge.' The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.
Spirit took this false-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006). This image is a false-color rendering using camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.
6. Constrained potential method for false vacuum decays
SciTech Connect
Park, Jae-hyeon
2011-02-01
A procedure is reported for numerical analysis of false vacuum transition in a model with multiple scalar fields. It is a refined version of the approach by Konstandin and Huber. The alteration makes it possible to tackle a class of problems that was difficult or unsolvable with the original method, i.e. those with a distant or nonexistent true vacuum. An example with an unbounded-from-below direction is presented.
7. False Context Fear Memory in Rats
ERIC Educational Resources Information Center
Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick
2015-01-01
Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…
8. Gas separating
DOEpatents
Gollan, Arye Z.
1990-12-25
Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.
9. Gas separating
DOEpatents
Gollan, Arye
1988-01-01
Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.
10. Dust separator
SciTech Connect
Borow, H.
1987-01-27
This patent describes a gas filter apparatus for separating solids from a gas stream comprising a housing having a top, base, and side walls defining a chamber, a partition wall extending across the chamber and separating the chamber into an upper compartment and a lower compartment. A gas inlet conveyor tube in the chamber passes downwardly of the partition and into the lower compartment, the portion of the conveyor tube passing through the upper compartment being impervious and the portion of the conveyor tube extending downwardly into the lower compartment being provided with exit means including exit apertures at least in the area of the conveyor tube adjacent the partition wall. The partition wall is provided with openings surrounding the conveyor tube and communicates the lower compartment with the upper compartment. A filter means in the form of filter tubes covers each opening in the partition wall and extends downwardly in the lower compartment and parallel to the conveyor tube, at least one gas outlet communicating with the upper compartment. A suction means is associated with the gas outlet to provide a reduced pressure within the chamber. A discharge means at the base of the housing is associated with the lower compartment for discharging solid matter separated from the gas stream. The solid laden gas is conveyed into the lower compartment downwardly by the conveying tube and the gas of the stream is drawn from the conveyor tube immediately past the partition, through the surrounding filter tubes in order to prevent the formation of counter gas flows to the gravity discharge of the solids being separated from the gas stream.
11. False memories in Lewy-body disease.
PubMed
Algarabel, Salvador; Pitarque, Alfonso; Sales, Alicia; Meléndez, Juan Carlos; Escudero, Joaquín
2015-12-01
Recently, de Boysson, Belleville, Phillips et al. (2011) found that patients with Lewy-body disease (LBD) showed significantly lower rates of false memories than healthy controls, using the Deese-Roediger-McDermott (DRM) experimental procedure. Given that this result could be explained by the practically null rate of true recognition in the LBD group (0.09), we decided to replicate the study by de Boysson et al. (2011), but including a new condition that would maximize the true recognition rate (and analyze its effect on the rate of false memories). Specifically, in a DRM experiment, we manipulated (within subjects) two study and recognition conditions: in the "immediate" condition, both the LBD patients and the control group of healthy older people received a different recognition test after each study list (containing twelve words associated with a non-presented critical word), while in the "delayed" condition (similar to the one in de Boysson et al., 2011), the participants received the entire series of study lists and then took only one recognition test. The results showed that, in both samples, the "immediate" condition produced higher corrected rates of both true and false recognition than the "delayed" condition, although they were both lower in the LBD patients, which shows that these patients are capable of encoding and recognizing the general similitude underlying information (gist memory) in the right conditions.
12. Infants’ Reasoning About Others’ False Perceptions
PubMed Central
Song, Hyun-joo; Baillargeon, Renée
2012-01-01
Prior research suggests that children younger than age 3 or 4 do not understand that an agent may be deceived by an object’s misleading appearance. The authors asked whether 14.5-month-olds would give evidence in a violation-of-expectation task that they understand that agents may form false perceptions. Infants first watched events in which an agent faced a stuffed skunk and a doll with blue pigtails; the agent consistently reached for the doll, suggesting that she preferred it over the skunk. Next, while the agent was absent, the doll was hidden in a plain box, and the skunk was hidden in a box with a tuft of blue hair protruding from under its lid. Infants expected the agent to be misled by the tuft’s resemblance to the doll’s hair and to falsely perceive it as belonging to the doll. These and other results indicate that 14.5-month-old infants can already reason about agents’ false perceptions. PMID:18999340
13. False Beliefs in Unreliable Knowledge Networks
Ioannidis, Evangelos; Varsakelis, Nikos; Antoniou, Ioannis
2017-03-01
The aims of this work are: (1) to extend knowledge dynamics analysis in order to assess the influence of false beliefs and unreliable communication channels, (2) to investigate the impact of selection rule-policy for knowledge acquisition, (3) to investigate the impact of targeted link attacks ("breaks" or "infections") of certain "healthy" communication channels. We examine the knowledge dynamics analytically, as well as by simulations on both artificial and real organizational knowledge networks. The main findings are: (1) False beliefs have no significant influence on knowledge dynamics, while unreliable communication channels result in non-monotonic knowledge updates ("wild" knowledge fluctuations may appear) and in significant elongation of knowledge attainment. Moreover, false beliefs may emerge during knowledge evolution, due to the presence of unreliable communication channels, even if they were not present initially, (2) Changing the selection rule-policy, by raising the awareness of agents to avoid the selection of unreliable communication channels, results in monotonic knowledge upgrade and in faster knowledge attainment, (3) "Infecting" links is more harmful than "breaking" links, due to "wild" knowledge fluctuations and due to the elongation of knowledge attainment. Moreover, attacking even a "small" percentage of links (≤5%) with high knowledge transfer, may result in dramatic elongation of knowledge attainment (over 100%), as well as in delays of the onset of knowledge attainment. Hence, links of high knowledge transfer should be protected, because in Information Warfare and Disinformation, these links are the "best targets".
14. Separation system
DOEpatents
Rubin, Leslie S.
1986-01-01
A separation system for dewatering radioactive waste materials includes a disposal container, drive structure for receiving the container, and means for releasably attaching the container to the drive structure. Separation structure disposed in the container adjacent the inner surface of the side wall structure retains solids while allowing passage of liquids. Inlet port structure in the container top wall is normally closed by first valve structure that is centrifugally actuated to open the inlet port and discharge port structure at the container periphery receives liquid that passes through the separation structure and is normally closed by second valve structure that is centrifugally actuated to open the discharge ports. The container also includes coupling structure for releasable engagement with the centrifugal drive structure. Centrifugal force produced when the container is driven in rotation by the drive structure opens the valve structures, and radioactive waste material introduced into the container through the open inlet port is dewatered, and the waste is compacted. The ports are automatically closed by the valves when the container drum is not subjected to centrifugal force such that containment effectiveness is enhanced and exposure of personnel to radioactive materials is minimized.
15. A closer look at self-reported suicide attempts: false positives and false negatives.
PubMed
Plöderl, Martin; Kralovec, Karl; Yazdi, Kurosch; Fartacek, Reinhold
2011-02-01
The validity of self-reported suicide attempt information is undermined by false positives (e.g., incidences without intent to die), or by unreported suicide attempts, referred to as false negatives. In a sample of 1,385 Austrian adults, we explored the occurrence of false positives and false negatives with detailed, probing questions. Removing false positives decreased the rate of suicide attempters from 4.3% to 2.7%. Probing questions also revealed 0.8% false negatives. We recommend using probing questions with both those who report a suicide attempt and those who do not report a suicide attempt to increase the validity of self-reported suicide-related information.
16. False negative clinical diagnoses of malignant melanoma.
PubMed
Osborne, J E; Bourke, J F; Graham-Brown, R A; Hutchinson, P E
1999-05-01
The false negative rate for the clinical diagnosis (FNR) for malignant melanoma is reported to be of the order of 20-50%. The aim of this study was to investigate possible predictor variables for FNR, with particular reference to the features and score of the seven-point check-list within the total population (778) of histologically proved malignant melanomas presenting in Leicestershire between 1982 and 1996. The FNR was 18.5%. The check-list would have failed as a referral indication in only 0.8-1. 1% of the lesions. The major check-list features occurred more commonly than the minor features, excepting size >/= 7 mm, confirming the diagnostic importance of the major criteria. The FNR was unaffected by age or sex. More rarely involved sites had higher rates (31-42%), and the face was a particularly difficult diagnostic site. Clinical features of lesions associated with a higher FNR were lack of irregular pigmentation and shape, altered sensation, the presence of inflammation and size < 7 mm. The FNR was inversely related to the total score and major feature score, but directly related to the minor score. The minor features, in addition to the major features, are potentially valuable in avoiding false negative diagnoses and we suggest their retention as part of the check-list. There was only one patient, in whom the diagnosis of melanoma was initially missed and who was not biopsied on presentation to hospital, who re-presented after 1 year. However, the study illustrates the importance of avoiding a false negative diagnosis as there was marked delay in the excision of such lesions.
17. Uranus in True and False Color
NASA Technical Reports Server (NTRS)
1986-01-01
These two pictures of Uranus -- one in true color (left) and the other in false color -- were compiled from images returned Jan. 17, 1986, by the narrow-angle camera of Voyager 2. The spacecraft was 9.1 million kilometers (5.7 million miles) from the planet, several days from closest approach. The picture at left has been processed to show Uranus as human eyes would see it from the vantage point of the spacecraft. The picture is a composite of images taken through blue, green and orange filters. The darker shadings at the upper right of the disk correspond to the day-night boundary on the planet. Beyond this boundary lies the hidden northern hemisphere of Uranus, which currently remains in total darkness as the planet rotates. The blue-green color results from the absorption of red light by methane gas in Uranus' deep, cold and remarkably clear atmosphere. The picture at right uses false color and extreme contrast enhancement to bring out subtle details in the polar region of Uranus. Images obtained through ultraviolet, violet and orange filters were respectively converted to the same blue, green and red colors used to produce the picture at left. The very slight contrasts visible in true color are greatly exaggerated here. In this false-color picture, Uranus reveals a dark polar hood surrounded by a series of progressively lighter concentric bands. One possible explanation is that a brownish haze or smog, concentrated over the pole, is arranged into bands by zonal motions of the upper atmosphere. The bright orange and yellow strip at the lower edge of the planet's limb is an artifact of the image enhancement. In fact, the limb is dark and uniform in color around the planet. The Voyager project is manages for NASA by the Jet Propulsion Laboratory.
18. False discovery rates in spectral identification.
PubMed
Jeong, Kyowon; Kim, Sangtae; Bandeira, Nuno
2012-01-01
Automated database search engines are one of the fundamental engines of high-throughput proteomics enabling daily identifications of hundreds of thousands of peptides and proteins from tandem mass (MS/MS) spectrometry data. Nevertheless, this automation also makes it humanly impossible to manually validate the vast lists of resulting identifications from such high-throughput searches. This challenge is usually addressed by using a Target-Decoy Approach (TDA) to impose an empirical False Discovery Rate (FDR) at a pre-determined threshold x% with the expectation that at most x% of the returned identifications would be false positives. But despite the fundamental importance of FDR estimates in ensuring the utility of large lists of identifications, there is surprisingly little consensus on exactly how TDA should be applied to minimize the chances of biased FDR estimates. In fact, since less rigorous TDA/FDR estimates tend to result in more identifications (at higher 'true' FDR), there is often little incentive to enforce strict TDA/FDR procedures in studies where the major metric of success is the size of the list of identifications and there are no follow up studies imposing hard cost constraints on the number of reported false positives. Here we address the problem of the accuracy of TDA estimates of empirical FDR. Using MS/MS spectra from samples where we were able to define a factual FDR estimator of 'true' FDR we evaluate several popular variants of the TDA procedure in a variety of database search contexts. We show that the fraction of false identifications can sometimes be over 10× higher than reported and may be unavoidably high for certain types of searches. In addition, we further report that the two-pass search strategy seems the most promising database search strategy. While unavoidably constrained by the particulars of any specific evaluation dataset, our observations support a series of recommendations towards maximizing the number of resulting
19. Gas separating
DOEpatents
Gollan, A.
1988-03-29
Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.
20. Gas separating
DOEpatents
Gollan, A.Z.
1990-12-25
Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.
1. Maltreatment increases spontaneous false memories but decreases suggestion-induced false memories in children.
PubMed
Otgaar, Henry; Howe, Mark L; Muris, Peter
2017-01-17
We examined the creation of spontaneous and suggestion-induced false memories in maltreated and non-maltreated children. Maltreated and non-maltreated children were involved in a Deese-Roediger-McDermott false memory paradigm where they studied and remembered negative and neutral word lists. Suggestion-induced false memories were created using a misinformation procedure during which both maltreated and non-maltreated children viewed a negative video (i.e., bank robbery) and later received suggestive misinformation concerning the event. Our results showed that maltreated children had higher levels of spontaneous negative false memories but lower levels of suggestion-induced false memories as compared to non-maltreated children. Collectively, our study demonstrates that maltreatment both increases and decreases susceptibility to memory illusions depending on the type of false memory being induced. Statement of contribution What is already known on this subject? Trauma affects memory. It is unclear how trauma affects false memory. What does this study add? This study focuses on two types of false memories.
2. On False-Positive and False-Negative Decisions with a Mastery Test.
ERIC Educational Resources Information Center
Wilcox, Rand R.
Wilcox (1977) examines two methods of estimating the probability of a false-positive on false-negative decision with a mastery test. Both procedures make assumptions about the form of the true score distribution which might not give good results in all situations. In this paper, upper and lower bounds on the two possible error types are described…
3. Improved False Discovery Rate Estimation Procedure for Shotgun Proteomics
PubMed Central
2016-01-01
Interpreting the potentially vast number of hypotheses generated by a shotgun proteomics experiment requires a valid and accurate procedure for assigning statistical confidence estimates to identified tandem mass spectra. Despite the crucial role such procedures play in most high-throughput proteomics experiments, the scientific literature has not reached a consensus about the best confidence estimation methodology. In this work, we evaluate, using theoretical and empirical analysis, four previously proposed protocols for estimating the false discovery rate (FDR) associated with a set of identified tandem mass spectra: two variants of the target-decoy competition protocol (TDC) of Elias and Gygi and two variants of the separate target-decoy search protocol of Käll et al. Our analysis reveals significant biases in the two separate target-decoy search protocols. Moreover, the one TDC protocol that provides an unbiased FDR estimate among the target PSMs does so at the cost of forfeiting a random subset of high-scoring spectrum identifications. We therefore propose the mix-max procedure to provide unbiased, accurate FDR estimates in the presence of well-calibrated scores. The method avoids biases associated with the two separate target-decoy search protocols and also avoids the propensity for target-decoy competition to discard a random subset of high-scoring target identifications. PMID:26152888
4. False alarm reduction during landmine detection
Prado, P. J.; Chongpison, A.; Doraisamy, L.
2007-04-01
Quadrupole Resonance sensors have the unique capability of detecting explosives from buried, plastic-cased antipersonnel and antitank landmines. The chemical specificity of this radio-frequency technique provides the potential to deliver remarkably low false alarm rates during landmine detection. This is of particular importance to deminers, who frequently come across numerous clutter items before uncovering a mine. Quadrupole Resonance is typically utilized in a confirmation mode; preceded by rapid primary scans carried out by, for example, metal detectors, ground penetrating radars or a fusion of these. Significant technical and scientific advances have resulted in the fabrication of handheld and vehicle mounted Quadrupole Resonance landmine detectors in compact, power-efficient configurations. The development work is focused on baseline sensitivity increase, as well as the achievement of high detection performance under field conditions. The mine detection capability of Quadrupole Resonance detectors has been evaluated during various blind tests. A modular handheld unit, combining primary and confirmation sensors, was designed to be operated by a single person. A series of field tests demonstrate the unique capability of Quadrupole Resonance for significant false alarm reduction.
5. 5 CFR 831.808 - Mandatory separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Mandatory separation. 831.808 Section 831... (CONTINUED) RETIREMENT Nuclear Materials Couriers § 831.808 Mandatory separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8335(b) apply to all nuclear...
6. 7 CFR 201.47 - Separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 3 2012-01-01 2012-01-01 false Separation. 201.47 Section 201.47 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.47 Separation. (a) The working sample shall... weigh the similar kinds or varieties together as one component and make the separation on a...
7. 7 CFR 201.47 - Separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 3 2013-01-01 2013-01-01 false Separation. 201.47 Section 201.47 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.47 Separation. (a) The working sample shall... weigh the similar kinds or varieties together as one component and make the separation on a...
8. 5 CFR 831.908 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 831.908 Section 831... (CONTINUED) RETIREMENT Law Enforcement Officers and Firefighters § 831.908 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C. 8335(b) apply to all law enforcement officers and...
9. 5 CFR 831.808 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 831.808 Section 831... (CONTINUED) RETIREMENT Nuclear Materials Couriers § 831.808 Mandatory separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8335(b) apply to all nuclear...
10. 5 CFR 842.908 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 842.908 Section 842... separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8425 apply to all nuclear materials couriers including those in secondary positions. A mandatory...
11. 5 CFR 842.1006 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 842.1006 Section....1006 Mandatory separation. (a) Except as provided in paragraph (d) of this section, the mandatory separation provisions of 5 U.S.C. 8425 apply to customs and border protection officers, including those...
12. 7 CFR 201.47 - Separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 3 2014-01-01 2014-01-01 false Separation. 201.47 Section 201.47 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.47 Separation. (a) The working sample shall... weigh the similar kinds or varieties together as one component and make the separation on a...
13. 5 CFR 842.908 - Mandatory separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Mandatory separation. 842.908 Section 842... separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8425 apply to all nuclear materials couriers including those in secondary positions. A mandatory...
14. 5 CFR 831.908 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 831.908 Section 831... (CONTINUED) RETIREMENT Law Enforcement Officers and Firefighters § 831.908 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C. 8335(b) apply to all law enforcement officers and...
15. 5 CFR 831.908 - Mandatory separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Mandatory separation. 831.908 Section 831... (CONTINUED) RETIREMENT Law Enforcement Officers and Firefighters § 831.908 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C. 8335(b) apply to all law enforcement officers and...
16. 5 CFR 831.808 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 831.808 Section 831... (CONTINUED) RETIREMENT Nuclear Materials Couriers § 831.808 Mandatory separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8335(b) apply to all nuclear...
17. 5 CFR 831.1608 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 831.1608 Section... (CONTINUED) RETIREMENT Customs and Border Protection Officers § 831.1608 Mandatory separation. (a) Except as provided in paragraph (c) of this section, the mandatory separation provisions of 5 U.S.C. 8335(b) apply...
18. 5 CFR 842.1006 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 842.1006 Section....1006 Mandatory separation. (a) Except as provided in paragraph (d) of this section, the mandatory separation provisions of 5 U.S.C. 8425 apply to customs and border protection officers, including those...
19. 5 CFR 831.908 - Mandatory separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Mandatory separation. 831.908 Section 831... (CONTINUED) RETIREMENT Law Enforcement Officers and Firefighters § 831.908 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C. 8335(b) apply to all law enforcement officers and...
20. 5 CFR 842.908 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 842.908 Section 842... separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8425 apply to all nuclear materials couriers including those in secondary positions. A mandatory...
1. 5 CFR 842.908 - Mandatory separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Mandatory separation. 842.908 Section 842... separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8425 apply to all nuclear materials couriers including those in secondary positions. A mandatory...
2. 5 CFR 831.1608 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 831.1608 Section... (CONTINUED) RETIREMENT Customs and Border Protection Officers § 831.1608 Mandatory separation. (a) Except as provided in paragraph (c) of this section, the mandatory separation provisions of 5 U.S.C. 8335(b) apply...
3. 7 CFR 201.47 - Separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 3 2011-01-01 2011-01-01 false Separation. 201.47 Section 201.47 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.47 Separation. (a) The working sample shall... weigh the similar kinds or varieties together as one component and make the separation on a...
4. 7 CFR 201.47 - Separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 3 2010-01-01 2010-01-01 false Separation. 201.47 Section 201.47 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.47 Separation. (a) The working sample shall... weigh the similar kinds or varieties together as one component and make the separation on a...
5. 5 CFR 831.808 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 831.808 Section 831... (CONTINUED) RETIREMENT Nuclear Materials Couriers § 831.808 Mandatory separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8335(b) apply to all nuclear...
6. 5 CFR 831.908 - Mandatory separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Mandatory separation. 831.908 Section 831... (CONTINUED) RETIREMENT Law Enforcement Officers and Firefighters § 831.908 Mandatory separation. (a) The mandatory separation provisions of 5 U.S.C. 8335(b) apply to all law enforcement officers and...
7. 5 CFR 842.1006 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 842.1006 Section....1006 Mandatory separation. (a) Except as provided in paragraph (d) of this section, the mandatory separation provisions of 5 U.S.C. 8425 apply to customs and border protection officers, including those...
8. 5 CFR 831.808 - Mandatory separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Mandatory separation. 831.808 Section 831... (CONTINUED) RETIREMENT Nuclear Materials Couriers § 831.808 Mandatory separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8335(b) apply to all nuclear...
9. 5 CFR 842.908 - Mandatory separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Mandatory separation. 842.908 Section 842... separation. (a) Effective on and after October 17, 1999, the mandatory separation provisions of 5 U.S.C. 8425 apply to all nuclear materials couriers including those in secondary positions. A mandatory...
10. 5 CFR 831.1608 - Mandatory separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Mandatory separation. 831.1608 Section... (CONTINUED) RETIREMENT Customs and Border Protection Officers § 831.1608 Mandatory separation. (a) Except as provided in paragraph (c) of this section, the mandatory separation provisions of 5 U.S.C. 8335(b) apply...
11. Psychoactive drugs and false memory: comparison of dextroamphetamine and delta-9-tetrahydrocannabinol on false recognition
PubMed Central
Ballard, Michael E.; Gallo, David A.; de Wit, Harriet
2014-01-01
Rationale Several psychoactive drugs are known to influence episodic memory. However, these drugs’ effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood. Objectives Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Δ9-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger–McDermott (DRM) illusion. Methods Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions. Results As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs’ effects on true memory were positively correlated with their effects on false memory. Conclusions Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories. PMID:21647577
12. Two Holes in 'Wooly Patch' (False Color)
NASA Technical Reports Server (NTRS)
2004-01-01
The rock abrasion tool on NASA's Mars Exploration Rover Spirit ground two holes in a relatively soft rock called 'Wooly Patch' near the base of the 'Columbia Hills' inside Gusev Crater on Mars. This false-color image from the panoramic camera was taken on sol 200 (July 25, 2004) and generated using the camera's 750-, 530-, and 430-nanometer filters. It highlights the material ground up by the rock abrasion tool, grayish-blue in appearance in this image. The color of the material excavated suggests the interior of the rock contains iron minerals that are less oxidized than the dust or possibly weathered coating on the exterior of the rock. Scientists speculate that this relatively soft rock (compared to others analyzed by Spirit) may have been modified by water. Small cracks in the surface outside the drill holes may be the result of interactions with water-rich fluids.
13. Caffeine's effects on true and false memory.
PubMed
Capek, Sarah; Guenther, R Kim
2009-06-01
Caffeine's effects on recall of word lists were investigated using the Deese-Roediger-McDermott (DRM) paradigm. College students were administered either 200 mg of caffeine or a 250-mg lactose placebo; after 30 min., they were tested on recall using six word lists. Words of each list were semantically related to a single word (a "critical lure") that was not presented in the list. Participants administered caffeine recalled more list words and more critical lures than participants administered lactose. Recall of list words was negatively correlated with recall of critical lures. Caffeine appears to intensify the strength of connections among list words and critical lures, thereby enhancing both true and false memory.
14. Remembering, imagining, false memories & personal meanings.
PubMed
Conway, Martin A; Loveday, Catherine
2015-05-01
The Self-Memory System encompasses the working self, autobiographical memory and episodic memory. Specific autobiographical memories are patterns of activation over knowledge structures in autobiographical and episodic memory brought about by the activating effect of cues. The working self can elaborate cues based on the knowledge they initially activate and so control the construction of memories of the past and the future. It is proposed that such construction takes place in the remembering-imagining system - a window of highly accessible recent memories and simulations of near future events. How this malfunctions in various disorders is considered as are the implication of what we term the modern view of human memory for notions of memory accuracy. We show how all memories are to some degree false and that the main role of memories lies in generating personal meanings.
15. Controlling the false discoveries in LASSO.
PubMed
Huang, Hanwen
2017-02-09
The LASSO method estimates coefficients by minimizing the residual sum of squares plus a penalty term. The regularization parameter λ in LASSO controls the trade-off between data fitting and sparsity. We derive relationship between λ and the false discovery proportion (FDP) of LASSO estimator and show how to select λ so as to achieve a desired FDP. Our estimation is based on the asymptotic distribution of LASSO estimator in the limit of both sample size and dimension going to infinity with fixed ratio. We use a factor analysis model to describe the dependence structure of the design matrix. An efficient majorization-minimization based algorithm is developed to estimate the FDP at fixed value of λ. The analytic results are compared with those of numerical simulations on finite-size systems and are confirmed to be correct. An application to the high-throughput genomic riboavin data set also demonstrates the usefulness of our method.
16. Spirit Scans Winter Haven (False Color)
NASA Technical Reports Server (NTRS)
2006-01-01
At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand.
This view is a false-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.
17. Particle separator
DOEpatents
Hendricks, Charles D.
1990-01-01
Method and apparatus (10) are provided for separating and classifying particles (48,50,56) by dispersing the particles within a fluid (52) that is upwardly flowing within a cone-shaped pipe (12) that has its large end (20) above its small end (18). Particles of similar size and shape (48,50) migrate to individual levels (A,B) within the flowing fluid. As the fluid is deflected by a plate (42) at the top end of the pipe (12), the smallest particles are collected on a shelf-like flange (40). Ever larger particles are collected as the flow rate of the fluid is increased. To prevent particle sticking on the walls (14) of the pipe (12), additional fluid is caused to flow into the pipe (12) through holes (68) that are specifically provided for that purpose. Sticking is further prevented by high frequency vibrators (70) that are positioned on the apparatus (10).
18. Particle separation
DOEpatents
Moosmuller, Hans [Reno, NV; Chakrabarty, Rajan K [Reno, NV; Arnott, W Patrick [Reno, NV
2011-04-26
Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.
19. Particle separation
NASA Technical Reports Server (NTRS)
Moosmuller, Hans (Inventor); Chakrabarty, Rajan K. (Inventor); Arnott, W. Patrick (Inventor)
2011-01-01
Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.
20. Adaptive false memory: Imagining future scenarios increases false memories in the DRM paradigm.
PubMed
Dewhurst, Stephen A; Anderson, Rachel J; Grace, Lydia; van Esch, Lotte
2016-10-01
Previous research has shown that rating words for their relevance to a future scenario enhances memory for those words. The current study investigated the effect of future thinking on false memory using the Deese/Roediger-McDermott (DRM) procedure. In Experiment 1, participants rated words from 6 DRM lists for relevance to a past or future event (with or without planning) or in terms of pleasantness. In a surprise recall test, levels of correct recall did not vary between the rating tasks, but the future rating conditions led to significantly higher levels of false recall than the past and pleasantness conditions did. Experiment 2 found that future rating led to higher levels of false recognition than did past and pleasantness ratings but did not affect correct recognition. The effect in false recognition was, however, eliminated when DRM items were presented in random order. Participants in Experiment 3 were presented with both DRM lists and lists of unrelated words. Future rating increased levels of false recognition for DRM lures but did not affect correct recognition for DRM or unrelated lists. The findings are discussed in terms of the view that false memories can be associated with adaptive memory functions.
1. False discovery rates: a new deal
PubMed Central
2017-01-01
Summary We introduce a new Empirical Bayes approach for large-scale hypothesis testing, including estimating false discovery rates (FDRs), and effect sizes. This approach has two key differences from existing approaches to FDR analysis. First, it assumes that the distribution of the actual (unobserved) effects is unimodal, with a mode at 0. This “unimodal assumption” (UA), although natural in many contexts, is not usually incorporated into standard FDR analysis, and we demonstrate how incorporating it brings many benefits. Specifically, the UA facilitates efficient and robust computation—estimating the unimodal distribution involves solving a simple convex optimization problem—and enables more accurate inferences provided that it holds. Second, the method takes as its input two numbers for each test (an effect size estimate and corresponding standard error), rather than the one number usually used (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$p$\\end{document} value or \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$z$\\end{document} score). When available, using two numbers instead of one helps account for variation in measurement precision across tests. It also facilitates estimation of effects, and unlike standard FDR methods, our approach provides interval estimates (credible regions) for each effect in addition to measures of significance. To provide a bridge between interval estimates and significance measures, we introduce the term “local false sign rate” to refer to the probability of getting the sign of an effect wrong and argue that it is a superior
2. Allergen immunotherapy and allergic rhinitis: false beliefs
PubMed Central
2013-01-01
Background Over the last 100 years, several persistent misconceptions or ‘false beliefs’ have built up around allergen immunotherapy and its use in allergic rhinitis. This is perhaps because enthusiastic physicians administered complex allergen extracts to a diverse population of patients suffering from heterogeneous atopic conditions. Here, we review evidence that counters seven of these ‘false beliefs.’ Discussion 1. The symptoms of allergic rhinitis can be more heterogeneous, more severe and more troublesome in everyday life than many physicians believe. Large-scale epidemiological surveys show that the majority of allergic rhinitis patients have at least one symptom severe enough to interfere with sleep quality, productivity and/or well-being. 2. Allergen immunotherapy is not necessarily suitable for all allergic rhinitis patients (notably those with mild symptoms). Recent evidence from double-blind, placebo-controlled, randomized clinical trials suggests that the more severe the disease, the greater the treatment effect. 3. Allergen immunotherapy is often accused of lack of efficacy (relative to pharmacotherapy, for example). However, there are now many meta-analyses, systematic reviews and high-quality clinical trials that find overwhelmingly in favor of the efficacy of allergen immunotherapy (including sublingual formulations) in allergic rhinitis induced by pollen and, increasingly, other allergens. 4. Natural-exposure and challenge-chamber trials have shown that symptom relief may become apparent within months or even weeks of the initiation of allergen immunotherapy. 5. In pollen-induced allergic rhinitis, several years of subcutaneous or sublingual allergen immunotherapy are associated with sustained clinical efficacy after subsequent treatment cessation – confirming the disease-modifying nature of this therapy. 6. Most patients seeking treatment for allergic rhinitis are polysensitized, and allergen immunotherapy has proven efficacy in large
3. 'Endurance Crater's' Dazzling Dunes (false-color)
NASA Technical Reports Server (NTRS)
2004-01-01
As NASA's Mars Exploration Rover Opportunity creeps farther into 'Endurance Crater,' the dune field on the crater floor appears even more dramatic. This false-color image taken by the rover's panoramic camera shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a 'blue' tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules ('blueberries') that accumulate on the flat surfaces.
Sinuous tendrils of sand less than 1 meter (3.3 feet) high extend from the main dune field toward the rover. Scientists hope to send the rover down to one of these tendrils in an effort to learn more about the characteristics of the dunes. Dunes are a common feature across the surface of Mars, and knowledge gleaned from investigating the Endurance dunes close-up may apply to similar dunes elsewhere.
Before the rover heads down to the dunes, rover drivers must first establish whether the slippery slope that leads to them is firm enough to ensure a successful drive back out of the crater. Otherwise, such hazards might make the dune field a true sand trap.
4. False vacuum as an unstable state
Urbanowski, K.
2016-11-01
Calculations performed within the Standard Model suggest that the electroweak vacuum is unstable if MH < 126 GeV, (MH is the mass of the Higgs particle). LHC discovery of the Higgs boson indicates that MH ≃ 125 GeV. So the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory. At asymptotically late times the survival probability as a function of time t has an inverse power-like form. We show that at this time region the energy of the false vacuum states tends to the energy of the true vacuum state as 1/t2 for t → ∞. This means that the energy density in the unstable vacuum state should have analogous properties and hence the cosmological constant Λ = Λ(t) too. So Λ in the Universe with the unstable vacuum should have a form of the sum of the "bare" cosmological constant and of the term of a type 1/t^2:Λ (t) ≡ Λbare + d/t^2, (where Λbare is the cosmological constant for the Universe with the true vacuum).
5. Deep Hole in 'Clovis' (False Color)
NASA Technical Reports Server (NTRS)
2004-01-01
At a rock called 'Clovis,' the rock abrasion tool on NASA's Mars Exploration Rover Spirit cut a 9-millimeter (0.35-inch) hole during the rover's 216th martian day, or sol (Aug. 11, 2004). The hole is the deepest drilled in a rock on Mars so far. This false color view was made from images taken by Spirit's panoramic camera on sol 226 (Aug. 21, 2004) at around 12:50 p.m. local true solar time -- early afternoon in Gusev Crater on Mars. To the right is a 'brush flower' of circles produced by scrubbing the surface of the rock with the abrasion tool's wire brush. Scientists used rover's Moessbauer spectrometer and alpha particle X-ray spectrometer to look for iron-bearing minerals and determine the elemental chemical composition of the rock. This composite combines images taken with the camera's 750-, 530-, and 430-nanometer filters. The grayish-blue hue in this image suggests that the interior of the rock contains iron minerals that are less oxidized than minerals on the surface. The diameter of the hole cut into the rock is 4.5 centimeters (1.8 inches).
6. The False Security of Blind Dates
PubMed Central
Cimino, J.J.
2012-01-01
Background The reuse of clinical data for research purposes requires methods for the protection of personal privacy. One general approach is the removal of personal identifiers from the data. A frequent part of this anonymization process is the removal of times and dates, which we refer to as “chrononymization.” While this step can make the association with identified data (such as public information or a small sample of patient information) more difficult, it comes at a cost to the usefulness of the data for research. Objectives We sought to determine whether removal of dates from common laboratory test panels offers any advantage in protecting such data from re-identification. Methods We obtained a set of results for 5.9 million laboratory panels from the National Institutes of Health’s (NIH) Biomedical Translational Research Information System (BTRIS), selected a random set of 20,000 panels from the larger source sets, and then identified all matches between the sets. Results We found that while removal of dates could hinder the re-identification of a single test result, such removal had almost no effect when entire panels were used. Conclusions Our results suggest that reliance on chrononymization provides a false sense of security for the protection of laboratory test results. As a result of this study, the NIH has chosen to rely on policy solutions, such as strong data use agreements, rather than removal of dates when reusing clinical data for research purposes. PMID:23646086
7. False-color composite of Oetztal, Austria
NASA Technical Reports Server (NTRS)
1994-01-01
This image is a false-color composite of Oetztal, Austria located in the Central Alps centered at 46.8 degrees north latitude, 10.70 degrees east longitude, at the border between Switzerland (top), Italy (left) and Austria (right and bottom). The area shown is 50 kilometers (30 miles) south of Inssbruck, Austria. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperature Radar (SIR-C/X-SAR) flying on the Space Shuttle Endeavour on its 14th orbit. Approximately one quarter of this image is covered by glaciers, the largest of which, Gepatschferner, is visible as a triangular yellow patch in the center of the scene. The blue areas are lakes (Gepatsch dam at center right; Lake Muta at top right) and glacier ice. The yellow areas are slopes facing the radar and areas of dry snow. Purple corresponds to slopes facing away from the radar. Yellow in the valley bottom corresponds to tree covered areas. The Jet Propulsion Laboratory alternative photo number is P-43890.
8. Possible and False Biomarkers from Space
NASA Technical Reports Server (NTRS)
Bernstein, Max P.
2004-01-01
The Search for life in the Solar System is one of NASA's main goals for the coming decade. We may never observe alien life directly; we or our robotic craft may always be removed from it by many years, or meters of crust. If we do find evidence of Life elsewhere in the Solar System it will probably be in form of chemical biomarkers, quintessentially biological molecules that indicate the presence of micro-organisms. What molecules would be truly indicative of alien life? Chlorophyll fragments, which are often used by geochemists are probably far too specific. Simpler molecules, such as fatty acids, amino acids and nucleo-bases might seem to be biomarkers, but they can form non-biotically in space. Alkyl substituted aromatics in ALH 84001 have been invoked as biomarkers, but they are not strong evidence in and of themselves. Understanding the range of nonbiological organic molecules which could act as false biomarkers in space is a prerequisite for any reasonable search for true biomarkers on other worlds. When simple organics arrive at the surface of a body like Europa, either from below or from space, how long do they survive and what do they make? How can we distinguish these from real biomarkers? In this talk I will present some ideas about what might be useful qualities to consider in a potential biomarker, and will ask for advice from the attendant geochemists.
9. Avoiding the False Peaks in Correlation Discrimination
SciTech Connect
Awwal, A S
2009-07-31
Fiducials imprinted on laser beams are used to perform video image based alignment of the 192 laser beams in the National Ignition Facility (NIF) of Lawrence Livermore National Laboratory. In many video images, matched filtering is used to detect the location of these fiducials. Generally, the highest correlation peak is used to determine the position of the fiducials. However, when the signal to-be-detected is very weak compared to the noise, this approach totally breaks down. The highest peaks act as traps for false detection. The active target images used for automatic alignment in the National Ignition Facility are examples of such images. In these images, the fiducials of interest exhibit extremely low intensity and contrast, surrounded by high intensity reflection from metallic objects. Consequently, the highest correlation peaks are caused by these bright objects. In this work, we show how the shape of the correlation is exploited to isolate the valid matches from hundreds of invalid correlation peaks, and therefore identify extremely faint fiducials under very challenging imaging conditions.
10. Geophysics Fatally Flawed by False Fundamental Philosophy
Myers, L. S.
2004-05-01
For two centuries scientists have failed to realize Laplace's nebular hypothesis \$$1796\$$ of Earth's creation is false. As a consequence, geophysicists today are misinterpreting and miscalculating many fundamental aspects of the Earth and Solar System. Why scientists have deluded themselves for so long is a mystery. The greatest error is the assumption Earth was created 4.6 billion years ago as a molten protoplanet in its present size, shape and composition. This assumption ignores daily accretion of more than 200 tons/day of meteorites and dust, plus unknown volumes of solar insolation that created coal beds and other biomass that increased Earth's mass and diameter over time! Although the volume added daily is minuscule compared with Earth's total mass, logic and simple addition mandates an increase in mass, diameter and gravity. Increased diameter from accretion is proved by Grand Canyon stratigraphy that shows a one kilometer increase in depth and planetary radius at a rate exceeding three meters \$$10 ft\$$ per Ma from start of the Cambrian \$$540 Ma\$$ to end of the Permian \$$245 Ma\$$-each layer deposited onto Earth's surface. This is unequivocal evidence of passive external growth by accretion, part of a dual growth and expansion process called "Accreation" \$$creation by accretion\$$. Dynamic internal core expansion, the second stage of Accreation, did not commence until the protoplanet reached spherical shape at 500-600 km diameter. At that point, gravity-powered compressive heating initiated core melting and internal expansion. Expansion quickly surpassed the external accretion growth rate and produced surface volcanoes to relieve explosive internal tectonic pressure and transfer excess mass (magma)to the surface. Then, 200-250 Ma, expansion triggered Pangaea's breakup, first sundering Asia and Australia to form the Pacific Ocean, followed by North and South America to form the Atlantic Ocean, by the mechanism of midocean ridges, linear underwater
11. Frog Swarms: Earthquake Precursors or False Alarms?
PubMed Central
Grant, Rachel A.; Conlan, Hilary
2013-01-01
Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by
12. Excluding False Positive Detections in Kepler Data
Caldwell, John J.; Ouvarova, T.; Borucki, W. J.
2006-09-01
The NASA Kepler Mission, scheduled for launch in 2008, will search for Earth-size planets orbiting Sun-like stars in or near habitable zones. A high precision photometer will search for planetary transits of parent stars. For a system similar to the Earth-Sun, the decrease in light during a central transit will be one part in 10,000 of the total stellar brightness out of transit. This poster discusses the effort to address a significant concern: the possibility of false positive detections of extra-solar Earth analogs. The concern arises because about 50 per cent of star systems are double or multiple. Further, because the photometer design is constrained by the requirement for high sensitivity to changes of low light levels, the optical resolution is not high compared to other space or terrestrial telescopes. If a relatively nearby Kepler target star happens to contain, within the Kepler PSF, an eclipsing binary system that is reduced in brightness by a factor of 10,000, say because it is 100 times farther away, the photometric profile of an eclipse could mimic a planetary transit. We have therefore developed a program to use archival data from the Hubble Space Telescope to quantify the number density of faint stars in the Kepler field that are in the brightness range that could cause confusion. Since the beginning of the project, the location of the Kepler field itself has been changed to optimize observing efficiency. The work originally included HST/WFPC2 data, and has now been expanded to ACS data as well. We present here a summary of completed and continuing work on faint background systems in the new Kepler field.
13. Blue Polar Dunes In False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
The small dunes in this image are 'bluer' than the rest of the layered ice/dust units to the left.
Image information: VIS instrument. Latitude 84.5, Longitude 206.6 East (153.4 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
14. Dunes and Clouds in False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
The small greenish features in this image are sand dunes. The white feature on the right side is likely an ice cloud.
Image information: VIS instrument. Latitude 84.6, Longitude 203.1 East (156.9 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
15. A Frosty Rim In False Color
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site]
The theme for the weeks of 1/17 and 1/24 is the north polar region of Mars as seen in false color THEMIS images. Ice/frost will typically appear as bright blue in color; dust mantled ice will appear in tones of red/orange.
Our final image combines the features of the past two days, with a dust covered frosty crater rim and the bluer sand dunes of the north polar region.
Image information: VIS instrument. Latitude 70.1, Longitude 351.8 East (8.2 West). 40 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
16. Controlling the Rate of GWAS False Discoveries
PubMed Central
Brzyski, Damian; Peterson, Christine B.; Sobczyk, Piotr; Candès, Emmanuel J.; Bogdan, Malgorzata; Sabatti, Chiara
2017-01-01
With the rise of both the number and the complexity of traits of interest, control of the false discovery rate (FDR) in genetic association studies has become an increasingly appealing and accepted target for multiple comparison adjustment. While a number of robust FDR-controlling strategies exist, the nature of this error rate is intimately tied to the precise way in which discoveries are counted, and the performance of FDR-controlling procedures is satisfactory only if there is a one-to-one correspondence between what scientists describe as unique discoveries and the number of rejected hypotheses. The presence of linkage disequilibrium between markers in genome-wide association studies (GWAS) often leads researchers to consider the signal associated to multiple neighboring SNPs as indicating the existence of a single genomic locus with possible influence on the phenotype. This a posteriori aggregation of rejected hypotheses results in inflation of the relevant FDR. We propose a novel approach to FDR control that is based on prescreening to identify the level of resolution of distinct hypotheses. We show how FDR-controlling strategies can be adapted to account for this initial selection both with theoretical results and simulations that mimic the dependence structure to be expected in GWAS. We demonstrate that our approach is versatile and useful when the data are analyzed using both tests based on single markers and multiple regression. We provide an R package that allows practitioners to apply our procedure on standard GWAS format data, and illustrate its performance on lipid traits in the North Finland Birth Cohort 66 cohort study. PMID:27784720
17. Spirit View of 'Wishstone' (False Color)
NASA Technical Reports Server (NTRS)
2005-01-01
[figure removed for brevity, see original site] Figure 1
Scientists working with NASA's Mars Exploration Rover Spirit decided to examine this rock, dubbed 'Wishstone,' based on data from the miniature thermal emission spectrometer. That instrument's data indicated that the mineralogy of the rocks in this area is different from that of rocks encountered either on the plains of Gusev Crater or in bedrock outcrops examined so far in the 'Columbia Hills' inside the crater. Spirit used its rock abrasion tool first to scour a patch of the rock's surface with a wire brush, then to grind away the surface to reveal interior material. Placement of the rover's alpha particle X-ray spectrometer on the exposed circle of interior material revealed that the rock is rich in phosphorus. Spirit used its panoramic camera during the rover's 342nd martian day, or sol, (Dec. 18, 2004) to take the three individual images that were combined to produce this false-color view emphasizing the freshly ground dust around the hole cut by the rock abrasion tool.
Unusually Rich in Phosophorus The graph in figure 1 compares the elemental makeup of a rock dubbed 'Wishstone' with the average composition of rocks that Spirit examined on the western spur of the 'Columbia Hills.' Wishstone lies farther into the hills than that spur. It is richer in phosphorus than any other Mars rock ever examined. Scientists plan to examine other rocks near Wishstone to help explain the significance of the high phosphorus concentration. The vertical scale is the ratio of the concentration of an element in the hills rocks to the concentration of the same element in a typical volcanic rock from the plains that Spirit crossed to reach the hills.
18. Natural and False Color Views of Europa
NASA Technical Reports Server (NTRS)
1996-01-01
This image shows two views of the trailing hemisphere of Jupiter's ice-covered satellite, Europa. The left image shows the approximate natural color appearance of Europa. The image on the right is a false-color composite version combining violet, green and infrared images to enhance color differences in the predominantly water-ice crust of Europa. Dark brown areas represent rocky material derived from the interior, implanted by impact, or from a combination of interior and exterior sources. Bright plains in the polar areas (top and bottom) are shown in tones of blue to distinguish possibly coarse-grained ice (dark blue) from fine-grained ice (light blue). Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. This crater has been provisionally named 'Pwyll' for the Celtic god of the underworld.
Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon. This image was taken on September 7, 1996, at a range of 677,000 kilometers (417,900 miles) by the solid state imaging television camera onboard the Galileo spacecraft during its second orbit around Jupiter. The image was processed by Deutsche Forschungsanstalt fuer Luftund Raumfahrt e.V., Berlin, Germany.
The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo
19. Blind sequential lineup administration reduces both false identifications and confidence in those false identifications.
PubMed
Charman, Steve D; Quiroz, Vanessa
2016-10-01
One of the most recommended procedures proposed by eyewitness experts is the use of double-blind lineups, in which the administrator does not know the identity of the suspect in the lineup. But despite the near universality of this recommendation, there is surprisingly little empirical research to support the claim that nonblind administration inflates false identifications. What little research has been conducted has shown conflicting findings with regard to the conditions under which nonblind administration affects false identifications, as well as its effects on witness confidence. The current study attempts to elucidate this effect. Student-participants (n = 312) were randomly assigned to play the role of either a lineup administrator (who were either told the identity of the suspect in the lineup or not) or a mock crime witness. Following unbiased instructions, administrators presented either a target-present or target-absent sequential lineup to the witness while being surreptitiously videorecorded. Nonblind administration significantly inflated false, but not correct, identifications, and significantly inflated witness confidence in those false identifications. Video recordings indicated that nonblind administrators were significantly more likely than blind administrators to smile (a) while the witness was viewing a photograph of the suspect, and (b) after a suspect identification. Results provide stronger support for the use of blind lineup administration by broadening the conditions under which nonblind administration is shown to inflate false identifications. Possible reconciliations for conflicting findings in the literature are discussed. (PsycINFO Database Record
20. DSM-5, psychiatric epidemiology and the false positives problem.
PubMed
Wakefield, J C
2015-06-01
The revision effort leading to the publication of the fifth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was flawed in process, goals and outcome. The revision process suffered from lack of an adequate public record of the rationale for changes, thus shortchanging future scholarship. The goals, such as dimensionalising diagnosis, incorporating biomarkers and separating impairment from diagnosis, were ill-considered and mostly abandoned. However, DSM-5's greatest problem, and the target of the most vigorous and sustained criticism, was its failure to take seriously the false positives problem. By expanding diagnosis beyond plausible boundaries in ways inconsistent with DSM-5's own definition of disorder, DSM-5 threatened the validity of psychiatric research, including especially psychiatric epidemiology. I present four examples: increasing the symptom options while decreasing the diagnostic threshold for substance use disorder, elimination of the bereavement exclusion from major depression, allowing verbal arguments as evidence of intermittent explosive disorder and expanding attention-deficit/hyperactivity disorder to adults before addressing its manifest false positives problems.
1. Inflation after false vacuum decay: Observational prospects after Planck
Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo
2015-04-01
We assess two potential signals of the formation of our universe by the decay of a false vacuum. Negative spatial curvature is one possibility, but the window for its detection is now small. However, another possible signal is a suppression of the cosmic microwave background (CMB) power spectrum at large angles. This arises from the steepening of the effective potential as it interpolates between a flat inflationary plateau and the high barrier separating us from our parent vacuum. We demonstrate that these two effects can be parametrically separated in angular scale. Observationally, the steepening effect appears to be excluded at large ℓ; but it remains consistent with the slight lack of power below ℓ≈30 found by the WMAP and Planck collaborations. We give two simple models which improve the fit to the Planck data; one with observable curvature and one without. Despite cosmic variance, we argue that future CMB polarization and most importantly large-scale structure observations should be able to corroborate the Planck anomaly if it is real. If we further assume the specific theoretical setting of a landscape of metastable vacua, as suggested by string theory, we can estimate the probability of seeing a low-ℓ suppression in the CMB. There are significant theoretical uncertainties in such calculations, but we argue the probability for a detectable suppression may be as large as O (1 ), and in general is significantly larger than the probability of seeing curvature.
2. False-positive and false-negative rates in meconium drug testing.
PubMed
Moore, C; Lewis, D; Leikin, J
1995-11-01
To determine the number of false-negative results produced by inefficient extraction of drugs from meconium, three published procedures were compared by using previously confirmed positive and negative meconium specimens. The methods were not equivalent in their ability to extract drugs from the matrix. To determine the number of false positives reported by the use of screen-only (unconfirmed) results, 535 screen-positive meconium specimens were subjects to confirmation by gas chromatography-mass spectrometry. Fifty-seven percent of the samples were confirmed positive for one or more of the drugs under investigation, showing that a false-positive rate as high as 43% may exist when unconfirmed screening results are used.
3. 'Lyell' Panorama inside Victoria Crater (False Color)
NASA Technical Reports Server (NTRS)
2008-01-01
During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.
Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'
This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce this view, which is presented in a false-color stretch to bring out subtle color differences in the scene. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.
4. False Color Mosaic Great Red Spot
NASA Technical Reports Server (NTRS)
1996-01-01
False color representation of Jupiter's Great Red Spot (GRS) taken through three different near-infrared filters of the Galileo imaging system and processed to reveal cloud top height. Images taken through Galileo's near-infrared filters record sunlight beyond the visible range that penetrates to different depths in Jupiter's atmosphere before being reflected by clouds. The Great Red Spot appears pink and the surrounding region blue because of the particular color coding used in this representation. Light reflected by Jupiter at a wavelength (886 nm) where methane strongly absorbs is shown in red. Due to this absorption, only high clouds can reflect sunlight in this wavelength. Reflected light at a wavelength (732 nm) where methane absorbs less strongly is shown in green. Lower clouds can reflect sunlight in this wavelength. Reflected light at a wavelength (757 nm) where there are essentially no absorbers in the Jovian atmosphere is shown in blue: This light is reflected from the deepest clouds. Thus, the color of a cloud in this image indicates its height. Blue or black areas are deep clouds; pink areas are high, thin hazes; white areas are high, thick clouds. This image shows the Great Red Spot to be relatively high, as are some smaller clouds to the northeast and northwest that are surprisingly like towering thunderstorms found on Earth. The deepest clouds are in the collar surrounding the Great Red Spot, and also just to the northwest of the high (bright) cloud in the northwest corner of the image. Preliminary modeling shows these cloud heights vary over 30 km in altitude. This mosaic, of eighteen images (6 in each filter) taken over a 6 minute interval during the second GRS observing sequence on June 26, 1996, has been map-projected to a uniform grid of latitude and longitude. North is at the top.
Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet
5. Panorama from 'Cape Verde' (False Color)
NASA Technical Reports Server (NTRS)
2007-01-01
NASA's Mars Exploration Rover Opportunity captured this vista of 'Victoria Crater' from the viewpoint of 'Cape Verde,' one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).
The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. 'Duck Bay,' where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is 'Cabo Frio,' about 150 meters (500 feet) from the rover. On the left side of the panorama is 'Cape St. Mary,' the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.
The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.
This view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet). It is presented in false
6. Gusev Rocks Solidified from Lava (False Color)
NASA Technical Reports Server (NTRS)
2006-01-01
to identify rocks and features investigated by Spirit during the Chinese New Year celebration period. In ancient Chinese myth, FuYi was the first great emperor and lived in the east. He explained the theory of 'Yin' and 'Yang' to his people, invented the net to catch fish, was the first to use fire to cook food, and invented a musical instrument known as the 'Se' to accompany his peoples' songs and dances. Other rocks and features are being informally named for Chinese gods, warriors, inventors, and scientists, as well as rivers, lakes, and mountains.
Spirit took this image on the rover's Martian day, or sol, 731 (Jan. 23, 2006). This is a false-color composite combining images taken with the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters.
7. False Memory ≠ False Memory: DRM Errors Are Unrelated to the Misinformation Effect
PubMed Central
Ost, James; Blank, Hartmut; Davies, Joanna; Jones, Georgina; Lambert, Katie; Salmon, Kelly
2013-01-01
The DRM method has proved to be a popular and powerful, if controversial, way to study ‘false memories’. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r = −.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM ‘false memories’ and misinformation effect ‘false memories’ do not appear to be equivalent. PMID:23573186
8. Shoulder separation - aftercare
MedlinePlus
Separated shoulder - aftercare; Acromioclavicular joint separation - aftercare; A/C separation - aftercare ... Most shoulder separation injuries are caused by falling onto the shoulder. This causes a tear in the tissue that connects the ...
9. False-evidence ploys and interrogations: mock jurors' perceptions of false-evidence ploy type, deception, coercion, and justification.
PubMed
Forrest, Krista D; Woody, William Douglas; Brady, Sara E; Batterman, Keller C; Stastny, Bradley J; Bruns, Jennifer A
2012-01-01
We studied mock jurors' evaluations of police false-evidence ploys across two false-evidence ploy information conditions (true or false confession). Study 1 participants evaluated lists of demeanor, testimonial, and scientific ploys and rated testimonial false-evidence ploys as more coercive than demeanor false-evidence ploys. Participants in the false-confession condition rated false-evidence ploys as more deceptive than did participants in the true-confession condition. Study 2 participants evaluated false-evidence ploy types within interrogation transcripts. Participants rated testimonial false-evidence ploys as more deceptive and coercive than demeanor false-evidence ploys; participants in the true-confession condition rated false-evidence ploys as more justified. Across studies, participants reading realistic transcripts rated false-evidence ploys as more deceptive and coercive. We discuss implications for scholars, attorneys, and interrogators.
10. High False Positives and False Negatives in Yeast Parameter in an Automated Urine Sediment Analyzer
PubMed Central
Aydin, Ozgur; Ellidag, Hamit Yasar; Eren, Esin; Yilmaz, Necat
2015-01-01
Summary Background Automated urine sediment analyzers have proven their feasibility in medical laboratories. However, editing manual microscopic review of some specimens severely limits the usefulness of such systems. This study aims to give feedback on the practical experience on »Yeast«, which is one of the parameters that compel frequent manual reviews. Methods 5448 freshly collected urine specimens submitted from various departments of our hospital for diagnostic urinalysis were studied by the UriSed® (77 Elektronika, Hungary). A specialist medical doctor inspected every image on-board, and reviewed the ones with a »Yeast« alarm by traditional manual microscopy. Results UriSed alarmed in 491 samples (9%) for yeast. In 59 samples (1%) the number of particles exceeded the cut-off and a »positive for yeast« was set. A false positive report of yeast +1 to 3+/HPF was found in 51 samples (0.9%). There were 8 cases with positive for yeast from both microscopic methods. Thirty-three »negative for yeast« samples were corrected as positive after the manual microscopic review. Conclusions We report a high percentage of false positives and negatives in the yeast parameter, in line with other studies on UriSed as well as on other instruments in the market. As an important feedback, our observations showed that the major concern in false results was »the focusing problem«. We believe in the necessity of a focus check and comparison of alarms between images on board. PMID:28356844
11. 16 CFR 803.90 - Separability.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Separability. 803.90 Section 803.90 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 TRANSMITTAL RULES § 803.90 Separability. If...
12. 16 CFR 803.90 - Separability.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Separability. 803.90 Section 803.90 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 TRANSMITTAL RULES § 803.90 Separability. If...
13. 16 CFR 803.90 - Separability.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Separability. 803.90 Section 803.90 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 TRANSMITTAL RULES § 803.90 Separability. If...
14. 16 CFR 803.90 - Separability.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Separability. 803.90 Section 803.90 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 TRANSMITTAL RULES § 803.90 Separability. If...
15. 16 CFR 803.90 - Separability.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Separability. 803.90 Section 803.90 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976 TRANSMITTAL RULES § 803.90 Separability. If...
16. 11 CFR 9006.1 - Separate reports.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 11 Federal Elections 1 2010-01-01 2010-01-01 false Separate reports. 9006.1 Section 9006.1 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND: GENERAL ELECTION FINANCING... report all expenditures to further the candidate's general election campaign in reports separate...
17. 9 CFR 3.133 - Separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Separation. 3.133 Section 3.133 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.133 Separation. Animals housed in the same...
18. 9 CFR 3.109 - Separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Separation. 3.109 Section 3.109 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.109 Separation. Marine mammals, whenever known to...
19. 9 CFR 3.109 - Separation.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Separation. 3.109 Section 3.109 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.109 Separation. Marine mammals, whenever known to...
20. 9 CFR 3.133 - Separation.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Separation. 3.133 Section 3.133 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.133 Separation. Animals housed in the same...
1. 9 CFR 3.133 - Separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Separation. 3.133 Section 3.133 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.133 Separation. Animals housed in the same...
2. 9 CFR 3.133 - Separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Separation. 3.133 Section 3.133 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.133 Separation. Animals housed in the same...
3. 9 CFR 3.109 - Separation.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Separation. 3.109 Section 3.109 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.109 Separation. Marine mammals, whenever known to...
4. 9 CFR 3.109 - Separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Separation. 3.109 Section 3.109 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.109 Separation. Marine mammals, whenever known to...
5. 9 CFR 3.109 - Separation.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Separation. 3.109 Section 3.109 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.109 Separation. Marine mammals, whenever known to...
6. 9 CFR 3.133 - Separation.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Separation. 3.133 Section 3.133 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... Mammals Animal Health and Husbandry Standards § 3.133 Separation. Animals housed in the same...
7. 7 CFR 1160.508 - Separability.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 9 2012-01-01 2012-01-01 false Separability. 1160.508 Section 1160.508 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Miscellaneous § 1160.508 Separability. If any provision of this subpart is declared invalid or the...
8. 7 CFR 1160.508 - Separability.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 9 2011-01-01 2011-01-01 false Separability. 1160.508 Section 1160.508 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Miscellaneous § 1160.508 Separability. If any provision of this subpart is declared invalid or the...
9. 7 CFR 1160.508 - Separability.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 9 2013-01-01 2013-01-01 false Separability. 1160.508 Section 1160.508 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Miscellaneous § 1160.508 Separability. If any provision of this subpart is declared invalid or the...
10. 16 CFR 1512.20 - Separability.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Separability. 1512.20 Section 1512.20 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.20 Separability. If any section or portion thereof of this...
11. Abort Trigger False Positive and False Negative Analysis Methodology for Threshold-Based Abort Detection
NASA Technical Reports Server (NTRS)
Melcher, Kevin J.; Cruz, Jose A.; Johnson Stephen B.; Lo, Yunnhon
2015-01-01
This paper describes a quantitative methodology for bounding the false positive (FP) and false negative (FN) probabilities associated with a human-rated launch vehicle abort trigger (AT) that includes sensor data qualification (SDQ). In this context, an AT is a hardware and software mechanism designed to detect the existence of a specific abort condition. Also, SDQ is an algorithmic approach used to identify sensor data suspected of being corrupt so that suspect data does not adversely affect an AT's detection capability. The FP and FN methodologies presented here were developed to support estimation of the probabilities of loss of crew and loss of mission for the Space Launch System (SLS) which is being developed by the National Aeronautics and Space Administration (NASA). The paper provides a brief overview of system health management as being an extension of control theory; and describes how ATs and the calculation of FP and FN probabilities relate to this theory. The discussion leads to a detailed presentation of the FP and FN methodology and an example showing how the FP and FN calculations are performed. This detailed presentation includes a methodology for calculating the change in FP and FN probabilities that result from including SDQ in the AT architecture. To avoid proprietary and sensitive data issues, the example incorporates a mixture of open literature and fictitious reliability data. Results presented in the paper demonstrate the effectiveness of the approach in providing quantitative estimates that bound the probability of a FP or FN abort determination.
12. Adults' Memories of Childhood: True and False Reports
ERIC Educational Resources Information Center
Qin, Jianjian; Ogle, Christin M.; Goodman, Gail S.
2008-01-01
In 3 experiments, the authors examined factors that, according to the source-monitoring framework, might influence false memory formation and true/false memory discernment. In Experiment 1, combined effects of warning and visualization on false childhood memory formation were examined, as were individual differences in true and false childhood…
13. 42 CFR 21.23 - False statements as disqualification.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 42 Public Health 1 2012-10-01 2012-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...
14. 42 CFR 21.23 - False statements as disqualification.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...
15. 42 CFR 21.23 - False statements as disqualification.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 42 Public Health 1 2013-10-01 2013-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...
16. 42 CFR 21.23 - False statements as disqualification.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 42 Public Health 1 2014-10-01 2014-10-01 false False statements as disqualification. 21.23 Section 21.23 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false...
17. Relations between Mental Verb and False Belief Understanding in Cantonese-Speaking Children
ERIC Educational Resources Information Center
Cheung, Him; Chen, Hsuan-Chih; Yeung, William
2009-01-01
Previous research has shown that linguistic forms that codify mental contents bear a specific relation with children's false belief understanding. These forms include mental verbs and their following complements, yet the two have not been considered separately. The current study examined the roles of mental verb semantics and the complement syntax…
18. 'Gibson' Panorama by Spirit at 'Home Plate' (False Color)
NASA Technical Reports Server (NTRS)
2006-01-01
NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as 'Home Plate.' The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the 'U' shape of the mosaic. In reality, the features along the 1-meter to 2-meter (1-foot to 6.5-foot) vertical exposure of the rim of Home Plate in this vicinity are relatively level. Rocks near the rover in this view, known as the 'Gibson' panorama, include 'Barnhill,' 'Rogan,' and 'Mackey.'
Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover. This image is a false-color rendering using using Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters, presented to enhance many subtle color differences between rocks and soils in the scene. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.
19. 21 CFR 864.9245 - Automated blood cell separator.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated blood cell separator. 864.9245 Section... Blood and Blood Products § 864.9245 Automated blood cell separator. (a) Identification. An automated blood cell separator is a device that uses a centrifugal or filtration separation principle...
20. 21 CFR 864.9245 - Automated blood cell separator.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated blood cell separator. 864.9245 Section... Blood and Blood Products § 864.9245 Automated blood cell separator. (a) Identification. An automated blood cell separator is a device that uses a centrifugal or filtration separation principle...
1. 21 CFR 864.9245 - Automated blood cell separator.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated blood cell separator. 864.9245 Section... Blood and Blood Products § 864.9245 Automated blood cell separator. (a) Identification. An automated blood cell separator is a device that uses a centrifugal or filtration separation principle...
2. 9 CFR 381.26 - Separation of establishments.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Separation of establishments. 381.26... Establishment Numbers; Separation of Establishments and Other Requirements; Withdrawal of Inspection § 381.26 Separation of establishments. Each official establishment shall be separate and distinct from any...
3. 47 CFR 73.807 - Minimum distance separation between stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 4 2012-10-01 2012-10-01 false Minimum distance separation between stations... separation between stations. Minimum separation requirements for LP100 and LP10 stations, as defined in §§ 73... the co-channel, first- and second-adjacent and IF channel separations are met. An LPFM station...
4. 47 CFR 73.507 - Minimum distance separations between stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 4 2010-10-01 2010-10-01 false Minimum distance separations between stations... separations between stations. (a) Minimum distance separations. No application for a new station, or change in... proposed facilities will be located so as to meet the adjacent channel distance separations specified...
5. 9 CFR 381.26 - Separation of establishments.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Separation of establishments. 381.26... Establishment Numbers; Separation of Establishments and Other Requirements; Withdrawal of Inspection § 381.26 Separation of establishments. Each official establishment shall be separate and distinct from any...
6. 9 CFR 381.26 - Separation of establishments.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Separation of establishments. 381.26... Establishment Numbers; Separation of Establishments and Other Requirements; Withdrawal of Inspection § 381.26 Separation of establishments. Each official establishment shall be separate and distinct from any...
7. 49 CFR 1242.06 - Instructions for separation.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 9 2014-10-01 2014-10-01 false Instructions for separation. 1242.06 Section 1242... BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON... Instructions for separation. (a) Certain instructions for separating common expense accounts...
8. 47 CFR 73.507 - Minimum distance separations between stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 4 2012-10-01 2012-10-01 false Minimum distance separations between stations... separations between stations. (a) Minimum distance separations. No application for a new station, or change in... proposed facilities will be located so as to meet the adjacent channel distance separations specified...
9. 20 CFR 322.7 - Dismissal, coordination, and separation allowances.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Dismissal, coordination, and separation... UNEMPLOYMENT INSURANCE ACT REMUNERATION § 322.7 Dismissal, coordination, and separation allowances. (a... paid benefits. (b) Separation allowance. A separation allowance or severance payment made to...
10. 14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false System separation: EWIS. 25.1707 Section 25... System separation: EWIS. (a) Each EWIS must be designed and installed with adequate physical separation... condition. Unless otherwise stated, for the purposes of this section, adequate physical separation must...
11. 47 CFR 73.507 - Minimum distance separations between stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 4 2013-10-01 2013-10-01 false Minimum distance separations between stations... separations between stations. (a) Minimum distance separations. No application for a new station, or change in... proposed facilities will be located so as to meet the adjacent channel distance separations specified...
12. 9 CFR 381.26 - Separation of establishments.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Separation of establishments. 381.26... Establishment Numbers; Separation of Establishments and Other Requirements; Withdrawal of Inspection § 381.26 Separation of establishments. Each official establishment shall be separate and distinct from any...
13. 14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false System separation: EWIS. 25.1707 Section 25... System separation: EWIS. (a) Each EWIS must be designed and installed with adequate physical separation... condition. Unless otherwise stated, for the purposes of this section, adequate physical separation must...
14. 49 CFR 1242.06 - Instructions for separation.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 9 2010-10-01 2010-10-01 false Instructions for separation. 1242.06 Section 1242... BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON... Instructions for separation. (a) Certain instructions for separating common expense accounts...
15. 47 CFR 73.807 - Minimum distance separation between stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 4 2010-10-01 2010-10-01 false Minimum distance separation between stations... separation between stations. Minimum separation requirements for LP100 and LP10 stations, as defined in §§ 73... these separations are met. Minimum distances for co-channel and first-adjacent channel are...
16. 49 CFR 1242.06 - Instructions for separation.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 9 2012-10-01 2012-10-01 false Instructions for separation. 1242.06 Section 1242... BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON... Instructions for separation. (a) Certain instructions for separating common expense accounts...
17. 14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false System separation: EWIS. 25.1707 Section 25... System separation: EWIS. (a) Each EWIS must be designed and installed with adequate physical separation... condition. Unless otherwise stated, for the purposes of this section, adequate physical separation must...
18. 14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false System separation: EWIS. 25.1707 Section 25... System separation: EWIS. (a) Each EWIS must be designed and installed with adequate physical separation... condition. Unless otherwise stated, for the purposes of this section, adequate physical separation must...
19. 9 CFR 381.26 - Separation of establishments.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Separation of establishments. 381.26... Establishment Numbers; Separation of Establishments and Other Requirements; Withdrawal of Inspection § 381.26 Separation of establishments. Each official establishment shall be separate and distinct from any...
20. 20 CFR 322.7 - Dismissal, coordination, and separation allowances.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Dismissal, coordination, and separation... UNEMPLOYMENT INSURANCE ACT REMUNERATION § 322.7 Dismissal, coordination, and separation allowances. (a... paid benefits. (b) Separation allowance. A separation allowance or severance payment made to...
1. 49 CFR 1242.06 - Instructions for separation.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 9 2013-10-01 2013-10-01 false Instructions for separation. 1242.06 Section 1242... BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS SEPARATION OF COMMON... Instructions for separation. (a) Certain instructions for separating common expense accounts...
2. 20 CFR 322.7 - Dismissal, coordination, and separation allowances.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Dismissal, coordination, and separation... UNEMPLOYMENT INSURANCE ACT REMUNERATION § 322.7 Dismissal, coordination, and separation allowances. (a... paid benefits. (b) Separation allowance. A separation allowance or severance payment made to...
3. 47 CFR 73.807 - Minimum distance separation between stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 4 2014-10-01 2014-10-01 false Minimum distance separation between stations... separation between stations. Minimum separation requirements for LPFM stations are listed in the following...- and second-adjacent channel separations are met. An LPFM station need not satisfy the...
4. 14 CFR 25.1707 - System separation: EWIS.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false System separation: EWIS. 25.1707 Section 25... System separation: EWIS. (a) Each EWIS must be designed and installed with adequate physical separation... condition. Unless otherwise stated, for the purposes of this section, adequate physical separation must...
5. 47 CFR 73.807 - Minimum distance separation between stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 4 2013-10-01 2013-10-01 false Minimum distance separation between stations... separation between stations. Minimum separation requirements for LPFM stations are listed in the following...- and second-adjacent channel separations are met. An LPFM station need not satisfy the...
6. 47 CFR 73.507 - Minimum distance separations between stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 4 2014-10-01 2014-10-01 false Minimum distance separations between stations... separations between stations. (a) Minimum distance separations. No application for a new station, or change in... proposed facilities will be located so as to meet the adjacent channel distance separations specified...
7. 21 CFR 864.9245 - Automated blood cell separator.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated blood cell separator. 864.9245 Section... Blood and Blood Products § 864.9245 Automated blood cell separator. (a) Identification. An automated blood cell separator is a device that uses a centrifugal or filtration separation principle...
8. 21 CFR 864.9245 - Automated blood cell separator.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated blood cell separator. 864.9245 Section... Blood and Blood Products § 864.9245 Automated blood cell separator. (a) Identification. An automated blood cell separator is a device that uses a centrifugal or filtration separation principle...
9. 46 CFR 162.050-21 - Separator: Design specification.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 6 2010-10-01 2010-10-01 false Separator: Design specification. 162.050-21 Section 162... Separator: Design specification. (a) A separator must be designed to operate in each plane that forms an.... (c) Each separator component that is a moving part must be designed so that its movement...
10. 46 CFR 162.050-21 - Separator: Design specification.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 6 2014-10-01 2014-10-01 false Separator: Design specification. 162.050-21 Section 162... Separator: Design specification. (a) A separator must be designed to operate in each plane that forms an.... (c) Each separator component that is a moving part must be designed so that its movement...
11. "False negatives" and "false positives" in acute pulmonary embolism: a clinical-postmortem comparison.
PubMed
Mandelli, V; Schmid, C; Zogno, C; Morpurgo, M
1997-02-01
Although recent advances have been made in understanding its epidemiology, diagnosis and treatment, pulmonary embolism (PE) is still largely undetected and untreated, and the mortality rate has not appreciably changed in the last decades. The aim of this study was to: compare the postmortem frequency of massive and sub-massive PE during two different time periods in the same general hospital; ascertain whether the percentage of correct clinical diagnosis of PE has changed; identify factors which might contribute to the inaccuracy of the clinical diagnosis of PE. Altogether, 288 patients with autopsy-proven PE and adequate clinical data were collected in the first period; 182 subjects with the same characteristics were found in the second period. Cases observed from 1989 through 1994 were evaluated in terms of frequency of false negatives and false positives, predictive value of the clinical diagnosis of PE, and correlations between clinical and post-mortem diagnosis of PE on one side and several independent variables such as age, gender, associated diseases, recent surgery on the other. In our hospital the frequency of massive and submassive PE at autopsy was 8.6% from 1966 through 1974, 12.6% from 1989 through 1994 (p < 0.01). The percentage of correct clinical diagnosis of PE was 19.6% in the former period, 21.6% in the latter (NS) with 78.57% of false negatives and only 1.73% of false positives. Altogether the true positives were 21.42%, most of them being patients with massive PE. Clinical findings showed the coexistence of heart disease in 51.6% of the cases, congestive heart failure in 20.15%, metabolic disease in 7%, stroke in 12.5%, recent surgery in 12.5%. Autopsy revealed the presence of pulmonary infarction in 22% of cases, malignancy in 24.0%, pneumonia in 17.05%, acute myocardial infarction in 14.8%. Seventy percent of the cases in whom the point of origin of thromboemboli could be demonstrated had one or more thrombus in the district of inferior vena
12. Belief and sign, true and false: the unique of false belief reasoning.
PubMed
Zhang, Ting; Zhang, Qin; Li, Yiyuan; Long, Changquan; Li, Hong
2013-11-01
For a long time, a controversy has been proposed that whether the process of theory of mind is a result of domain-specific or domain-general changes (Wellman in The handbook of childhood cognitive development. Blackwell Publication, New Jersey, 2011). This event-related potential study explored the neural time course of domain-general and domain-specific components in belief reasoning. Fourteen participants completed location transfer false belief (FB), true belief (TB), false sign (FS) and true sign (TS) tasks, in which two pictures told a story related to a dog that ran from a green into a red box. In the TB and FB tasks, a boy saw or did not see the transfer of the dog, respectively. In the FS and TS tasks, an arrow that pointed to the green box either altered its direction to the red box or did not alter following the transfer of the dog. Participants then inferred where the boy thought of, or the arrow indicated the location of the dog. FB and TB reasoning elicited lower N2 amplitudes than FS and TS reasoning, which is associated with domain-general components, the detection, and classification. The late slow wave (LSW) for FB was more positive at frontal, central, and parietal sites than FS because of the domain-specific component involved in FB reasoning. However, the LSW was less positive for TB than for FB but did not differ from the TS condition, which implies that mental representation might not be involved in TB reasoning.
13. Ferrofluid separator for nonferrous scrap separation
NASA Technical Reports Server (NTRS)
Kaiser, R.; Mir, L.
1974-01-01
Behavior of nonmagnetic objects within separator is essentially function of density, and independent of size or shape of objects. Results show close agreement between density of object and apparent density of ferrofluid required to float it. Results also demonstrate that very high separation rates are achievable by ferrofluid sink-float separation.
14. Dissociated developmental trajectories for semantic and phonological false memories.
PubMed
Holliday, Robyn E; Weekes, Brendan S
2006-07-01
False recognition following presentation of semantically related and phonologically related word lists was evaluated in 8-, 11-, and 13-year-olds. Children heard lists of words that were either semantic (e.g., bed, rest, wake ...) or phonological associates (e.g., pole, bowl, hole ...) of a critical unpresented word (e.g., sleep, roll), respectively. A semantic false memory was defined as false recognition of a semantically related but unpresented word. A phonological false memory was defined as false recognition of a phonologically related but unpresented word. False memories in the two tasks showed opposite developmental trends, increasing with age for semantic relatedness and decreasing with age for phonological relatedness.
15. An effective method for controlling false discovery and false nondiscovery rates in genome-scale RNAi screens.
PubMed
Zhang, Xiaohua Douglas
2010-10-01
In most genome-scale RNA interference (RNAi) screens, the ultimate goal is to select siRNAs with a large inhibition or activation effect. The selection of hits typically requires statistical control of 2 errors: false positives and false negatives. Traditional methods of controlling false positives and false negatives do not take into account the important feature in RNAi screens: many small-interfering RNAs (siRNAs) may have very small but real nonzero average effects on the measured response and thus cannot allow us to effectively control false positives and false negatives. To address for deficiencies in the application of traditional approaches in RNAi screening, the author proposes a new method for controlling false positives and false negatives in RNAi high-throughput screens. The false negatives are statistically controlled through a false-negative rate (FNR) or false nondiscovery rate (FNDR). FNR is the proportion of false negatives among all siRNAs examined, whereas FNDR is the proportion of false negatives among declared nonhits. The author also proposes new concepts, q*-value and p*-value, to control FNR and FNDR, respectively. The proposed method should have broad utility for hit selection in which one needs to control both false discovery and false nondiscovery rates in genome-scale RNAi screens in a robust manner.
16. Telling true from false: cannabis users show increased susceptibility to false memories.
PubMed
Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A
2015-06-01
Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring.
17. Telling true from false: cannabis users show increased susceptibility to false memories
PubMed Central
Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A
2015-01-01
Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring. PMID:25824306
18. False alarms: How early warning signals falsely predict abrupt sea ice loss
Wagner, Till J. W.; Eisenman, Ian
2015-12-01
Uncovering universal early warning signals for critical transitions has become a coveted goal in diverse scientific disciplines, ranging from climate science to financial mathematics. There has been a flurry of recent research proposing such signals, with increasing autocorrelation and increasing variance being among the most widely discussed candidates. A number of studies have suggested that increasing autocorrelation alone may suffice to signal an impending transition, although some others have questioned this. Here we consider variance and autocorrelation in the context of sea ice loss in an idealized model of the global climate system. The model features no bifurcation, nor increased rate of retreat, as the ice disappears. Nonetheless, the autocorrelation of summer sea ice area is found to increase in a global warming scenario. The variance, by contrast, decreases. A simple physical mechanism is proposed to explain the occurrence of increasing autocorrelation but not variance when there is no approaching bifurcation. Additionally, a similar mechanism is shown to allow an increase in both indicators with no physically attainable bifurcation. This implies that relying on autocorrelation and variance as early warning signals can raise false alarms in the climate system, warning of "tipping points" that are not actually there.
19. False-Object Identification for Space Surveillance Catalog Maintenance
Pittelkau, M.
2016-09-01
A space object from a surveillance catalog of space objects that is predicted to be in the field of view of a tracking sensor may not be detected by a tracking sensor because of viewing conditions, or because either the estimated orbit of the space object has large error or the catalog object does not actually exist. In these two latter cases we call such a catalog object an invalid object (a false or lost track). Identification of invalid catalog objects is an essential function for maintenance of a space surveillance catalog. An invalid catalog object is not likely to be associable with any measurements (observations) in a sequence of data collects from tracking sensors. The sequential probability of validity over multiple frames of data is cumulative evidence of whether the catalog object is valid or invalid. The catalog object is deemed to be invalid when the sequential probability of validity is sufficiently close to zero. The single-frame and sequential probabilities of validity of a catalog object are determined by first computing the maximum likelihood association of the tracks (the estimated orbits) and observations, and then by updating a sequential likelihood ratio test for each track. The probability that each track is valid is computed from likelihood ratios. The algorithm is simpler and computationally faster than the general Multiple Hypothesis Testing (MHT) algorithm that associates multiple measurements and multiple objects over multiple frames of data. The sequential data collects do not have to correspond to the same set of catalog objects, and the data collects can be separated in time and can come from tracking sensors that are geographically separated, have different views, and that report different types of measurements (angles, range, range rate, position vectors, or position and velocity vectors). The measurement data can include feature (attribute) data. The only condition is that the catalog object under consideration is predicted to be
20. Dynamics of false vacuum bubbles with nonminimal coupling
SciTech Connect
Lee, Bum-Hoon; Lee, Chul H.; Lee, Wonwoo; Nam, Siyoung; Park, Chanyong
2008-03-15
We study the dynamics of false vacuum bubbles. A nonminimally coupled scalar field gives rise to the effect of negative tension. The mass of a false vacuum bubble from an outside observer's point of view can be positive, zero, or negative. The interior false vacuum has de Sitter geometry, while the exterior true vacuum background can have geometry depending on the vacuum energy. We show that there exist expanding false vacuum bubbles without the initial singularity in the past. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.27813777327537537, "perplexity": 9717.469130133211}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187825154.68/warc/CC-MAIN-20171022075310-20171022095310-00358.warc.gz"} |
http://math.stackexchange.com/questions/91641/find-a-parametrization-of-the-curve-x-frac23-y-frac23-1-and | # Find a parametrization of the curve $x^{\frac{2}{3}} + y^{\frac{2}{3}} = 1$ and use it to compute the area of the interior.
I have the following homework question that I know the answer to $(3\pi/8)$, however, I don't understand how to get this answer.
The question:
Find a parametrization of the curve $x^{\frac{2}{3}} + y^{\frac{2}{3}} = 1$ and use it to compute the area of the interior.
http://www2.math.umd.edu/~jmr/241/lineint2.htm
I don't understand though. I understand how they make $u = x^{\frac{1}{2}}$ and $y = y^{\frac{1}{2}}$ so they could get $u^2 + v^2 = 1$, which is a nice trick. I can see how they parameterized that to $u = \cos t$, $v = \sin t$ from $t = 0$ to $t = 2\pi$. I just don't get what they do next.
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you should read the section directly above it "the connection with area" that explains how to compute area as is done in example 5 – yoyo Dec 15 '11 at 2:37
Since I presume you already know $\cos^2 u+\sin^2 u=1$, set $x^\frac23=\cos^2 u$ (and similarly for $y$), and solve for $x$ and $y$ in those two equations. The curve you have, BTW, is called an astroid. – Ｊ. Ｍ. Dec 15 '11 at 2:40
You want $u=x^{\frac 13},\ v=y^{\frac 13}$ – Ross Millikan Dec 15 '11 at 4:50
They are using "Green's Theorem" to compute areas using line integrals.
Roughly Green's theorem tells you how to turn a double integral into a line integral or vice-versa.
A little more detail: Let $C$ be the boundary of some 2D region $R$ and let $C$ be oriented counter-clockwise. In addition, suppose that $P(x,y)$ and $Q(x,y)$ have continuous first partials. Then
$$\iint_R \frac{\partial Q}{\partial x} - \frac{\partial P}{\partial y}\,dA = \int_C P\,dx+Q\,dy$$
Next, $\iint_R 1\,dA$ computes the area of $R$ just as $\int_a^b 1\,dt$ computes the length of $[a,b]$, $\int_C 1\,ds$ computes the arc length of $C$, $\iiint_E 1\,dV$ computes the volume of $E$, etc.
If you can pick out $P$ and $Q$ such that $\frac{\partial Q}{\partial x} - \frac{\partial P}{\partial y}=1$, then by Green's theorem, the corresponding line integral will compute the area of $R$. Note that, for example, $\frac{\partial Q}{\partial x} - \frac{\partial P}{\partial y}=1$ when $Q=x$ and $P=0$ or $Q=0$ and $P=-y$ or $Q=x/2$ and $P=-y/2$.
Therefore, $$\iint_R 1\,dA = \int_C x\,dy = \int_C -y\,dx = \int_C -y/2\,dx+x/2\,dy$$
So if $R$ is the region bounded by $C$ where $C$ is the curve $x^{2/3}+y^{2/3}=1$. Then $\int_C x\,dy$ will compute the area of $R$ (given $C$ is oriented counter-clockwise). So we parametrize $C$ using ${\bf r}(t) = \langle x(t),y(t) \rangle = \langle \cos^3(t), \sin^3(t) \rangle$ and $0 \leq t \leq 2\pi$. [Note: $x^{2/3}+y^{2/3} = (\cos^3(t))^{2/3}+(\sin^3(t))^{2/3} = \cos^2(t)+\sin^2(t)=1$.]
Thus $x = \cos^3(t)$ and $dy = y'(t)\,dt = 3\sin^2(t)\cos(t)\,dt$. Therefore,
$$\mathrm{Area}(R) = \iint_R 1\,dA = \int_C x\,dy = \int_0^{2\pi} \cos^3(t) \cdot 3\sin^2(t)\cos(t)\,dt = \frac{3\pi}{8}$$
See Wolfram Alpha - indefinite and Wolfram Alpha - definite for the details regarding the evaluation of this integral.
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Bill, you are just the man today! – user13327 Dec 15 '11 at 3:45 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9798075556755066, "perplexity": 175.02448886267362}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413510834349.43/warc/CC-MAIN-20141017015354-00107-ip-10-16-133-185.ec2.internal.warc.gz"} |
http://mathhelpforum.com/algebra/121388-y-function-x.html | # Math Help - Y a function of X?
1. ## Y a function of X?
Could someone please assist and advise if the following equation determines Y to be a function of X : y2 = x + 3 ? (the 2 is an exponent) Thanks much!
2. Originally Posted by jay1
Could someone please assist and advise if the following equation determines Y to be a function of X : y2 = x + 3 ? (the 2 is an exponent) Thanks much!
Hi jay1,
If $y^2=x+3$, then $y=f(x)=\pm \sqrt{x+3}$
$f(x)=\pm \sqrt{x+3}$ is a parabola with vertex on the x-axis and opening to the right. By definition, it is not a function. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 3, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8768893480300903, "perplexity": 507.4516113351442}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398459333.27/warc/CC-MAIN-20151124205419-00042-ip-10-71-132-137.ec2.internal.warc.gz"} |
https://repository.uantwerpen.be/link/irua/81059 | $\phi$ weighting" template method on a lepton plus isolated track sample"> $\phi$ weighting" template method on a lepton plus isolated track sample"> Measurement of the top quark mass at CDF using the "neutrino <tex>$\phi$</tex> weighting" template method on a lepton plus isolated track sample - Institutional Repository University of Antwerp
Title Measurement of the top quark mass at CDF using the "neutrino $\phi$ weighting" template method on a lepton plus isolated track sample Author Aaltonen, T. Van Remortel, N. et al. Faculty/Department Faculty of Sciences. Physics Publication type article Publication 2009 Lancaster, Pa , 2009 Subject Physics Source (journal) Physical review : D : particles and fields. - Lancaster, Pa, 1970 - 2003 Volume/pages 79(2009) :7 , p. 072005,1-072005,18 ISSN 0556-2821 ISI 000266408300008 Carrier E Target language English (eng) Full text (Publishers DOI) Affiliation University of Antwerp Abstract We present a measurement of the top quark mass with tt̅ dilepton events produced in pp̅ collisions at the Fermilab Tevatron (√s=1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb-1, are selected as tt̅ candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles (ϕν1,ϕν2) of neutrinos and reconstruct the top quark mass for each ϕν1, ϕν2 pair by minimizing a χ2 function in the tt̅ dilepton hypothesis. We assign χ2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated tt̅ and background events, and parametrized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5-3.3+3.4(stat)±3.1(syst) GeV/c2. Full text (open access) https://repository.uantwerpen.be/docman/irua/637794/31c47c97.pdf E-info http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266408300008&DestLinkType=RelatedRecords&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266408300008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266408300008&DestLinkType=CitingArticles&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 Handle | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6718488931655884, "perplexity": 3945.8420920327717}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917119361.6/warc/CC-MAIN-20170423031159-00212-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://iop.figshare.com/articles/_Upper_panel_participation_ratio_a_href_http_iopscience_iop_org_0953_4075_46_14_145302_article_jpb46/1012170/1 | ## Upper panel: participation ratio (7) as functions of time for the parameters of figure 1
2013-06-13T00:00:00Z (GMT) by
Figure 2. Upper panel: participation ratio (7) as functions of time for the parameters of figure 1. Lower panel: the same yet F = 0.015, F_x/F_y=(\sqrt{5}-1)/4\approx 0.309. Dashed lines show the participation ratio calculated by using the tight-binding model.
Abstract
We analyse dynamics of a quantum particle in a square lattice in the Hall configuration beyond the single-band approximation. For vanishing gauge (magnetic) field this dynamics is defined by the inter-band Landau–Zener tunnelling, which is responsible for the phenomenon known as the electric breakdown. We show that in the presence of a gauge field this phenomenon is absent, at least, in its common sense. Instead, the Landau–Zener tunnelling leads to the appearance of a finite current which flows in the direction orthogonal to the vector of a potential (electric) field.
CC BY 4.0 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9434968829154968, "perplexity": 813.3387602780607}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540529745.80/warc/CC-MAIN-20191211021635-20191211045635-00418.warc.gz"} |
https://paperswithcode.com/search?q=author%3ADeepan+Muthirayan | Graph Learning for Cognitive Digital Twins in Manufacturing Systems
In this paper, we detail the cognitive digital twin as the next stage of advancement of a digital twin that will help realize the vision of Industry 4. 0.
Online Learning Robust Control of Nonlinear Dynamical Systems
We show that when the controller has preview of the cost functions and the disturbances for a short duration of time and the system is known $R^p_T(\gamma) = O(1)$ when $\gamma \geq \gamma_c$, where $\gamma_c = \mathcal{O}(\overline{\gamma})$.
Generative Adversarial Imitation Learning for Empathy-based AI
Generative adversarial imitation learning (GAIL) is a model-free algorithm that has been shown to provide strong results in imitating complex behaviors in high-dimensional environments.
Dynamic Matching Markets in Power Grid: Concepts and Solution using Deep Reinforcement Learning
Traditional bulk load flexibility options, such as load shifting and load curtailment, for managing uncertainty in power markets limit the diversity of options and ignore the preferences of the individual loads, thus reducing efficiency and welfare.
Neuroscience-Inspired Algorithms for the Predictive Maintenance of Manufacturing Systems
If machine failures can be detected preemptively, then maintenance and repairs can be performed more efficiently, reducing production costs.
Meta-Learning Guarantees for Online Receding Horizon Learning Control
In this paper we provide provable regret guarantees for an online meta-learning receding horizon control algorithm in an iterative control setting, where in each iteration the system to be controlled is a linear deterministic system that is different and unknown, the cost for the controller in an iteration is a general additive cost function and the control input is required to be constrained, which if violated incurs an additional cost.
Regret Guarantees for Online Receding Horizon Learning Control
In this paper we provide provable regret guarantees for an online learning receding horizon type control policy in a setting where the system to be controlled is an unknown linear dynamical system, the cost for the controller is a general additive function over a finite period $T$, and there exist control input constraints that when violated incur an additional cost.
Optimization and Control Systems and Control Systems and Control
Scene-Graph Augmented Data-Driven Risk Assessment of Autonomous Vehicle Decisions
Finally, we demonstrate that the use of spatial and temporal attention layers improves our model's performance by 2. 7% and 0. 7% respectively, and increases its explainability.
15
A Meta-Learning Control Algorithm with Provable Finite-Time Guarantees
In this work we provide provable regret guarantees for an online meta-learning control algorithm in an iterative control setting, where in each iteration the system to be controlled is a linear deterministic system that is different and unknown, the cost for the controller in an iteration is a general additive cost function and the control input is required to be constrained, which if violated incurs an additional cost.
Cannot find the paper you are looking for? You can Submit a new open access paper. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.566536545753479, "perplexity": 894.8498007363224}, "config": {"markdown_headings": false, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057131.88/warc/CC-MAIN-20210921011047-20210921041047-00517.warc.gz"} |
http://thevirtuosi.blogspot.fr/2013/ | ## Sunday, June 23, 2013
### Tragedy of Great Power Politics? Modeling International War
Recently I finished reading John Mearsheimer's excellent political science book The Tragedy of Great Power Politics. In this book, Mearscheimer lays out his offensive realism'' theory of how countries interact with each other in the world. The book is quite readable and well-thought-out -- I'd recommend it to anyone who has an inkling for political history and geopolitics. However, as I was reading this book, I decided that there was a point of Mearsheimer's argument which could be improved by a little mathematical analysis.
## Sunday, January 20, 2013
### Re-evaluating the values of the tiles in Scrabble™
Recently I have seen quite a few blog posts written about re-evaluating the points values assigned to the different letter tiles in the Scrabble™ brand Crossword Game. The premise behind these posts is that the creator and designer of the game assigned point values to the different tiles according to their relative frequencies of occurrence in words in English text, supplemented by information gathered while playtesting the game. The points assigned to different letters reflected how difficult it was to play those letters: common letters like E, A, and R were assigned 1 point, while rarer letters like J and Q were assigned 8 and 10 points, respectively. These point values were based on the English lexicon of the late 1930’s. Now, some 70 years later, that lexicon has changed considerably, having gained many new words (e.g.: EMAIL) and lost a few old ones. So, if one were to repeat the analysis of the game designer in the present day, would one come to different conclusions regarding how points should be assigned to various letters?
## Tuesday, January 1, 2013
### The Skeleton Supporting Search Engine Ranking Systems
A lot of the research I’m interested in relates to networks – measuring the properties of networks and figuring out what those properties mean. While doing some background reading, I stumbled upon some discussion of the algorithm that search engines use to rank search results. The automatic ranking of the results that come up when you search for something online is a great example of how understanding networks (in this case, the World Wide Web) can be used to turn a very complicated problem into something simple.
Ranking search results relies on the assumption that there is some underlying pattern to how information is organized on the WWW- there are a few core websites containing the bulk of the sought-after information surrounded by a group of peripheral websites that reference the core. Recognizing that the WWW is a network representation of how information is organized and using the properties of the network to detect where that information is centered are the key components to figuring out what websites belong at the top of the search page. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.36831358075141907, "perplexity": 1082.49179276027}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084891705.93/warc/CC-MAIN-20180123012644-20180123032644-00237.warc.gz"} |
https://sdk.numxl.com/help/ndk-pcr-fitted | # NDK_PCR_FITTED
int __stdcall NDK_PCR_FITTED ( double ** X, size_t nXSize, size_t nXVars, LPBYTE mask, size_t nMaskLen, double * Y, size_t nYSize, double intercept, WORD nRetType )
Returns an array of cells for the i-th principal component (or residuals).
Returns
status code of the operation
Return values
NDK_SUCCESS Operation successful NDK_FAILED Operation unsuccessful. See Macros for full list.
Parameters
[in] X is the independent variables data matrix, such that each column represents one variable [in] nXSize is the number of observations (i.e. rows) in X [in] nXVars is the number of variables (i.e. columns) in X [in] mask is the boolean array to select a subset of the input variables in X. If missing (i.e. NULL), all variables in X are included. [in] nMaskLen is the number of elements in mask [in,out] Y is the response or the dependent variable data array (one dimensional array) [in] nYSize is the number of elements in Y [in] intercept is the constant or the intercept value to fix (e.g. zero). If missing (NaN), an intercept will not be fixed and is computed normally [in] nRetType is a switch to select the return output fitted values (default), residuals, standardized residuals, leverage (H), Cook's distance.
Remarks
1. li>The underlying model is described here.
2. The regression fitted (aka estimated) conditional mean is calculated as follows: $\hat y_i = E \left[ Y| x_i1\cdots x_ip \right] = \alpha + \hat \beta_1 \times x_i1 + \cdots + \beta_p \times x_ip$ Residuals are defined as follows: $e_i = y_i - \hat y_i$ The standardized (aka studentized) residuals are calculated as follows: $\bar e_i = \frac{e_i}{\hat \sigma_i}$ Where:
• $$\hat y$$is the estimated regression value.
• $$e$$ is the error term in the regression.
• $$\hat e$$ is the standardized error term.
• $$\hat \sigma_i$$ is the standard error for the i-th observation.
3. For the influential data analysis, PCR_FITTED computes two values: leverage statistics and Cook's distance for observations in our sample data.
4. Leverage statistics describe the influence that each observed value has on the fitted value for that same observation. By definition, the diagonal elements of the hat matrix are the leverages. $H = X \left(X^\top X \right)^{-1} X^\top$ $L_i = h_{ii}$ Where:
• $$H$$ is the Hat matrix for uncorrelated error terms.
• $$\mathbf{X}$$ is a (N x p+1) matrix of explanatory variable where the first column is all ones.
• $$L_i$$ is the leverage statistics for the i-th observation.
• $$h_{ii}$$ is the i-th diagonal element in the hat matrix.
5. Cook's distance measures the effect of deleting a given observation. Data points with large residuals (outliers) and/or high leverage may distort the outcome and accuracy of a regression. Points with a large Cook's distance are considered to merit closer examination in the analysis. $D_i = \frac{e_i^2}{p \ \mathrm{MSE}}\left[\frac{h_{ii}}{(1-h_{ii})^2}\right]$ Where:
• $$D_i$$ is the Cook's distance for the i-th observation.
• $$h_{ii}$$ is the leverage statistics (or the i-th diagonal element in the hat matrix).
• $$\mathrm{MSE}$$ is the mean square error of the regression model.
• $$p$$ is the number of explanatory variables.
• $$e_i$$ is the error term (residual) for the i-th observation.
6. The sample data may include missing values.
7. Each column in the input matrix corresponds to a separate variable.
8. Each row in the input matrix corresponds to an observation.
9. Observations (i.e. row) with missing values in X or Y are removed.
10. The number of rows of the response variable (Y) must be equal to the number of rows of the explanatory variables (X).
11. The MLR_FITTED function is available starting with version 1.60 APACHE.
Requirements | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7928955554962158, "perplexity": 2149.2494655888086}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764499646.23/warc/CC-MAIN-20230128153513-20230128183513-00624.warc.gz"} |
https://control.com/textbook/digital-data-acquisition-and-networks/ethernet-networks/ | # Ethernet networks: Repeaters, Cabling and Switching Hubs
## Chapter 6 - Digital Data Acquisition and Networks in Control Systems
An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973, while working for the Xerox research center in Palo Alto, California. His fundamental invention was the CSMA/CD method of channel arbitration, allowing multiple devices to share a common channel of communication while recovering gracefully from inevitable “collisions.” In Metcalfe’s vision, all of the “network intelligence” would be built directly into “controller” devices situated between the DTE devices (computers, terminals, printers, etc.) and a completely passive coaxial cable network. Unlike some other networks in operation at the time, Metcalfe’s did not rely on additional devices to help coordinate communications between DTE devices. The coaxial cable linking DTE devices together would be completely passive and “dumb,” performing no task but the conduction of broadcast signals between all devices. In that sense, it served the same purpose as the “luminiferous ether” once believed to fill empty space: conducting electromagnetic waves between separated points.
The CSMA/CD (“Carrier Sense Multiple Access with Collision Detection”) method of bus arbitration works by giving each Ethernet device the ability to sense an idle channel as well as sense if it happens to “collide” with another transmitting device. In the event of a collision, the colliding devices both cease transmission, and set random time-delays to wait before re-transmission. The individual time delays are randomized to decrease the probability that a re-collision between the same devices will occur after the wait. This strategy is analogous to several peers in one group holding a conversation, where all people involved are equally free to begin speaking, and equally deferential to their peers if ever two or more accidently begin speaking at the same time. Occasional collisions are perfectly normal in an Ethernet network, and should not be taken as an indication of trouble unless their frequency becomes severe.
Metcalfe’s original network design operated at a data rate of 2.94 Mbps, impressive for its time. By 1980, the three American computer companies DEC (Digital Equipment Corporation), Intel, and Xerox had collaborated to revise the Ethernet design to a speed of 10 Mbps, and released a standard called the DIX Ethernet standard (the acronym “DIX” representing the first letter of each company’s name). Later, the IEEE Local and Metropolitan Networks Standards Committee codified the DIX Ethernet standard under the numeric label 802.3. At the present time there exist many “supplemental” standards underneath the basic 802.3 definition, a few of them listed here:
• 802.3a-1985 10BASE2 “thin” Ethernet
• 802.3i-1990 10BASE-T twisted-pair cable Ethernet
• 802.3u-1995 100BASE-T “Fast” Ethernet and Auto-Negotiation
• 802.3x-1997 Full-Duplex standard
• 802.3ab-1999 1000BASE-T “Gigabit” Ethernet over twisted-pair cable
The IEEE 802.3 standard is limited to layers 1 and 2 of the OSI Reference Model: the “Physical” and “Data link” layers. In the physical layer (1), the various supplements describe all the different ways in which bits are electrically or optically represented, as well as permissible cable and connector types. In the data link layer (2), the IEEE standard describes how devices are addressed (each one with a unique identifier known as a MAC address, consisting of a 48-bit binary number usually divided into six bytes, each byte written as a two-character hexadecimal number), the CSMA/CD channel arbitration protocol, and also how data frames are organized for Ethernet transmissions.
### Repeaters (hubs)
Bob Metcalfe’s original design for Ethernet consisted of DTE devices connected to a common coaxial cable through the use of “tee” connectors, like this:
This cabling arrangement suffered several problems. First, it was inconvenient to run through an office building, since each DTE device needed to be coupled rather closely to the main “trunk.” Short cable segments (called stubs, spurs, or drops) joining the main trunk line to each DTE device could not be too long, or else they would could cause multiple signal reflections to occur in the main line. Secondly, the signal strength decreased with each “tee” connector: every time the signal branched, it would lose power. Thirdly, the need for termination resistors at the far ends of the “ether” cable opened up the possibility that those terminators might fail, fall off, or be forgotten during installation or maintenance.
As Ethernet evolved as a practical networking standard, one of the many improvements added to its design was the concept of a repeating hub. A “repeater” is an active device designed to re-broadcast a signal, usually to overcome inevitable power losses incurred as that signal propagates along a cable. Repeaters are common in the telecommunications industry, where telephone, television, and computer signals must travel hundreds or thousands of miles between points of transmission and reception. A “repeating hub” is a repeater with multiple ports for many cables to plug into, where any signal entering on any cable is repeated to all ports on the device. Thus, a repeating hub (or simply “hub”) allows multiple Ethernet devices to interconnect with no degradation in signal quality:
Not only do hubs improve system performance by boosting signals’ voltage levels, but they also eliminate the need for termination resistors in the network. With a hub-based system, each and every cable terminates at either a DTE or DCE device, which is (now) designed with the proper termination resistance built-in to their internal transceiver circuitry. This means each and every Ethernet cable is automatically terminated with the proper impedance simply by plugging it in to the Ethernet port of any device. “Stub” or “spur” cables with their length restrictions are also a thing of the past, since no cable ever splits or branches in a hub-based network system.
Hubs are considered “layer 1” devices, because they operate purely on the physical layer of Ethernet: all they do is receive Ethernet signals and re-broadcast those signals in boosted form to all other devices plugged into the hub. As a piece of interconnecting hardware, a hub is considered a DCE (Data Communications Equipment), as opposed to the end-of-cable devices such as computers and printers which are DTEs (Data Terminal Equipment).
Repeating hubs may be connected together to form larger networks:
Since hubs are merely “layer 1” devices, mindlessly boosting and re-broadcasting signals received to their ports, their presence does not mitigate collisions between transmitting devices. As far as collisions between those devices is concerned, they might as well be directly connected together on a single piece of coaxial cable. One way to express this concept is to say that all portions of the network are part of the same collision domain. In other words, any devices on this network are able to collide with each other, because all transmissions are sensed by all the devices. This is analogous to a small room with several people in it: the room is small enough that everyone can hear everyone else talking, which means only one person in that room is able to speak at a time.
### Ethernet cabling
Along with hubs came another form of Ethernet cable and connector: unshielded, twisted pair (UTP) wiring and RJ-45 “flat” connectors. These cables use multiple twisted pairs of wires instead of the coaxial cable specified in Metcalfe’s original Ethernet. The purpose of using twisted-wire pairs is to reduce magnetic signal coupling.
For 10 Mbps Ethernet over UTP cable (called 10BASE-T) and for 100 Mbps Ethernet (called 100BASE-TX), only two out of four available wire pairs are used:
Pin number Assignment Abbreviation
1 Transmit Data (+) TD+
2 Transmit Data ($-$) TD$-$
4 (not used)
5 (not used)
6 Receive Data ($-$) RD$-$
7 (not used)
8 (not used)
It should be noted that 1000 Mbps (“Gigabit”) Ethernet over twisted-wire pairs does in fact use all four pairs in an eight-wire cable, a departure from traditional UTP Ethernet cable wiring:
Pin number Assignment Abbreviation
1 Pair A'' (+) BI\_DA+
2 Pair A'' ($-$) BI\_DA$-$
3 Pair B'' (+) BI\_DB+
4 Pair C'' (+) BI\_DC+
5 Pair C'' ($-$) BI\_DC$-$
6 Pair B'' ($-$) BI\_DB$-$
7 Pair D'' (+) BI\_DD+
8 Pair D'' ($-$) BI\_DD$-$
Along with UTP cables and RJ-45 connectors came a significant alteration to the basic electrical scheme of Ethernet. Metcalfe’s original design used a simple coaxial cable as the “ether” connecting devices together. Such cables had only two conductors, meaning each device needed to transmit and receive data over the same two conductors. With UTP cable’s four pairs of conductors, transmission and reception of signals occurs over different wire pairs. This means connections made between Ethernet devices must employ a “swap” between TD and RD wire pairs in order for communication to take place, so that the “receiver” circuitry of one device connects to the “transmitter” circuitry of the other, and vice-versa. This is precisely the same characteristic inherent to EIA/TIA-232 and four-wire EIA/TIA-485 networks, where separate wire pairs are dedicated to “transmit” and “receive” functions.
In a typical Ethernet system, the interconnecting hubs perform this transmit/receive swap. Hubs are considered DCE devices, while computers and other end-of-the-line devices are considered DTE devices. This means the pin assignments of DTE and DCE devices must be different in order to ensure the transmit/receive pin swap necessary for straight-through cables to work. This also means if someone ever wishes to directly connect two Ethernet DTE devices together without the benefit of a hub in between, a special crossover cable must be used for the connection, identical in function to the null modem cable used to connect two EIA/TIA-232 DTE devices together:
Furthermore, the same problem exists when multiple hubs are connected to form larger networks. Since each hub is a DCE device, a straight-through cable connecting two hubs together will pass transmitted signals from one hub directly to the “transmit” pins of the other hub, not the “receive” pins as it needs to. Consequently, a “crossover” cable should be used to connect two Ethernet hubs together in order to avoid this problem:
Some early Ethernet hubs provided a different solution to the “crossover” problem, and that was a crossover switch built into the hub, allowing a person to manually switch the transmit and receive wire pairs with the push of a button. In this next photograph of a four-port Ethernet hub, you can see the “Normal/Uplink” pushbutton on the right-hand side of the front panel, controlling the furthest-right port of the hub. This switch is supposed to be placed in the “Normal” position if the device plugged into that port is a DTE device, and placed in the “Uplink” position if the device is a DCE device (e.g. another hub):
Note the LED indicator lights by each port on the hub. One LED indicates whether or not the cable is active (when a powered Ethernet DTE device is plugged into that port of the hub), while the other LED indicates traffic on the cable (by blinking). These LEDs are very helpful for identifying a crossover problem. This hub even has an LED indicating the occurrence of collisions (the “Col” LED just below the main power LED), giving simple visual indication of collision frequency.
Newer Ethernet DTE and DCE devices use auto-sensing technology to perform any necessary transmit/receive pin swaps, rendering crossover cables and crossover pushbuttons unnecessary for either DTE-to-DTE or hub-to-hub connections. Auto-sensing is a standard feature of 1000BASE-T (“Gigabit” Ethernet).
### Switching hubs
The next evolutionary step in Ethernet network connections is the introduction of a switching hub, or simply switch. A “switch” looks exactly like a repeating hub, but it contains intelligence to route transmitted signals only to specific ports, rather than broadcasting every received data frame to all ports. What enables this to happen is the information contained in each Ethernet frame transmitted by DTE devices:
Note that part of the frame includes both a source address and a destination address. These refer to the 48-bit “MAC” addresses uniquely identifying each and every Ethernet device. A switching hub “learns” the identities of all devices plugged into each of its ports by remembering the “source” addresses received through those ports. When a switch receives an Ethernet frame with a destination address it recognizes as residing on one of its ports, it only repeats that frame to that specific port, and not to the other ports. In other words, an Ethernet switch does not mindlessly broadcast all messages to all of its ports the way an Ethernet hub does. The switch’s targeted direction of messages reduces the amount of “traffic” seen at the other ports, and also avoids unnecessary collisions because messages only get sent to their intended destinations.
If a switch receives a data frame with an unrecognized destination address, it defaults to basic “hub” behavior by broadcasting that frame to all ports. If a device plugged into one of that switch’s ports replies to that data frame, the MAC address of that device is noted for future traffic direction to that port.
The presence of a switching hub in a larger network has the effect of dividing that network into separate collision domains, so that a collision occurring in one domain does not “spill over” into another domain where it would delay communication between those devices:
Of course, collisions between these two domains may still occur, for instance if a device in the first domain tries to transmit to a device in the second domain at the exact same time that a device in the second domain attempts to transmit to a device in the first.
With this added intelligence, switching hubs are considered “layer 2” devices, since they operate not just at the physical layer of electrical impulses, but also at the next layer of device addressing. Since switching hubs add benefit beyond repeating hubs without any drawbacks, most people elect to use switches whenever possible.
Published under the terms and conditions of the Creative Commons Attribution 4.0 International Public License | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18328018486499786, "perplexity": 3791.5723096769343}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057421.82/warc/CC-MAIN-20210923104706-20210923134706-00660.warc.gz"} |
https://dml.cz/handle/10338.dmlcz/140738 | # Article
Full entry | PDF (0.4 MB)
Keywords:
0-distributive lattice; $\alpha$-ideal; annihilator ideal; quasi-complemented lattice
Summary:
In a 0-distributive lattice sufficient conditions for an $\alpha$-ideal to be an annihilator ideal and prime ideal to be an $\alpha$-ideal are given. Also it is proved that the images and the inverse images of $\alpha$-ideals are $\alpha$-ideals under annihilator preserving homomorphisms.
References:
[1] Balasubramani, P., Venkatanarsimhan: Characterizations of the 0-distributive lattice. Indian J. Pure Appl. Math. 32, 3 (2001), 315–324. MR 1826759
[2] Balasubramani, P.: Stone topology of the set of the set of prime filters of a 0-distributive lattice. Indian J. Pure Appl. Math. 35, 2 (2004), 149–158. MR 2040729
[3] Cornish, W. H.: Annulets and $\propto$-ideals in a distributive lattice. J. Aust. Math. Soc. 15, 1 (1975), 70–77. DOI 10.1017/S1446788700012775 | MR 0344170
[4] Grätzer, G.: Lattice Theory – First concepts and distributive lattices. Freeman and Company, San Francisco, 1971. MR 0321817
[5] Jayaram, C.: Prime $\alpha$-ideals in a 0-distributive lattice. Indian J. Pure Appl. Math. 17, 3 (1986), 331–337. MR 0835346 | Zbl 0595.06010
[6] Pawar, Y. S., Mane, D. N.: $\alpha$-ideals in 0-distributive semilattices and 0-distributive lattices. Indian J. Pure Appl. Math. 24, 7-8 (1993), 435–443. MR 1234802 | Zbl 0789.06005
[7] Varlet, J.: A generalization of the notion of pseudo-complementedness. Bull. Soc. Roy. Liege 37 (1968), 149–158. MR 0228390 | Zbl 0162.03501
Partner of | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.43549609184265137, "perplexity": 3097.419560809591}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496670151.97/warc/CC-MAIN-20191119121339-20191119145339-00227.warc.gz"} |
https://en.wikipedia.org/wiki/Palm%E2%80%93Khintchine_theorem | # Palm–Khintchine theorem
In probability theory, the Palm–Khintchine theorem, the work of Conny Palm and Aleksandr Khinchin, expresses that a large number of not necessarily Poissonian renewal processes combined will have Poissonian properties.[1]
It is used to generalise the behaviour of users or clients in queuing theory. It is also used in dependability and reliability modelling of computing and telecommunications.
According to Heyman and Sobel (2003), the theorem describes that the superposition of a large number of independent equilibrium renewal processes, each with a small intensity, behaves asymptotically like a Poisson process:
Let ${\displaystyle \{N_{i}(t),t\geq 0\},i=1,2,...,m}$ be independent renewal processes and ${\displaystyle \{N(t),t>0\}}$ be the superposition of these processes. Denote by ${\displaystyle X_{2jm}}$ the time between the first and the second renewal epochs in process ${\displaystyle j}$. Define${\displaystyle N_{jm}(t)}$ the ${\displaystyle j}$th counting process, ${\displaystyle F_{jm}(t)=P(X_{2jm}\leq t)}$ and ${\displaystyle \lambda _{jm}=1/(E((X_{2jm)}))}$.
If the following assumptions hold
1) For all sufficiently large ${\displaystyle m}$: ${\displaystyle \lambda _{1m}+\lambda _{2m}+...+\lambda _{mm}=\lambda <\infty }$
2) Given ${\displaystyle \epsilon >0}$, for every ${\displaystyle t>0}$ and sufficiently large ${\displaystyle m}$: ${\displaystyle F_{jm}(t)<\epsilon }$ for all ${\displaystyle j}$
then the superposition ${\displaystyle N_{0m}(t)=N_{1m}(t)+N_{2m}(t)+...+N_{mm}(t)}$ of the counting processes approaches a Poisson process for ${\displaystyle m}$ to ${\displaystyle \infty }$.
## References
1. ^ Daniel P. Heyman, Matthew J. Sobel (2003). "5.8 Superposition of Renewal Processes". Stochastic Models in Operations Research: Stochastic Processes and Operating Characteristics. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 18, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9803948402404785, "perplexity": 870.2480287782581}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917123491.79/warc/CC-MAIN-20170423031203-00207-ip-10-145-167-34.ec2.internal.warc.gz"} |
http://www.c14-demethylase.com/2018/03/22/pendent-homodimer-of-41-6-kda-of-known-crystal-structure-34-35-the-enzyme-condenses/ | # Pendent homodimer of 41.6 kDa of known crystal structure (34, 35). The enzyme condenses
Pendent homodimer of 41.6 kDa of known crystal structure (34, 35). The enzyme condenses alanine with pimeloyl-CoA to give 7-keto-8-amino pelargonic acid (formal name, 8-amino-7oxononanoic acid) plus CoA and CO2 (resulting from decarboxylation of alanine). BioF is a two-domain Acadesine manufacturer protein with the pyridoxal phosphate bound in a crevice between the two domains formed by residues of both domains. The mechanism of the enzyme has been studied in some detail (36). Historically the enzyme has been assayed using pimeloyl-CoA although pimeloyl-ACP could be the physiological substrate in E. coli (ACP-requiring enzymes will often use the analogous CoA compound as a model substrate). Consistent with this notion the E. coli 7-keto-8-amino pelargonic acid synthase has a much higher Michaelis constant for pimeloyl-CoA than the analogous enzyme from Bacillus sphaericus (37), an organism in which pimeloyl-CoA is thought to be the physiological substrate due to the presence of pimeloyl-CoA synthetase. BioA BioA is 7,8-diaminopelargonic acid (DAPA) aminotransferase (the formal name of DAPA is 7,8-diaminononanoate) that has many similarities to BioF, the preceding enzyme in the pathway. Although the BioA subunit (47.3 kDa) is slightly larger than that of BioF, it is also a homodimeric pyridoxal phosphate-dependent enzyme. Indeed, the overall structure of BioA is very similar to that of BioF (38) and this is reflected in a weak sequence homology. BioA is a transaminase that converts KAPA to DAPA and as such is not a particularly interesting enzyme (39, 40). However, the amino donor is not a standard amino acid, but rather the highly activated amino acid SAM (39, 41) which requires three ATP equivalents for its synthesis. The deaminated product derived from SAM, S-adenosyl-2-oxo-4thiomethylbutryate, spontaneously degrades in vitro (39), and thus it seems likely that three ATP equivalents are consumed in what is an otherwise simple transamination reaction. The expense of this perplexing choice of amino donor may provide a rationale for the known tight regulation of biotin synthesis. However, it could be argued that use of a more pedestrian amino donor (B. subtilis uses lysine (42)) could alleviate the need for tight regulation. BioD In contrast to the preceding enzymes BioD (dethiobiotin synthase or DTBS) catalyzes an unusually interesting step, the formation of the ureido moiety of biotin (43, 44). The BioD reaction is the ATP-dependent formation of dethiobiotin from DAPA and CO2. The enzyme is a homodimeric protein (subunit of 24.1 kDa) that is structured into a single well foldedAuthor Manuscript Author Manuscript Author Manuscript Author MK-886 site ManuscriptEcoSal Plus. Author manuscript; available in PMC 2015 January 06.CronanPagedomain (45?8). X-ray crystallographic studies have shown that the reaction proceeds by carbamoylation of N-7 of DAPA (45, 46) (Fig. 3). Independent NMR evidence for carbamate formation has also been obtained (49). The second partial reaction is also unusual. In this reaction the carbamate is activated by transfer of the -phosphoryl moiety of ATP to a carbamate oxygen to form a mixed anhydride (Fig. 3). This mixed anhydride species has been demonstrated by time-resolved crystallography (50). The final step of the dethiobiotin synthase reaction is a nucleophilic attack by the N-8 nitrogen of DAPA on a carbamoyl oxygen of the mixed anhydride (Fig. 3). This results in release of the phosphate group and formation of the ureido ring of dethiobiotin.Pendent homodimer of 41.6 kDa of known crystal structure (34, 35). The enzyme condenses alanine with pimeloyl-CoA to give 7-keto-8-amino pelargonic acid (formal name, 8-amino-7oxononanoic acid) plus CoA and CO2 (resulting from decarboxylation of alanine). BioF is a two-domain protein with the pyridoxal phosphate bound in a crevice between the two domains formed by residues of both domains. The mechanism of the enzyme has been studied in some detail (36). Historically the enzyme has been assayed using pimeloyl-CoA although pimeloyl-ACP could be the physiological substrate in E. coli (ACP-requiring enzymes will often use the analogous CoA compound as a model substrate). Consistent with this notion the E. coli 7-keto-8-amino pelargonic acid synthase has a much higher Michaelis constant for pimeloyl-CoA than the analogous enzyme from Bacillus sphaericus (37), an organism in which pimeloyl-CoA is thought to be the physiological substrate due to the presence of pimeloyl-CoA synthetase. BioA BioA is 7,8-diaminopelargonic acid (DAPA) aminotransferase (the formal name of DAPA is 7,8-diaminononanoate) that has many similarities to BioF, the preceding enzyme in the pathway. Although the BioA subunit (47.3 kDa) is slightly larger than that of BioF, it is also a homodimeric pyridoxal phosphate-dependent enzyme. Indeed, the overall structure of BioA is very similar to that of BioF (38) and this is reflected in a weak sequence homology. BioA is a transaminase that converts KAPA to DAPA and as such is not a particularly interesting enzyme (39, 40). However, the amino donor is not a standard amino acid, but rather the highly activated amino acid SAM (39, 41) which requires three ATP equivalents for its synthesis. The deaminated product derived from SAM, S-adenosyl-2-oxo-4thiomethylbutryate, spontaneously degrades in vitro (39), and thus it seems likely that three ATP equivalents are consumed in what is an otherwise simple transamination reaction. The expense of this perplexing choice of amino donor may provide a rationale for the known tight regulation of biotin synthesis. However, it could be argued that use of a more pedestrian amino donor (B. subtilis uses lysine (42)) could alleviate the need for tight regulation. BioD In contrast to the preceding enzymes BioD (dethiobiotin synthase or DTBS) catalyzes an unusually interesting step, the formation of the ureido moiety of biotin (43, 44). The BioD reaction is the ATP-dependent formation of dethiobiotin from DAPA and CO2. The enzyme is a homodimeric protein (subunit of 24.1 kDa) that is structured into a single well foldedAuthor Manuscript Author Manuscript Author Manuscript Author ManuscriptEcoSal Plus. Author manuscript; available in PMC 2015 January 06.CronanPagedomain (45?8). X-ray crystallographic studies have shown that the reaction proceeds by carbamoylation of N-7 of DAPA (45, 46) (Fig. 3). Independent NMR evidence for carbamate formation has also been obtained (49). The second partial reaction is also unusual. In this reaction the carbamate is activated by transfer of the -phosphoryl moiety of ATP to a carbamate oxygen to form a mixed anhydride (Fig. 3). This mixed anhydride species has been demonstrated by time-resolved crystallography (50). The final step of the dethiobiotin synthase reaction is a nucleophilic attack by the N-8 nitrogen of DAPA on a carbamoyl oxygen of the mixed anhydride (Fig. 3). This results in release of the phosphate group and formation of the ureido ring of dethiobiotin. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8743007183074951, "perplexity": 7865.658883855959}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125937193.1/warc/CC-MAIN-20180420081400-20180420101400-00051.warc.gz"} |
https://lavelle.chem.ucla.edu/forum/search.php?author_id=12763&sr=posts | ## Search found 34 matches
Sat Jun 09, 2018 5:53 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Charge of ligands
Replies: 5
Views: 310
### Re: Charge of ligands
I find using the Lewis structures helpful especially when calculating the coordination complex number and the oxidation number
Sat Jun 09, 2018 5:49 pm
Forum: Identifying Acidic & Basic Salts
Topic: Final
Replies: 3
Views: 329
### Re: Final
I don't think we need to know this. I would look at the outline and see if it is mentioned.
Sat Jun 09, 2018 5:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand bind to metal
Replies: 2
Views: 136
### Re: Ligand bind to metal
I don't think they break because to rotate you have to break the pi bond and that takes too much energy.
Sun Jun 03, 2018 1:07 pm
Forum: Hybridization
Topic: Hybridization and it's relation to valence electrons
Replies: 3
Views: 151
### Re: Hybridization and it's relation to valence electrons
Each C will have three regions of electron density and will need three hybrid orbitals. Trigonal Planar makes each C sp2 hybridized. There will be 3 electrons in the 2sp2 region and 1 unpaired electron in 2p which is higher in energy than the hybridized region. The unhybridized 2p orbital on each C ...
Sun Jun 03, 2018 1:03 pm
Forum: Lewis Structures
Topic: Test Q.8 [ENDORSED]
Replies: 7
Views: 349
### Re: Test Q.8[ENDORSED]
A good trick is to notice that whenever there is more than one oxygen there is probably resonance because that bond can be in different positions. Also a resonance between a single and double bond is between their lengths around 1.33 so it is longer than a double bond but shorter than a single bond.
Sun Jun 03, 2018 1:00 pm
Forum: Biological Examples
Topic: chemotherapy example [ENDORSED]
Replies: 4
Views: 332
### Re: chemotherapy example[ENDORSED]
Cis platin forms a coordination compound with DNA when the two Cl's bind with two Guanine bases in DNA and these bases stop cells division. The CL's bind with the lone pair available on the nitrogen on the Guanine to form a cation. This makes the cis more effective than the trans because the trans h...
Thu May 24, 2018 9:40 pm
Forum: Ionic & Covalent Bonds
Topic: ionic and covalent character
Replies: 7
Views: 735
### Re: ionic and covalent character
Ionic Character has more to do with Electronegativity because the greater the difference in electronegativity the more similar the covalent bond is to an ionic one because the charges are distributed unevenly to a greater degree. Covalent Character has more to do with Polarizability which relates to...
Thu May 24, 2018 9:35 pm
Forum: Lewis Structures
Topic: Test 3 [ENDORSED]
Replies: 4
Views: 435
### Re: Test 3[ENDORSED]
I found it helpful to read chapter 3 in the textbook. We also discussed electronegativity, polarizability, ionic and covalent character and bond strength and length.
Thu May 24, 2018 9:33 pm
Forum: Lewis Structures
Topic: 3.45
Replies: 3
Views: 212
### Re: 3.45
The ones that most likely contribute to the resonance hybrid probably exhibit about the same formal charges. Oxygen is normally a reason that a Lewis Dot structure has resonance and the structures that contribute to the hybrid are the ones that have the lowest possible charges overall. For example, ...
Sun May 20, 2018 4:58 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 11
Views: 595
### Re: formal charge
I know you can just count the bonds for the bonding electrons but I find it helpful to do the 1/2 times the bonding electrons just to make sure.
Sun May 20, 2018 4:55 pm
Forum: Lewis Structures
Topic: Dots vs lines to represent electrons
Replies: 8
Views: 397
### Re: Dots vs lines to represent electrons
I prefer using the dots because it is helpful to calculate formal charge and keep track of valence electrons.
Sun May 20, 2018 4:47 pm
Forum: Lewis Structures
Topic: 3.55
Replies: 6
Views: 203
### Re: 3.55
The radical also normally goes on the central atom.
Wed May 09, 2018 12:14 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Delta X
Replies: 4
Views: 305
### Delta X
I know when delta x is given as +/- 3 for example you multiply the number by 2 for the equation, but when you are given the radius of an atom do you plug in the radius or the diameter into the equation?
Wed May 09, 2018 12:04 am
Forum: Properties of Light
Topic: 4b practice midterm
Replies: 11
Views: 792
### Re: 4b practice midterm
Update: I forgot to add the kinetic energy to the work function before diving by h!
Tue May 08, 2018 11:58 pm
Forum: Properties of Light
Topic: 4b practice midterm
Replies: 11
Views: 792
### Re: 4b practice midterm
I am still very confused and keep getting the wrong answer for this problem. I found v from wavelength=h/mv and then did 1/2m (mass of an electron) v^2 plus the converted work function and got 3.00x10^14
Sun May 06, 2018 10:34 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s and 3d
Replies: 4
Views: 231
### Re: 4s and 3d
I was confused about this too but if you think about it in terms of the lines he drew in class and how the gap gets smaller as you increase in energy level it makes sense that 4 is higher energy than 3 and 5 is higher than 4 and why when we draw electron configurations for ions we remove them from h...
Sun May 06, 2018 10:31 pm
Forum: General Science Questions
Topic: Solutions for tests
Replies: 3
Views: 332
### Re: Solutions for tests
I would look on Chemistry Community because a lot of people have asked questioned about the tests.
Sun May 06, 2018 10:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: half full?
Replies: 5
Views: 207
### Re: half full?
This is similar to how for Chromium and Copper the electron configuration is more stable for example Cr [Ar] 3d5 4s1 is more stable than
Cr [Ar] 3d4 4s2.
Sun May 06, 2018 10:23 pm
Forum: Trends in The Periodic Table
Topic: Trends to Know
Replies: 12
Views: 630
### Re: Trends to Know
I'm pretty sure this won't be on the midterm. The midterm covers Chapter 1 and 2 and the Fundamentals.
Fri Apr 27, 2018 5:20 pm
Forum: DeBroglie Equation
Topic: 1.33 using De Broglie
Replies: 3
Views: 194
### Re: 1.33 using De Broglie
Part C is where the question gets tricky but if you recall the equation Ephoton-Work=E excess(or kinetic energy) we know the mass of the electron and the velocity so we can find the kinetic energy and we know that it takes 1.66x10^-17 to eject the electron from the previous problem so if we rearrang...
Fri Apr 27, 2018 5:16 pm
Forum: DeBroglie Equation
Topic: 1.33 using De Broglie
Replies: 3
Views: 194
### Re: 1.33 using De Broglie
For part B the energy required to remove an electron is the energy of the photon E=hv plugging in v= 2.50 x 10^16 HZ and h and you get 1.66x10^-17 J
Fri Apr 27, 2018 5:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Why does the 4s orbital come before the 3d?
Replies: 7
Views: 412
### Re: Why does the 4s orbital come before the 3d?
3d is at a lower energy level than 4s therefore it comes before it in the electron configuration because it going from lowest to highest energy level.
Fri Apr 27, 2018 5:08 pm
Forum: Photoelectric Effect
Topic: Test 2 final question [ENDORSED]
Replies: 15
Views: 774
### Re: Test 2 final question[ENDORSED]
The test also mentioned that it was a UV light which is important to acknowledge because if it was a longer wavelength then no electrons would be ejected.
Sun Apr 22, 2018 9:31 pm
Forum: Einstein Equation
Topic: E=hv vs E=hf [ENDORSED]
Replies: 4
Views: 1844
### Re: E=hv vs E=hf[ENDORSED]
I was also confused about this! I would argue that velocity and frequency are interchangeable especially because they have the same units.
Sun Apr 22, 2018 9:28 pm
Forum: Significant Figures
Topic: Use of sigfigs
Replies: 8
Views: 470
### Re: Use of sigfigs
Sig Figs are important, but I would argue that making sure you have the right units is also important. Especially when using the speed of light and disproving certain ideas like that an electron is drawn into the nucleus, correct significant figures are essential.
Sun Apr 22, 2018 9:25 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1 Q2
Replies: 2
Views: 211
### Re: Test 1 Q2
I was also confused by this question!! I'm pretty sure we were given for information than we needed in the question and some numbers didn't need to be used.
Sun Apr 22, 2018 9:24 pm
Forum: General Science Questions
Topic: Tools for remembering equations
Replies: 5
Views: 589
### Re: Tools for remembering equations
Yeah I asked Lavelle in class if we need to know the equations and they will be provided on the exam. It would probably be helpful to memorize the units each symbol represents because it will be easier to do dimensional analysis and manipulate equations.
Sun Apr 22, 2018 9:22 pm
Forum: Properties of Light
Topic: still don't uderrsatnd what a photon is [ENDORSED]
Replies: 20
Views: 527
### Re: still don't uderrsatnd what a photon is[ENDORSED]
You just need to manipulate the equations and its easy to see the relationship between photons and momentum especially if you do dimensional analysis.
Sun Apr 15, 2018 8:46 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 5
Views: 301
### Balancing Chemical Reactions
Does anyone have any tips and tricks for quickly balancing equations?
Sun Apr 15, 2018 8:44 pm
Forum: Balancing Chemical Reactions
Topic: Help with homework problem L.39 [ENDORSED]
Replies: 2
Views: 227
### Re: Help with homework problem L.39[ENDORSED]
The total mass of tin oxide is: 28.35g-26.45g=1.90g Then you convert grams of Sn to moles of Sn and do the same thing for oxygen to get the molar ratio: 1.50g Sn x (1 mol Sn/118.71g Sn)=1.264 x10^-2 mol Sn (1.90-1.50)g O x (1 mol O/16.00 g O)=0.025 mol O Mole Ratio of Sn:O is 1:2 so the Empirical Fo...
Sun Apr 15, 2018 8:38 pm
Forum: SI Units, Unit Conversions
Topic: writing out conversions in one long line vs. steps
Replies: 16
Views: 805
### Re: writing out conversions in one long line vs. steps
I was taught to do it in one long line but it is important to write out what chemicals you are using when converting mass and moles. This is a great technique was trying to cancel things out
Fri Apr 06, 2018 1:27 pm
Forum: SI Units, Unit Conversions
Topic: Using units in calculations [ENDORSED]
Replies: 4
Views: 188
### Re: Using units in calculations[ENDORSED]
In addition to units I would also add what element or molecule the value is connected to, especially when dealing with moles.
Fri Apr 06, 2018 1:25 pm
Forum: Balancing Chemical Reactions
Topic: H.5: Balancing Equations
Replies: 6
Views: 493
### Re: H.5: Balancing Equations
I would also recommend making a chart. It is also important to remember that even if an equation is given to you in a problem, if there are no coefficients you need to make sure it is balanced. Even if there are coefficients it is important to double check.
Fri Apr 06, 2018 12:48 pm
Forum: Limiting Reactant Calculations
Topic: General Process [ENDORSED]
Replies: 3
Views: 223
### Re: General Process[ENDORSED]
Also it is helpful to convert the moles of the given reactants to the mass of the product you are looking for the limiting reactant because you can determine the limiting reactant and find the mass in one step. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8226557970046997, "perplexity": 3647.1775743999992}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655897707.23/warc/CC-MAIN-20200708211828-20200709001828-00485.warc.gz"} |
https://www.maths.cam.ac.uk/person/cpt39 | # Faculty of Mathematics
## Career
• 2017-date: Junior Research Fellow, Gonville & Caius College, University of Cambridge
• 2013-2017: PhD Student, DAMTP, University of Cambridge
• 2009-2013: BA/MMath, University of Cambridge
## Research
I am a member of the High Energy Physics group in the Department of Applied Mathematics and Theoretical Physics. My research interests involve various areas of field theory and string theory - I am currently working on the relationship between supersymmetric theories and non-relativistic, 2+1 dimensional condensed matter physics.
I completed my PhD, "BPS Approaches to Anyons, Quantum Hall States and Quantum Gravity", under the supervision of Professor David Tong in 2017.
## Publications
• N. Dorey, D. Tong, C. P. Turner, "A Matrix Model for WZW", 2016 [arXiv: 1604.05711]
• N. Dorey, D. Tong, C. P. Turner, "A Matrix Model for Non-Abelian Quantum Hall States", 2016 [arXiv: 1603.09688]
• N. Doroud, D. Tong, C. P. Turner, "On Superconformal Anyons", JHEP 1601 (2016) 138 [arXiv: 1511.01491]
• D. Tong, C. P. Turner, "Vortices and Monopoles in a Harmonic Trap", JHEP 1512 (2015) 098 [arXiv: 1508.01207]
• D. Tong, C. P. Turner, "The Quantum Hall Effect in Supersymmetric Chern-Simons Theories", Phys.Rev. B92 (2015) 23 235125 [arXiv: 1508.00580]
• D. Tong, C. P. Turner, "Quantum Dynamics of Supergravity on R3 x S1", JHEP 1412 (2014) 142 [arXiv: 1408.3418]
• H. S. Reall, A. A. H. Graham, C. P. Turner, "On algebraically special vacuum spacetimes in five dimensions", Class. Quant. Grav. 30 (2013) 055004 [arXiv: 1211.5957]. Selected as one of the CQC Highlights of 2012-13.
## Publications
Notes on 8 Majorana Fermions
D Tong, C Turner
– SciPost Physics Lecture Notes
(2020)
014
The quantum origins of non-topological vortices
C Turner
– Journal of High Energy Physics
(2020)
2020,
189
A web of 2d dualities: ${\bf Z}_2$ gauge fields and Arf invariants
A Karch, D Tong, C Turner
– SciPost Physics
(2019)
7,
007
Dualities in 2+1 Dimensions
C Turner
– Proceedings of XIV Modave Summer School in Mathematical Physics — PoS(Modave 2018)
(2019)
2018,
001
Hall viscosity in the non-Abelian quantum Hall matrix model
MF Lapa, C Turner, TL Hughes, D Tong
– Physical Review B
(2018)
98,
075133
Mirror symmetry and bosonization in 2d and 3d
A Karch, D Tong, C Turner
– Journal of High Energy Physics
(2018)
2018,
59
The conformal spectrum of non-Abelian anyons
N Doroud, D Tong, C Turner
– SciPost Physics
(2018)
4,
022
ADHM and the 4d quantum Hall effect
A Barns-Graham, N Dorey, N Lohitsiri, D Tong, C Turner
– Journal of High Energy Physics
(2018)
2018,
40
Non-abelian 3$D$ bosonization and quantum Hall states
Ð Radičević, D Tong, C Turner
– Journal of High Energy Physics
(2016)
2016,
67
Matrix model for non-Abelian quantum Hall states
N Dorey, D Tong, C Turner
– Physical Review B
(2016)
94,
085114
• 1 of 2
• >
## Research Group
High Energy Physics
B2.03
01223 330853 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.454224169254303, "perplexity": 17494.2279401054}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439738603.37/warc/CC-MAIN-20200810012015-20200810042015-00433.warc.gz"} |
http://mathbook.pugetsound.edu/doc/author-guide/html/topic-mathematics.html | ## Section6.8Mathematics
As mentioned in the overview, Section 3.5, we use syntax for mathematics. In order to allow for quality display in HTML, and other electronic formats, this limits us to the subsset of supported by the very capable MathJax Javascript library. Generally this looks like the amsmath package maintained by the American Mathematical Society at their AMS-LaTeX page. For a complete and precise list of what MathJax supports, see the MathJax Supported LaTeX commands page.
### Subsection6.8.1Inline Mathematics
Use the <m> to place variables or very short expressions within a sentence of a paragraph, the content of a <title>, a <cell> of a table, a footnote, or other similar locations of sentence-like text. You can't cross-reference this text, nor make a knowl with it. Though you can typically cross-reference a containing element.
Do not use -isms like \displaystyle to try to end-run the inline nature. It will just lead to poor results.
### Subsection6.8.2One-Line Display Mathematics
The <me> element can be used for longer expressions or a single equation. Typically you will get vertical separation above and below, and the contents will be centered. See below about concluding periods (and other punctuation), and alignment. The <men> variant will produce a numbered equation, and therefore with a provided @xml:id attribute, can be the target of a cross-reference (<xref>).
### Subsection6.8.3Multi-line Display Mathematics
We begin with a pure container, either <md> or <mdn>. The former numbers no lines, the latter numbers every line. Within the container, content, on a per-line basis, goes into a <mrow> element. You can think of <mrow> as being very similar to <me>. If you are tempted to put a \\ into an <mrow>, think twice.
On any given <mrow> you can place the @number attribute, with allowable values of yes and no. These will typically be used to override the behavior inherited by the container, but there is no harm if they are redundant. A given line of the display may be the target of a cross-reference, though the numbering flexibility means you can try (and fail) to target an unnumbered equation.
An <mrow> may have a @tag attribute in place of a @number attribute. This will create a “number” on the equation which is just a symbol. This is meant for situations where you do not want to use numbers, and the resulting cross-reference is “local.” In other words, the <xref> and its target are not far apart, such as maybe within the same <example> or the same <proof>. Allowable values for the attribute are: star, dstar, tstar, dagger, ddagger, tdagger, hash, dhash, thash, maltese, dmaltese, tmaltese. These are the names of symbols, with prefixes where the prefix d means “double”, and the prefix t means “triple”. Cross-references to these tagged equations happens in the usual way and should behave as expected. See Section 3.3 and Section 6.6 for more on cross-references.
### Subsection6.8.4Special Characters
The macros, \amp, \lt, and \gt are always available within these mathematics elements, so that you can avoid the special XML characters &, < and >. See Section 3.13 for this same information, but in the broader context of your entire document.
### Subsection6.8.5Text in Mathematics
Once in a while, you need a little bit of “regular” text within an expression and you do not want it to look like a product of a bunch of one-letter variables. Use the \text{} macro for these. Only. Other ways of switching out of math-mode and into some sort of “regular” text will appear inferior, and can raise errors in certain conversions.
• Do place surrounding spaces inside the \text{} macro.
• Do not place any mathematics inside the \text{} macro.
• Do not use the \mbox{} macro as a substitute.
• Do not use font-changing commands (e.g. \rm) as a substitute.
For example,
<me>f(x) = \begin{cases} x^2 \amp \text{if } x\gt 0\\
-7 \amp \text{otherwise} \end{cases}</me>
produces
\begin{equation*} f(x) = \begin{cases}x^2\amp\text{if }x\gt 0\\-7\amp\text{otherwise}\end{cases}\text{.} \end{equation*}
This example amply illustrates the use of macros for XML special characters (twice), appropriate use of the \text{} macro (twice), spaces in the \text{} macro (once), sentence-ending punctuation (see the source, the period is not inside the <me> element) and yes, we did think twice about the \\ (an exception to the rule).
### Subsection6.8.6Cross-References in Display Mathematics
A cross-reference is achieved with the <xref> element, see Section 3.3. You can place an <xref> inside a <mrow>, and remarkably, it will do the right thing. This is one of only two XML elements you can mix-in with syntax. A typical use is to provide a justification or explanation for a step in a proof, derivation, or simplification. And it works best with alignment, see below.
### Subsection6.8.7Alignment in Display Mathematics
Displayed mathematics is implemented with the AMS- align environment. Ampersands are used to control this, so use the \amp macro for these. The first ampersand in a line or row is an alignment point, typically a symbol, like an equality. The next ampersand is a column separator, then the next is an alignment point, then a column separator, then… The moral of the story is you should have $n$ alignment points, with $n-1$ column separators, for a total of $2n-1$ ampersands—always an odd number.
For example,
<md>
<mrow>A \amp = B \amp D \amp = E \amp \amp \text{Because}</mrow>
<mrow> \amp = C \amp \amp = F \amp \amp <xref ref="txo" /></mrow>
</md>
produces
\begin{align*} A \amp = B \amp D \amp = E \amp \amp\text{Because}\\ \amp = C \amp \amp = F \amp \amp\knowl{./knowl/txo.html}{\text{Table 6.6.3}}\text{.} \end{align*}
Sometimes you want several short equations on one line. Do not use <me>. Instead use a single <mrow> inside an <md>, and use alignment to spread them out evenly.
For multi-line display mathematics with no ampersands present, each line will be centered. This is implemented with the AMS- gather environment.
You can fool the alignment behavior by hiding all your ampersands in macro definitions, so there is the optional @alignment attribute for the <md> or <mdn> element, in order to force the right kind of alignment. Allowable values are gather, align, and alignat. The latter is similar to align, but no space is automatically provided between columns. You can leave it that way, or explicitly add your own. For example, this allows you to precisely arrange individual terms of a system of linear equations, especially when terms with zero coefficients are omitted. When using the alignat option PreTeXt tries to count ampersands to see how many columns you intend, since needs this number (we are not sure why). This detection can be fooled too, especially if you have something like a matrix with lots of ampersands for other purposes. So set the @alignat-columns attribute to the number of intended columns, if necessary.
### Subsection6.8.8Fill-In Blanks in Mathematics
The other mix-in XML element is <fillin> with an optional @characters attribute that takes an integer value. You will get a thin horizontal line, on the baseline, which can suggest to a reader that they should supply something within the surrounding mathematics. The attribute suggests the length of the line—experiment a bit, since it is not super-precise.
### Subsection6.8.9Page Breaks for Tall Display Mathematics
For print output, do nothing additional and will do its best to break your display between lines. You can turn this behavior off by setting the @break attribute on the <md> or <mdn> to the value no. Once you do this, you can then selectively allow a page break after a given <mrow> by setting the @break attribute on the <mrow> to the value yes.
These go in the <docinfo> section, wrapped in a <macros> element. Keep them simple—one or two arguments, and one-line definitions. This is not the place to be fancy, and not the place to try to end-run the structural aspects of PreTeXt. The idea is to define something like \adjoint{A} for the matrix A to be a superscript asterisk, and later you can change your mind and use a superscript dagger instead. Keep in the spirit of PreTeXt and use readable, semantic macros. For example, do not use \a{A} for the adjoint of A.
PreTeXt will use your macros correctly for print and for HTML, after erasing whitespace from the left margin, and stripping comments.
### Subsection6.8.11Punctuation After Display Math
If a chunk of displayed math concludes a sentence, then the sentence-ending punctuation should appear at the conclusion of the display. (And certainly not at the start of the first line after the display!) But do not author the punctuation within the mathematics element, put it afterwards, where it logically belongs.
More specifically, place a sentence-ending period (say) immediately after the closing of an <me>, <men>, <md>, or <mdn> element. PreTeXt will place the period in your output in the right place and in the right way. (By using 's \text{} macro, if you are curious to know the details.) Here is an example. The XML source
<md>
<mrow>(a+b)^2</mrow>
</md>. Now...
will render as
\begin{gather*} (a+b)^2\text{.} \end{gather*}
Now…
This all applies more generally to clause-ending punctuation, such as a comma. Take notice of the requirement that the punctuation must be immediately after the closing tag of the math element, otherwise it will not migrate properly. For example, do not interrupt the flow with whitespace, or an XML comment, or anything else.
Here is a technical subtlety that will demonstrate some of the inner machinery of PreTeXt and our conversions. In your work, locate a theorem that has some numbered display mathematics (mdn) which is at the end of a sentence, and which you have authored as described above. In HTML output, test a cross-reference (xref) to the theorem and you will see the period for the end of the sentence at the end of the display, where it should be. Now test a cross-reference (xref) to one of the numbered equations. First, the knowl will contain the entire display, to provide context, but it also will not contain the period, since the rest of the sentence is not in the knowl and so the period is not necessary.
Generally, you cannot add additional packages for use within mathematics. The exception is a package with support available optionally within MathJax. And it must have the same name as its normal version. Then set a docinfo/latex-preamble/package element to be the common name of the package. (The cancel package is one such example.)
There are two existing additional options, which we might want to remove some day for technical reasons. Macros from the extpfeil extensible arrows package are availble by default, and an \sfrac{}{} macro is available for appealing inline “slanted fractions.” | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7284302115440369, "perplexity": 2450.830715448058}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583658662.31/warc/CC-MAIN-20190117000104-20190117022104-00068.warc.gz"} |
http://jahla.hatef.ac.ir/article_130536.html | # State hyper BE-algebras
Document Type : Original Article
Authors
1 School of Science, Xi'an Aeronautical University, Xi'an, 710077, China
2 Department mathematics, northwest university, xian, china
Abstract
In this paper, state operators on hyper BE-algebras (correspondingly, state hyper BE-algebras) are introduced and studied. State hyper filters are introduced and generated state hyper filters are represented in state hyper BE-algebras. Also, maximal (prime) state hyper filters are characterised and the relations between state maximal hyper filters and state prime hyper filters are discussed. Moreover, some related results of state (compatible) hyper congruence are obtained. Especially, it follows that there is an isotone bijection between all state strong regular $\circ$-reflexive hyper filter $\mathcal{F}_s(H,\xi)$ and all state compatible hyper congruence $\mathcal{C}_s(H,\xi)$ on state commutative transitive RD-hyper BE-algebra $(H,\xi)$.
Keywords | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7354930639266968, "perplexity": 9393.790738219048}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320300010.26/warc/CC-MAIN-20220116180715-20220116210715-00625.warc.gz"} |
https://www.degruyter.com/view/j/cdbme.2015.1.issue-1/cdbme-2015-0019/cdbme-2015-0019.xml | Show Summary Details
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# Current Directions in Biomedical Engineering
### Joint Journal of the German Society for Biomedical Engineering in VDE and the Austrian and Swiss Societies for Biomedical Engineering
Editor-in-Chief: Dössel, Olaf
Editorial Board: Augat, Peter / Buzug, Thorsten M. / Haueisen, Jens / Jockenhoevel, Stefan / Knaup-Gregori, Petra / Kraft, Marc / Lenarz, Thomas / Leonhardt, Steffen / Malberg, Hagen / Penzel, Thomas / Plank, Gernot / Radermacher, Klaus M. / Schkommodau, Erik / Stieglitz, Thomas / Urban, Gerald A.
2 Issues per year
Open Access
Online
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2364-5504
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Volume 1, Issue 1
# Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
André Bideaux
• Corresponding author
• Karlsruhe Institute of Technology, Institute for Information Processing Technologies (ITIV), Engesserstr. 5, D-76131 Karlsruhe, Germany
• Email
• Other articles by this author:
/ Bernd Zimmermann
• Karlsruhe Institute of Technology, Institute for Information Processing Technologies (ITIV), Engesserstr. 5, D-76131 Karlsruhe, Germany
• Other articles by this author:
/ Stefan Hey
• Karlsruhe Institute of Technology, Institute for Information Processing Technologies (ITIV), Engesserstr. 5, D-76131 Karlsruhe, Germany
• Other articles by this author:
/ Wilhelm Stork
• Karlsruhe Institute of Technology, Institute for Information Processing Technologies (ITIV), Engesserstr. 5, D-76131 Karlsruhe, Germany
• Other articles by this author:
Published Online: 2015-09-12 | DOI: https://doi.org/10.1515/cdbme-2015-0019
## Abstract
Bluetooth Low Energy (BLE) has reduced the energy consumption for sensor nodes drastically. One major reason for this improvement is a non-continuous connection between the nodes. But this causes also a nondeterministic data transmission time. Most synchronization protocols are influenced by this characteristic, with the result of less accuracy. In wireless body sensor networks this accuracy is often of vital importance. Therefore this paper evaluates different synchronization principles customized for BLE.
For the evaluation measurements we used two BLE modules connected to one micro controller. This setup allowed us to calculate the error directly for the different principles. First we measured the send-receive time as a reference which influences most synchronization protocols. This time is directly affected by random transmission delays of BLE. Second we used the time difference between receiving and acknowledging a message as principle (A). The last principle (B) can only be used between nodes that use BLE that don’t require a constant connection, because it needs to connect and disconnect the nodes. After a new connection the “connected” events occur in the BLE nodes almost at the same time and can be used for synchronization. The reference measurement showed the worst results. The average delay was 4.76 ms with a standard deviation of 2.32 ms. Principle (A) showed average delays of 7.51 ms, which was almost exactly 1 connection interval in our setup. The standard deviation was 0.41 ms. Principle (B) showed the best results with an average time difference of 39.92 μs and a standard deviation of 14.19 μs
The results showed that with the principles (A) and (B) the synchronization of nodes can be highly improved compared to the reference. In future we will test the principles with synchronization protocols in real sensor nodes also with respect to the processor load.
## 1 Introduction
Biomedical monitoring systems rely often on multi-sensor data fusion. The main idea is that the recorded signals together contain more information than all signals individually. E.g. if we have an electrocardiogram (ECG) and a photoplethysmogram (PPG) we can measure the time difference between the electrical stimulation of the heart and the pulse wave reaching the PPG sensor. This parameter is called pulse transit time (PTT) and has a linear connection with blood pressure [1] To get this additional information synchronization between the sensors is of vital importance. E.g. for calculating the PTT a synchronization accuracy of at least 1 ms is required [2].
In wired networks this accuracy is easy to reach with a common clock or by exchanging time stamps. But to monitor patients out of hospital during every day activities small wireless sensors are the best solution. This distributed sensors nodes in wireless networks have no common clock. Hence the local time of each sensor can drift, especially during measurements over a day or longer. Even in laboratory conditions with constant temperatures, we measured a drift of over 1 s per day between sensors using crystal oscillators.
In [3] different synchronization methods for wireless networks are described. All of the methods rely either on deterministic times for message exchanges or on common events. One of the most common wireless communication standards for low power sensors is Bluetooth Low Energy (BLE). BLE reduces the energy consumption for sensor nodes drastically compared to other wireless standards. One major reason for this is a non-continuous connection between the nodes. The connection between the nodes after establishing is divided into connection intervals (CI), as shown in Figure 1. If there is nothing to communicate the module will fall in a sleep mode until the next connection interval starts and the communication gets reinitialized. This sleep mode causes a non-deterministic delay between the incoming write command and the actual transition.
The CI length is set in the initialization phase and can be between 7.5 ms and 4 s. Hence there is at least a random message delay between 0 and 7.5 ms in a BLE message transfer. If the BLE module is busy the delay can be even longer than one CI.
Figure 1
Connection intervals for BLE nodes.
One of the most popular synchronization protocols the Network Time Protocol (NTP) would suffer directly from this characteristic. Figure 2 describes the principle of NTP synchronization. Node A sends a request to node B and takes the time stamp T1. Node B answers with two time stamps R1 and T2. When the message arrives at node A it takes the last time stamp R2 and calculates the offset as follows: $Offset=(R1−T1)+(R2−T2)2$
Figure 2
Exchange of timestamps in the Network Time Protocol.
To find more appropriate synchronization protocols that can fulfil the requirements of most wireless biomedical sensor networks; this paper investigates different principles to synchronize BLE nodes.
## 2 Synchronization principles
As test setup we used the EFM32TG [5] microcontroller starter kit and connected two BLE112 [6] Bluetooth modules via UART. The microcontroller’s real time clock runs with 32.768 kHz and the UARTs have a baud rate of 115200 Baud. The microcontroller takes the time stamps for the different events of the two BLE modules. The fact that we use only one microcontroller and time base with two Blue-tooth modules lets us calculate the error directly.
As a reference we measured the send-receive delay with a CI of 7.5 ms. Then we investigated two different use cases. The first is two BLE nodes with an established connection and a CI of 7.5 ms. The modules communicate regularly and we use the receive-acknowledge delay to measure the time difference (Principle (A). In the second use case we have two nodes with no active communication but the possibility to establish it for synchronization purposes. In this case we measured the time difference between the “connected” events that occur on both nodes after establishing a new connection (Principle (B).
## 2.1 Reference send receive delay
As a reference we measured the time stamps of received and transmitted data. The non-deterministic character of the BLE data transmission will lead to an additional delay to the one caused by the physical transmission. Figure 3 illustrates this process. The data is send with a write command to the first BLE module and is then transmitted to the second BLE module at the start of the next connection event, from where it is forwarded to the second microcontroller.
Figure 3
## 2.2 Principle (A) receive acknowledge delay
For principle (A) we used an acknowledgement for attribute writing with the Generic Attribute Profile (GATT). The random time delay between the sending and receiving is irrelevant for calculating the time difference between receiving and acknowledgement. The time difference between T1 and T2 shown in Figure 4 should be a multiple of the CI, when we assume all messages are exchanged at its beginning. This could be used in synchronization protocols.
Figure 4
## 2.3 Principle (B) connection events
In principle (B) the two sensor nodes have to establish a connection to communicate. This initiation process leads to the “connected” event on both nodes. This event should arrive almost at the time and can be used as common time reference to synchronize the sensors. Figure 5 describes this initialization process and the time stamps we used for the synchronization.
Figure 5
Connection initialization between BLE modules.
## 3.1 Reference results
The reference measurements are shown in Figure 6. The delay is mostly distributed within the range of one CI. Values below 1 ms do not exist. This is probably related to the time the BLE112 module needs to process the write command. The average time difference is 4.76 ms. If we subtract the 1 ms processing time from this value, we get 3.76 ms, which is about half the CI we used. The standard deviation is 2.32 ms. Hence a synchronization of 1 ms accuracy is difficult and can only be reached by improving it statistically with multiple repetitions.
Figure 6
Error for NTP method (CI = 7.5 ms; data points 1024).
## 3.2 Results for principle (A)
In Principle (A) we calculated the delay between receiving and acknowledging. As shown in Figure 7 the average time to acknowledge the reception is 7.51 ms, which is almost exactly 1 CI. The standard deviation of 0.41 ms shows that synchronization between two nodes with an accuracy of 1 ms or better is possible.
Figure 7
Time between message and acknowledgement receiving in principle (A) (CI = 7.5 ms; data points 1024).
## 3.3 Results for principle (B)
In principle (B) we calculated the time difference between the “connected” events that occur when the connection gets established.
Figure 8 shows this time difference. It is most of the time only one clock step (30.52 ms). The communication initiator always detects the signal first. This is most likely due to its role. The average delay between the connection events was 39.92 μs with a standard deviation of 14.19 μs. With this principle, synchronizations even more precise than 1 ms can be reached.
Figure 8
Time between the connection events of both BLE modules in principle (B) (data points 672).
## 4 Conclusion
We tested two different synchronization principles for BLE nodes against a reference that is used in most synchronization protocols. As reference we used the time difference between sending and receiving messages. The results show that it is possible to synchronize nodes with this principle, but the standard deviation of 2.32 ms makes it difficult to reach accuracies above our requirement of 1 ms. Principle (A) that uses the receive acknowledge time difference showed much better results with a standard deviation of 0.41 ms. The best result of 14.19 μs standard deviation was established with principle (B). This method can only be used when the participating nodes can be connected and disconnected at will. It uses the “connected” event that occurs on both BLE modules after establishing a connection.
In future we want to test the synchronization principles with protocols in real sensor nodes. The micro controller we used for this test had no processor load except the synchronization. Hence tests under normal operation conditions are essential to evaluate the accuracy in the field.
## References
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H. P. Boll, Mobile Überwachung der Funktionalität des kardiovaskulären Systems – Konzepte und Simulationen. Institut für Technik der Informationsverarbeitung, Universität Karlsruhe, 2008. Google Scholar
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M. Nakamura, J. Nakamura, G. Lopez, M. Shuzo, and I. Yamada, “Collaborative processing of wearable and ambient sensor system for blood pressure monitoring.,” Sensors (Basel)., vol. 11, no. 7, pp. 6760–70, Jan. 2011. Google Scholar
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B. Sundararaman, U. Buy, and A. D. Kshemkalyani, “Clock synchronization for wireless sensor networks: A survey,” Ad Hoc Networks, vol. 3, pp. 281–323, 2005. Google Scholar
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B. Sig, “Bluetooth Specification Version 4.2,” History, vol. 0, 2014.Google Scholar
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Bluegiga Technologies, “BLE112 Version 1.45.” Bluegiga Technologies, 2014. Google Scholar
Published Online: 2015-09-12
Published in Print: 2015-09-01
#### Author’s Statement
Conflict of interest: Authors state no conflict of interest. Material and Methods: Informed consent: Informed consent has been obtained from all individuals included in this study. Ethical approval: The research related to human use has been complied with all the relevant national regulations, institutional policies and in accordance the tenets of the Helsinki Declaration, and has been approved by the authors’ institutional review board or equivalent committee.
Citation Information: Current Directions in Biomedical Engineering, Volume 1, Issue 1, Pages 73–76, ISSN (Online) 2364-5504,
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© 2015 by Walter de Gruyter GmbH, Berlin/Boston. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 1, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.44664639234542847, "perplexity": 2143.05927558296}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257645830.10/warc/CC-MAIN-20180318165408-20180318185408-00335.warc.gz"} |
http://libros.duhnnae.com/2017/jul8/15014021866-Efficient-prime-counting-and-the-Chebyshev-primes.php | Efficient prime counting and the Chebyshev primes
Efficient prime counting and the Chebyshev primes - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.
1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies 2 Télécom ParisTech
Abstract : The function $\epsilonx=\mbox{li}x-\pix$ is known to be positive up to the very large Skewes- number. Besides, according to Robin-s work, the functions $\epsilon {\theta}x=\mbox{li}\thetax-\pix$ and $\epsilon {\psi}x=\mbox{li}\psix-\pix$ are positive if and only if Riemann hypothesis RH holds the first and the second Chebyshev function are $\thetax=\sum {p \le x} \log p$ and $\psix=\sum {n=1}^x \Lambdan$, respectively, $\mbox{li}x$ is the logarithmic integral, $\mun$ and $\Lambdan$ are the Möbius and the Von Mangoldt functions. Negative jumps in the above functions $\epsilon$, $\epsilon {\theta}$ and $\epsilon {\psi}$ may potentially occur only at $x+1 \in \mathcal{P}$ the set of primes. One denotes $j p=\mbox{li}p-\mbox{li}p-1$ and one investigates the jumps $j p$, $j {\thetap}$ and $j {\psip}$. In particular, $j p1$ for \$p
Autor: Michel Planat - Patrick Solé -
Fuente: https://hal.archives-ouvertes.fr/
DESCARGAR PDF | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9687797427177429, "perplexity": 1841.0281318860666}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891815812.83/warc/CC-MAIN-20180224132508-20180224152508-00657.warc.gz"} |
https://quantumcomputing.stackexchange.com/questions/21755/does-a-photonic-quantum-computer-control-a-single-photon | # Does a photonic quantum computer control a single photon?
Does a photonic quantum computer control a single photon and use it to represent a single qubit?
I think ion trapped quantum computers use a single ion to represent a qubit. I would like to know how a photonic quantum computer represents each qubit.
There are various ways in which one or multiple photons can be used to encode qubits.
Potentially the most widely used encoding (at least when quantum communication is assumed to within the scope of 'quantum computing' for this question) is the polarization-encoded photon. Here, a single photon is used as a qubit, where two orthogonal polarization directions are used as the computational basis of the encoded qubit.
Another often used encoding within communication tasks is the 'time-bin' encoding. Here, the qubit can be regarded as a window in time during which a single photon can exist. The $$|0\rangle$$ state is then encoded as the photon being (roughly speaking) within the first half of the window, and the $$|1\rangle$$ state is encoded as the photon being in the latter half of the window. Oftentimes there are more stringent windows instead of a 'full half' for the states.
Turning more to proper 'quantum computers', photons can be used in various ways to encode qubits. Another widely used single photon encoding is the so-called 'rail'-encoding when talking about integrated photonics (i.e. 'photons on a chip'). Here, there are two waveguides engraved into a chip through which a photon can travel. The qubit's computational basis is encoded as the photon being in the one or the other waveguide.
It is, in principle, even possible to use both the polarization and the 'rail' encoding together at the same time, to encode two qubits into a single photon - this is area of active research. This is sometimes called 'dual-rail' encoding, compared to the 'normal' rail encoding described above, which is then known as 'single-rail' encoding.
There exist, however, also photonic quantum computers (at least on paper) that do not use a single photon to encode a qubit. As photons are bosons, they can be used to create bosonic codes like GKP, cat or binomial codes, although most research for implementations of these codes is being performed for harmonic oscillators in, for instance, superconductor devices.
If we focus on computation, there are various ways of implementing gates. Relatively agnostic of the encoding (as long as its single-photon) is the KLM protocol, which uses combinations of beam splitters and phase shift materials (which fall both within the scope of linear optics) to implement single-qubit gates. Two qubit gates (namely, a conditional sign flip) are also implemented by linear elements, but the big drawback of this method is that it is non-deterministic.
Focusing specifically on rail encodings, one can also have non-linear interactions between the two modes by bringing the two waveguides together in a birefringent (?) material. This method also allows to implement two-qubit gates, by bringing the $$|1\rangle$$ waveguides of both qubits together in a similar fashion. I am not at all an expert on this matter, however.
• Thank you. For quantum computers, not quantum communication, when using a single photo to encode a qubit, how does two photons do COMPUTING ? Nov 1 at 18:51
• @david I've added a couple of thoughts, although I'm not very well versed on the matter unfortunately.
– JSdJ
Nov 3 at 12:38
• thank you for the explanation. Nov 3 at 23:02 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 3, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8023490905761719, "perplexity": 706.2395856285267}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964363301.3/warc/CC-MAIN-20211206133552-20211206163552-00331.warc.gz"} |
https://proceedings.neurips.cc/paper/2020/hash/1bd413de70f32142f4a33a94134c5690-Abstract.html | #### Authors
Alessandro Epasto, Mohammad Mahdian, Vahab Mirrokni, Emmanouil Zampetakis
#### Abstract
A soft-max function has two main efficiency measures: (1) approximation - which corresponds to how well it approximates the maximum function, (2) smoothness - which shows how sensitive it is to changes of its input. Our goal is to identify the optimal approximation-smoothness tradeoffs for different measures of approximation and smoothness. This leads to novel soft-max functions, each of which is optimal for a different application. The most commonly used soft-max function, called exponential mechanism, has optimal tradeoff between approximation measured in terms of expected additive approximation and smoothness measured with respect to Renyi Divergence. We introduce a soft-max function, called piece-wise linear soft-max, with optimal tradeoff between approximation, measured in terms of worst-case additive approximation and smoothness, measured with respect to l_q-norm. The worst-case approximation guarantee of the piece-wise linear mechanism enforces sparsity in the output of our soft-max function, a property that is known to be important in Machine Learning applications Martins et al. 16, Laha et al. 18 and is not satisfied by the exponential mechanism. Moreover, the l_q-smoothness is suitable for applications in Mechanism Design and Game Theory where the piece-wise linear mechanism outperforms the exponential mechanism. Finally, we investigate another soft-max function, called power mechanism, with optimal tradeoff between expected multiplicative approximation and smoothness with
respect to the Renyi Divergence, which provides improved theoretical and practical results in differentially private submodular optimization. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9644556045532227, "perplexity": 1109.0462698763697}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046154320.56/warc/CC-MAIN-20210802110046-20210802140046-00142.warc.gz"} |
https://en.wanweibaike.com/wiki-Batoni_(title) | # Batoni (title)
Batoni (Georgian: ბატონი) is a Georgian word for "lord", or "master". It is derived from patroni (პატრონი), the earlier term of similar meaning, and appears in common usage in the 15th century.
• In Georgian feudal hierarchy, "batoni" may denote the supreme suzerain (i.e., monarch), seigneur, or any secular or clerical who owned qma, i.e., "slave" or "serf". The word sometimes appears as a part of the royal and nobiliary titulature. For example, the title of the Princes of Mukhrani was batoni (Mukhran-batoni), and the early kings of Kakheti were likewise referred to by that title in some Georgian sources.[1][2][3]
• In modern usage, batoni is an honorific used for a man, an equivalent of both Mr. and sir. The equivalent female title is k'albatoni (ქალბატონი). It can be used with the full name as well as either the last or first name. When addressing someone directly, the word is used in a vocative case (k'al)batono ([ქალ]ბატონო), and precedes either the first name (more commonly) or the last name, but it can also be used by itself in direct address.[4]
## References
1. ^ Toumanoff, Cyril (1949–51). The Fifteenth-Century Bagratids and the Institution of Collegial Sovereignty in Georgia. Traditio 7: 216.
2. ^ Jones, Stephen F. (2005), Socialism in Georgian Colors: The European Road to Social Democracy, 1883-1917, p. 195. Harvard University Press, ISBN 0-674-01902-4.
3. ^ Suny, Ronald Grigor (1994), The Making of the Georgian Nation, pp. 42-3. Indiana University Press, ISBN 0-253-20915-3
4. ^ Braun, Friederike (1998), Terms of address: problems of patterns and usage in various languages and cultures, pp. 106-113. Walter de Gruyter, ISBN 0-89925-432-2 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8628152012825012, "perplexity": 10631.605267623469}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487649688.44/warc/CC-MAIN-20210619172612-20210619202612-00552.warc.gz"} |
https://labs.tib.eu/arxiv/?author=S.%20Koenig | • ### Planck's dusty GEMS. IV. Star formation and feedback in a maximum starburst at z=3 seen at 60-pc resolution(1704.05853)
July 6, 2017 astro-ph.GA
We present an analysis of high-resolution ALMA interferometry of CO(4-3) line emission and dust continuum in the "Ruby" (PLCK_G244.8+54.9), a bright, gravitationally lensed galaxy at z = 3.0 discovered with the Planck all-sky survey. The Ruby is the brightest of Planck's Dusty GEMS, a sample of 11 of the brightest gravitationally lensed high-redshift galaxies on the extragalactic sub-mm sky. We resolve the high-surface-brightness continuum and CO line emission of the Ruby in several extended clumps along a partial, nearly circular Einstein ring with 1.4" diameter around a massive galaxy at z = 1.5. Local star-formation intensities are up to 2000 M$_{\odot}$ yr$^{-1}$ kpc$^{-2}$, amongst the highest observed at high redshift, and clearly in the range of maximal starbursts. Gas-mass surface densities are a few $\times$ 10$^4$ M$_{\odot}$ pc$^{-2}$. The Ruby lies at, and in part even above, the starburst sequence in the Schmidt-Kennicutt diagram, and at the limit expected for star formation that is self-regulated through the kinetic energy injection from radiation pressure, stellar winds, and supernovae. We show that these processes can also inject sufficient kinetic energy and momentum into the gas to explain the turbulent line widths, which are consistent with marginally gravitationally bound molecular clouds embedded in a critically Toomre-stable disk. The star-formation efficiency is in the range 1-10% per free-fall time, consistent with the notion that the pressure balance that sets the local star-formation law in the Milky Way may well be universal out to the highest star-formation intensities. AGN feedback is not necessary to regulate the star formation in the Ruby, in agreement with the absence of a bright AGN component in the infrared and radio regimes.
• ### Planck's Dusty GEMS. III. A massive lensing galaxy with a bottom-heavy stellar initial mass function at z=1.5(1703.02984)
March 8, 2017 astro-ph.GA
We study the properties of the foreground galaxy of the Ruby, the brightest gravitationally lensed high-redshift galaxy on the sub-millimeter sky as probed by the Planck satellite, and part of our sample of Planck's Dusty GEMS. The Ruby consists of an Einstein ring of 1.4" diameter at z = 3.005 observed with ALMA at 0.1" resolution, centered on a faint, red, massive lensing galaxy seen with HST/WFC3, which itself has an exceptionally high redshift, z = 1.525 $\pm$ 0.001, as confirmed with VLT/X-Shooter spectroscopy. Here we focus on the properties of the lens and the lensing model obtained with LENSTOOL. The rest-frame optical morphology of this system is strongly dominated by the lens, while the Ruby itself is highly obscured, and contributes less than 10% to the photometry out to the K band. The foreground galaxy has a lensing mass of (3.70 $\pm$ 0.35) $\times$ 10$^{11}$ M$_{\odot}$. Magnification factors are between 7 and 38 for individual clumps forming two image families along the Einstein ring. We present a decomposition of the foreground and background sources in the WFC3 images, and stellar population synthesis modeling with a range of star-formation histories for Chabrier and Salpeter initial mass functions (IMFs). Only the stellar mass range obtained with the latter agrees well with the lensing mass. This is consistent with the bottom-heavy IMFs of massive high-redshift galaxies expected from detailed studies of the stellar masses and mass profiles of their low-redshift descendants, and from models of turbulent gas fragmentation. This may be the first direct constraint on the IMF in a lens at z = 1.5, which is not a cluster central galaxy.
• ### Planck's Dusty GEMS. II. Extended [CII] emission and absorption in the Garnet at z=3.4 seen with ALMA(1610.01169)
Oct. 4, 2016 astro-ph.GA
We present spatially resolved ALMA [CII] observations of the bright (flux density S=400 mJy at 350 microns), gravitationally lensed, starburst galaxy PLCK G045.1+61.1 at z=3.427, the "Garnet". This source is part of our set of "Planck's Dusty GEMS", discovered with the Planck's all-sky survey. Two emission-line clouds with a relative velocity offset of ~600 km/s extend towards north-east and south-west, respectively, of a small, intensely star-forming clump with a star-formation intensity of 220 Msun/yr/kpc^2, akin to maximal starbursts. [CII] is also seen in absorption, with a redshift of +350 km/s relative to the brightest CO component. [CII] absorption has previously only been found in the Milky Way along sightlines toward bright high-mass star-forming regions, and this is the first detection in another galaxy. Similar to Galactic environments, the [CII] absorption feature is associated with [CI] emission, implying that this is diffuse gas shielded from the UV radiation of the clump, and likely at large distances from the clump. Since absorption can only be seen in front of a continuum source, the gas in this structure can definitely be attributed to gas flowing towards the clump. The absorber could be part of a cosmic filament or merger debris being accreted onto the galaxy. We discuss our results also in light of the on-going debate of the origin of the [CII] deficit in dusty star-forming galaxies.
• ### Planck's Dusty GEMS: Gravitationally lensed high-redshift galaxies discovered with the Planck survey(1506.01962)
June 5, 2015 astro-ph.GA
We present an analysis of 11 bright far-IR/submm sources discovered through a combination of the Planck survey and follow-up Herschel-SPIRE imaging. Each source has a redshift z=2.2-3.6 obtained through a blind redshift search with EMIR at the IRAM 30-m telescope. Interferometry obtained at IRAM and the SMA, and optical/near-infrared imaging obtained at the CFHT and the VLT reveal morphologies consistent with strongly gravitationally lensed sources. Additional photometry was obtained with JCMT/SCUBA-2 and IRAM/GISMO at 850 um and 2 mm, respectively. All objects are bright, isolated point sources in the 18 arcsec beam of SPIRE at 250 um, with spectral energy distributions peaking either near the 350 um or the 500 um bands of SPIRE, and with apparent far-infrared luminosities of up to 3x10^14 L_sun. Their morphologies and sizes, CO line widths and luminosities, dust temperatures, and far-infrared luminosities provide additional empirical evidence that these are strongly gravitationally lensed high-redshift galaxies. We discuss their dust masses and temperatures, and use additional WISE 22-um photometry and template fitting to rule out a significant contribution of AGN heating to the total infrared luminosity. Six sources are detected in FIRST at 1.4 GHz. Four have flux densities brighter than expected from the local far-infrared-radio correlation, but in the range previously found for high-z submm galaxies, one has a deficit of FIR emission, and 6 are consistent with the local correlation. The global dust-to-gas ratios and star-formation efficiencies of our sources are predominantly in the range expected from massive, metal-rich, intense, high-redshift starbursts. An extensive multi-wavelength follow-up programme is being carried out to further characterize these sources and the intense star-formation within them.
• A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.
• ### Simultaneous NIR/sub-mm observation of flare emission from SgrA*(0811.2753)
Nov. 17, 2008 astro-ph
We report on a successful, simultaneous observation and modeling of the sub-millimeter to near-infrared flare emission of the Sgr A* counterpart associated with the super-massive black hole at the Galactic center. Our modeling is based on simultaneous observations that have been carried out on 03 June, 2008 using the NACO adaptive optics (AO) instrument at the ESO VLT and the LABOCA bolometer at the APEX telescope. Inspection and modeling of the light curves show that the sub-mm follows the NIR emission with a delay of 1.5+/-0.5 hours. We explain the flare emission delay by an adiabatic expansion of the source components.
• ### An evolving hot spot orbiting around Sgr A*(0810.0138)
Oct. 1, 2008 astro-ph
Here we report on recent near-infrared observations of the Sgr A* counterpart associated with the super-massive ~ 4x10^6 M_sun black hole at the Galactic Center. We find that the May 2007 flare shows the highest sub-flare contrast observed until now, as well as evidence for variations in the profile of consecutive sub-flares. We modeled the flare profile variations according to the elongation and change of the shape of a spot due to differential rotation within the accretion disk.
• ### Coordinated multi-wavelength observations of Sgr A*(0810.0168)
Oct. 1, 2008 astro-ph
We report on recent near-infrared (NIR) and X-ray observations of Sagittarius A* (Sgr A*), the electromagnetic manifestation of the ~4x10^6 solar masses super-massive black hole (SMBH) at the Galactic Center. The goal of these coordinated multi-wavelength observations is to investigate the variable emission from Sgr A* in order to obtain a better understanding of the underlying physical processes in the accretion flow/outflow. The observations have been carried out using the NACO adaptive optics (AO) instrument at the European Southern Observatory's Very Large Telescope (July 2005, May 2007) and the ACIS-I instrument aboard the Chandra X-ray Observatory (July 2005). We report on a polarized NIR flare synchronous to a 8x1033 erg/s X-ray flare in July 2005, and a further flare in May 2007 that shows the highest sub-flare to flare contrast observed until now. The observations can be interpreted in the framework of a model involving a temporary disk with a short jet. In the disk component flux density variations can be explained due to hot spots on relativistic orbits around the central SMBH. The variations of the sub-structures of the May 2007 flare are interpreted as a variation of the hot spot structure due to differential rotation within the disk.
• ### Coordinated mm/sub-mm observations of Sagittarius A* in May 2007(0810.0177)
Oct. 1, 2008 astro-ph
At the center of the Milky Way, with a distance of ~8 kpc, the compact source Sagittarius A* (SgrA*) can be associated with a super massive black hole of ~4x10^6 solar masses. SgrA* shows strong variability from the radio to the X-ray wavelength domains. Here we report on simultaneous NIR/sub-millimeter/X-ray observations from May 2007 that involved the NACO adaptive optics (AO) instrument at the European Southern Observatory's Very Large Telescope, the Australian Telescope Compact Array (ATCA), the US mm-array CARMA, the IRAM 30m mm-telescope, and other telescopes. We concentrate on the time series of mm/sub-mm data from CARMA, ATCA, and the MAMBO bolometer at the IRAM 30m telescope. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9053936004638672, "perplexity": 3215.575140377076}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141747774.97/warc/CC-MAIN-20201205104937-20201205134937-00063.warc.gz"} |
https://openor.blog/post/xkcd-2165/ | # xkcd-2165
## Generation divides, the news, Parliament
I can’t find the one I’m thinking of that pokes fun at newscasters being confused that non-boomers are getting elected. Today’s news on a Lib Dem MP coming out as pansexual had an article on BBC that was frankly confused about some of the main terms and the trans* umbrella. This is knowledge that could act as a shibboleth in my social bubble, so I wondered if this was a generational thing.
Wikipedia believes Layla Moran was born 1982, so let’s say Gen X. The natural question then is the age of every other MP.
The evil thing to do would be to scrape Wikipedia for each MPs age. This is explicitly against Wiki’s terms of service, but Wiki are nice and have provided Wikidata which means that it’s fairly easy to grab the current set of MPs, their names and their DOB. (Seriously, click the link, the query is built into the link.)
mp_dob <- read_csv(here::here("/static/data/Wiki/MP DOB.csv"))
mp_dob %>%
ggplot(aes(x=date_of_birth)) + geom_density() + ggthemes::theme_tufte() +
ggtitle("Density plot of dates of birth of current MPs")
mp_dob %>%
ggplot( aes(y=date_of_birth)) + geom_boxplot() + coord_flip() +
ggthemes::theme_tufte() +
ggtitle("Boxplot of same")
So from the graphs, about 50% of MPs are Boomers, but we’d have to be fuzzy on the boundary to call that!
mp_dob %>%
summarise(median date of birth = median(date_of_birth, na.rm = T)) %>%
knitr::kable()
median date of birth
1968-01-04 12:00:00
Slightly to the right of some of the boundaries of Boom.
mp_dob %>%
mutate(generation = case_when(
date_of_birth < ymd("1965-1-1") ~ "Boomer",
date_of_birth < ymd("1985-1-1") ~ "Gen X",
date_of_birth < ymd("2000-1-1") ~ "Milennial",
TRUE ~ "UNKNOWN"
)) %>%
ggplot(aes(x=generation)) + geom_bar() + ggthemes::theme_tufte()
The Unknowns are quite big, but Gen X almost has a majority in the Commons.
## Conclusion
Gen X are reasonably justified in feeling like the generation that the media have forgotten.
I’m going to come back to this to look at how many PMs or Cabinet Ministers are/have been PPE @ Oxbridge grads, or maybe Etonians. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.28096386790275574, "perplexity": 7378.404619829303}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875144708.87/warc/CC-MAIN-20200220070221-20200220100221-00507.warc.gz"} |
https://www.physicsforums.com/threads/quantum-field-theory-profound-insight-antiparticles.900572/ | # A Quantum Field theory profound insight antiparticles
1. Jan 16, 2017
### binbagsss
Hi,
I have recently began studying quatum field theory and have just seen how the quantization of the complex scalar field, noting that there is invariance of the action under a phase rotation shows the existence of antiparticles.
I just have a couple of questions, apologies in advance if they are stupid:
- I'm after some more physical intuition on the phase rotations? I can't find much in a google
- Probably a stupid question: are there any other field types with other in variances that demonstrate the existence of antiparticles in the same way?
Many thanks
2. Jan 16, 2017
### Staff: Mentor
Can you give a reference?
3. Jan 17, 2017
### binbagsss
is it incorrect?
4. Jan 17, 2017
### stevendaryl
Staff Emeritus
What you may thinking of is this:
• From the Lagrangian of the complex scalar field, you can use Noether's theorem to derive a conserved current.
• This current, unlike that of the Schrodinger equation, is not always positive.
• So it cannot be interpreted as a particle probability density.
• But it can be interpreted as a charge density, with contributions from both negatively charged and positively charged particles.
5. Jan 17, 2017
### vanhees71
Any useful QFT textbook is a reference.
The line of argument roughly goes like this: To define a Poincare covariant local (micro causal) QFT you need a combination of positive and negative-frequency solution of free-field equations of motion. Here local means that you have field operators that transform under Poincare transformations (represented by unitary representations of the covering group of the proper orthochronous Lorentz group) as their classical pendants, i.e., for a scalar field
$$\hat{U}(\Lambda) \hat{\phi}(x) \hat{U}^{\dagger}(\Lambda) = \hat{\phi}(\Lambda^{-1} x),$$
where $\Lambda$ is an arbitrary orthochronous Lorentz transformation (and analogously for space-time translations).
In order to have a Hamiltonian that is bounded from below, which we need to have a stable ground state, the negative-frequency modes have to enter as a term proportional to a creation operator and the positive-frequency modes as a term proportional to an annihilation operator (in non-relativistic QFT the field consists only of a superposition of annihilation operators!). In this way the negative-frequency solutions appear as positive-energy modes of either the same particles as represented by the annihilation operators associated with the positive-fequency modes (then for a scalar field you have an Hermitean scalar field) or a different kind of particles, which necessarily have the same mass as the particles but with the opposite charge of the conserved Noether current from the then possible U(1) symmetry (invariance under global phase rotations of the field). These are called the anti-particles associated with the particles.
This analysis goes through for particles with any spin $s \in \{0,1/2,1,3/2,\ldots \}$.
It also follows from the representation theory of the Poincare group that half-integer (integer) spin particles must be quantized as fermions (bosons), which is the famous spin-statistics theorem. Further, any local microcausal QFT with Hamiltonian bounded from below is also necessarily symmetric under the "grand reflection" CPT (charge conjugation, parity=spatial reflections, and time reversal), which is the famous Pauli-Lueders CPT theorem. There's no necessity for C, P, T, or CP to be conserved for such a QFT, and indeed the weak interaction violates all of these discrete symmetries, but of course not CPT.
6. Jan 17, 2017
### binbagsss
mmm I have noether's theorem roughly as: if S is invariant up to a surface term under some transformation this implies there is a conserved current.
The complex scalar field leave S invariance under a complex phase rotation. we find the conserved current.
We then operate with H and Q, H the hamiltionian and Q the conserved charge assoaiced to the conserved current described above, on both a+|0> and b+|0> , where, from the quantisation of the complex scalar field, a+ is the creation of particle type 1 and b+ is the creator of particle type 2, and the outcome is that operating with H returns the same energy(mass), whilst operating with Q returns the same charge but with a different sign, thus showing the existence of particles and antiparticles.
7. Jan 17, 2017
### stevendaryl
Staff Emeritus
Yes, what you're saying is right. I was saying that even at the level of a classical field theory, the current for a complex scalar field must involve charge densities of both signs.
Draft saved Draft deleted
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http://www.science.gov/topicpages/e/erbium+152.html | These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1
E-print Network
We work out a simple, pulsed pump-probe measurement scheme to measure the homogeneous linewidth of an atomic transition in an inhomogeneously broadened spectral line in a solid state environment. We apply the theory to the I_11/2 -- I_15/2 optical transition of erbium in LiNbO_3:Er^3+ crystal. Beside obtaining the homogeneous linewidth, we have estimated the population relaxation time as well.
Mandula, G; Sinkovicz, P; Kovács, L; 10.1088/1757-899X/15/1/012062
2010-01-01
2
E-print Network
Microspherical Laser In Erbium-Ytterbium-Doped Glass G. Nunzi Conti (1), C. Arnaud (2), M. Boustimi/2 4 I15/2 transition at 1550 nm of erbium ions in phosphate glass spheres. We also report on the laser emission. Keywords: Whispering Gallery Mode, Erbium, Microlaser, Optical Feedback 1. Introduction
3
A study of the complex atomic susceptibility of erbium-doped fiber amplifiers operating near the 1.53-?m transition (4I 13\\/2-4I15\\/2) developed from a semiclassical theoretical description is presented. Expressions for the emission cross section ?e(?) and absorption cross section ?a(?) of erbium:glass as a quasi-three-level laser system with Stark-split sublevel manifolds are derived. The results are used to calculate the cross sections
Emmanuel Desurvire
1990-01-01
4
E-print Network
in Erbium doped fluoride glasses Patrice F´eron GIS "FOTON" Laboratoire d'Optronique (CNRS-UMR 6082) ENSSAT on the optical transition 4 I13/2 -4 I15/2 around 1.55µm of Erbium doped fluoride glass, which offers potential
5
Nanocolloids of compounds containing fluorescent rare earth ions have recently attracted significant attention as agents for biolabeling, bioimaging, bio- and chemical sensing, and other applications. Erbium oxide nanocolloids have been prepared for the first time in water and gammabutyrolactone. Optical dynamic scatterometry and atomic force microscopy determined an average size (average mean height) of erbium oxide nanoparticles to be 10-11 nm. Prominent optical absorption peaks of the nanocolloids at 442.5 nm, 450.0 nm, 487.2 nm (strong), 492.0 nm, 523.0 nm (strong), 541.6 nm, 548.6 nm, 652.6 nm, and 665.7 nm (strong) can be attributed to erbium ions hosted within nanoparticles. Laser fluorescence spectroscopy of the nanocolloids was conducted using excitations with the lines of argon-ion laser (514 nm, 488 nm, 476 nm, and 458 nm) and 980-nm semiconductor laser. Strong green emission at 571 nm is more likely from transition between 4S3/2 and 4I15/2 levels and relatively weak red emissions from transition between 4I9/2 and 4I15/2 level of erbium was observed at excitation with visible laser radiation 488 nm and 476 nm. The reported nanocolloids thus showed to be good candidates for fluorescent biosensing applications and also as a new lasing filling medium in fiber lasers.
Patel, Darayas; Vance, Calvin; King, Newton; Jessup, Malcolm; Sarkisov, Sergey
2009-02-01
6
E-print Network
Role of CaO addition in the local order around Erbium in SiO2ÂGeO2ÂP2O5 fiber preforms F. d/crystalline local structure around the Er3+ ion is evidenced. Keywords: Optic fibers; EXAFS; Erbium; Nanoparticles 1. Among the rare earths, erbium is especially interesting because the 4I13/2 - 4I15/2 transition at 1
Boyer, Edmond
7
SciTech Connect
Erbium diffusion in silicon dioxide layers prepared by magnetron sputtering, chemical vapor deposition, and thermal growth has been investigated by secondary ion mass spectrometry, and diffusion coefficients have been extracted from simulations based on Fick's second law of diffusion. Erbium diffusion in magnetron sputtered silicon dioxide from buried erbium distributions has in particular been studied, and in this case a simple Arrhenius law can describe the diffusivity with an activation energy of 5.3{+-}0.1 eV. Within a factor of two, the erbium diffusion coefficients at a given temperature are identical for all investigated matrices.
Lu Yingwei; Julsgaard, B.; Petersen, M. Christian [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Jensen, R. V. Skougaard [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Pedersen, T. Garm; Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark); Larsen, A. Nylandsted [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark)
2010-10-04
8
SciTech Connect
The erbium silicate formation processes during annealing in Ar gas were monitored by synchrotron radiation grazing incidence X-ray diffraction (GIXD) in real time and the optical properties of the silicates were investigated by photoluminescence measurements in spectral and time-resolved domains. The GIXD measurements show that erbium silicates and erbium oxide are formed by interface reactions between silicon oxide and erbium oxides deposited on silicon oxide by reactive sputtering in Ar gas and O{sub 2}/Ar mixture gas ambiences. The erbium silicates are formed above 1060 degree sign C in Ar gas ambience and above 1010 degree sign C in O{sub 2}/Ar gas ambience, and erbium silicides are dominantly formed above 1250 degree sign C. The I{sub 15/2}-I{sub 13/2} Er{sup 3+} photoluminescence from the erbium oxide and erbium silicate exhibits abnormal temperature dependence, which can be explained by the phonon-assisted resonant absorption of the 532-nm excitation photons into the {sup 2}H{sub 11/2} levels of Er{sup 3+} ions of the erbium compounds.
Omi, H.; Tawara, T.; Tateishi, M. [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato- Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)
2012-03-15
9
SciTech Connect
An erbium-doped microlaser is demonstrated utilizing SiO{sub 2} microdisk resonators on a silicon chip. Passive microdisk resonators exhibit whispering-gallery-type modes (WGM's) with intrinsic optical quality factors of up to 6x10{sup 7} and were doped with trivalent erbium ions (peak concentration {approx}3.8x10{sup 20} cm{sup -3}) using MeV ion implantation. Coupling to the fundamental WGM of the microdisk resonator was achieved by using a tapered optical fiber. Upon pumping of the {sup 4}I{sub 15/2}{yields}{sup 4}I{sub 13/2} erbium transition at 1450 nm, a gradual transition from spontaneous to stimulated emission was observed in the 1550-nm band. Analysis of the pump-output power relation yielded a pump threshold of 43 {mu}W and allowed measuring the spontaneous emission coupling factor: {beta}{approx_equal}1x10{sup -3}.
Kippenberg, T. J.; Kalkman, J.; Polman, A.; Vahala, K. J. [Department of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States); Center for Nanophotonics, FOM-Institute AMOLF, Amsterdam (Netherlands); Department of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)
2006-11-15
10
SciTech Connect
Infrared optical emission from erbium-doped silica nanowires is shown to have property characteristic of the material nanostructure and to provide the basis for the fabrication of integrated photonic devices and biosensors. Silica nanowires of approximately 150 nm diameter were grown on a silicon wafer by metal-induced growth using a thin (20 nm) sputter-deposited palladium layer as a catalyst. The resulting wires were then ion implanted with 110 keV ErO{sup -} ions and annealed at 900 deg. C to optically activate the erbium. These wires exhibited photoluminescence emission at 1.54 {mu}m, characteristic of the {sup 4}I{sub 15/2}-{sup 4}I{sub 13/2} transition in erbium; however, comparison to similarly implanted fused silica layers revealed stronger thermal quenching and longer luminescence lifetimes in the nanowire samples. The former is attributed to an increase in defect-induced quenching partly due to the large surface-volume ratio of the nanowires, while the latter is attributed to a reduction in the optical density of states associated with the nanostructure morphology. Details of this behavior are discussed together with the implications for potential device applications.
Elliman, R. G.; Wilkinson, A. R.; Kim, T.-H. [Department of Electronic Materials Engineering, Australian National University, Canberra ACT0200 (Australia); Sekhar, P. K.; Bhansali, S. [Nanomaterials and Nanomanufacturing Research Center, Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Ave., Tampa, Florida 33620 (United States)
2008-05-15
11
E-print Network
Low threshold erbiumLow threshold erbium--implantedimplanted toroidal microcavity laserstoroidal  Ultra-high-Q toroidal microcavities  Erbium-implanted microcavity lasers Analysis  Coupled harmonicFransisco Motivations : Erbium-doped microcavity lasers Neodymium-doped microsphere lasers  Pth = 200 nW  V
12
We reports light emission from Erbium Oxide nanoparticles. The nanoparticles, with 45 nm diameter, were obtained in the form of nanopowder. These nanoparticles were characterized for light emission under a 30 mW, 532 nm Nd:YAG laser excitation and a Photoluminescence (PL) system, made by Princeton Instrumentation, with a Pixis brand CCD camera. The nanoparticles were stick on a scotch tape and placed in the PL system. Spectrum of the light emitted from the nanoparticles was obtained and analyzed after subtracting the background spectrum. Two emission peaks were observed around 554 nm and 820 nm. The green emission at 554 nm was obtained as a result of ^2H11/2 ->^4I15/2 transition, and the near infrared emission from ^4I9/2->^4I15/2 transition. The process was also repeated in vacuum and it was found that the green emission enhances tremendously, showing the importance of Erbium Oxide nanoparticles optical and biophotonics applications.
2011-10-01
13
Erbium-doped fiber amplifiers are modeled using the propagation and rate equations of a homogeneous two-level laser medium. Numerical methods are used to analyze the effects of optical modes and erbium confinement on amplifier performance, and to calculate both the gain and amplified spontaneous emission (ASE) spectra. Fibers with confined erbium doping are completely characterized from easily measured parameters: the ratio
C. Randy Giles; Emmanuel Desurvire
1991-01-01
14
E-print Network
Plasmon-enhanced erbium luminescence H. Mertensa and A. Polman Center for Nanophotonics, FOM that the photoluminescence intensity of optically active erbium ions positioned in close proximity of anisotropic Ag with the erbium emission. In addition, the photoluminescence intensity enhancement is found to be polarized
Polman, Albert
15
E-print Network
1744 OPTICS LETTERS / Vol. 21, No. 21 / November 1, 1996 Dual-stage erbium-doped, erbium Received June 3, 1996 By concatenating an aluminum-codoped erbium-doped fiber with an efficient erbium energy transfer between erbium and ytterbium ions, we are able to pump the second stage with a high
Park, Namkyoo
16
SciTech Connect
The transmittance spectra of erbium phthalocyanine complexes in the mid- and near-infrared wavelength regions are studied. A detailed identification of the transmittance lines is presented for three types of phthalocyanine complexes. Data on the absorption of electromagnetic radiation at the wavelengths around 1.5 {mu}m due to the {sup 4}I{sub 13/2} {sup {yields}} {sup 4}I{sub 15/2} intracenter transitions between the levels of the erbium ions incorporated into the samples are obtained. It is found that some of the mid-infrared absorption lines shift when the number of organic ligands is increased by a factor of 2 or 3. It is shown that the absorption coefficient at the wavelengths around 1.5 {mu}m is equal to 27.5, 32.5, and 74 cm{sup -1} for erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine, respectively.
Belogorokhov, I. A., E-mail: [email protected]; Tikhonov, E. V.; Breusova, M. O.; Pushkarev, V. E.; Tomilova, L. G.; Khokhlov, D. R. [Moscow State University (Russian Federation)
2007-10-15
17
ERIC Educational Resources Information Center
A course guide for students in English 152 of Oakland Community College, a composition course in argumentative writing, this document gives the class schedule, the course outline, examples of writing, worksheets, ways of preparing bibliography and note cards, checklists, and a research bibliography, as well as presenting other cogent materials.…
Hudson, James
18
We propose and demonstrate a novel hybrid Brillouin\\/erbium fiber laser that uses both Brillouin gain in single-mode optical fiber and gain in erbium-doped fiber. The lasing frequency was accurately determined by the Brillouin shift in single-mode optical fiber and was 10.35GHz from the Brillouin pump. Large powers could be extracted because of incorporation of erbium-doped fiber in the laser resonator.
Gregory J. Cowle; Dmitrii Yu. Stepanov
1996-01-01
19
Spectral gain hole-burning at ?0=1.53 ?m was observed in an erbium-doped fiber amplifier at temperatures between 4.2 and 77 K. The hole width was found to broaden with temperature for T ⩾20 K according to a T1.73 law. From the data, the room-temperature homogeneous linewidth associated with the 1.531-?m transition in the 4I13\\/2-4I15\\/2 laser system was determined to be ??h=11.5
E. Desurvire; J. L. Zyskind; J. R. Simpson
1990-01-01
20
Room temperature photoluminescence of Er ions at 1.54 ?m corresponding to 4I13\\/2?4I15\\/2 transition in the ion f-shell was observed in erbium-doped hydrogenated amorphous silicon carbide films (a-Si1?xCx:H?Er?). Films of a-Si1?xCx:H?Er? were prepared by co-sputtering of graphite and Er targets applying the magnetron-assisted silane-decomposition technique with mixtures of Ar and silane. The composition of films (x) was 0?x?0.29. The concentration of
E. I Terukov; V. Kh Kudoyarova; A. N Kuznetsov; W Fuhs; G Weiser; H Kuehne
1998-01-01
21
SciTech Connect
Erbium oxide (Er{sub 2}O{sub 3}) is a rare earth oxide of interest because of its chemical and thermal stability and high melting point, 2,430 C. However, there is relatively little information available regarding the relation between the structure and the mechanical properties of this material. A densification study of polycrystalline erbium oxide powders is reported here. Erbium oxide pellets were uniaxially pressed (40--280 MPa) and sintered (1,500--1,800 C) in order to obtain density data for as-received commercial powders. In addition, the particle size and distribution of as-received powders were varied by milling and the effects on densification were studied. The powders were characterized for particle size, phase and impurity content and surface area. The mechanical properties of high density sintered erbium oxide bodies were characterized using indentation hardness and toughness as a function of temperature and microstructure. Relations between the microstructure and mechanical properties are described.
Neuman, A.; Platero, M.; Romero, R.; McClellan, K.J.; Petrovic, J.J.
1997-03-01
22
Recent results obtained for Er2O3-SiO2 monolithic xerogels and erbium activated SiO2-TiO2 planar waveguides are presented. Monolithic erbium-activated silica xerogels with erbium content ranging from 0 up to 40000 ppm were prepared by the sol-gel technique. Samples were densified by thermal treatment in air at 950 degrees C for 120 hours. The densification degree and the relative content of hydroxyl groups were studied by NIR absorption and Raman spectroscopies. Emission at 1.5 micrometers , characteristic of the 4I13/2 yields 4I15/2 transition of Er3+ ions, was observed at room temperature for all monolithic samples upon continuous wave excitation at 980 nm. For the 5000 Er/Si ppm doped xerogel, an intense photoluminescence was observed with a lifetime of 8 ms for the metastable 4I13/2 level. Passive and erbium-activated SiO2-TiO2 planar waveguides, monomode at 632.8 nm, were prepared by a dip-coating technique. Some parameters such as H2O content, intermediate and final thermal treatments, and the molar ratio TiO2/SiO2 were modified during the preparation of the solution in order to minimize the final content of residual hydroxyl groups and the phase separation between silica and titania. Raman spectroscopy was used to check the structural properties of the waveguides. A lifetime of 7 ms was measured for the metastable 4I13/2 level in a 93SiO2-7TiO2 planar waveguide activated by 10000 ppm Er/(Si + Ti). The best value of the attenuation coefficient was of 0.5 dB/cm at 632.8 nm.
Zampedri, Luca; Tosello, Cristiana; Rossi, Flavio; Ronchin, Sabina; Rolli, Raffaella; Montagna, Maurizio; Chiasera, Alessandro; Righini, Giancarlo C.; Pelli, Stefano; Monteil, Andre; Chaussedent, Stephane; Bernard, Christope; Duverger, Claire; Ferrari, Maurizio; Armellini, Cristina
2001-04-01
23
E-print Network
Absorption bleaching by stimulated emission in erbium-doped silicon-rich silicon nitride waveguides 133641); published December 16, 2010 Stimulated emission from sensitized erbium ions in silicon in the photoinduced absorption of the probe at the wavelength of erbium emission is observed and is attributed
Lipson, Michal
24
E-print Network
1 Erbium emission properties in nanostructured fibers Wilfried Blanc,1 Bernard Dussardier,1 the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in fiber preforms. Here we present the achieved stabilization of nanometric erbium-doped dielectric nanoparticles within the core of silica fibers
25
E-print Network
Enhanced Light Emission from Erbium Doped Silicon Nitride in Plasmonic Metal and nano-particle arrays in a metal- insulator-metal structures are fabricated on an erbium doped silicon, J. Warga, S. N. Basu, "Sensitized Erbium emission from silicon-rich nitride/silicon super- lattice
Vuckovic, Jelena
26
E-print Network
Controlled spontaneous emission in erbium-doped microphotonic materials #12;Controlled spontaneous emission in erbium-doped microphotonic materials Jeroen Kalkman ISBN 90-393-0295-2 A digital version of this thesis can be downloaded from http://www.amolf.nl #12;Controlled spontaneous emission in erbium
Polman, Albert
27
E-print Network
UNCORRECTED PROOF 2 Luminescence of erbium-doped bismuthÂborate glasses 3 Isabella-Ioana Oprea Received 26 May 2005; accepted 12 July 2005 7 Abstract 8 Absorption and luminescence properties of erbium for the composition range 25Â65 mol% Bi2O3. A JuddÂOfelt analysis of the typical erbium bands in the absorption
Osnabrück, Universität
28
E-print Network
Characterization of new erbium-doped tellurite glasses and fibers S. Marjanovic a,*, J. Toulouse of their excellent optical and chemical properties. The emission spectrum from erbium in tellurite glasses is almost on the microscopic structure of these glasses, and a study of the erbium emission in fibers fabricated from
Dierolf, Volkmar
29
E-print Network
Erbium-doped Lithium Niobate waveguide lasers: recent progress W. Sohler, D. Dey, B. Das, S. Reza, Warburger Str. 100, 33098 Paderborn, Germany ABSTRACT Erbium diffusion doping of LiNbO3 (e.g. 30 nm / 1130 achieved with an output power up to 150 µW. Keywords: Erbium, Lithium Niobate, integrated optics, waveguide
Mohseni, Hooman
30
PubMed
In this paper, we theoretically investigate all-optical logical gates based on the pump-induced resonant nonlinearity in an erbium-doped fiber coupler. The resonant nonlinearity yielded by the optical transitions between the I15/24 states and I13/24 states in Er3+ induces the refractive index to change, which leads to switching between two output ports. First, we do a study on the switching performance, and calculate the extinction ratio (Xratio) of the device. Second, using the Xratio, we obtain the truth tables of the device. The results reveal that compared with other undoped nonlinear couplers, the erbium-doped fiber coupler can drop the switching threshold power. We also obtain different logic gates and logic operations in the cases of the same phase and different phase of two initial signals by changing the pump power. PMID:25607960
Li, Qiliang; Zhang, Zhen; Li, Dongqiang; Zhu, Mengyun; Tang, Xianghong; Li, Shuqin
2014-12-01
31
SciTech Connect
As a heavy rare earth oxide, erbium oxide (Er{sub 2}O{sub 3}) has many attractive properties. Monoclinic Er{sub 2}O{sub 3} has useful properties not found in stable cubic Er{sub 2}O{sub 3}, such as unique optical properties and high radiation damage tolerance. In this study, cubic Er{sub 2}O{sub 3} coating and Er{sub 2}O{sub 3} coating with mixed phases were prepared. The Raman scattering spectra of these coatings were investigated by using a confocal micro-Raman spectrometer equipped with 325, 473, 514, 532, 633, and 784?nm lasers. A total of 17 first-order Raman modes of monoclinic Er{sub 2}O{sub 3} were identified and assigned. The modes at 83, 112, 152, 170, 278, 290, 409, 446, 478, 521, 603, and 622?cm{sup ?1} are of A{sub g} symmetry, whereas modes at 71, 98, 333, 409, 446, and 468?cm{sup ?1} are of B{sub g} symmetry. This research provides basic data necessary for the characterization of monoclinic Er{sub 2}O{sub 3} by Raman spectroscopy.
Yan, D.; Wu, P., E-mail: [email protected]; Zhang, S. P.; Liang, L.; Yang, F.; Pei, Y. L.; Chen, S. [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China)
2013-11-21
32
SciTech Connect
We have studied the active properties of erbium-doped aluminophosphosilicate (APS) core fibres in wide ranges of erbia, alumina and phosphorus pentoxide concentrations. The absorption and luminescence spectra of the P{sub 2}O{sub 5}- or Al{sub 2}O{sub 3}-enriched erbium-doped APS fibres are shown to be similar to those of the erbium-doped fibres singly doped with phosphorus pentoxide or alumina, respectively. The formation of AlPO{sub 4} in APS fibres leads not only to a reduction in the refractive index of the glass but also to a marked increase in Er{sub 2}O{sub 3} solubility in silica. (optical fibres)
Likhachev, M E; Bubnov, M M; Zotov, K V; Medvedkov, O I [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Lipatov, D S; Yashkov, M V; Gur'yanov, Aleksei N [Institute of Chemistry of High-Purity Substances, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)
2010-09-10
33
The paper reports upconversion luminescence behaviour and infra-red spectroscopic pattern of erbium doped yttrium (III) oxide phosphor. Sample was synthesized by solid state reaction method with variable concentration or erbium (0.5-2.5 mol%). The conventional solid state method is suitable for large scale production and eco-friendly method. The prepared sample was characterized by X-ray diffraction (XRD) technique. From structural analysis by XRD technique shows cubic structure of prepared sample with variable concentration of erbium and no impurity phase were found when increase the concentration of Er3+. Particle size was calculated by Scherer's formula and it varies from 67 nm to 120 nm. The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM) technique. The surface morphology of the sample shows good connectivity with grains as well as some agglomerates formation occurs in sample. The functional group analysis was done by Fourier transform infra-red technique (FTIR) analysis which confirm the formation of Y2O3:Er3+ phosphor was prepared. The results indicated that the Y2O3:Er3+ phosphors might have high upconversion efficiency because of their low vibrational energy. Under 980 nm laser excitation sample shows intense green emission at 555 nm and orange emission at 590 nm wavelength. For green emission transition occurs 2H11/2 ? 4I15/2, 4S3/2 ? 4I15/2 for upconversion emissions. Excited state absorption and energy transfer process were discussed as possible upconversion mechanisms. The near infrared luminescence spectra was recorded. The upconversion luminescence intensity increase with increasing the concentration or erbium up to 2 mol% after that luminescence intensity decreases due to concentration quenching occurs. Spectrophotometric determinations of peaks are evaluated by Commission Internationale de I'Eclairage (CIE) technique. From CIE technique the dominant peak of from PL spectra shows intense green emission so the prepared phosphor is may be useful for green light emitting diode (GLED) application.
Dubey, Vikas; Tiwari, Ratnesh; Tamrakar, Raunak Kumar; Rathore, Gajendra Singh; Sharma, Chitrakant; Tiwari, Neha
2014-11-01
34
E-print Network
Ultracold atoms confined in a dipole trap are submitted to a potential whose depth is proportional to the real part of their dynamic dipole polarizability. The atoms also experience photon scattering whose rate is proportional to the imaginary part of their dynamic dipole polarizability. In this article we calculate the complex dynamic dipole polarizability of ground-state erbium, a rare-earth atom that was recently Bose-condensed. The polarizability is calculated with the sum-over-state formula inherent to second-order perturbation theory. The summation is performed on transition energies and transition dipole moments from ground-state erbium, which are computed using the Racah-Slater least-square fitting procedure provided by the Cowan codes. This allows us to predict 9 unobserved odd-parity energy levels of total angular momentum J=5, 6 and 7, in the range 25000-31000 cm-1 above the ground state. Regarding the trapping potential, we find that ground-state erbium essentially behaves like a spherically-symmetric atom, in spite of its large electronic angular momentum. We also find a mostly isotropic van der Waals interaction between two ground-state erbium atoms, characterized by a coefficient C_6^{iso}=1760 a.u.. On the contrary, the photon-scattering rate shows a pronounced anisotropy, since it strongly depends on the polarization of the trapping light.
Maxence Lepers; Jean-François Wyart; Olivier Dulieu; --
2013-10-23
35
SciTech Connect
Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report show that hydride film processing parameters directly impact thermal stability. Issues to be addressed include desorption kinetics for dihydrides and trihydrides, and the effect of film growth parameters, loading parameters, and substrate selection on desorption kinetics.
Ferrizz, Robert Matthew
2007-08-01
36
An integrated standing-wave, single frequency, erbium fiber laser having a laser linewidth of less than 47 kHz is reported. The monolithic fiber laser incorporated two highly reflective intracore Bragg reflectors which provide both cavity feedback and adequate longitudinal mode discrimination. The narrow linewidth single-mode operation and monolithic construction may make this a valuable communications\\/sensor source.
G. A. Ball; W. W. Morey; W. H. Glenn
1991-01-01
37
E-print Network
A spectrophotometric study of erbium (III) speciation in chloride solutions at elevated 2006; accepted 1 April 2006 Abstract The speciation of erbium in chloride-bearing solutions. Keywords: Rare Earth Elements; Erbium; Chloride; Aqueous solution; Speciation; Formation constants
Long, Bernard
38
Erbium activated SiO2-HfO2 planar waveguides, doped with Er3+ concentrations ranging from 0.01 to 4 mol%, were prepared by sol-gel method. The films were deposited on v-SiO2 and silica-on-silicon substrates using dip-coating technique. The waveguides show high densification degree, effective intermingling of the two film components, and uniform surface morphology. The waveguide deposited on silica-on-silicon substrates shows one single propagation mode at 1.5?m, with a confinement coefficient of 0.81 and an attenuation coefficient of 0.8 dB/cm at 632.8nm. Emission in the C-telecommunication band was observed at room temperature for all the samples upon continuous-wave excitation at 980 nm or 514.5 nm. The shape of the emission band corresponding to the 4I13/2-->4I15/2 transition is found to be almost independent both on erbium content and excitation wavelength, with a FWHM between 44 and 48 nm. The 4I13/2 level decay curves presented a single-exponential profile, with a lifetime ranging between 1.1-6.6 ms, depending on the erbium concentration. Infrared to visible upconversion luminescence upon continuous-wave excitation at 980 nm was observed for all the samples. Channel waveguide in rib configuration was obtained by etching the active film in order to have a well confined mode at 1.5 ?m.
Goncalves, Rogeria R.; Carturan, Giovanni; Zampedri, Luca; Ferrari, Maurizio; Armellini, Cristina; Chiasera, Alessandro; Mattarelli, M.; Moser, Enrico; Montagna, Maurizio; Righini, Giancarlo C.; Pelli, Stefano; Nunzi Conti, Gualtiero; Ribeiro, Sidney J. L.; Messaddeq, Younes; Minotti, Antonio; Foglietti, Vittorio; Portales, Herve
2003-06-01
39
E-print Network
281 M�TAMAGN�TI SME DU GRENAT D'ERBIUM ET DE GALLIUM J. P. REDOULES, P. CARRARA, A. R. FERT, M. C gallate d'erbium suivant les trois directions [001], [011] et [111], à une température voisine de 0,080 °K modèle d'Ising. Abstract. 2014 Experimental study of the metamagnetism of erbium gallium garnet along
40
Brillouin\\/erbium fiber lasers, which have recently been demonstrated, operate with a combination of Brillouin gain and gain in erbium-doped fiber. In this letter, we describe techniques for cascading the Brillouin\\/erbium fiber laser to generate optical combs, and experimentally demonstrate optical comb generation. Internal and external cascading techniques are demonstrated. The line spacing in the combs is approximately 10 GHz, with
Gregory J. Cowle; D. Yu. Stepanov
1996-01-01
41
E-print Network
The enhancement of Er$^{3+}$-based up-conversion for photovoltaics in multilayer porous silicon photonic structures is considered theoretically and experimentally. Transfer matrix simulations are used to assess the increased photonic density of states that results from the slowing of energy propagation at the short-wavelength edge of one-dimensional photonic band gaps. An indirect calculation of Er$^{3+}$ absorption enhancement within slow-light modes is then used to illustrate an increase in absorption over the bulk value: the effective absorption coefficient is shown to increase by more than 22% over a broad spectral region and by more than 400% over a narrow region. Erbium-doped porous silicon photonic crystals are fabricated with the photonic band edge coincident with the $^{4}I_{15/2} \\rightarrow^{4}I_{13/2}$ Er$^{3+}$ transition. Challenges in fabrication and the results of compositional analysis are discussed. An angular-dependent photoluminescence measurement demonstrates emission intensity that varie...
Johnson, Craig M; Tan, H Hoe; Conibeer, Gavin J
2012-01-01
42
Code of Federal Regulations, 2010 CFR
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2010-01-01
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Code of Federal Regulations, 2011 CFR
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2011-01-01
44
Code of Federal Regulations, 2010 CFR
...2010-04-01 2010-04-01 false Computed value. 152.106 Section 152.106 Customs Duties...Valuation of Merchandise § 152.106 Computed value. (a) Elements. The computed value of imported merchandise is the sum of:...
2010-04-01
45
Erbium doped waveguides are very promising candidates for the realization of a quantum memory based on reversible absorption in a controllably broadened absorption line (CRIB). First of all the wavelength of the storage transition'' matches well with the telecom wavelength'' most often used for long-distance quantum communications in the past. Secondly the interaction length between light and ions can be made very long within a waveguide. Thus high optical depth can be achieved as required for the proposal. We have measured the homogeneous linewidth of the I15/2->I13/2 transition in a Erbium-doped SiO2 glass fiber and a LiNOb3 Crystal with a waveguiding structure at a wavelength of ?=1530 nm. The homogeneous lifetime in the glass shows an abnormal magnetic field dependency and is in the order of several ?s, which is an improvement of two orders of magnitude compared to existing data in similar material. Also we investigated the preservation of information encoded into the relative phase and amplitudes of optical pulses during storage and retrieval in an optical memory based on stimulated photon echo.
Staudt, M. U.; Hastings-Simon, S. R.; Lauritzen, B.; Afzelius, M.; de Riedmatten, H.; Sangouard, N.; Simon, C.; Tittel, W.; Gisin, N.
2007-03-01
46
E-print Network
Ultracold atoms confined in a dipole trap are submitted to a potential whose depth is proportional to the real part of their dynamic dipole polarizability. The atoms also experience photon scattering whose rate is proportional to the imaginary part of their dynamic dipole polarizability. In this article we calculate the complex dynamic dipole polarizability of ground-state erbium, a rare-earth atom that was recently Bose-condensed. The polarizability is calculated with the sum-over-state formula inherent to second-order perturbation theory. The summation is performed on transition energies and transition dipole moments from ground-state erbium, which are computed using the Racah-Slater least-square fitting procedure provided by the Cowan codes. This allows us to predict 9 unobserved odd-parity energy levels of total angular momentum J=5, 6 and 7, in the range 25000-31000 cm-1 above the ground state. Regarding the trapping potential, we find that ground-state erbium essentially behaves like a spherically-symme...
Lepers, Maxence; Dulieu, Olivier; --,
2013-01-01
47
SciTech Connect
Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.
Zavadil, Kevin Robert; Snow, Clark Sheldon; Brumbach, Michael Todd
2010-09-01
48
We evaluated the effects of the erbium:YAG laser (2.9 µm wavelength) on ocular structures. Energy was successfully transmitted through a fiberoptic bundle for intraocular and extraocular applications. The wavelength was strongly absorbed by ocular tissues, producing ablations with minimal thermal damage. Our results indicated that the erbium: YAG laser may have potential uses as a photoablative tool to reshape the
Gholam A. Peyman; Naoko Katoh
1987-01-01
49
In this paper, a simple rate equation model is used to make the first prediction of the noise figure for erbium-doped fiber amplifiers for both co- and counterpropagating pumps. It is shown that erbium amplifiers can be operated with noise figures very close to the 3 dB quantum limit. If the application requires both low noise and maximum gain, the
R. Olshansky
1988-01-01
50
SciTech Connect
Improving the up-conversion efficiency is the key issue in tellurite glasses. The quantum efficiency, radiative transition rate and lifetimes of excited states are greatly influenced by the optical properties of the host material, ligand field, multiphonon relaxation processes, impurities, temperature and concentration of erbium ions. We develop a comprehensive 4-level model to examine the radiative and nonradiative (NR) decay processes for the green ({sup 4}S{sub 3/2}{yields}{sup 4}I{sub 15/2}) and red ({sup 4}F{sub 9/2}{yields}{sup 4}I{sub 15/2}) emission over a temperature range of (10-340 K) and concentration range of (0.1-4.5 mol.%). Concentration dependent enhancement and thermal quenching of efficiency for up-conversion is investigated using the derived rate equations. These features are attributed to the NR energy transfer processes, trapped impurity effects, and thermal assisted hopping. The unusual nature of temperature and concentration dependent quenching effects for green and red emission is queries for further investigations. It is further suggested that to achieve higher infrared to visible up-converted efficiency in tellurite glasses the NR channels for energy and charge transfer by phonon and impurity mediated process has to be minimized. Our results on pump power dependent emission intensity, quantum efficiency, luminescence intensity, radiative lifetimes, and transition probabilities are in conformity with other experimental findings.
Ghoshal, S. K.; Sahar, M. R.; Rohani, M. S. [Advanced Optical Materials Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Tewari, H. S. [Department of Pure and Applied Physics, Guru Ghasidas University Bilaspur - 495009 (CG) (India)
2011-11-22
51
E-print Network
We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic field. By means of evaporative cooling in an optical dipole trap, we produce pure condensates of $^{168}$Er, containing up to $7 \\times 10^{4}$ atoms. Feshbach spectroscopy reveals an extraordinary rich loss spectrum with six loss resonances already in a narrow magnetic-field range up to 3 G. Finally, we demonstrate the application of a low-field Feshbach resonance to produce a tunable dipolar Bose-Einstein condensate and we observe its characteristic d-wave collapse.
Aikawa, K; Mark, M; Baier, S; Rietzler, A; Grimm, R; Ferlaino, F
2012-01-01
52
The molecular and ionic composition of vapor over erbium tribromide sublimed from the Knudsen effusion cell and the open surface of a single crystal was studied by high-temperature mass spectrometry. The partial pressures of ErBr3 and Er2Br6 molecules in saturated vapor and the ratio between their sublimation coefficients under free vaporization conditions were determined. The enthalpies and activation energies of sublimation of ErBr3 crystals in the form of monomers and dimers were calculated. The emission of and Er2 was recorded in studies of ionic sublimation in both modes. The enthalpies of formation of gas molecules and ions were determined.
Butman, M. F.; Kudin, L. S.; Motalov, V. B.; Kryuchkov, A. S.; Grishin, A. E.; Krämer, K. W.
2009-01-01
53
E-print Network
35 ROB. THAL�N. 2014 Spektralundersökningar rörande skandium, ytterbium, erbium och thulium (Recherches spectrales sur le scandium, l'ytterbium, l'erbium et le thulium ) ; Ofversigt af Kongl. Vetenskaps solutions de nitrates, l'une rose, riche en erbium, l'autre presclue incolore et riche en thulium. Plusieurs
54
SciTech Connect
Aged erbium tritide foil specimens are found to contain five distinctly different microstructural features. The general structure was of large columnar grains of ErT2. But on a fine scale, precipitates believed to be erbium oxy-tritides and helium bubbles could be identified. The precipitate size was in the range of ~10 nm and the bubbles were of an unusual planar shape on {111} planes with an invariant thickness of ~1 nm and a diameter on the order of 10 nm. Also, an outer layer containing no fine precipitate structure and only a few helium bubbles was present on foils. This layer is best described as a denuded zone which probably grew during aging in air. Finally, large embedded Er2O3 particles were found at low density and non-uniformly distributed, but sometimes extending through the thickness of the foil. A failure mechanism allowing the helium to escape is suggested by observed cracking between bubbles closer to end of life.
Gelles, David S.; Brewer, L. N.; Kotula, Paul G.; Cowgill, Donald F.; Busick, C. C.; Snow, C. S.
2008-01-01
55
Code of Federal Regulations, 2012 CFR
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...2014-01-01 2014-01-01 false Energy conservation practices. 152.609 Section 152...AIRPORTS AIRPORT AID PROGRAM Energy Conservation in Airport Aid Program § 152.609 Energy conservation practices. Each sponsor shall...
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Transient dynamic due to signal power fluctuations is the main impairment in reconfigurable transparent wavelength-division-multiplexing metro networks design. In this letter, we demonstrate an optical-gain-clamped erbium-doped waveguide amplifier using fiber Bragg grating filters. We show both theoretically and experimentally that it is virtually insensitive to signal transient and that it reduces overshoot by 10 dB compared to standard erbium-doped fiber
K. Ennser; G. Della Valle; M. Ibsen; J. Shmulovich; S. Taccheo
2005-01-01
68
PubMed
A cladding pumped multicore erbium-doped fiber amplifier for simultaneous amplification of 6 channels is demonstrated. Peak gain over 32 dB has been obtained at a wavelength of 1560 nm and the bandwidth measured at 20-dB gain was about 35 nm. Numerical modeling of cladding pumped multicore erbium-doped amplifier was also performed to study the properties of the amplifier. The results of experiment and simulation are found to be in good agreement. PMID:23037071
Abedin, K S; Taunay, T F; Fishteyn, M; DiGiovanni, D J; Supradeepa, V R; Fini, J M; Yan, M F; Zhu, B; Monberg, E M; Dimarcello, F V
2012-08-27
69
Detailed level schemes, decay schemes, and the experimental data on which they are based are presented for all nuclei with mass number A=152. The experimental data are evaluated; inconsistencies and discrepancies are noted; and adopted values for level and ?-ray energies, ? intensities, as well as for other nuclear properties are given. This evaluation replaces the A=152 evaluation published by Agda Artna-Cohen in Nuclear Data Sheets 79, 1 (1996) and the evaluation for 152Dy prepared by Balraj Singh and published in Nuclear Data Sheets 95, 995 (2002).
Martin, M. J.
2013-11-01
70
We experimentally quantify the contribution of magnetic dipole (MD) transitions to the near-infrared light emission from trivalent erbium-doped yttrium oxide (Er3+:Y2O3). Using energy-momentum spectroscopy, we demonstrate that the 4I13/2?4I15/2 emission near 1.5 ?m originates from nearly equal contributions of electric dipole (ED) and MD transitions that exhibit distinct emission spectra. We then show how these distinct spectra, together with the differing local density of optical states for ED and MD transitions, can be leveraged to control Er3+ emission in structured environments. We demonstrate that far-field emission spectra can be tuned to resemble almost pure emission from either ED or MD transitions and show that the observed spectral modifications can be accurately predicted from the measured ED and MD intrinsic emission rates.
Li, Dongfang; Jiang, Mingming; Cueff, Sébastien; Dodson, Christopher M.; Karaveli, Sinan; Zia, Rashid
2014-04-01
71
SciTech Connect
A series of erbium doped phosphate glass has been successfully fabricated, and the determination of their density and luminescence properties has been carried out. It is particularly interesting to study the effect of modifying oxides to the properties of the glass. The glass density reduces with the increasing content of Na{sub 2}O. The emission spectra from luminescence spectroscopy resolved six emission peaks from the excitation wavelength of 336.8 nm (3.69 eV). The emission of {sup 4}F{sub 7/2} gives two emission peaks, where the peak near 482 nm shows a higher intensity and the peak near 491 nm gives a weak emission spectra.
Rasid, A. A.; Rohani, M. S.; Sahar, M. R.; Kasim, A. [Advanced Optical Material Research Group, Physics Dept., Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)
2010-03-11
72
SciTech Connect
Optical characteristics of new generation of tellurite glasses having high stability against crystallization have been studied. As the initial reagents for the glasses synthesis on the base of tellurium oxide (TeO{sub 2}) there were used such oxides as WO{sub 3}, MoO{sub 3}, La{sub 2}O{sub 3}, Li{sub 2}CO{sub 3}, ZnO—Bi{sub 2}O{sub 2}CO{sub 3} and active components such as high purity Er{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, ErF{sub 3} and YbF{sub 3}. Intensities of luminescence at 1.53 µm of the erbium ions were determined after excitation at 975 nm. Experimental data obtained have shown the possibility to use the studied glasses doped by Er{sup 3+} and Yb{sup 3+} as active elements for fiber and integrated optics. - Graphical abstract: In contrast to the case of ZBLAN glass the TeO{sub 2}–WO{sub 3} (Er{sup 3+}) glass has bright intensity of luminescence at 1.53 µm for erbium ions that should be caused by excitation at 975 nm. Experimental data obtained have shown the possibility to use the studied glasses doped by Er{sup 3+} and Yb{sup 3+} as active elements for fiber and integrated optics. Display Omitted - Highlights: • We examined changes in growth of luminescence in doubly-doped tellurite glasses. • We found that luminescence grows in two orders by using Er{sup 3+} and Yb{sup 3+} at 1.53 ?m. • We see possibility to use those glasses as active elements for integrated optics.
Savikin, Alexander P.; Grishin, Igor A.; Sharkov, Valery V.; Budruev, Andrei V., E-mail: [email protected]
2013-11-15
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E-print Network
Single-Longitudinal-Mode Lanthanum-Codoped Bismuth-Based Erbium Doped Fiber Ring Laser K. K and demonstrate a stable single-longitudinal-mode lanthanum-codoped bismuth oxide- based erbium doped fiber ring
Wai, Ping-kong Alexander
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E-print Network
1 Design and fabrication of an intrinsicallygain flattened Erbium doped fiber amplifier B. Nagaraju fabrication of an intrinsically gain flattened Erbium doped fiber amplifier (EDFA) based on a highly
75
E-print Network
Erbium-doped transparent glass ceramic optical fibres: Characterization using mass spectroscopy properties of the erbium ions embedded within the phospho-silicate DNP. These results permit to get more
Boyer, Edmond
76
E-print Network
1 170 Gbit/s transmission in an erbium-doped waveguide amplifier on silicon Jonathan D. B. Bradley amplifying wavelength division multiplexed (WDM) signals. Alternatively, planar erbium-doped waveguide
Boyer, Edmond
77
...Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER ISSUANCE OF PATENTS IN FEE, CERTIFICATES OF COMPETENCY, REMOVAL OF RESTRICTIONS, AND SALE OF CERTAIN INDIAN LANDS § 152.1 Definitions. As used in this part:...
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Code of Federal Regulations, 2012 CFR
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Code of Federal Regulations, 2013 CFR
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40 Protection of Environment 18 2014-07-01...152 Protection of Environment ENVIRONMENTAL PROTECTION...STRATOSPHERIC OZONE Recycling and Emissions Reduction...refrigerant recovery or recycling equipment means...unsafe in its intended environment, and/or will...
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Code of Federal Regulations, 2011 CFR
40 Protection of Environment 17 2011-07-01...152 Protection of Environment ENVIRONMENTAL PROTECTION...STRATOSPHERIC OZONE Recycling and Emissions Reduction...refrigerant recovery or recycling equipment means...unsafe in its intended environment, and/or will...
2011-07-01
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2013-07-01
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Code of Federal Regulations, 2010 CFR
40 Protection of Environment 17 2010-07-01...152 Protection of Environment ENVIRONMENTAL PROTECTION...STRATOSPHERIC OZONE Recycling and Emissions Reduction...refrigerant recovery or recycling equipment means...unsafe in its intended environment, and/or will...
2010-07-01
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Code of Federal Regulations, 2010 CFR
...51.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...episode stage, including procedures for contact with public officials, major emission sources, public health, safety, and emergency agencies...
2010-07-01
87
E-print Network
Ultralow-threshold erbium-implanted toroidal microlaser on silicon A. Polmana) Department an erbium-doped microlaser on silicon operating at a wavelength of 1.5 m that operates at a launched pump threshold as low as 4.5 W. The 40 m diameter toroidal microresonator is made using a combination of erbium
Polman, Albert
88
E-print Network
Application of H Control on Pilot Tones in Erbium-Doped Fiber Amplifiers Y. Taing and L. Pavel the effects of cross gain modulation due to supervisory pilot tones within Erbium-Doped Fiber Amplifiers: (060.2410) Fibers, erbium; (060.2320) Fiber optics amplifiers and oscillators; (140.4480) Optical
Pavel, Lacra
89
E-print Network
Multiwavelength erbium-doped fiber laser employing a nonlinear optical loop mirror Xinhuan Feng a; accepted 6 July 2006 Abstract A stable and broad bandwidth multiwavelength erbium-doped fiber laser is about 0.1 dB within a 2-h period. Ã? 2006 Elsevier B.V. All rights reserved. Keywords: Erbium-doped fiber
Wai, Ping-kong Alexander
90
E-print Network
Periodic and non-periodic frequency selection in an erbium doped fiber laser by silica microdisk spectral filters. These filters can control the spectral emission of an erbium doped fiber laser erbium- doped fiber lasers anchored on the itu frequency grid," J. Lightwave Technol. 18, 825Â831 (2000
Peter, Yves-Alain
91
E-print Network
Energy backtransfer and infrared photoresponse in erbium-doped silicon pÂn diodes N. Hamelin,a) P, and infrared photocurrent, were performed on an erbium-implanted silicon pÂn junction in order to investigate surface. The PL intensity and PL lifetime measurements show weak temperature quenching of the erbium intra
Polman, Albert
92
E-print Network
Fast intracavity polarization dynamics of an erbium-doped fiber ring laser: Inclusion of stochastic The dynamics of a unidirectional erbium-doped fiber laser is investigated on a time scale short enough observations of the intracavity dynamics of an erbium-doped fiber laser. A polarization- controlling device
Yorke, James
93
E-print Network
Generation of a 660Â2100 nm laser frequency comb based on an erbium fiber laser Gabriel Ycas,1 present a multibranch laser frequency comb based upon a 250 MHz mode-locked erbium-doped fiber laser]. Here, we present a technique for generating a visible light frequency comb from a mode-locked erbium
94
E-print Network
Spectrum engineering of multiwavelength erbium doped fiber lasers with intensity-dependent [email protected] Abstract: We studied multiwavelength erbium-doped fiber lasers with intensity-dependent loss using rate. The realization of multiwavelength CW lasers with erbium-doped fiber at room temperature by incorporating
Wai, Ping-kong Alexander
95
E-print Network
Demonstration of an erbium-doped microdisk laser on a silicon chip T. J. Kippenberg* Department; published 16 November 2006 An erbium-doped microlaser is demonstrated utilizing SiO2 microdisk resonators optical quality factors of up to 6 107 and were doped with trivalent erbium ions peak concentration 3
Polman, Albert
96
E-print Network
Incorporation and optical activation of erbium in silicon using molecular beam epitaxy R. Serna; accepted for publication 23 October 1995 Erbium is incorporated in crystalline silicon during molecular of silicon with erbium has been a very active field of research since its introduction by Ennen et al.1
Polman, Albert
97
E-print Network
Physica B 300 (2001) 78Â90 Erbium as a probe of everything? A. Polman* FOM-Institute for Atomic; accepted 11 May 2001 Abstract Erbium is a lanthanide ion with unique electronic and optical properties, and photonic bandstructure. r 2001 Elsevier Science B.V. All rights reserved. Keywords: Erbium 1. Introduction
Polman, Albert
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E-print Network
Near-infrared thermal lens spectrometer based on an erbium-doped fiber amplifier and an acousto light from 1515 to 1590 nm was provided by an erbium-doped fiber amplifier EDFA . An acousto lens, acousto-optic tunable filter, erbium doped fiber amplifier, nucleotides. 1. Introduction Tran
Reid, Scott A.
99
E-print Network
Design and fabrication of an intrinsically gain flattened Erbium doped fiber amplifier B. Nagaraju1 of an intrinsically gain flattened Erbium- doped fiber amplifier (EDFA) based on a highly asymmetrical and concentric economics is a premium, because it would cut down the cost on gain flattening filter head. Keywords: Erbium
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E-print Network
H Optimal Control Design for Time Dependent Tones within Erbium-doped Fiber Amplifiers Yong Taing effects within Erbium-doped fiber amplifiers owed to pilot tone disturbances used for optical monitoring to this growth the application of Erbium-doped fiber amplifiers (EDFAs) within wavelength di- vision multiplexed
Pavel, Lacra
101
E-print Network
Two-wave mixing in an erbium-doped fiber amplifier for modulation depth enhancement of optically method based on two-wave mixing in an erbium- doped fiber amplifier for optical carrier reduction of optically carried microwave signals by using two-wave mixing and beam coupling phenomena in an erbium
102
E-print Network
Multiwavelength erbium-doped fiber ring laser source with a hybrid gain medium D.N. Wang a,*, F 17 December 2002; received in revised form 21 April 2003; accepted 30 September 2003 Abstract Erbium optical amplifier is incorporated into the cavity of an erbium-doped fiber ring laser to form a hybrid
Wai, Ping-kong Alexander
103
E-print Network
Erbium-doped nanoparticles in silica-based optical fibres Wilfried Blanc*, Valérie Mauroy, Bernard on the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in-situ in fiber preforms. By adding of nanometric erbium-doped dielectric nanoparticles within the core of silica fibers. We present
Boyer, Edmond
104
E-print Network
KonradÂZuseÂZentrum für Informationstechnik Berlin Dynamics of Erbium--doped Waveguide LasersÂ19 (August 1995) #12; Dynamics of Erbium--doped Waveguide Lasers: Modelling, Reliable Simulation : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 25 6 Conclusions 29 3 #12; 1 Introduction In parallel with the successful development of erbium
Zumbusch, Gerhard
105
E-print Network
Sensitized erbium emission from silicon-rich nitride/silicon superlattice structures L. Dal Negro,1 February 2008; accepted 16 April 2008; published online 7 May 2008 Erbium-doped silicon-rich nitride discovery of efficient resonant energy transfer be- tween Si nanocrystals Si-nc embedded in SiO2 and erbium
106
E-print Network
Erbium-doped and Raman microlasers on a silicon chip fabricated by the solÂgel process Lan Yang+ -doped solÂgel layers with control of the laser dynamics possible by varying the erbium concentration of the starting solÂgel material. Continuous lasing with a threshold of 660 nW for erbium-doped microlaser
Carmon, Tal
107
E-print Network
Characterization of an Erbium-Doped Fiber Amplifier as a Light Source and Development of a Near is amplified by the doped fiber. Furthermore, the output intensity of this erbium-doped fiber amplifier (EDFA by synergistic use of an erbium-doped fiber amplifier as a light source and an acoustooptic tunable filter
Reid, Scott A.
108
E-print Network
Chalcogenide-Bound Erbium Complexes: Paradigm Molecules for Infrared Fluorescence Emission G. A ReceiVed June 23, 2005 The near-infrared luminescence properties of the nanoscale erbium ceramic cluster (THF)14Er10S6- Se12I6 (Er10, where THF ) tetrahydrofuran) and the molecular erbium thiolate (DME)2Er
Lawson, Catherine L.
109
E-print Network
Active waveguide fabrication in erbium-doped oxyfluoride silicate glass using femtosecond pulses R September 2005 By directly writing waveguides inside bulk erbium-doped oxyfluoride silicate glass using and crystals.2 Recently, we have demonstrated that active waveguides may be fabricated inside erbium
110
E-print Network
Application of Robust L2 Control to Erbium Doped Fiber Amplifier: Input and State Uncertainty Nem nonlinear controller applied to an erbium doped fiber amplifier (EDFA). We consider the rejection of input controller of [9]. I. INTRODUCTION Regarded as the greatest innovation since optical fiber, the erbium doped
Pavel, Lacra
111
E-print Network
Spectroscopic signature of phosphate crystallization in Erbium-doped optical fibre preforms R, as structural modifier. In erbium ion (Er3+ ) doped fibres, phosphorus preferentially coordinates to Er3+ ions observed at room and low temperature are attributed to ErPO4 crystallites. Keywords : Erbium, Luminescence
112
E-print Network
Silver as a sensitizer for erbium C. Strohho¨fer and A. Polmana) FOM Institute for Atomic by the presence of silver. Samples prepared by a combination of erbium ion implantation and Na Ag ion exchange absorption cross sections of rare earth ions such as erbium or neodymium have spawned numerous at- tempts
Polman, Albert
113
E-print Network
Observation of enhanced photoluminescence in erbium-doped semiconductor microdisk resonator D. Y from an erbium-doped gallium phosphide microdisk resonator pumped by a Ti-sapphire laser at 980 nm sample. At low pumping power intensity, the photoluminescence from erbium-doped gallium phosphide
Ho, Seng-Tiong
114
E-print Network
for optical activity enhancement on Silicon nanocluster sensitized Erbium doped waveguide amplifier Hansuek-PON PON , , . (NC- Si EDWA: silicon nanocluster sensitized Erbium doped related to optical gain in erbium-doped silicon-rich silicon oxide waveguide amplifier," Appl. Phys. Lett
Park, Namkyoo
115
E-print Network
Stable and uniform multiwavelength erbium- doped fiber laser using nonlinear polarization rotation oscillations in an erbium-doped fiber laser is proposed and successfully demonstrated. The NPR effect by homogeneous gain broadening in erbium-doped fibers. Up to 28-wavelength lasing operation with wavelength
Wai, Ping-kong Alexander
116
E-print Network
Gain characteristics of a 210 km hybrid Raman/erbium-doped fiber amplified loop Gaston E. Tudury a of combining gain from Raman amplifiers and erbium-doped fiber amplifiers (EDFAs) in a fiber recir- culating and erbium-doped fiber amplifier (EDFA) gain media together to eliminate the gain tilt, removing the need
Maryland, Baltimore County, University of
117
E-print Network
Tunable silicon-based light sources using erbium doped liquid crystals S. M. Weissa Department for the tunable light sources consist of porous silicon microcavities infiltrated with erbium doped nematic liquid crystals. Erbium ions are the luminescence source, porous silicon microcavities narrow the emission band
Weiss, Sharon
118
E-print Network
Implementation of three functional devices using Erbium- doped Fibers: An Advanced Photonics Lab at the undergraduate students' level. The experiment uses erbium-doped fiber to implement three functions through the erbium-doped fiber amplified spontaneous emission (ASE) and characterize its emission spectrum; ii
Qian, Li
119
E-print Network
Achieving optical gain in waveguide-confined nanocluster-sensitized erbium by pulsed excitation for optical gain in nanocluster sensitized erbium in a slot waveguide geometry. We determine the viability to erbium. We show that pulsed excitation of a 10 nm layer achieves a modal gain of 0.9 dB/cm during each
Atwater, Harry
120
E-print Network
Structural properties and electrical characteristics of electron-beam gun evaporated erbium oxide of another rare-earth metal oxide, erbium oxide, Er2O3 . This material is rather well known as an optical it causes less of an erbium silicate in comparison with Gd2O3 and Y2O3 under similar annealing conditions
121
E-print Network
MO-PECVD (METAL-ORGANIC PLASMA ENHANCED CHEMICAL VAPOUR DEPOSITION) OF ERBIUM-DOPED HYDROGENATED-PECVD (Metal-Organic Plasma Enhanced Chemical Vapour Deposition) of Erbium-Doped Hydrogenated and Deuterated Sr. Department of Electrical and Computer Engineering, University of Toronto Abstract Erbium (Er3
Qian, Li
122
E-print Network
Gain Scheduling Control Design of an Erbium-Doped Fibre Amplifier by Pump Compensation Min Ding) transmission network produces undesirable transients in the existing channels due to erbium-doped fibre the effectiveness of the gain scheduling scheme. I. INTRODUCTION Erbium-doped fibre amplifiers (EDFA's) provide low
Pavel, Lacra
123
E-print Network
Erbium: A Deterministic, Concurrent Intermediate Representation for Portable and Scalable language, and for just-in-time compilation of bytecode languages. This paper introduces Erbium of Erbium, relying on a pro- totype implementation in GCC 4.3. Categories and Subject Descriptors: D.3
Boyer, Edmond
124
E-print Network
Enhanced light emission in photonic crystal nanocavities with Erbium-doped silicon nanocrystals in silicon membranes covered by thermally annealed silicon-rich nitride films with Erbium-doped silicon. The nanocavities were carefully designed in order to enhance emission from the nanocrystal sensitized Erbium
Vuckovic, Jelena
125
E-print Network
fs erbium-doped fiber laser mode locked with a cellulose polymer film containing single-wall carbonPassively harmonic mode locked erbium doped fiber soliton laser with carbon nanotubes based.ac.uk Abstract: We have proposed and demonstrated passive harmonic mode locking of an erbium doped fiber laser
Turitsyn, Sergei K.
126
E-print Network
862 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 20, NO. 5, MAY 2002 Design and Performance of an Erbium silicon-on-in- sulator material, and consists of an erbium-doped pÂn junction lo- cated in the core measurements on an erbium-doped Si wave- guide detector at room temperature show a clear erbium related
Polman, Albert
127
In this paper the doping of erbium from thin layers deposited on the LiNbO3 surface with an emphasis on the relations between changes in the LiNbO3 structure and the luminescence properties of Er:LiNbO3 have been studied. The erbium-containing layers were primarily characterised in terms of the luminescence at 1.5 ?m. The obtained results showed a high level of structural ordering in the samples after indiffusion of Er at high-temperature. This was apparent from the luminescence results, where more than 6 quite narrow luminescence bands were found, and also from the RBS/channeling analysis which showed, that the doped structure has similar degree of ordering as the bulk crystal LiNbO3. In terms of luminescence intensity at 1.5 ?m a better source for the erbium doping seems to be the erbium oxide layer. The highest luminescence intensity values were among the cuts achieved in the Z cut.
Nekvindova, P.; Cajzl, J.; Svecova, B.; Mackova, A.; Malinsky, P.; Oswald, J.; Vacik, J.; Spirkova, J.
2013-12-01
128
Rare earth doped III-nitrides have been intensively studied due to their intra-4f transitions covering the window from visible emissions to infrared wavelengths. Trivalent Erbium (Er^3+) has driven particular interests since the intra-4f transition from its first excited (^4I13/2) to the ground state (^4I15/2) gives 1.54 ?m emission, which sits in the low optical loss band of silica fibers and potentially affords light emitters and optical amplifiers at optical communication wavelength. Due to the structural and thermal stability of GaN, GaN appears to be the promising candidate as the host semiconductors. We prepared Er doped GaN (GaN:Er) samples by metal organic chemical vapor deposition. GaN:Er epilayers were simultaneously grown on different templates, including GaN/Al2O3, AlN/Al2O3, GaN/Si(111), and c-GaN bulk. The effects of stress, caused by the lattice mismatch between GaN:Er epilayers and the substrates, on the intensity of 1.54 ?m emission were probed. The emission intensity at 1.54 ?m increased with greater tensile stress in the c-direction of GaN:Er epilayers. The correlation between stress and 1.54 ?m emission will be presented. The results implied the potential to design efficient photonic devices based on GaN:Er semiconductors.
Feng, I.-Wen; Li, Jing; Sedhain, Ashok; Lin, Jingyu; Jiang, Hongxing; Zavada, John
2011-03-01
129
SciTech Connect
Brumbach, Michael T.; Ohlhausen, James A. [Materials Characterization Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Zavadil, Kevin R. [Materials Reliability Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Snow, Clark S. [Applied Science and Technology Maturation Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Woicik, Joseph C. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
2011-06-01
130
SciTech Connect
M Brumbach; j Ohlhausen; K Zavadil; C Snow; J Woicik
2011-12-31
131
Enhancing the optical absorption cross-section in topically important rare earth doped tellurite glasses is challenging for photonic devices. Controlled synthesis and detailed characterizations of the optical properties of these glasses are important for the optimization. The influence of varying concentration of Er3+ ions on the absorbance characteristics of lead tellurite glasses synthesized via melt-quenching technique are investigated. The UV-Vis absorption spectra exhibits six prominent peaks centered at 490, 526, 652, 800, 982 and 1520 nm ascribed to the transitions in erbium ion from the ground state to the excited states 4F7/2, 2H11/2, 4F9/2, 4I9/2, 2H11/2 and 4I13/2, respectively. The results are analyzed by means of optical band gap Eg and Urbach energy Eu. The values of the energy band gap are found decreased from 2.82 to 2.51 eV and the Urbach energy increased from 0.15 to 0.24 eV with the increase of the Er2O3 concentration from 0 to 1.5 mol%. The excellent absorbance of the prepared tellurite glasses makes them suitable for fabricating solid state lasers.
Sazali, E. S.; Rohani, M. S.; Sahar, M. R.; Arifin, R.; Ghoshal, S. K.; Hamzah, K.
2014-09-01
132
SciTech Connect
Erbium hydride thin films are grown onto polished, a-axis {alpha} Al{sub 2}O{sub 3} (sapphire) substrates by reactive ion beam sputtering and analyzed to determine composition, phase and microstructure. Erbium is sputtered while maintaining a H{sub 2} partial pressure of 1.4 x 10{sup {minus}4} Torr. Growth is conducted at several substrate temperatures between 30 and 500 C. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analyses after deposition show that the H/Er areal density ratio is approximately 3:1 for growth temperatures of 30, 150 and 275 C, while for growth above {approximately}430 C, the ratio of hydrogen to metal is closer to 2:1. However, x-ray diffraction shows that all films have a cubic metal sublattice structure corresponding to that of ErH{sub 2}. RBS and Auger electron that sputtered erbium hydride thin films are relatively free of impurities.
ADAMS,DAVID P.; ROMERO,JUAN A.; RODRIGUEZ,MARK A.; FLORO,JERROLD A.; BANKS,JAMES C.
2000-05-10
133
PubMed
Laser skin resurfacing has become increasingly popular. The carbon dioxide (CO2) laser seemingly remains the most commonly used laser modality for skin resurfacing. Many surgeons still promote the CO2 laser as being superior to the erbium:YAG laser, particularly for individuals with deeper lines. However, further experience with the erbium:YAG laser has shown the converse to be true. The erbium:YAG laser can be used to treat deep rhytids successfully, many times achieving results superior to those seen with the CO2 laser, particularly in the perioral region. The theory behind this relates to the 10-fold greater absorption of the erbium:YAG wavelength by water. The greater absorption produces more efficient vaporization, even at low fluences, with greatly reduced adjacent thermal injury. Ablation can be carried to deeper levels of the dermis than is consistently safe with the CO2 laser. Deliverance of total fluences in the range of 100 to 150 J/cm2, or more, produces a marked reduction or elimination of deeper rhytids. Clinically, experience with more than 300 cases indicates collagen remodeling occurs to a similar degree with the erbium:YAG laser as with the CO2 laser, as improvement in rhytids can be seen for 2 to 3 months after surgery. It would appear that superior results can be obtained without the "heat effect" of the CO2 laser. The erbium:YAG laser is capable of achieving superior resurfacing results, while offering many advantages to the patient, eg, reduced anesthetic requirements, shorter healing time, reduced erythema, less risk of pigmentary change, and more flexibility for resurfacing the skin off of the face. PMID:12437434
Jasin, Michael E
2002-01-01
134
The photoluminescence spectrum of erbium nitrate hydrate is analyzed. The dispersion dependencies of polaritonic waves in erbium nitrate hydrate are established by means of a model of the interaction between electromagnetic waves and resonance electronic states of Er3+ ions. The positions of unitary polaritons, for which the refraction index is unity, are established. Velocity and effective mass of unitary polaritons are calculated. Our research allows construction of a liquid-core laser. The calculations show an increase of pump efficiency in such a laser.
Gorelik, V. S.; Burdanova, M. G.
2014-12-01
135
SciTech Connect
Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.
Zavadil, Kevin Robert; Snow, Clark Sheldon; Ohlhausen, James Anthony; Brumbach, Michael Todd
2010-10-01
136
E-print Network
Atomic and molecular samples reduced to temperatures below 1 microkelvin, yet still in the gas phase, afford unprecedented energy resolution in probing and manipulating how their constituent particles interact with one another. For simple atoms, such as alkalis, scattering resonances are extremely well-characterized. However, ultracold physics is now poised to enter a new regime, where far more complex species can be cooled and studied, including magnetic lanthanide atoms and even molecules. For molecules, it has been speculated that a dense forest of resonances in ultracold collision cross sections will likely express essentially random fluctuations, much as the observed energy spectra of nuclear scattering do. According to the Bohigas-Giannoni-Schmit conjecture, these fluctuations would imply chaotic dynamics of the underlying classical motion driving the collision. This would provide a paradigm shift in ultracold atomic and molecular physics, necessitating new ways of looking at the fundamental interactions of atoms in this regime, as well as perhaps new chaos-driven states of ultracold matter. In this report we provide the first experimental demonstration that random spectra are indeed found at ultralow temperatures. In the experiment, an ultracold gas of erbium atoms is shown to exhibit many Fano-Feshbach resonances, for bosons on the order of 3 per gauss. Analysis of their statistics verifies that their distribution of nearest-neighbor spacings is what one would expect from random matrix theory. The density and statistics of these resonances are explained by fully-quantum mechanical scattering calculations that locate their origin in the anisotropy of the atoms' potential energy surface. Our results therefore reveal for the first time chaotic behavior in the native interaction between ultracold atoms.
Albert Frisch; Michael Mark; Kiyotaka Aikawa; Francesca Ferlaino; John L. Bohn; Constantinos Makrides; Alexander Petrov; Svetlana Kotochigova
2013-12-06
137
ERIC Educational Resources Information Center
This document is the laboratory manual for the Physics 152 course at Purdue University. It includes a laboratory introduction, hardware and software guide, and laboratory report guide. Labs include: (1) "Measurement Uncertainty and Propagation"; (2) "Introduction to Computer Data Acquisition and Relationships between Position, Velocity, and…
MacIssac, Dan; And Others
138
background. Melasma is a facial dyspigmentation which is a common complaint in patients with darker skin tones. Many current therapies used for this condition are ineffective and can cause significant adverse effects. objective. The purpose of this study was to evaluate the role of erbium:YAG laser resurfacing in the management of refrac- tory melasma. methods. Ten female patients with melasma
Rhesa May P. Manaloto; Tina Alster
1999-01-01
139
An accurate model for the erbium-doped fiber amplifier is presented. The model is used to design the index profile of the doped fiber, optimizing with regard to efficiency for inline- and preamplifiers as well as for power booster amplifiers. The predicted pump efficiencies (maximum gain to pump power ratios) are in agreement with experimental results presented in the literature. The
Bo Pedersen; Anders Bjarklev; J. H. Povlsen; Kristen Dybdal; Carl Christian Larsen
1991-01-01
140
Wavelength-locked, six-channel, colasing operation using a single gain medium is reported for the first time. The system is an all-fiber, erbium-amplifier-based design that uses a grating wavelength division multiplexer with a fixed channel spacing of 4.8 nm for frequency selection. The authors investigate two possible configurations for the laser cavity
J. W. Dawson; K. J. Vahala
1992-01-01
141
Simultaneous multiwavelength lasing is demonstrated exploiting intracavity polarization hole burning in an erbium-doped fiber laser. Experimental results indicate that polarization hole burning can be enhanced by the changes of the light polarization states and bias current of optical MQW waveguide which serves as reflector in the laser. Eleven wavelengths with 0.9 nm spacing are generated at room temperature.
Junqiang Sun; Junlin Qiu; Dexiu Huang
2000-01-01
142
An analytic method is described for fully characterizing the gain of an erbium-doped fiber amplifier (EDFA) that is based on easily measured monochromatic absorption data. The analytic expressions presented, which involve the solution of one transcendental equation, can predict signal gains and pump absorptions in an amplifier containing an arbitrary number of pumps and signals from arbitrary directions. The gain
A. A. M. Saleh; R. M. Jopson; J. D. Evankow; J. Aspell
1990-01-01
143
The purpose of the study was to evaluate the effect of erbium (Er): yttrium aluminum garnet (YAG) laser trabecular ablation with a sapphire optical fiber on outflow facility.After obtaining baseline outflow facility using a computerized differential pressure perfusion system, human cadaver eyes were subjected to Er: YAG laser trabecular ablation using a sapphire optical fiber. Single pulses at varying energy
M. LISA McHAM; DAN L. EISENBERG; JOEL S. SCHUMAN; NAN WANG
1997-01-01
144
E-print Network
Currently, 31 dysprosium, 32 holmium, 32 erbium, 33 thulium and 31 ytterbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
C. Fry; M. Thoennessen
2012-05-26
145
E-print Network
Currently, 31 dysprosium, 32 holmium, 32 erbium, 33 thulium and 31 ytterbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Fry, C
2012-01-01
146
SciTech Connect
Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Fry, C.; Thoennessen, M., E-mail: [email protected]
2013-09-15
147
Code of Federal Regulations, 2011 CFR
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2010-10-01
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...2010-04-01 2010-04-01 false Bona-fide gifts. 10.152 Section 10.152 Customs Duties...Provisions Importations Not over $200 and Bona Fide Gifts § 10.152 Bona-fide gifts. Subject to the conditions in §... 2010-04-01 173 Code of Federal Regulations, 2010 CFR ...2010-01-01 2010-01-01 false Notice of delay or acceleration. 152.321 Section 152.321 Aeronautics and Space...Reporting Requirements § 152.321 Notice of delay or acceleration. (a) The sponsor or planning agency shall... 2010-01-01 174 Code of Federal Regulations, 2011 CFR ...2011-01-01 2011-01-01 false Notice of delay or acceleration. 152.321 Section 152.321 Aeronautics and Space...Reporting Requirements § 152.321 Notice of delay or acceleration. (a) The sponsor or planning agency shall... 2011-01-01 175 Code of Federal Regulations, 2013 CFR ...2013-01-01 2013-01-01 false Notice of delay or acceleration. 152.321 Section 152.321 Aeronautics and Space...Reporting Requirements § 152.321 Notice of delay or acceleration. 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Tax-free alcohol may... 2011-04-01 189 Code of Federal Regulations, 2010 CFR ...2010-10-01 2010-10-01 false Availability of funds. 152.3 Section 152...FIREFIGHTERS GRANT PROGRAM § 152.3 Availability of funds. (a) Fire departments...communities (urban, suburban or rural) as well as an equitable geographic... 2010-10-01 190 Code of Federal Regulations, 2012 CFR ...2012-07-01 2012-07-01 false Claims for death benefits. 3.152 Section 3.152...Compensation Claims § 3.152 Claims for death benefits. (a) A specific claim...3.153) must be filed in order for death benefits to be paid to any... 2012-07-01 191 Code of Federal Regulations, 2013 CFR ...2013-07-01 2013-07-01 false Claims for death benefits. 3.152 Section 3.152...Compensation Claims § 3.152 Claims for death benefits. (a) A specific claim...3.153) must be filed in order for death benefits to be paid to any... 2013-07-01 192 E-print Network 116. DÃ?SINTÃ?GRATION DE QUELQUES ISOTOPES D'ERBIUM ET D'HOLMIUM DÃ?FICIENTS EN NEUTRONS Par P principaux rayonnements 03B3 de 12 isotopes d'erbium ou d'holmium déficients en neutrons. Les résultats sont rays of 12 erbium or hol- mium neutron deficient isotopes have been measured. Results are discussed Paris-Sud XI, Université de 193 E-print Network Erbium-implanted silica microsphere laser J. Kalkman a,*, A. Polman a , T.J. Kippenberg b , K with erbium ions by ion implantation at energies of 925 keV and 2.05 MeV using a rotating stage. After thermal: 42.55.Sa; 42.60.Da; 42.81.Qb; 85.40.Ry Keywords: Microsphere; Laser; Erbium; Ion implantation 1 Polman, Albert 194 E-print Network LE JOURNAL DE PHYSIQUE ET LE RADIUM Ã?TUDE DE LA DÃ?SINTÃ?GRATION DE L'ERBIUM 169 Par G. CHARPAK et F 169, atteint par désin- tégration de l'erbium 169. On a obtenu pour la probabilité de désintégration of the low energy electron and photon spectrum of erbium 169. The branching ratio to the 8,4 keV excited Boyer, Edmond 195 E-print Network 33 SUR LES SPECTRES DE L'YTTRIUM, DE L'ERBIUM, DU DIDYME ET DU LANTHANE, PAR M. ROB. THALÃ?N,~=ttriuln, erbium, etc. e j~ . Le but principal de la recherche em question fut de contrôler, au moyen de l'analysespectrale, s'il a été possible aux chimistes de sé- parer entre ceux les sels d'yttriuiii et d erbium. et (eux Paris-Sud XI, Université de 196 E-print Network Laser verre codopé Erbium et Ytterbium pompé par une diode laser de puissance Eric Tanguy CL lean proposé est fondé sur l'utilisation d'un verre codopé erbium et ytterbium pompé optiquement par unediode laser fibrée de puissanceet émettantvers 980 nm. Les lasers exploitant les propriétés de l'erbium et Paris-Sud XI, Université de 197 PubMed We present an erbium-doped dispersion-compensating fiber made up of two asymmetric concentric cores, inner and outer matched claddings, and erbium located in the central core only. We demonstrate a high negative chromatic dispersion value [-700 ps/(nm km) at 1568 nm], significant modification of the gain spectrum compared with that of a classic erbium-doped fiber amplifier, and 30-dB peak small-signal gain at 1535 and 1553 nm. PMID:15072363 Maury, J; Auguste, J L; Février, S; Blondy, J M; Dussardier, B; Monnom, G 2004-04-01 198 Microsoft Academic Search We have synthesized erbium-included mesoporous materials to enhance optical amplification gain in Er3+-doped silica materials. Various mesoporous materials such as MCM-41, MCM-48 or SBA-15 were prepared and then erbium ions were filled into the empty pores in the mesoporous materials via sol-gel process through the external modification of the mesoporous materials. All erbium-included mesoporous materials exhibit the near infrared emission Yun Hui Cha; Kyong-Soo Hong; Soon Chang Lee; Duck-Lae Joo; Jin Kook Lee; Jong-Sung Yu; Suk Bon Yoon; Hwan Kyu Kim 2004-01-01 199 DOEpatents Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of .sup.167 Er. The hyperfine structure of .sup.167 Er was used to find two three-step photoionization pathways having a common upper energy level. Haynam, Christopher A. (3035 Ferdale Ct., Pleasanton, CA 94566); Worden, Earl F. (117 Vereda del Ciervo, Diablo, CA 94528) 1995-01-01 200 Microsoft Academic Search The magnetic phases of erbium have been studied by resonance x-ray-scattering techniques. When the incident x-ray energy is tuned near the LIII absorption edge, large resonant enhancements of the magnetic scattering are observed above 18 K. We have measured the energy and polarization dependence of this magnetic scattering and analyzed it using a simple model based on electric dipole and M. K. Sanyal; Doon Gibbs; J. Bohr; M. Wulff 1994-01-01 201 Microsoft Academic Search We describe experimental results demonstrating the performance of the erbium-doped silica fiber as a remote temperature sensor in the temperature interval [21 C - 96 C]. We present the measured fluorescence spectrum corresponding to the energy levels 2H11\\/2 and 4S3\\/2. This sensor incorporates simple signal detection in a band and data analysis system, incorporating a power ratio to reduce noise Gonzalo Paez; Victor Lopez; Marija Strojnik 2003-01-01 202 Microsoft Academic Search Dynamic compensation of low-frequency gain fluctuations in saturated erbium-doped fiber amplifiers is demonstrated. This compensation, based on a simple feedback-loop scheme makes it possible to reduce transient gain fluctuations efficiently across the whole amplifier bandwidth using only a low-power optical feedback signal. Such an, automatic gain control technique could be applied to suppress data packet interference due to traffic bursts E. Desurvire; M. Zirngibl; H. M. Presby; D. Digiovanni 1991-01-01 203 Microsoft Academic Search The gain and pumping efficiency of aluminosilicate erbium-doped fiber amplifiers (EDFAs) are analyzed as a function of guiding parameters and Er-doping profile for two pump wavelengths of ? p=980 nm and ?p=1.47 ?m. Three designs of fiber-amplifier waveguides are considered: one with the same mode size as standard 1.5-?m communication fibers (type 1); one with the same mode size as E. Desurvire; J. L. Zyskind; C. R. Giles 1990-01-01 204 Microsoft Academic Search An optical notch filter was incorporated within the length of all erbium-doped fiber amplifier. Careful choice of the filter characteristics and location made it possible to enhance the amplifier gain at wavelengths around 1550 nm. An amplifier with 27-dB gain and 33-nm bandwidth was demonstrated. The saturation characteristics of the amplifier were uniform across its gain spectrum, making it ideal M. Tachibana; R. I. Laming; P. R. Morkel; D. N. Payne 1991-01-01 205 DOEpatents Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of {sup 167}Er. The hyperfine structure of {sup 167}Er was used to find two three-step photoionization pathways having a common upper energy level. 3 figs. Haynam, C.A.; Worden, E.F. 1995-08-22 206 E-print Network Erbium-Doped Fiber Laser With a Multimode Fiber Bragg Grating and Photonic Crystal Fiber Xinhuan Feng, a simple switchable multiwavelength erbium-doped fiber laser is proposed and demonstrated. The wavelengths or wavelength switching modes by varying the states of polarizations of the laser cavity. Index Terms--Erbium Wai, Ping-kong Alexander 207 E-print Network IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 18, NO. 14, JULY 15, 2006 1515 Internal Gain From an Erbium, Animesh Jha, and Ajoy K. Kar, Member, IEEE Abstract--A channel waveguide is fabricated inside an erbium for the first time. Erbium (Er)-doped waveguide amplifiers (EDWAs) ex- hibiting impressive performance have 208 E-print Network March 1, 1999 / Vol. 24, No. 5 / OPTICS LETTERS 279 Passive erbium-doped fiber seed photon is suggested for a high-power erbium-doped fiber (EDF) broadband source. A considerable increase in output (ASE) from an erbium- doped fiber (EDF) have been considered to be one of the optimum candidates Park, Namkyoo 209 E-print Network Ultra-flat spectrum, multiwavelength operation in an erbium-doped fiber laser using power to realize multiwavelength oscillations in erbium- doped fiber lasers (EDFLs) [1-2]. In this work, we propose. The amplifying unidirectional loop consists of a commercial high power erbium-doped fiber amplifier (EDFA Wai, Ping-kong Alexander 210 E-print Network OME14 La-codoped Bismuth-based Erbium-doped Fiber Ring Laser with 106-nm Tuning Range H. L. Liu, H component characterization. Silica-based erbium-doped fibers (Si-EDFs) are commonly employed as gain medium the concentration of erbium ions that can be doped into silicate fiber and therefore long length of Si Wai, Ping-kong Alexander 211 E-print Network January 1, 1997 / Vol. 22, No. 1 / OPTICS LETTERS 13 Frequency doubling of femtosecond erbium efficient frequency doubling of passively mode-locked femtosecond erbium-fiber lasers. Quasi- phase Diode-pumped passively mode-locked erbium-doped- fiber lasers (EDFL's) are compact and flexible sources Fejer, Martin M. 212 E-print Network 53-Line Multi-wavelength Generation in Brillouin/Erbium Fiber Laser with Enhanced Stokes Feedback will be described. ThA4-1 #12;53-Line Multi-wavelength Generation of Brillouin/Erbium Fiber Laser with Enhanced lasers. Of these, a hybrid Brillouin/Erbium fiber laser (BEFL) with feedback scheme is one of the strong Park, Namkyoo 213 E-print Network 756 IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 17, NO. 4, APRIL 2005 Multiwavelength Erbium, Zhichao Deng, and Jian Liu, Member, IEEE Abstract--A novel room-temperature multiwavelength erbium- doped and wavelength spacing as small as 0.19 nm is demonstrated at room temperature. Index Terms--Erbium-doped fiber Yao, Jianping 214 E-print Network C- and L-band erbium-doped waveguide lasers with wafer-scale silicon nitride cavities Purnawirman,1; posted April 22, 2013 (Doc. ID 187023); published May 20, 2013 We report on integrated erbium and a top erbium-doped aluminum oxide layer deposited as the final step in the fabrication process Reif, Rafael 215 E-print Network Topic (PIS) Code : OMNO Presentation Preference : Oral (invited) IN-SITU GROWN ERBIUM in fabrication, respectively. Erbium and alkaline-earth ions (Mg, Ca and Sr) were incorporated through the wellB/m only. This value is compatible with amplifier applications. The spectroscopic properties of erbium ions Paris-Sud XI, Université de 216 E-print Network Silicon nanocrystals in erbium-doped silica for optical amplifiers F. Lucarz and A.J Kenyon pumped at room temperature, nanometer-sized silicon crystals embedded in erbium-doped silica can be used as efficient sensitisers for Er3+ ions, leading to enhanced photoluminescence from erbium at 1540 nm Haddadi, Hamed 217 E-print Network Abstract-- A novel multiwavelength erbium-doped fiber laser (EDFL) based on two comb filters broadening of the erbium-doped fiber (EDF). As a result, triple-wavelength lasing operation with wavelengthB. I. INTRODUCTION Multiwavelength erbium-doped fiber lasers (EDFLs) are useful light sources for WDM Wai, Ping-kong Alexander 218 E-print Network Microscopic structure and energy transfer of vacancy-related defect pairs with Erbium in wide Available online 12 February 2011 Keywords: Erbium SiC GaN EPR a b s t r a c t Electron Paramagnetic Resonance (EPR) measurements of Erbium-doped 6HÂSiC and wurtzite GaN sam- ples are compared to total energy Schmidt, Wolf Gero 219 E-print Network Erbium-doped silicon nanocrystals in silicon/silicon nitride superlattice structures: Light ($2 nm diameter) amorphous silicon (Si) clusters coupled to erbium (Er) ions. The superlattice emission with nanosecond-fast dynamics, small temperature quenching and efficient energy transfer to erbium
220
E-print Network
La-codoped Bismuth-based Erbium-doped Fiber Ring laser with 80-nm Tuning Range H. L. Liu1 , H. Y tunable fiber ring lasers using 253.3-cm long La-codoped bismuth-based erbium doped fiber and a narrowband allowing fast component characterization. Silica-based erbium-doped fibers (Si-EDFs) are commonly employed
Wai, Ping-kong Alexander
221
E-print Network
All-optical clock recovery using erbium-doped fiber ring laser incorporating an electro, Hung Hom, Hong Kong Abstract We demonstrated 10-GHz all-optical clock recovery using an erbium-optical clock recovery which composes of an EAM, an LOA, a 12 meter long erbium-doped fiber, a bandpass filter
Wai, Ping-kong Alexander
222
E-print Network
Synthesis, Structure, and Molecular Orbital Studies of Yttrium, Erbium, and Lutetium Complexes procedure, the reaction of erbium metal with 3,5-dialkylpyrazole (alkyl ) methyl or tert-butyl), bis-tert-butylpyrazole) yielded tris(3,5-di-tert-butylpyrazolato)bis(4-tert-butylpy- ridine)erbium(III) (63%), tris(3,5-di-tert-butylpyrazolato)bis(pyridine)erbium
Schlegel, H. Bernhard
223
E-print Network
ERBIUM-DOPED WET OXIDES OF AlGaAs AND InAlP ON GaAs SUBSTRATES FOR OPTOELECTRONIC INTEGRATION;ERBIUM-DOPED WET OXIDES OF AlGaAs AND InAlP ON GaAs SUBSTRATES FOR OPTOELECTRONIC INTEGRATION Abstract of luminescence properties of Erbium ....................................... 3 1.3 Review of Erbium host materials
224
E-print Network
Degradation model for erbium-doped fiber amplifiers to reduce network downtime Christian Merkle optical amplifiers and cross connects reduces the availability of a network and increases the operational of erbium-doped amplifiers (EDFAs) can be used to reduce the repair time by changing an EDFA before it fails
225
SciTech Connect
We report cladding-pumped erbium-doped fibre laser and amplifier configurations. Through fibre design optimisation, we have achieved a record-high laser slope efficiency, 40 % with respect to absorbed pump power ({lambda} = 976 nm), and an output power of 7.5 W. The erbium-doped fibre amplifier efficiency reaches 32 %.
Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Lipatov, D S; Vechkanov, N N; Guryanov, Aleksei N
2012-05-31
226
E-print Network
Femtosecond soliton collapse and coherent pulse train generation in erbium-doped fiber amplifiers 1 collapse and pulse train generation in erbium-doped fiber amplifiers is examined. The amplification of ultrashort pulses in laser amplifi- ers is a well established field of physics and technology.' Nevertheless
Gabitov, Ildar
227
The effects of erbium anisotropy in erbium-doped fiber lasers, sources, and amplifiers are examined. Starting from basic ion properties, inversion and gain equations are derived analytically to describe polarization dependencies. A novel matrix form of the Er3+ rate equations is presented to propagate powers and polarization states. These equations are then numerically integrated and compared to experimentally observed polarization hole
Jefferson L. Wagener; Dario G. Falquier; J. J. F. Digonnet; Herbert J. Shaw
1998-01-01
228
Experiments to determine the effects of exposure to ionizing radiation and hydrogen on erbium fibers and erbium fiber amplifiers are described. A preliminary assignment of the radiation induced losses to components of the fiber composition is made. Both reversible and long term losses resulting from hydrogen permeation have been observed. As in other types of fibers, the presence of hydrogen
Ronald H. West; Stuart Dowling; Richard Lewis; Ed S. Sikora; John V. Wright
1993-01-01
229
Recent results obtained for SiO2-HfO2: Er3+ and SiO2-TiO2: Er3+-Yb3+ waveguides are presented. (100-x)SiO2-xHfO2 (x = 10, 20, 30, 40 mol) planar waveguides, doped with 0.01 and 0.3 mol % Er3+ ions were prepared by sol-gel route, using dip-coating deposition on v-SiO2 substrates. The waveguides were characterized by m-line, Raman and photoluminescence spectroscopy. The spectral shape of the band assigned to the 4I13/2->4I15/2 transition does not change practically with the hafnium and erbium content. The 4I13/2 level decay curves present a single-exponential profile, with a lifetime between 5.5 and 7.1 ms, for the 0.3 mol% doped samples, and between 8.5 and 6.6 ms for the 0.01 mol% doped samples. The SiO2-TiO2: Er3+-Yb3+ waveguides were prepared by rf-sputtering technique. All waveguides were single-mode at 1550 nm. The losses, for the TE0 mode, were evaluated at 632.8 and 1300 nm and an attenuation coefficient equal or lower than 0.2 dB/cm was measured both at 632.8 nm and 1300 nm. The emission of 4I13/2->4I15/2 of Er3+ ion transition was observed upon excitation in the TE0 mode at 981 and 514.5 nm. Back energy transfer from Er3+ to Yb3+ was demonstrated by measurement of Yb3+ emission upon Er3+ excitation at 514.5 nm. Photoluminescence excitation spectroscopy was used to obtain information about the effective excitation efficiency of Er3+ ions by co-doping with Yb3+ ions.
Chiasera, Alessandro; Ferrari, Maurizio; Zampedri, Luca; Mattarelli, Maurizio; Montagna, Maurizio; Portales, Herve; Tosello, Cristiana; Dire, Sandra; Pelli, Stefano; Righini, Giancarlo C.
2004-08-01
230
In this paper, we demonstrate a wideband Bismuth-based erbium doped fiber amplifier (Bi-EDFA) using two pieces of bismuth-based erbium-doped fiber (Bi-EDF) with a total length of 67 cm as gain media in a double pass parallel configuration. Both Bi-EDFs have an erbium ion concentration of 6300 ppm. Compared to conventional silica-based erbium-doped fiber amplifier (Si-EDFA) with the same amount of erbium ions, the Bi-EDFA provides a higher attainable gain as well as a greater amplification bandwidth, which ranging from 1525 to 1620 nm. The proposed Bi-EDFA achieved a wideband gain of around 18 dB within the wavelength region from 1530 to 1565 nm. The noise figures are maintained below 10 dB within a wide wavelength region from 1535 nm to 1620 nm.
Cheng, X. S.; Hamida, B. A.; Naji, A. W.; Ahmad, H.; Harun, S. W.
2011-11-01
231
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E-print Network
Math 152: Linear Systems  Winter 2004 1: Vectors and Geometry Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Description of points and the geometry of solutions to systems of equations
Jellinek, Mark
234
Spin relaxation due to atom--atom collisions is measured for buffer-gas cooled and magnetically trapped erbium and thulium atoms at a temperature near 500 mK. The rate constants for Er--Er and Tm--Tm collisions are 3.0 x10-10 and 1.1 x10-10 cm^3 s-1, respectively, 2--3 orders of magnitude larger than those observed for highly magnetic S-state atoms. This is strong evidence for an
Colin B. Connolly; Yat Shan Au; S. Charles Doret; Wolfgang Ketterle; John M. Doyle
2010-01-01
235
NASA Technical Reports Server (NTRS)
The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed.
Hanna-Hawver, P.; Kamdar, K. D.; Mehta, S.; Nagarajan, S.; Nasta, M. H.; Claus, R. O.
1992-01-01
236
E-print Network
We investigate cooling mechanisms in magneto-optically and magnetically trapped erbium. We find efficient sub-Doppler cooling in our trap, which can persist even in large magnetic fields due to the near degeneracy of two Lande g factors. Furthermore, a continuously loaded magnetic trap is demonstrated where we observe temperatures below 25 microkelvin. These favorable cooling and trapping properties suggest a number of scientific possibilities for rare-earth atomic physics, including narrow linewidth laser cooling and spectroscopy, unique collision studies, and degenerate bosonic and fermionic gases with long-range magnetic dipole coupling.
Andrew J. Berglund; Siu Au Lee; Jabez J. McClelland
2008-02-06
237
The water pollution is a health problem around the world. One of the most common pollutants in water is the Ammonia. Some sensors have been developed for Ammoniac detection even though most of them are not in real time and could be expensive. In this work an Erbium-doped fibre-sensor for Ammonia detection with a mechanical long period fibre grating and a taper in cascade for improving the sensitivity; the detection bandwidth is in the 1550 nm region from 1460 nm to 1640 nm. Output optical spectrum for Ammonia concentrations from 1ml to 5 ml is shown
Pérez-Sánchez, G. G.; Pinzón-Escobar, E. F.; Sandoval-Romero, G. E.; Álvarez Chávez, J. A.
2015-01-01
238
Quantum memories for single photons could play an important role in quantum communication and optical quantum computing. We are working towards the realization of such a quantum memory based on the controlled reversible inhomogeneous broadening (CRIB) of a single absorption line in a rare earth ion. The implementation of the CRIB protocol for such a quantum memory requires a three level system such that the absorption over a broad bandwidth in a material can be greatly reduced via optical pumping to the auxiliary level. We report on the first experimental steps towards the realization of such a three level systems in Erbium doped materials with spectral hole burning techniques.
Hastings-Simon, Sara; Staudt, Matthias; Lauritzen, Bjoern; Afzelius, Mikael; de Riedmatten, Hugues; Sangouard, Nicolas; Simon, Christoph; Tittel, Wolfgang; Gisin, Nicolas
2007-03-01
239
Radiative lifetimes, accurate to ±5%, have been measured for 8 even-parity and 72 odd-parity levels of singly ionized erbium using time-resolved laser-induced fluorescence (LIF) on Er ions in a beam. This new set of measurements is more extensive than earlier LIF sets, and is in good agreement with those sets where they overlap. These lifetimes provide an absolute scale for a large, accurate set of Er \\\\sc II atomic transition probabilities. Basic spectroscopic data on rare earth transition probabilities are needed for astrophysical research and for research on lighting products.
Stockett, M. H.; Den Hartog, E. A.; Lawler, J. E.
2007-12-01
240
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We report the first observation of photoluminescence enhancement in Er3+ doped GeO2-Bi2O3 glasses containing silicon nanocrystals (Si-NCs) excited by a laser operating at 980 nm. The growth of ?200% in the intensity of the Er3+ transition 4S3/2?4I15/2 (545 nm) and of ?100% for transitions 2H11/2?4I15/2 (525 nm), 4F9/2?4I15/2 (660 nm), and 4I5/2?4I13/2 (1530 nm) was observed in comparison with a reference sample that does not contain Si-NCs. The results open a new road for obtaining efficient Stokes and anti-Stokes emissions in germanate composites doped with rare-earth ions.
da Silva, Diego S.; Naranjo, Luz P.; Kassab, Luciana R. P.; de Araújo, Cid B.
2012-03-01
250
PubMed
Site distributions of Er(3+)-doped aluminosilicate preforms of standard EDFA were studied by the low temperature Resonant Fluorescence Line Narrowing (RFLN) spectroscopy. Two erbium concentration samples with the same glass base were investigated. At very low erbium concentration, two classes of sites were identified, related to the number of AlO(6) octahedral linked by two oxygen edge-sharing to Er(3+) in the coordination sphere. As erbium concentration is increased, the high AlO(6) coordinated class of sites is smeared out by the optical response of the one AlO(6) coordinated class of sites. PMID:20940961
Peretti, R; Jurdyc, A M; Jacquier, B; Burov, E; Pastouret, A
2010-09-27
251
SciTech Connect
Photonic crystal nanocavities are fabricated in silicon membranes covered by thermally annealed silicon-rich nitride films with Erbium-doped silicon nanocrystals. Silicon nitride films were deposited by sputtering on top of silicon on insulator wafers. The nanocavities were carefully designed in order to enhance emission from the nanocrystal sensitized Erbium at the 1540 nm wavelength. Experimentally measured quality factors of {approx}6000 were found to be consistent theoretical predictions. The Purcell factor of 1.4 was estimated from the observed 20-fold enhancement of Erbium luminescence.
Makarova, Maria; Sih, Vanessa; Vuckovic, Jelena [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Warga, Joe; Li Rui; Dal Negro, Luca [Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States)
2008-04-21
252
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268
In this study, we investigated the luminescence properties of erbium-doped potassium tantalite niobate (KTaxNb1-xO3 or KTN) ceramics, which were prepared by the conventional solid-state reaction synthesis method. In this work, we studied the relationships of the crystal structure, and Raman and photoluminescence (PL) spectra with the tantalum concentration, respectively. The experiments showed that the tantalum dopants modified the intensity of the green, red and near-infrared emission bands. The experiments also showed a blue shift for the 2 mol % erbium doped KTN samples with different tantalum compositions. Doping Ta not only led to the change in PL intensity but also in spectral shapes. The PL spectra showed the splitting peaks for the samples with low Ta compositions. Then these peaks combined and broadened as Ta concentration increase. When Ta was substituted for Nb completely, the luminescence intensity of the green emission band had an increase of approximately about one order of magnitude, which was because of the absence of the first-order phonon relaxation in the high-Ta-concentration samples.
Wen, Cheng?Hung; Chu, Sheng?Yuan; Shin, Yan?Yu; Wen, Cheng?Kuo
2006-07-01
269
Er-Si-O crystalline thin film preparation on silicon substrates by using metal organic molecular beam epitaxy (MOMBE) is proposed. Tetra ethoxy silane (TEOS) and tris-2,2,6,6-tetra methyl-3,5-octane dionato erbium (Er(TMOD) 3) were used as Si-O and Er-O precursors, respectively. The Er-Si-O thin film crystallizes mainly during the post-annealing process and into a novel type of erbium-silicate crystalline compounds, which have not ever been reported. The atomic fraction of Er:Si:O in the prepared thin film is 3:2:8. The Er 3+ related PL spectra show a fine structure with a line width of less than 1 meV at 20 K and 4 meV at room temperature. The narrow line width is due to the crystalline nature. In addition, the PL spectrum fine structure observed in these Er-Si-O films has reproduced the fine structure observed in Er-Si-O crystallites prepared by the wet-chemical method reported by Isshiki et al. The present results have proved that the method proposed in this paper is effective to form Er-Si-O crystalline films.
Masaki, K.; Isshiki, H.; Kimura, T.
2005-02-01
270
PubMed
We demonstrate for the first time a radiation-resistant Erbium-Doped Fiber exhibiting performances that can fill the requirements of Erbium-Doped Fiber Amplifiers for space applications. This is based on an Aluminum co-doping atom reduction enabled by Nanoparticules Doping-Process. For this purpose, we developed several fibers containing very different erbium and aluminum concentrations, and tested them in the same optical amplifier configuration. This work allows to bring to the fore a highly radiation resistant Erbium-doped pure silica optical fiber exhibiting a low quenching level. This result is an important step as the EDFA is increasingly recognized as an enabling technology for the extensive use of photonic sub-systems in future satellites. PMID:22330481
Thomas, Jérémie; Myara, Mikhaël; Troussellier, Laurent; Burov, Ekaterina; Pastouret, Alain; Boivin, David; Mélin, Gilles; Gilard, Olivier; Sotom, Michel; Signoret, Philippe
2012-01-30
271
E-print Network
In this thesis, Silicon-Germanium (SiGe) Saturable Bragg Reflectors (SBR) and Erbium-doped waveguide chips are fabricated and characterized as crucial components for integration of a mode-locked laser on a Si-chip. The ...
Byun, Hyunil
2006-01-01
272
E-print Network
A 301 MHz fundamentally mode-locked erbium fiber ring laser generating 108 fs pulses is demonstrated. Novel combination of gain fiber with anomalous group-velocity dispersion and intra-cavity silicon with normal group-velocity ...
Ippen, Erich P.
273
E-print Network
The structural and photoluminescence properties of ytterbium-erbium silicate thin films have been investigated. The films were fabricated by RF-magnetron co-sputtering of Er[subscript 2]O[subscript 3], Yb[subscript ...
Kimerling, Lionel C.
274
SciTech Connect
We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters.
Kenyon, A. J.; Wojdak, M.; Ahmad, I.; Loh, W. H.; Oton, C. J. [Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Optoelectronics Research Centre, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)
2008-01-15
275
A multi-wavelength Brillouin Raman erbium-doped fiber laser is proposed and demonstrated. The setup uses a 7.7 km dispersion compensating fiber simultaneously as the Brillouin and Raman nonlinear gain media and operates in conjunction with a 3 m erbium-doped fiber as the linear gain medium. At a Brillouin pump (BP) wavelength of 1530 nm, where Raman and erbium gains overlap each other, 34 Brillouin Stokes lines having line spacing of 0.075 nm are created by using a Raman pump power of only 24.1 dBm, an erbium pump power of about 22.1 dBm, and a BP power of 6.5 dBm in the proposed linear cavity. The system is highly efficient and is able to generate many comparable peak-power lines at a low pump power.
Shirazi, M. R.; Harun, S. W.; Ahmad, H.
2014-03-01
276
Optical gain at 1.54 mum in erbium-doped silicon-rich silicon oxide (SRSO) is demonstrated. Er-doped SRSO thin film was fabricated by electron-cyclotron resonance enhanced chemical vapor deposition of silicon suboxide with concurrent sputtering of erbium followed by a 5 min anneal at 1000 °C. Ridge-type single mode waveguides were fabricated by wet chemical etching. Optical gain of 4 dB\\/cm of an
Hak-Seung Han; Se-Young Seo; Jung H. Shin
2001-01-01
277
The main reasons for and the results of switching to uranium-erbium fuel in the units of the Lengingrad, Kursk, and Smolensk\\u000a nuclear power plants are presented. It is shown that uranium-erbium fuel made it possible to regulate the steam coefficient\\u000a of reactivity, upgrade the control rods, lower the power density in the core, increase the reliability of the fuel assemblies,
A. A. Bystrikov; A. K. Egorov; V. I. Ivanov; E. V. Burlakov; A. V. Krayushkin; A. M. Fedosov; A. I. Kupalov-Yaropolk; V. M. Panin; Yu. M. Cherkashov
2006-01-01
278
DOEpatents
A resonantly photo-pumped X-ray laser (10) that enhances the gain of seve laser lines that also lase because of collisional excitations and recombination processes, is described. The laser comprises an aluminum (12) and erbium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like erbium ions (34) are resonantly photo-pumped by line emission from hydrogen-like aluminum ions (32).
Nilsen, Joseph (Livermore, CA)
1990-01-01
279
It is shown that in low-concentration erbium-doped silicate fibers (below 1000 p.p.m.), a residual absorption at 980 nm cannot be saturated. Usual models for upconversion of Er3+ cannot match this behavior nor explain a fluorescence lifetime independent of pump power and erbium concentration. A phenomenon, the pair induced quenching (PIQ), that is compatible with the previous experimental results is exhibited.
E. Delevaque; T. Georges; M. Monerie; P. Lamouler; J.-F. Bayon
1993-01-01
280
Experiments to determine the effects of exposure to ionizing radiation and hydrogen on erbium fibers and erbium fiber amplifiers are described. A preliminary assignment of the radiation induced losses to components of the fiber composition is made. Both reversible and long term losses resulting from hydrogen permeation have been observed. As in other types of fibers, the presence of hydrogen modifies the response to radiation.
West, Ronald H.; Dowling, Stuart; Lewis, Richard; Sikora, Ed S.; Wright, John V.
1993-02-01
281
E-print Network
INTERPR�TATION DE L'AIMANTATION DU GALLATE D'ERBIUM EN CHAMP FORT ET A BASSE TEMP�RATURE Par Y'interprétation des spectres d'absorp- tion optique du gallate d'erbium, permet également d'expliquer les propriétés. - The crystalline field model wich gives a good interpretation of the optical absorp- tion spectra of erbium gallium
282
E-print Network
Sub-100 fs mode-locked erbium-doped fiber laser using a 45°-tilted fiber grating Zuxing Zhang demonstrate generation of sub-100 fs pulses at 1.5 µm in a mode-locked erbium-doped fiber laser using a 45.3510) Lasers, erbium; (140.4050) Mode- locked lasers. References and links 1. H. A. Haus, K. Tamura, L. E
Turitsyn, Sergei K.
283
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Erbium lasers emitting at 2.94 micrometers and holmium lasers emitting at 2.1 micrometers are interesting tools for cutting, drilling, smoothing and welding of water containing tissues. The high absorption coefficient of water at these wavelengths leads to their good ablation efficiency with controlled thermally altered zones around the ablation sites. Combination of pulses with both wavelengths transmitted through one fiber were used to perform incisions in soft tissue and impacts in bone disks. Histological results and scanning electron microscope evaluations reveal the strong influence of the absorption coefficient on tissue effects, especially on the ablation efficiency and the zone of thermally damaged tissue. It is demonstrated that the combination of high ablation rates and deep coagulation zones can be achieved. The results indicate that this laser system can be considered as a first step towards a multi-functional medical instrument.
Pratisto, Hans S.; Frenz, Martin; Koenz, Flurin; Altermatt, Hans J.; Weber, Heinz P.
1996-05-01
319
E-print Network
Developing of new rare-earth (RE)-doped optical fibres for power amplifiers and lasers requires continuous improvements in the fibre spectroscopic properties (like shape and width of the gain curve, optical quantum efficiency, resistance to spectral hole burning and photodarkening...). Silica glass as a host material for fibres has proved to be very attractive. However, some potential applications of RE-doped fibres suffer from limitations in terms of spectroscopic properties resulting from clustering or inappropriate local environment when doped into silica. To this aim, we present a new route to modify some spectroscopic properties of RE ions in silica-based fibres based on the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in-situ in fibre preforms. By adding alkaline earth elements, in low concentration into silica, one can obtain a glass with an immiscibility gap. Then, phase separation occurs under an appropriate heat treatment. We investigated the role of three alkaline-earth...
Blanc, Wilfried; Dussardier, Bernard; 10.1504/IJNT.2012.045350
2012-01-01
320
Ultracold dipolar gases offer a promising playground for exploring a wide variety of novel quantum phases as well as quantum magnetism. Recent advances in laser cooling technique have opened up a possibility to reach ultracold temperature with highly magnetic rare-earth atoms. Here, we present our results towards Bose-Einstein condensation of Erbium atoms. By using a broad transition at 401 nm for Zeeman slowing and a narrow transition at 583 nm for a magneto-optical trap (MOT), we obtained up to 3x10^8 atoms at a temperature of 15 ?K. Typically 1x10^7 atoms are directly loaded from a MOT into an optical dipole trap operating at 1064 nm. The results show that our approach gives a good starting condition for evaporative cooling.
Aikawa, Kiyotaka; Frisch, Albert; Mark, Michael; Rietzler, Alexander; Schindler, Johannes; Zupanic, Erik; Baier, Simon; Grimm, Rudolf; Ferlaino, Francesca
2012-06-01
321
SciTech Connect
Two different regimes of Q-switching in the same implementation of an actively Q-switched erbium-doped fiber laser are demonstrated. Depending on the active fiber length and repetition rate of an intracavity Q-cell (acousto-optic modulator), the laser operates either in the regime of common, rather long and low-power, pulses composed of several sub-pulses or in the one of very short and powerful stimulated Brillouin scattering-induced pulses. The basic physical reason of the laser system to oscillate in one of these two regimes is the existence or absence of CW narrow-line “bad-cavity” lasing in the intervals when the Q-cell is blocked.
Barmenkov, Yuri O., E-mail: [email protected]; Kir'yanov, Alexander V. [Centro de Investigaciones en Optica, Loma del Bosque 115, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Cruz, Jose L.; Andres, Miguel V. [Department of Applied Physics and Electromagnetism, University of Valencia, Dr. Moliner 50, Burjassot 46100 (Spain)
2014-03-03
322
Because of the high absorption of near-infrared laser radiation in biological tissue, erbium lasers and holmium lasers emitting at 3 and 2 mu m, respectively, have been proven to have optimal qualities for cutting or welding and coagulating tissue. To combine the advantages of both wavelengths, we realized a multiwavelength laser system by simultaneously guiding erbium and holmium laser radiation by means of a single zirconium fluoride (ZrF4) fiber. Laser-induced channel formation in water and poly(acrylamide) gel was investigated by the use of a time-resolved flash-photography setup, while pressure transients were recorded simultaneously with a needle hydrophone. The shapes and depths of vapor channels produced in water and in a submerged gel after single erbium and after combination erbium-holmium radiation delivered by means of a 400- mu m ZrF4 fiber were measured. Transmission measurements were performed to determine the amount of pulse energy available for tissue ablation. The effects of laser wavelength and the delay time between pulses of different wavelengths on the photomechanical and photothermal responses of meniscal tissue were evaluated in vitro by the use of histology. It was observed that the use of a short (200- mu s, 100-mJ) holmium laser pulse as a prepulse to generate a vapor bubble through which the ablating erbium laser pulse can be transmitted (delay time, 100 mu s) increases the cutting depth in meniscus from 450 to 1120 mu m as compared with the depth following a single erbium pulse. The results indicate that a combination of erbium and holmium laser radiation precisely and efficiently cuts tissue under water with 20-50- mu m collateral tissue damage. wave, cavitation, channel formation, infrared-fiber-delivery system, tissue damage, cartilage.
Pratisto, Hans; Frenz, Martin; Ith, Michael; Altermatt, Hans J.; Jansen, E. Duco; Weber, Heinz P.
1996-07-01
323
E-print Network
Passive mode locking in erbium fiber lasers with negative group delay M. E. Fermann, M. J. Andrejco are generated in passively mode-locked erbium fiber lasers with small negative group-velocity dispersion- theless, the potential pulse-width limit of 60 fs set by the erbium gain bandwidth6 has not yet been
Purdue University
324
E-print Network
Measurements of the intensity noise of a broadly tunable, erbium-do fiber ring laser, relative February 1992; accepted for publication 16 March 1992) The intensity noise of an erbium-doped fiber ring-Perot erbium-doped fiber laser has recently emerged as a potential candidate for communication systems
Park, Namkyoo
325
E-print Network
Erbium-implanted high-Q silica toroidal microcavity laser on a silicon chip Bumki Min, Tobias J; published 16 September 2004) Lasing from an erbium-doped high-Q silica toroidal microcavity coupled to a tapered optical fiber is dem- onstrated and analyzed. Average erbium ion concentrations were in the range
Polman, Albert
326
E-print Network
Co-lasing in an electrically tunable erbium-doped fiber laser Jay W. Dawson, Namkyoo Park simultaneous wavelength operation (co-lasing) of an erbium-doped fiber ring laser with independent tunability tunable single-frequency, erbium-doped fiber ring laser with a tandem Fabry-Perot filter,le3 having
Park, Namkyoo
327
E-print Network
Reduction of the intensity noise from an erbium-doped fiber laser to the standard quantum limit Fabry-Perot erbium-doped fiber ring laser is reduced to the standard quantum limit, with a 0.5 d modes using a narrow-band fiber Fabry-Perot etalon. Broadly tunable, single-frequency erbium-doped fiber
Park, Namkyoo
328
E-print Network
SEM-mapped micro-photoluminescence studies of highly luminescent micro-clusters in erbium Available online 8 September 2010 Keywords: Erbium Stark Micro-clusters Photoluminescence ErSRSO SEM a b s t r a c t This paper reports on the formation of unique micrometer-scale clusters in erbium
329
E-print Network
Abstract--We demonstrate adaptive control of mode- dependent gain in a multi-mode erbium far been proposed for controlling MDG in multi-mode erbium-doped fiber amplifiers (MM-EDFAs). One approach would be to use an optimized erbium doping profile in the MM-EDFA [5]. While this approach can
Kahn, Joseph M.
330
E-print Network
Using Erbium-Doped Fiber Laser Incorporating an Electroabsorption Modulator and a Linear Optical using an erbium-doped fiber laser that incorporates an electroabsorption modulator and a linear optical, and erbium-doped fiber (EDF) laser, or semiconductor-optical- amplifier-based fiber mode-locked lasers
Wai, Ping-kong Alexander
331
E-print Network
40 GHz actively mode-locked erbium-doped fiber ring laser using an electro-absorption modulator, Hong Kong Abstract: We demonstrated a 40-GHz actively mode-locked erbium-doped fiber laser mode-locking the laser. Q-switching occurs easily in erbium-doped fiber lasers incorporating
Wai, Ping-kong Alexander
332
E-print Network
10 GHz actively mode-locked erbium-doped fiber ring laser using an electro-absorption modulator, Hung Hom, Hong Kong Abstract: We demonstrated a 10-GHz actively mode-locked erbium-doped fiber laser-bit-rate clock recovery or demultiplexing [1]. Reported mode-locking techniques include erbium-doped fiber lasers
Wai, Ping-kong Alexander
333
E-print Network
June 1, 1993 / Vol. 18, No. 11 / OPTICS LETTERS 879 Frequency locking of an erbium-doped fiber ring 91125 Received December 23, 1992 An all-fiber, single-frequency, erbium-doped ring laser has been lifetime.3'4 We have recently demonstrated an all-fiber erbium- doped ring laser whose characteristics
Park, Namkyoo
334
E-print Network
Reducing pulse distortion in fast-light pulse propagation through an erbium-doped fiber amplifier.65.Ã?k Keywords: Fast-light propagation Pulse distortion reduction Erbium-doped fiber a b s t r a c in fast-light propagation through an erbium-doped fiber amplifier by placing the pulse on top
Boyd, Robert W.
335
E-print Network
in Fermionic Erbium-167 Albert Frisch, Kiyotaka Aikawa, Michael Mark, and Francesca Ferlaino Institut f structure of the only stable fermionic isotope of atomic erbium as well as determined its isotope shift of the hyperfine structure of the only stable fermionic erbium isotope, 167 Er. In particular, we obtain
Kotochigova, Svetlana
336
PubMed
An ultrathin Ni interlayer (?1 nm) was introduced between a TaN-capped Er film and a Si substrate to prevent the formation of surface defects during thermal Er silicidation. A nickel silicide interfacial layer formed at low temperatures and incurred uniform nucleation and the growth of a subsequently formed erbium silicide film, effectively inhibiting the generation of recessed-type surface defects and improving the surface roughness. As a side effect, the complete transformation of Er to erbium silicide was somewhat delayed, and the electrical contact property at low annealing temperatures was dominated by the nickel silicide phase with a high Schottky barrier height. After high-temperature annealing, the early-formed interfacial layer interacted with the growing erbium silicide, presumably forming an erbium silicide-rich Er-Si-Ni mixture. As a result, the electrical contact property reverted to that of the low-resistive erbium silicide/Si contact case, which warrants a promising source/drain contact application for future high-performance metal-oxide-semiconductor field-effect transistors. PMID:25093916
Choi, Juyun; Choi, Seongheum; Kang, Yu-Seon; Na, Sekwon; Lee, Hoo-Jeong; Cho, Mann-Ho; Kim, Hyoungsub
2014-08-27
337
PubMed
A single-frequency Er-doped fiber laser that is tunable from 1.52 to 1.58 ,microm has been constructed. The laser linewidth was determined to be less than 1.6 MHz FWHM by observing the spectrum of the beat between the fiber laser and a 1.523-microm He-Ne laser. The frequency of the fiber laser was locked to several absorption lines of acetylene near 1.53 microm. This research demonstrates the inherent stability of fiber lasers and their potential for use in a wavelength standard for optical communications. PMID:19773865
Gilbert, S L
1991-02-01
338
A real time multichannel dynamic erbium doped fiber amplifier (EDFA) Simulink model with flat gain and gain clamping facility has been developed on a MATLAB platform. We model the EDFA simulator with one-dimensional nonlinear differential equation that describes the time dependent population density. For the model to show gain flattening multiplexed channels at different wavelengths, the MATLAB function block is used. Next, to simulate the noise performance of EDFA. New forward amplified spontaneous emission (ASE) noise blocks are designed that add noise dynamically at signal wavelength. The model has been implemented in the study of performance characteristics of an EDFA in both C- and L-band signal amplification by simulation. Based on the designed ASE generator, noise figure for different signal wavelengths are calculated. For 980 nm pump power, the noise figure almost reaches the practical limit of 3 dB whereas for 1480 nm pump power, a variation of about 1.5 dB and 0.8 dB is observed from the practical limit for the C- and L-bands, respectively. The present model can be implemented successfully as a test bed in the study of EDFA gain dynamics over the entire third optical communication bandwidth (1525 to 1690 nm) in signal amplification.
Roy, Sharbani; Priye, Vishnu; Kumar, Santosh
2013-04-01
339
With new fiber systems available for 3 ?m, Erbium lasers become more interesting for precise tissue ablation in a water environment enabling new application in e.g. dentistry. The dynamics of explosive bubble formation was investigated at 2.78 ?m (Er,Cr;YSGG) and 2.94 ?m (Er:YAG), in relation to energy (10-50 mJ), pulse length (20-150 ?s) and fiber tip shape (flat or taper). The dynamics of exploding and imploding vapor bubbles were captured with high speed imaging (10 - 300 ?s range). Increasing the pulse length and energy, the vapor bubble became more elongated with an opaque surface for flat tip fibers. Tapered fibers produced spherical vapor bubbles with an optically transparent surface expected to be more forceful for creating mechanical effects in both hard and soft tissues. There was no significant difference between bubbles formed at 2.78 ?m (Er,Cr;YSGG) and 2.94 ?m (Er:YAG).
Verleng, Marja; Verdaasdonk, Rudolf; van der Veen, Albert; Lemberg, Vladimir; Boutoussov, Dmitri
2014-02-01
340
GaN is an excellent host for erbium (Er) to provide optical emission in the technologically important as well as eye-safe 1540 nm wavelength window. Er doped GaN (GaN:Er) epilayers were synthesized on c-plane sapphire substrates using metal organic chemical vapor deposition. By employing a pulsed growth scheme, the crystalline quality of GaN:Er epilayers was significantly improved over those obtained by conventional growth method of continuous flow of reaction precursors. X-ray diffraction rocking curve linewidths of less than 300 arc sec were achieved for the GaN (0002) diffraction peak, which is comparable to the typical results of undoped high quality GaN epilayers and represents a major improvement over previously reported results for GaN:Er. Spectroscopic ellipsometry was used to determine the refractive index of the GaN:Er epilayers in the 1540 nm wavelength window and a linear dependence on Er concentration was found. The observed refractive index increase with Er incorporation and the improved crystalline quality of the GaN:Er epilayers indicate that low loss GaN:Er optical waveguiding structures are feasible.
Alajlouni, S.; Sun, Z. Y.; Li, J.; Zavada, J. M.; Lin, J. Y.; Jiang, H. X.
2014-08-01
341
Diffusion of interstitial atomic hydrogen in erbium oxide (Er2O3) was investigated using density functional theory (DFT) and molecular dynamics (MD) methods. Hydrogen diffusivity in bulk, on (0 0 1) surface, and along ?13 (4-3-1)/[1 1 1] symmetric tilt grain boundaries (GBs) were evaluated in a temperature range of 673-1073 K, as well as hydrogen diffusion barriers. It was found that H diffusion shows the faster on (0 0 1) surface than along GBs and in bulk. Also, energy barrier of H diffusion in bulk estimated by DFT and MD methods is somewhat higher than that along GBs evaluated in the experiments. This suggests that H diffusion in Er2O3 coatings depends on GBs rather than bulk. In addition, with a correction of GB density, the simulated diffusivity along GBs in MD simulations is in good agreement with the experimental data within one order of magnitude. The discrepancy of H diffusivity between the experiments and the simulations should be reduced by considering H concentration, H diffusion direction, deviations of the initial configuration, vacancy defects, etc.
Mao, Wei; Chikada, Takumi; Suzuki, Akihiro; Terai, Takayuki
2014-12-01
342
PubMed
The purpose of the study was to evaluate the effect of erbium (Er): yttrium aluminum garnet (YAG) laser trabecular ablation with a sapphire optical fiber on outflow facility. After obtaining baseline outflow facility using a computerized differential pressure perfusion system, human cadaver eyes were subjected to Er: YAG laser trabecular ablation using a sapphire optical fiber. Single pulses at varying energy levels (10 to 20 mJ pulse-1) were applied in a nearly contiguous fashion over four clock hours of meshwork. Post-laser outflow facility was then determined utilizing the same perfusion system and histopathologic analysis performed. Of the ten eyes, nine were perfused to steady baseline facility. One eye was excluded from the study because of a leak in our system during the initial perfusion. The mean baseline facility was 0.283+/-0.08 microl min-1 mmHg-1. There was a significant increase in outflow facility after trabecular ablation, with a mean post-laser facility of 0.62+/-0.15 microl min-1 mmHg-1 (P=0.01). Eyes which received a sham treatment showed no increase or a minimal increase in facility. Histopathologic analysis revealed ablation into Schlemm's canal with some thermal damage to the outer wall at all energy levels. Er: YAG laser trabecular ablation with a sapphire fiber is capable of increasing outflow facility in human cadaver eyes. PMID:9268583
McHam, M L; Eisenberg, D L; Schuman, J S; Wang, N
1997-08-01
343
PubMed
Epilayers of erbium-doped GaN (GaN:Er) were synthesized by metal-organic chemical vapor deposition, and the optical excitation cross section (?(exc)) of Er ions in this host material were determined. Photoluminescence (PL) measurements were made using laser diodes at excitation wavelengths of 375 and 405 nm, and the integrated emission intensity at 1.54 ?m was measured as a function of excitation photon flux. Together with time-resolved PL measurements, values of ?(exc) of Er ions in GaN:Er were obtained. For excitation at 375 nm, the observed excitation cross section was found to be 4.6×10(-17) cm(-2), which is approximately three orders of magnitude larger than that using resonant excitation. Based on the present and previous works, the optical excitation cross section ?(exc) of Er ions in GaN:Er as a function the excitation wavelength has been obtained. The large values of ?(exc) with near-band-edge excitation makes GaN:Er attractive for realization of chip-scale photonic devices for optical communications. PMID:23434981
Feng, I-Wen; Li, Jing; Lin, Jingyu; Jiang, Hongxing; Zavada, John
2013-02-20
344
The lasing characteristics of an erbium-doped fiber laser with a nonlinear amplifying loop mirror (NALM) were investigated in detail. The NALM was pumped by 1.48 ?m InGaAsP laser diodes and an output pulse as short as 124 fs was obtained at 1.56 ?m. The 124-fs pulse was shortened to 50 fs by using adiabatic soliton narrowing and high order soliton compression. Soliton narrowing was achieved by amplifying the soliton pulse adiabatically with an erbium-doped fiber amplifier, and a short length of dispersion-flattened fiber was used for soliton compression. Soliton narrowing enabled us to succeed in generating a 98-fs pulse directly from a modified erbium-doped fiber laser.
Yoshida, Eiji; Kimura, Yasuo; Nakazawa, Masataka
1993-08-01
345
The lasing characteristics of an erbium-doped fiber laser with a nonlinear amplifying loop mirror (NALM) were investigated in detail. The NALM was pumped by 1.48 micron InGaAsP laser diodes and an output pulse as short as 123 fs was obtained at 1.56 micron. The 124-fs pulse was shortened to 50 fs by using adiabatic soliton narrowing and high order soliton compression. Soliton narrowing was achieved by amplifying the soliton pulse adiabatically with an erbium-doped fiber amplifier, and a short length of dispersion-flattened fiber was used for soliton compression. Soliton narrowing enabled us to succeed in generating a 98-fs pulse directly from a modified erbium-doped fiber laser.
Yoshida, Eiji; Kimura, Yasuo; Nakazawa, Masataka
1993-08-01
346
Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol–gel method are presented in this article. Strong photoluminescence at 1.54 ?m, important for fiber optics telecommunication systems, is observed from the different sol–gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er3+ ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established.
Manna, S.; Aluguri, R.; Bar, R.; Das, S.; Prtljaga, N.; Pavesi, L.; Ray, S. K.
2015-01-01
347
PubMed
Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol-gel method are presented in this article. Strong photoluminescence at 1.54 ?m, important for fiber optics telecommunication systems, is observed from the different sol-gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er(3+) ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established. PMID:25558802
Manna, S; Aluguri, R; Bar, R; Das, S; Prtljaga, N; Pavesi, L; Ray, S K
2015-01-30
348
SciTech Connect
The study is concerned with the luminescence properties of ensembles of semiconductor structures containing organic phthalocyanine molecules with erbium ions as complexing agents. The photoluminescence spectra of the structures of the type of erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine are recorded. The photoluminescence peaks are detected at the wavelengths 888, 760, and 708 nm (and photon energies 1.4, 1.6, and 1.75 eV) corresponding to electronic transitions within the organic complexes. It is found that, when a metal complexing agent is introduced into the molecular structure of the ligand, the 708 nm luminescence peak becomes unobservable. It is shown that, in the bisphthalocyanine samples, the photoluminescence signal corresponding to transitions from the 4F{sub 9/2} level of erbium ions is enhanced.
Belogorokhov, I. A., E-mail: [email protected]; Ryabchikov, Yu. V.; Tikhonov, E. V.; Pushkarev, V. E.; Breusova, M. O.; Tomilova, L. G.; Khokhlov, D. R. [Moscow State University (Russian Federation)
2008-03-15
349
E-print Network
This work reports optical functionality contained in, as well as and produced by, thin film coatings. A sol-gel process, formulated with precursor active ingredients of erbium oxide and tetraethylorthosilicate (TEOS), was used for spin-coating thin (~130 nm) erbium-doped (~6 at. %) silica films on single-crystal silicon. Annealed films produce infrared emission in the 1.5-micron band from erbium ions in the film, as well as greatly enhancing (~100X) band-gap emission from the underlying silicon. The distinctly different mechanisms for the two modes of optical activities are interpreted in terms of optical emission theory and modeling; prospects for opto-electronic applications are discussed.
Abedrabbo, Sufian; Shet, Sudhakar; Fiory, Anthony; Ravindra, Nuggehalli
2012-01-01
350
We have fabricated erbium-doped amorphous silicon p-i-n structures by conventional plasma decomposition of silane. The erbium doping was achieved by sublimation of the metal-organic compound tris(2,4-pentanedionato)-Er(III) which has a more favorable erbium-carbon ratio than previously used compounds. Since the Er centers introduce donors and defects in the amorphous silicon, counterdoping with diborane has been required to obtain the near-intrinsic i layers with a reduced defect density. The p-i-n junctions have excellent diode characteristics and exhibit, under forward bias, pronounced electroluminescence near 1.54 m at room temperature. Their power efficiency is by two orders of magnitude larger than that of previously fabricated heterojunctions of amorphous and crystalline silicon. We discuss possible mechanisms of the Er3+ excitation in our diodes.
Mell, H.; Weiser, G.; Terukov, E. I.; Kudoyarova, V. Kh.
2004-03-01
351
PubMed
We demonstrate a fast-tuning Brillouin/erbium fiber laser (BEFL) using 4 m erbium-doped fiber (EDF) as both the Brillouin and erbium gain media. The BEFL frequency is fast tuned via modulating a piezoelectric transducer on which the EDF is coiled. Over 60 MHz frequency-tuning range is obtained at less than 5 V voltage amplitude and the tuning rates can achieve 48 kHz. This fast-tuning BEFL presents a low phase noise of -124 dB/Hz(1/2) at 1 kHz (normalized to 1 m interferometer optical path difference) with 32 kHz modulating frequency. It presents potential applications in fiber sensors and optical communications. PMID:24487900
Chen, Mo; Meng, Zhou; Tu, Xiaobo; Zhang, Yichi
2014-02-01
352
The experimental setup of this study is focused on the changes in temporomandibular joint tissue after irradiation with an Erbium:YAG laser. Initially, the free-running beam from the laser was focused onto freshly excised porcine tissue samples, indicating an optimum average energy density and pulse duration for the purpose of temporomandibular joint surgery of about 15 - 60 J/cm2 and 120 microsecond(s) - 240 microsecond(s) , respectively. Consecutively, an attempt was made to couple the Erbium:YAG laser beam on the one hand to optical fibers made of infrared-transmitting glasses (fluoride- and chalcogenide-based), on the other hand to a recently developed sapphire and liquid core fiber, respectively. From the preliminary observations of this investigation it appears that both the liquid core and the sapphire fiber are the most promising candidates for delivery of Erbium-YAG laser radiation in arthroscopic surgery of the craniomandibular articulation.
Nuebler-Moritz, Michael; Hering, Peter; Niederdellmann, Herbert; Deuerling, Christian; Dammer, Ralf
1995-05-01
353
SciTech Connect
Dislocation-related photoluminescence at 0.806 and 0.873 eV is observed in erbium-doped silicon epi layers grown by liquid-phase epitaxy on (100) Si wafers. These signals are detected at T = 2 K only on epi layers deposited on Czochralski grown silicon substrates. No luminescence is observed when float zone-grown substrates are used. The peak intensity shows temperature quenching, but the signal remains detectable up to 195 K. The luminescence apparently is due to dislocations in silicon in the simultaneous presence of high oxygen concentration and erbium impurities. A comparison with the typical infrared emission from erbium-implanted silicon samples is presented.
Pizzini, S.; Donghi, M.; Binetti, S.; Wagner, G.; Bersani, M. [Univ. Degli Studi di Milano, Milan (Italy)
1998-01-01
354
SciTech Connect
Photoluminescence spectra of n-type silicon upon implantation with erbium ions at 600 Degree-Sign C and oxygen ions at room temperature and subsequent annealings at 1100 Degree-Sign C in a chlorine-containing atmosphere have been studied. Depending on the annealing duration, photoluminescence spectra at 80 K are dominated by lines of the Er{sup 3+} ion or dislocation-related luminescence. The short-wavelength shift of the dislocation-related luminescence line observed at this temperature is due to implantation of erbium ions at an elevated temperature. At room temperature, lines of erbium and dislocation-related luminescence are observed in the spectra, but lines of near-band-edge luminescence predominate.
Sobolev, N. A., E-mail: [email protected]; Kalyadin, A. E.; Shek, E. I.; Sakharov, V. I.; Serenkov, I. T. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Vdovin, V. I. [St. Petersburg University, Fock Research Institute of Physics (Russian Federation); Parshin, E. O.; Makoviichuk, M. I. [Russian Academy of Sciences, Yaroslavl Branch, Institute of Physics and Technology (Russian Federation)
2011-08-15
355
A continuous wave suppressed, uniformly repetitive pulse train as short as 136-145 fs has been successfully generated at a wavelength of 1.55 micron from a new type of femtosecond erbium-doped fiber laser with nonlinear polarization rotation. The 145 fs pulse was shortened to 52 fs by using soliton narrowing and high order soliton compression. Soliton narrowing was achieved by amplifying the soliton pulse with an erbium-doped fiber amplifier, and a short length of dispersion-flattened fiber was used for further compressing the soliton.
Yoshida, Eiji; Kimura, Yasuo; Nakazawa, Masataka
1994-10-01
356
A continuous wave suppressed, uniformly repetitive pulse train as short as 136 145 fs has been successfully generated at a wavelength of 1.55 µ m from a new type of femtosecond erbium-doped fiber laser with nonlinear polarization rotation. The 145 fs pulse was shortened to 52 fs by using soliton narrowing and high order soliton compression. Soliton narrowing was achieved by amplifying the soliton pulse with an erbium-doped fiber amplifier, and a short length of dispersion-flattened fiber was used for further compressing the soliton.
Yoshida, Eiji; Kimura, Yasuo; Nakazawa, Masataka
1994-10-01
357
We have studied the effect of up-conversion by residual erbium ions, observed in a KGW crystal in the green and red regions of the spectrum upon excitation by the radiation output from diode lasers with wavelengths 808 nm and 970 nm. We demonstrate the existence of different up-conversion regimes under conditions where there is a residual erbium ion concentration. The experimental data indicate up-conversion processes for excitation by laser radiation with wavelength 970 nm with n > 2, where n is a parameter characterizing the dependence of the luminescence intensity on pump power.
Khodasevich, I. A.; Kornienko, A. A.; Dunina, E. B.; Grabtchikov, A. S.
2015-01-01
358
In this paper, the chaotic behaviors in an erbium-doped fiber (EDF) single-ring laser (EDFSRL) are investigated experimentally by using the loss modulation method. An electro—optic modulator (EOM) made of LiNbO3 crystal is added to the system. Thus, by changing the modulation voltage and the modulation frequency of the EOM, the freedom of the EDFSRL system is increased. The chaotic characteristics of the system are studied by observing the time series and the power spectra. The experimental results indicate that the erbium-doped fiber single-ring laser system can enter into chaos states through period-doubling bifurcation and intermittency routes.
Chang, Feng; Feng, Yu-Ling; Yao, Zhi-Hai; Fan, Jian; Song, Yuan-Chao; Zhao, Yu-Zhu
2012-10-01
359
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
152. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Transit Book #363, Page 1). 1912 CONDITION REPORT OF MILNER DAM AREA, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID
360
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
152. View of lightning arrester houses on the hillside above powerhouse. To the right is surge tank for penstock no. 1. Looking southeast. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA
361
Code of Federal Regulations, 2013 CFR
...FOR HUMAN CONSUMPTION FRUIT PIES Requirements for Specific Standardized Fruit Pies § 152.126 Frozen...and Cosmetic Act or color additives as defined...are food additives or color additives as so defined...follows: (i) The fruit content of the pie...
2013-04-01
362
Code of Federal Regulations, 2011 CFR
...FOR HUMAN CONSUMPTION FRUIT PIES Requirements for Specific Standardized Fruit Pies § 152.126 Frozen...and Cosmetic Act or color additives as defined...are food additives or color additives as so defined...follows: (i) The fruit content of the pie...
2011-04-01
363
Code of Federal Regulations, 2012 CFR
...FOR HUMAN CONSUMPTION FRUIT PIES Requirements for Specific Standardized Fruit Pies § 152.126 Frozen...and Cosmetic Act or color additives as defined...are food additives or color additives as so defined...follows: (i) The fruit content of the pie...
2012-04-01
364
...FOR HUMAN CONSUMPTION FRUIT PIES Requirements for Specific Standardized Fruit Pies § 152.126 Frozen...and Cosmetic Act or color additives as defined...are food additives or color additives as so defined...follows: (i) The fruit content of the pie...
2014-04-01
365
Code of Federal Regulations, 2010 CFR
...2010-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...
2010-10-01
366
Code of Federal Regulations, 2011 CFR
...2011-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...
2011-10-01
367
...2014-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...
2014-10-01
368
Code of Federal Regulations, 2013 CFR
...2013-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...
2013-10-01
369
Code of Federal Regulations, 2012 CFR
...2012-10-01 false Transition to the exchanges...REQUIREMENTS RELATING TO HEALTH CARE ACCESS PRE-EXISTING...INSURANCE PLAN PROGRAM Transition to Exchanges § 152...develop procedures to transition PCIP enrollees to...1321 of the Affordable Care Act, to ensure...
2012-10-01
370
...2014-01-01 2014-01-01 false Simple risk weight approach (SRWA). 3.152 ...TREASURY CAPITAL ADEQUACY STANDARDS Risk-Weighted Assets-Internal Ratings-Based and Advanced Measurement Approaches Risk-Weighted Assets for Equity Exposures...
2014-01-01
371
...2014-01-01 2014-01-01 false Simple risk weight approach (SRWA). 324.152...ADEQUACY OF FDIC-SUPERVISED INSTITUTIONS Risk-Weighted Assets-Internal Ratings-Based and Advanced Measurement Approaches Risk-Weighted Assets for Equity Exposures...
2014-01-01
372
...2014-01-01 2014-01-01 false Simple risk weight approach (SRWA). 217.152...ADEQUACY OF BOARD-REGULATED INSTITUTIONS Risk-Weighted Assets-Internal Ratings-Based and Advanced Measurement Approaches Risk-Weighted Assets for Equity Exposures...
2014-01-01
373
We report thermal diffusivity and ultrasonic sound velocity data for both phases of saturated diflourethane (R152a) in the temperature range from 278 K to the critical temperature. The data were obtained in thermodynamic equilibrium by applying dynamic light scattering. For both values comparison with data from literature has been made.
Kraft, K.; Leipertz, A.
1994-09-01
374
We report thermal diffusivity and ultrasonic sound velocity data for both phases of saturated diflourethane (R152a) in the temperature range from 278 K to the critical temperature. The data were obtained in thermodynamic equilibrium by applying dynamic light scattering. For both values comparison with data from literature has been made.
K. Kraft; A. Leipertz
1994-01-01
375
SciTech Connect
Based on reliable, carefully selected data sets, equations for the thermal conductivity and the viscosity of the refrigerant R152a are presented. They are valid at temperatures from 240 to 440 K, pressures up to 20 MPa, and densities up to 1050 kg {center_dot} m {sup {minus}3}, including the critical region.
Krauss, R.; Stephan, K. [Institut fuer Technische Thermodynamik und Thermische Verfahrenstechnik, Stuttgart (Germany); Weiss, V.C.; Edison, T.A.; Sengers, J.V. [Univ. of Maryland, College Park, MD (United States)
1996-07-01
376
The samarium isotopic chain shows great structural change dripline-to-dripline; evolving from deformed at the proton dripline, through spherical near stability before undergoing another transformation near N=90 when large prolate deformation re-emerges. Lying at the midpoint of this latter transition is ^152Sm. Numerous models have been developed to explain ^152Sm in terms of either being at the critical point of a phase transition, or in terms of coexisting shapes. To test the validity of these different models, a beta-decay experiment was performed at the ATLAS facility at Argonne. The decay of ^152Eu to ^152Sm was studied through gamma-ray spectroscopy using Gammasphere. An extremely large data set was collected, consisting of > 7x10^9 gamma-gamma or higher fold events. This made possible a high precision measurement of energies and intensities and very definite angular correlation determinations. The new results resolve some previous experimental ambiguities and help to differentiate between theoretical models. Work supported by the DOE Office of Nuclear Physics under contract DE-AC02-06CH11357.
McCutchan, E. A.; Lister, C. J.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Seweryniak, D.
2010-11-01
377
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
35. INTERIOR VIEW TO THE NORTHWEST OF ROOM 152, A FIRST FLOOR CORRIDOR AND VIEWING GALLERY ON THE WEST SIDE OF THE POST-MORTEM CELLS. VIEWING AND WORK STATIONS ARE IN THE EAST WALL. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
378
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
152. Photographic copy of original construction drawing dated October 24, 1930 (from Record Group 115, Denver Branch of the National Archives, Denver). 60 x 12 RING GATE CONTROL; FLOAT WELL ASSEMBLY AND COVER HOIST STEM-CONNECTION ROD-SLEEVE. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR
379
Code of Federal Regulations, 2010 CFR
...Conveyances of Trust Or Restricted Lands § 152.31 Cost of conveyance; payment. Pursuant to the Act of February 14, 1920 (41 Stat. 415), as amended by the Act of March 1, 1933 (47 Stat. 1417; 25 U.S.C. 413), the Secretary...
2010-04-01
380
Code of Federal Regulations, 2011 CFR
...Application for orders removing restrictions, except Five Civilized Tribes. 152.10 Section 152.10 Indians BUREAU...Application for orders removing restrictions, except Five Civilized Tribes. Any Indian not under legal disability under...
2011-04-01
381
Code of Federal Regulations, 2010 CFR
...Application for orders removing restrictions, except Five Civilized Tribes. 152.10 Section 152.10 Indians BUREAU...Application for orders removing restrictions, except Five Civilized Tribes. Any Indian not under legal disability under...
2010-04-01
382
Code of Federal Regulations, 2012 CFR
...Application for orders removing restrictions, except Five Civilized Tribes. 152.10 Section 152.10 Indians BUREAU...Application for orders removing restrictions, except Five Civilized Tribes. Any Indian not under legal disability under...
2012-04-01
383
Code of Federal Regulations, 2013 CFR
...Application for orders removing restrictions, except Five Civilized Tribes. 152.10 Section 152.10 Indians BUREAU...Application for orders removing restrictions, except Five Civilized Tribes. Any Indian not under legal disability under...
2013-04-01
384
...false Issuance of orders removing restrictions, except Five Civilized Tribes. 152.11 Section 152.11 Indians BUREAU...11 Issuance of orders removing restrictions, except Five Civilized Tribes. (a) An application for an order...
2014-04-01
385
Code of Federal Regulations, 2013 CFR
...false Issuance of orders removing restrictions, except Five Civilized Tribes. 152.11 Section 152.11 Indians BUREAU...11 Issuance of orders removing restrictions, except Five Civilized Tribes. (a) An application for an order...
2013-04-01
386
...Application for orders removing restrictions, except Five Civilized Tribes. 152.10 Section 152.10 Indians BUREAU...Application for orders removing restrictions, except Five Civilized Tribes. Any Indian not under legal disability under...
2014-04-01
387
Code of Federal Regulations, 2010 CFR
...false Issuance of orders removing restrictions, except Five Civilized Tribes. 152.11 Section 152.11 Indians BUREAU...11 Issuance of orders removing restrictions, except Five Civilized Tribes. (a) An application for an order...
2010-04-01
388
Code of Federal Regulations, 2012 CFR
...true Issuance of orders removing restrictions, except Five Civilized Tribes. 152.11 Section 152.11 Indians BUREAU...11 Issuance of orders removing restrictions, except Five Civilized Tribes. (a) An application for an order...
2012-04-01
389
Code of Federal Regulations, 2011 CFR
...false Issuance of orders removing restrictions, except Five Civilized Tribes. 152.11 Section 152.11 Indians BUREAU...11 Issuance of orders removing restrictions, except Five Civilized Tribes. (a) An application for an order...
2011-04-01
390
Code of Federal Regulations, 2013 CFR
...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...
2013-01-01
391
Code of Federal Regulations, 2011 CFR
...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...
2011-01-01
392
...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...
2014-01-01
393
Code of Federal Regulations, 2010 CFR
...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...
2010-01-01
394
Code of Federal Regulations, 2012 CFR
...false United States share of project costs. 152.205 Section 152...205 United States share of project costs. (a) Airport development...States share of the allowable project costs of an airport planning project...
2012-01-01
395
Code of Federal Regulations, 2012 CFR
...withdrawing portion of authority conferred by power of attorney. 221.152 Section 221...REGULATIONS TARIFFS Giving and Revoking Powers of Attorney to Agents § 221.152 ...withdrawing portion of authority conferred by power of attorney. If a carrier desires...
2012-01-01
396
Code of Federal Regulations, 2013 CFR
...withdrawing portion of authority conferred by power of attorney. 221.152 Section 221...REGULATIONS TARIFFS Giving and Revoking Powers of Attorney to Agents § 221.152 ...withdrawing portion of authority conferred by power of attorney. If a carrier desires...
2013-01-01
397
Code of Federal Regulations, 2010 CFR
...withdrawing portion of authority conferred by power of attorney. 221.152 Section 221...REGULATIONS TARIFFS Giving and Revoking Powers of Attorney to Agents § 221.152 ...withdrawing portion of authority conferred by power of attorney. If a carrier desires...
2010-01-01
398
Code of Federal Regulations, 2011 CFR
...withdrawing portion of authority conferred by power of attorney. 221.152 Section 221...REGULATIONS TARIFFS Giving and Revoking Powers of Attorney to Agents § 221.152 ...withdrawing portion of authority conferred by power of attorney. If a carrier desires...
2011-01-01
399
...withdrawing portion of authority conferred by power of attorney. 221.152 Section 221...REGULATIONS TARIFFS Giving and Revoking Powers of Attorney to Agents § 221.152 ...withdrawing portion of authority conferred by power of attorney. If a carrier desires...
2014-01-01
400
Code of Federal Regulations, 2013 CFR
... false General scope of specified delivery operations. 780.152 Section 780...General Scope of Agriculture Specified Delivery Operations § 780.152 General scope of specified delivery operations. Employment in...
2013-07-01
401
Code of Federal Regulations, 2012 CFR
... false General scope of specified delivery operations. 780.152 Section 780...General Scope of Agriculture Specified Delivery Operations § 780.152 General scope of specified delivery operations. Employment in...
2012-07-01
402
Code of Federal Regulations, 2011 CFR
... false General scope of specified delivery operations. 780.152 Section 780...General Scope of Agriculture Specified Delivery Operations § 780.152 General scope of specified delivery operations. Employment in...
2011-07-01
403
... false General scope of specified delivery operations. 780.152 Section 780...General Scope of Agriculture Specified Delivery Operations § 780.152 General scope of specified delivery operations. Employment in...
2014-07-01
404
Code of Federal Regulations, 2010 CFR
... false General scope of specified delivery operations. 780.152 Section 780...General Scope of Agriculture Specified Delivery Operations § 780.152 General scope of specified delivery operations. Employment in...
2010-07-01
405
...on the importation and exportation of rough diamonds. 12.152 Section 12.152 Customs Duties...on the importation and exportation of rough diamonds. (a) General. The Clean Diamond Trade Act (Pub. L. 108-19)...
2014-04-01
406
...in the Agency's files pertinent to a specific data requirement. 152.95 Section 152.95 Protection...AND CLASSIFICATION PROCEDURES Satisfaction of Data Requirements and Protection of Data Submitters' Rights § 152.95 Citation...
2014-07-01
407
Code of Federal Regulations, 2011 CFR
...Agency's files pertinent to a specific data requirement. 152.95 Section 152...PROCEDURES Procedures To Ensure Protection of Data Submitters' Rights § 152.95 Citation...Agency's files pertinent to a specific data requirement. An applicant normally...
2011-07-01
408
Code of Federal Regulations, 2012 CFR
...Agency's files pertinent to a specific data requirement. 152.95 Section 152...PROCEDURES Procedures To Ensure Protection of Data Submitters' Rights § 152.95 Citation...Agency's files pertinent to a specific data requirement. An applicant normally...
2012-07-01
409
Code of Federal Regulations, 2013 CFR
...Agency's files pertinent to a specific data requirement. 152.95 Section 152...PROCEDURES Procedures To Ensure Protection of Data Submitters' Rights § 152.95 Citation...Agency's files pertinent to a specific data requirement. An applicant normally...
2013-07-01
410
PubMed
Erbium doped fiber amplifier (EDFA) gain transient dynamics are studied in the context of their application in optically reconfigurable networks. We address the question of how to design the EDFA in order to minimize the gain transients present in the output signals of the EDFA when the system is optically reconfigured such that the total average input power levels and wavelengths are changed. Both experimental measurements and theoretical simulations show that the amplitude transients depend on the length of the erbium doped fiber (EDF) and the erbium concentration. We show how it may be possible to reduce the gain transients by appropriate design of the EDFA. PMID:19498777
Chan, P; Tsang, H
2005-09-19
411
SciTech Connect
We give the spectroscopic evidence of energy transfer to erbium ions provided by SnO{sub 2} nanocrystals in silica. The spectral and time resolved analysis of the nanocluster luminescence resonant with Er{sup 3+} transitions demonstrates that erbium ions take part to energy-transfer mechanisms with an efficiency of about 20%. The spectral features of erbium emission excited by energy transfer allow to ascribe it to Er{sup 3+} sites in ordered environments, nearby crystalline tin-dioxide nanoclusters.
Brovelli, S.; Chiodini, A.; Lauria, A.; Meinardi, F.; Paleari, A. [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, via Cozzi 53, I-20125 Milan (Italy)
2006-02-15
412
Erbium-doped GaAS layers were grown by metalorganic vapor phase epitaxy using two new sources, bis(i-propylcyclopentadienyl)cyclopentadienyl erbium and tris(t-butylcyclopentadienyl) erbium. Controlled Er doping in the range of 10(exp 17) - 10(exp 18)/cu cm was achieved using a relatively low source temperature of 90 C. The doping exhibits a second-order dependence on inlet source partial pressure, similar to behavior obtained with cyclopentadienyl Mg dopant sources. Equivalent amounts of oxygen and Er are present in 'as-grown' films indicating that the majority of Er dopants probably exist as Er-O complexes in the material. Er(+3) luminescence at 1.54 micrometers was measured from the as-grown films, but ion implantation of additional oxygen decreases the emission intensity. Electrical compensation of n-type GaAs layers codoped with Er and Si is directly correlated to the Er concentration is proposed to arise from the deep centers associated with Er which are responsible for a broad emission band near 0.90 micrometers present in the photoluminescence spectra of GaAs:Si, Er films.
Redwing, J. M.; Kuech, T. F.; Gordon, D. C.; Vaartstra, B. A.; Lau, S. S.
1994-08-01
413
NASA Technical Reports Server (NTRS)
Erbium-doped GaAS layers were grown by metalorganic vapor phase epitaxy using two new sources, bis(i-propylcyclopentadienyl)cyclopentadienyl erbium and tris(t-butylcyclopentadienyl) erbium. Controlled Er doping in the range of 10(exp 17) - 10(exp 18)/cu cm was achieved using a relatively low source temperature of 90 C. The doping exhibits a second-order dependence on inlet source partial pressure, similar to behavior obtained with cyclopentadienyl Mg dopant sources. Equivalent amounts of oxygen and Er are present in 'as-grown' films indicating that the majority of Er dopants probably exist as Er-O complexes in the material. Er(+3) luminescence at 1.54 micrometers was measured from the as-grown films, but ion implantation of additional oxygen decreases the emission intensity. Electrical compensation of n-type GaAs layers codoped with Er and Si is directly correlated to the Er concentration is proposed to arise from the deep centers associated with Er which are responsible for a broad emission band near 0.90 micrometers present in the photoluminescence spectra of GaAs:Si, Er films.
Redwing, J. M.; Kuech, T. F.; Gordon, D. C.; Vaartstra, B. A.; Lau, S. S.
1994-01-01
414
...2014-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...
2014-07-01
415
Code of Federal Regulations, 2013 CFR
...2013-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...
2013-07-01
416
Code of Federal Regulations, 2010 CFR
...2010-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...
2010-07-01
417
Code of Federal Regulations, 2012 CFR
...2012-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...
2012-07-01
418
Code of Federal Regulations, 2011 CFR
...2011-07-01 false C.I. Disperse Red 152 (generic). 721.2580 Section...Substances § 721.2580 C.I. Disperse Red 152 (generic). (a) Chemical substance...identified generically as C.I. disperse red 152 (PMN P-97-820) is subject...
2011-07-01
419
We propose a coupled system of the Hirota equation and the Maxwell-Bloch equations to describe the wave propagation in an erbium doped nonlinear fiber with higher order dispersion. The Painlevé property of the same is analyzed and the coupled system is found to be integrable. The Lax pair is also constructed and the single-soliton solution is explicitly shown. The coupled
K. Porsezian; K. Nakkeeran
1995-01-01
420
E-print Network
Selectively erbium (Er) doped titanium (Ti) in-diffused optical waveguide amplifiers on lithium niobate (LiNbO3) substrate have been fabricated and characterized in the wavelength regime around ? = 1.53?m using counter-directional pumping at ?P = 1...
Suh, Jae Woo
2011-02-22
421
PubMed
In this Letter, we present a comprehensive comparison of the performance of a zirconia-based erbium-doped fiber amplifier (Zr-EDFA) and a bismuth-based erbium-doped fiber amplifier (Bi-EDFA). The experimental results reveal that a Zr-EDFA can achieve comparable performance to the conventional Bi-EDFA for C-band and L-band operations. With a combination of both Zr and Al, we could achieve a high erbium-doping concentration of about 2800 ppm (parts per million) in the glass host without any phase separations of rare earths. The Zr-based erbium-doped fiber (Zr-EDF) was fabricated using in a ternary glass host, zirconia-yttria-aluminum codoped silica fiber through a solution-doping technique along with modified chemical vapor deposition. At a high input signal of 0 dBm, a flat gain at average value of 13 dB is obtained with a gain variation of less than 2 dB within the wavelength region of 1530-1575 nm and using 2 m of Zr-EDF and 120 mW pump power. The noise figures are less than 9.2 at this wavelength region. It was found that a Zr-EDFA can achieve even better flat-gain value and bandwidth as well as lower noise figure than the conventional Bi-EDFA. PMID:20808356
Paul, M C; Harun, S W; Huri, N A D; Hamzah, A; Das, S; Pal, M; Bhadra, S K; Ahmad, H; Yoo, S; Kalita, M P; Boyland, A J; Sahu, J K
2010-09-01
422
Objective. A study is made of the efficacy of the Erbium:YAG laser in granulomatous periapical lesions, based on clinical and radiographic controls. Material and methods. The study comprised a series of 45 patients amenable to periapical surgical treatment of incisors, canines and premolars. A conventional surgical technique was used, with silver amalgam retrograde filling and irradiation of the bone defect
María Isabel; Leco Berrocal; José María Martínez González; Manuel Donado Rodríguez
423
The nonlinear optical loop mirror (NOLM) is used as a saturable absorbed to reshape pulses. Experimentally, an actively mode-locked erbium-doped fiber ring laser with figure-eight structure is set up. 2 ? 4 order harmonic pulse train with stable amplitude has been obtained when the RF modulation frequency is about 2.5 GHz.
Wang, Zhaoying; Yu, Zhenhong; Gao, Peiliang; Yang, Tianxin; Zhang, Ruifeng; Jia, Dongfang; Li, Shichen
2003-05-01
424
Harmonic and rational-harmonic mode-locking of erbium-doped fiber lasers (EDFLs) with wavelength tunability is achieved by seeding optical pulses from a gain-switched Fabry-Perot laser diode that is feedback-injection controlled with the slave EDFLs via optical circulator.
Lin, Gong-Ru; Chang, Yung-Cheng
2002-08-01
425
E-print Network
ABSTRACT The goal of this research was to develop an optical amplifier based on Erbium doped GaN waveguides, which can be used in the next-generation of planar integrated optic circuits. This thesis started from the basic concepts of fiber optic...
Wang, Qian
2012-05-31
426
We extend the results of our previous work (2005) to increase the robustness of an L2 nonlinear controller applied to an erbium doped fiber amplifier (EDFA). We consider the rejection of input and state uncertainties to a full information (FI) extended state space model of the EDFA. The generic robust stabilization problem is solved and the concept of state uncertainty
Nem Stefanovic; Lacra Pavel
2006-01-01
427
We present a detailed study of a set of models for characterizing the gain, the input and output powers of single erbium-doped fiber amplifiers (EDFAs) and networks of EDFAs. The time dependent gain is described by a single ordinary differential equation for the average inversion level of an EDFA with arbitrary number of signal channels with arbitrary power levels and
Y. Sun; J. L. Zyskind; A. K. Srivastava
1997-01-01
428
An analysis of transient gain dynamics in erbium-doped fiber amplifiers is presented to provide a qualitative explanation of its time constants. The theory yields analytical solutions at the fiber amplifier input end, making it convenient to study the time dependence of gain saturation and recovery under changing input signal conditions. It is shown that, independently of the pump wavelength, gain
E. Desurvire
1989-01-01
429
SciTech Connect
Subnanosecond pressure pulses were observed on the surface of water irradiated by 200-ns, 2.94-{mu}m, 0.65-0.8-J cm{sup -2} pulses from a Q-switched erbium laser. The pulses can be related to the development of explosive boiling up in a thin subsurface layer of the overheated water. (letters)
Samokhin, A A; Vovchenko, V I; Il'ichev, N N [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Shapkin, P V [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
2007-12-31
430
E-print Network
Sensitization of erbium by ytterbium in Er[subscript x]Yb[subscript 2-x]SiO[subscript 5] thin films at 980nm optical excitation is demonstrated by means of comparison of the 1.54?m photoluminescence intensities excited ...
Vanhoutte, Michiel
431
We propose a new concept to produce switchable multiwavelength oscillations with a cascaded fiber Bragg grating overlapping cavity erbium-doped fiber laser. The laser can be designed to operate in multiwavelength or in wavelength switching modes. The different lines have different thresholds. For three-wavelength oscillation, the output powers are linear or piecewise linear functions of the input pump power. An output
Qinghe Mao; John W. Y. Lit
2002-01-01
432
Simultaneous continuous wave multiwavelength operation of an erbium-doped fiber laser has been demonstrated using two types of recently developed in-fiber grating comb filters. The lasing wavelengths and linewidths were determined by the comb filter, which was inserted in a ring cavity with a single inhomogeneously broadened gain medium.
Jong Chow; Graham Town; Ben Eggleton; Morten Ibsen; Kate Sugden; Ian Bennion
1996-01-01
433
Room temperature multifrequency erbium-doped fiber (EDF) lasers anchored on the ITU frequency grid and using frequency periodic filters are presented. The multifrequency operation is demonstrated both theoretically and experimentally by adding a frequency shifter in the ring cavity to prevent steady-state laser operation and single-frequency oscillation
Antoine Bellemare; Miroslav Karasek; Martin Rochette; S. LRochelle; Michel Têtu
2000-01-01
434
An effective method for achieving a room-temperature multiwavelength erbium-doped fiber ring laser is presented. Simultaneous multiwavelength lasing with 0.5-nm intervals is achieved both experimentally and theoretically by addition of sinusoidal phase modulation in the ring cavity to prevent single-wavelength oscillation.
Kejiang Zhou; Dongyun Zhou; Fengzhong Dong; Nam Quoc Ngo
2003-01-01
435
E-print Network
We demonstrate a 7-core erbium doped fiber amplifier employing side pumping using tapered multimode fiber. The amplifier has multicore inputs and outputs which can be readily spliced to multicore transmission fiber for amplifying space division multiplexed signals. Gain over 25dB was obtained in each of the cores over a 40-nm bandwidth covering C-band.
Abedin, Kazi; Thierry, Taunay; Zhu, Benyuan; Yan, Man; Bansal, Lalit; Dimarcello, Frank; Monberg, Eric; DiGiovanni, David
2013-01-01
436
In conventional aesthetic rhinoplasty operations, manual or powered rasps are used to reduce the osseo-cartilagenous nasal dorsum. This tactile method requires palpation of the instrument and the dorsum during surgery to estimate the degree of volume reduction, and often requires forceful manipulation of the dorsum which may illicit pain during surgery and contribute to post-operative edema and echymosis. In this preliminary study, we investigated the use of the Erbium:YAG laser ((lambda) equals294 micrometers ) to reduce bone and cartilage using ex-vivo porcine nasal dorsum and human cadaveric tissues. The short pulsed length and high absorption of this laser in biologic tissues results in minimization of thermal injury which are ideal for non- contact optical contouring of osseous and cartilagenous tissues in the face. Two Erbium:YAG lasers were used to ablate fresh porcine nasal bone and compared for their use. One Erbium:YAG laser, the Fidelis Laser, Fontana Medical Lasers, Ljubljana, Slovenija with variable pulse repetition rates (2 to 50 Hz), pulse energy (80 to 1000 mJ), and pulse duration (100, 300, 750 and 1000 microsecond(s) ) was used and compared to the Ultrafine Erbium:YAG laser, Coherent Inc., Santa Clara California, with variable pulse repetition rate (2 to 10 Hz), pulse energy (2-16 J/cm2), and spot diameter (2-6 mm). Only laser parameters approximating the conditions for thermal confinement were evaluated.
Truong, Mai T.; Majaron, Boris; Pandoh, Nidhi S.; Wong, Brian J.
2001-05-01
437
E-print Network
. Francis Rensselaer Polytechnic Institute, Environmental and Energy Engineering Department Troy, New York.O. Box 1072, Schenectady, New York 12301-1072 Received December 12, 1996 Accepted July 8, 1997 Abstract transmission measurements of rare earth metal samples of holmium, erbium, and thulium and isotopically enriched
Danon, Yaron
438
Optically excited erbium ions incorporated near the surface of a silica glass decay by spontaneous emission and---at high Er concentration---via Förster energy transfer to quenching sites. By externally modifying the photonic microstructure we vary the local optical density of states (LDOS) in samples with different degrees of Förster transfer. Changes in spontaneous emission rate are consistent with calculated variations in
M. J. A. de Dood; J. Knoester; A. Tip; A. Polman
2005-01-01
439
SciTech Connect
Increasing demand for higher bandwidth has driven the need for higher Wavelength Division Multiplexing (WDM) channels. One of the requirements to achieve this is a broadband amplifier. This paper reports the performance of a broadband, compact, high-concentration and silica-based erbium-doped fiber amplifier. The amplifier optimized to a 2.15 m long erbium-doped fiber with erbium ion concentration of 2000 ppm. The gain spectrum of the amplifier has a measured amplification bandwidth of 100 nm using a 980 nm laser diode with power of 150 mW. This silica-based EDFA shows lower noise figure, higher gain and wider bandwidth in shorter wavelengths compared to Bismuth-based EDFA with higher erbium ion concentration of 3250 ppm at equivalent EDF length. The silica-based EDF shows peak gain at 22 dB and amplification bandwidth between 1520 nm and 1620 nm. The lowest noise figure is 5 dB. The gain is further improved with the implementation of enhanced EDFA configurations.
Hajireza, P.; Shahabuddin, N. S.; Abbasi-Zargaleh, S.; Emami, S. D.; Abdul-Rashid, H. A.; Yusoff, Z. [Center for Advanced Devices and Systems, Faculty of Engineering, Multimedia University, 63100 Cyberjaya (Malaysia)
2010-07-07
440
A dual-wavelength linear cavity erbium-doped fiber (EDF) laser based on a fiber grating pair is demonstrated experimentally. A circulator, a 980nm/1550nm wavelength division multiplexing (WDM) coupler, a 1×2 coupler, a polarization controller, a 6m long erbium-doped fiber and a fiber grating pair for wavelength interval of 0.3nm are included in the structure. A circulator connected at two ports as reflecting mirror structure. A 980nm pump source pump an erbium-doped fiber with a length of 6m consist of an erbium doped fiber amplifier. Through adjusting the state of the polarization controller, the transmission characteristic of cavity is changed. In both polarization and wavelength, the feedback from the fiber grating pair results in the laser operating on two longitudinal modes that are separated. The birefringence induced by the fiber grating pair is beneficial to diversify the polarization states of different wavelength in the erbium-doped fiber. So it is enhanced the polarization hole burning effect. This polarization hole burning effect greatly reduced the wavelength competition. Then, it was possible to achieve stable dual-wavelength. It turns out the structure generated the stable dual-wavelength with the 0.3nm wavelength interval and the output power is 0.13dBm in the end. The whole system have a simple and compact structure, it can work stably and laid a foundation for microwave/millimeter wave generator. It has a good application performance in the future for scientific research and daily life.
Sun, Hongwei; Wang, Tianshu; Jia, Qingsong; Zhang, Peng; Jiang, Huilin
2014-12-01
441
PubMed
An optical receiver system composing 13 serial data restore/synchronizer modules and a single module combiner converted optical 32-bit serial data into 32-bit synchronous parallel data for a computer to acquire 152-channel magnetoencephalography (MEG) signals. A serial data restore/synchronizer module identified 32-bit channel-voltage bits from 48-bit streaming serial data, and then consecutively reproduced 13 times of 32-bit serial data, acting in a synchronous clock. After selecting a single among 13 reproduced data in each module, a module combiner converted it into 32-bit parallel data, which were carried to 32-port digital input board in a computer. When the receiver system together with optical transmitters were applied to 152-channel superconducting quantum interference device sensors, this MEG system maintained a field noise level of 3 fT/?Hz @ 100 Hz at a sample rate of 1 kSample/s per channel. PMID:25430154
Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong
2014-11-01
442
The thermal diffusivity of R152a was measured by dynamic light scattering. We have developed an apparatus which enables us\\u000a to apply both homodyne and heterodyne light-scattering techniques allowing a wide region of state to be investigated. A total\\u000a of 300 data points was obtained along the critical isochore. in both coexisting phases and on seven isotherms with densities\\u000a and temperatures
B. Kruppa; J. Straub
1997-01-01
443
We report the experimental demonstration of a novel distributed fiber-optic strain sensor by localizing a dynamic grating in polarization maintaining erbium-doped fiber (PM-EDF) using the technique of synthesis of optical coherence function (SOCF).
Xinyu Fan; Zuyuan He; K. Hotate
2006-01-01
444
E-print Network
485 Stopping power and straggling of 0.2-2.0 MeV protons and 0.3-3.1 MeV 4He ions in erbium J. C des protons et des ions 4He dans des couches minces d'erbium, évaporées sous vide, ont été déterminées straggling of protons and 4He ions in erbium films evaporated in vacuum, were determined using
445
E-print Network
-Based Erbium-Doped Fiber Ring Laser With 106-nm Tuning Range H. L. Liu, H. Y. Tam, Senior Member, IEEE, W. H lasers using 84.6-cm-long lanthanum-codoped bismuth-based erbium doped fiber and a narrow-band tunable)-codoped bismuth-based erbium-doped fiber (Bi-EDF), laser tuning, microelectromechanical system (MEMS) filter. I
Wai, Ping-kong Alexander
446
E-print Network
103 �TUDE PAR DIFFRACTION DE NEUTRONS DES STRUCTURES CRISTALLINE ET MAGN�TIQUE DE L'ORTHOFERRTTE D'ERBIUM seconde, au-dessous de TN = 4,4 ± 0,1 K, de la configuration Gz à la configuration Gy. Au-dessous de TN, l'erbium. - Les orthoferrites de terres rares et parmi eux, l'orthoferrite d'erbium, ont d6jd fait l'objet de
447
E-print Network
Botanical Journal of the Linnean Society, 2006, 152, 271Â278. With 3 figures © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 152, 271Â278 271 Blackwell Publishing deception and specific flo- ral mimicry. © 2006 The Linnean Society of London, Botanical Journal
Hammerton, James
448
We report on the first application of in-flight fast-timing measurements, a method developed in order to directly measure lifetimes in the picosecond to nanosecond range. As a proof of principle of the method, lifetimes of the states belonging to the ground-state band in Sm152 are measured up to the 81+ state. An excellent agreement with recommended values is found. A slightly improved determination of the spectroscopic quadrupole moment of the 41+ state is also reported. In-flight fast-timing measurements open interesting opportunities for future studies of collective properties in radioactive nuclei.
Plaisir, C.; Gaudefroy, L.; Méot, V.; Blanc, A.; Daugas, J. M.; Roig, O.; Arnal, N.; Bonnet, T.; Gobet, F.; Hannachi, F.; Tarisien, M.; Versteegen, M.; Roger, T.; Rejmund, M.; Navin, A.; Schmitt, C.; Fremont, G.; Goupil, J.; Pancin, J.; Spitaels, C.; Zieli?ska, M.
2014-02-01
449
NSDL National Science Digital Library
This is a set of resource materials for second-semester introductory physics, developed at the University of Virginia. The unifying theme of the course is applying Newtonâs Laws to a small segment of a large system to find laws governing the system as a whole. Resources include complete lecture notes, demonstrations, links to related interactive simulations, problem sets/study sheets for students, and downloadable animated spreadsheets. Physics 152 covers topics that include gravity, waves and oscillations, fluids, heat, and thermodynamics. It is intended for prospective physics majors or students who have some preparation in the fundamentals of calculus.
Fowler, Michael
2009-02-24
450
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
Photocopy of copy of blueprint between pages 151 and 152 in completion report and history of the U.S.A. General hospital no. 21, compiled and edited under the direction of Major W.J. Cameron, by T.R. Wieger, Chief Engineer. The report was dated April 1, 1919. A copy of the report (4003/14/29) is at the National Archives, military records (floor 13 W), Washington, D.C. - Fitzsimons General Hospital, Bounded by East Colfax to south, Peoria Street to west, Denver City/County & Adams County Line to north, & U.S. Route 255 to east, Aurora, Adams County, CO
451
PubMed
We demonstrate a multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing. The wider channel spacing is realized by circulating the odd-order Stokes signals in the Brillouin gain medium through a four-port circulator. The circulated odd-order Stokes signals are amplified by the Brillouin gain and thus produce even-order Stokes signals at the output. These signals are then amplified by erbium gain block to form a ring-cavity laser. Ten channels with 0.174 nm spacing that are generated at 0.5 mW Brillouin pump power and 150 mW pump power at 1480 nm can be tuned from 1556 nm to 1564 nm. The minimum optical signal-to-noise ratio of the generated output channels is 30 dB with maximum power fluctuations of ±0.5 dB. PMID:21368983
Shee, Y G; Al-Mansoori, M H; Ismail, A; Hitam, S; Mahdi, M A
2011-01-31
452
NASA Technical Reports Server (NTRS)
The development of efficient and compact light sources operating at 1.54 micron is of enormous importance for the advancement of new optical communication systems. Erbium (1%) doped fiber amplifiers (EDFA's) or semiconductor lasers are currently being employed as near infrared light sources. Both devices, however, have inherent limitations due to their mode of operation. EDFA's employ an elaborate optical pumping scheme, whereas diode lasers have a strongly temperature dependent lasing wavelength. Novel light emitters based on erbium doped III-V semiconductors could overcome these limitations. Er doped semiconductors combine the convenience of electrical excitation with the excellent luminescence properties of Er(3+) ions. Electrically pumped, compact, and temperature stable optoelectronic devices are envisioned from this new class of luminescent materials. In this paper we discuss the potential of Er doped GaN for optoelectronic applications based on temperature dependent photoluminescence excitation studies.
Thaik, Myo; Hommerich, U.; Schwartz, R. N.; Wilson, R. G.; Zavada, J. M.
1998-01-01
453
In this paper, we consider a generalized Hirota-Maxwell-Bloch system with the higher-order dispersion and self-steepening effects, which describes the propagation of ultrashort optical pulse in the inhomogeneous erbium-doped fiber. Under certain coefficient constraints, N-soliton solutions are obtained through the Hirota method and symbolic computation. Soliton interactions are graphically presented and analyzed in the different fibers. Compared with the Hirota equation without the Maxwell-Bloch parts, the self-induced transparency effect caused by the doped erbium atoms is found to lead to the change of the soliton velocity and phase. In addition, the amplitudes and widths of solitons are respectively observed to decrease and increase in the dispersion-decreasing and dispersion-increasing fibers. Finally, we give the modulational instability condition through the linear stability analysis.
Wang, M.; Tian, B.; Qi, F.-H.; Qin, B.; Lin, Z.-Q.
2012-09-01
454
We consider a 3D cellular model of human tooth enamel and a photomechanical cellular model of enamel ablation by erbium laser radiation, taking into account the structural peculiarities of enamel, energy distribution in the laser beam cross section and attenuation of laser energy in biological tissue. The surface area of the texture in enamel is calculated after its micromachining by erbium laser radiation. The influence of the surface area on the bond strength of enamel with dental filling materials is discussed. A good correlation between the computer simulation of the total work of adhesion and experimentally measured bond strength between the dental filling material and the tooth enamel after its micromachining by means of YAG : Er laser radiation is attained.
Belikov, A. V.; Skrypnik, A. V.; Shatilova, K. V.
2014-08-01
455
In this work, a photo-annealing effect of gamma-irradiated erbium-doped glass fibre is investigated. Two commercial erbium-doped fibres (EDFs) with different doping concentrations were sealed inside a chamber with a cobalt-60 gamma source for 6 h to give an accumulated dose of 3.18 kGy. A tunable femtosecond pulsed laser with a repetition rate of 80 MHz was then used to pump EDF to generate 1550 nm fluorescence and green up-conversion emission, resulting in the annealing effect of the gamma-irradiated EDF. The fluorescence power of gamma-irradiated EDF with a moderate level of doping was almost returned to the initial state by photo-annealing, unlike that of a heavily doped EDF. This finding may facilitate the development of anti-irradiated superfluorescence fibre source for space navigation.
Hsiung Chang, Sheng; Liu, Ren-Young; Lin, Chu-En; Chou, Fong-In; Tai, Chao-Yi; Chen, Chii-Chang
2013-12-01
456
A passively mode-locked, bismuth-erbium-co-doped fiber (Bi-EDF) with a pulse width of 460 fs is proposed and demonstrated. A highly doped, 180-cm Bi-EDF with an erbium concentration of 3,250 ppm/wt and an absorption rate of 133 dB/m at 1,530 nm serves as the gain medium. The cavity is 11.6 m long with an overall group velocity dispersion of +0.063 ps2. The output pulses have a repetition rate, average output power, pulse energy and peak power of 11.18 MHz, 5 mW, 448 pJ and 1 kW, respectively. The system has a high beam quality and a narrow pulse width output in the L-band region.
Ahmad, H.; Zulkifli, A. Z.; Muhammad, F. D.; Zulkifli, M. Z.; Thambiratnam, K.; Harun, S. W.
2014-06-01
457
A multi-wavelength Erbium-doped fiber (EDF) laser based on four-wave-mixing is proposed and experimentally demonstrated. The 5km single mode fiber in the cavity enhances the four-wave-mixing to suppress the homogenous broadening of the erbium-doped fiber and get the stable multi-wavelength comb. The lasing stability is investigated. When the pump power is 300mW, the fiber laser has 5-lasing lines and the maximum fluctuation of the output power is about 3.18dB. At the same time, a laser with 110m high nonlinear fiber (HNFL) is demonstrated. When the pump power is 300mW, it has 7-lasing lines (above -30dBm) and the maximum fluctuation is 0.18dB.
Wang, Pinghe; Liu, Yong; Yu, Xuecai
2013-08-01
458
We demonstrate a simple tunable L-band multiwavelength Brillouin-Erbium fiber laser that utilizes a short passive erbium doped fiber (PEDF) as an absorber section. The impact of including the PEDF absorber section on the laser tunability is investigated. The proposed laser structure exhibits a wide tuning range of 24.4 nm (from 1583.5 nm to 1607.9 nm) at 1480 nm pump and Brillouin pump powers of 100 and 4 mW, respectively. This tuning range represents a 31% increase compared with a laser without a PEDF absorber section. The average number of stable output channels produced within this wavelength range is 16 channels with a spacing of 0.089 nm.
Al-Mashhadani, T. F.; Al-Mansoori, M. H.; Jamaludin, M. Z.; Abdullah, F.; Abass, A. K.; Rawi, N. I. M.
2013-12-01
459
E-print Network
We demonstrate fast and accurate control of the evolution of collective atomic coherences in an Erbium doped solid using external electric fields. This is achieved by controlling the inhomogeneous broadening of Erbium ions emitting at 1536 nm using an electric field gradient and the linear Stark effect. The manipulation of atomic coherence is characterized with the collective spontaneous emission (optical free induction decay) emitted by the sample after an optical excitation, which does not require any previous preparation of the atoms. We show that controlled dephasing and rephasing of the atoms by the electric field result in collapses and revivals of the optical free induction decay. Our results show that the use of external electric fields does not introduce any substantial additional decoherence and enables the manipulation of collective atomic coherence with a very high degree of precision on the time scale of tens of ns. This provides an interesting resource for photonic quantum state storage and quantum state manipulation.
Ji?í Miná?; Björn Lauritzen; Hugues de Riedmatten; Mikael Afzelius; Christoph Simon; Nicolas Gisin
2009-07-24
460
SciTech Connect
The negative parity states and some electromagnetic transition properties of even-odd erbium isotopes ({sup 159,161,163,165}Er) were studied within the framework of the interacting boson-fermion model. The single fermion is assumed to be in one of the lh{sub 9/2},3p{sub 3/2},2f{sub 5/2}, and 3p{sub 1/2} single-particle orbits. It was found that the calculated negative parity state energy spectra of the even-odd erbium isotopes agree quite well with the experimental data. The B(E2) values were also calculated and compared with the experimental data.
Yazar, Harun Resit; Uluer, Ihsan [Kirikkale University, Faculty of Art and Science, Kirikkale (Turkey)
2007-03-15
461
E-print Network
Erbium doped solids are potential candidates for the realization of a quantum memory for photons at telecommunication wavelengths. The implementation of quantum memory proposals in rare earth ion doped solids require spectral tailoring of the inhomogeneous absorption profile by efficient population transfer between ground state levels (spin polarization) using optical pumping. In this article we investigate the limiting factors of efficient optical pumping between ground state Zeeman levels in an erbium doped Y2SiO5 crystal. We introduce two methods to overcome these limiting factors: stimulated emission using a second laser and spin mixing using radio frequency excitation. Both methods significantly improve the degree of spin polarization. Population transfer between two Zeeman levels with less than 10 % of the total population in the initial ground state is achieved, corresponding to a spin polarization greater than 90 %. In addition, we demonstrate spectral tailoring by isolating a narrow absorption peak within a large transparency window.
B. Lauritzen; S. R. Hastings-Simon; H. de Riedmatten; M. Afzelius; N. Gisin
2008-08-26
462
SciTech Connect
A series of [(70TeO{sub 2}?(30?x)ZnO?xPbO){sub 0.99}?(Er{sub 2}O{sub 3}){sub 0.01}; where x = 5, 10, 15 and 20] tellurite glasses, were prepared using the melt quenching technique. Crucial emission bandwidth of erbium at 1.5 ?m has been derived and found to be the same for all the glasses, irrespective of PbO content. This identical bandwidth in all tellurite glasses is attributed to the presence of erbium in tellurium rich disordered environments. This result has been complemented through XANES spectra and the obtained invariant first shell of 6.5 oxygen atoms, confirm the unchanged environment in these glasses for all PbO content.
Ramamoorthy, Raj Kumar [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad-500046 (India); Bhatnagar, Anil K., E-mail: [email protected] [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad-500046, India and School of Physics, University of Hyderabad, Hyderabd-500046 (India)
2014-04-24
463
PubMed
Spiral-waveguide amplifiers in erbium-doped aluminum oxide on a silicon wafer are fabricated and characterized. Spirals of several lengths and four different erbium concentrations are studied experimentally and theoretically. A maximum internal net gain of 20 dB in the small-signal-gain regime is measured at the peak emission wavelength of 1532 nm for two sample configurations with waveguide lengths of 12.9 cm and 24.4 cm and concentrations of 1.92 × 10(20) cm(-3) and 0.95 × 10(20) cm(-3), respectively. The noise figures of these samples are reported. Gain saturation as a result of increasing signal power and the temperature dependence of gain are studied. PMID:25401633
Vázquez-Córdova, Sergio A; Dijkstra, Meindert; Bernhardi, Edward H; Ay, Feridun; Wörhoff, Kerstin; Herek, Jennifer L; García-Blanco, Sonia M; Pollnau, Markus
2014-10-20
464
PubMed
Lasers for use in space-borne applications require ultrahigh efficiency due to limited heat dissipation and power generation capacity. In particular, interplanetary optical communication systems require high-efficiency, moderate-power (>4 W) optical transmitters in the 1600 nm wavelength range. Resonantly pumped dual-clad erbium-doped fiber lasers are best suited for this purpose. Parametric numerical optimizations are performed using a two-level propagation model modified to include spatial effects specific to large-mode-area fibers. Propagation loss mechanisms are found to be limiting factors due to the relatively low cross-sections and low quenching-free doping densities of erbium. Although experimental reports have demonstrated efficiencies up to 33%, simulation results indicate that over 53% power-conversion efficiency can be achieved using commercial fibers, and over 75% can be achieved using custom fibers employing propagation-loss mitigation strategies. PMID:23759839
Yao, Haomin; Wright, Malcolm W; Marciante, John R
2013-06-10
465
Erbium is one of the rare earth elements which are used to produce therapeutic radioisotopes by charged particle induced reactions, such as proton, deuteron and alpha particle-induced reactions. In this study, production cross sections of 165Tm and 166Tm were measured for erbium samples irradiated by a proton beam with E=45 MeV provided by the MC-50 cyclotron of KIRAMS (Korea Institute of Radiological and Medical Sciences). A HPGe detector was used to measure ?-rays for an activation cross section measurement. A stacked foil technique was adopted to measure the activation cross sections at different proton energies using copper foils as degraders and monitor foils to measure the proton beam current. The SRIM code was used to calculate the energy of the proton beam penetrating each foil. The measured data are compared with other available experimental data and theoretical cross sections calculated by TALYS code.
Song, T. Y.; Kim, J. W.; Kim, H. I.; Lee, C. W.; Lee, Y. O.; Yang, S. C.; Kim, K. S.; Kim, G. N.
2014-05-01
466
PubMed
An all-single-mode-fiber L-band superfluorescent fiber source (SFS) with 1 W output power, 34.3 nm bandwidth (FWHM) and 54% optical conversion efficiency is constructed by seeding a high power erbium-doped fiber amplifier (EDFA) with a low power L-band ASE seed source to avoid parasitic lasing. The source is resonantly pumped by a high power C-band SFS peaked at 1545 nm. PMID:18521149
Chen, Sheng-Ping; Liu, Ze-Jin; Li, Yi-Gang; Lu, Ke-Cheng; Zhou, Shou-Huan
2008-01-01
467
PubMed Central
We report a large normal dispersion erbium-doped fiber laser with self-similar pulse evolution in the gain fiber. The cavity is stabilized by the local nonlinear attractor in the gain fiber through the use of a narrow filter. Experimental results are accounted for by numerical simulations. This laser produces 3.5 nJ pulses, which can be dechirped to 70 fs with an external grating pair. PMID:24562267
Liu, Hui; Liu, Zhanwei; Lamb, Erin S.; Wise, Frank
2014-01-01
468
SciTech Connect
We have investigated phase transitions in elemental erbium in a diamond anvil cell up to 65 GPa using x-ray powder diffraction methods. We present preliminary evidence of a series of phase transitions that appear to follow the expected hcp {yields} Sm-type {yields} dhcp {yields} distorted fcc sequence. In particular, we believe that we have evidence for the predicted dhcp {yields} distorted fcc transition between 43 GPa and 65 GPa.
Pravica, M.G.; Lipinska-Kalita, K.; Quine, Z.; Romano, E.; Nicol, M.F. (UNLV)
2006-02-02
469
The effect of ytterbium co-doping on erbium ion clustering in silica-based glass was studied. It was experimentally shown that the pump-to-signal conversion efficiency could be significantly increased if the number of Yb3+ ions in the fiber core was 20 times higher than the number of Er3+ ions. Estimations of the number of Er3+ ions in clusters confirmed a decrease in their clustering at high Yb concentrations.
Kiritchenko, N. V.; Kotov, L. V.; Melkumov, M. A.; Likhachev, M. E.; Bubnov, M. M.; Yashkov, M. V.; Laptev, A. Yu; Guryanov, A. N.
2015-02-01
470
A noise figure of 2.9±0.4 dB, measured in a high-gain erbium-doped fiber amplifier for input signals in the range -35 to -15 dBm and for pump powers of >5.8 mW, is discussed. The spontaneous emission factor nsp was 0.99±0.09 for input signals less than -15 dBm. These low figures are attributable to the optimized fiber design and the use of
R. I. Laming; D. N. Payne
1990-01-01
471
We study the bandwidth and multiplexing capacity of an erbium-doped optical memory for quantum storage purposes. We concentrate on the protocol revival of a silenced echo because it has the largest potential multiplexing capacity. Our analysis is applicable to other protocols that involve strong optical excitation. We show that the memory performance is limited by instantaneous spectral diffusion and we describe how this effect can be minimized to achieve optimal performance.
Dajczgewand, J.; Ahlefeldt, R.; Böttger, T.; Louchet-Chauvet, A.; Le Gouët, J.-L.; Chanelière, T.
2015-02-01
472
E-print Network
We report on the observation of dispersion-managed (DM) dark soliton emission in a net-normal dispersion erbium-doped fiber laser. We found experimentally that dispersion management could not only reduce the pump threshold for the dark soliton formation in a fiber laser, but also stabilize the single dark soliton evolution in the cavity. Numerical simulations have also confirmed the DM dark soliton formation in a fiber laser.
Han Zhang; Dingyuan Tang; Mustapha Tlidi; Luming Zhao; Xuan Wu
2010-07-19
473
By writing several loss-inducing photosensitive side-tap Bragg gratings in a short length of optical fibre, the gain variation of +\\/- 1.6 dB over a bandwidth of 33 nm in a saturated erbium doped fibre amplifier is reduced to +\\/- 0.3 dB. It is shown for the first time that these gratings may be written with predictable ease.
R. Kashyap; R. Wyatt; P. F. McKee
1993-01-01
474
Experiments with erbium-doped fiber lasers demonstrate cw, sinusoidal, and self-pulsing operation. The obtained regimes depend on three control parameters: ion-pair concentration, photon lifetime, and pumping rate. We present a theoretical model which describes the active medium as a mixture of isolated ions and ion pairs. Starting with the adapted laser rate equations we show that the description of the dynamical
François Sanchez; Patrice Le Boudec; Pierre-Luc François; Guy Stephan
1993-01-01
475
Amplification of spontaneous emission (ASE) in erbium-doped single-mode fiber amplifiers operating at ?=1.53 ?m is studied theoretically and experimentally. The ASE noise spectra obtained from the theory are found to be in excellent quantitative agreement with the experimental data. The observed changes in ASE spectral shapes under different population inversion conditions are also explained. The model may be used to
Emmanuel Desurvire; JAY R. SIMPSON
1989-01-01
476
Erbium-doped fiber has become the central component of nearly all optical amplifiers. Applications reported include repeaters, power amplifiers, preamplifiers, and distributed amplifiers. To date, nearly all the fiber used in these devices has been silica based and fabricated by variations on the major telecommunications fiber technology. Disadvantages of the silica-based host glass, such as low solubility of the rare-earth ions
B. James Ainslie
1991-01-01
477
Simultaneous lasing at up to 24 wavelengths is demonstrated in an erbium-doped fiber-ring laser using a simple design. This result is achieved using a low-loss cavity, controlled polarization evolution and liquid nitrogen cooling to enhance spectral hole-burning, polarization hole-burning, and polarization selectivity. The design does not include any wavelength-selective components; instead, it utilizes wavelength selectivity provided by polarization evolution in
Paul F. Wysocki
1996-01-01
478
E-print Network
We study the bandwidth and multiplexing capacity of an erbium-doped optical memory for quantum storage purposes. We concentrate on the protocol ROSE (Revival of a Silenced Echo) because it has the largest potential multiplexing capacity. Our analysis is applicable to other protocols that involve strong optical excitation. We show that the memory performance is limited by instantaneous spectral diffusion and we describe how this effect can be minimised to achieve optimal performance.
Julian Dajczgewand; Rose Ahlefeldt; Thomas Böttger; Anne Louchet-Chauvet; Jean-Louis Le Gouët; Thierry Chanelière
2014-09-19
479
Numerical solution of a general rate-equation model of an erbium-doped fiber amplifier highlights several important features of the device. A difference in strong-signal gain between copropagating and counterpropagating signal pump schemes in the presence of pump excited-state absorption is predicted, and this is confirmed by experiment. The detriment in the noise figure previously associated with counterpropagating schemes for only small-signal
P. R. Morkel; Richard I. Laming
1989-01-01
480
E-print Network
We report on the observation of dispersion-managed (DM) dark soliton emission in a net-normal dispersion erbium-doped fiber laser. We found experimentally that dispersion management could not only reduce the pump threshold for the dark soliton formation in a fiber laser, but also stabilize the single dark soliton evolution in the cavity. Numerical simulations have also confirmed the DM dark soliton formation in a fiber laser.
Zhang, Han; Tlidi, Mustapha; Zhao, Luming; Wu, Xuan
2010-01-01
481
Signal propagation and noise accumulation in lightwave systems using saturated optical amplifiers as repeaters are analyzed. Numerical simulations of amplified spontaneous emission in concatenated erbium-doped fiber amplifiers indicate that a reach beyond 10000 km is possible with a 1.55-?m system in the absence of fiber nonlinearities. Distributed optical amplifiers are shown to have low noise, but require higher pump power
C. R. Giles; Emmanuel Desurvire
1991-01-01
482
We use for what we believe is the first time narrow-band end-reflectors to reduce losses through short-wavelength amplified stimulated emission (ASE) in silica-based erbium-doped fiber amplifiers operating at wavelengths above 1570 mm. The end-reflectors feed a small fraction of the ASE, up to a few tenths of a milliwatt, back into the amplifying fiber. The reflected ASE compresses the short-wavelength
J. Nilsson; S. Y. Yun; S. T. Hwang; J. M. Kim; S. J. Kim
1998-01-01
483
Laser etching has an effect on the mineral content of dentin. The aim of this study was to evaluate the mineral content of\\u000a dentin prepared at three different power settings with an erbium, chromium:yttrium scandium gallium garnet (Er,Cr:YSGG) laser.\\u000a The enamel of five, lower, wisdom, molar teeth was removed to expose the dentin surface. Four dentin slabs were obtained,\\u000a then
Asli Secilmis; Subutayhan Altintas; Aslihan Usumez; Gizem Berk
2008-01-01
484
Since lasers were introduced in dentistry, there has been considerable advancement in technology. Several wavelengths have\\u000a been investigated as substitutes for high-speed air turbine. Owing to its high absorbability in water and hydroxyapatite,\\u000a the erbium:yttrium–aluminum–garnet (Er:YAG) laser has been of great interest among dental practitioners and scientists. In\\u000a spite of its great potential for hard tissue ablation, Er:YAG laser effectiveness
Vivian Colucci; Flávia Lucisano Botelho do Amaral; Jesus Djalma Pécora; Regina Guenka Palma-Dibb; Silmara Aparecida Milori Corona
2009-01-01
485
The dynamics of a unidirectional erbium-doped fiber laser is investigated on a time scale short enough to observe, with good resolution, its behavior for individual round-trips in the laser cavity. With an intracavity polarization controller, a rich variety of nonlinear phenomena, ranging from self-pulsing to square-wave antiphase patterns in two orthogonal states of polarization, are observed. These patterns evolve continuously
Q. L. Williams; J. García-Ojalvo; R. Roy
1997-01-01
486
Ion-exchange in glass is a simple, flexible technique to realize optical fiber-compatible planar waveguide devices. Recently, neodymium-doped waveguide lasers operating at 1060 and 1300 nm have been demonstrated in this technology. Lasers operating at 1540 nm are desirable for telecommunication applications and the authors report for the first time ion-exchanged waveguide lasers in erbium-doped glass emitting at this wavelength. Lasers
T. Feuchter; E. K. Mwarania; J. Wang; L. Reekie; J. S. Wilkinson
1992-01-01
487
Gain control in a long-wavelength (L-band) erbium-doped fiber amplifier (EDFA) using a counter-propagating ring resonator is demonstrated. The clamped gain can be controlled to be in the range from 7.0 to 18.0 dB for the 1580 nm signal at -30 dBm by tuning the oscillating laser in the range from 1565 to 1540 nm. The design prevents oscillating light from
2002-01-01
488
Erbium-doped fiber lasers (EDFLs) may soon find applications in space as high bit rate optical communication systems and photonic analog-to-digital converters (ADCs). The rapid advancement in digital signal processing systems has led to an increased interest in the direct digitization of high- frequency analog signals. The potential high bandwidth, reduced weight, and reduced power requirements makes photonics an attractive technology
Rebecca J. Bussjager; Michael J. Hayduk; Steven T. Johns; Linda R. Taylor; Edward W. Taylor
2002-01-01
489
Peptide-modified silver nanoparticles have been coated with an erbium-doped silica layer using a method inspired by silica biomineralization. Electron microscopy and small-angle X-ray scattering confirm the presence of an Ag/peptide core and silica shell. The erbium is present as small Er2O3 particles in and on the silica shell. Raman, IR, UV-Vis, and circular dichroism spectroscopies show that the peptide is still present after shell formation and the nanoparticles conserve a chiral plasmon resonance. Magnetic measurements find a paramagnetic behavior. In vitro tests using a macrophage cell line model show that the resulting multicomponent nanoparticles have a low toxicity for macrophages, even on partial dissolution of the silica shell.Peptide-modified silver nanoparticles have been coated with an erbium-doped silica layer using a method inspired by silica biomineralization. Electron microscopy and small-angle X-ray scattering confirm the presence of an Ag/peptide core and silica shell. The erbium is present as small Er2O3 particles in and on the silica shell. Raman, IR, UV-Vis, and circular dichroism spectroscopies show that the peptide is still present after shell formation and the nanoparticles conserve a chiral plasmon resonance. Magnetic measurements find a paramagnetic behavior. In vitro tests using a macrophage cell line model show that the resulting multicomponent nanoparticles have a low toxicity for macrophages, even on partial dissolution of the silica shell. Electronic supplementary information (ESI) available: Figures S1 to S12, Tables S1 and S2. See DOI: 10.1039/c1nr10930h
Mantion, Alexandre; Graf, Philipp; Florea, Ileana; Haase, Andrea; Thünemann, Andreas F.; Maši?, Admir; Ersen, Ovidiu; Rabu, Pierre; Meier, Wolfgang; Luch, Andreas; Taubert, Andreas
2011-12-01
490
PubMed Central
MicroRNAs (miRNAs) regulate the proliferation and metastasis of cancer cells. Here, we showed that miR-152 was downregulated in non-small-cell lung cancer (NSCLC) tissues and cell lines. Overexpression of miR-152 suppressed cell proliferation and colony formation and also limited migration and invasion. Fibroblast growth factor 2 (FGF2) was confirmed as a direct target of miR-152. FGF2 knockdown suppressed cell proliferation, colony formation, migration and invasion, whereas FGF2 overexpression partially reversed the suppressive effect of miR-152. Furthermore, the presence of miR-152 was inversely correlated with FGF2 in NSCLC tissues. Overall, this study demonstrated that miR-152 suppressed the proliferation and invasion of NSCLC cells by downregulating FGF2. These findings provide novel insights with potential therapeutic applications for the treatment of NSCLC. PMID:25190353
Cheng, Zhenshun; Ma, Rongli; Tan, Weijun; Zhang, Li
2014-01-01
491
We have fabricated new type of erbium doped fibre having core glass compositions of zirconia-yttria-alumino-phosphosilicate. With the proper combination of zirconia and aluminium with other codopants, high concentration of 4000 ppm erbium-ions was doped in the fibre core-glass by conventional MCVD and solution doping process without any phaseseparation. The fabricated fibre exhibited wide gain band-width covering both C and L bands. The optical gain and noise characteristics were studied for both single-channel and multi-channel amplification at C-band regime for different input signal levels. This novel zirconia-erbium-doped fibre (Zr-EDF) has produced intrinsically flat gain of maximum gaindifference of 2dB with average optical gain 22.5dB and noise figure of 4.5 dB for simultaneous four-channel amplification at input signal level of -30dBm/channel in the optimized condition. The performances of Zr-EDF in terms of gain-flattening and noise characteristics were found to be promising for small-signal multi-channel amplification which would be applicable in dense-wavelength division multiplexing (DWDM) system.
Pal, Mrinmay; Paul, Mukul C.; Das, Shyamal; Sen, Ranjan; Bhadra, Shyamal K.
2011-12-01
492
PubMed
We have investigated the characteristics of Brillouin-Erbium fiber laser (BEFL) with variation of Erbium-doped fiber amplifier (EDFA) locations in a ring cavity configuration. Three possible locations of the EDFA in the laser cavity have been studied. The experimental results show that the location of EDFA plays vital role in determining the output power and the tuning range. Besides the Erbium gain, Brillouin gain also contributes to the performance of the BEFL. By placing the EDFA next to the Brillouin gain medium (dispersion compensating fiber), the Brillouin pump signal is amplified thereby generating higher intensities of Brillouin Stokes line. This efficient process suppresses the free running self-lasing cavity modes from oscillating in cavity as a result of higher Stokes laser power and thus provide a wider tuning range. At the injected Brillouin pump power of 1.6 mW and the maximum 1480 nm pump power of 135 mW, the maximum Stokes laser power of 25.1 mW was measured and a tuning range of 50 nm without any self-lasing cavity modes was obtained. PMID:19582091
Hambali, Nor Azura Malini A; Mahdi, Mohd Adzir; Al-Mansoori, Mohammed Hayder; Abas, Ahmad Fauzi; Saripan, M Iqbal
2009-07-01
493
A tunable, single-longitudinal-mode (SLM) fiber laser based on a short length, highly doped zirconia–erbium doped fiber (Zr-EDF) is proposed and demonstrated. The Zr-EDF is a novel fiber with an erbium ion concentration of 4320?ppm?wt???1 and an absorption rate of approximately 22.0?dB?m???1 at 978?nm, while at the same time being highly compatible with conventional silica-based optical fibers. The Zr-EDF is used as the gain medium in the laser cavity, while a tunable C-band fiber Bragg grating is used to adjust the operating wavelength of the system, providing an operating wavelength range of between 1533.8?nm to 1545.0?nm. Two short erbium-doped fibers, with active ion concentrations of 900?ppm?wt???1, serve as saturable absorbers, and allow for an SLM output with a narrow laser linewidth of only 0.2?MHz. The proposed system has multiple applications as a tunable SLM laser for communications and sensing purposes.
Ahmad, H.; Thambiratnam, K.; Paul, M. C.; Harun, S. W.
2014-08-01
494
Er-doped Yttrium oxide (Er^3+:Y2O3) has gained recent attention for its possible use in optoelectronic devices. Here we report the use of atomic layer deposition (ALD) to synthesize thin films of Yttrium oxide with various doping levels of Erbium ions (Er^3+) using different chemistries. ALD uses self-limiting surface reactions to deposit highly conformal thin films over large areas and substrates of arbitrary shape. This allows for the uniform layered doping of Yttrium oxide with Er^3+. The spatial separation of the Erbium ions can be controlled using organometallic precursors with varying ligand sizes. The doping concentration (volume ratio of Er^3+ sites to Y^3+ sites) is controlled by the ratio of the precursor pulses. We comprehensively studied ALD-grown films of Er^3+:Y2O3 obtained from the Erbium precursors Er(MCp)3 and Er(BA)3 and the Yttrium precursors Y(MCp)3 and Y(Cp)3 using either water or hydrogen peroxide as an oxygen source. Detailed description of the studied optical and spectroscopic properties, stoichiometry, and physical characteristics of these films will be presented.
Becker, Nicholas; Proslier, Thomas; Klug, J.; Elam, J.; Sanamyan, T.; Dubinckii, M.; Girolami, J.; Pellin, M.
2011-03-01
495
We postulated that ablation of trabecular meshwork can be accomplished without damage to Schlemm's canal and adjacent tissue. We performed Erbium:YAG laser trabecular ablation on human autopsy eyes and confirmed the results by histopathologic examination. We used an Erbium:YAG laser (2.94 micrometers ) equipped with a sapphire probe and a quartz tip (350 micrometers diameter). Energy levels of 5, 10, 15, 20, and 40 mJ per pulse were used. The probe was placed directly onto the trabecular meshwork viewed through an operating microscope and focal ablation was performed with single pulses. The tissue was then processed and examined under light and scanning microscopy. The histopathologic study of the trabecular meshwork revealed that a single pulse at an energy level of 15 mJ was optimal for ablating through the trabecular meshwork to Schlemm's canal with a minimal amount of coagulative damage to the surrounding tissue. The mean width of ablated tissue was 150 micrometers +/- 29 micrometers (n equals 18) and the mean depth of ablation was 133 +/- 48 micrometers (n equals 18) at this energy level. The mean width of coagulative damage to adjacent tissue was 16 +/- 8 micrometers (n equals 18). The ablation and coagulative damage increased with increasing energy levels. The Erbium:YAG laser equipped with a contact probe effectively ablates trabecular meshwork with little surrounding coagulative damage. This feature may minimize scarring and result in a high long-term patency rate of outflow channels created by laser trabecular ablation.
Kramer, Theresa R.; Noecker, Robert J.; Snyder, Robert W.; Ellsworth, Lansing G.; Yarborough, J. Michael
1994-06-01
496
PubMed
Functional impairment of DNA damage response pathways leads to increased genomic instability. Here we describe the centrosomal protein CEP152 as a new regulator of genomic integrity and cellular response to DNA damage. Using homozygosity mapping and exome sequencing, we identified CEP152 mutations in Seckel syndrome and showed that impaired CEP152 function leads to accumulation of genomic defects resulting from replicative stress through enhanced activation of ATM signaling and increased H2AX phosphorylation. PMID:21131973
Kalay, Ersan; Yigit, Gökhan; Aslan, Yakup; Brown, Karen E; Pohl, Esther; Bicknell, Louise S; Kayserili, Hülya; Li, Yun; Tüysüz, Beyhan; Nürnberg, Gudrun; Kiess, Wieland; Koegl, Manfred; Baessmann, Ingelore; Buruk, Kurtulus; Toraman, Bayram; Kayipmaz, Saadettin; Kul, Sibel; Ikbal, Mevlit; Turner, Daniel J; Taylor, Martin S; Aerts, Jan; Scott, Carol; Milstein, Karen; Dollfus, Helene; Wieczorek, Dagmar; Brunner, Han G; Hurles, Matthew; Jackson, Andrew P; Rauch, Anita; Nürnberg, Peter; Karagüzel, Ahmet; Wollnik, Bernd
2011-01-01
497
SciTech Connect
The effect of the oxygen content (C{sub O{sub 2}}) in the gas mixture (20% of SiH{sub 4} + 80% of Ar) + O{sub 2} and the surface area of an erbium target (S{sub Er}) on the composition and Er{sup 3+} photoluminescence of amorphous a-SiO{sub x}:(H, Er, O) films prepared by dc magnetron sputtering has been investigated. Analysis of the experimental data shows that [Er-O] and [Er-O-Si-O] clusters are formed in the gas plasma due to the competing processes of oxidation and sputtering of Si and Er targets and to the interaction of [Si-O] and [Er-O] clusters with each other and with the oxygen in the gas phase. The discontinuities in the dependences of the contents of erbium-bound oxygen and erbium in a film, N{sub O}{sup Er-O} and N{sub Er} = f(C{sub O{sub 2}}, S{sub Er}), at C{sub O{sub 2}} {approx_equal} (5-6.5) mol % supports the hypothesis on the existence of different erbium clusters. The necessary conditions for preparing a-SiO{sub x}:(H, Er, O) films with the highest photoluminescence intensity of erbium ions at a wavelength of 1.54 {mu}m are determined.
Undalov, Yu.K.; Terukov, E.I.; Gusev, O.B.; Kudoyarova, V.Kh. [Ioffe Physicotechnical Institute, Russian Academy of Sciences, Politekhnicheskaya ul. 26, St. Petersburg, 194021 (Russian Federation)
2005-08-15
498
Code of Federal Regulations, 2010 CFR
...accessibility: Electronic and information technology. 6.152 Section 6...accessibility: Electronic and information technology. (a) When developing...or using electronic and information technology, the Commission...
2010-01-01
499
Code of Federal Regulations, 2011 CFR
...accessibility: Electronic and information technology. 6.152 Section 6...accessibility: Electronic and information technology. (a) When developing...or using electronic and information technology, the Commission...
2011-01-01
500
E-print Network
MOSSBAUER STUDIES OF DILUTE ERBIUM IMPURITIES IN ZIRCONIUM HYDRIDES* G.K. Shenoy, B.D. Dunlap, D'impuretés d'erbium diluées dans le composé ô-ZrHi,5 de structure fluorine et e-ZrHi,85 de structure fluorine
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https://worldwidescience.org/topicpages/s/singly+ionized+phosphorus.html | #### Sample records for singly ionized phosphorus
1. Electron impact single ionization of copper
Electron impact single ionization cross sections of copper have been calculated in the binary encounter approximation using accurate expression for as given by Vriens and Hartree–Fock momentum distribution for the target electron. The BEA calculation based on the usual procedure does not show satisfactory ...
2. Single Photon Double Ionization of Atomic Oxygen
Science.gov (United States)
Wickramarathna, Madhushani; Gorczyca, Thomas; Ballance, Connor; Stolte, Wayne
2017-04-01
Single photon double ionization cross sections are calculated using an R-matrix with pseudostates (RMPS) method which was recently applied by Gorczyca et al. for the double photoionization of helium. With the convergence of these theoretical calculations for the simple case of helium, we extend this methodology to consider the more complex case of oxygen double photoionization. We compare our calculated results with recent measurements at the Advanced Light Source, as well as earlier experimental measurements. Our RMPS results agree well, qualitatively, with the experimental measurements, but there exist outstanding discrepancies to be addressed. This project is supported by NASA APRA award NNX17AD41G.
3. A single phosphorus treatment doubles growth of cyanobacterial lichen transplants.
Science.gov (United States)
McCune, Bruce; Caldwell, Bruce A
2009-02-01
Lichens are reputedly slow growing and become unhealthy or die in response to supplements of the usual limiting resources, such as water and nitrogen. We found, however, that the tripartite cyanobacterial lichen Lobaria pulmonaria doubled in annual biomass growth after a single 20-minute immersion in a phosphorus solution (K2HPO4), as compared to controls receiving no supplemental phosphorus. This stimulation of cyanolichens by phosphorus has direct relevance to community and population ecology of lichens, including improving models of lichen performance in relation to air quality, improving forest management practices affecting old-growth associated cyanolichens, and understanding the distribution and abundance of cyanolichens on the landscape. Phosphorus may be as important a stimulant to cyanobacterial-rich lichen communities as it is to cyanobacteria in aquatic ecosystems.
4. Single and double ionization of gallium by electron impact
It is concluded that the ionization of 3d shell contributes partly to single ionization and partly to double ionization. The results so obtained show reasonably good agreement with the experimental data. Author Affiliations. L K Jha1. Department of Physics, L N T College, Muzaffarpur 842 002, India. Dates. Manuscript received ...
5. Ionization dual-zone static detector having single radioactive source
International Nuclear Information System (INIS)
1977-01-01
This ionization detector or combustion product detector includes a single radioactive source located in an ionization chamber, and the ionization chamber includes portions comprising a reference zone and a signal zone. Electrical circuitry connected to the reference and signal zones provides an output signal directly related to changes in voltages across the signal zone in relation to the amount of particulates of combustion present in the ionization chamber
6. Time expansion chamber and single ionization cluster measurement
International Nuclear Information System (INIS)
Walenta, A.H.
1978-10-01
The time expansion chamber (TEC), a new type of drift chamber, allows the measurement of microscopic details of ionization. The mean drift time interval from subsequent sngle ionization clusters of a relativistic particle in the TEC can be made large enough compared to the width of a anode signal to allow the recording of the clusters separately. Since single primary electrons can be detected, the cluster counting would allow an improved particle separation using the relativistic rise of primary ionization. In another application, very high position accuracy for track detectors or improved energy resolution may be obtained. Basic ionization phenomena and drift properties can be measured at the single electron level
7. Strength and Stability Analysis of a Single Walled Black Phosphorus Tube under Axial Compression
OpenAIRE
Cai, Kun; Wan, Jing; Wei, Ning; Qin, Qinghua
2016-01-01
Few-layered black phosphorus materials recently attract much attention due to its special electronic properties. As a Consequence, the nano-tube from a single-layer black phosphorus has been theoretically built. The corresponding electronic properties of such black phosphorus nano-tube were also evaluated numerically.
8. Single and double ionization of gallium by electron impact
case of electron impact single ionization of In·. In order to obtain satisfactory agree- ment with experimental data, the contribution of the electrons of 4d shells to the ionization cross sections was added at only one half of its calculated value. Use of only half of the d-shell contributions was first proposed by Rogers et al [8] and ...
9. Molecular single photon double K-shell ionization
International Nuclear Information System (INIS)
Penent, F.; Nakano, M.; Tashiro, M.; Grozdanov, T.P.; Žitnik, M.; Carniato, S.; Selles, P.; Andric, L.; Lablanquie, P.; Palaudoux, J.; Shigemasa, E.; Iwayama, H.; Hikosaka, Y.; Soejima, K.; Suzuki, I.H.; Kouchi, N.; Ito, K.
2014-01-01
We have studied single photon double K-shell ionization of small molecules (N 2 , CO, C 2 H 2n (n = 1–3), …) and the Auger decay of the resulting double core hole (DCH) molecular ions thanks to multi-electron coincidence spectroscopy using a magnetic bottle time-of-flight spectrometer. The relative cross-sections for single-site (K −2 ) and two-site (K −1 K −1 ) double K-shell ionization with respect to single K-shell (K −1 ) ionization have been measured that gives important information on the mechanisms of single photon double ionization. The spectroscopy of two-site (K −1 K −1 ) DCH states in the C 2 H 2n (n = 1–3) series shows important chemical shifts due to a strong dependence on the C-C bond length. In addition, the complete cascade Auger decay following single site (K −2 ) ionization has been obtained
10. Single and double ionization of gallium by electron impact
theoretical methods. They stated that the available published data were slightly contra- dictory and according to Kozlov [6], a large number of 3d 94s24p terms are .... brief outline of the method of calculation is given below. ..... ing qualitative features of contribution of 3d shell to single and double ionization cross sections.
11. Intrinsic Charge Carrier Mobility in Single-Layer Black Phosphorus.
Science.gov (United States)
Rudenko, A N; Brener, S; Katsnelson, M I
2016-06-17
We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13} cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (μ_{xx}/μ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300 K), the electron mobility is found to be significantly more anisotropic (μ_{xx}/μ_{yy}∼6.2). Absolute values of μ_{xx} do not exceed 250 (700) cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature.
12. Single Pixel Black Phosphorus Photodetector for Near-Infrared Imaging.
Science.gov (United States)
Miao, Jinshui; Song, Bo; Xu, Zhihao; Cai, Le; Zhang, Suoming; Dong, Lixin; Wang, Chuan
2018-01-01
Infrared imaging systems have wide range of military or civil applications and 2D nanomaterials have recently emerged as potential sensing materials that may outperform conventional ones such as HgCdTe, InGaAs, and InSb. As an example, 2D black phosphorus (BP) thin film has a thickness-dependent direct bandgap with low shot noise and noncryogenic operation for visible to mid-infrared photodetection. In this paper, the use of a single-pixel photodetector made with few-layer BP thin film for near-infrared imaging applications is demonstrated. The imaging is achieved by combining the photodetector with a digital micromirror device to encode and subsequently reconstruct the image based on compressive sensing algorithm. Stationary images of a near-infrared laser spot (λ = 830 nm) with up to 64 × 64 pixels are captured using this single-pixel BP camera with 2000 times of measurements, which is only half of the total number of pixels. The imaging platform demonstrated in this work circumvents the grand challenges of scalable BP material growth for photodetector array fabrication and shows the efficacy of utilizing the outstanding performance of BP photodetector for future high-speed infrared camera applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
13. An atomic model for neutral and singly ionized uranium
Science.gov (United States)
Maceda, E. L.; Miley, G. H.
1979-01-01
A model for the atomic levels above ground state in neutral, U(0), and singly ionized, U(+), uranium is described based on identified atomic transitions. Some 168 states in U(0) and 95 in U(+) are found. A total of 1581 atomic transitions are used to complete this process. Also discussed are the atomic inverse lifetimes and line widths for the radiative transitions as well as the electron collisional cross sections.
14. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer
Directory of Open Access Journals (Sweden)
Yunguang Huang
2015-01-01
Full Text Available A vacuum ultraviolet lamp based single photon ionization- (SPI- photoelectron ionization (PEI portable reflecting time-of-flight mass spectrometer (TOFMS was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX, SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1 with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.
15. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer
Science.gov (United States)
Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang
2015-01-01
A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023
16. Detection of single atoms by resonance ionization spectroscopy
International Nuclear Information System (INIS)
Hurst, G.S.
1986-01-01
Rutherford's idea for counting individual atoms can, in principle, be implemented for nearly any type of atom, whether stable or radioactive, by using methods of resonance ionization. With the RIS technique, a laser is tuned to a wavelength which will promote a valence electron in a Z-selected atom to an excited level. Additional resonance or nonresonance photoabsorption steps are used to achieve nearly 100% ionization efficiencies. Hence, the RIS process can be saturated for the Z-selected atoms; and since detectors are available for counting either single electrons or positive ions, one-atom detection is possible. Some examples are given of one-atom detection, including that of the noble gases, in order to show complementarity with AMS methods. For instance, the detection of 81 Kr using RIS has interesting applications for solar neutrino research, ice-cap dating, and groundwater dating. 39 refs., 7 figs., 2 tabs
17. Single-walled carbon nanotubes as stabilizing agents in red phosphorus Li-ion battery anodes
KAUST Repository
Smajic, Jasmin
2017-08-16
Phosphorus boasts extremely high gravimetric and volumetric capacities but suffers from poor electrochemical stability with significant capacity loss immediately after the first cycle. We propose to circumvent this issue by mixing amorphous red phosphorus with single-walled carbon nanotubes. Employing a non-destructive sublimation–deposition method, we have synthesized composites where the synergetic effect between red phosphorus and single-walled carbon nanotubes allows for a considerable improvement in the electrochemical stability of battery anodes. In contrast to the average 40% loss of capacity after 50 cycles for other phosphorus–carbon composites in the literature, our material shows losses of just 22% under analogous cycling conditions.
18. Auger transitions in singly and multiply ionized atoms
International Nuclear Information System (INIS)
Mehlhorn, W.
1978-01-01
Some recent progress in Auger and autoionizing electron spectrometry of free metal atoms and of multiply ionized atoms is reviewed. The differences which arise between the spectra of atoms in the gaseous and the solid state are due to solid state effects. This will be shown for Cd as an example. The super Coster-Kronig transitions 3p-3d 2 (hole notation) and Coster-Kronig transitions 3p-3d 4s have been measured and compared with free-atom calculations for free Zn atoms. The experimental width GAMMA(3p)=(2.1+-0.2)eV found for the free atom agrees with the value obtained for solid Zn but is considerably smaller than the theoretical value for the free atom. Autoionizing spectra of Na following an L-shell excitation or ionization by different particles are compared and discussed. The nonisotropic angular distribution of electrons from the transition 2p 5 3s 2 2 Psub(3/2)→2p 6 +e - is compared with theoretical calculations. Two examples for Auger spectrometry of multiply ionized atoms are given: (1) excitation of neon target atoms by light and heavy ions, and (2) excitation of projectile ions Be + and B + in single gas collisions with CH 4 . A strong alignment of the excited atoms has also been found here
19. Single ionization of helium by 730-eV electrons
International Nuclear Information System (INIS)
Stevenson, M. A.; Lohmann, B.; Bray, I.; Fursa, D. V.; Stelbovics, A. T.
2007-01-01
We present fully differential measurements of 730-eV electron-impact single ionization of the ground state of helium with 205- or 100-eV outgoing electrons. Internormalized data are obtained for coplanar geometries with the fast electron detected at θ A =6 degree sign , 9 degree sign , and 12 degree sign . The data are compared, where possible, with the corresponding data of Catoire et al. [J. Phys. B 39, 2827 (2006)] and the convergent close-coupling theory. An improved agreement is found between the present measurements and the theory
20. Quasi free mechanism in single photon double ionization of helium
Energy Technology Data Exchange (ETDEWEB)
Schoeffler, Markus; Stuck, Christian [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Lawrence Berkeley National Lab, Berkeley, CA (United States); Jahnke, Till; Waitz, Markus; Trinter, Florian; Lenz, Ute; Schmidt-Boecking, Horst; Doerner, Reinhard [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Jones, Mathew; Landers, Allen [Auburn University, Auburn, AL (United States); Belkacem, Ali; Weber, Thorsten [Lawrence Berkeley National Lab, Berkeley, CA (United States); Cocke, Lew [Kansas State University, Manhattan, KS (United States)
2012-07-01
Double ionization of Helium by a single photon is widely believed to proceed through two mechanisms: knock-off (TS1) or shake-off, with the last one dominating at high photon energies. A new mechanism, termed ''Quasi Free Mechanism'' (QFM) was predicted 35 years ago by Amusia and coworkers, but escaped experimental observation till today. Here we provide the first proof of this mechanism using 800 eV photons from the Advanced Light Source. Fragments (electrons and ions) were measured in coincidence using momentum spectroscopy (COLTRIMS). He{sup (}2+) ions with zero momentum were found - the fingerprint for the QFM.
1. Depolarizing collisions with hydrogen: Neutral and singly ionized alkaline earths
Energy Technology Data Exchange (ETDEWEB)
Manso Sainz, Rafael; Ramos, Andrés Asensio; Bueno, Javier Trujillo [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Roncero, Octavio; Sanz-Sanz, Cristina [Instituto de Física Fundamental (IFF-CSIC), CSIC, Serrano 123, E-28006 Madrid (Spain); Aguado, Alfredo, E-mail: [email protected] [Departamento de Química Física, Unidad Asociada UAM-CSIC, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, E-28049 Madrid (Spain)
2014-06-20
Depolarizing collisions are elastic or quasielastic collisions that equalize the populations and destroy the coherence between the magnetic sublevels of atomic levels. In astrophysical plasmas, the main depolarizing collider is neutral hydrogen. We consider depolarizing rates on the lowest levels of neutral and singly ionized alkali earths Mg I, Sr I, Ba I, Mg II, Ca II, and Ba II, due to collisions with H°. We compute ab initio potential curves of the atom-H° system and solve the quantum mechanical dynamics. From the scattering amplitudes, we calculate the depolarizing rates for Maxwellian distributions of colliders at temperatures T ≤ 10,000 K. A comparative analysis of our results and previous calculations in the literature is completed. We discuss the effect of these rates on the formation of scattering polarization patterns of resonant lines of alkali earths in the solar atmosphere, and their effect on Hanle effect diagnostics of solar magnetic fields.
2. Diverse and tunable electronic structures of single-layer metal phosphorus trichalcogenides for photocatalytic water splitting
International Nuclear Information System (INIS)
Liu, Jian; Li, Xi-Bo; Wang, Da; Liu, Li-Min; Lau, Woon-Ming; Peng, Ping
2014-01-01
The family of bulk metal phosphorus trichalcogenides (APX 3 , A = M II , M 0.5 I M 0.5 III ; X = S, Se; M I , M II , and M III represent Group-I, Group-II, and Group-III metals, respectively) has attracted great attentions because such materials not only own magnetic and ferroelectric properties, but also exhibit excellent properties in hydrogen storage and lithium battery because of the layered structures. Many layered materials have been exfoliated into two-dimensional (2D) materials, and they show distinct electronic properties compared with their bulks. Here we present a systematical study of single-layer metal phosphorus trichalcogenides by density functional theory calculations. The results show that the single layer metal phosphorus trichalcogenides have very low formation energies, which indicates that the exfoliation of single layer APX 3 should not be difficult. The family of single layer metal phosphorus trichalcogenides exhibits a large range of band gaps from 1.77 to 3.94 eV, and the electronic structures are greatly affected by the metal or the chalcogenide atoms. The calculated band edges of metal phosphorus trichalcogenides further reveal that single-layer ZnPSe 3 , CdPSe 3 , Ag 0.5 Sc 0.5 PSe 3 , and Ag 0.5 In 0.5 PX 3 (X = S and Se) have both suitable band gaps for visible-light driving and sufficient over-potentials for water splitting. More fascinatingly, single-layer Ag 0.5 Sc 0.5 PSe 3 is a direct band gap semiconductor, and the calculated optical absorption further convinces that such materials own outstanding properties for light absorption. Such results demonstrate that the single layer metal phosphorus trichalcogenides own high stability, versatile electronic properties, and high optical absorption, thus such materials have great chances to be high efficient photocatalysts for water-splitting
3. Ionizing radiation effect of phosphorus 32 on the bone marrow of hamsters
International Nuclear Information System (INIS)
Leite, J.B.F.; Marziona, F.
1980-01-01
105 hamsters were distributed in 3 groups: Group I with 5 animals, for control observations. Group II with 80 animals, which was injected with 1 milicurie of phosphorus 32 (0,12 ml of the solution) in only one dose, subperiosteum way, in the left femur. Group III with 20 animals was injected with 0,12 ml of phosphate's solution (substance without radioactivity) in only one dose, subperiosteum way, in the left femur. The animals were evaluated by the following parameters: clinical evaluation, macroscopy, optical microscopy of the femur, eletronic microscopy of the bone marrow and scintillographic captation of the femur, obtaining clinical, anatomopathologic and microscopic disturbances. (Author) [pt
4. Ionization in matrix-assisted laser desorption/ionization: singly charged molecular ions are the lucky survivors.
Science.gov (United States)
Karas, M; Glückmann, M; Schäfer, J
2000-01-01
A new model for the ionization processes in UV matrix-assisted laser desorption/ionization (MALDI) which accounts for the major phenomena observed is presented and discussed. The model retains elements of earlier approaches, such as photoionization and photochemical reactions, but it redefines these in the light of new working questions, most importantly why only singly charged ions are detected. Based on experimental evidence, the formation of singly and multiply charged clusters by a deficiency/excess of ions and also by photoionization and subsequent photochemical processes is pointed out to be the major ionization processes, which typically occur in parallel. The generation of electrons and their partial loss into the surrounding vacuum and solid, on the one hand, results in a positively charged ion-neutral plume facilitating a high overall ionization yield. On the other hand, these electrons, and also the large excess of protonated matrix ions in the negative ion mode, induce effective ion reneutralization in the plume. These neutralization processes are most effective for the highly charged cluster ions initially formed. Their fragmentation behaviour is evidenced in fast metastable fragmentation characteristics and agrees well with an electron capture dissociation mechanism and the enthalpy transfer upon neutralization forms the rationale for the prominent fragmentation and intense chemical noise accompanying successful MALDI. Within the course of the paper, cross-correlations with other desorption/ionization techniques and with earlier discussions on their mechanisms are drawn. Copyright 2000 John Wiley & Sons, Ltd.
5. Understanding single-color multiphoton ionization spectra by pump--probe technique
Energy Technology Data Exchange (ETDEWEB)
Dasgupta, K.; Manohar, K.G.; Bajaj, P.N.; Suri, B.M.; Talukdar, R.K.; Chakraborti, P.K.; Rao, P.R.K.
1988-06-01
A simple but elegant spectroscopic technique using two narrow-band dye lasers has been demonstrated for analyzing single-color resonant multi-photon-ionization spectra of atoms. This technique provides a direct identification of the starting level of the multi-photon-ionization pathway. This method can also be used to determine intermediate levels, which play an important role in the ionization process. Some typical results for uranium are presented.
6. Single- and Multiwalled Carbon Nanotubes with Phosphorus Based Flame Retardants for Textiles
OpenAIRE
D. Wesolek; W. Gieparda
2014-01-01
Due to growing popularity of composites, modification methods to obtain the best properties are searched for. The aim of the study is to reduce the flammability of textile materials using nanocomposite polymer back-coating. Different types of carbon nanotubes (single- and multiwalled) and different phosphorus flame retardants (ammonium polyphosphates and melamine polyphosphate) were introduced into the resin and then the fabrics were covered by the obtained composites. Homogeneous dispersion ...
7. Time delay between singly and doubly ionizing wavepackets in laser-driven helium
International Nuclear Information System (INIS)
Parker, J S; Doherty, B J S; Meharg, K J; Taylor, K T
2003-01-01
We present calculations of the time delay between single and double ionization of helium, obtained from full-dimensionality numerical integrations of the helium-laser Schroedinger equation. The notion of a quantum mechanical time delay is defined in terms of the interval between correlated bursts of single and double ionization. Calculations are performed at 390 and 780 nm in laser intensities that range from 2 x 10 14 to 14 x 10 14 Wcm -2 . We find results consistent with the rescattering model of double ionization but supporting its classical interpretation only at 780 nm. (letter to the editor)
8. First-principles study of thermal expansion and thermomechanics of single-layer black and blue phosphorus
International Nuclear Information System (INIS)
Sun, Hongyi; Liu, Gang; Li, Qingfang; Wan, X.G.
2016-01-01
The linear thermal expansion coefficients (LTEC) and thermomechanics of single-layer black and blue phosphorus are systematically studied using first-principles based on quasiharmonic approximation. We find the thermal expansion of black phosphorus is very anisotropic. The LTEC along zigzag direction has a turning from negative to positive at around 138 K, while the LTEC along armchair direction is positive (except below 8 K) and about 2.5 times larger than that along zigzag direction at 300 K. For blue phosphorus, the LTEC is negative in the temperature range from 0 to 350 K. In addition, we find that the Young's modulus and Poisson's ratio of black phosphorus along zigzag direction are 4 to 5 times larger than those along armchair direction within considered temperature range, showing a remarkable anisotropic in-plane thermomechanics property. The mechanisms of these peculiar thermal properties are also explored. This work provides a theoretical understanding of the thermal expansion and thermomechanics of this single layer phosphorus family, which will be useful in nanodevices. - Highlights: • The thermal properties of black and blue phosphorus are studied. • Black phosphorus shows remarkable anisotropic thermal expansion and thermomechanics properties. • Blue phosphorus shows novel negative thermal expansion. • The thermal expansion properties are well analyzed by grüneisen theory.
9. The spectrum of singly ionized yttrium, Y II
International Nuclear Information System (INIS)
Nilsson, A.E.; Johansson, S.; Kurucz, R.L.
1991-01-01
Hollow-cathode spectra of yttrium have been registered in the wavelength region 1000-48800 A. Resonant charge transfer reactions in the light source favour the excitation of Y II, where 174 new levels have been established by means of 1284 newly classified lines. Altogether we report 1521 lines between 235 levels in Y II. The ground complex (4d+5s) 2 is now completely known and a number of Rydberg series have been extended. The new levels belong to the 4dnl (nl=7s, 8s, 9s, 6p, 7p, 4d, 5d, 6d, 7d, 8d, 4f, 5f, 6f, 7f, 5g) and 5snl (nl=7s, 8s, 6p, 6d, 4f, 5f) configurations. Eigenvector compositions, based on paramagnetic calculations including configuration interaction, are given for all levels. The ionization limit has been determined to 98590 ± 5 cm -1 . (orig.)
10. Single- and multi-photon ionization studies of organosulfur species
Energy Technology Data Exchange (ETDEWEB)
Cheung, Yu -San [Iowa State Univ., Ames, IA (United States)
1999-02-12
Accurate ionization energies (IE`s) for molecular species are used for prediction of chemical reactivity and are of fundamental importance to chemists. The IE of a gaseous molecule can be determined routinely in a photoionization or a photoelectron experiment. IE determinations made in conventional photoionization and photoelectron studies have uncertainties in the range of 3--100 meV (25--250 cm-1). In the past decade, the most exciting development in the field of photoionization and photoelectron spectroscopy has been the availability of high resolution, tunable ultraviolet (UV) and vacuum ultraviolet (VUV) laser sources. The laser pulsed field ionization photoelectron (PFI-PE) scheme is currently the state-of-the-art photoelectron spectroscopic technique and is capable of providing photoelectron energy resolution close to the optical resolution. The author has focused attention on the photoionization processes of some sulfur-containing species. The studies of the photoionization and photodissociation on sulfur-containing compounds [such as CS2, CH3SH, CH3SSCH3, CH3CH2SCH2CH3, HSCH2CH2SH and C4H4S (thiophene) and sulfur-containing radicals, such as HS, CS, CH3S, CH3CH2S and CH3SS], have been the major subjects in the group because sulfur is an important species contributing to air pollution in the atmosphere. The modeling of the combustion and oxidation of sulfur compounds represents important steps for the control of both the production and the elimination of sulfur-containing pollutants. Chapter 1 is a general introduction of the thesis. Chapters 2 and 6 contain five papers published in, or accepted for publication in, academic periodicals. In Chapter 7, the progress of the construction in the laboratory of a new vacuum ultraviolet laser system equipped with a reflectron mass
11. Momentum spectra for single and double electron ionization of He in relativistic collisions
International Nuclear Information System (INIS)
Wood, C.J.; Olson, R.E.
1997-08-01
The complete momentum spectra for single and double ionization of He by 1GeV/u (β=0.88) U 92+ have been investigated using a classical trajectory Monte Carlo method corrected for the relativistic projectile. The 1/r 12 electron-electron interaction has been included in the post-collision region for double ionization to incorporate the effects of both the nuclear-electron and electron-electron ionizing interactions, and to access the effects of electron correlation in the electron spectra. Experimental measurements were able to determine the longitudinal momentum spectra for single ionization; these observations are in accordance with the theoretical predictions for the three-body momentum balance between projectile, recoil ion, and ionized electron. In particular, the Lorentz contraction of the Coulomb interaction of the projectile manifests itself in the decrease of the post-collision interaction of the projectile with the electron and recoil ion, causing them to recoil back-to-back as in the case for a short electromagnetic pulse. This feature is clearly displayed in both the theoretical and experimental longitudinal momentum spectra, and by comparing to calculations that are performed at the same collision speed but do not include the relativistic potentials. Moreover, collision plane spectra of the three particles demonstrate that the momenta of the recoil ion and ionized electron are preferentially equal, and opposite, to each other. The electron spectra for double ionization show that the inclusion of the electron-electron interaction in the post-collision regime partitions the combined ionization momentum of the electrons so that the electrons are preferentially emitted in opposite azimuthal angles to one another. This is in contrast to calculations made assuming independent electrons. (orig.)
12. Formation of molecules in interstellar clouds from singly and multiply ionized atoms
International Nuclear Information System (INIS)
Langer, W.D.; and NASA, Institute for Space Studies, Goddard Space Flight Center, New York)
1978-01-01
Soft X-ray and cosmic rays produce multiply ionized atoms which may initiate molecule production in interstellar clouds. This molecule production can occur via ion-molecule reactions with H 2 , either directly from the multiply ionized atom (e.g.,C ++ + H 2 →CH + + H + ), or indirectly from the singly ionized atoms (e.g., N + + H 2 →NH + + H) that are formed from the recombination or charge transfer of the highly ionized atom (e.g., N ++ + e→N + + hv). We investigate the contribution of these reactions to the abundances of carbon-, nitrogen-, and oxygen-bearing molecules in isobaric models of diffuse clouds. In the presence of the average flux estimated for the diffuse soft X-ray background, multiply ionized atoms contribute only minimally (a few percent) to carbon-bearing molecules such as CH. In the neighborhood of diffuse structures or discrete sources, however, where the X-ray flux is enhanced, multiple ionization is considerably more important for molecule production
13. Thermal vibration of rectangular single-layered black phosphorus predicted by orthotropic plate model
Science.gov (United States)
Zhang, Yiqing; Wang, Lifeng; Jiang, Jingnong
2018-03-01
Vibrational behavior is very important for nanostructure-based resonators. In this work, an orthotropic plate model together with a molecular dynamics (MD) simulation is used to investigate the thermal vibration of rectangular single-layered black phosphorus (SLBP). Two bending stiffness, two Poisson's ratios, and one shear modulus of SLBP are calculated using the MD simulation. The natural frequency of the SLBP predicted by the orthotropic plate model agrees with the one obtained from the MD simulation very well. The root of mean squared (RMS) amplitude of the SLBP is obtained by MD simulation and the orthotropic plate model considering the law of energy equipartition. The RMS amplitude of the thermal vibration of the SLBP is predicted well by the orthotropic plate model compared to the MD results. Furthermore, the thermal vibration of the SLBP with an initial stress is also well-described by the orthotropic plate model.
14. Effect of giant plasmon excitations in single and double ionization of C60 in fast heavy-ion collisions
Science.gov (United States)
Kadhane, Umesh; Kelkar, A.; Misra, D.; Kumar, Ajay; Tribedi, Lokesh C.
2007-04-01
Single and multiple ionization of C60 in collisions with highly charged fast oxygen ions have been studied using the recoil-ion time-of-flight technique. The dependence of multiple-ionization cross sections on projectile charge state (qp) was found to be drastically different from those for an atomic target, such as Ne. A model based on the giant dipole plasmon resonance explains quite well the observed qp dependence for the single- and-double-ionization cross sections. But the same model deviates for triple and quadruple ionizations.
15. Single-Particle Time-of-Flight Mass Spectrometry Utilizing a Femtosecond Desorption and Ionization Laser.
Science.gov (United States)
Zawadowicz, Maria A; Abdelmonem, Ahmed; Mohr, Claudia; Saathoff, Harald; Froyd, Karl D; Murphy, Daniel M; Leisner, Thomas; Cziczo, Daniel J
2015-12-15
Single-particle time-of-flight mass spectrometry has now been used since the 1990s to determine particle-to-particle variability and internal mixing state. Instruments commonly use 193 nm excimer or 266 nm frequency-quadrupled Nd:YAG lasers to ablate and ionize particles in a single step. We describe the use of a femtosecond laser system (800 nm wavelength, 100 fs pulse duration) in combination with an existing single-particle time-of-flight mass spectrometer. The goal of this project was to determine the suitability of a femtosecond laser for single-particle studies via direct comparison to the excimer laser (193 nm wavelength, ∼10 ns pulse duration) usually used with the instrument. Laser power, frequency, and polarization were varied to determine the effect on mass spectra. Atmospherically relevant materials that are often used in laboratory studies, ammonium nitrate and sodium chloride, were used for the aerosol. Detection of trace amounts of a heavy metal, lead, in an ammonium nitrate matrix was also investigated. The femtosecond ionization had a large air background not present with the 193 nm excimer and produced more multiply charged ions. Overall, we find that femtosecond laser ablation and ionization of aerosol particles is not radically different than that provided by a 193 nm excimer.
16. Coupled Cluster Studies of Ionization Potentials and Electron Affinities of Single-Walled Carbon Nanotubes
Energy Technology Data Exchange (ETDEWEB)
Peng, Bo; Govind, Niranjan; Apra, Edoardo; Klemm, Michael; Hammond, Jeff R.; Kowalski, Karol
2017-02-03
In this paper we apply equation-of-motion coupled cluster (EOMCC) methods in studies of vertical ionization potentials (IP) and electron affinities (EA) for sin- gled walled carbon nanotubes. EOMCC formulations for ionization potentials and electron affinities employing excitation manifolds spanned by single and double ex- citations (IP/EA-EOMCCSD) are used to study IPs and EAs of nanotubes as a function of nanotube length. Several armchair nanotubes corresponding to C20nH20 models with n = 2 - 6 have been used in benchmark calculations. In agreement with previous studies, we demonstrate that the electronegativity of C20nH20 systems remains, to a large extent, independent of nanotube length. We also compare IP/EA- EOMCCSD results with those obtained with the coupled cluster models with single and double excitations corrected by perturbative triples, CCSD(T), and density func- tional theory (DFT) using global and range-separated hybrid exchange-correlation functionals.
17. Double and single ionization of helium by 58-keV X-rays
International Nuclear Information System (INIS)
Spielberger, L.; Buslaps, T.; Braeuning, H.; Gemmell, D.S.; Schmidt-Boecking, H.
1996-03-01
We have measured the ratio of cross sections for double to single ionization of helium by Compton scattering, R c =σ c ++ /σ c + at a photon energy of 58 keV using Cold Target Recoil Ion Momentum Spectroscopy. We find a value R c =(0.84 -11 +08 )% that is in agreement with the asymptotic limits predicted by Andersson and Burgdoerfer (Phys. Rev. A 50, R2810 (1994)) and Suric et al. (Phys. Rev. Lett. 73, 790 (1994)). (orig.)
18. Ionization of elements in medium power capacitively coupled argon plasma torch with single and double ring electrodes.
Science.gov (United States)
Ponta, Michaela; Frentiu, Maria; Frentiu, Tiberiu
2012-06-01
A medium power, low Ar consumption capacitively coupled plasma torch (275 W, 0.4 L min-1) with molybdenum tubular electrode and single or two ring electrodes in non-local thermodynamic equilibrium (LTE) was characterized with respect to its ability to achieve element ionization. Ionization degrees of Ca, Mg, Mn and Cd were determined from ionic-to-atomic emission ratio and ionization equilibrium according to Saha's equation. The ionization degrees resulted from the Saha equation were higher by 9-32% than those obtained from spectral lines intensity in LTE regime and closer to reality. A linear decrease of ionization with increase of ionization energy of elements was observed. Plasma torch with two ring electrodes provided higher ionization degrees (85 ± 7% Ca, 79 ± 7% Mn, 80 ± 7% Mg and 73 ± 8% Cd) than those in single ring arrangement (70 ± 6% Ca, 57 ± 7% Mn, 57 ± 8% Mg and 42 ± 9% Cd). The Ca ionization decreased linearly by up to 79 ± 4% and 53 ± 6% in plasma with two ring electrodes and single ring respectively in the presence of up to 400 µg mL-1 Na as interferent. The studied plasma was effective in element ionization and could be a potential ion source in mass spectrometry.
19. Fast detection of narcotics by single photon ionization mass spectrometry and laser ion mobility spectrometry
Science.gov (United States)
Laudien, Robert; Schultze, Rainer; Wieser, Jochen
2010-10-01
In this contribution two analytical devices for the fast detection of security-relevant substances like narcotics and explosives are presented. One system is based on an ion trap mass spectrometer (ITMS) with single photon ionization (SPI). This soft ionization technique, unlike electron impact ionization (EI), reduces unwanted fragment ions in the mass spectra allowing the clear determination of characteristic (usually molecular) ions. Their enrichment in the ion trap and identification by tandem MS investigations (MS/MS) enables the detection of the target substances in complex matrices at low concentrations without time-consuming sample preparation. For SPI an electron beam pumped excimer light source of own fabrication (E-Lux) is used. The SPI-ITMS system was characterized by the analytical study of different drugs like cannabis, heroin, cocaine, amphetamines, and some precursors. Additionally, it was successfully tested on-site in a closed illegal drug laboratory, where low quantities of MDMA could be directly detected in samples from floors, walls and lab equipments. The second analytical system is based on an ion mobility (IM) spectrometer with resonant multiphoton ionization (REMPI). With the frequency quadrupled Nd:YAG laser (266 nm), used for ionization, a selective and sensitive detection of aromatic compounds is possible. By application of suited aromatic dopants, in addition, also non-aromatic polar compounds are accessible by ion molecule reactions like proton transfer or complex formation. Selected drug precursors could be successfully detected with this device as well, qualifying it to a lower-priced alternative or useful supplement of the SPI-ITMS system for security analysis.
20. Threshold behavior in single-photon double ionization of atomic oxygen
Science.gov (United States)
He, Z. X.; Moberg, R.; Samson, J. A. R.
1995-12-01
The threshold behavior of the single-photon double-ionization cross section of atomic oxygen has been studied using vacuum uv radiation from a synchrotron storage ring. The double-ionization cross section appears to follow a power law Eα (where E is the kinetic energy of the two electrons) from its threshold to about 2.0 eV above with an exponent α=1.08+/-0.03, which is consistent with Wannier's theoretical value of 1.056. The cross section also shows the influence of the doubly excited 2s2p3nln'l' (n,n'>~3) neutral states, among which the first three converge to the 2s2p3(5So)4p(6Po) ionic state of oxygen.
1. Single- and Multiwalled Carbon Nanotubes with Phosphorus Based Flame Retardants for Textiles
Directory of Open Access Journals (Sweden)
D. Wesolek
2014-01-01
Full Text Available Due to growing popularity of composites, modification methods to obtain the best properties are searched for. The aim of the study is to reduce the flammability of textile materials using nanocomposite polymer back-coating. Different types of carbon nanotubes (single- and multiwalled and different phosphorus flame retardants (ammonium polyphosphates and melamine polyphosphate were introduced into the resin and then the fabrics were covered by the obtained composites. Homogeneous dispersion of multiwalled carbon nanotubes in the polyurethane resin was obtained by sonification, which was confirmed by scanning electron microscopy. Flammability tests of fabrics coated by modified polyurethane resin were carried out using pyrolysis combustion flow calorimeter (PCFC and thermal stability of textiles was evaluated. Also, organoleptic estimation of coatings was conducted (flexibility and fragility. The use of polymer nanocomposites with phophorus flame retardants as a back-coating for textiles effectively reduces flammability and improves thermal stability of the fabric. Furthermore, the synergistic effect beetwen carbon nanotubes and phosphorous compound occurs. The resulting coatings are flexible and do not crack or change the feel of fabrics.
2. Meas.of the Ratio Between Double and Single Ionization of Helium for Antiprotons
CERN Multimedia
2002-01-01
The aim of this experiment is to measure the ratio between double and single ionization of helium by antiprotons in the energy range $>$~3~MeV. Comparison with already existing proton data will yield information on the mechanisms for double ionization, which could not be extracted from previous comparisons between ratios measured for equivelocity electrons and protons. The most basic information to be obtained from an antiproton experiment will be the amount of correlation existing between the two electrons in the ground-state helium atom.\\\\ \\\\ The equipment consists of a gas cell, which employs slow-ion collection via the so-called condenser-plate method for the absolute sum of partial-ionization cross sections and determination of the relative contribution of multiple charged ions by TOF. The gas cell has movable entrance and exit slits and a grid system to account for secondary emission from the collection of slow ions. Together with a field of 800~V/cm in the collision region, the potentials of the TOF sp...
3. Comprehensive Wavelengths, Energy Levels, and Hyperfine Structure Parameters of Singly-Ionized Iron-Group Elements
Science.gov (United States)
Nave, Gillian
We propose to measure wavelengths, energy levels, and hyperfine structure parameters of Ni II, Mn II, Sc II and other singly-ionized iron-group elements, covering the wavelength range 80 nm to 5500 nm. We shall use archival data from spectrometers at NIST and Kitt Peak National Observatory for spectra above 140 nm. Additional experimental observations will be taken if needed using Fourier transform spectrometers at NIST. Spectra will be taken using our normal incidence grating spectrograph to provide better sensitivity than the FT spectra and to extend the wavelength range down to 80 nm. We aim to produce a comprehensive description of the spectra of all singly-ionized iron- group elements. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. For most singly-ionized iron-group elements available laboratory data have uncertainties an order of magnitude larger than astronomical observations over wide spectra ranges. Some of these laboratory measurements date back to the 1960's. Since then, Fourier transform spectroscopy has made significant progress in improving the accuracy and quantity of data in the UV-vis-IR region, but high quality Fourier transform spectra are still needed for Mn II, Ni II and Sc II. Fourier transform spectroscopy has low sensitivity in the VUV region and is limited to wavelengths above 140 nm. Spectra measured with high-resolution grating spectrographs are needed in this region in order to obtain laboratory data of comparable quality to the STIS and COS spectrographs on the Hubble Space Telescope. Currently, such data exist only for Fe II and Cr II. Lines of Sc II, V II, and Mn II show hyperfine structure, but hyperfine structure parameters have been measured for relatively few lines of these elements. Significant errors can occur if hyperfine structure is neglected when abundances are determined from stellar spectra. Measurements of hyperfine structure parameters will be made using Fourier transform spectroscopy
4. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions
International Nuclear Information System (INIS)
Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C
2007-01-01
We have investigated the single and multiple ionizations of the C 60 molecule in collisions with fast Si q+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process
5. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions
Science.gov (United States)
Kelkar, A. H.; Kadhane, U.; Misra, D.; Kumar, A.; Tribedi, L. C.
2007-06-01
We have investigated the single and multiple ionizations of the C60 molecule in collisions with fast Siq+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.
6. Effect of multiple plasmon excitation on single, double and multiple ionizations of C{sub 60} in collisions with fast highly charged Si ions
Energy Technology Data Exchange (ETDEWEB)
Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)
2007-06-28
We have investigated the single and multiple ionizations of the C{sub 60} molecule in collisions with fast Si{sup q+} projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.
7. Quantum Monte Carlo Studies of Bulk and Few- or Single-Layer Black Phosphorus
Science.gov (United States)
Shulenburger, Luke; Baczewski, Andrew; Zhu, Zhen; Guan, Jie; Tomanek, David
2015-03-01
The electronic and optical properties of phosphorus depend strongly on the structural properties of the material. Given the limited experimental information on the structure of phosphorene, it is natural to turn to electronic structure calculations to provide this information. Unfortunately, given phosphorus' propensity to form layered structures bound by van der Waals interactions, standard density functional theory methods provide results of uncertain accuracy. Recently, it has been demonstrated that Quantum Monte Carlo (QMC) methods achieve high accuracy when applied to solids in which van der Waals forces play a significant role. In this talk, we will present QMC results from our recent calculations on black phosphorus, focusing on the structural and energetic properties of monolayers, bilayers and bulk structures. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under Contract DE-AC04-94AL85000.
8. Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro
Energy Technology Data Exchange (ETDEWEB)
Matthews, Q; Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Brolo, AG [Department of Chemistry, University of Victoria, Victoria BC V8W 3V6 (Canada); Lum, J; Duan, X, E-mail: [email protected], E-mail: [email protected] [Deeley Research Centre, BC Cancer Agency-Vancouver Island Centre, Victoria BC V8R 6V5 (Canada)
2011-01-07
9. A laser desorption-electron impact ionization ion trap mass spectrometer for real-time analysis of single atmospheric particles
Science.gov (United States)
Simpson, E. A.; Campuzano-Jost, P.; Hanna, S. J.; Robb, D. B.; Hepburn, J. H.; Blades, M. W.; Bertram, A. K.
2009-04-01
A novel aerosol ion trap mass spectrometer combining pulsed IR laser desorption with electron impact (EI) ionization for single particle studies is described. The strengths of this instrument include a two-step desorption and ionization process to minimize matrix effects; electron impact ionization, a universal and well-characterized ionization technique; vaporization and ionization inside the ion trap to improve sensitivity; and an ion trap mass spectrometer for MSn experiments. The instrument has been used for mass spectral identification of laboratory generated pure aerosols in the 600 nm-1.1 [mu]m geometric diameter range of a variety of aromatic and aliphatic compounds, as well as for tandem mass spectrometry studies (up to MS3) of single caffeine particles. We investigate the effect of various operational parameters on the mass spectrum and fragmentation patterns. The single particle detection limit of the instrument was found to be a 325 nm geometric diameter particle (8.7 × 107 molecules or 22 fg) for 2,4-dihydroxybenzoic acid. Lower single particle detection limits are predicted to be attainable by modifying the EI pulse. The use of laser desorption-electron impact (LD-EI) in an ion trap is a promising technique for determining the size and chemical composition of single aerosol particles in real time.
10. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions
Science.gov (United States)
Kelkar, A. H.; Kadhane, U.; Misra, D.; Tribedi, L. C.
2007-09-01
Se have investigated single and double ionization of C60 molecule in collisions with 2.33 MeV/u Siq+ (q=6-14) and 3.125 MeV/u Oq+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.
11. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions
International Nuclear Information System (INIS)
Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C
2007-01-01
Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening
12. Kinematically complete investigation of momentum transfer for single ionization in fast proton-helium collisions
Energy Technology Data Exchange (ETDEWEB)
Weber, T.; Mergel, V.; Jagutzki, O.; Schmidt, L.; Afaneh, F.; Schmidt-Boecking, H. [Institut fuer Kernphysik, August-Euler-Strasse 6, 60486 Frankfurt am Main (Germany); Khayyat, K. [Department of Physics, University of Missouri, Rolla, MO (United States); Doerner, R. [Fakultaet fuer Physik, Universitaet Freiburg (Germany); Gonzalez, A. [Centro Atomico Bariloche, 8400 S C de Bariloche (Argentina); Cocke, C.L. [Department of Physics, Kansas State University, Manhatten, KS (United States); Landers, A.L. [Department of Physics, Western Michigan University, Kalamazoo, MI (United States)
2000-09-14
The dynamics of singly ionizing proton-helium collisions have been studied experimentally for several energies of the projectile (0.2, 0.5, 1.0 and 1.3 MeV) with the technique of cold target recoil-ion momentum spectroscopy (COLTRIMS). The complete final-state distribution in momentum space of all three particles was determined by measuring the three momentum components of the emitted electron and the coincident recoiling target ion. The momentum transfer and energy loss of the outgoing projectile was determined by momentum and energy conservation laws. Doubly differential cross sections of the kinematically complete experimental investigation are presented. The present data are compared with results from fast highly charged heavy-ion impact experiments. (author)
13. Analysis of laser-generated plasma ionizing radiation by synthetic single crystal diamond detectors
Czech Academy of Sciences Publication Activity Database
Marinelli, M.; Milani, E.; Prestopino, G.; Verona, C.; Verona-Rinati, G.; Cutroneo, M.; Torrisi, L.; Margarone, Daniele; Velyhan, Andriy; Krása, Josef; Krouský, Eduard
2013-01-01
Roč. 272, May (2013), s. 104-108 ISSN 0169-4332 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087; GA MŠk(CZ) 7E09092; GA MŠk(CZ) LC528 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; 7FP LASERLAB-EUROPE(XE) 228334 Program:EE; FP7 Institutional support: RVO:68378271 Keywords : single crystal diamond * diamond detector * laser-generated plasma * ionizing radiation * time-of-fight spectrometer Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.538, year: 2013
14. The spectroscopy of the neutral and singly ionized transuranium elements, Np to Es
International Nuclear Information System (INIS)
Worden, E.F.
1990-01-01
This presentation will be a review of the optical spectroscopy of the neutral and singly ionized species of the elements Np through Es, the I and II spectra. Observation and energy level analyses of these spectra have been in progress for each element as soon as sufficient quantities were produced. A list of the researchers would exceed the allowed abstract length. Procedures for obtaining spectra of these highly radioactive elements and for energy level analysis will be described. The chemistry of these elements is usually well established before there is a substantial knowledge of the electronic structure. The regularities found in the electronic structure of the 5f actinide series will be shown and compared with that of the 4f lanthanide series. Some discussion of the structure as it relates to the chemistry of the transuranic elements will be given
15. Anisotropic Young's Modulus for Single-Layer Black Phosphorus: The Third Principle Direction Besides Armchair and Zigzag
OpenAIRE
Jiang, Jin-Wu
2015-01-01
We derive an analytic formula for the Young's modulus in single-layer black phosphorus using the valence force field model. By analyzing the directional dependence for the Young's modulus, we explore the third principle direction with direction angle phi_tp = 0.268pi besides armchair and zigzag directions. The maximum Young's modulus value is in the third principle direction. More specifically, the Young's modulus is 52.2 N/m, 85.4 N/m, and 111.4 N/m in the armchair direction, zigzag directio...
16. A practical theoretical formalism for atomic multielectron processes: direct multiple ionization by a single auger decay or by impact of a single electron or photon
Science.gov (United States)
Liu, Pengfei; Zeng, Jiaolong; Yuan, Jianmin
2018-04-01
Multiple electron processes occur widely in atoms, molecules, clusters, and condensed matters when they are interacting with energetic particles or intense laser fields. Direct multielectron processes (DMEP) are the most complicated among the general multiple electron processes and are the most difficult to describe theoretically. In this work, a unified and accurate theoretical formalism is proposed on the DMEP of atoms including the multiple auger decay and multiple ionization by an impact of a single electron or a single photon based on the atomic collision theory described by a correlated many-body Green's function. Such a practical treatment is made possible by taking consideration of the different coherence features of the atoms (matter waves) in the initial and final states. We first explain how the coherence characteristics of the ejected continuum electrons is largely destructed, by taking the electron impact direct double ionization process as an example. The direct double ionization process is completely different from the single ionization where the complete interference can be maintained. The detailed expressions are obtained for the energy correlations among the continuum electrons and energy resolved differential and integral cross sections according to the separation of knock-out (KO) and shake-off (SO) mechanisms for the electron impact direct double ionization, direct double and triple auger decay, and double and triple photoionization (TPI) processes. Extension to higher order DMEP than triple ionization is straight forward by adding contributions of the following KO and SO processes. The approach is applied to investigate the electron impact double ionization processes of C+, N+, and O+, the direct double and triple auger decay of the K-shell excited states of C+ 1s2{s}22{p}2{}2D and {}2P, and the double and TPI of lithium. Comparisons with the experimental and other theoretical investigations wherever available in the literature show that our
17. Total and single differential cross sections for the electron impact ionization of the ground state of helium
International Nuclear Information System (INIS)
Singh, T.S.C.; Choudhury, K.B.; Singh, M.B.; Deb, N.C.; Mukherjee, S.C.; Mazumdar, P.S.
1997-01-01
Total cross sections (TCS) and single differential cross sections (SDCS) have been computed for the single ionization of the ground state of helium by electron impact in a distorted wave formalism which takes into account the effects of the initial and final channel distortions. The present TCS and SDCS results are in fair agreement with the measured values and other theoretical predictions for the incident electron energy E i > 150 eV. (orig.)
18. Fully differential single-photon double ionization of neon and argon
Science.gov (United States)
Yip, Frank; Martin, Fernando; Rescigno, Thomas; McCurdy, C.
2013-05-01
Double photoionization of neon and argon differ significantly from helium in that three different final state couplings of the residual double ion (1 S , 1 D , and 3 P) are possible and greatly impact the observed angular distributions, but the multi-electron nature of such targets makes ab initio theoretical treatments of this correlated process a challenge. Triply differential cross sections (TDCS) have been calculated for single photon double ionization of these heavier rare gases at various photon energies by utilizing an expanded frozen-core treatment to represent the remaining N - 2 target electrons of the residual ion. The resulting angular distributions are compared with and show significant agreement with existing experimental data. Work supported by U. S. Dept. of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences Contract DE-AC02-05CH11231, by the MICINN Projects No. FIS2010-15127, No. ACI2008-0777,No. CSD 2007-00010, and ERC Advanced Grant 290853.
19. Lifetimes of metastable levels of singly ionized titanium: theory and experiment
International Nuclear Information System (INIS)
Palmeri, P; Quinet, P; Biemont, E; Gurell, J; Lundin, P; Royen, P; Mannervik, S; Norlin, L-O; Blagoev, K
2008-01-01
This paper presents new theoretical lifetimes of metastable levels in singly ionized titanium, Ti II. Along with the lifetimes, transition probabilities for several decay channels from these metastable levels are presented. The calculations are supported by experimental lifetime determinations of the 3d 3 b 2 D 5/2 and 3d 2 ( 3 P)4s b 2 P 3/2 levels along with revised values of the previously published lifetimes of the 3d 2 ( 3 P)4s b 4 P 5/2 and 3d 2 ( 3 P)4s b 2 P 1/2 levels originating partly from a reanalysis utilizing a recently developed method applied on the previously recorded data and partly from new measurements. The presented theoretical investigation of lifetimes of metastable levels in Ti II shows that the HFR calculations are in general compatible with measurements performed using the ion storage ring CRYRING of Stockholm University. The transition probabilities of forbidden lines derived from the new lifetime values will be useful for the diagnostics of low density laboratory or astrophysical plasmas, particularly those encountered in the strontium filament found in the ejecta of η Carinae
20. Exploring Redox Properties of Aromatic Amino Acids in Water: Contrasting Single Photon vs Resonant Multiphoton Ionization in Aqueous Solutions.
Science.gov (United States)
Roy, Anirban; Seidel, Robert; Kumar, Gaurav; Bradforth, Stephen E
2018-04-12
Direct measurements of the valence ionization energies and the reorganization energies of the three aromatic amino acids, l-tyrosine, l-tryptophan, and l-phenylalanine, in aqueous solution using the liquid microjet technique and two different photoemission methods-X-ray photoelectron spectroscopy (XPS) at 175 eV photon energy and resonant two-photon ionization (R2PI) using 2 × 267 nm (2 × 4.64 eV) UV laser light-are reported. l-Tryptophan has the lowest vertical ionization energy, 7.3 eV, followed by tyrosine (7.8 eV) and phenylalanine (∼8.7 eV). Essentially, no variation in recovered orbital energies is observed comparing near threshold ionization to X-ray ionization. Superior sensitivity of the (background-free) R2PI scheme for solutions with very low solute concentration (<2 mM) is demonstrated in contrast to the single-photon XPS measurements, which often requires solute concentrations of 0.1-1 molar. This higher sensitivity along with chemical selectivity of the R2PI technique can be exploited for both spectroscopic assignment and as an analytical tool. The nature of the adiabatic ionization energy for the three aromatic amino acids has been explored by the R2PI approach and by empirically formulating the correlation between the estimated ionization onset with electronic and nuclear relaxation on the excited state surface. Our results have implications for understanding one-electron transfer within enzymes and in redox situations where (ir)reversible deprotonation occurs such as those manifest in the biochemistry of oxidation damage.
1. Effects of ionizing radiation on cell-matrix interactions at the single molecule level
Energy Technology Data Exchange (ETDEWEB)
Lauer, Florian
2015-04-20
Single molecule microscopy is a technology that allows for accurate assessment of the location and motion of single fluorescent molecules, even in the context of observations on living biological samples. In the present thesis, a flexible analysis tool for single molecule data as obtained in biological experiments was established. The development of a tool to faithfully detect and localize diffraction-limited images of individual fluorescent probes was necessary since data acquired under cell cultivation conditions that account for a three-dimensional microenvironment as experienced physiologically by cells in native tissue poses a challenge not faced ordinarily. After design, implementation, quantitative tests using simulations for comparisons and verification, and evaluation of the different steps of the analysis procedure including local background estimation, local noise estimation, de-noising approaches, detection, localization, and post-processing, analysis capabilities were utilized to evaluate the impact of x-ray irradiation on the plasma membrane architecture of U2OS human osteosarcoma cells as assessed by tracking individual fluorescent lipid-mimetic dye molecules diffusing in the outer membrane leaflet. It was shown that lateral diffusion in the plasma membrane is well described as two-phase anomalous subdiffusion and presence of 3D extracellular matrix leads to lower anomalous exponents of the fast fraction in comparison to monolayer cell culture. Interestingly, even high single-dose (25 Gy) treatments known to induce membrane-mediated apoptosis in tumor microvessel endothelium via membrane viscosity enhancing ceramide generation were not observed to alter membrane architecture in U2OS cells which can be related to amplifying, feedback-driven redox-signaling in the endothelium absent in U2OS. In summary, the sensitive and accurate framework developed in this thesis to assess minute changes of plasma membrane located dynamic processes did not uncover a
2. Electrical properties of InP:Fe single crystals implanted by phosphorus ions
International Nuclear Information System (INIS)
Radautsan, S.I.; Tiginyanu, I.M.; Pyshnaya, N.B.
1988-01-01
Investigations of phosphorus ion implantation in InP:Fe monocrystals and of the post-implantation annealing process upon the electrical properties of InP:Fe were carried out. The electrical parameters of the samples have been determined by Hall effect measurements. The curves of electron surface concentration n s and mobility μ s as functions of annealing temperature in the range of 200 to 600 0 C are shown and discussed. In order to estimate the depth of donor levels in annealed samples the temperature dependence of the surface Hall coefficient has been studied in the range 100 to 400 K. The thermal electron activation energy has been determined to be 0.09 eV
3. Lifetime measurements and oscillator strengths in singly ionized scandium and the solar abundance of scandium
Science.gov (United States)
Pehlivan Rhodin, A.; Belmonte, M. T.; Engström, L.; Lundberg, H.; Nilsson, H.; Hartman, H.; Pickering, J. C.; Clear, C.; Quinet, P.; Fivet, V.; Palmeri, P.
2017-12-01
The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s and 4p2) in the region 57 743-77 837 cm-1 of singly ionized scandium (Sc II) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator strengths of 57 lines from these highly excited upper levels were derived using a hollow cathode discharge lamp and a Fourier transform spectrometer. In addition, Hartree-Fock calculations where both the main relativistic and core-polarization effects were taken into account were carried out for both low- and high-excitation levels. There is a good agreement for most of the lines between our calculated branching fractions and the measurements of Lawler & Dakin in the region 9000-45 000 cm-1 for low excitation levels and with our measurements for high excitation levels in the region 23 500-63 100 cm-1. This, in turn, allowed us to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical oscillator strengths for a set of 380 E1 transitions in Sc II. These oscillator strengths include the weak lines that were used previously to derive the solar abundance of scandium. The solar abundance of scandium is now estimated to logε⊙ = 3.04 ± 0.13 using these semi-empirical oscillator strengths to shift the values determined by Scott et al. The new estimated abundance value is in agreement with the meteoritic value (logεmet = 3.05 ± 0.02) of Lodders, Palme & Gail.
4. Low-mobility-pass filter between atmospheric pressure chemical ionization and electrospray ionization sources and a single quadrupole mass spectrometer: computational models and measurements.
Science.gov (United States)
Menlyadiev, Marlen R; Tadjimukhamedov, Fatkhulla Kh; Tarassov, Alexander; Wollnik, Hermann; Eiceman, Gary A
2014-01-15
Mixtures of ions produced in sources at atmospheric pressure, including chemical ionization (APCI) and electrospray ionization (ESI) can be simplified at or near ambient pressure using ion mobility based filters. A low-mobility-pass filter (LMPF) based on a simple mechanical design and simple electronic control was designed, modeled and tested with vapors of 2-hexadecanone in an APCI source and with spray of peptide solutions in an ESI source. The LMPF geometry was planar and small (4 mm wide × 13 mm long) and electric control was through a symmetric waveform in low kHz with amplitude between 0 and 10 V. Computational models established idealized performance for transmission efficiency of ions of several reduced mobility coefficients over the range of amplitudes and were matched by computed values from ion abundances in mass spectra. The filter exhibited a broad response function, equivalent to a Bode Plot in electronic filters, suggesting that ion filtering could be done in blocks ~50 m/z units wide. The benefit of this concept is that discrimination against ions of high mobility is controlled by only a single parameter: waveform amplitude at fixed frequency. The effective removal of high mobility ions, those of low mass-to-charge, can be beneficial for applications with ion-trap-based mass spectrometers to remove excessive levels of solvent or matrix ions. Copyright © 2013 John Wiley & Sons, Ltd.
5. Phosphorus poisoning in waterfowl
Science.gov (United States)
Coburn, D.R.; DeWitt, J.B.; Derby, J.V.; Ediger, E.
1950-01-01
Black ducks and mallards were found to be highly susceptible to phosphorus poisoning. 3 mg. of white phosphorus per kg. of body weight given in a single dose resulted in death of a black duck in 6 hours. Pathologic changes in both acute and chronic poisoning were studied. Data are presented showing that diagnosis can be made accurately by chemical analysis of stored tissues in cases of phosphorus poisoning.
6. Coherent nonlinear optical response of single-layer black phosphorus: third-harmonic generation
Science.gov (United States)
Margulis, Vladimir A.; Muryumin, Evgeny E.; Gaiduk, Evgeny A.
2017-10-01
We theoretically calculate the nonlinear optical (NLO) response of phosphorene (a black phosphorus monolayer) to a normally incident and linearly polarized coherent laser radiation of frequency ω, resulting in the generation of radiation at frequency 3ω. We derive explicit analytic expressions for four independent nonvanishing elements of the third-order NLO susceptibility tensor, describing the third-harmonic generation (THG) from phosphorene. The final formulas are numerically evaluated for typical values of the system's parameters to explore how the efficiency of the THG varies with both the frequency and the polarization direction of the incident radiation. The results obtained show a resonant enhancement of the THG efficiency when the pump photon energy ℏω approaches a value of one third of the bandgap energy Eg (≈1.5 eV) of phosphorene. It is also shown that the THG efficiency exhibits a specific polarization dependence, allowing the THG to be used for determining the orientation of phosphorene's crystallographic axes. Our findings highlight the material's potential for practical application in nanoscale photonic devices such as frequency convertors operating in the near-infrared spectral range.
7. Theoretical prediction of high carrier mobility in single-walled black phosphorus nanotubes
Science.gov (United States)
Li, Q. F.; Wang, H. F.; Yang, C. H.; Li, Q. Q.; Rao, W. F.
2018-05-01
One-dimensional semiconductors are promising materials for high-performance nanoscale devices. Using the first-principles calculations combined with deformation potential approximation, we study the electronic structures and carrier transport properties of black phosphorus nanotubes (BPNTs). It is found that both armchair and zigzag BPNTs with diameter 13.5-18.5 Å are direct bandgap semiconductors. At a similar diameter, the carrier mobility of zigzag BPNT is one order of magnitude larger than that of armchair BPNT. For armchair BPNTs, the electron mobility is about 90.70-155.33 cm2 V-1 s-1 at room temperature, which is about three times of its hole counterpart. For zigzag BPNTs, the maximum mobility can reach 2.87 ×103 cm2 V-1 s-1. Furthermore, the electronic properties can be effectively tuned by the strain. For zigzag (0,13) nanotube, there is a direct-to-indirect band gap transition at a tensile strain of about 6%. Moreover, the electron mobility is boosted sharply by one order of magnitude by applying the compressive or tensile strain. The electron mobility increases to 14.05 ×103 cm2 V-1 s-1 at a tensile strain of 9%. Our calculations highlight the tunable electronic properties and superior carrier mobility of BPNTs that are promising for interesting applications in future nano-electronic devices.
8. Numerical simulations of single and double ionization of H2 in short intense laser pulses
International Nuclear Information System (INIS)
Baier, Silvio
2008-01-01
Rescattering is the dominant process leading to double ionization in atoms and molecules interacting with linearly polarized laser pulses with wavelengths around 800 nm and in an intensity regime of 10 14 to 10 15 W/cm 2 . Using numerical integrations of the two-electron Schroedinger equation of the Hydrogen molecule in appropriate reduced dimensions two mechanisms, namely correlated emission of the electrons and excitation followed by field ionization after rescattering, could be identified and characterized. With the help of a planar model in reduced dimensions these mechanisms were quantitatively compared by their dependence on the molecular alignment with respect to the polarization axis. Two additional mechanisms, which are also related to rescattering, could be identified as well. (orig.)
9. Observation of terahertz-radiation-induced ionization in a single nano island.
Science.gov (United States)
Seo, Minah; Kang, Ji-Hun; Kim, Hyo-Suk; Hyong Cho, Joon; Choi, Jaebin; Min Jhon, Young; Lee, Seok; Hun Kim, Jae; Lee, Taikjin; Park, Q-Han; Kim, Chulki
2015-05-22
Terahertz (THz) electromagnetic wave has been widely used as a spectroscopic probe to detect the collective vibrational mode in vast molecular systems and investigate dielectric properties of various materials. Recent technological advances in generating intense THz radiation and the emergence of THz plasmonics operating with nanoscale structures have opened up new pathways toward THz applications. Here, we present a new opportunity in engineering the state of matter at the atomic scale using THz wave and a metallic nanostructure. We show that a medium strength THz radiation of 22 kV/cm can induce ionization of ambient carbon atoms through interaction with a metallic nanostructure. The prepared structure, made of a nano slot antenna and a nano island located at the center, acts as a nanogap capacitor and enhances the local electric field by two orders of magnitudes thereby causing the ionization of ambient carbon atoms. Ionization and accumulation of carbon atoms are also observed through the change of the resonant condition of the nano slot antenna and the shift of the characteristic mode in the spectrum of the transmitted THz waves.
10. Detection and mapping of Cannabinoids in single hair samples through rapid derivatization- Matrix-Assisted Laser Desorption Ionization Mass Spectrometry
OpenAIRE
Beasley, Emma; Francese, Simona; Bassindale, Thomas
2016-01-01
The sample preparation method reported in this work has permitted for the first time the application of Matrix Assisted Laser Desorption Ionization Mass Spectrometry Profiling and Imaging (MALDI-MSP and MALDI-MSI) for the detection and mapping of cannabinoids in a single hair sample. MALDI-MSI analysis of hair samples has recently been suggested as an alternative technique to traditional methods of GC-MS and LC-MS due to simpler sample preparation, the ability to detect a narrower time frame ...
11. First observation of two-electron one-photon transitions in single-photon K-shell double ionization.
Science.gov (United States)
Hoszowska, J; Dousse, J-Cl; Szlachetko, J; Kayser, Y; Cao, W; Jagodziński, P; Kavčič, M; Nowak, S H
2011-07-29
Experimental evidence for the correlated two-electron one-photon transitions (1s(-2)→2s(-1)2p(-1)) following single-photon K-shell double ionization is reported. The double K-shell vacancy states in solid Mg, Al, and Si were produced by means of monochromatized synchrotron radiation, and the two-electron one-photon radiative transitions were observed by using a wavelength dispersive spectrometer. The two-electron one-photon transition energies and the branching ratios of the radiative one-electron to two-electron transitions were determined and compared to available perturbation theory predictions and configuration interaction calculations.
12. Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation
International Nuclear Information System (INIS)
Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue
2014-01-01
Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)
13. The electron-impact ionization of Ar and Kr revisited: A critical analysis of double-to-single ionization cross section ratio measurements using the fast-atom-beam technique
International Nuclear Information System (INIS)
Tarnovsky, V.; Becker, K.
1992-01-01
We report new measurements of the absolute electron-impact double ionization cross sections for Ar and Kr and of the ratios of double-to-single ionization for impact energies from threshold to 200 eV using the crossed electron-beam - fast-atom-beam technique. The work was motivated by the recently highlighted spread of about 30% in the Ar 2+ /Ar + ionization cross section ratios obtained by several groups using different experimental techniques. Such a spread is inconsistent with statistical uncertainties of typically 3% or less that were quoted for the various reported ratios. A similar situation exists for Kr where the spread among the recently published Kr 2+ /Kr + ionization cross section ratios is about 15%. We made an attempt to identify all potential systematic errors inherent to the fast-beam technique that could affect the measurement of cross section ratios with special emphasis on those systematic errors that could influence the detection of singly and doubly charged product ions differently. We found Ar 2+ /Ar + and Kr 2+ /Kr + cross section ratios of, respectively 0.066±0.007 and 0.087±0.008 at 100 eV which confirm earlier measurements using the same experimental technique. The error limits on cross sections ratios of multiple-to-single ionization for the same target atom and at least ±10% for ratios of single ionization cross sections for different target species. Our error limits are dominated by systematic uncertainties of the apparatus which do not cancel when cross section ratios are measured, since the ratios are obtained under similar, but not identical experimental conditions. (orig.)
14. Indicators: Phosphorus
Science.gov (United States)
Phosphorus, like nitrogen, is a critical nutrient required for all life. Phosphate (PO4), which plays major roles in the formation of DNA, cellular energy, and cell membranes (and plant cell walls). Too much phosphorus can create water quality problems.
15. Single-carrier impact ionization favored by a limited band dispersion
OpenAIRE
Darbandi, A.; Rubel, O.
2012-01-01
A critical requirement for high gain and low noise avalanche photodiodes is the single-carrier avalanche multiplication. We propose that the single-carrier avalanche multiplication can be achieved in materials with a limited width of the conduction or valence band resulting in a restriction of kinetic energy for one of the charge carriers. This feature is not common to the majority of technologically relevant semiconductors, but it is observed in chalcogenides, such as Selenium and compound I...
16. Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions
Energy Technology Data Exchange (ETDEWEB)
Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)
2007-09-15
Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.
17. Microarray analysis of the transcriptional response to single or multiple doses of ionizing radiation in human subcutaneous fibroblasts
DEFF Research Database (Denmark)
Rødningen, Olaug Kristin; Overgaard, Jens; Alsner, Jan
2005-01-01
cell lines after various ionizing radiation (IR) schemes in order to provide information on potential targets for prevention and to suggest candidate genes for SNP association studies aimed at predicting individual risk of radiation-induced morbidity. PATIENTS AND METHODS: Thirty different human......BACKGROUND AND PURPOSE: Transcriptional profiling of fibroblasts derived from breast cancer patients might improve our understanding of subcutaneous radiation-induced fibrosis. The aim of this study was to get a comprehensive overview of the changes in gene expression in subcutaneous fibroblast...... fibroblast cell lines were included in the study, and two different radiation schemes; single dose experiments with 3.5 Gy or fractionated with 3 x 3.5 Gy. Expression analyses were performed on unexposed and exposed cells after different time points. The IR response was analyzed using the statistical method...
18. Response of microchannel plates in ionization mode to single particles and electromagnetic showers
Science.gov (United States)
Barnyakov, A. Yu.; Barnyakov, M. Yu.; Brianza, L.; Cavallari, F.; Cipriani, M.; Ciriolo, V.; del Re, D.; Gelli, S.; Ghezzi, A.; Gotti, C.; Govoni, P.; Katcin, A. A.; Malberti, M.; Martelli, A.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Pigazzini, S.; Preiato, F.; Prisekin, V. G.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Tabarelli de Fatis, T.
2018-01-01
Hundreds of concurrent collisions per bunch crossing are expected at future hadron colliders. Precision timing calorimetry has been advocated as a way to mitigate the pileup effects and, thanks to their excellent time resolution, microchannel plates (MCPs) are good candidate detectors for this goal. We report on the response of MCPs, used as secondary emission detectors, to single relativistic particles and to electromagnetic showers. Several prototypes, with different geometries and characteristics, were exposed to particle beams at the INFN-LNF Beam Test Facility and at CERN. Their time resolution and efficiency are measured for single particles and as a function of the multiplicity of particles. Efficiencies between 50% and 90% to single relativistic particles are reached, and up to 100% in presence of a large number of particles. Time resolutions between 20 ps and 30 ps are obtained.
19. Phosphorus, Agriculture & The Environment
OpenAIRE
Mullins, Gregory Lee
2009-01-01
Discusses potential environmental impacts of phosphorus, the functions of phosphorus in plants and animals, and the soil phosphorus cycle. Notes methods for controlling phosphorus losses to surface waters
20. Single and multiple ionization of C60 fullerenes and collective effects in collisions with highly charged C, F, and Si ions with energy 3 MeV/u
Science.gov (United States)
Kelkar, A. H.; Kadhane, U.; Misra, D.; Gulyas, L.; Tribedi, L. C.
2010-10-01
We have measured absolute cross sections for single, double, triple, and quadruple ionization of C60 in collisions with 3 MeV/u C, F, and Si projectile ions at various projectile charge states. The experiment was performed using the recoil-ion time-of-flight technique. Projectile charge state dependence of the ionization yields was compared mainly with a model based on the giant dipole plasmon resonance (GDPR). In some cases, the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) model which is normally applied for ion-atom collisions was also used as a reference. An excellent qualitative agreement between the experimental data for single and double ionization and the GDPR model predictions was found for all projectile charge states.
1. Single and multiple ionization of C60 fullerenes and collective effects in collisions with highly charged C, F, and Si ions with energy 3 MeV/u
International Nuclear Information System (INIS)
Kelkar, A. H.; Kadhane, U.; Misra, D.; Tribedi, L. C.; Gulyas, L.
2010-01-01
We have measured absolute cross sections for single, double, triple, and quadruple ionization of C 60 in collisions with 3 MeV/u C, F, and Si projectile ions at various projectile charge states. The experiment was performed using the recoil-ion time-of-flight technique. Projectile charge state dependence of the ionization yields was compared mainly with a model based on the giant dipole plasmon resonance (GDPR). In some cases, the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) model which is normally applied for ion-atom collisions was also used as a reference. An excellent qualitative agreement between the experimental data for single and double ionization and the GDPR model predictions was found for all projectile charge states.
2. Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors
Science.gov (United States)
Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura
2018-03-01
We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range <1 GeV /c2 . We argue that single-electron-resolution semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.
3. Dynamics of the single and double ionization of helium in fast proton collisions
International Nuclear Information System (INIS)
Doerner, R.; Schmidt-Boecking, H.
1991-08-01
A new experimental approach, designed to measure differential ionisation and electron capture cross sections for relativistic heavy ion beams, has been developed and was used to investigate dynamic mechanisms of Helium single and double ionisation in collisions with fast protons. Detailed insight into the dynamics of the ionisation process has been obtained. The experimental results prove, that the many-body momentum exchange between all particles involved, the projectile and target nucleus as well as the emitted electrons, has to be incorporated in order to correctly describe the ionisation collision dynamics. For the proton on Helium collision system the transverse momenta of projectile and recoil-ion were found to be of comparable magnitude only for very close collisions and large scattering angles above 1 mrad, which contribute less than 3% to the total ionisation cross section. (orig./HSI) [de
4. Total ionizing dose (TID) effect and single event effect (SEE) in quasi-SOI nMOSFETs
International Nuclear Information System (INIS)
Tan, Fei; Huang, Ru; An, Xia; Wu, Weikang; Feng, Hui; Huang, Liangxi; Fan, Jiewen; Zhang, Xing; Wang, Yangyuan
2014-01-01
This paper studies the total ionizing dose (TID) and single event effect (SEE) in quasi-SOI nMOSFETs for the first time. After exposure to gamma rays, the off-state leakage current (I off ) of a quasi-SOI device increases with the accumulating TID, and the on-state bias configuration is shown to be the worst-case bias configuration during irradiation. Although an additional TID-sensitive region is introduced by the unique structure of the quasi-SOI device, the influence of positive charge trapped in L-type oxide layers on the degradation of device performance is neglectable. Since the TID-induced leakage path in the quasi-SOI device is greatly reduced due to the isolation of L-type oxide layers, the TID-induced I off degradation in the quasi-SOI device is greatly suppressed. In addition, 3D simulation is performed to investigate the SEE of the quasi-SOI device. The full-width at half-maximum (FWHM) of worst-case drain current transient and collected charges of the quasi-SOI device after single-ion-striking is smaller than in a bulk Si device, indicating that the quasi-SOI device inherits the advantage of an SOI device in single event transient immunity. Therefore, the quasi-SOI device, which has improved electrical properties and radiation-hardened characteristics for both TID and SEE, can be considered as one of the promising candidates for space applications. (paper)
5. Biochar produced from biosolids using a single-mode microwave: Characterisation and its potential for phosphorus removal.
Science.gov (United States)
Antunes, Elsa; Schumann, James; Brodie, Graham; Jacob, Mohan V; Schneider, Philip A
2017-07-01
The amount of biosolids increases every year, and social and environmental concerns are also rising due to heavy metals and pathogen contamination. Even though biosolids are considered as a waste material, they could be used as a precursor in several applications, especially in agriculture due to the presence of essential nutrients. Microwave assisted pyrolysis (MWAP) is a promising technology to safely manage biosolids, while producing value-added products, such as biochar, that can be used to improve soil fertility. This study examined the impact of pyrolysis temperature between 300 °C and 800 °C on the chemical and physical properties of biochar obtained from biosolids via MWAP. Preliminary phosphorus adsorption tests were carried out with the biochar produced from biosolids. This research demonstrated that pyrolysis temperature affects biochar specific surface area, ash and volatiles content, but does not impact heavily on the pH, chemical composition and crystalline phases of the resultant biochar. Biochar yield decreases as the pyrolysis temperature increases. Phosphorus adsorption capacity of biochar was approximately around 15 mg/g of biochar. Biochar resulting from MWAP is a potential candidate for land application with an important role in water and nutrient retention, due to the high surface area. Copyright © 2017 Elsevier Ltd. All rights reserved.
6. Charge enhancement of single-stranded DNA in negative electrospray ionization using the supercharging reagent meta-nitrobenzyl alcohol.
Science.gov (United States)
Brahim, Bessem; Alves, Sandra; Cole, Richard B; Tabet, Jean-Claude
2013-12-01
Charge enhancement of single-stranded oligonucleotide ions in negative ESI mode is investigated. The employed reagent, meta-nitrobenzyl alcohol (m-NBA), was found to improve total signal intensity (Itot), increase the highest observed charge states (zhigh), and raise the average charge states (zavg) of all tested oligonucleotides analyzed in negative ESI. To quantify these increases, signal enhancement ratios (SER1%) and charge enhancement coefficients (CEC1%) were introduced. The SER1%, (defined as the quotient of total oligonucleotide ion abundances with 1% m-NBA divided by total oligonucleotide abundance without m-NBA) was found to be greater than unity for every oligonucleotide tested. The CEC1% values (defined as the average charge state in the presence of 1% m-NBA minus the average charge state in the absence of m-NBA) were found to be uniformly positive. Upon close inspection, the degree of charge enhancement for longer oligonucleotides was found to be dependent upon thymine density (i.e., the number and the location of phospho-thymidine units). A correlation between the charge enhancement induced by the presence of m-NBA and the apparent gas-phase acidity (largely determined by the sequence of thymine units but also by the presence of protons on other nucleobases) of multiply deprotonated oligonucleotide species, was thus established. Ammonium cations appeared to be directly involved in the m-NBA supercharging mechanism, and their role seems to be consistent with previously postulated ESI mechanisms describing desorption/ionization of single-stranded DNA into the gas phase.
7. Charge Enhancement of Single-Stranded DNA in Negative Electrospray Ionization Using the Supercharging Reagent Meta-nitrobenzyl Alcohol
Science.gov (United States)
Brahim, Bessem; Alves, Sandra; Cole, Richard B.; Tabet, Jean-Claude
2013-12-01
Charge enhancement of single-stranded oligonucleotide ions in negative ESI mode is investigated. The employed reagent, meta-nitrobenzyl alcohol (m-NBA), was found to improve total signal intensity (Itot), increase the highest observed charge states (zhigh), and raise the average charge states (zavg) of all tested oligonucleotides analyzed in negative ESI. To quantify these increases, signal enhancement ratios (SER1%) and charge enhancement coefficients (CEC1%) were introduced. The SER1%, (defined as the quotient of total oligonucleotide ion abundances with 1 % m-NBA divided by total oligonucleotide abundance without m-NBA) was found to be greater than unity for every oligonucleotide tested. The CEC1% values (defined as the average charge state in the presence of 1 % m-NBA minus the average charge state in the absence of m-NBA) were found to be uniformly positive. Upon close inspection, the degree of charge enhancement for longer oligonucleotides was found to be dependent upon thymine density (i.e., the number and the location of phospho-thymidine units). A correlation between the charge enhancement induced by the presence of m-NBA and the apparent gas-phase acidity (largely determined by the sequence of thymine units but also by the presence of protons on other nucleobases) of multiply deprotonated oligonucleotide species, was thus established. Ammonium cations appeared to be directly involved in the m-NBA supercharging mechanism, and their role seems to be consistent with previously postulated ESI mechanisms describing desorption/ionization of single-stranded DNA into the gas phase.
8. Dissociation kinetics of excited ions: PEPICO measurements of Os3(CO)12 — The 7-35 eV single ionization binding energy region
Science.gov (United States)
Schalk, Oliver; Josefsson, Ida; Geng, Ting; Richter, Robert; Sa'adeh, Hanan; Thomas, Richard D.; Mucke, Melanie
2018-02-01
In this article, we study the photoinduced dissociation pathways of a metallocarbonyl, Os3(CO)12, in particular the consecutive loss of CO groups. To do so, we performed photoelectron-photoion coincidence (PEPICO) measurements in the single ionization binding energy region from 7 to 35 eV using 45-eV photons. Zero-energy ion appearance energies for the dissociation steps were extracted by modeling the PEPICO data using the statistical adiabatic channel model. Upon ionization to the excited ionic states above 13 eV binding energy, non-statistical behavior was observed and assigned to prompt CO loss. Double ionization was found to be dominated by the knockout process with an onset of 20.9 ± 0.4 eV. The oscillator strength is significantly larger for energies above 26.6 ± 0.4 eV, corresponding to one electron being ejected from the Os3 center and one from the CO ligands. The cross section for double ionization was found to increase linearly up to 35 eV ionization energy, at which 40% of the generated ions are doubly charged.
9. Single gas chromatography method with nitrogen phosphorus detector for urinary cotinine determination in passive and active smokers
Directory of Open Access Journals (Sweden)
Lusiane Malafatti
2010-12-01
Full Text Available Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD. Urine (5.0 mL was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 μL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986 and 0.9952, respectively. Intra- and inter-assay standard relative deviations were lower than 14.2 %, while inaccuracy (bias was less than +11.9%. The efficiency of extraction was greater than 88.5%. Ruggedness was verified, according to Youden's test. Means of cotinine concentrations observed were 2,980 ng mL-1 for active smokers and 132 ng mL-1, for passive smokers. The results revealed that satisfactory chromatographic separation between the analyte and interferents was obtained with a ZB-1 column. This method is reliable, precise, linear and presented ruggedness in the range evaluated. The results suggest that it can be applied in routine analysis for passive and active smokers, since it is able to quantify a wide range of cotinine concentrations in urine.A nicotina é uma substância presente no cigarro capaz de causar dependência, sendo biotransformada em vários metabólitos nos seres humanos, dentre eles a cotinina urinária, que é considerada um indicador biológico de exposição à nicotina, devido a suas altas concentrações, comparado a outras matrizes. Assim, o objetivo deste estudo foi desenvolver um único método para determinação de cotinina urinária, em amostras de
10. Phosphorus Test
Science.gov (United States)
... and Iron-binding Capacity (TIBC, UIBC) Trichomonas Testing Triglycerides Troponin Tryptase Tumor Markers Uric Acid Urinalysis Urine ... lpi.orst.edu/infocenter/minerals/phosphorus/ . Merck. Phosphate Metabolism. The Merck Manual of Diagnosis and Therapy [On- ...
11. 2 mm range ESR of the transmutation-produced phosphorus impurity in 6HSiC
International Nuclear Information System (INIS)
Kalabukhova, E.N.; Lukin, S.N.; Mokhov, E.N.
1993-01-01
Phosphorus impurity is introduced into 6HSiC monocrystals via neutron transmutation doping. Parameters of ESR two spectra referred to ESR spectra of separated phosphorus atoms in the lattice cubic and hexagonal position are detected and determined in the specimens at T=4.2 K. variation dynamics of ESR spectra of phosphorus and nitrogen within 4.2-73 K temperature range is studied. Ionization energies of phosphorus atoms are determined to be less, than those of nitrogen atoms, and ionization energy of phosphorus atoms in hexagonal position is higher, than that of phosphorus atoms in cubic position
12. Measured, calculated and predicted Stark widths of the singly ionized C, N, O, F, Ne, Si, P, S, Cl and Ar spectral lines
Directory of Open Access Journals (Sweden)
Djeniže S.
2000-01-01
Full Text Available In order to find reliable Stark width data, needed in plasma spectroscopy comparision between the existing measured, calculated and predicted Stark width values was performed for ten singly ionized emitters: C, N, O, F, Ne Si, P, S, Cl and Ar in the lower lying 3s - 3p, 3p - 3d and 4s - 4p transitions. These emitters are present in many cosmic light sources. On the basis of the agreement between mentioned values 17 spectral lines from six singly ionized spectra have been recommended, for the first time, for plasma spectroscopy as spectral lines with reliable Stark width data. Critical analysis of the existing Stark width data is also given.
13. Single Photon Ionization Mass Spectroscopy of Hydrogen Bonded and van der Waals Cluster Systems Using a Capillary Discharge Soft X-Ray Laser
Science.gov (United States)
Heinbuch, S.; Dong, F.; Bernstein, E. R.; Rocca, J. J.
We report the first use of a soft x-ray laser in photochemistry studies. A 46.9 nm capillary discharge soft x-ray laser was used to study hydrogen bonded and van der Waals cluster systems. The study of van der Waals cluster formation and growth in the gas phase can contribute to the understanding of solvation processes, solvation dynamics, and the nucleation and growth of small clusters. The comparative investigation of water, methanol, and ammonia clusters is of importance because these clusters demonstrate a wide range of van der Waals interactions and hydrogen bonding: water clusters are very strongly and dominantly hydrogen bonded; methanol clusters somewhat less so; and ammonia clusters perhaps not at all. Sulfur dioxide is the major contributor to acid rain and a generator of soot. The process of SO2 and water forming acid rain has been studied for some time in order to determine the atmospheric mechanism for this environmental issue. Carbon dioxide is the major gas phase pollutant responsible for the "green house effect" of the atmosphere. Many experiments employing supersonic expansion coupled with mass spectroscopic detection have been conducted in order to study monomeric and clustered structure and behavior of each of these systems. Spectroscopic and photochemical properties of the systems should be related to cluster structure. However, one of the most serious problems in the investigation of the distribution of neutral hydrogen-bonded and van der Waals clusters is the fragmentation or the intra-cluster ion-molecule reactions to the protonated cluster ions. Electron Impact (EI) ionization usually suffers considerably from fragmentation of parent cluster ions on account of the large excess energies during the ionization process. Multiphoton ionization (MPI) processes result in the predissociation of the neutral clusters before ionization. Single photon ionization is a more "gentle" way to study hydrogen-bonded and Van der Waals clusters since less
14. Second-order Born effects in the coplanar to perpendicular plane single ionization of Xe (5p)
International Nuclear Information System (INIS)
Singh, Prithvi; Purohit, G; Patidar, Vinod
2013-01-01
Differential cross section results for the coplanar to perpendicular plane ionization of xenon atoms at incident electron energies of 40 and 20 eV above ionization potential are reported. The cross sections have been calculated in the modified distorted wave Born approximation (DWBA) formalism including the second-order Born amplitude. Our present attempt verifies the role of second-order processes in the ionization of xenon atoms at low and intermediate energy ranges. We compare the (e, 2e) triple differential cross section results of our calculation with the very recent measurements of Nixon and Murray (2012 Phys. Rev. A 85 022716) and relativistic DWBA-G results of Illarionov and Stauffer (2012 J. Phys. B: At. Mol. Opt. Phys. 45 225202). Overall agreement with measurements has been improved by inclusion of a second-order term in the description of the collision process. (paper)
15. Dual ionization chamber
International Nuclear Information System (INIS)
Mallory, J.; Turlej, Z.
1981-01-01
Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source
16. Slater-Koster Tight-Binding parametrization of single and few-layer Black-Phosphorus from first-principles calculations
Science.gov (United States)
Menezes, Marcos; Capaz, Rodrigo
Black Phosphorus (BP) is a promising material for applications in electronics, especially due to the tuning of its band gap by increasing the number of layers. In single-layer BP, also called Phosphorene, the P atoms form two staggered chains bonded by sp3 hybridization, while neighboring layers are bonded by Van-der-Waals interactions. In this work, we present a Tight-Binding (TB) parametrization of the electronic structure of single and few-layer BP, based on the Slater-Koster model within the two-center approximation. Our model includes all 3s and 3p orbitals, which makes this problem more complex than that of graphene, where only 2pz orbitals are needed for most purposes. The TB parameters are obtained from a least-squares fit of DFT calculations carried on the SIESTA code. We compare the results for different basis-sets used to expand the ab-initio wavefunctions and discuss their applicability. Our model can fit a larger number of bands than previously reported calculations based on Wannier functions. Moreover, our parameters have a clear physical interpretation based on chemical bonding. As such, we expect our results to be useful in a further understanding of multilayer BP and other 2D-materials characterized by strong sp3 hybridization. CNPq, FAPERJ, INCT-Nanomateriais de Carbono.
17. Single-objective vs. multi-objective autocalibration in modelling total suspended solids and phosphorus in a small agricultural watershed with SWAT.
Science.gov (United States)
Rasolomanana, Santatriniaina Denise; Lessard, Paul; Vanrolleghem, Peter A
2012-01-01
To obtain greater precision in modelling small agricultural watersheds, a shorter simulation time step is beneficial. A daily time step better represents the dynamics of pollutants in the river and provides more realistic simulation results. However, with a daily evaluation performance, good fits are rarely obtained. With the Shuffled Complex Evolution (SCE) method embedded in the Soil and Water Assessment Tool (SWAT), two calibration approaches are available, single-objective or multi-objective optimization. The goal of the present study is to evaluate which approach can improve the daily performance with SWAT, in modelling flow (Q), total suspended solids (TSS) and total phosphorus (TP). The influence of weights assigned to the different variables included in the objective function has also been tested. The results showed that: (i) the model performance depends not only on the choice of calibration approach, but essentially on the influential parameters; (ii) the multi-objective calibration estimating at once all parameters related to all measured variables is the best approach to model Q, TSS and TP; (iii) changing weights does not improve model performance; and (iv) with a single-objective optimization, an excellent water quality modelling performance may hide a loss of performance of predicting flows and unbalanced internal model components.
18. Gas gain operations with single photon resolution using an integrating ionization chamber in small-angle X-ray scattering experiments
CERN Document Server
Menk, R H; Besch, H J; Walenta, Albert H; Amenitsch, H; Bernstorff, S
2000-01-01
In this work a combination of an ionization chamber with one-dimensional spatial resolution and a MicroCAT structure will be presented. Initially, MicroCAT was thought of as a shielding grid (Frisch-grid) but later was used as an active electron amplification device that enables single X-ray photon resolution measurements at low fluxes even with integrating readout electronics. Moreover, the adjustable gas gain that continuously covers the entire range from pure ionization chamber mode up to high gas gains (30000 and more) provides stable operation yielding a huge dynamic range of about 10 sup 8 and more. First measurements on biological samples using small angle X-ray scattering techniques with synchrotron radiation will be presented.
19. Association analysis for detecting significant single nucleotide polymorphisms for phosphorus-deficiency tolerance at the seedling stage in soybean [Glycine max (L) Merr].
Science.gov (United States)
Ning, Lihua; Kan, Guizhen; Du, Wenkai; Guo, Shiwei; Wang, Qing; Zhang, Guozheng; Cheng, Hao; Yu, Deyue
2016-03-01
Tolerance to low-phosphorus soil is a desirable trait in soybean cultivars. Previous quantitative trait locus (QTL) studies for phosphorus-deficiency tolerance were mainly derived from bi-parental segregating populations and few reports from natural population. The objective of this study was to detect QTLs that regulate phosphorus-deficiency tolerance in soybean using association mapping approach. Phosphorus-deficiency tolerance was evaluated according to five traits (plant shoot height, shoot dry weight, phosphorus concentration, phosphorus acquisition efficiency and use efficiency) comprising a conditional phenotype at the seedling stage. Association mapping of the conditional phenotype detected 19 SNPs including 13 SNPs that were significantly associated with the five traits across two years. A novel cluster of SNPs, including three SNPs that consistently showed significant effects over two years, that associated with more than one trait was detected on chromosome 3. All favorable alleles, which were determined based on the mean of conditional phenotypic values of each trait over the two years, could be pyramided into one cultivar through parental cross combination. The best three cross combinations were predicted with the aim of simultaneously improving phosphorus acquisition efficiency and use efficiency. These results will provide a thorough understanding of the genetic basis of phosphorus deficiency tolerance in soybean.
20. Total Ionizing Dose Influence on the Single Event Effect Sensitivity in Samsung 8Gb NAND Flash Memories
Science.gov (United States)
Edmonds, Larry D.; Irom, Farokh; Allen, Gregory R.
2017-08-01
A recent model provides risk estimates for the deprogramming of initially programmed floating gates via prompt charge loss produced by an ionizing radiation environment. The environment can be a mixture of electrons, protons, and heavy ions. The model requires several input parameters. This paper extends the model to include TID effects in the control circuitry by including one additional parameter. Parameters intended to produce conservative risk estimates for the Samsung 8 Gb SLC NAND flash memory are given, subject to some qualifications.
1. Single window for issuing licenses for export and import of ionizing radiation sources and transit of radioactive sources
International Nuclear Information System (INIS)
Sandev, T.; Stamenov, R.; Misevska, A.; Georgievska-Dimitrevski, B.; Angelovski, G.
2009-01-01
In this paper we present the electronic system for application and issuing licenses for export, import and transit of goods (EXIM), particularly for ionizing radiation sources, in the Republic of Macedonia. This system is a modern and helpful tool for simple issuing licenses, for establishing a unique database and it represents a harmonized system for exchanging information between the governmental, public and private legal persons in the Republic of Macedonia. (author)
2. Single photon simultaneous K-shell ionization and K-shell excitation. II. Specificities of hollow nitrogen molecular ions
International Nuclear Information System (INIS)
Carniato, S.; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P.; Žitnik, M.; Bučar, K.; Nakano, M.; Hikosaka, Y.; Ito, K.
2015-01-01
The formalism developed in the companion Paper I is used here for the interpretation of spectra obtained recently on the nitrogen molecule. Double core-hole ionization K −2 and core ionization-core excitation K −2 V processes have been observed by coincidence electron spectroscopy after ionization by synchrotron radiation at different photon energies. Theoretical and experimental cross sections reported on an absolute scale are in satisfactory agreement. The evolution with photon energy of the relative contribution of shake-up and conjugate shake-up processes is discussed. The first main resonance in the K −2 V spectrum is assigned to a K −2 π ∗ state mainly populated by the 1s→ lowest unoccupied molecular orbital dipolar excitation, as it is in the K −1 V NEXAFS (Near-Edge X-ray Absorption Fine Structure) signals. Closer to the K −2 threshold Rydberg resonances have been also identified, and among them a K −2 σ ∗ resonance characterized by a large amount of 2s/2p hybridization, and double K −2 (2σ ∗ /1π/3σ) −1 1π ∗2 shake-up states. These resonances correspond in NEXAFS spectra to, respectively, the well-known σ ∗ shape resonance and double excitation K −1 (2σ ∗ /1π/3σ) −1 1π ∗2 resonances, all being positioned above the threshold
3. Absolute experimental cross sections for the electron impact single, double, triple, and quadruple ionization of Cs/sup +/ ions. Final technical report
Energy Technology Data Exchange (ETDEWEB)
Feeney, R.K.; Hertling, D.R.
1981-02-28
The absolute cross sections for the single, double, triple and quadruple ionization of Cs/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. This determination has been accomplshed using a crossed beam facility in which monoenergetic beams of ions and electrons are caused to intersect at right angles in a well-defined collision volume. Multiply charged, product ions born as a result of the electron impact are deflected into their respective detectors by cascaded electrostatic analyzers. The multiply charged beam current component is measured by means of a vibrating reed electrometer operating in the rate-of-charge mode.
4. Combination of granular activated carbon adsorption and deep-bed filtration as a single advanced wastewater treatment step for organic micropollutant and phosphorus removal.
Science.gov (United States)
Altmann, Johannes; Rehfeld, Daniel; Träder, Kai; Sperlich, Alexander; Jekel, Martin
2016-04-01
5. Single photon simultaneous K-shell ionization and K-shell excitation. II. Specificities of hollow nitrogen molecular ions
Energy Technology Data Exchange (ETDEWEB)
Carniato, S., E-mail: [email protected]; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P. [Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614, Sorbonne Universités, UPMC University of Paris 6, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); LCPMR(UMR 7614), CNRS, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Žitnik, M.; Bučar, K. [Jozef Stefan Institute, P.O. Box 3000, SI-1001 Ljubljana (Slovenia); Nakano, M. [Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Photon Factory, Institute of Materials Structure Science, Tsukuba, Ibaraki 305-0801 (Japan); Hikosaka, Y. [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Ito, K. [Photon Factory, Institute of Materials Structure Science, Tsukuba, Ibaraki 305-0801 (Japan)
2015-01-07
The formalism developed in the companion Paper I is used here for the interpretation of spectra obtained recently on the nitrogen molecule. Double core-hole ionization K{sup −2} and core ionization-core excitation K{sup −2}V processes have been observed by coincidence electron spectroscopy after ionization by synchrotron radiation at different photon energies. Theoretical and experimental cross sections reported on an absolute scale are in satisfactory agreement. The evolution with photon energy of the relative contribution of shake-up and conjugate shake-up processes is discussed. The first main resonance in the K{sup −2}V spectrum is assigned to a K{sup −2}π{sup ∗} state mainly populated by the 1s→ lowest unoccupied molecular orbital dipolar excitation, as it is in the K{sup −1}V NEXAFS (Near-Edge X-ray Absorption Fine Structure) signals. Closer to the K{sup −2} threshold Rydberg resonances have been also identified, and among them a K{sup −2}σ{sup ∗} resonance characterized by a large amount of 2s/2p hybridization, and double K{sup −2}(2σ{sup ∗}/1π/3σ){sup −1}1π{sup ∗2} shake-up states. These resonances correspond in NEXAFS spectra to, respectively, the well-known σ{sup ∗} shape resonance and double excitation K{sup −1}(2σ{sup ∗}/1π/3σ){sup −1}1π{sup ∗2} resonances, all being positioned above the threshold.
6. Reduction of the phosphorus contamination for plasma deposition of p—i—n microcrystalline silicon solar cells in a single chamber
International Nuclear Information System (INIS)
Guang-Hong, Wang; Xiao-Dan, Zhang; Sheng-Zhi, Xu; Xin-Xia, Zheng; Chang-Chun, Wei; Jian, Sun; Shao-Zhen, Xiong; Xin-Hua, Geng; Ying, Zhao
2010-01-01
This paper investigates several pretreatment techniques used to reduce the phosphorus contamination between solar cells. They include hydrogen plasma pretreatment, deposition of a p-type doped layer, i-a-Si:H or μc-Si:H covering layer between solar cells. Their effectiveness for the pretreatment is evaluated by means of phosphorus concentration in films, the dark conductivity of p-layer properties and cell performance. (cross-disciplinary physics and related areas of science and technology)
7. Feasibility study of the single particle analysis of uranium by laser ionization time-of-flight mass spectrometry
International Nuclear Information System (INIS)
Ha, Yeong Keong; Han, Sun Ho; Pyo, Hyung Yeol; Park, Yong Joon; Song, Kyu Seok
2004-01-01
The control of activities in nuclear facilities worldwide is one of the most important tasks of nuclear safeguard. To meet the needs for nuclear safeguard, International Atomic Energy Agency (IAEA) strengthened the control of nuclear activities to detect these activities earlier. Thus, it is very important to develop analytical techniques to determine the isotopic composition of hot particles from swipe samples. The precise measurement of the 234 U/ 238 U, 235 U/ 238 U and 236 U/ 238 U ratios is important because it provides information about the initial enrichment of reactor uranium, core history, and post accident story. Because conventional α-spectrometry is not sufficiently sensitive for the determination of long-lived radionuclides in environmental samples, several analytical techniques, such as SNMS (Sputtered Neutral Mass Spectrometry), RIMS (Resonance Ionization Mass Spectrometry), AMS (Accelerator Mass Spectrometry) etc., have been proposed for uranium isotope measurements. In case of microparticles, analytical techniques such as SIMS (Secondary Ion Mass Spectrometry) have been applied for the isotopic characterization. The aim of this work was the development of a sensitive analytical technique for determination of isotopic ratio of uranium in swipe samples. In this work, feasibility of LIMS (Laser Ionization Mass Spectrometry) for the determination of such particles has been evaluated using a reference material of natural uranium
8. Study of combinations of TL/OSL single dosimeters for mixed high/low ionization density radiation fields
International Nuclear Information System (INIS)
Oster, L.; Druzhyna, S.; Orion, I.; Horowitz, Y.S.
2013-01-01
In this paper we discuss and compare the potential application of combined OSL/TL measurements using 6 LiF:Mg,Ti (TLD-600 is enriched of isotope 6 Li which has a high cross-section for the reaction with slow neutrons) or 7 LiF:Mg,Ti ( TLD-700 is enriched of 7 Li isotope) and TLD-100 (natural isotopic composition) detectors. The OSL/TL duel readout of LiF:Mg,Ti as an ionization density discriminator avoids some of the difficulties inherent to the various types of discrimination mixed-field passive dosimeters, and in addition has several advantages. The preferential excitation of OSL compared to TL following high ionization density (HID) alpha irradiation, naturally explained via the identification of OSL with the “two-hit” F 2 or F 3 center, whereas the major component of composite TL glow peak 5 is believed to arise from a ''one-hit'' complex defect. This evidence allows near-total discrimination between HID radiation and low-ionization density (LID) radiation. Beta and alpha particle irradiations were carried out with 90 Sr/ 90 Y (∼500 keV average energy) and 241 Am sources (4.7 MeV) respectively and neutron irradiations were carried out at the PTB (Germany) (E n = 5 MeV) and RARAF (Columbia University, USA) (E n = 6 MeV) accelerator facilities. The highest values of the FOM obtained was ∼30 for neutron/gamma discrimination and ∼110 for alpha/gamma discrimination using OSL/TL – peak 5 measurements in TLD-700. -- Highlights: ► The increased response of OSL compared to TL following HID irradiation is observed. ► This evidence is explained via the identification of OSL with the ''two-hit'' F2 centers. ► The potential application of combined OSL/TL in discrimination dosimetry is discussed. ► The values of FOM were 110 for alpha/gamma and 30 for neutron/gamma discrimination
9. Single photon ionization of van der Waals clusters with a soft x-ray laser: (CO2)n and (CO2)n(H2O)m.
Science.gov (United States)
Heinbuch, S; Dong, F; Rocca, J J; Bernstein, E R
2006-10-21
Pure neutral (CO2)n clusters and mixed (CO2)n(H2O)m clusters are investigated employing time of flight mass spectroscopy and single photon ionization at 26.5 eV. The distribution of pure (CO2)n clusters decreases roughly exponentially with increasing cluster size. During the ionization process, neutral clusters suffer little fragmentation because almost all excess cluster energy above the vertical ionization energy is taken away by the photoelectron and only a small part of the photon energy is deposited into the (CO2)n cluster. Metastable dissociation rate constants of (CO2)n+ are measured in the range of (0.2-1.5) x 10(4) s(-1) for cluster sizes of 5CO2-H2O clusters are studied under different generation conditions (5% and 20% CO2 partial pressures and high and low expansion pressures). At high CO2 concentration, predominant signals in the mass spectrum are the (CO2)n+ cluster ions. The unprotonated cluster ion series (CO2)nH2O+ and (CO2)n(H2O)2+ are also observed under these conditions. At low CO2 concentration, protonated cluster ions (H2O)nH+ are the dominant signals, and the protonated CO2(H2O)nH+ and unprotonated (H2O)n+ and (CO2)(H2O)n+ cluster ion series are also observed. The mechanisms and dynamics of the formation of these neutral and ionic clusters are discussed.
10. Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix.
Science.gov (United States)
Wang, Hang; Wang, Ying; Wang, Ge; Hong, Lizhi
2017-07-15
Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC-MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC-MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution. Copyright © 2017 Elsevier B.V. All rights reserved.
11. Ionization particle detector
International Nuclear Information System (INIS)
Ried, L.
1982-01-01
A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source
12. Compendium of Single-Event Latchup and Total Ionizing Dose Test Results of Commercial Analog to Digital Converters
Science.gov (United States)
Irom, Farokh; Agarwal, Shri G.
2012-01-01
This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.
13. Cell and Tissue Damage after Skin Exposure to Ionizing Radiation: Short- and Long-Term Effects after a Single and Fractional Doses.
Science.gov (United States)
Kinoshita, Kahori; Ishimine, Hisako; Shiraishi, Kenshiro; Kato, Harunosuke; Doi, Kentaro; Kuno, Shinichiro; Kanayama, Koji; Mineda, Kazuhide; Mashiko, Takanobu; Feng, Jingwei; Nakagawa, Keiichi; Kurisaki, Akira; Itami, Satoshi; Yoshimura, Kotaro
2014-01-01
Ionizing radiation is often used to treat progressive neoplasms. However, the consequences of long-term radiation exposure to healthy skin tissue are poorly understood. We aimed to evaluate the short- and long-term radiation damage to healthy skin of the same irradiation given either as single or fractional doses. C57BL/J6 mice were randomly assigned to one of three groups: a control and two exposure groups (5 Gy ×2 or 10 Gy ×1). The inguinal area was irradiated (6-MeV beam) 1 week after depilation in the treatment groups. Skin samples were evaluated macroscopically and histologically for up to 6 months after the final exposure. After anagen hair follicle injury by irradiation, hair cycling resumed in both groups, but hair graying was observed in the 10 Gy ×1 group but not in the 5 Gy ×2 group, suggesting the dose of each fractional exposure is more relevant to melanocyte stem cell damage than the total dose. On the other hand, in the long term, the fractional double exposures induced more severe atrophy and capillary reduction in the dermis and subcutis, suggesting fractional exposure may cause more depletion of tissue stem cells and endothelial cells in the tissue. Thus, our results indicated that there were differences between the degrees of damage that occurred as a result of a single exposure compared with fractional exposures to ionizing radiation: the former induces more severe acute injury to the skin with irreversible depigmentation of hairs, while the latter induces long-term damage to the dermis and subcutis. © 2015 S. Karger AG, Basel.
International Nuclear Information System (INIS)
Kruger, J.
1989-01-01
Ionizing radiation results in biological damage that differs from other hazardous substances and is highly dangerous to man. Ionizing radiation cannot be perceived by man's sense organs and the biological damage cannot be detected immediately afterwards (except in very high doses). Every human being is exposed to low doses of radiation. The structure of the atom; sources of ionizing radiation; radiation units; biological effects; norms for radiation protection; and the national control in South Africa are discussed. 1 fig., 5 refs
15. Ionization radiation curable polyacrylate resin coatings
International Nuclear Information System (INIS)
Miller, L.S.
1975-01-01
A carboxylic acid chloride or bromide, a sulfonyl chloride or bromide, cyanuric chloride, calcium hypochlorite or phosphorus oxychloride and optionally a buffering pigment are combined with a liquid, acrylate ester resin curable by exposure to high-energy ionizing radiation to yield a coating composition which upon being cured in air by exposure to ionizing radition yields a coating having an essentially tack-free surface. (Patent Office Record)
16. Dietary phosphorus, serum phosphorus, and cardiovascular disease.
Science.gov (United States)
Menon, Madhav C; Ix, Joachim H
2013-10-01
Recent epidemiologic studies have linked higher serum phosphorus concentrations to cardiovascular disease (CVD) events and mortality. This association has been identified in the general population and in those with chronic kidney disease (CKD). The risk of adverse outcomes appears to begin with phosphorus concentrations within the upper limit of the normal reference range. Multiple experimental studies have suggested pathogenetic mechanisms that involve direct and indirect effects of high phosphorus concentrations to explain these associations. Drawing from these observations, guideline-forming agencies have recommended that serum phosphorus concentrations be maintained within the normal reference range in patients with CKD and that dietary phosphorus restriction or use of intestinal phosphate binders should be considered to achieve this goal. However, outside the dialysis population, the links between dietary phosphorus intake and serum phosphorus concentrations, and dietary phosphorus intake and CVD events, are uncertain. With specific reference to the nondialysis populations, this review discusses the available data linking dietary phosphorus intake with serum phosphorus concentrations and CVD events. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
17. Highly resolved online organic-chemical speciation of evolved gases from thermal analysis devices by cryogenically modulated fast gas chromatography coupled to single photon ionization mass spectrometry.
Science.gov (United States)
Saraji-Bozorgzad, Mohammad R; Eschner, Markus; Groeger, Thomas M; Streibel, Thorsten; Geissler, Robert; Kaisersberger, Erwin; Denner, Thomas; Zimmermann, Ralf
2010-12-01
Multi-dimensional analysis (MDA) in analytical chemistry is often applied to improve the selectivity of an analytical device and, therefore, to achieve a better overview of a sample composition. Recently, the hyphenation of thermogravimetry with single photo ionization mass spectrometry (TG-SPIMS) using an electron beam pumped excimer lamp (EBEL) for VUV radiation was applied. The concept of MDA has been realized by upgrading the TG-SPIMS system with a quasi comprehensive chromatographic separation step before the soft ionization (TG-GCxSPIMS). The system was characterized by the thermal analysis of diesel fuel, which has often been investigated by the GCxGC-community and is therefore a well-known sample material in MDA. Data from this measurement are used to explain the three-dimensional data structure and the advantages of the online TG-GCxSPIMS as compared to TG-SPIMS. Subsequently, the thermal decomposition behavior of a polymer, acrylonitrile-butadiene-styrene (ABS), is investigated. TG-GCxSPIMS provides a two-dimensional analysis of the evolved gaseous products. TG relevant data are obtained as well as an improved resolution power to separate isobaric molecular structures without losing any fraction of the samples, as is often the case in heart cutting approaches. Additionally, this solution is not associated with any extension of the measurement time. The assignment of the substance pattern to distinct species is improved as compared to solely using mass spectrometry without a preceding separation step. Furthermore, hitherto undetected compounds have been found in the evolved gases from the thermal degradation of ABS. Finally, a first estimation of the limit of detection has been carried out. This results in a significant decrease of the LOD in case of TG-GCxSPIMS (500 ppt for toluene) as compared to 30 ppb, which could be reached with TG-SPIMS.
18. Single thrombopoietin dose alleviates hematopoietic stem cells intrinsic short- and long-term ionizing radiation damage. In vivo identification of anatomical cell expansion sites.
Science.gov (United States)
Tronik-Le Roux, Diana; Nicola, Marie-Anne; Vaigot, Pierre; Nurden, Paquita
2015-01-01
Hematopoietic stem cells (HSC) are essential for maintaining the integrity of complex and long-lived organisms. HSC, which are self-renewing, reconstitute the hematopoietic system through out life and facilitate long-term repopulation of myeloablated recipients. We have previously demonstrated that when mice are exposed to sublethal doses of ionizing radiation, subsets of the stem/progenitor compartment are affected. In this study we examine the role of thrombopoietin (TPO) on the regenerative capacities of HSC after irradiation and report the first demonstration of efficacy of a single injection of TPO shortly after in vivo exposure to ionizing radiation for reducing HSC injury and improving their functional outcome. Our results demonstrate that TPO treatment not only reduced the number of apoptotic cells but also induced a significant modification of their intrinsic characteristics. These findings were supported by transplantation assays with long-term HSC that were irradiated or unirradiated, TPO treated or untreated, in CD45.1/CD45.2 systems and by using luciferase-labeled HSC for direct bioluminescence imaging in living animals. Of particular importance, our data demonstrate the skull to be a highly favorable site for the TPO-induced emergence of hematopoietic cells after irradiation, suggesting a TPO-mediated relationship of primitive hematopoietic cells to an anatomical component. Together, the data presented here: provide novel findings about aspects of TPO action on stem cells, open new areas of investigation for therapeutic options in patients who are treated with radiation therapy, and show that early administration of a clinically suitable TPO-agonist counteracts the previously observed adverse effects.
19. Substoichiometric extraction of phosphorus
International Nuclear Information System (INIS)
Shigematsu, T.; Kudo, K.
1981-01-01
A study of the substoichiometric extraction of phosphorus is described. Phosphorus was extracted in the form of ternary compounds such as ammonium phosphomolybdate, 8-hydroxyquinolinium phosphomolybdate, tetraphenylarsonium phosphomolybdate and tri-n-octylamine phosphomolybdate. Consequently, phosphorus was extracted substoichiometrically by the addition of a substoichiometric amount of molybdenum for the four phosphomolybdate compounds. On the other hand, phosphorus could be separated substoichiometrically with a substoichiometric amount of tetraphenylarsonium chloride or tri-n-octylamine. Stoichiometric ratios of these ternary compounds obtained substoichiometrically were 1:12:3 for phosphorus, molybdenum and organic reagent. The applicability of these compounds to phosphorus determination is also discussed. (author)
International Nuclear Information System (INIS)
Westin, J.B.
1987-01-01
Accidents at nuclear power facilities seem inevitably to bring in their wake a great deal of concern on the part of both the lay and medical communities. Relatively little attention, however, is given to what may be the largest single worldwide source of effectively carcinogenic ionizing radiation: tobacco. The risk of cancer deaths from the Chernobyl disaster are tobacco smoke is discussed
1. Ionization chambers
International Nuclear Information System (INIS)
Boag, J.W.
1987-01-01
Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed
2. Collisional ionization
International Nuclear Information System (INIS)
Arnaud, M.
1985-07-01
In low density, thin plasmas (such as stellar coronae, interstellar medium, intracluster medium) the ionization process is governed by collision between electrons and ions in their ground state. In view of the recent improvements we thought an updating of ionization rates was really needed. The work is based on both experimental data and theoretical works and give separate estimates for the direct and autoionization rates
3. Phosphorus blood test
Science.gov (United States)
... page: //medlineplus.gov/ency/article/003478.htm Phosphorus blood test To use the sharing features on this page, please enable JavaScript. The phosphorus blood test measures the amount of phosphate in the blood. ...
4. Phosphorus determination by various substoichiometric methods
International Nuclear Information System (INIS)
Shigematsu, Toshio; Kudo, Kiyoshi
1981-01-01
Various substoichiometric methods have been classified from a view point of the substoichiometric separation. Based upon the substoichiometric separation, phosphorus was determined substoichiometrically by a direct method, a method of carrier amount variation and a comparison method for the irradiated sample. The direct method was applied to the determination of phosphorus in orchard leaves (SRM-1571). The analytical value was 0.23 +- 0.01%. Phosphorus in orchard leaves and spinach (SRM-1570) was determined by an ordinary method which devided the sample into equal parts in the method of carrier amount variation. Analytical values of orchard leaves and spinach were 0.22 +- 0.02% and 0.56 +- 0.04%, respectively. Moreover, a new modification of the method of carrier amount variation was studied by the use of various standard samples such as red phosphorus, spinach and orchard leaves. These standard samples were also employed for the determination of phosphorus in orchard leaves and 0.21 +- 0.01% was obtained. All these results are in good agreement with the value reported by NBS. The comparison method was applied to the determination of phosphorus in a semiconductor silicon single crystal. As a result of the correction of 32 P activity induced by the secondary nuclear reaction of 30 Si, 7.9 ppb and 3.1 ppb were obtained for the phosphorus concentrations in the single crystal silicon. (author)
5. Laser Induced Fluorescence (LIF) Measurements of Neutral (ArI) and singly-ionized (ArII) Argon in a LargeScale Helicon Plasma
Science.gov (United States)
Kelly, R. F.; Fisher, D. M.; Hatch, M. W.; Gilmore, M.; Dwyer, R. H.; Meany, K.; Zhang, Y.; Desjardins, T. R.
2017-10-01
In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, a Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable diode laser with a tuning range between 680 and 700nm. For neutral Argon, the laser pumps the metastable (2P3/20) 4s level to the (2P1/20) 4p level using 696. 7352 nm light. The fluorescence radiation from decay to the (2P1/20) 4s level at 772. 6333 nm is observed. For singly ionized Argon, the laser pumps the 3s23p4(3 P)3d level to the 3s23p4(3 P)4p level using 686.3162nm light. The fluorescence radiation from the decay to the 3s23p4(3 P)4s level is observed. The system design, and velocity measurements in the axial, azimuthal and radial directions for ArI, and in the axial direction for ArII will be presented. Supported by U.S. National Science Foundation Award 1500423.
6. Phosphorus use efficiency of maize: an investigation using radiotracer phosphorus (32P)
International Nuclear Information System (INIS)
Meena, S.
2017-01-01
A better understanding on the nutrient uptake and utilization by plants is essential for developing better nutrient efficient cultivars suited for optimal production. Precise information on the PUE of crops and P dynamics can be obtained with the help of radiotracer technique. To study the phosphorus acquisition and phosphorus use efficiency of added sources in maize using 32 P, a pot culture experiment was conducted in a medium P soil (21.26 kg ha -1 ). The treatments were P as Single Superphosphate, Enriched FYM with Single Superphosphate (EFYM), DAP, Nutriseed pack (SSP), Nutriseed pack (DAP). The above treatments were applied along with phosphobacteria. Totally there were ten treatments replicated four times. Phosphorus sources were tagged with 32 P (obtained as 32 P in orthophosphoric medium from the Board of Radiation and Isotope Technology) and applied as per the treatments. Radioactive 32 P in the grain and stover sample was determined using Liquid Scintillation Counter (Perkin Elmer Tricarb 2810 R). Using the data, per cent phosphorus derived from fertilizer (%Pdff), per cent phosphorus derived from soil (%Pdfs), Phosphorus Use Efficiency (PUE) and A value were determined. Application of Phosphorus (SSP, DAP, enriched FYM with SSP, Nutriseed pack (SSP) and Nutriseed pack (DAP)) along with PB increased the per cent phosphorus derived from fertilizer (% Pdff), P uptake from fertilizer and PUE. The highest PUE of 25.38 was recorded in the treatment where enriched FYM with SSP was applied along with PB. (author)
7. Determination of residual 1,4-dioxane in surfactants and cleaning agents using headspace single-drop microextraction followed by gas chromatography-flame ionization detection.
Science.gov (United States)
Saraji, M; Shirvani, N
2017-02-01
Polyethoxylated surfactants are widely used in the formulation of different cleaning agents such as shampoo, dish washing and hand washing products and lotion formulation. During the production of polyethoxylated surfactants, 1,4-dioxane as a toxic and carcinogenic by-product is formed. A simple low-cost method based on headspace single-drop microextraction combined with gas chromatography-flame ionization detection was developed for the determination of 1,4-dioxane in surfactants and cleaning agents. In this method, 1,4-dioxane was extracted from 8.0 mL sample solution into a microdrop of an organic solvent, and then, it was injected to gas chromatography. The effects of such parameters as the solvent type, salt addition, microdrop volume, stirring rate, equilibrium time, extraction time and the temperature of sample solution on the extraction performance were studied and optimized. An ethoxylated surfactant containing 1,4-dioxane was used as the sample for the optimization of the extraction parameters. The linear range, determination coefficient, limit of detection and relative standard deviation of the method were 0.5-100 μg g -1 , 0.9977, 0.4 μg g -1 and 7.2% (n = 5), respectively. Different real samples including sodium lauryl ether sulphate, sodium lauryl sulphate (SLS), four brands of shampoo, and hand washing and dish washing liquids were analysed by the method. 1,4-Dioxane was detected at the concentration range of 2.4-201 μg g -1 in the samples, except dish washing liquid and SLS. A new method with the merits of simplicity, low cost, low organic solvent consumption, short analysis time, good repeatability and suitable detection limit was developed for the analysis of 1,4-dioxane in surfactants and cleaning agents. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
8. A single-electron picture based on the multiconfiguration time-dependent Hartree-Fock method: application to the anisotropic ionization and subsequent high-harmonic generation of the CO molecule
Science.gov (United States)
Ohmura, S.; Kato, T.; Oyamada, T.; Koseki, S.; Ohmura, H.; Kono, H.
2018-02-01
The mechanisms of anisotropic near-IR tunnel ionization and high-order harmonic generation (HHG) in a CO molecule are theoretically investigated by using the multiconfiguration time-dependent Hartree-Fock (MCTDHF) method developed for the simulation of multielectron dynamics of molecules. The multielectron dynamics obtained by numerically solving the equations of motion (EOMs) in the MCTDHF method is converted to a single orbital picture in the natural orbital representation where the first-order reduced density matrix is diagonalized. The ionization through each natural orbital is examined and the process of HHG is classified into different optical paths designated by a combinations of initial, intermediate and final natural orbitals. The EOMs for natural spin-orbitals are also derived within the framework of the MCTDHF, which maintains the first-order reduced density matrix to be a diagonal one throughout the time propagation of a many-electron wave function. The orbital dependent, time-dependent effective potentials that govern the dynamics of respective time-dependent natural orbitals are deduced from the derived EOMs, of which the temporal variation can be used to interpret the motion of the electron density associated with each natural spin-orbital. The roles of the orbital shape, multiorbital ionization, linear Stark effect and multielectron interaction in the ionization and HHG of a CO molecule are revealed by the effective potentials obtained. When the laser electric field points to the nucleus O from C, tunnel ionization from the C atom side is enhanced; a hump structure originating from multielectron interaction is then formed on the top of the field-induced distorted barrier of the HOMO effective potential. This hump formation, responsible for the directional anisotropy of tunnel ionization, restrains the influence of the linear Stark effect on the energy shifts of bound states.
9. Agricultural phosphorus legislation in Europe
NARCIS (Netherlands)
Amery, F.; Schoumans, O.F.
2014-01-01
Phosphorus (P) losses from agricultural fields can cause eutrophication and ecological deterioration of surface waters. Although there is no general European Phosphorus Regulation or Directive, some European Member States address the agricultural phosphorus losses via national or regional
10. A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg
Science.gov (United States)
Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor
2014-01-01
Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.
11. Resonance Ionization Laser Ion Sources
CERN Document Server
Marsh, B
2013-01-01
The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...
12. Phosphorus dendrimers for nanomedicine.
Science.gov (United States)
2017-08-31
From biomaterials to imaging, and from drug delivery to drugs by themselves, phosphorus-containing dendrimers offer a large palette of biological properties, depending essentially on their types of terminal functions. The most salient examples of phosphorus dendrimers used for the elaboration of bio-chips and of supports for cell cultures, for imaging biological events, and for carrying and delivering drugs or biomacromolecules are presented in this feature article. Several phosphorus dendrimers can be considered also as drugs per se (by themselves) in particular to fight against cancers, neurodegenerative diseases, and inflammation, both in vitro and in vivo. Toxicity assays are also reported.
13. Phosphorus, phosphorous, and phosphate.
Science.gov (United States)
Iheagwara, O Susan; Ing, Todd S; Kjellstrand, Carl M; Lew, Susie Q
2013-10-01
This article distinguishes the terms "phosphorus, phosphorous, and phosphate" which are frequently used interchangeably. We point out the difference between phosphorus and phosphate, with an emphasis on the unit of measure. Expressing a value without the proper name or unit of measure may lead to misunderstanding and erroneous conclusions. We indicate why phosphate must be expressed as milligrams per deciliter or millimoles per liter and not as milliequivalents per liter. Therefore, we elucidate the distinction among the terms "phosphorus, phosphorous, and phosphate" and the importance of saying precisely what one really means. © 2012 The Authors. Hemodialysis International © 2012 International Society for Hemodialysis.
14. Label-free Quantification of Proteins in Single Embryonic Cells with Neural Fate in the Cleavage-Stage Frog (Xenopus laevis) Embryo using Capillary Electrophoresis Electrospray Ionization High-Resolution Mass Spectrometry (CE-ESI-HRMS).
Science.gov (United States)
Lombard-Banek, Camille; Reddy, Sushma; Moody, Sally A; Nemes, Peter
2016-08-01
Quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. Using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (Xenopus laevis) embryo. In this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (LFQ) for single Xenopus cells. The technology builds on a custom-designed capillary electrophoresis microflow-electrospray ionization high-resolution mass spectrometry platform and LFQ by MaxLFQ (MaxQuant). By judiciously tailoring performance to peptide separation, ionization, and data-dependent acquisition, we demonstrate an ∼75-amol (∼11 nm) lower limit of detection and quantification for proteins in complex cell digests. The platform enabled the identification of 438 nonredundant protein groups by measuring 16 ng of protein digest, or embryo. LFQ intensity was validated as a quantitative proxy for protein abundance. Correlation analysis was performed to compare protein quantities between the embryo and n = 3 different single D11 blastomeres, which are fated to develop into the nervous system. A total of 335 nonredundant protein groups were quantified in union between the single D11 cells spanning a 4 log-order concentration range. LFQ and correlation analysis detected expected proteomic differences between the whole embryo and blastomeres, and also found translational differences between individual D11 cells. LFQ on single cells raises exciting possibilities to study gene expression in other cells and models to help better understand cell processes on a systems biology level. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
15. Label-free Quantification of Proteins in Single Embryonic Cells with Neural Fate in the Cleavage-Stage Frog (Xenopus laevis) Embryo using Capillary Electrophoresis Electrospray Ionization High-Resolution Mass Spectrometry (CE-ESI-HRMS)*
Science.gov (United States)
Lombard-Banek, Camille; Reddy, Sushma; Moody, Sally A.; Nemes, Peter
2016-01-01
Quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. Using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (Xenopus laevis) embryo. In this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (LFQ) for single Xenopus cells. The technology builds on a custom-designed capillary electrophoresis microflow-electrospray ionization high-resolution mass spectrometry platform and LFQ by MaxLFQ (MaxQuant). By judiciously tailoring performance to peptide separation, ionization, and data-dependent acquisition, we demonstrate an ∼75-amol (∼11 nm) lower limit of detection and quantification for proteins in complex cell digests. The platform enabled the identification of 438 nonredundant protein groups by measuring 16 ng of protein digest, or embryo. LFQ intensity was validated as a quantitative proxy for protein abundance. Correlation analysis was performed to compare protein quantities between the embryo and n = 3 different single D11 blastomeres, which are fated to develop into the nervous system. A total of 335 nonredundant protein groups were quantified in union between the single D11 cells spanning a 4 log-order concentration range. LFQ and correlation analysis detected expected proteomic differences between the whole embryo and blastomeres, and also found translational differences between individual D11 cells. LFQ on single cells raises exciting possibilities to study gene expression in other cells and models to help better understand cell processes on a systems biology level. PMID:27317400
International Nuclear Information System (INIS)
2009-01-01
After having recalled some fundamental notions and measurement units related to ionizing radiations, this document describes various aspects of natural and occupational exposures: exposure modes and sources, exposure levels, biological effects, health impacts. Then, it presents prevention principles aimed at, in an occupational context of use of radiation sources (nuclear industry excluded), reducing and managing these exposures: risk assessment, implementation of safety from the front end. Some practical cases illustrate the radiation protection approach. The legal and regulatory framework is presented: general notions, worker exposure, measures specific to some worker categories (pregnant and breast feeding women, young workers, temporary workers). A last part describes what is to be done in case of incident or accident (dissemination of radioactive substances from unsealed sources, anomaly occurring when using a generator or a sealed source, post-accident situation)
17. Anomalous superconductivity in black phosphorus under high pressures
International Nuclear Information System (INIS)
Kawamura, H.; Tachikawa, K.
1984-01-01
Pressure induced superconductivity in single crystals of black phosphorus has been studied. Maximum onset Tsub(c) was near 13 K. The anomalous superconductivity may be explained in terms of excitonic mechanism. (author)
18. Isotopically exchangeable phosphorus
International Nuclear Information System (INIS)
Barbaro, N.O.
1984-01-01
A critique revision of isotope dilution is presented. The concepts and use of exchangeable phosphorus, the phosphate adsorption, the kinetics of isotopic exchange and the equilibrium time in soils are discussed. (M.A.C.) [pt
19. Multiple chamber ionization detector
International Nuclear Information System (INIS)
Solomon, E.E.
1982-01-01
An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector
20. Photoluminescence study of novel phosphorus-doped ZnO nanotetrapods synthesized by chemical vapour deposition
International Nuclear Information System (INIS)
Yu Dongqi; Hu Lizhong; Qiao Shuangshuang; Zhang Heqiu; Fu Qiang; Chen Xi; Sun Kaitong; Len, Song-En Andy; Len, L K
2009-01-01
Novel phosphorus-doped and undoped single crystal ZnO nanotetrapods were fabricated on sapphire by a simple chemical vapour deposition method, using phosphorus pentoxide (P 2 O 5 ) as the dopant source. The optical properties of the samples were investigated by photoluminescence (PL) spectroscopy. Low-temperature PL measurements of phosphorus-doped and undoped samples were compared, and the results indicated a decrease in deep level defects due to the incorporation of a phosphorus acceptor dopant. The PL spectrum of the phosphorus-doped sample at 10 K exhibited several acceptor-bound exciton related emission peaks. The effect of phosphorus doping on the optical characteristics of the samples was investigated by excitation intensity and temperature dependent PL spectra. The acceptor-binding energies of the phosphorus dopant were estimated to be about 120 meV, in good agreement with the corresponding theoretical and experimental values in phosphorus-doped ZnO films and nanowires.
1. Effect of phosphorus level on nitrogen accumulation and yield in soybean
International Nuclear Information System (INIS)
You Yubo; Wu Dongmei; Gong Zhenping; Ma Chunmei
2012-01-01
In this paper, the 15 N labeling with sand culture was conducted to study effects of phosphorus level on nitrogen accumulation, nodule nitrogen fixation and yield of soybean plants. Results showed that nitrogen accumulation, fixation and yield of soybean plants all presented a single peak curve with improvement of phosphorus nutrition level, with the peak value of phosphorus concentration in nutrient solution of 31 mg/L. When phosphorus concentration of nutrient solution was 11 mg/L, no obvious promotion was found on the ratio of nodule nitrogen fixation when increasing phosphorus concentration again, However, when phosphorus concentration of nutrient solution was 21 mg/L, increasing phosphorus concentration again had no obvious promotion on soybean plant nitrogen accumulation, nodule nitrogen fixation accumulation and yield, indicating that effect of phosphorus nutrition level on nitrogen fixation was lower than that on yield formation level. (authors)
2. Single photon simultaneous K-shell ionization and K-shell excitation. I. Theoretical model applied to the interpretation of experimental results on H2O
International Nuclear Information System (INIS)
Carniato, S.; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P.; Žitnik, M.; Bučar, K.; Nakano, M.; Hikosaka, Y.; Ito, K.
2015-01-01
We present in detail a theoretical model that provides absolute cross sections for simultaneous core-ionization core-excitation (K −2 V ) and compare its predictions with experimental results obtained on the water molecule after photoionization by synchrotron radiation. Two resonances of different symmetries are assigned in the main K −2 V peak and comparable contributions from monopolar (direct shake-up) and dipolar (conjugate shake-up) core-valence excitations are identified. The main peak is observed with a much greater width than the total experimental resolution. This broadening is the signature of nuclear dynamics
3. Organic chemistry of elemental phosphorus
International Nuclear Information System (INIS)
Milyukov, V A; Budnikova, Yulia H; Sinyashin, Oleg G
2005-01-01
The principal achievements and the modern trends in the development of the chemistry of elemental phosphorus are analysed, described systematically and generalised. The possibilities and advantages of the preparation of organophosphorus compounds directly from white phosphorus are demonstrated. Attention is focused on the activation and transformation of elemental phosphorus in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white phosphorus with nucleophilic and electrophilic reagents are discussed. Electrochemical approaches to the synthesis of organic phosphorus derivatives based on white phosphorus are considered.
4. Preparation of phosphorus targets using the compound phosphorus nitride
International Nuclear Information System (INIS)
Maier-Komor, P.
1987-01-01
Commercially available phosphorus nitride (P 3 N 5 ) shows a high oxygen content. Nevertheless, this material is attractive for use as phosphorus targets in experiments where red phosphorus would disappear due to its high vapor pressure and where a metal partner in the phosphide must be excluded due to its high atomic number. Methods are described to produce phosphorus nitride targets by vacuum evaporation condensation. (orig.)
5. Regiospecific analysis of neutral ether lipids by liquid chromatography/electrospray ionization/single quadrupole mass spectrometry: validation with synthetic compounds
DEFF Research Database (Denmark)
Hartvigsen, Karsten; Ravandi, A.; Bukhave, Klaus
2001-01-01
A reversed-phase high-performance liquid chromatography (HPLC) method with on-line electrospray ionization/collision-induced dissociation/mass spectrometry (ESI/CID/MS) is presented for the regiospecific analysis of synthetic reference compounds of neutral ether lipids. The reference compounds were....... The diagnostic ions of directly analyzed 1-O-alkyl-2,3-diacyl-sn- glycerols were the [M - alkyl](+), [M - sn-2-acyl](+) and [M - sn-3-acyl](+) ions. Regiospecific characterization of the fatty acid identity and position was evident from the relative ion intensities, as fragmentation of the sn-2 fatty acids...... for each neutral ether lipid class. The present study demonstrates that reversed-phase HPLC and positive ion ESI/CID/MS provide direct and unambiguous information about the configuration and identity of molecular species in neutral 1-O-alkyl-sn-glycerol classes....
6. III. Quantitative aspects of phosphorus excretionin ruminants
OpenAIRE
Bravo , David; Sauvant , Daniel; Bogaert , Catherine; Meschy , François
2003-01-01
International audience; Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva secretion (DM intake, physical dietary characteristics and dietary phosphorus...
7. phosphorus retention data and metadata
Data.gov (United States)
U.S. Environmental Protection Agency — phosphorus retention in wetlands data and metadata. This dataset is associated with the following publication: Lane , C., and B. Autrey. Phosphorus retention of...
International Nuclear Information System (INIS)
Montoya, Nawer D; Villegas, Wilson E; Rodriguez, Lino M; Taborda, Nelson; Montes de C, Consuelo
2001-01-01
Several AL 2 O 3 supported oxides such as: NiO, CuO, Co 2 O 3 BaO, CeO 2 and ZnO were investigated for phosphorus adsorption. Zno/y-Al 2 O 3 exhibited the highest phosphorus adsorption capacity. However, since it diminishes the activity of to the reaction mixture it should be located upstream of the NoX catalyst, i.e. 0,3% Pd-H-MOR, in order to protect it against p poisoning. The treatment procedure with citric acid was effective for the removal of more than 70% phosphorus from the adsorbent, ZnO/y-Al 2 O 3
9. Chromatography of phosphorus oxoacids
International Nuclear Information System (INIS)
The present state of studies on the chromatographic separation of phosphorus oxoacids is surveyed. In this paper, chromatographic techniques are divided into four groups, i.e. paper and thin-layer chromatography, paper electrophoresis, ion-exchange chromatography, and gel chromatography. The separation mechanisms and characteristics for these chromatographic methods are discussed and some examples for the separation of phosphorus oxoacids are described. As examples of the application of ion-exchange and gel chromatography, studies on the hot atom chemistry of 32 P in solid inorganic phosphates and those on the substitution reactions between diphosphonate (diphosphite) and polyphosphates are reported. (author)
10. Phosphorus in Agriculture : 100 % Zero
NARCIS (Netherlands)
Schnug, Ewald; De Kok, Luit J.
2016-01-01
Phosphorus is essential for all living organisms, reserves in geogenic deposits are finite, and phosphorus nutrient mining and oversupply are common phenomenons on agricultural soils. Only if the agricultural phosphorus cycle can be closed and the fertilized nutrient been utilized completely,
11. Size dependence of the polarizability and Haynes rule for an exciton bound to an ionized donor in a single spherical quantum dot
Energy Technology Data Exchange (ETDEWEB)
Feddi, E., E-mail: [email protected]; Zouitine, A. [Université Mohamed V Souissi, Ecole Normale Supérieure de l' Enseignement Technique (ENSET), Rabat (Morocco); Oukerroum, A.; Zazoui, M. [Laboratory of Condensed Matter, Faculty of Sciences and Techniques, University of Hassan II-Mohammedia, B.P. 146, 20800 Mohammedia (Morocco); Dujardin, F. [LCP-A2MC, Université de Lorraine, ICPM, 1 Bd Arago, 57070 Metz (France); Assaid, E. [Laboratoire d' Électronique et Optique des Nanostructures de Semiconducteurs, Faculté des Sciences, B. P. 20, El Jadida (Morocco)
2015-02-14
We study the effect of an external electric field on an exciton bound to an ionized donor (D{sup +}, X) confined in a spherical quantum dot using a perturbative-variational method where the wave function and energy are developed in series of powers of the electric field strength. After testing this new approach in the determination of the band gap for some semiconductor materials, we generalize it to the case of (D{sup +}, X) in the presence of the electric field and for several materials ZnO, PbSe, and InAs, with significant values of the mass ratio. Three interesting results can be deduced: First, we show that the present method allows to determine the ground state energy in the presence of a weak electric field in a simple way (E = E{sub 0} − αf{sup 2}) using the energy without electric field E{sub 0} and the polarizability α. The second point is that our theoretical predictions show that the polarizability of (D{sup +}, X) varies proportionally to R{sup 3.5} and follows an ordering α{sub D{sup 0}}<α{sub X}<α{sub (D{sup +},X)}. The last point to highlight is that the Haynes rule remains valid even in the presence of a weak electric field.
12. Plasma concentration of ionized calcium in healthy iguanas.
Science.gov (United States)
Dennis, P M; Bennett, R A; Harr, K E; Lock, B A
2001-08-01
To measure plasma concentration of ionized calcium in healthy green iguanas. Prospective study. 9 juvenile and 21 (10 male, 11 female) adult iguanas. Blood samples were obtained from each iguana, and plasma calcium, glucose, phosphorus, uric acid, total protein, albumin, globulin, potassium, and ionized calcium concentrations, aspartate transaminase (AST) activity, and pH were measured. Heparinized blood was used for measurement of ionized calcium concentration and blood pH. A CBC was also performed to assess the health of the iguanas. Significant differences were not detected among the 3 groups (juveniles, males, and females) with regard to ionized calcium concentration. Mean ionized calcium concentration measured in blood was 1.47 +/- 0.105 mmol/L. Significant differences were detected between juveniles and adults for values of phosphorus, glucose, total protein, albumin, globulin, and AST activity. Ionized calcium concentration provides a clinical measurement of the physiologically active calcium in circulation. Evaluation of physiologically active calcium in animals with suspected calcium imbalance that have total plasma calcium concentrations within reference range or in gravid animals with considerably increased total plasma calcium concentrations is vital for determining a therapeutic plan. Accurate evaluation of calcium status will provide assistance in the diagnosis of renal disease and seizures and allow for better evaluation of the health status of gravid female iguanas.
13. Phosphorus-nitrogen compounds
Home; Journals; Journal of Chemical Sciences; Volume 120; Issue 4. Phosphorus-nitrogen compounds: Part 15. Synthesis, anisochronism and the relationship between crystallographic and spectral data of monotopic spiro-crypta phosphazenes. Nuran Asmafi̇li̇z Eli̇f Ece İl Ter Zeynel Kiliç Tuncer Hökelek Ertan Şahin.
14. Phosphorus control in peritoneal dialysis patients.
Science.gov (United States)
Yavuz, A; Ersoy, F F; Passadakis, P S; Tam, P; Evaggelos, D M; Katopodis, K P; Ozener, C; Akçiçek, F; Camsari, T; Ateş, K; Ataman, R; Vlachojannis, G J; Dombros, N A; Utaş, C; Akpolat, T; Bozfakioğlu, S; Wu, G; Karayaylali, I; Arinsoy, T; Stathakis, C P; Yavuz, M; Tsakiris, D J; Dimitriades, A C; Yilmaz, M E; Gültekin, M; Süleymanlar, G; Oreopoulos, D G
2008-04-01
Hyperphosphatemia is independently associated with an increased risk of death among dialysis patients. In this study, we have assessed the status of phosphate control and its clinical and laboratory associations in a large international group of patients on chronic peritoneal dialysis (PD) treatment. This cross-sectional multicenter study was carried out in 24 centers in three different countries (Canada, Greece, and Turkey) among 530 PD patients (235 women, 295 men) with a mean+/-s.d. age of 55+/-16 years and mean duration of PD of 33+/-25 months. Serum calcium (Ca(2+)), ionized Ca(2+), phosphate, intact parathyroid hormone (iPTH), 25-hydroxy vitamin D(3), 1,25-dihydroxy vitamin D(3), total alkaline phosphatase, and bone alkaline phosphatase concentrations were investigated, along with adequacy parameters such as Kt/V, weekly creatinine clearance, and daily urine output. Mean Kt/V was 2.3+/-0.65, weekly creatinine clearance 78.5+/-76.6 l, and daily urine output 550+/-603 ml day(-1). Fifty-five percent of patients had a urine volume of phosphorus level was 4.9+/-1.3 mg per 100 ml, serum Ca(2+) 9.4+/-1.07 mg per 100 ml, iPTH 267+/-356 pg ml(-1), ionized Ca(2+) 1.08+/-0.32 mg per 100 ml, calcium phosphorus (Ca x P) product 39+/-19 mg(2)dl(-2), 25(OH)D(3) 8.3+/-9.3 ng ml(-1), 1,25(OH)(2)D(3) 9.7+/-6.7 pg ml(-1), total alkaline phosphatase 170+/-178 U l(-1), and bone alkaline phosphatase 71+/-108 U l(-1). While 14% of patients were hypophosphatemic, with a serum phosphorus level lower than 3.5 mg per 100 ml, most patients (307 patients, 58%) had a serum phosphate level between 3.5 and 5.5 mg per 100 ml. Serum phosphorus level was 5.5 mg per 100 ml or greater in 28% (149) of patients. Serum Ca(2+) level was > or =9.5 mg per 100 ml in 250 patients (49%), between 8.5 and 9.5 mg per 100 ml in 214 patients (40%), and lower than 8.5 mg per 100 ml in 66 patients (12%). Ca x P product was >55 mg(2)dl(-2) in 136 patients (26%) and lower than 55 mg(2)dl(-2) in 394 patients (74
15. Determination of phosphorus in gold or silver brazing alloys
International Nuclear Information System (INIS)
Antepenko, R.J.
1976-01-01
A spectrophotometric method has been devised for measuring microgram levels of phosphorus in brazing alloys of gold or silver alloys is normally measured by solid mass spectrometry, but the high nickel concentration produces a double ionized nickel spectral interference. The described procedures is based upon the formation of molybdovandophosphoric acid when a molybdate solution is added to an acidic solution containing orthophosphate and vanadate ions. The optimum acidity for forming the yellow colored product is 0.5 N hydrochloric acid. The working concentration range is from 0.1 to 1 ppm phosphorus using 100-mm cells and measuring the absorbance at 460 nm. The sample preparation procedure employs aqua regia to dissolve the alloy oxidize the phosphorus to orthophosphate. Cation-exchange chromatography is used to remove nickel ions and anion-exchange and chromatography to remove gold ions as the chloride complex. Excellent recoveries are obtained for standard phosphorus solutions run through the sample procedure. The procedure is applicable to a variety of gold or silver braze alloys requiring phosphorus analysis
16. Black phosphorus saturable absorber for ultrashort pulse generation
Energy Technology Data Exchange (ETDEWEB)
Sotor, J., E-mail: [email protected]; Sobon, G.; Abramski, K. M. [Laser and Fiber Electronics Group, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370 (Poland); Macherzynski, W.; Paletko, P. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroclaw 50-372 (Poland)
2015-08-03
Low-dimensional materials, due to their unique and versatile properties, are very interesting for numerous applications in electronics and optoelectronics. Recently rediscovered black phosphorus, with a graphite-like layered structure, can be effectively exfoliated up to the single atomic layer called phosphorene. Contrary to graphene, it possesses a direct band gap controllable by the number of stacked atomic layers. For those reasons, black phosphorus is now intensively investigated and can complement or replace graphene in various photonics and electronics applications. Here, we demonstrate that black phosphorus can serve as a broadband saturable absorber and can be used for ultrashort optical pulse generation. The mechanically exfoliated ∼300 nm thick layers of black phosphorus were transferred onto the fiber core, and under pulsed excitation at 1560 nm wavelength, its transmission increases by 4.6%. We have demonstrated that the saturable absorption of black phosphorus is polarization sensitive. The fabricated device was used to mode-lock an Er-doped fiber laser. The generated optical solitons with the 10.2 nm bandwidth and 272 fs duration were centered at 1550 nm. The obtained results unambiguously show that black phosphorus can be effectively used for ultrashort pulse generation with performances similar or even better than currently used graphene or carbon nanotubes. This application of black phosphorus proves its great potential to future practical use in photonics.
17. Ionization potentials of seaborgium
International Nuclear Information System (INIS)
Johnson, E.; Pershina, V.; Fricke, B.
1999-01-01
Multiconfiguration relativistic Dirac-Fock values were calculated for the first six ionization potentials of seaborgium and of the other group 6 elements. No experimental ionization potentials are available for seaborgium. Accurate experimental values are not available for all of the other ionization potentials. Ionic radii for the 4+ through 6+ ions of seaborgium are also presented. The ionization potentials and ionic radii obtained will be used to predict some physiochemical properties of seaborgium and its compounds
18. Ionization of food products
International Nuclear Information System (INIS)
Vasseur, J.P.
1991-01-01
After general remarks on foods preservation, on international works and on ionization future prospects, main irradiation sources are described. Recalls on radioactivity, on radiation-matter interaction, on toxicology of ionized foods and on ionized foods detection are given. Ionization applications to various products are reviewed, especially in: - Poultry meat - Fishing products - Fresh fruits and vegetables - Dry fruits and vegetables - spices, tea, infusion - prepacked products... An evaluation of economics and sociocultural impacts is presented in connection with recent experiments [fr
19. Deviation from Boltzmann distribution in excited energy levels of singly-ionized iron in an argon glow discharge plasma for atomic emission spectrometry
Energy Technology Data Exchange (ETDEWEB)
Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: [email protected]
2012-01-15
A Boltzmann plot for many iron ionic lines having excitation energies of 4.7-9.1 eV was investigated in an argon glow discharge plasma when the discharge parameters, such as the voltage/current and the gas pressure, were varied. A Grimm-style radiation source was employed in a DC voltage range of 400-800 V at argon pressures of 400-930 Pa. The plot did not follow a linear relationship over a wide range of the excitation energy, but it yielded a normal Boltzmann distribution in the range of 4.7-5.8 eV and a large overpopulation in higher-lying excitation levels of iron ion. A probable reason for this phenomenon is that excitations for higher excited energy levels of iron ion would be predominantly caused by non-thermal collisions with argon species, the internal energy of which is received by iron atoms for the ionization. Particular intense ionic lines, which gave a maximum peak of the Boltzmann plot, were observed at an excitation energy of ca. 7.7 eV. They were the Fe II 257.297-nm and the Fe II 258.111-nm lines, derived from the 3d{sup 5}4s4p {sup 6}P excited levels. The 3d{sup 5}4s4p {sup 6}P excited levels can be highly populated through a resonance charge transfer from the ground state of argon ion, because of good matching in the excitation energy as well as the conservation of the total spin before and after the collision. An enhancement factor of the emission intensity for various Fe II lines could be obtained from a deviation from the normal Boltzmann plot, which comprised the emission lines of 4.7-5.8 eV. It would roughly correspond to a contribution of the charge transfer excitation to the excited levels of iron ion, suggesting that the charge-transfer collision could elevate the number density of the corresponding excited levels by a factor of ca.10{sup 4}. The Boltzmann plots give important information on the reason why a variety of iron ionic lines can be emitted from glow discharge plasmas.
20. Substoichiometric determination of phosphorus
International Nuclear Information System (INIS)
Shigematsu, T.; Kudo, K.
1981-01-01
Phosphorus in orchard leaves (NBS SRM-1571) and spinach (SRM-1570) was determined by various substoichiometric analytical methods such as the direct method, Gravshchenko's method and the method of carrier amount variation. All samples were labelled with 32 P radioisotope. The data obtained by the method of carrier amount variation were also treated by the method of least squares instead of De Voe's method. Phosphorus concentration in orchard leaves was 0.206+-0.011% by the direct method, 0.219+-0.011% by Gravshchenko's method, 0.211+-0.011% by the method of carrier amount variation and 0.207+-0.007% by the method of least squares, respectively. These values agree with the value reported by NBS (0.21+-0.01%). Furthermore, these concentrations obtained by various substoichiometric methods were compared with those by radioactivation reported in a previous paper. (author)
1. Ultraviolet laser desorption/ionization mass spectrometry of single-core and multi-core polyaromatic hydrocarbons under variable conditions of collisional cooling: insights into the generation of molecular ions, fragments and oligomers.
Science.gov (United States)
Gámez, Francisco; Hortal, Ana R; Martínez-Haya, Bruno; Soltwisch, Jens; Dreisewerd, Klaus
2014-11-01
The ultraviolet laser desorption/ionization of polyaromatic hydrocarbons (PAHs) has been investigated under different background pressures of an inert gas (up to 1.2 mbar of N2) in the ion source of a hybrid, orthogonal-extracting time-of-flight mass spectrometer (oTOF-MS). The study includes an ensemble of six model PAHs with isolated single polyaromatic cores and four ones with multiple cross-linked aromatic and polyaromatic cores. In combination with a weak ion extraction field, the variation of the buffer gas pressure allowed to control the degree of collisional cooling of the desorbed PAHs and, thus, to modulate their decomposition into fragments. The dominant fragmentation channels observed are related to dehydrogenation of the PAHs, in most cases through the cleavage of even numbers of C-H bonds. Breakage of C-C bonds leading to the fragmentation of rings, side chains and core linkages is also observed, in particular, at low buffer gas pressures. The precise patterns of the combined fragmentation processes vary significantly between the PAHs. The highest abundances of molecular PAH ions and cleanest mass spectra were consistently obtained at the highest buffer gas pressure of 1.2 mbar. The effective quenching of the fragmentation pathways at this elevated pressure improves the sensitivity and data interpretation for analytical applications, although the fragmentation of side chains and of bonds between (poly)aromatic cores is not completely suppressed in all cases. Moreover, these results suggest that the detected fragments are generated through thermal equilibrium processes rather than as a result of rapid photolysis. This assumption is further corroborated by a laser desorption/ionization post-source decay analysis using an axial time-of-flight MS. In line with these findings, covalent oligomers of the PAHs, which are presumably formed by association of two or more dehydrogenated fragments, are detected with higher abundances at the lower buffer gas
2. Multiple ionization of atoms by ion impact
International Nuclear Information System (INIS)
DuBois, R.D.
1988-01-01
In order to model the energy deposition of fast ions as they slow down in gaseous media, information about the ionization occurring in collisions between ions and target atoms/molecules is required. Our measurements of doubly differential electron emission cross sections provide detailed information about the ionization process but do not provide any information about the final states of the target. They also do not distinguish between the emission of one or more target electrons in a single collision. It is important to know the relative importance of multiple-, with respect to single-, target ionization in order to accurately model the energy deposition. To date, multiple ionization of He, Ne, Ar, Kr, and Xe targets has been studied. Primarily, H and He ions were used, although some data for heavier ions (C,N and O) have also been obtained
Directory of Open Access Journals (Sweden)
Süleyman Daşdağ
2010-06-01
Full Text Available The aim of this study is to evaluate the biologic effects of ionizing radiation and relation between medical diagnosticradiation exposure and cancer risk. Many unnecessary ionizing radiation applications are performed in the medicalcenters and hospitals. Therefore the health staff and the patients expose to serious risks of radiation. On the other hand, recently some studies, which suggested relationshipsbetween low dose ionizing radiation and some cancers, have been published. The relationship between low dose ionizing radiation and cancer can be more understandablewhen the stochastic effects of ionizing radiationtake into consideration. This presented review calls attention to the fact that low dose ionizing radiation may be an important factor for increased cancer risk. Therefore,physicians, health workers and patients have to pay maximum attention to avoid hazards of low dose ionizing radiation.
4. Phosphorus containing sintered alloys (review)
International Nuclear Information System (INIS)
Muchnik, S.V.
1984-01-01
Phosphorus additives are considered for their effect on the properties of sintered alloys of different applications: structural, antifriction, friction, magnetic, hard, superhard, heavy etc. Data are presented on compositions and properties of phosphorus-containing materials produced by the powder metallurgy method. Phosphorus is shown to be an effective activator of sintering in some cases. When its concentration in the material is optimal it imparts the material such properties as strength, viscosity, hardness, wear resistance. Problems concerning powder metallurgy of amorphous phosphorus-containing alloys are reported
5. Phosphorus and the dairy cow
OpenAIRE
2003-01-01
The general aim of the present work was to investigate phosphorus balance in the dairy cow, with reference to the amount and source of phosphorus. Furthermore, biochemical bone markers were used to study the bone turnover during the lactation and dry period. Phosphorus is located in every cell of the body and has more known functions than any other mineral element in the animal body. Phosphorus is also an important constituent of milk, and is therefore required in large amounts in a high yiel...
6. Sustainable Phosphorus Measures: Strategies and Technologies for Achieving Phosphorus Security
Directory of Open Access Journals (Sweden)
Stuart White
2013-01-01
Full Text Available Phosphorus underpins the world’s food systems by ensuring soil fertility, maximising crop yields, supporting farmer livelihoods and ultimately food security. Yet increasing concerns around long-term availability and accessibility of the world’s main source of phosphorus—phosphate rock, means there is a need to investigate sustainable measures to buffer the world’s food systems against the long and short-term impacts of global phosphorus scarcity. While the timeline of phosphorus scarcity is contested, there is consensus that more efficient use and recycling of phosphorus is required. While the agricultural sector will be crucial in achieving this, sustainable phosphorus measures in sectors upstream and downstream of agriculture from mine to fork will also need to be addressed. This paper presents a comprehensive classification of all potential phosphorus supply- and demand-side measures to meet long-term phosphorus needs for food production. Examples range from increasing efficiency in the agricultural and mining sector, to technologies for recovering phosphorus from urine and food waste. Such measures are often undertaken in isolation from one another rather than linked in an integrated strategy. This integrated approach will enable scientists and policy-makers to take a systematic approach when identifying potential sustainable phosphorus measures. If a systematic approach is not taken, there is a risk of inappropriate investment in research and implementation of technologies and that will not ultimately ensure sufficient access to phosphorus to produce food in the future. The paper concludes by introducing a framework to assess and compare sustainable phosphorus measures and to determine the least cost options in a given context.
7. One color multi-photon ionization of the Gadolinium atom in near UV region
International Nuclear Information System (INIS)
Kim, Jin Tae; Yi, Jong Hoon; Lhee, Yong Joo; Lee, Jong Min
1999-01-01
We have investigated the states of the gadolinium atom in near ultra-violet (UV) region (∼410 nm) using single photon excitation using resonance ionization mass spectrometry (RIMS). Around 70 transitions among observed 180 single color multi-photon ionization signals have been assigned. Most of the multi-photon processes of the assigned ion signals are through single photon resonant three photon ionization and through two photon resonant three photon ionization. (author)
8. Determination of phosphorus-32 in urine
International Nuclear Information System (INIS)
Eakins, J.D.; Gomm, P.J.; Jackson, S.
1969-01-01
A method for the determination of total phosphorus-32 by direct beta counting of urine is described, together with more sensitive radiochemical procedures for total phosphorus-32 determination and for phosphorus-32 as inorganic phosphate
9. Fast-electron impact ionization of molecular hydrogen: energy and angular distribution of double and single differential cross sections and Young-type interference
Science.gov (United States)
Chatterjee, S.; Kasthurirangan, S.; Kelkar, A. H.; Stia, C. R.; Fojón, O. A.; Rivarola, R. D.; Tribedi, L. C.
2009-03-01
We report the energy and angular distribution of absolute double differential cross sections (DDCSs) of ejected electrons in collisions of 8 keV projectile electrons with molecular hydrogen. The ejected electrons with energy between 1 eV and 400 eV and ejection angles between 30° and 150° are detected. The measured data are compared with the theoretical calculations based on two-effective centre (TEC) model. The first-order interference is derived from the energy distribution of DDCS and the resulting ratio spectra (H2 to 2H) exhibit oscillating behaviour. The signature of first-order interference is also demonstrated in the DDCS spectra as a function of the ejection angle. We have shown that the constructive interference prevails in soft- and binary-collision regions. The single differential cross sections (SDCS) are deduced by integrating the DDCS over the solid angle as well as ejection energy. We demonstrate that the SDCS and corresponding ratio spectra also preserve the signature of interference.
10. Fast-electron impact ionization of molecular hydrogen: energy and angular distribution of double and single differential cross sections and Young-type interference
Energy Technology Data Exchange (ETDEWEB)
Chatterjee, S; Kasthurirangan, S; Kelkar, A H; Tribedi, L C [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Stia, C R; Fojon, O A; Rivarola, R D [Instituto de Fisica Rosario (CONICET-UNR) and Facultad de Ciencias Exactas, IngenierIa y Agrimensura, Universidad Nacional de Rosario, Av Pellegrini 250, 2000 Rosario (Argentina)], E-mail: [email protected]
2009-03-28
We report the energy and angular distribution of absolute double differential cross sections (DDCSs) of ejected electrons in collisions of 8 keV projectile electrons with molecular hydrogen. The ejected electrons with energy between 1 eV and 400 eV and ejection angles between 30 deg. and 150 deg. are detected. The measured data are compared with the theoretical calculations based on two-effective centre (TEC) model. The first-order interference is derived from the energy distribution of DDCS and the resulting ratio spectra (H{sub 2} to 2H) exhibit oscillating behaviour. The signature of first-order interference is also demonstrated in the DDCS spectra as a function of the ejection angle. We have shown that the constructive interference prevails in soft- and binary-collision regions. The single differential cross sections (SDCS) are deduced by integrating the DDCS over the solid angle as well as ejection energy. We demonstrate that the SDCS and corresponding ratio spectra also preserve the signature of interference.
11. phosphorus sorption capacity as a guide for phosphorus availability
African Journals Online (AJOL)
Crop response to phosphorus application is often erratic in most soil types in Sudan. This inconsistent response is believed to be due to the alkaline nature of most soils in the country. Phosphorus adsorption isotherms and buffering capacity are powerful tools for predicting response of different soil types to apply P fertilisers.
12. Phosphorus leaching in relation to soil type and soil phosphorus content.
Science.gov (United States)
Djodjic, Faruk; Börling, Katarina; Bergström, Lars
2004-01-01
Phosphorus losses from arable soils contribute to eutrophication of freshwater systems. In addition to losses through surface runoff, leaching has lately gained increased attention as an important P transport pathway. Increased P levels in arable soils have highlighted the necessity of establishing a relationship between actual P leaching and soil P levels. In this study, we measured leaching of total phosphorus (TP) and dissolved reactive phosphorus (DRP) during three years in undisturbed soil columns of five soils. The soils were collected at sites, established between 1957 and 1966, included in a long-term Swedish fertility experiment with four P fertilization levels at each site. Total P losses varied between 0.03 and 1.09 kg ha(-1) yr(-1), but no general correlation could be found between P concentrations and soil test P (Olsen P and phosphorus content in ammonium lactate extract [P-AL]) or P sorption indices (single-point phosphorus sorption index [PSI] and P sorption saturation) of the topsoil. Instead, water transport mechanism through the soil and subsoil properties seemed to be more important for P leaching than soil test P value in the topsoil. In one soil, where preferential flow was the dominant water transport pathway, water and P bypassed the high sorption capacity of the subsoil, resulting in high losses. On the other hand, P leaching from some soils was low in spite of high P applications due to high P sorption capacity in the subsoil. Therefore, site-specific factors may serve as indicators for P leaching losses, but a single, general indicator for all soil types was not found in this study.
13. Crystalline and Amorphous Phosphorus – Carbon Nanotube Composites as Promising Anodes for Lithium-Ion Batteries
KAUST Repository
Smajic, Jasmin
2016-05-04
Battery research has been going full steam and with that the search for alternative anodes. Among many proposed electrode materials, little attention has been given to phosphorus. Phosphorus boasts the third highest gravimetric charge capacity and the highest volumetric charge capacity of all elements. Because of that, it would be an attractive battery anode material were it not for its poor cyclability with significant capacity loss immediately after the first cycle. This is known to be the consequence of considerable volume changes of phosphorus during charge/discharge cycles. In this work, we propose circumventing this issue by mixing amorphous red phosphorus with carbon nanotubes. By employing a non-destructive sublimation-deposition method, we have synthesized composites where the synergetic effect between phosphorus and carbon nanotubes allow for an improvement in the electrochemical performance of battery anodes. In fact, it has been shown that carbon nanotubes can act as an effective buffer to phosphorus volumetric expansions and contractions during charging and discharging of the half-cells [1]. By modifying the synthesis parameters, we have also been able to change the degree of crystallinity of the phosphorus matrix in the composites. In fact, the less common phase of red phosphorus, named fibrous phosphorus, was obtained, and that explains some of the varying electrochemical performances observed in the composites. Overall, it is found that a higher surface area of amorphous phosphorus allows for a better anode material when using single-walled carbon nanotubes as fillers.
International Nuclear Information System (INIS)
Jandl, J.; Petr, I.
1988-01-01
International Nuclear Information System (INIS)
Blok, K.; Ginkel, G. van; Leun, K. van der; Muller, H.; Oude Elferink, J.; Vesseur, A.
1985-10-01
This booklet dels with the risks of the use of ionizing radiation for people working in a hospital. It is subdivided in three parts. Part 1 treats the properties of ionizing radiation in general. In part 2 the various applications are discussed of ionizing radiation in hospitals. Part 3 indicates how a not completely safe situation may be improved. (H.W.). 14 figs.; 4 tabs
16. Near-threshold electron impact ionization of Ne and Xe
International Nuclear Information System (INIS)
Yates, B R; Khakoo, M A; Keane, K
2009-01-01
Doubly differential cross-sections for the single electron impact ionization of Ne and Xe have been measured at several energies below the second ionization energy. The results indicate that the ionization of Ne is strongly influenced by the polarization of the ionized 2 2 P 3/2,1/2 core, where as this influence is significantly reduced for Xe. Single differential cross-sections are derived from the doubly differential cross-sections and for Xenon these show profiles similar to Helium ('smile'), whereas for Neon they show a dissimilar profile ('frown').
17. Towards a closed phosphorus cycle
NARCIS (Netherlands)
Keyzer, M.A.
2010-01-01
Summary: This paper stresses the need to address upcoming scarcity of phosphorus, a mineral nutrient that is essential for all life on Earth. Agricultural crops obtain phosphorus from the pool in the soil that can be replenished by recycling of organic material, or by application of inorganic
18. Rapid and precise determination of Sr and Nd isotopic ratios in geological samples from the same filament loading by thermal ionization mass spectrometry employing a single-step separation scheme.
Science.gov (United States)
Li, Chao-Feng; Li, Xian-Hua; Li, Qiu-Li; Guo, Jing-Hui; Li, Xiang-Hui; Yang, Yue-Heng
2012-05-21
Thermal ionization mass spectrometry (TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples, but this method is labour intensive, expensive and time-consuming. In this study, a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental cost. Using the single-step cation exchange resin technique, mixed Sr and rare earth elements (REEs) fractions were separated from matrix and evaporated to dryness. Afterwards, mixed Sr+REEs fractions were dissolved and loaded onto the same Re filament using 1 μL of 2 M HCl. Then, Sr and Nd were sequentially measured without venting using TIMS. In contrast to conventional TIMS methods, the merits of this analytical protocol are its cost- and time-saving adaptations. The applicability of our method is evaluated by replicated measurements of (87)Sr/(86)Sr and (143)Nd/(144)Nd for nine international silicate rock reference materials, spanning a wide range of bulk compositions. The typical internal precision in this study is ca. 0.001% (RSE) for (87)Sr/(86)Sr and (143)Nd/(144)Nd; the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method. Copyright © 2012 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Musilek, L.; Seda, J.; Trousil, J.
1992-01-01
The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs
20. Strong suppression of the positronium channel in double ionization of noble gases by positron impact
DEFF Research Database (Denmark)
Bluhme, H.; Knudsen, H.; Merrison, J.P.
1998-01-01
Positron-induced double ionization of helium and neon has been studied at energies from threshold to 900 eV. A remarkable difference between the near-threshold behavior of the single and double ionization cross sections is found: Single ionization is dominated by positronium (Ps) formation, while...
1. Mechanistic studies of ionizing radiation and oxidative mutagenesis: Genetic effects of a single 8-hydroxyguanine (7-hydro-8-oxoguanine) residue inserted at a unique site in a viral genome
Energy Technology Data Exchange (ETDEWEB)
Wood, M.L.; Essigmann, J.M. (Massachusetts Institute of Technology, Cambridge (USA)); Dizdaroglu, M.; Gajewski, E. (National Institute of Standards and Technology, Gaithersburg, MD (USA))
1990-07-31
T4 RNA ligase was used to construct a deoxypentanucleotide containing a single 8-hydroxyguanine (7-hydro-8-oxoguanine; G{sup 8-OH}) residue, which is one of the putatively mutagenic DNA adducts produced by oxidants and ionizing radiation. The pentamer d(GCTAG{sup 8-OH})p was prepared by the ligation of a chemically synthesized acceptor molecule, d(GCTA), to an adducted donor, 8-hydroxy-2{prime}-deoxyguanosine 5{prime},3{prime}-bisphosphate. Following 3{prime}-dephosphorylation, the pentamer was characterized by UV spectroscopy, by high-pressure liquid chromatography, and by gas chromatography-mass spectrometry of the nucleosides released by enzymatic hydrolysis. Both d(GCTAG{sup 8-OH}) and an unmodified control were 5{prime}-phosphorylated by using ({gamma}-{sup 32}P)ATP and incorporated covalently by DNA ligase into a five-base gap at a unique NheI restriction site in the otherwise duplex genome of an M13mp19 derivative. The adduct was part of a nonsense codon in a unique restriction site in order to facilitate the identification and selection of mutants generated by the replication of the modified genome in Escherichia coli. Both control and adducted pentamers ligated into the genome at 50% of the maximum theoretical efficiency, and nearly all of the site-specifically adducted products possessed pentanucleotides that were covalently linked at both 5{prime} and 3{prime} termini. Transformation of E. coli strain DL7 with the uniquely modified single-stranded genome resulted in {approximately}0.5-1.0% of the progeny phase showing the G {yields} T transversion mutation at the original position of G{sup 8-OH}. The vector containing G{sup 8-OH} also transformed 50-90% as efficiently as the unmodified control, indicating that the adduct can be both weakly cytotoxic and mutagenic to the phase genome.
2. Virtual phosphorus ore requirement of Japanese economy.
Science.gov (United States)
Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya
2011-08-01
Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement. Copyright © 2011 Elsevier Ltd. All rights reserved.
3. Improvements in ionization chambers
International Nuclear Information System (INIS)
Whetten, N.R.; Zubal, C.
1980-01-01
A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)
4. The renaissance of black phosphorus.
Science.gov (United States)
Ling, Xi; Wang, Han; Huang, Shengxi; Xia, Fengnian; Dresselhaus, Mildred S
2015-04-14
One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from condensed matter physicists, chemists, semiconductor device engineers, and material scientists. Similar to graphite and transition metal dichalcogenides (TMDs), black P has a layered structure but with a unique puckered single-layer geometry. Because the direct electronic band gap of thin film black P can be varied from 0.3 eV to around 2 eV, depending on its film thickness, and because of its high carrier mobility and anisotropic in-plane properties, black P is promising for novel applications in nanoelectronics and nanophotonics different from graphene and TMDs. Black P as a nanomaterial has already attracted much attention from researchers within the past year. Here, we offer our opinions on this emerging material with the goal of motivating and inspiring fellow researchers in the 2D materials community and the broad readership of PNAS to discuss and contribute to this exciting new field. We also give our perspectives on future 2D and thin film black P research directions, aiming to assist researchers coming from a variety of disciplines who are desirous of working in this exciting research field.
5. Recycling phosphorus from wastewater
DEFF Research Database (Denmark)
Lemming, Camilla Kjærulff
Phosphorus (P) is an essential plant nutrient and a non-renewable resource of which the future supply to agriculture is challenged by limited and geopolitical unevenly distributed mineral P reserves. Recycling of P from waste is an important mean to minimise the dependence on the limited mineral P...... recycling options. The work of this PhD focused on the plant P availability of sewage sludge, a P-rich residue from wastewater treatment which is commonly applied to agricultural soil in Denmark. The overall objective of the PhD work was to evaluate the plant availability of P in sewage sludge and other...... wastewater-derived products, and to relate this to the availability from other P-containing waste products and mineral P fertiliser. This included aspects of development over time and soil accumulation, as well as effects of soil pH and the spatial distribution in soil. The P sources applied in this PhD work...
6. Introduction to ionizing radiation physics
International Nuclear Information System (INIS)
Musilek, L.
1979-01-01
Basic properties are described of the atom, atomic nucleus and of ionizing radiation particles; nuclear reactions, ionizing radiation sources and ionizing radiation interaction with matter are explained. (J.P.)
7. Electron impact single ionization of copper
Holland Publishing Company, Ams- terdam, 1969) vol. I, p. 353. [16] G Catlow and M R C McDowell, Proc. Phys. Soc. 92, 875 (1967). [17] E Clementi and C Roetti, At. Data Nucl. Data Tables 14, 217 (1974). [18] D C Griffin and M S Pindzola, ...
8. Electron impact single ionization of copper
Author Affiliations. L K Jha1 O P Roy2 B N Roy3. Department of Physics, L.N.T. College, Muzaffarpur 842 002, India; Department of Physics, M.S.K.B. College, Muzaffarpur 842 002, India; Professor's Colony, Aghoria Bazar, Muzaffarpur 842 002, India ...
9. Charge exchange between singly ionized helium ions
International Nuclear Information System (INIS)
Choi, B.H.; Poe, R.T.; Tang, K.T.
1978-01-01
The plane-wave Born approximation was used to evaluate the charge transfer cross sections for the reaction He + + He + → He ++ + He. The charge transfer cross section is graphed as a function of incident energy and compared with experimental measurements
10. Magnesium, calcium and phosphorus in the intensive care unit: Do ...
African Journals Online (AJOL)
Magnesium, calcium and phosphorus are important electrolytes involved in the regulation of homeostasis. However the utility in monitoring them in critically ill patients is still unclear. We therefore undertook a prospective, non-interventional, single center study in the intensive care unit of a tertiary care hospital in ...
11. Biological Effects of Ionizing Radiation
Science.gov (United States)
Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.
1952-04-07
This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.
12. Physically sound parameterization of incomplete ionization in aluminum-doped silicon
Directory of Open Access Journals (Sweden)
Heiko Steinkemper
2016-12-01
Full Text Available Incomplete ionization is an important issue when modeling silicon devices featuring aluminum-doped p+ (Al-p+ regions. Aluminum has a rather deep state in the band gap compared to boron or phosphorus, causing strong incomplete ionization. In this paper, we considerably improve our recent parameterization [Steinkemper et al., J. Appl. Phys. 117, 074504 (2015]. On the one hand, we found a fundamental criterion to further reduce the number of free parameters in our fitting procedure. And on the other hand, we address a mistake in the original publication of the incomplete ionization formalism in Altermatt et al., J. Appl. Phys. 100, 113715 (2006.
13. Kelvin spray ionization.
Science.gov (United States)
Özdemir, Abdil; Lin, Jung-Lee; Gillig, Kent J; Chen, Chung-Hsuan
2013-11-21
A novel self-powered dual spray ionization source has been developed for applications in mass spectrometry. This new source does not use any power supply and produces both positive and negative ions simultaneously. The idea behind this ionization source comes from the Kelvin water dropper. The source employs one or two syringes, two pneumatic sprays operated over a range of flow rates (0.15-15 μL min(-1)) and gas pressures (0-150 psi), and two double layered metal screens for ion formation. A variable electrostatic potential from 0 to 4 kV can be produced depending on solvent and gas flow rates that allow gentle ionization of compounds. There are several parameters that affect the performance during ionization of molecules including the flow rate of solvent, gas pressure, solvent acidity, position of spray and metal screens with respect to each other and distance between metal screens and the counter electrode. This ionization method has been successfully applied to solutions of peptides, proteins and non-covalent complexes. In comparison with ESI, the charge number of the most populated state is lower than that from ESI. It indicates that this is a softer ionization technique and it produces more protein ions with folded structures. The unique features of Kelvin spray ionization (KeSI) are that the method is self-powered and ionization occurs at very low potentials by providing very low internal energy to the ions. This advantage can be used for the ionization of very fragile molecules and investigation of non-covalent interactions.
14. Phosphorus chemistry in everyday living
National Research Council Canada - National Science Library
Toy, Arthur D. F
1976-01-01
The author has drawn on his 35 years of experience as a research scientist in phosphorus chemistry to produce a book that is not only readable to the non-chemist but sophisticated enough to interest...
15. Total Phosphorus in Surface Water
Data.gov (United States)
U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...
16. Dietary phosphorus and kidney disease.
Science.gov (United States)
Uribarri, Jaime
2013-10-01
High serum phosphate is linked to poor health outcome and mortality in chronic kidney disease (CKD) patients before or after the initiation of dialysis. Therefore, maintenance of normal serum phosphate levels is a major concern in the clinical care of this population with dietary phosphorus restriction and/or use of oral phosphate binders considered to be the best corrective care. This review discusses (1) evidence for an association between serum phosphate levels and bone and cardiovascular disease (CVD) in CKD patients as well as progression of kidney disease itself; (2) the relationship between serum phosphate and dietary phosphorus intake; and (3) implications from these data for future research. Increasing our understanding of the relationship between altered phosphorus metabolism and disease in CKD patients may clarify the potential role of excess dietary phosphorus as a risk factor for disease in the general population. © 2013 New York Academy of Sciences.
17. Missisquoi Bay Phosphorus Model Addendum
Science.gov (United States)
This technical memorandum provides results of an extended load reduction simulation. The memorandum serves as an addendum to the main Missisquoi Bay Phosphorus Mass Balance Model report prepared for the Lake Champlain Basin Program by LimnoTech in 2012
18. phosphorus retention data and metadata
Science.gov (United States)
phosphorus retention in wetlands data and metadataThis dataset is associated with the following publication:Lane , C., and B. Autrey. Phosphorus retention of forested and emergent marsh depressional wetlands in differing land uses in Florida, USA. Wetlands Ecology and Management. Springer Science and Business Media B.V;Formerly Kluwer Academic Publishers B.V., GERMANY, 24(1): 45-60, (2016).
19. Quantum confinement in black phosphorus-based nanostructures
Science.gov (United States)
Cupo, Andrew; Meunier, Vincent
2017-07-01
The modification of an idealized infinite bulk system by dimensional reduction or structural distortion results in quantum confinement effects (QCEs). For example, dimensional reduction of a black phosphorus structure leads to the realization of few-layer systems, creation of edges and surfaces, nanoribbons, quantum dots, and antidot lattices while structural distortion involves simple bending (including nanotubes) and rippling. Black phosphorus (‘phosphorene’ in the single-layer limit) has been of recent interest due to its relatively large charge carrier mobility and moderate semiconducting band gap, which remains direct irrespective of the number of layers. In this review the state-of-the-art properties of black phosphorus in its dimensionally reduced and structurally distorted forms are discussed, with emphasis on how quantum confinement impacts the material’s properties.
20. Miniature ionization chamber
International Nuclear Information System (INIS)
Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.
1976-01-01
A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber
1. Electron Doping of Ultrathin Black Phosphorus with Cu Adatoms.
Science.gov (United States)
Koenig, Steven P; Doganov, Rostislav A; Seixas, Leandro; Carvalho, Alexandra; Tan, Jun You; Watanabe, Kenji; Taniguchi, Takashi; Yakovlev, Nikolai; Castro Neto, Antonio H; Özyilmaz, Barbaros
2016-04-13
Few-layer black phosphorus is a monatomic two-dimensional crystal with a direct band gap that has high carrier mobility for both holes and electrons. Similarly to other layered atomic crystals, like graphene or layered transition metal dichalcogenides, the transport behavior of few-layer black phosphorus is sensitive to surface impurities, adsorbates, and adatoms. Here we study the effect of Cu adatoms onto few-layer black phosphorus by characterizing few-layer black phosphorus field effect devices and by performing first-principles calculations. We find that the addition of Cu adatoms can be used to controllably n-dope few layer black phosphorus, thereby lowering the threshold voltage for n-type conduction without degrading the transport properties. We demonstrate a scalable 2D material-based complementary inverter which utilizes a boron nitride gate dielectric, a graphite gate, and a single bP crystal for both the p- and n-channels. The inverter operates at matched input and output voltages, exhibits a gain of 46, and does not require different contact metals or local electrostatic gating.
2. Comparison of three persulfate digestion methods for total phosphorus analysis and estimation of suspended sediments
International Nuclear Information System (INIS)
Dayton, Elizabeth Ann; Whitacre, Shane; Holloman, Christopher
2017-01-01
the number of procedures that can be run on a single water sample. - Highlights: • The Acid Persulfate method was most effective, with an average total phosphorus percent recovery of 96.6%. • The second most effective method was the USGS with an average total phosphorus recovery of 76.1%. • The Alkaline Persulfate method performed poorly with an average 24.5% total phosphorus recovery. • Application of Alkaline Persulfate digestion to edge of field monitoring may drastically underestimated runoff total phosphorus. • The Acid Persulfate method combined with analysis of Al and Fe provides a robust prediction of total SS.
3. Directed Field Ionization
Science.gov (United States)
Gregoric, Vincent C.; Kang, Xinyue; Liu, Zhimin Cheryl; Rowley, Zoe A.; Carroll, Thomas J.; Noel, Michael W.
2017-04-01
Selective field ionization is an important experimental technique used to study the state distribution of Rydberg atoms. This is achieved by applying a steadily increasing electric field, which successively ionizes more tightly bound states. An atom prepared in an energy eigenstate encounters many avoided Stark level crossings on the way to ionization. As it traverses these avoided crossings, its amplitude is split among multiple different states, spreading out the time resolved electron ionization signal. By perturbing the electric field ramp, we can change how the atoms traverse the avoided crossings, and thus alter the shape of the ionization signal. We have used a genetic algorithm to evolve these perturbations in real time in order to arrive at a target ionization signal shape. This process is robust to large fluctuations in experimental conditions. This work was supported by the National Science Foundation under Grants No. 1607335 and No. 1607377 and used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant Number OCI-1053575.
4. Dietary Phosphorus Intake and the Kidney.
Science.gov (United States)
Chang, Alex R; Anderson, Cheryl
2017-08-21
Although phosphorus is an essential nutrient required for multiple physiological functions, recent research raises concerns that high phosphorus intake could have detrimental effects on health. Phosphorus is abundant in the food supply of developed countries, occurring naturally in protein-rich foods and as an additive in processed foods. High phosphorus intake can cause vascular and renal calcification, renal tubular injury, and premature death in multiple animal models. Small studies in human suggest that high phosphorus intake may result in positive phosphorus balance and correlate with renal calcification and albuminuria. Although serum phosphorus is strongly associated with cardiovascular disease, progression of kidney disease, and death, limited data exist linking high phosphorus intake directly to adverse clinical outcomes. Further prospective studies are needed to determine whether phosphorus intake is a modifiable risk factor for kidney disease.
5. Resonantly enhanced inner-orbital ionization in molecular iodine
Science.gov (United States)
Smith, Dale L.; Gibson, George N.
2018-02-01
We present a wavelength study of the strong-field single-electron ionization of molecular iodine near its one-photon B -state resonance at 530 nm. We have previously identified two ionization channels [Phys. Rev. A 95, 013410 (2017), 10.1103/PhysRevA.95.013410]: ionization of the high-lying molecular orbitals and ionization of the deep orbitals in I2. We find a resonant enhancement of both channels, although the peak enhancement occurs at different wavelengths for the different channels. Moreover, the branching ratio of the ionization of the deep orbitals shows a dispersion-like function, with the branching ratio of the deep orbitals reaching over 98% at 519 nm. Finally, the branching ratio of double ionization into an excited state of I22+ as a function of wavelength closely matches the branching ratio of the single ionization of deep orbitals, implying that excitation of molecular ions generally comes about through inner orbital ionization. These findings are inconsistent with current molecular ionization theory.
6. Studies of the utilization of phosphorus and nitrogen fertilizers by 32P and 15N isotopes
International Nuclear Information System (INIS)
Dombovari, Janos; Kiss, A.S.
1983-01-01
The utilization of phosphorus and nitrogen fertilizers in crop enhancement was studied with different plants and soils, using 15 N nad 32 P labelling. 15 N was determined by mass spectrometry, 32 P by radiometry. For nitrogen fertilizers better results were achieved by sequential small doses than by single higher doses. The utilization of phosphorus fertilizer strongly depends, in addition to the plant species, on the quality of the soil, especially on its Ca and N contents. Low and high soil liming increased and decreased the utilization of phosphorus, respectively, while nitrogen fertilizers increased it in each case. Measurement of the isotopically exchangable phosphorus content of soils represents a new technique for the determination of the phosphorus uptake. (A.L.)
7. [Effects of phosphorus sources on phosphorus fractions in rhizosphere soil of wild barley genotypes with high phosphorus utilization efficiency].
Science.gov (United States)
Cai, Qiu-Yan; Zhang, Xi-Zhou; Li, Ting-Xuan; Chen, Guang-Deng
2014-11-01
High P-efficiency (IS-22-30, IS-22-25) and low P-efficiency (IS-07-07) wild barley cultivars were chosen to evaluate characteristics of phosphorus uptake and utilization, and properties of phosphorus fractions in rhizosphere and non-rhizosphere in a pot experiment with 0 (CK) and 30 mg P · kg(-1) supplied as only Pi (KH2PO4), only Po (phytate) or Pi + Po (KH2PO4+ phytate). The results showed that dry matter and phosphorus accumulation of wild barley in the different treatments was ranked as Pi > Pi + Po > Po > CK. In addition, dry matter yield and phosphorus uptake of wild barley with high P-efficiency exhibited significantly greater than that with low P-efficiency. The concentration of soil available phosphorus was significantly different after application of different phosphorus sources, which was presented as Pi > Pi + Po > Po. The concentration of soil available phosphorus in high P-efficiency wild barley was significantly higher than that of low P-efficiency in the rhizosphere soil. There was a deficit in rhizosphere available phosphorus of high P-efficiency wild barley, especially in Pi and Pi+Po treatments. The inorganic phosphorus fractions increased with the increasing Pi treatment, and the concentrations of inorganic phosphorus fractions in soil were sorted as follows: Ca10-P > O-P > Fe-P > Al-P > Ca2-P > Ca8-P. The contents of Ca2-P and Ca8-P for high P-efficiency wild barley showed deficits in rhizosphere soil under each phosphorus source treatment. In addition, enrichment of Al-P and Fe-P was observed in Pi treatment in rhizosphere soil. The concentrations of organic phosphorus fractions in soil were sorted as follows: moderate labile organic phosphorus > moderate resistant, resistant organic phosphorus > labile organic phosphorus. The labile and moderate labile organic phosphorus enriched in rhizosphere soil and the greatest enrichment appeared in Pi treatment. Furthermore, the concentrations of moderate resistant organic phosphorus and resistant
8. Electron Impact Ionization of C60
International Nuclear Information System (INIS)
Duenser, B.; Lezius, M.; Scheier, P.; Deutsch, H.; Maerk, T.D.
1995-01-01
Absolute partial and total cross sections for the electron impact ionization of C 60 have been measured using a novel approach for the absolute calibration. The results obtained reveal not only an anomalous large parent ion cross section (as compared to the other ionization channels), but also anomalies for the production of multiply charged parent and fragment ions. This special behavior has its origin in the specific electronic and geometric structure of C 60 . Semiclassical calculations for singly charged ions support the measured data
9. Dynamically Optimal Phosphorus Management and Agricultural Water Protection
OpenAIRE
Iho, Antti; Laukkanen, Marita
2009-01-01
This paper puts forward a model of the role of phosphorus in crop production, soil phosphorus dynamics and phosphorus loading that integrates the salient economic and ecological features of agricultural phosphorus management. The model accounts for the links between phosphorus fertilization, crop yield, accumulation of soil phosphorus reserves, and phosphorus loading. It can be used to guide precision phosphorus management and erosion control as means to mitigate agricultural loading. Using a...
10. Low Phosphorus Diet: Best for Kidney Disease?
Science.gov (United States)
... limit foods highest in phosphorus, including: Fast food, convenience foods and processed foods, which may be full of ... food labels. Be aware that fast foods and convenience foods have potentially large amounts of phosphorus. Seek professional ...
11. Electric Conductivity of Phosphorus Nanowires
International Nuclear Information System (INIS)
Jing-Xiang, Zhang; Hui, Li; Xue-Qing, Zhang; Kim-Meow, Liew
2009-01-01
We present the structures and electrical transport properties of nanowires made from different strands of phosphorus chains encapsulated in carbon nanotubes. Optimized by density function theory, our results indicate that the conductance spectra reveal an oscillation dependence on the size of wires. It can be seen from the density of states and current-voltage curves that the structure of nanowires affects their properties greatly. Among them, the DNA-like double-helical phosphorus nanowire exhibits the distinct characteristic of an approximately linear I – V relationship and has a higher conductance than others. The transport properties of phosphorus nanowires are highly correlated with their microstructures. (condensed matter: structure, mechanical and thermal properties)
12. Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil
OpenAIRE
H. SOINNE; K. SAARIJÄRVI; M. KARPPINEN
2008-01-01
The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P) chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc) and water extractable total P (TPw), and mo...
13. Phosphorus Flamethrower: A Demonstration Using Red and White Allotropes of Phosphorus
Science.gov (United States)
Golden, Melissa L.; Person, Eric C.; Bejar, Miriam; Golden, Donnie R.; Powell, Jonathan M.
2010-01-01
A demonstration was created to display the unique behavior of a familiar element, phosphorus, and to make chemistry more accessible to the introductory student. The common allotropes of phosphorus and their reactivity are discussed. In this demonstration, the white allotrope of phosphorus is synthesized from the red phosphorus obtained from a…
14. The critical ionization velocity
International Nuclear Information System (INIS)
1980-06-01
The critical ionization velocity effect was first proposed in the context of space plasmas. This effect occurs for a neutral gas moving through a magnetized plasma and leads to rapid ionization and braking of the relative motion when a marginal velocity, 'the critical velocity', is exceeded. Laboratory experiments have clearly established the significance of the critical velocity and have provided evidence for an underlying mechanism which relies on the combined action of electron impact ionization and a collective plasma interaction heating electrons. There is experimental support for such a mechanism based on the heating of electrons by the modified two-stream instability as part of a feedback process. Several applications to space plasmas have been proposed and the possibility of space experiments has been discussed. (author)
15. Surface ionization theory
International Nuclear Information System (INIS)
Bonnal, J.-F.; Pelissier, Andre
1974-01-01
After a brief theoretical review, the relationship existing between the ionization rate in the vicinity of a metallic plate in thermodynamic equilibrium with a cesium plasma and the density of electron current issued from the same plate is presented. The evolution of this density of current is represented by the Langmuir S-curves. It is shown that knowledge of the S-curves leads to that of the critical temperatures and of the ionization rates when the generated ions are extracted by an electric field. The influence of the principal parameters (the nature and temperature of the plate and the cesium flow supplying it) is analyzed using the Rasor theory. The theoretical results obtained using a model of the flat plate represent fairly closely the operations observed experimentally on porous tungstem ionizers [fr
16. The ionizing treatment of food
International Nuclear Information System (INIS)
1998-01-01
This book of proceedings contains the talks given by the members of the Society of chemical experts of France (SECF) and by various specialists of the ionizing treatment during the scientific days of September 25-26, 1997. The aim of this meeting was to reconsider the effects of ionization from a scientific point of view and apart from the polemics generated by this domain. The following topics were discussed successively: source and characterization of a ionizing treatment, biological effects of ionization on food and the expected consequences, the ionizing treatment and the reduction of the vitamin C content of fruits and vegetables, is it safe to eat irradiated food?, the organoleptic modifications of food after ionization, quality assurance of dosimetry measurements in an industrial installation of food ionization, the French and European regulations in food ionization, the detection of irradiated foodstuffs, processed food and complex lipid matrices, sterilization of dishes for immuno-depressed patients using ionization. (J.S.)
17. Contact ionization ion source
International Nuclear Information System (INIS)
Hashmi, N.; Van Der Houven Van Oordt, A.J.
1975-01-01
An ion source in which an apertured or foraminous electrode having a multiplicity of openings is spaced from one or more active surfaces of an ionisation electrode, the active surfaces comprising a material capable of ionising by contact ionization a substance to be ionized supplied during operation to the active surface or surfaces comprises means for producing during operation a magnetic field which enables a stable plasma to be formed in the space between the active surface or surfaces and the apertured electrode, the field strength of the magnetic field being preferably in the range between 2 and 8 kilogauss. (U.S.)
International Nuclear Information System (INIS)
Rida Tajau; Kamarudin Hashim; Jamaliah Sharif; Ratnam, C.T.; Keong, C.C.
2017-01-01
This book completely brief on the basic concept and theory of ionizing radiation in polymers material processing. Besides of that the basic concept of polymerization addition, cross-linking and radiation degradation also highlighted in this informative book. All of the information is from scientific writing based on comprehensive scientific research in polymerization industry which using the radiation ionizing. It is very useful to other researcher whose study in Nuclear Sciencea and Science of Chemical and Material to use this book as a guideline for them in future scientific esearch.
International Nuclear Information System (INIS)
deGaston, A.N.
1979-01-01
A normally nonconducting liquid such as liquid hydrocarbon is encased between a pair of electrodes in an enclosure so that when the liquid is subjected to ionizing radiation, the ion pairs so created measurably increase the conductivity of the fluid. The reduced impedance between the electrodes is detectable with a sensitive ohm-meter and indicates the amount of ionizing radiation. The enclosure, the electrodes and the fluid can be constructed of materials that make the response of the detector suitable for calibrating a large range of radiation energy levels. The detector is especially useful in medical applications where tissue equivalent X ray detectors are desired
20. Biological effects of ionizing radiation
International Nuclear Information System (INIS)
Gisone, Pablo; Perez, Maria R.
2001-01-01
1. NMR Metabolomics in Ionizing Radiation
Energy Technology Data Exchange (ETDEWEB)
Hu, Jian Z.; Xiao, Xiongjie; Hu, Mary Y.
2016-09-08
Ionizing radiation is an invisible threat that cannot be seen, touched or smelled and exist either as particles or waves. Particle radiation can take the form of alpha, beta or neutrons, as well as high energy space particle radiation such as high energy iron, carbon and proton radiation, etc. (1) Non-particle radiation includes gamma- and x-rays. Publically, there is a growing concern about the adverse health effects due to ionizing radiation mainly because of the following facts. (a) The X-ray diagnostic images are taken routinely on patients. Even though the overall dosage from a single X-ray image such as a chest X-ray scan or a CT scan, also called X-ray computed tomography (X-ray CT), is low, repeated usage can cause serious health consequences, in particular with the possibility of developing cancer (2, 3). (b) Human space exploration has gone beyond moon and is planning to send human to the orbit of Mars by the mid-2030s. And a landing on Mars will follow.
2. Estimating phosphorus intake by grazing sheep
African Journals Online (AJOL)
Estimating phosphorus intake in grazing sheep is ditficult since hand-picked ... Thus to establish the intake of phosphorus, a method other than forage .... between the mean (tSD) levels in the ribs of the sheep and the. S.-Afr. Tydskr. Veek. 19g3, l3(3) of phosphorus and feed they consumed. Determination. Specimen".
3. Phosphorus and Calcium Metabolism in Postmenopausal Women with Diabetes Mellitus: Effects of the Type and Duration of the Disease, Time of Menopause and Body Mass
Directory of Open Access Journals (Sweden)
M.L. Kyryliuk
2016-02-01
Full Text Available The article deals with the impact of diabetes mellitus (DM on the phosphorus and calcium metabolism in postmenopausal women, depending on the type and duration of the disease, duration of menopause, body mass and type of hypoglycemic therapy. The state of phosphorus and calcium metabolism in 86 women with type 1 DM (13 patients and type 2 DM (73 patients was studied. In all patients, the concentration of calcium and phosphorus in the blood was within normal limits. It was found that the concentration of ionized calcium, total calcium and inorganic phosphorus in the blood can not be the main criterion for the state of bone mineral density in postmenopausal women with DM. Sulfonylureas and insulin in combination with biguanides have no effect on the status of phosphorus and calcium metabolism in postmenopausal women with type 2 DM.
International Nuclear Information System (INIS)
This booklet is concerned with radiation safety of radiologist and other hospital personnel. Part 1 deals with properties of radiation in general (especially of ionizing radiation). In part 2, different applications of radiation in hospitals are discussed. Part 3 indicates what to do to make improvements to not totally safe situations in hospitals. (Auth./G.J.P.)
5. Ionization beam scanner
CERN Multimedia
CERN PhotoLab
1973-01-01
Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.
6. Detection of ionized foods
International Nuclear Information System (INIS)
Beerens, H.
1986-01-01
Irradiated foods and feed might be identified with two kinds of tests: 1. biochemical: detection of specific products are not yet available 2. microbiological: when a microbial species dissapears from a sample of food i.e. it is not detectable after enrichment (for instance Coliforms in hamburgers) it is likely that the sample has been ionized [fr
7. Ionization chamber smoke detectors
International Nuclear Information System (INIS)
1988-03-01
One kind of smoke detector, the ionization-type, is regulated by the Atomic Energy Control Board (AECB) because it uses a radioactive substance in its mechanism. Radioactivity and radiation are natural phenomena, but they are not very familiar to the average householder. This has led to a number of questions being asked of the AECB. These questions and AECB responses are outlined
8. Ionization loss in BGO
International Nuclear Information System (INIS)
Bakken, J.A.; Denes, P.; Piroue, P.A.; Stickland, D.P.; Sumner, R.L.; Taylor, C.; Barone, L.; Borgia, B.; Diemoz, M.; Dionisi, C.; Falciano, S.; Ferroni, F.; Gratta, G.; Longo, E.; Luminari, L.; Morganti, S.; Valente, E.; Blaising, J.J.; Boutigny, D.; Coignet, G.; Karyotakis, Y.; Sauvage, G.; Schneegans, M.; Vivargent, M.; Extermann, P.; Morand, G.; Ossmann, J.; Ruckstuhl, W.; Schaad, T.P.; Lecoq, P.; Walk, W.; Li, P.J.; Micke, M.; Micke, U.; Schmitz, D.
1988-01-01
We report on a precise measurement of the energy loss through ionization by pions in bismuth germanate performed at several values of the incident particles momentum with a prototype of the L3 electromagnetic calorimeter. The experimental results are in good agreement with theoretical predictions showing the relativistic rise modified by density effect. (orig.)
9. Greening the global phosphorus cycle
NARCIS (Netherlands)
Withers, Paul J.A.; Elser, James J.; Hilton, Julian; Ohtake, Hisao; Schipper, Willem J.; Dijk, Van Kimo C.
2015-01-01
The sustainability of global phosphorus (P) use is emerging as a major societal goal to secure future food, energy, and water security for a growing population. Phosphate rock (PR) is a critical raw material whose inefficiency of use is leading to widespread eutrophication and uncertainties about
10. Phosphorus requirement in laying hens
NARCIS (Netherlands)
Lambert, W.; Krimpen, van M.M.; Star, L.
2014-01-01
It was hypothesized that P supply by feed in alternative housing systems can be lowered without negative effects on bone quality and production performance. Therefore, the objectives of the current study were 1) to update the retainable phosphorus (rP) needs of two modern laying hen breeds from 36
11. SEQUENTIAL ELECTRODIALYTIC EXTRACTION OF PHOSPHORUS COMPOUNDS
DEFF Research Database (Denmark)
2017-01-01
The present invention relates to an apparatus for electrodialytic extraction of phosphorus from a particulate material in suspension and to a method for electrodialytic phosphorus recovery, which uses the apparatus. The method may be applied for wastewater treatment, and/or treatment of particulate...... material rich in phosphorus. The present invention provides an apparatus for electrodialytic extraction of phosphorus from a particulate material comprising acidic and/or alkaline soluble phosphorus compounds, in suspension, comprising: • a first electrodialytic cell comprising a first anolyte compartment...
12. Few-layer black phosphorus nanoparticles.
Science.gov (United States)
Sofer, Zdenek; Bouša, Daniel; Luxa, Jan; Mazanek, Vlastimil; Pumera, Martin
2016-01-28
Herein, black phosphorus quantum dots and nanoparticles of a few layer thickness were prepared and characterized using STEM, AFM, dynamic light scattering, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and photoluminescence. Impact electrochemistry of the induvidual black phosphorus nanoparticles allows their size determination. The centrifugation of colloidal black phosphorus nanoparticles allowed separation of quantum dots with sizes up to 15 nm. These black phosphorus nanoparticles exhibit a large band gap and are expected to find a wide range of applications from semiconductors to biomolecule tags. The use of black phosphorus nanoparticles for vapour sensing was successfully demonstrated.
13. Numerical simulations of single and double ionization of H{sub 2} in short intense laser pulses; Numerische Simulation zur Einfach- und Doppelionisation von H{sub 2} in kurzen intensiven Laserpulsen
Energy Technology Data Exchange (ETDEWEB)
Baier, Silvio
2008-07-01
Rescattering is the dominant process leading to double ionization in atoms and molecules interacting with linearly polarized laser pulses with wavelengths around 800 nm and in an intensity regime of 10{sup 14} to 10{sup 15} W/cm{sup 2}. Using numerical integrations of the two-electron Schroedinger equation of the Hydrogen molecule in appropriate reduced dimensions two mechanisms, namely correlated emission of the electrons and excitation followed by field ionization after rescattering, could be identified and characterized. With the help of a planar model in reduced dimensions these mechanisms were quantitatively compared by their dependence on the molecular alignment with respect to the polarization axis. Two additional mechanisms, which are also related to rescattering, could be identified as well. (orig.)
14. Optical Imaging of Ionizing Radiation from Clinical Sources.
Science.gov (United States)
Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan
2016-11-01
15. Estimate of dietary phosphorus intake using 24-h urine collection
OpenAIRE
Morimoto, Yuuka; Sakuma, Masae; Ohta, Hiroyuki; Suzuki, Akitsu; Matsushita, Asami; Umeda, Minako; Ishikawa, Makoto; Taketani, Yutaka; Takeda, Eiji; Arai, Hidekazu
2014-01-01
Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two he...
16. The application of soil amendments benefits to the reduction of phosphorus depletion and the growth of cabbage and corn.
Science.gov (United States)
Liu, Wei; Ji, Hongli; Kerr, Philip; Wu, Yonghong; Fang, Yanming
2015-11-01
The loss of phosphorus from agricultural intensive areas can cause ecological problems such as eutrophication in downstream surface waters. Therefore, the purpose of this study is to control the phosphorus loss using environmentally benign soil amendments, viz, ferrous sulfate (FES), aluminum sulfate (ALS), and polyacrylamide (PAM). The phosphorus concentration changes in soil and leaching solution, the morphological index of plant (including stem and root), and root activity and quality (represented by chlorophyll and soluble sugar) at different growth stages of cabbage (Brassica oleracea L. var. capitata L.) were monitored in a pilot experiment. Phosphorus contents in soil and runoff were also investigated in field experiments cultivated with corn (Zea mays L.). The results show that the application of these amendments improved the phosphorus uptake by cabbage and corn, resulting in the enhanced morphologies of root and stem as well as the root activity at the early and middle stages of cabbage growth. The soil total phosphorus and available phosphorus in soils treated with FES, ALS, and PAM declined, resulting in lower concentrations of phosphorus in the leachate and the soil runoff. During the use of the soil amendments, the cabbage quality measures, determined as chlorophyll and soluble sugar in leaves, were not significantly different from those in the control. It is suggested that the application of these soil amendments is safe for cabbage production under single season cropping conditions, and the use of these three amendments is a promising measure to reduce phosphorus loss in intensive agricultural areas.
International Nuclear Information System (INIS)
Bourguignon, M.; Masse, R.; Slama, R.; Spira, A.; Timarche, M.; Laurier, D.; Billon, S.; Rogel, A.; Telle Lamberton, M.; Catelinois, O.; Thierry, I.; Grosche, B.; Ron, E.; Vathaire, F. de; Cherie Challine, L.; Donadieu, J.; Pirard, Ph.; Bloch, J.; Setbon, M.
2004-01-01
The ionizing radiations have effects on living being. The determinist effects appear since a threshold of absorbed dose of radiation is reached. In return, the stochastic effects of ionizing radiations are these ones whom apparition cannot be described except in terms of probabilities. They are in one hand, cancers and leukemia, on the other hand, lesions of the genome potentially transmissible to the descendants. That is why epidemiology, defined by specialists as the science that studies the frequency and distribution of illness in time and space, the contribution of factors that determine this frequency and this distribution among human populations. This issue gathers and synthesizes the knowledge and examines the difficulties of methodologies. It allows to give its true place to epidemiology. (N.C.)
International Nuclear Information System (INIS)
Fajardo, L.F.
1986-01-01
Among the well accepted causes of neoplasia, ionizing radiation is quite prominent. Its oncogenic role was suspected by a few pioneers in the field of radiation biology, and some evidence for its oncogenicity has been available for almost 80 years. Since then unquestionable and abundant proof, statistical and experimental, has linked radiation with multiple tumors in mammals. Other forms of radiation (e.g., ultraviolet) are also causally related to neoplasia. This review, however, refers only to the tumors associated with ionizing radiation, either electromagnetic (i.e., gamma and x-rays) or particulate (alpha particles, neutrons, etc.). The field of radiation oncogenesis can be compared to a sea of hypotheses, with a few solid islands of facts. This paper considers the facts (specific radiation-induced neoplasms, risk data, etc.) and then considers some of the hypotheses (possible mechanisms of radiation oncogenesis)
19. Ionization by nuclear transitions
International Nuclear Information System (INIS)
Freedman, M.S.
1975-01-01
A phenomenological description of ionization events is given that applies to both shaking transitions of the composite nucleus-atom system and the process in which the charged particles emitted in a nuclear decay transfer energy by a relatively slow ''direct collision'' final state interaction with atomic electrons. Specific areas covered include shakeoff in internal conversion, shakeoff in electron capture, shakeoff in beta decay, and inner electron ejection in alpha decay. (5 figs., 1 table)
20. Gridded Ionization Chamber
International Nuclear Information System (INIS)
Manero Amoros, F.
1962-01-01
In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs
International Nuclear Information System (INIS)
Plataniotis, Th.N.; Nikolaou, K.I.; Syrgiamiotis, G.V.; Dousi, M.; Panou, Th.; Georgiadis, K.; Bougias, C.
2008-01-01
International Nuclear Information System (INIS)
Fischer, P.G.
1983-01-01
The still growing use of non-ionizing radiation such as ultraviolet radiation laser light, ultrasound and infrasound, has induced growing interest in the effects of these types of radiation on the human organism, and in probable hazards emanating from their application. As there are up to now no generally approved regulations or standards governing the use of non-ionizing radiation and the prevention of damage, it is up to the manufacturers of the relevant equipment to provide for safety in the use of their apparatus. This situation has led to a feeling of incertainty among manufacturers, as to how which kind of damage should be avoided. Practice has shown that there is a demand for guidelines stating limiting values, for measuring techniques clearly indicating safety thresholds, and for safety rules providing for safe handling. The task group 'Non-ionizing radiation' of the Radiation Protection Association started a programme to fulfill this task. Experts interested in this work have been invited to exchange their knowledge and experience in this field, and a collection of loose leaves will soon be published giving information and recommendations. (orig./HP) [de
3. Phosphorus Recovery from Ashes of Sewage Sludge
Energy Technology Data Exchange (ETDEWEB)
Cornel, Peter; Schaum, Peter
2003-07-01
About 90% of the incoming phosphorus load of waste water is eliminated by waste water treatment and transferred into the sewage sludge. Considerable amounts of sewage sludge can not be used agriculturally but are incinerated. Thus the ash from mono sludge incineration plants contains significant amounts of phosphorus (up to 25% P{sub 2}O{sub 5}) and could be used as raw material in fertilizer industry. The ash is hygienically harmless and free of organic substances. The ratio of phosphorus to heavy metals is basically the same as in the sewage sludge. The first step in separating phosphorus from heavy metals is to dissolve phosphorus by extraction. The most promising way seems to be the release of phosphorus with acids or bases. With 1 m sulphuric acid it is possible to release phosphorus completely. By use of acid most of the heavy metals dissolve, too. With caustic soda as solvent, only 30-40% of the phosphorus can be dissolved but the eluate is almost free of heavy metals. The amount of phosphorus which can be released with caustic soda, depends on the applied precipitant (Al or Fe salts) for phosphorus elimination at the waste water treatment. (author)
4. Dietary phosphorus acutely impairs endothelial function.
Science.gov (United States)
Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji
2009-07-01
Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.
5. Phosphorus cycle - possibilities for its rebuilding.
Science.gov (United States)
Gorazda, Katarzyna; Wzorek, Zbigniew; Tarko, Barbara; Nowak, Anna K; Kulczycka, Joanna; Henclik, Anna
2013-01-01
The rebuilding of the phosphorus cycle can be performed with the use of both biotechnology and chemical technology. This paper presents a review of the phosphorus cycle and the different approaches that can be taken to the recovery of phosphorus from phosphate-rich waste. Critical issues in the phosphorus cycle are also discussed. Methods for the recovery of phosphorus form sewage sludge ash are widely explored and divided into two groups: wet extraction methods and thermochemical methods. Laboratory-scale methods are described, as well as proposed industrial technologies, with particular regard to the possibilities for their implementation in Poland. Phosphorus recovery methods from SSA (sewage sludge ash) in our country seems to be promising due to the increasing number of sewage sludge incineration plants, which could easily supply ash to future recovery installations. For the effective recovery of P from sewage sludge ash, it is essential to make the right choice in determining the appropriate method to use with respect to the particular properties of the ash composition available. A patented method of phosphorus recovery by acid extraction methods, developed by Cracow University of Technology, results in an efficiency of 80-96% for phosphorus recovery. 3000 to 4000 tons of phosphorus per year can be recycled and introduced back into the environment, that covers around 7% of the total amount of phosphorus ore imported into Poland between 2008 and 2009.
6. Near-Threshold Ionization of Argon by Positron Impact
Science.gov (United States)
Babij, T. J.; Machacek, J. R.; Murtagh, D. J.; Buckman, S. J.; Sullivan, J. P.
2018-03-01
The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works. In fact, in this work, we see no difference in threshold behavior between the positron and electron cases. Possible reasons for this discrepancy are discussed.
7. Association of dietary phosphorus intake and phosphorus to protein ratio with mortality in hemodialysis patients.
Science.gov (United States)
Noori, Nazanin; Kalantar-Zadeh, Kamyar; Kovesdy, Csaba P; Bross, Rachelle; Benner, Debbie; Kopple, Joel D
2010-04-01
Epidemiologic studies show an association between higher predialysis serum phosphorus and increased death risk in maintenance hemodialysis (MHD) patients. The hypothesis that higher dietary phosphorus intake and higher phosphorus content per gram of dietary protein intake are each associated with increased mortality in MHD patients was examined. Food frequency questionnaires were used to conduct a cohort study to examine the survival predictability of dietary phosphorus and the ratio of phosphorus to protein intake. At the start of the cohort, Cox proportional hazard regression was used in 224 MHD patients, who were followed for up to 5 years (2001 to 2006). Both higher dietary phosphorus intake and a higher dietary phosphorus to protein ratio were associated with significantly increased death hazard ratios (HR) in the unadjusted models and after incremental adjustments for case-mix, diet, serum phosphorus, malnutrition-inflammation complex syndrome, and inflammatory markers. The HR of the highest (compared with lowest) dietary phosphorus intake tertile in the fully adjusted model was 2.37. Across categories of dietary phosphorus to protein ratios of or =16 mg/g, death HRs were 1.13, 1.00 (reference value), 1.80, and 1.99, respectively. Cubic spline models of the survival analyses showed similar incremental associations. Higher dietary phosphorus intake and higher dietary phosphorus to protein ratios are each associated with increased death risk in MHD patients, even after adjustments for serum phosphorus, phosphate binders and their types, and dietary protein, energy, and potassium intakes.
8. Phytoextraction of excess soil phosphorus
International Nuclear Information System (INIS)
Sharma, Nilesh C.; Starnes, Daniel L.; Sahi, Shivendra V.
2007-01-01
In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils
9. On the mechanism of phosphorus influence on intercrystalline corrosion of stainless steels
International Nuclear Information System (INIS)
Kolotyrkin, Ya.M.; Kasparova, O.V.; Vasyukov, A.B.; Smakhtin, L.A.; Mekhryusheva, L.I.; Bogolyubskij, S.D.
1979-01-01
Products of the dissolving of hardened austenite stainless steels with phosphorus impurities were studied by the quantitative analysis in the state inclined to intercrystalline corrosion (ICC). The Cr20Ni20-type steels served as the object of the study. Electronic-microscopic analysis of foils and carbon cues has shown that the studied steels has a single-phase structure in a hardened state. They undergo ICC after anode etching. ICC is absent in a highly pure steel without phosphorus impurities. The hypothesis which relates ICC of hardened stainless steels to the segregation of phosphorus along grain boundaries is experimentally confirmed. So, one of the ways to increase resistance of hardened stainless steels to ICC is the development of methods impeding phosphorus segregation along grain boundaries or its selective oxidation
10. Phosphorus Additives and Albuminuria in Early Stages of CKD: A Randomized Controlled Trial.
Science.gov (United States)
Chang, Alex R; Miller, Edgar R; Anderson, Cheryl A; Juraschek, Stephen P; Moser, Melissa; White, Karen; Henry, Bobbie; Krekel, Caitlin; Oh, Susan; Charleston, Jeanne; Appel, Lawrence J
2017-02-01
11. Potential Phosphorus Mobilisation in Peat Soils
DEFF Research Database (Denmark)
Forsmann, Ditte M.; Kjærgaard, Charlotte
2012-01-01
peat soils before a re-establishment takes place. The potential phosphorus mobilisation from a peat soil depends not only on the geochemical characteristics but also on the redox conditions, the hydrological regime in the area as well as the hydro-physical properties of the soil. The hypothesis...... on intact soil samples from each of the 10 locations. As a result the geochemical key parameters controlling the potential phosphorus release from peat soils has been pointed out. Furthermore, it has been emphasised how much the hydro-physical properties influence the potential phosphorus mobilisation from......Re-establishment of wetlands on peat soils containing phosphorus bound to iron(III)-oxides can lead to an undesirable phosphorus loss to the aquatic environment due to the reductive dissolution of iron(III)-oxides. Thus it is important to be able to assess the potential phosphorus mobilisation from...
12. Electron spin resonance studies of γ-irradiated phosphorus compounds containing phosphorus--chlorine bonds
International Nuclear Information System (INIS)
Kerr, C.M.L.; Webster, K.; Williams, F.
1975-01-01
ESR experiments similar to those described in the preceding paper were used to identify the radicals produced in a series of γ-irradiated phosphorus compounds containing phosphorus--chlorine bonds. The principal species formed from diethyl chlorophosphite are the neutral radicals P(OEt) 2 and (EtO) 2 PCl 2 presumably by loss and addition of chlorine atoms, although there is evidence that the former species is produced at least in part by dissociative electron capture. On the other hand, the major radical derived from a series of chlorophosphate esters is invariably the chlorophosphoranyl radical anion formed by simple electron attachment to the parent molecule. In the dichlorophosphoranyl radicals, there is a large 35 Cl coupling from the two equivalent chlorines in the apical positions of a trigonal bipyramidal structure. Evidence for the anisotropy of this coupling suggests that a significant spin density resides in the 3p/sub sigma/ orbitals of these chlorine ligands, in agreement with recent single crystal studies on POCl 3 - . The much greater stability of radical anions derived from chlorophosphates relative to those from di- and trialkyl phosphate esters, which undergo efficient dissociation, is interpreted in terms of the effect of ligand electronegativity on the spin density distribution. This effect is consistent with recent MO descriptions which indicate that the half-occupied orbital in phosphoranyl radicals is largely localized along the axial three-center bond
13. Ionization cross section of partially ionized hydrogen plasma
Energy Technology Data Exchange (ETDEWEB)
Baimbetov, F B; Kudyshev, Z A [Department of Physics, al - Farabi Kazakh National University, Almaty (Kazakhstan)], E-mail: [email protected], E-mail: [email protected]
2008-05-01
In present work the electron impact ionization cross section is considered. The electron impact ionization cross section is calculated, based on pseudopotential model of interaction between plasma particles which accounts correlation effects. It is calculated with help of two methods: classical and quantum - mechanical (Born approximation). The ionization cross section is compared with corresponding results of other authors and experimental data. It has been shown that it is very important to take into account an influence of the surrounding during consideration of ionization processes.
14. Ionization of anisothermal plasmas
International Nuclear Information System (INIS)
Dennery, F.M.
1994-01-01
During this last mid-century, only the temperature of electrons has been involved in the Saha's mass action law, whatever be the other ionic and neutral ones in any isothermal or anisothermal plasma. In order to set aside this underlying paradox in the case of argon ionization, it is necessary to improve this equation of partial equilibrium after having defined: - the basic Gibbs-Duhem's relations for such a polythermal mixture, - the inhomogeneous equilibrium issued from chemical reactions according to Le Chatelier's principle. (author). 3 refs
15. Doubly resonant multiphoton ionization
International Nuclear Information System (INIS)
Crance, M.
1978-01-01
A particular case of doubly resonant multiphoton ionization is theoretically investigated. More precisely, two levels quasi-resonant with two successive harmonics of the field frequency are considered. The method used is based on the effective operator formalism first introduced for this problem by Armstrong, Beers and Feneuille. The main result is to show the possibility of observing large interference effects on the width of the resonances. Moreover this treatment allows us to make more precise the connection between effective operator formalism and standard perturbation theory
16. Ionization detectors, ch. 3
International Nuclear Information System (INIS)
Sevcik, J.
1976-01-01
Most measuring devices used in gas chromatography consist of detectors that measure the ionization current. The process is based on the collision of a moving high-energy particle with a target particle that is ionised while an electron is freed. The discussion of the conditions of the collision reaction, the properties of the colliding particles, and the intensity of the applied field point to a unified classification of ionisation detectors. Radioactive sources suitable for use in these detectors are surveyed. The slow-down mechanism, recombination and background current effect are discussed
17. Phosphorus and Nutrition in Chronic Kidney Disease
Directory of Open Access Journals (Sweden)
Emilio González-Parra
2012-01-01
Full Text Available Patients with renal impairment progressively lose the ability to excrete phosphorus. Decreased glomerular filtration of phosphorus is initially compensated by decreased tubular reabsorption, regulated by PTH and FGF23, maintaining normal serum phosphorus concentrations. There is a close relationship between protein and phosphorus intake. In chronic renal disease, a low dietary protein content slows the progression of kidney disease, especially in patients with proteinuria and decreases the supply of phosphorus, which has been directly related with progression of kidney disease and with patient survival. However, not all animal proteins and vegetables have the same proportion of phosphorus in their composition. Adequate labeling of food requires showing the phosphorus-to-protein ratio. The diet in patients with advanced-stage CKD has been controversial, because a diet with too low protein content can favor malnutrition and increase morbidity and mortality. Phosphorus binders lower serum phosphorus and also FGF23 levels, without decreasing diet protein content. But the interaction between intestinal dysbacteriosis in dialysis patients, phosphate binder efficacy, and patient tolerance to the binder could reduce their efficiency.
18. Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options
NARCIS (Netherlands)
Cordell, D.; Rosemarin, A.; Schroder, J.J.; Smit, A.L.
2011-01-01
Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus
19. The multiphoton ionization of uranium hexafluoride
International Nuclear Information System (INIS)
Armstrong, D.P.
1992-05-01
Multiphoton ionization (MPI) time-of-flight mass spectroscopy and photoelectron spectroscopy studies of UF 6 have been conducted using focused light from the Nd:YAG laser fundamental (λ=1064 nm) and its harmonics (λ=532, 355, or 266 nm), as well as other wavelengths provided by a tunable dye laser. The MPI mass spectra are dominated by the singly and multiply charged uranium ions rather than by the UF x + fragment ions even at the lowest laser power densities at which signal could be detected. The laser power dependence of U n+ ions signals indicates that saturation can occur for many of the steps required for their ionization. In general, the doubly-charged uranium ion (U 2+ ) intensity is much greater than that of the singly-charged uranium ion (U + ). For the case of the tunable dye laser experiments, the U n+ (n = 1- 4) wavelength dependence is relatively unstructured and does not show observable resonance enhancement at known atomic uranium excitation wavelengths. The dominance of the U 2+ ion and the absence or very small intensities of UF x + fragments, along with the unsaturated wavelength dependence, indicate that mechanisms may exist other than ionization of bare U atoms after the stepwise photodissociation of F atoms from the parent molecule
20. Plasma production via field ionization
Directory of Open Access Journals (Sweden)
C. L. O’Connell
2006-10-01
Full Text Available Plasma production via field ionization occurs when an incoming particle beam is sufficiently dense that the electric field associated with the beam ionizes a neutral vapor or gas. Experiments conducted at the Stanford Linear Accelerator Center explore the threshold conditions necessary to induce field ionization by an electron beam in a neutral lithium vapor. By independently varying the transverse beam size, number of electrons per bunch, or bunch length, the radial component of the electric field is controlled to be above or below the threshold for field ionization. Additional experiments ionized neutral xenon and neutral nitric oxide by varying the incoming beam’s bunch length. A self-ionized plasma is an essential step for the viability of plasma-based accelerators for future high-energy experiments.
1. The microbial control of phosphorus fluxes in marine sediments
NARCIS (Netherlands)
Steenbergh, A.K.
2012-01-01
This thesis explores how microorganisms affect the release of the key nutrient phosphorus from marine sediments. A detailed understanding of the controls on regeneration of phosphorus from sediments is important because phosphorus availability in surface waters can regulate primary productivity.
2. Impacts of fish on phosphorus budget dynamics of some SA ...
African Journals Online (AJOL)
Impacts of fish on phosphorus budget dynamics of some SA reservoirs: evaluating prospects of 'bottom up' phosphorus reduction in eutrophic systems through fish removal ... Keywords: biomanipulation, biomass sinks, bioturbation, eutrophication management, excretion, fish, phosphorus, recycling, reservoir ecosystems ...
3. News about ionized food identification
International Nuclear Information System (INIS)
Raffi, J.
1995-01-01
The ionizing radiations are used to clean food and increase their preservation life. If a lot of countries permits ionized products commercialization, others are opposed to it. To control the commercial exchanges, check the applied treatment aim and give to the consumers a better information, several ionized food identification methods were perfected and several are about to be recognized as european standards. 4 refs. 3 figs, 1 tab
4. Biology of ionizing radiation effects
International Nuclear Information System (INIS)
1983-01-01
The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr
International Nuclear Information System (INIS)
Legare, I.-M.; Conceicao Cunha, M. da
1976-01-01
6. Low ionization source velocimetric smoke detector
International Nuclear Information System (INIS)
1980-01-01
The low ionization source velocimetric smoke detector described is characterized in that the air ionization system is an alpha emitting radioactive source of very low intensity. This single source is inserted, without causing any corrosion couple, on both sides of a rigid partition separating into two equal volumes the space between the two polarized plates of an air capacitor. This then forms a reference chamber and an analytical chamber. As the assembly of chambers, source and metal frame is contained in an aerated sheet metal cage, the electric capacity of this capacitor varies when detections occur. The variations are sensed and amplified by a transistorized circuit that memorizes the electric background noises of the detector assembly as well as its slow variations and sorts them out from the variations due to the detection, by a simplified velocimetric electric measuring assembly connected upstream of a warning system that it controls [fr
7. Foundations of ionizing radiation dosimetry
International Nuclear Information System (INIS)
Denisenko, O.N.; Pereslegin, I.A.
1985-01-01
8. AISI/DOE Technology Roadmap Program: Behavior of Phosphorus in DRI/HBI During Electric Furnace Steelmaking
Energy Technology Data Exchange (ETDEWEB)
Richard J. Frueham; Christopher P. Manning [email protected]
2001-10-05
Many common scrap substitutes such as direct reduced iron pellets (DRI), hot briquetted iron (HBI), iron carbide, etc., contain significantly higher levels of phosphorus steelmaking for the production of higher quality steels, control of phosphorus levels in the metal will become a concern. This study has developed a more complete understanding of the behavior of phosphorus in DRI during EAF steelmaking, through a thorough investigation of the kinetics and thermodynamics of phosphorus transfer in the EAF based upon laboratory and plant experiments and trials. Laboratory experiments have shown that phosphorus mass transfer between oxide and metallic phases within commercial direct reduced iron pellets occurs rapidly upon melting according to the local equilibrium for these phases. Laboratory kinetic experiments indicate that under certain conditions, phosphorus mass transfer between slag and metal is influenced by dynamic phenomena, which affect the mass transfer coefficient for the reaction and/or the slag metal interfacial area. Plant trials were conducted to directly evaluate the conditions of mass transfer in the electric furnace and to determine the effects of different scrap substitute materials upon the slag chemistry, the behavior of phosphorus in the steel, and upon furnace yield. The data from these trials were also used to develop empirical models for the slag chemistry and furnace temperature as functions of time during a single heat. The laboratory and plant data were used to develop a numerical process model to describe phosphorus transfer in the EAF
9. Extremely-high vacuum pressure measurement by laser ionization
International Nuclear Information System (INIS)
Kokubun, Kiyohide
1991-01-01
Laser ionization method has the very high sensitivity for detecting atoms and molecules. Hurst et al. successfully detected a single Cs atom by means of resonance ionization spectroscopy developed by them. Noting this high sensitivity, the authors have attempted to apply the laser ionization method to measure gas pressure, particularly in the range down to extremely high vacuum. At present, hot cathode ionization gauges are used for measuring gas pressure down to ultrahigh vacuum, however, those have a number of disadvantages. The pressure measurement using lasers does not have such disadvantages. The pressure measurement utilizing the laser ionization method is based on the principle that when laser beam is focused through a lens, the amount of atom or molecule ions generated in the focused space region is proportional to gas pressure. In this paper, the experimental results are presented on the nonresonant multiphoton ionization characteristics of various kinds of gases, the ion detection system with high sensitivity and an extremely high vacuum system prepared for the laser ionization experiment. (K.I.)
10. Dissociative Ionization of Argon Dimer by Intense Femtosecond Laser Pulses.
Science.gov (United States)
Cheng, Qian; Xie, Xiguo; Yuan, Zongqiang; Zhong, Xunqi; Liu, Yunquan; Gong, Qihuang; Wu, Chengyin
2017-05-25
We experimentally and theoretically studied dissociative ionization of argon dimer driven by intense femtosecond laser pulses. In the experiment, we measured the ion yield and the angular distribution of fragmental ions generated from the dissociative ionization channels of (1,1) (Ar 2 2+ → Ar + + Ar + ) and (2,1) (Ar 2 3+ → Ar 2+ + Ar + ) using a cold target recoil ion momentum spectroscopy. The channel ratio of (2,1)/(1,1) is 4.5-7.5 times of the yield ratio of double ionization to single ionization of argon monomer depending on the laser intensity. The measurement verified that the ionization of Ar + is greatly enhanced if there exists a neighboring Ar + separated by a critical distance. In addition, the fragmental ions exhibit an anisotropic angular distribution with the peak along the laser polarization direction and the full width at half maximum becomes broader with increasing laser intensity. Using a full three-dimensional classical ensemble model, we calculated the angle-dependent multiple ionization probability of argon dimer in intense laser fields. The results show that the experimentally observed anisotropic angular distribution of fragmental ions can be attributed to the angle-dependent enhanced ionization of the argon dimer in intense laser fields.
11. Global Fertilizer and Manure, Version 1: Phosphorus Fertilizer Application
Data.gov (United States)
National Aeronautics and Space Administration — The Phosphorus Fertilizer Application dataset of the Global Fertilizer and Manure, Version 1 Data Collection represents the amount of phosphorus fertilizer nutrients...
12. Phosphorus flows to and from Swedish agriculture and food chain.
Science.gov (United States)
Linderholm, Kersti; Mattsson, Jan Erik; Tillman, Anne-Marie
2012-12-01
Phosphorus flows in Swedish agriculture and food chain were studied by material flow analysis. The system studied included agriculture, food consumption, related waste and wastewater from private households and municipal wastewater treatment plants. Swedish farmland had net annual phosphorus inputs of ~12, 600 metric tons (4.1 kg P ha(-1)) in 2008-2010. The total import of phosphorus in food and feed to Sweden exceed imports of phosphorus in fertilizers. Despite strict animal density regulations relating to manure phosphorus content, phosphorus is accumulating on Swedish animal farms. The total quantity of manure produced greatly exceeds imported mineral phosphorus fertilizer and almost equals total phosphorus inputs to Swedish farmland.
13. [Dietary reference intakes of phosphorus].
Science.gov (United States)
Uenishi, Kazuhiro
2012-10-01
Phosphorus (P) exists at the all organs and plays important physiological roles in the body. A wide range of food contains P, which is absorbed at a higher level (60-70%) and its insufficiency and deficiency are rarely found. P is used as food additives in many processed food, where risk of overconsumption could be an issue. P has less evidence in terms of nutrition. P has the adequate intake and the tolerable upper intake level, for risk reduction of health disorders associated with excess intake, at the Dietary Reference Intakes for Japanese (2010 edition).
14. Anthropogenic phosphorus flows in Denmark
DEFF Research Database (Denmark)
Klinglmair, Manfred
Phosphorus (P) is an essential plant nutrient mined from the earth’s crust as phosphate rock. It cannot be substituted, making it a crucial resource for food production. For the EU, future phosphate scarcity is a potential geopolitical and strategic threat. An increasing worldwide phosphate demand...... these processes hold limited informative value. Moreover, it became clear at the outset of the study that there were distinct differences between the P flows across regions of the country, especially between the east, with the largest urban agglomeration, and the northwest. Apart from population and industrial...
15. [Ionizing and non-ionizing radiation (comparative risk estimations)].
Science.gov (United States)
Grigor'ev, Iu G
2012-01-01
The population has widely used mobile communication for already more than 15 years. It is important to note that the use of mobile communication has sharply changed the conditions of daily exposure of the population to EME We expose our brain daily for the first time in the entire civilization. The mobile phone is an open and uncontrollable source of electromagnetic radiation. The comparative risk estimation for the population of ionizing and non-ionizing radiation was carried out taking into account the real conditions of influence. Comparison of risks for the population of ionizing and non-ionizing radiation leads us to a conclusion that EMF RF exposure in conditions of wide use of mobile communication is potentially more harmful than ionizing radiation influence.
16. Reexamining the Phosphorus-Protein Dilemma: Does Phosphorus Restriction Compromise Protein Status?
Science.gov (United States)
St-Jules, David E; Woolf, Kathleen; Pompeii, Mary Lou; Kalantar-Zadeh, Kamyar; Sevick, Mary Ann
2016-05-01
Dietary phosphorus restriction is recommended to help control hyperphosphatemia in hemodialysis patients, but many high-phosphorus foods are important sources of protein. In this review, we examine whether restricting dietary phosphorus compromises protein status in hemodialysis patients. Although dietary phosphorus and protein are highly correlated, phosphorus intakes can range up to 600 mg/day for a given energy and protein intake level. Furthermore, the collinearity of phosphorus and protein may be biased because the phosphorus burden of food depends on: (1) the presence of phosphate additives, (2) food preparation method, and (3) bioavailability of phosphorus, which are often unaccounted for in nutrition assessments. Ultimately, we argue that clinically relevant reductions in phosphorus intake can be made without limiting protein intake by avoiding phosphate additives in processed foods, using wet cooking methods such as boiling, and if needed, substituting high-phosphorus foods for nutritionally equivalent foods that are lower in bioavailable phosphorus. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
17. Independent colimitation for carbon dioxide and inorganic phosphorus.
Directory of Open Access Journals (Sweden)
Elly Spijkerman
Full Text Available Simultaneous limitation of plant growth by two or more nutrients is increasingly acknowledged as a common phenomenon in nature, but its cellular mechanisms are far from understood. We investigated the uptake kinetics of CO(2 and phosphorus of the algae Chlamydomonas acidophila in response to growth at limiting conditions of CO(2 and phosphorus. In addition, we fitted the data to four different Monod-type models: one assuming Liebigs Law of the minimum, one assuming that the affinity for the uptake of one nutrient is not influenced by the supply of the other (independent colimitation and two where the uptake affinity for one nutrient depends on the supply of the other (dependent colimitation. In addition we asked whether the physiological response under colimitation differs from that under single nutrient limitation.We found no negative correlation between the affinities for uptake of the two nutrients, thereby rejecting a dependent colimitation. Kinetic data were supported by a better model fit assuming independent uptake of colimiting nutrients than when assuming Liebigs Law of the minimum or a dependent colimitation. Results show that cell nutrient homeostasis regulated nutrient acquisition which resulted in a trade-off in the maximum uptake rates of CO(2 and phosphorus, possibly driven by space limitation on the cell membrane for porters for the different nutrients. Hence, the response to colimitation deviated from that to a single nutrient limitation. In conclusion, responses to single nutrient limitation cannot be extrapolated to situations where multiple nutrients are limiting, which calls for colimitation experiments and models to properly predict growth responses to a changing natural environment. These deviations from single nutrient limitation response under colimiting conditions and independent colimitation may also hold for other nutrients in algae and in higher plants.
18. Independent Colimitation for Carbon Dioxide and Inorganic Phosphorus
Science.gov (United States)
Spijkerman, Elly; de Castro, Francisco; Gaedke, Ursula
2011-01-01
Simultaneous limitation of plant growth by two or more nutrients is increasingly acknowledged as a common phenomenon in nature, but its cellular mechanisms are far from understood. We investigated the uptake kinetics of CO2 and phosphorus of the algae Chlamydomonas acidophila in response to growth at limiting conditions of CO2 and phosphorus. In addition, we fitted the data to four different Monod-type models: one assuming Liebigs Law of the minimum, one assuming that the affinity for the uptake of one nutrient is not influenced by the supply of the other (independent colimitation) and two where the uptake affinity for one nutrient depends on the supply of the other (dependent colimitation). In addition we asked whether the physiological response under colimitation differs from that under single nutrient limitation. We found no negative correlation between the affinities for uptake of the two nutrients, thereby rejecting a dependent colimitation. Kinetic data were supported by a better model fit assuming independent uptake of colimiting nutrients than when assuming Liebigs Law of the minimum or a dependent colimitation. Results show that cell nutrient homeostasis regulated nutrient acquisition which resulted in a trade-off in the maximum uptake rates of CO2 and phosphorus, possibly driven by space limitation on the cell membrane for porters for the different nutrients. Hence, the response to colimitation deviated from that to a single nutrient limitation. In conclusion, responses to single nutrient limitation cannot be extrapolated to situations where multiple nutrients are limiting, which calls for colimitation experiments and models to properly predict growth responses to a changing natural environment. These deviations from single nutrient limitation response under colimiting conditions and independent colimitation may also hold for other nutrients in algae and in higher plants. PMID:22145031
19. Independent colimitation for carbon dioxide and inorganic phosphorus.
Science.gov (United States)
Spijkerman, Elly; de Castro, Francisco; Gaedke, Ursula
2011-01-01
Simultaneous limitation of plant growth by two or more nutrients is increasingly acknowledged as a common phenomenon in nature, but its cellular mechanisms are far from understood. We investigated the uptake kinetics of CO(2) and phosphorus of the algae Chlamydomonas acidophila in response to growth at limiting conditions of CO(2) and phosphorus. In addition, we fitted the data to four different Monod-type models: one assuming Liebigs Law of the minimum, one assuming that the affinity for the uptake of one nutrient is not influenced by the supply of the other (independent colimitation) and two where the uptake affinity for one nutrient depends on the supply of the other (dependent colimitation). In addition we asked whether the physiological response under colimitation differs from that under single nutrient limitation.We found no negative correlation between the affinities for uptake of the two nutrients, thereby rejecting a dependent colimitation. Kinetic data were supported by a better model fit assuming independent uptake of colimiting nutrients than when assuming Liebigs Law of the minimum or a dependent colimitation. Results show that cell nutrient homeostasis regulated nutrient acquisition which resulted in a trade-off in the maximum uptake rates of CO(2) and phosphorus, possibly driven by space limitation on the cell membrane for porters for the different nutrients. Hence, the response to colimitation deviated from that to a single nutrient limitation. In conclusion, responses to single nutrient limitation cannot be extrapolated to situations where multiple nutrients are limiting, which calls for colimitation experiments and models to properly predict growth responses to a changing natural environment. These deviations from single nutrient limitation response under colimiting conditions and independent colimitation may also hold for other nutrients in algae and in higher plants.
20. CIFOG: Cosmological Ionization Fields frOm Galaxies
Science.gov (United States)
Hutter, Anne
2018-03-01
CIFOG is a versatile MPI-parallelised semi-numerical tool to perform simulations of the Epoch of Reionization. From a set of evolving cosmological gas density and ionizing emissivity fields, it computes the time and spatially dependent ionization of neutral hydrogen (HI), neutral (HeI) and singly ionized helium (HeII) in the intergalactic medium (IGM). The code accounts for HII, HeII, HeIII recombinations, and provides different descriptions for the photoionization rate that are used to calculate the residual HI fraction in ionized regions. This tool has been designed to be coupled to semi-analytic galaxy formation models or hydrodynamical simulations. The modular fashion of the code allows the user to easily introduce new descriptions for recombinations and the photoionization rate.
1. Ionization spectra of highly Stark-shifted rubidium Rydberg states
Science.gov (United States)
Grimmel, Jens; Stecker, Markus; Kaiser, Manuel; Karlewski, Florian; Torralbo-Campo, Lara; Günther, Andreas; Fortágh, József
2017-07-01
We report on the observation and numerical calculation of ionization spectra of highly Stark-shifted Rydberg states of rubidium beyond the classical ionization threshold. In the numerical calculations, a complex absorbing potential (CAP) allows us to predict the energy levels and ionization rates of Rydberg states in this regime. Our approach of adjusting the CAP to the external electric field reduces the number of free parameters from one per resonance to a single one. Furthermore, we have measured the ionization spectra of magneto-optically trapped rubidium atoms which are excited to principal quantum numbers of 43 and 70 at various electric fields. The emerging ions are detected using an ion optics. We find good agreement between the numerically and experimentally obtained spectra.
2. Enhancing phosphorus removal in constructed wetlands with ochre from mine drainage treatment.
Science.gov (United States)
Heal, K V; Dobbie, K E; Bozika, E; McHaffie, H; Simpson, A E; Smith, K A
2005-01-01
No single end-use has yet been identified that is capable of consuming the projected production of ochre (mainly iron (III) oxides) from mine drainage treatment. However, the high sorption capacity of ochre for phosphorus (up to 26 mg kg(-1)) means that it could be used in constructed wetlands to enhance phosphorus removal. Laboratory batch experiments showed that coarse-grained ochre removes 90% of all phosphorus forms from sewage effluent after 15 minutes of shaking. From a larger-scale experiment, it is estimated that constructed wetlands with an ochre substrate should remove phosphorus from sewage effluent for up to 200-300 years. The suitability of ochre for phosphorus removal is being investigated at the field scale in a wastewater constructed wetland (175 m2 area) in Berwickshire, UK. The hydraulic and treatment performance of the wetland were monitored for 15 months prior to installation at the inlet in November 2003 of a tank containing approximately 1200 kg ochre. Results so far show that improved hydraulic design is required for ochre to increase the mean phosphorus removal efficiency of the system (27 +/- 28%), but potentially toxic metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, Zn) have not been released from the ochre into the wetland outflow.
3. Determination of phosphorus requirements of Cowpea ( Vigna ...
African Journals Online (AJOL)
This study was conducted to determine the phosphorus requirement of cowpea in two locations in southeastern Nigeria (Bende and Umudike) using sorption isotherm. The method used involved equilibrating 3g of soil in 30mls of 0.01m CaCl2 containing various levels of phosphorus at room temperature for 5 days.
4. Sustainable use of phosphorus: a finite resource.
Science.gov (United States)
Scholz, Roland W; Ulrich, Andrea E; Eilittä, Marjatta; Roy, Amit
2013-09-01
5. Energy and phosphorus recovery from black water
NARCIS (Netherlands)
Graaff, de M.S.; Temmink, B.G.; Zeeman, G.; Buisman, C.J.N.
2011-01-01
Source-separated black water (BW) (toilet water) containing 38% of the organic material and 68% of the phosphorus in the total household waste (water) stream including kitchen waste, is a potential source for energy and phosphorus recovery. The energy recovered, in the form of electricity and heat,
6. Virus production in phosphorus-limited
NARCIS (Netherlands)
Maat, D.S.; van Bleijswijk, J.D.L.; Witte, H.J.; Brussaard, C.P.D.
2016-01-01
Earlier studies show that the proliferation of phytoplankton viruses can be inhibited by depletion of soluble reactive phosphorus (SRP; orthophosphate). In natural marine waters, phytoplankton phosphorus (P) availability is, however, largely determined by the supply rate of SRP (e.g. through
Science.gov (United States)
Thacker, Louis H.
1990-01-01
An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.
International Nuclear Information System (INIS)
2014-01-01
Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques
9. Multiphoton ionization of Uracil
Science.gov (United States)
Prieto, Eladio; Martinez, Denhi; Guerrero, Alfonso; Alvarez, Ignacio; Cisneros, Carmen
2016-05-01
Multiphoton ionization and dissociation of Uracil using a Reflectron time of flight spectrometer was performed along with radiation from the second harmonic of a Nd:YAG laser. Uracil is one of the four nitrogen bases that belong to RNA. The last years special interest has been concentrated on the study of the effects under UV radiation in nucleic acids1 and also in the role that this molecule could have played in the origin and development of life on our planet.2 The MPI mass spectra show that the presence and intensity of the resulting ions strongly depend on the density power. The identification of the ions in the mass spectra is presented. The results are compared with those obtained in other laboratories under different experimental conditions and some of them show partial agreement.3 The present work was supported by CONACYT-Mexico Grant 165410 and DGAPA UNAM Grant IN101215 and IN102613.
10. On the Saha Ionization Equation
On the Saha Ionization Equation. Sushanta Dattagupta. General Article Volume 23 Issue 1 January 2018 pp 41-55. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/023/01/0041-0055. Keywords. Ionization, astrophysics, spectroscopy, chemical reaction, transition state. Abstract.
11. Effect of phosphorus incorporation on morphology and optical properties of ZnO nanorods
International Nuclear Information System (INIS)
Fan, Donghua; Zhang, Rong; Wang, Xianghu
2011-01-01
Graphical abstract: XPS spectra of the P-doped ZnO nanorods: (a) Zn 2p, (b) O 1s, and (c) P 2p spectra. The red curve in c is the Gauss-fitting curve. (d) Raman spectra of P-doped (curve 1) and pure (curve 2) ZnO nanorods. Research highlights: → P-doped ZnO nanorods have been prepared on Si substrates without any catalyst. → The introduction of phosphorus leads to the growth of tapered tip in the nanorods. → The formation of tapered tip is attributed to the relaxation of the lattice strain along the radial direction. → The strong ultraviolet peak is connected with the phosphorus acceptor-related emissions. -- Abstract: Phosphorus-doped ZnO nanorods have been prepared on Si substrates by thermal evaporation process without any catalyst. X-ray photoelectron spectroscopy and Raman spectra indicate that phosphorus entering into ZnO nanorods mainly occupies Zn site rather than O one. The introduction of phosphorus leads to the morphological changes of nanorods from hexagonal tip to tapered one, which should be attributed to the relaxation of the lattice strain caused by phosphorus occupying Zn site along the radial direction. Transmission electron microscopy shows that phosphorus-doped ZnO nanorods still are single crystal and grow along [0 0 0 1] direction. The effect of phosphorous dopant on optical properties of ZnO nanorods also is studied by the temperature-dependent photoluminescence spectra, which indicates that the strong ultraviolet emission is connected with the phosphorus acceptor-related emissions.
12. Determination of phosphorus using derivative neutron activation
International Nuclear Information System (INIS)
Scindia, Y.M.; Nair, A.G.C.; Reddy, A.V.R.; Manohar, S.B.
2002-01-01
For the determination of phosphorus in different matrices, the derivative neutron activation analysis is especially applicable to aqueous samples, since the conventional neutron activation analysis is not useful for the determination of phosphorus. Phosphorus when reacted with ammonium molybdate 4 hydrate and ammonium metavanadate forms molybdo vanado phosphoric acid. This complex is preconcentrated by extracting into methyl isobutyl ketone. The organic phase containing the molybdo vanado phosphoric acid is neutron activated and the phosphorus is determined through the activation product of 52 V. Preparation of this complex, its stoichiometry, application to trace level determination of phosphorus and improved detection limit are discussed. This method was applied for the analysis of industrial effluent samples. (author)
13. Ionization detection system for aerosols
International Nuclear Information System (INIS)
Jacobs, M.E.
1977-01-01
This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber. 8 claims, 7 figures
14. Phosphorus Regulation in Chronic Kidney Disease.
Science.gov (United States)
Suki, Wadi N; Moore, Linda W
2016-01-01
Serum phosphorus levels stay relatively constant through the influence of multiple factors-such as parathyroid hormone, fibroblast growth factor 23, and vitamin D-on the kidney, bone, and digestive system. Whereas normal serum phosphorus ranges between 3 mg/dL to 4.5 mg/dL, large cross-sectional studies have shown that even people with normal kidney function are sometimes found to have levels ranging between 1.6 mg/dL and 6.2 mg/dL. While this may partially be due to diet and the factors mentioned above, total understanding of these atypical ranges of serum phosphorus remains uncertain. Risks for bone disease are high in people aged 50 and older, and this group comprises a large proportion of people who also have chronic kidney disease. Consuming diets low in calcium and high in phosphorus, especially foods with phosphate additives, further exacerbates bone turnover. Existing bone disease increases the risk for high serum phosphorus, and higher serum phosphorus has been associated with increased adverse events and cardiovascular-related mortality both in people with chronic kidney disease and in those with no evidence of disease. Once kidney function has deteriorated to end-stage disease (Stage 5), maintaining normal serum phosphorus requires dietary restrictions, phosphate-binding medications, and dialysis. Even so, normal serum phosphorus remains elusive in many patients with Stage 5 kidney disease, and researchers are testing novel targets that may inhibit intestinal transport of phosphorus to achieve better phosphate control. Protecting and monitoring bone health should also aid in controlling serum phosphorus as kidney disease advances.
15. Highly informative multiclass profiling of lipids by ultra-high performance liquid chromatography - Low resolution (quadrupole) mass spectrometry by using electrospray ionization and atmospheric pressure chemical ionization interfaces.
Science.gov (United States)
Beccaria, Marco; Inferrera, Veronica; Rigano, Francesca; Gorynski, Krzysztof; Purcaro, Giorgia; Pawliszyn, Janusz; Dugo, Paola; Mondello, Luigi
2017-08-04
A simple, fast, and versatile method, using an ultra-high performance liquid chromatography system coupled with a low resolution (single quadrupole) mass spectrometer was optimized to perform multiclass lipid profiling of human plasma. Particular attention was made to develop a method suitable for both electrospray ionization and atmospheric pressure chemical ionization interfaces (sequentially in positive- and negative-ion mode), without any modification of the chromatographic conditions (mobile phase, flow-rate, gradient, etc.). Emphasis was given to the extrapolation of the structural information based on the fragmentation pattern obtained using atmospheric pressure chemical ionization interface, under each different ionization condition, highlighting the complementary information obtained using the electrospray ionization interface, of support for related molecule ions identification. Furthermore, mass spectra of phosphatidylserine and phosphatidylinositol obtained using the atmospheric pressure chemical ionization interface are reported and discussed for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.
16. Factors controlling phosphorus release from sediments in coastal archipelago areas.
Science.gov (United States)
Puttonen, Irma; Kohonen, Tuula; Mattila, Johanna
2016-07-15
17. Ionization effects in electronic inner-shells of ionized atoms
International Nuclear Information System (INIS)
Shchornak, G.
1983-01-01
A review of the atomic physics of ionization atoms has been presented. Interaction and structure effects in atomic shells, correlated to the occurrence of vacancies in several subshells of the atom have been considered. The methods of calculations of atomic states and wave functions have been reviewed. The energy shift of characteristic X-rays is discussed as a function of the ionization stage of the atom. The influence of inner and outer-shell vacancies on the energy of the X-rays is shown in detail. The influence of chemical effects on the parameters of X-rays is also taken into account. Further on, the change of transition probabilities in radiative and non-radiative transitions by changing stage of ionization is discussed; and among them the leading part of Auger and Coster-Kronig transitions by the arearrangement of the atomic states is shown. The influence of non-radiative electronic transitions on ionization cross-sections for multiple ionization is discussed. Using these results, ionization cross-sections for direct and indirect processes for several ionization stages are given
18. Phosphorus metabolism and estimation of phosphorus requirements for sheep
International Nuclear Information System (INIS)
Louvandini, H.; Vitti, D.M.S.S.
1996-01-01
The main objective of the present work was to determine the effects of different dietary phosphorus (P) levels on endogenous faecal loss and to estimate the minimum daily requirement of P for sheep. The study was conducted with 24 Suffolk sheep which received a basic diet consisting of a hay-concentrate mixture. The treatment consisted of different amounts of bone meal, added to the basic diet, so as to obtain supplementary P levels of 0, 2 and 3 g/day. Twenty-one days after the introduction of the experimental diet, 7.4 MBq radioactive P ( 32 P) was injected in the left jugular vein of each sheep and blood, feces and urine were collected daily for 8 days at 24-hour intervals. The samples were analysed for inorganic P and for radioactive specific activities. Mean endogenous faecal losses of P were 10.00, 31.79, 39.35 and 38.06 mg/kg live weight (LW) per day in sheep supplemented with 0, 1, 2 and 3 g respectively. A positive linear relation ship was observed between endogenous faecal loss and consumed P, indicating that this loss was linked to dietary P. Total P excretion in the faeces, as well as P absorption, retention urinary excretion and salivary secretion were also directly related to P intake, as part of the mechanism of homeostatic control of organism animal. The minimum endogenous faecal loss for zero P intake, calculated by interpolation, was 8.27 mg/kg LW per day, and for zero balance, the calculated phosphorus consumption was 21.36 mg/kg LW per day. (author)
19. Phosphorus metabolism and estimation of phosphorus requirements for sheep
Energy Technology Data Exchange (ETDEWEB)
Louvandini, H.; Vitti, D.M.S.S. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)
1996-01-01
The main objective of the present work was to determine the effects of different dietary phosphorus (P) levels on endogenous faecal loss and to estimate the minimum daily requirement of P for sheep. The study was conducted with 24 Suffolk sheep which received a basic diet consisting of a hay-concentrate mixture. The treatment consisted of different amounts of bone meal, added to the basic diet, so as to obtain supplementary P levels of 0, 2 and 3 g/day. Twenty-one days after the introduction of the experimental diet, 7.4 MBq radioactive P ({sup 32} P) was injected in the left jugular vein of each sheep and blood, feces and urine were collected daily for 8 days at 24-hour intervals. The samples were analysed for inorganic P and for radioactive specific activities. Mean endogenous faecal losses of P were 10.00, 31.79, 39.35 and 38.06 mg/kg live weight (LW) per day in sheep supplemented with 0, 1, 2 and 3 g respectively. A positive linear relation ship was observed between endogenous faecal loss and consumed P, indicating that this loss was linked to dietary P. Total P excretion in the faeces, as well as P absorption, retention urinary excretion and salivary secretion were also directly related to P intake, as part of the mechanism of homeostatic control of organism animal. The minimum endogenous faecal loss for zero P intake, calculated by interpolation, was 8.27 mg/kg LW per day, and for zero balance, the calculated phosphorus consumption was 21.36 mg/kg LW per day. (author). 12 refs., 7 figs., 1 tab.
20. Ionization efficiency studies for xenon ions with thesuperconducting ECR ion source VENUS
Energy Technology Data Exchange (ETDEWEB)
Leitner, Daniela; Lyneis, Claude M.; Todd, DamonS.; Tarvainen,Olli
2007-06-05
Ionization efficiency studies for high charge state xenon ions using a calibrated gas leak are presented. A 75% enriched {sup 129}Xe gas leak with a gas flow equivalent to 5.11p{mu}A was used in all the measurements. The experiments were performed at the VENUS (Versatile ECR ion source for Nuclear Science) ion source for 18 GHz, 28 GHz and double frequency operation. Overall, total ionization efficiencies close to 100% and ionization efficiencies into a single charge state up to 22% were measured. The influence of the biased disk on the ionization efficiency was studied and the results were somewhat surprising. When the biased disk was removed from the plasma chamber, the ionization efficiency was dramatically reduced for single frequency operation. However, using double frequency heating the ionization efficiencies achieved without the biased disk almost matched the ionization efficiencies achieved with the biased probe. In addition, we have studied the influence of the support gas on the charge state distribution of the xenon ions. Either pure oxygen or a mixture of oxygen and helium were used as support gases. The addition of a small amount of helium can increase the ionization efficiency into a single charge state by narrowing the charge state distribution. Furthermore by varying the helium flow the most efficient charge state can be shifted over a wide range without compromising the ionization efficiency. This is not possible using only oxygen as support gas. Results from these studies are presented and discussed.
1. Hidden sources of phosphorus: presence of phosphorus-containing additives in processed foods.
Science.gov (United States)
Lou-Arnal, Luis M; Arnaudas-Casanova, Laura; Caverni-Muñoz, Alberto; Vercet-Tormo, Antonio; Caramelo-Gutiérrez, Rocío; Munguía-Navarro, Paula; Campos-Gutiérrez, Belén; García-Mena, Mercedes; Moragrera, Belén; Moreno-López, Rosario; Bielsa-Gracia, Sara; Cuberes-Izquierdo, Marta
2014-01-01
An increased consumption of processed foods that include phosphorus-containing additives has led us to propose the following working hypothesis: using phosphate-rich additives that can be easily absorbed in processed foods involves a significant increase in phosphorus in the diet, which may be considered as hidden phosphorus since it is not registered in the food composition tables. The quantity of phosphorus contained in 118 processed products was determined by spectrophotometry and the results were contrasted with the food composition tables of the Higher Education Centre of Nutrition and Diet, those of Morandeira and those of the BEDCA (Spanish Food Composition Database) Network. Food processing frequently involves the use of phosphoric additives. The products whose label contains these additives have higher phosphorus content and higher phosphorus-protein ratio. We observed a discrepancy with the food composition tables in terms of the amount of phosphorus determined in a sizeable proportion of the products. The phosphorus content of prepared refrigerated foods hardly appears in the tables. Product labels provide little information on phosphorus content. We observed a discrepancy in phosphorus content in certain foods with respect to the food composition tables. We should educate our patients on reviewing the additives on the labels and on the limitation of processed foods. There must be health policy actions to deal with the problem: companies should analyse the phosphorus content of their products, display the correct information on their labels and incorporate it into the food composition tables. Incentives could be established to prepare food with a low phosphorus content and alternatives to phosphorus-containing additives.
2. Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution
Directory of Open Access Journals (Sweden)
B. O. L. Demars
2005-01-01
Full Text Available In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years. In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001, were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The calibrated model explained 79% and 89% of the observed variance before and after phosphorus control, respectively. A split test revealed that predicted TP loads were in good agreement with observed TP loads (r2=0.85, although TP loads were underestimated under high flow conditions. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. This was despite a relatively modest critical discharge (Q above which net remobilisation occur. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works reduced phosphorus retention but not the remobilisation. This may indicate that the presence of impoundments and weirs, or overbank flows may have more control on the phosphorus dynamics under high flow conditions. Further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occurring independently of the unpredictable variability in weather conditions. More research is also needed to quantify the impact of the weir and overbank flows on phosphorus dynamics.
3. Bifunctional Phosphorus Dendrimers and Their Properties.
Science.gov (United States)
2016-04-23
Dendrimers are hyperbranched and monodisperse macromolecules, generally considered as a special class of polymers, but synthesized step-by-step. Most dendrimers have a uniform structure, with a single type of terminal function. However, it is often desirable to have at least two different functional groups. This review will discuss the case of bifunctional phosphorus-containing dendrimers, and the consequences for their properties. Besides the terminal functions, dendritic structures may have also a function at the core, or linked off-center to the core, or at the core of dendrons (dendritic wedges). Association of two dendrons having different terminal functions leads to Janus dendrimers (two faces). The internal structure can also possess functional groups on one layer, or linked to one layer, or on several layers. Finally, there are several ways to have two types of terminal functions, besides the case of Janus dendrimers: either each terminal function bears two functions sequentially, or two different functions are linked to each terminal branching point. Examples of each type of structure will be given in this review, as well as practical uses of such sophisticated structures in the fields of fluorescence, catalysis, nanomaterials and biology.
4. Prevalence of phosphorus containing food additives in grocery stores
Directory of Open Access Journals (Sweden)
Janeen B. Leon
2012-06-01
In conclusion, phosphorus additives are commonly present in groceries and contribute significantly to the phosphorus content of foods. Moreover, phosphorus additive foods are less costly than additive-free foods. As a result, phosphorus additives may be an important contributor to hyperphosphatemia among persons with chronic kidney disease
5. 77 FR 46298 - Phosphorus Water Quality Standards for Florida Everglades
Science.gov (United States)
2012-08-03
... complete rulemaking for the Phosphorus Rule within 120 days from the date of the Amended Determination and... Phosphorus Water Quality Standards for Florida Everglades AGENCY: Environmental Protection Agency (EPA... Quality Standards for Phosphorus in the Everglades Protection Area (Phosphorus Rule) and Florida's Amended...
6. Influence of integrated phosphorus supply and plant growth ...
African Journals Online (AJOL)
To guarantee a sufficient phosphorus supply for plants, a rapid and permanent mobilization of phosphorus from the labile phosphorus fractions is necessary, because phosphorus concentrations in soil solution are generally low. Several plant growth-promoting rhizobacteria (PGPR) have shown potential to enhance ...
7. 49 CFR 173.188 - White or yellow phosphorus.
Science.gov (United States)
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false White or yellow phosphorus. 173.188 Section 173... Class 7 § 173.188 White or yellow phosphorus. Phosphorus, white or yellow, when offered for... pound) of phosphorus with screw-top closures; or (2) Steel drums (1A1) not over 250 L (66 gallons...
8. 21 CFR 862.1580 - Phosphorus (inorganic) test system.
Science.gov (United States)
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Phosphorus (inorganic) test system. 862.1580... Systems § 862.1580 Phosphorus (inorganic) test system. (a) Identification. A phosphorus (inorganic) test system is a device intended to measure inorganic phosphorus in serum, plasma, and urine. Measurements of...
9. Ionization Mechanism of Matrix-Assisted Laser Desorption/Ionization
Science.gov (United States)
Lu, I.-Chung; Lee, Chuping; Lee, Yuan-Tseh; Ni, Chi-Kung
2015-07-01
In past studies, mistakes in determining the ionization mechanism in matrix-assisted laser desorption/ionization (MALDI) were made because an inappropriate ion-to-neutral ratio was used. The ion-to-neutral ratio of the analyte differs substantially from that of the matrix in MALDI. However, these ratios were not carefully distinguished in previous studies. We begin by describing the properties of ion-to-neutral ratios and reviews early experimental measurements. A discussion of the errors committed in previous theoretical studies and a comparison of recent experimental measurements follow. We then describe a thermal proton transfer model and demonstrate how the model appropriately describes ion-to-neutral ratios and the total ion intensity. Arguments raised to challenge thermal ionization are then discussed. We demonstrate how none of the arguments are valid before concluding that thermal proton transfer must play a crucial role in the ionization process of MALDI.
10. Multiple ionization of noble gases by 2.0 MeV proton impact: comparison with equi-velocity electron impact ionization
International Nuclear Information System (INIS)
Melo, W.S.; Santos, A.C.F.; Sant'Anna, M.M.; Sigaud, G.M.; Montenegro, E.C.
2002-01-01
Absolute single- and multiple-ionization cross sections of rare gases (He, Ne, Ar, Kr and Xe) have been measured for collisions with 2.0 MeV p + . A comparison is made with equi-velocity electron impact ionization cross sections as well as with the available proton impact data. For the light rare gases the single-ionization cross sections are essentially the same for both proton and electron impacts, but increasing differences appear for the heavier targets. (author). Letter-to-the-editor
11. Photoionization effects in ionization fronts
Energy Technology Data Exchange (ETDEWEB)
Arrayas, Manuel [Departamento de Electromagnetismo, Universidad Rey Juan Carlos, Tulipan s/n, 28933 Mostoles, Madrid (Spain); Fontelos, Marco A [Departamento de Matematicas, Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, C/Serrano 123, 28006 Madrid (Spain); Trueba, Jose L [Departamento de Electromagnetismo, Universidad Rey Juan Carlos, Tulipan s/n, 28933 Mostoles, Madrid (Spain)
2006-12-21
In this paper we study the effects of photoionization processes on the propagation of both negative and positive ionization fronts in streamer discharge. We show that negative fronts accelerate in the presence of photoionization events. The appearance and propagation of positive ionization fronts travelling with constant velocity is explained as the result of the combined effects of photoionization and electron diffusion. The photoionization range plays an important role in the selection of the velocity of the ionization front as we show in this work.
12. Pulsed helium ionization detection system
Science.gov (United States)
Ramsey, R.S.; Todd, R.A.
1985-04-09
A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.
13. Single and double [ital K]-shell ionization and electron-transfer cross sections for Fe and Ni bombarded by S ions and Fe by Si ions at 1. 25--4. 70 MeV/amu
Energy Technology Data Exchange (ETDEWEB)
Tribedi, L.C.; Prasad, K.G.; Tandon, P.N. (Tata Institute of Fundamental Research, Bombay 400005 (India)); Chen, Z.; Lin, C.D. (Department of Physics, Kansas State University, Manhattan, Kansas (United States))
1994-02-01
Single and double [ital K]-shell vacancy production and [ital K]-[ital K] electron-transfer cross sections have been measured in the limit of zero target thickness for Fe and Ni induced by 1.25--4.70 MeV/amu [sup 28]Si and [sup 32]S ions. The fluorescence yield [omega][sub [ital k
14. Ionization of liquids
International Nuclear Information System (INIS)
Gregg, E.C.; Bakale, G.
1976-01-01
Application of pulsed-conductivity techniques to ionization phenomena in liquids has yielded new results on electron transport and electron reactions in nonpolar liquids which we have extrapolated to biological systems to develop a novel model of direct radiation damage to mammalian cells that involves the unsolvated electron as the key reactant. Among these new results are electron attachment rate constants of thirty-five substituted nitrobenzene compounds measured in nonpolar solvents which when combined with product anion lifetimes are correlated with cellular radiosensitization efficiencies. From this study we found that electron attachment rates are dependent upon the electron mobility in the solvents and upon the dipole moment of the electron-accepting nitrobenzene compounds. The model also drawn upon energy-dependent electron attachment rates which we have measured in cryogenic liquids, and we have measured in the same solvents associative detachment rate constants and electron momentum transfer cross sections. In addition to these studies of electronic processes in liquids, we have measured ion mobilities of lecithin and chlorophyll in nonpolar solvents and conclude that these solutes form inverse micelles under certain conditions. Formation of these micelles permits electron transport through the lipid micellar walls and electron attachment to electron-accepting polar solutes inside the lipid vesicles to be studied
15. Ionization in liquids
International Nuclear Information System (INIS)
Bakale, G.
1990-01-01
During the 1987--1990 reporting period, studies were conducted that entailed the direct measurement of the transport and reaction properties of excess electrons in nonpolar liquids through the use of pulse-conductivity techniques. The results obtained from these studies should be applicable toward the development of a better understanding of the primary ionizing event in liquids as well as to providing physico-chemical information that is pertinent to electron-transfer processes that are ubiquitous in biological systems. Progress was also made in developing a better understanding of electron attachment reactions in liquids through measurements of the electron attachment rate constants, k e s, of a variety of electron-attaching solutes. The effects of several functional groups substituted at different positions on benzene were studied in liquid cyclohexane and isooctane. The electron-attaching properties of chemicals having well characterized carcinogenic properties were studied in cyclohexane to determine if the measure of electron-accepting potential that k e provides can elucidate the role that electrons play in the initiation step of carcinogenesis. The k e s that were measured indicate that the k e -carcinogenicity correlation that was observed can be used to complement short-term carcinogen-screening bioassays to identify potential carcinogens. 115 refs., 6 tabs
International Nuclear Information System (INIS)
1984-05-01
17. Lake Erie, phosphorus and microcystin: Is it really the farmer's fault?
Science.gov (United States)
Agricultural loss of phosphorus (P) have been identified as a primary contributor to eutrophication and the associated release of toxins (i.e., mycrocystin) in Lake Erie. These losses are commonly deemed excessive by the media and the public, singling out agriculture as the culprit in spite of redu...
18. Low-to-moderate nitrogen and phosphorus concentrations accelerate microbially driven litter breakdown rates
Science.gov (United States)
John S. Kominoski; Amy D. Rosemond; Jonathan P. Benstead; Vladislav Gulis; John C. Maerz; David Manning
2015-01-01
Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-...
19. Measurement of phosphorus in metals by RNAA
International Nuclear Information System (INIS)
Paul, R.L.
2000-01-01
An RNAA procedure has been developed for measurement of low-level phosphorus in metals. Samples are irradiated at a neutron flux of 2.7 x 10 13 n x cm -2 x s -1 then mixed with carrier and dissolved in acid. After chemical separation and purification of the phosphorus and gravimetric determination of carrier yield, 32 P is determined using a beta proportional counter. The detection limit for a 0.1 g sample irradiated for 30 minutes is 5 μg/kg. The method has been used to determine 6.4 ± 0.6 mg/kg phosphorus is SRM 2175 refractory alloy. (author)
20. Radiochemical analysis of phosphorus in milk samples
International Nuclear Information System (INIS)
Oliveira, R.M. de; Cunha, I.I.L.
1991-01-01
The determination of phosphorus in milk samples by thermal neutron activation analysis employing radiochemical separation is described. The radiochemical separation consists of the simultaneous irradiation of samples and standards, dissolution of the milk samples in a perchloric acid and nitric acid mixture, addition of zinc hold-back carrier, precipitation of phosphorus as ammonium phospho molybdate (A.M.P.) and sample counting in a Geiger-Mueller detector. The analysis sources of error were studied and the established method was applied to phosphorus analyses in commercial milk samples. (author)
1. Use of Phosphorus Isotopes for Improving Phosphorus Management in Agricultural Systems
International Nuclear Information System (INIS)
2016-10-01
Phosphorus is an essential element in plant, human and animal nutrition. Soils with low levels of phosphorus are widespread in many regions of the world, and the deficiency limits plant growth and reduces crop production and food quality. This publication provides comprehensive and up to date information on several topics related to phosphorus in soil–plant systems, in agricultural systems and in the environment. It presents the theoretical background as well as practical information on how to use nuclear and radioisotope tracer techniques in both laboratory and greenhouse experiments to assess soil phosphorus forms and plant-available soil phosphorus pools, and to understand the cycling processes in soil–plant systems. The publication focuses on practical applications of radiotracer techniques and can serve as resource material for research projects on improving sustainable phosphorus management in agricultural systems and as practical guidance on the use of phosphate isotopes in soil–plant research
2. Ionization of a multilevel atom by ultrashort laser pulses
International Nuclear Information System (INIS)
Andreev, A. V.; Stremoukhov, S. Yu.; Shutova, O. A.
2010-01-01
Specific features of ionization of single atoms by laser fields of a near-atomic strength are investigated. Calculations are performed for silver atoms interacting with femtosecond laser pulses with wavelengths λ = 800 nm (Ti:Sapphire) and λ = 1.064 μm (Nd:YAG). The dependences of the probability of ionization and of the form of the photoelectron energy spectra on the field of laser pulses for various values of their duration are considered. It is shown that the behavior of the probability of ionization in the range of subatomic laser pulse fields is in good agreement with the Keldysh formula. However, when the field strength attains values close to the atomic field strength, the discrepancies in these dependences manifested in a decrease in the ionization rate (ionization stabilization effect) or in its increase (accelerated ionization) are observed. These discrepancies are associated with the dependence of the population dynamics of excited discrete energy levels of the atom on the laser pulse field amplitude.
3. Ionized calcium serum evaluation in unilateral thyroidectomized cats
Directory of Open Access Journals (Sweden)
Katia Barão Corgozinho
2015-12-01
Full Text Available ABSTRACT. Corgozinho K.B., Cunha S.C.S., Neves A.P., Belchior C., Damico C.B., Silva C.A., Souza H.J.M.& Ferreira A.M.R. [Ionized calcium serum evaluation in unilateral thyroidectomized cats.] Avaliação do cálcio ionizado em gatos submetidos a tireoidectomia unilateral. Revista Brasileira de Medicina Veterinária 37(4:345-349, 2015. Pós-Graduação em Clínica e Reprodução Animal, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brasil Filho, 64, Niterói, RJ 24230-340, Brasil. E-mail: [email protected] Seventeen hyperthyroid cats with cervical palpable nodules were submitted to clinical and laboratorial examination and they were prepared to surgery. Unilateral thyroparathyroidectomy with parathyroid gland autotransplantation was performed. Concentrations of serum urea, creatinine, alkaline phosphatase, alanine aminotransferase, phosphorus, potassium, total thyroxine and hematologic profile were determined before and seven days after surgery. Blood samples for serum ionized calcium concentration were collected before and after surgery on days 1, 2, 7, 15, 21. All cats had ionized calcium concentration within the reference range before surgery. Serum calcium concentration fell significantly in all cats within 24 hours after surgery. Hypocalcemia occurred in two cats without clinical signs. Ionized calcium concentration decreased after surgery and returned to normal levels on day 7 postoperatively. The results of this study suggest that calcium concentration must be measured before surgery in cats submitted to thyroidectomy even if they are submitted to unilateral technique.
4. Assessing the Long Term Impact of Phosphorus Fertilization on Phosphorus Loadings Using AnnAGNPS
OpenAIRE
Yuan, Yongping; Bingner, Ronald L.; Locke, Martin A.; Stafford, Jim; Theurer, Fred D.
2011-01-01
High phosphorus (P) loss from agricultural fields has been an environmental concern because of potential water quality problems in streams and lakes. To better understand the process of P loss and evaluate the effects of different phosphorus fertilization rates on phosphorus losses, the USDA Annualized AGricultural Non-Point Source (AnnAGNPS) pollutant loading model was applied to the Ohio Upper Auglaize watershed, located in the southern portion of the Maumee River Basin. In this study, the ...
5. Effect of Co-60 gamma irradiated chitosan and phosphorus fertilizer on growth, yield and trigonelline content of Trigonella foenum-graecum L.
Directory of Open Access Journals (Sweden)
2015-07-01
Full Text Available Natural marine polysaccharides such as chitosan, sodium alginate and carrageenan; after depolymerization by different techniques, have shown promising plant growth promoting and other biological activities. Chitosan after irradiation with Co-60 gamma-rays have proven to be a miraculous plant growth promoter in different plants. Trigonelline; an anti-diabetic compound is obtained mainly from the seeds of Fenugreek (Trigonella foenum-graecum L.. Trigonelline counteracts diabetes mellitus (DM through the operation of the mechanisms of insulin secretion, modulation of β-cell regeneration and stimulation of activity of glucose metabolism related enzymes. Considering the medicinal importance a pot experiment was conducted to investigate the effect of foliar application of Co-60 gamma irradiated chitosan (IC with soil applied phosphorus supplement on growth, biochemical and quality attributes of fenugreek. Four concentrations of irradiated chitosan were used (0, 40, 80 and 120 mg L−1 individually as well as in combination with single dose of phosphorus 40 kg ha−1. Un-irradiated chitosan (UN 40 mg L−1 and de-ionized water were used as control. IC significantly affected almost all the parameters including seed yield, trigonelline content and trigonelline yield. There were 10 treatments and among all, P40 + IC 40 mg L−1 proved to be the best, which increased total alkaloid content by 34.9%, seed yield by 125.4%, and trigonelline content by 17.8%. Contents of photosynthetic pigments and activity of nitrate reductase, carbonic anhydrase enzymes were also significantly enhanced.
6. Role for DNA polymerase beta in response to ionizing radiation.
NARCIS (Netherlands)
Vermeulen, C.; Verwijs-Janssen, M.; Cramers, P.; Begg, A.C.; Vens, C.
2007-01-01
Evidence for a role of DNA polymerase beta in determining radiosensitivity is conflicting. In vitro assays show an involvement of DNA polymerase beta in single strand break repair and base excision repair of oxidative damages, both products of ionizing radiation. Nevertheless the lack of DNA
7. Phosphorus K4 Crystal: A New Stable Allotrope
OpenAIRE
Jie Liu; Shunhong Zhang; Yaguang Guo; Qian Wang
2016-01-01
The intriguing properties of phosphorene motivate scientists to further explore the structures and properties of phosphorus materials. Here, we report a new allotrope named K 4 phosphorus composed of three-coordinated phosphorus atoms in non-layered structure which is not only dynamically and mechanically stable, but also possesses thermal stability comparable to that of the orthorhombic black phosphorus (A17). Due to its unique configuration, K 4 phosphorus exhibits exceptional properties: i...
8. Physics of partially ionized plasmas
CERN Document Server
Krishan, Vinod
2016-01-01
Plasma is one of the four fundamental states of matter; the other three being solid, liquid and gas. Several components, such as molecular clouds, diffuse interstellar gas, the solar atmosphere, the Earth's ionosphere and laboratory plasmas, including fusion plasmas, constitute the partially ionized plasmas. This book discusses different aspects of partially ionized plasmas including multi-fluid description, equilibrium and types of waves. The discussion goes on to cover the reionization phase of the universe, along with a brief description of high discharge plasmas, tokomak plasmas and laser plasmas. Various elastic and inelastic collisions amongst the three particle species are also presented. In addition, the author demonstrates the novelty of partially ionized plasmas using many examples; for instance, in partially ionized plasma the magnetic induction is subjected to the ambipolar diffusion and the Hall effect, as well as the usual resistive dissipation. Also included is an observation of kinematic dynam...
9. Efficiency of phosphate fertilization to maize crop in high phosphorus content soil, evaluated by 32P tracer
International Nuclear Information System (INIS)
Trevizam, Anderson R.; Alvarez Villanueva, Felipe C.; Silva, Maria Ligia de S.; Muraoka, Takashi
2007-01-01
Application of high dosis of phosphorus (P) in agricultural soils is justified by its intense fixation by the soil clays, which reduce availability to crops. The objective of this research was to evaluate the response of maize crops to five rates of triple superphosphate in a soil with high available phosphorus content. Portions of 2 dm 3 of soil (Typic Quartzipisamment) with 75 mg kg -1 of available phosphorus and pH 7.00, collected from the upper 0-20 cm layer, were placed in plastic pots, received solution containing 5.55 MBq (150 μCi) of 32 P and incubated for 7 days. Then 0, 250, 500, 1000 and 4000 mg P kg -1 as triple superphosphate was added to soil in the respective pots and incubated for 15 days keeping the soil moisture to 60 % of the field capacity. Maize (Zea mays L.) plants, single hybrid P30F80, were grown for 50 days (after germination), collected, oven dried, weighed and ground in a Wiley mill for analysis of total P content and 32 P radioactivity. The maize dry matter increased with triple superphosphate rates. The phosphorus content and accumulation in the maize plants increased with triple superphosphate rate up to 4000 mg kg -1 . The percentage of phosphorus derived from the fertilizer ranged from 79 to 97% and consequently the phosphorus derived from soil decreased with increasing application of triple superphosphate. In spite of soil high P available content, maize plants responded to applied phosphorus rates. (author)
10. Habitual dietary phosphorus intake and urinary excretion in chronic kidney disease patients: a 3-day observational study.
Science.gov (United States)
Salomo, L; Kamper, A-L; Poulsen, G M; Poulsen, S K; Astrup, A; Rix, M
2017-06-01
Hyperphosphatemia in chronic kidney disease (CKD) is associated with vascular calcification, cardiovascular morbidity and mortality. The aim of this study was to estimate the daily dietary phosphorus intake compared with recommendations in CKD patients and to evaluate the reproducibility of the 24-h urinary phosphorus excretion. Twenty CKD patients stage 3-4 from the outpatient clinic, collected 24-h urine and kept dietary records for 3 consecutive days. The mean daily phosphorus intake was 1367±499, 1642±815 and 1426±706 mg/day, respectively (P=0.57). The mean urinary phosphorus excretion was 914±465, 954±414 and 994±479 mg/day, respectively (P=0.21). In this population of CKD patients stage 3-4 the daily phosphorus intake was above the recommended. Twenty-four-hour urinary phosphorus excretion was reproducible and the data indicate that a single 24-h urine collection is sufficient to estimate the individual phosphorus excretion.
11. Screening crops for efficient phosphorus acquisition in a low phosphorus soil using radiotracer technique
International Nuclear Information System (INIS)
Meena, S.; Malarvizhi, P.; Rajeswari, R.
2017-01-01
Deficiency of phosphorus (P) is the major limitation to agricultural production. Identification of cultivars with greater capacity to grow in soils having low P availability (phosphorus efficiency) will help in P management in a sustainable way. Green house experiment with maize (CO 6) and cotton (MCU 13) as test crops with four levels of phosphorus (0, 3.75, 7.50 and 15 mg P kg -1 soil) was conducted in a P deficient soil (7.2 kg ha -1 ) to study the phosphorus acquisition characteristics and to select efficient crop using 32 P radiotracer technique. Carrier free 32 P obtained as orthophosphoric acid in dilute hydrochloric acid medium from the Board of Radiation and Isotope Technology, Mumbai was used for labeling the soil @ 3200 kBq pot -1 . After 60 days the crops were harvested and the radioactivity was measured in the plant samples using Liquid scintillation counter (PerkinElmer - Tricarb 2810 TR). Different values of specific radioactivity and Isotopically Exchangeable Phosphorus for maize and cotton indicated that chemically different pools of soil P were utilized and maize accessing a larger pool than cotton. Maize having recorded high Phosphorus Use Efficiency, Phosphorus Efficiency and low Phosphorus Stress Factor values, it is a better choice for P deficient soils. Higher Phosphorus Acquisition Efficiency of maize (59 %) than cotton (48%) can be related to the ability of maize to take up P from insoluble inorganic P forms. (author)
12. Resonance ionization for analytical spectroscopy
Science.gov (United States)
Hurst, George S.; Payne, Marvin G.; Wagner, Edward B.
1976-01-01
This invention relates to a method for the sensitive and selective analysis of an atomic or molecular component of a gas. According to this method, the desired neutral component is ionized by one or more resonance photon absorptions, and the resultant ions are measured in a sensitive counter. Numerous energy pathways are described for accomplishing the ionization including the use of one or two tunable pulsed dye lasers.
13. CERI: Ionizing Radiation Calibration Centre
International Nuclear Information System (INIS)
Bouteiller, E.
1979-01-01
The CERI has been granted by the National Bureau of Metrology (BNM) as an Ionizing Radiation Calibration Centre and as an Estimation and Qualification Centre for the ionizing radiation measurement devices. This article gives some information on the scope covered by the BNM's grant and on the various equipment on which the laboratory relies. It describes the calibration and estimation activities and mentions many kinds of services which are offered to the users mainly in the medical and industrial fields [fr
14. Ionizing radiation and cancer prevention.
OpenAIRE
Hoel, D G
1995-01-01
Ionizing radiation long has been recognized as a cause of cancer. Among environmental cancer risks, radiation is unique in the variety of organs and tissues that it can affect. Numerous epidemiological studies with good dosimetry provide the basis for cancer risk estimation, including quantitative information derived from observed dose-response relationships. The amount of cancer attributable to ionizing radiation is difficult to estimate, but numbers such as 1 to 3% have been suggested. Some...
15. New chiral zwitterionic phosphorus heterocycles: synthesis, structure, properties and application as chiral solvating agents.
Science.gov (United States)
Sheshenev, Andrey E; Boltukhina, Ekaterina V; Grishina, Anastasiya A; Cisařova, Ivana; Lyapkalo, Ilya M; Hii, King Kuok Mimi
2013-06-17
A family of new chiral zwitterionic phosphorus-containing heterocycles (zPHC) have been derived from methylene-bridged bis(imidazolines). These structures were unambiguously determined, including single-crystal XRD analysis for two compounds. The stability, acid/base and electronic properties of these dipolar phosphorus heterocycles were subsequently investigated. zPHCs can be successfully employed as a new class of chiral solvating agents for the enantiodifferentiation of chiral carboxylic and sulfonic acids by NMR spectroscopy. The stoichiometry and binding constants for the donor-acceptor complexes formed were established by NMR titration methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
16. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy
Energy Technology Data Exchange (ETDEWEB)
Oberbeck, Lars [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); TOTAL Marketing Services, New Energies, La Défense 10, 92069 Paris La Défense Cedex (France); Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y., E-mail: [email protected], E-mail: [email protected] [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schofield, Steven R. [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, UCL, London WC1E 6BT (United Kingdom); Curson, Neil J., E-mail: [email protected], E-mail: [email protected] [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, UCL, London WC1E 7JE (United Kingdom)
2014-06-23
We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.
17. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy
International Nuclear Information System (INIS)
Oberbeck, Lars; Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y.; Schofield, Steven R.; Curson, Neil J.
2014-01-01
We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.
18. Electrical activation of phosphorus in silicon
International Nuclear Information System (INIS)
Goh, K.E.J.; Oberbeck, L.; Simmons, M.Y.; Clark, R.G.
2003-01-01
Full text: We present studies of phosphorus δ-doping in silicon with a view to determining the degree of electrical activation of the dopants. These results have a direct consequence for the use of phosphorus as a qubit in a silicon-based quantum computer such as that proposed by Kane. Room temperature and 4 K Hall effect measurements are presented for phosphorus δ-doped layers grown in n-type silicon using two different methods. In the first method, the δ-layer was deposited by a phosphorus effusion cell in an MBE chamber. In the second method, the Si surface was dosed with phosphine gas and then annealed to 550 deg C to incorporate P into the substrate. In both methods, the P δ-doped layer was subsequently encapsulated by ∼25 nm of Si grown epitaxially. We discuss the implications of our results on the fabrication of the Kane quantum computer
19. Adaptive Evolution of Phosphorus Metabolism in Prochlorococcus
DEFF Research Database (Denmark)
Casey, John R; Mardinoglu, Adil; Nielsen, Jens
2016-01-01
Inorganic phosphorus is scarce in the eastern Mediterranean Sea, where the high-light-adapted ecotype HLI of the marine picocyanobacterium Prochlorococcus marinus thrives. Physiological and regulatory control of phosphorus acquisition and partitioning has been observed in HLI both in culture...... and in the field; however, the optimization of phosphorus metabolism and associated gains for its phosphorus-limited-growth (PLG) phenotype have not been studied. Here, we reconstructed a genome-scale metabolic network of the HLI axenic strain MED4 (iJC568), consisting of 568 metabolic genes in relation to 794...... reactions involving 680 metabolites distributed in 6 subcellular locations. iJC568 was used to quantify metabolic fluxes under PLG conditions, and we observed a close correspondence between experimental and computed fluxes. We found that MED4 has minimized its dependence on intracellular phosphate, not only...
20. Phosphorus-containing oily waste processing method
International Nuclear Information System (INIS)
1993-01-01
TBP is used, as an extracting agent, in a reprocessing step for spent fuels and phosphoric ester oil is used as a controlling oil in a nuclear power plant, radioactive phosphorus-containing oil wastes are formed. An organic solution containing calcium is added and mixed to the radioactive oil wastes such that the ratio of calcium relative to phosphorus is greater than a stoichiometrical amount, and it is burnt in an incinerator. Combustion exhaustion gases are filtered by a high temperature filter filled with ceramic honeycombs further filtered precisely by an exhaustion gas filter and then released. Since phosphorus-containing oil wastes are mixed with the organic solution containing calcium and burnt in the incinerator, burning can be conducted without generating corrosive phosphoric acid. In addition, phosphorus-containing oil wastes of poor combustion property can be burnt without any trouble, clogging of the high temperature filter is reduced, and no large-sized facility is necessary. (N.H.)
1. Total Phosphorus in Surface Water (Future)
Data.gov (United States)
U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALPFuture is reported in kilograms/hectare/year. More information about these resources,...
2. The phosphorus and the transition metals chemistry
International Nuclear Information System (INIS)
Mathey, F.
1988-01-01
The 1988 progress report, concerning the Polytechnic School unit (France), which studies the phosphorus and the transition metals chemistry, is presented. The laboratory activities are related to the following topics: the phosporus heterocyclic chemistry, the phosphorus-carbon double bonds chemistry, the new transition metals phosphorus compounds, the phosphonates and their uses. Some practical applications of homogeneous catalysis and new materials synthesis are investigated. The main results obtained are: the discovery of the tetra-phosphafulvalenes, the utilization of a new synthesis method of the phosphorus-carbon double bonds and the stabilization of the α-phosphonyled carbanions by the lithium diisopropylamidourea. The papers, the congress communications and the thesis are also shown [fr
3. Phosphorus in antique iron music wire.
Science.gov (United States)
Goodway, M
1987-05-22
Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.
4. Ab Initio Studies on Hexavalent Phosphorus Compounds
National Research Council Canada - National Science Library
Wilson, Ashley L; White, William E
2002-01-01
.... Hartree-Fock calculations were performed on a series of hexavalent phos-phorus compounds in which a nitrogen atom provided both electrons for the sixth bond thereby forming an octahedral complex...
5. Measurement of Anomalously Strong Emission from the 1s-9p Transition in the Spectrum of H-like Phosphorus Following Charge Exchange with Molecular Hydrogen
Science.gov (United States)
Leutenegger, M. A.; Beiersdorfer, P.; Brown, G. V.; Kelley, R. L.; Porter, F. S.
2010-01-01
We have measured K-shell x-ray spectra of highly ionized argon and phosphorus following charge exchange with molecular hydrogen at low collision energy in an electron beam ion trap using an x-ray calorimeter array with approx.6 eV resolution. We find that the emission at the high-end of the Lyman series is greater by a factor of two for phosphorus than for argon, even though the measurement was performed concurrently and the atomic numbers are similar. This does not agree with current theoretical models and deviates from the trend observed in previous measurements.
6. Removal of organic pollutants by surfactant modified zeolite: comparison between ionizable phenolic compounds and non-ionizable organic compounds.
Science.gov (United States)
Xie, Jie; Meng, Wenna; Wu, Deyi; Zhang, Zhenjia; Kong, Hainan
2012-09-15
7. Physicochemical properties of mixed phosphorus halides
International Nuclear Information System (INIS)
1996-01-01
Certain physicochemical properties (thermodynamic characteristics at boiling point, critical constants, density of liquid on the saturation line) of mixed phosphorus halides (PI 3 , PI 2 F, PIF 2 , PI 2 Cl, PICl 2 , PI 1 Br, PIBr 2 , PIClF, PIBrCl, etc.) are determined by means of approximate methods. Reliability of the results obtained is confirmed by comparison of calculated and experimental data for phosphorus compounds of the same type. 7 refs., 3 figs., 4 tabs
8. Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium
Science.gov (United States)
2010-02-01
Carribean ; Romans e al. 1994), the presence of high percentages of polyP in Trichodesmium from the Sargasso Sea is unlikely to be due to luxury uptake...2010-06 DOCTORAL DISSERTATION by Elizabeth Duncan Orchard February 2010 Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium MIT/WHOI...2010-06 Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium by Elizabeth Duncan Orchard Massachusetts Institute of Technology Cambridge
9. Systematics of multielement determination with resonance ionization mass spectrometry and thermal atomization
International Nuclear Information System (INIS)
Moore, L.J.; Fassett, J.D.; Travis, J.C.
1984-01-01
The systematics for multielement determination using resonance ionization mass spectrometry and thermal atomization is developed. The aspects of atomization, ionization, and detection are discussed and resonance ionization is demonstrated for 19 elements. The selective, sequential ionization of seven elements from a single sample is also demonstrated. A one-wavelength, two-photon ionization scheme generally is used in which the first photon excites a bound transition in the near-ultraviolet region and second photon promotes the electron into theionization continuum. The wavelength-dependence ion formation from the thermally produced atom reservoirs is demonstrated for these elements by scanning a Nd:YAG-pumped dye laser across its tunable wavelength range. The observed wavelengths where ionization occurs have been correlated where possible with allowed transitions between known electronic energy levels. The elements accessible by using four common dyes are tabulated. More than 20 elements are accessible within the wavelength range of each dye
10. Classical trajectory perspective of atomic ionization in strong laser fields semiclassical modeling
CERN Document Server
Liu, Jie
2014-01-01
The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers...
11. Effects of white phosphorus on mallard reproduction
Science.gov (United States)
Vann, S.I.; Sparling, D.W.; Ottinger, M.A.
2000-01-01
Extensive waterfowl mortality involving thousands of ducks, geese, and swans has occurred annually at Eagle River Flats, Alaska since at least 1982. The primary agent for this mortality has been identified as white phosphorus. Although acute and subacute lethality have been described, sublethal effects are less well known. This study reports on the effects of white phosphorus on reproductive function in the mallard (Anas platyrhynchos) in captivity. Fertility, hatching success, teratogenicity, and egg laying frequency were examined in 70 adult female mallards who received up to 7 daily doses of 0, 0.5, 1.0, and 2.0 mg/kg of white phosphorus. Measurements of fertility and hatchability were reduced by the white phosphorus. Teratogenic effects were observed in embryos from hens dosed at all treatment levels. Egg laying frequency was reduced even at the lowest treatment level; treated hens required a greater number of days to lay a clutch of 12 eggs than control hens. After two doses at 2.0 mg/kg, all females stopped laying completely for a minimum of 10 days and laying frequency was depressed for at least 45 days. Fertility of 10 adult male mallards dosed with 1.0 mg/kg of white phosphorus did not differ from 10 controls, but plasma testosterone levels were significantly (p free-ranging mallards may be impaired if they are exposed to white phosphorus at typical field levels.
12. Soil phosphorus constrains biodiversity across European grasslands.
Science.gov (United States)
Ceulemans, Tobias; Stevens, Carly J; Duchateau, Luc; Jacquemyn, Hans; Gowing, David J G; Merckx, Roel; Wallace, Hilary; van Rooijen, Nils; Goethem, Thomas; Bobbink, Roland; Dorland, Edu; Gaudnik, Cassandre; Alard, Didier; Corcket, Emmanuel; Muller, Serge; Dise, Nancy B; Dupré, Cecilia; Diekmann, Martin; Honnay, Olivier
2014-12-01
Nutrient pollution presents a serious threat to biodiversity conservation. In terrestrial ecosystems, the deleterious effects of nitrogen pollution are increasingly understood and several mitigating environmental policies have been developed. Compared to nitrogen, the effects of increased phosphorus have received far less attention, although some studies have indicated that phosphorus pollution may be detrimental for biodiversity as well. On the basis of a dataset covering 501 grassland plots throughout Europe, we demonstrate that, independent of the level of atmospheric nitrogen deposition and soil acidity, plant species richness was consistently negatively related to soil phosphorus. We also identified thresholds in soil phosphorus above which biodiversity appears to remain at a constant low level. Our results indicate that nutrient management policies biased toward reducing nitrogen pollution will fail to preserve biodiversity. As soil phosphorus is known to be extremely persistent and we found no evidence for a critical threshold below which no environmental harm is expected, we suggest that agro-environmental schemes should include grasslands that are permanently free from phosphorus fertilization. © 2014 John Wiley & Sons Ltd.
13. Recovery of phosphorus from sewerage treatment sludge
Energy Technology Data Exchange (ETDEWEB)
Manuilova, Anastasia
1999-07-01
This thesis is a review of the current state of technologies for the removal of phosphorus from wastewater and sludge, and the recovery and re-use of phosphorus. It explains the need for phosphorus removal and describes the current removal processes. Focus is given to phosphorus crystallisation processes and to the processes which treat sewage treatment sludges into potential sources of phosphorus. An interesting possibility to recover phosphorus from sewage sludge by use of Psenner fractionation is also discussed. By this method, the following phosphate fractions of technological significance may be distinguished: (1) redox sensitive phosphates, mainly bound to Fe(OH){sub 3}; (2) phosphate adsorbed to surfaces (Al{sub 2}O{sub 3}), exchangeable against OH{sup -}, and alkali-soluble phosphate; (3) phosphate bound to CaCO{sub 3}, MgCO{sub 3} and in apatite; and (4) organically bound phosphate. The basic removal mechanisms, process schemes and treatment results are described. Two experiments with three different types of sludges from Henriksdal wastewater treatment plant in Stockholm were performed in the laboratory. It was shown that the addition of sodium hydroxide or hydrochloric acid cause the significant release of phosphate (about 80%) for all types of sludges. If a whole Psenner fractionation was performed the phosphate release is approximately 100%.
14. Phosphorus speciation by coupled HPLC-ICPMS: low level determination of reduced phosphorus in natural materials
Science.gov (United States)
Atlas, Zachary; Pasek, Matthew; Sampson, Jacqueline
2015-04-01
Phosphorus is a geologically important minor element in the Earth's crust commonly found as relatively insoluble apatite. This constraint causes phosphorus to be a key limiting nutrient in biologic processes. Despite this, phosphorus plays a direct role in the formation of DNA, RNA and other cellular materials. Recent works suggest that since reduced phosphorus is considerably more soluble than oxidized phosphorus that it was integrally involved in the development of life on the early Earth and may continue to play a role in biologic productivity to this day. This work examines a new method for quantification and identification of reduced phosphorus as well as applications to the speciation of organo-phosphates separated by coupled HPLC - ICP-MS. We show that reduced phosphorus species (P1+, P3+ and P5+) are cleanly separated in the HPLC and coupled with the ICPMS reaction cell, using oxygen as a reaction gas to effectively convert elemental P to P-O. Analysis at M/Z= 47 producing lower background and flatter baseline chromatography than analyses performed at M/Z = 31. Results suggest very low detection limits (0.05 μM) for P species analyzed as P-O. Additionally we show that this technique has potential to speciate at least 5 other forms of phosphorus compounds. We verified the efficacy of method on numerous materials including leached Archean rocks, suburban retention pond waters, blood and urine samples and most samples show small but detectible levels of reduced phosphorus and or organo-phaospates. This finding in nearly all substances analyzed supports the assumption that the redox processing of phosphorus has played a significant role throughout the history of the Earth and it's presence in the present environment is nearly ubiquitous with the reduced oxidation state phosphorus compounds, phosphite and hypophosphite, potentially acting as significant constituents in the anaerobic environment.
15. Electron-hole balance and the anomalous pressure-dependent superconductivity in black phosphorus
Science.gov (United States)
Guo, Jing; Wang, Honghong; von Rohr, Fabian; Yi, Wei; Zhou, Yazhou; Wang, Zhe; Cai, Shu; Zhang, Shan; Li, Xiaodong; Li, Yanchun; Liu, Jing; Yang, Ke; Li, Aiguo; Jiang, Sheng; Wu, Qi; Xiang, Tao; Cava, Robert J.; Sun, Liling
2017-12-01
Here we report the in situ high-pressure (up to ˜50 -GPa) Hall-effect measurements on single-crystal black phosphorus. We find a strong correlation between the sign of the Hall coefficient, an indicator of the dominant carrier type, and the superconducting transition temperature (TC). Importantly, we find a change from electron-dominant to hole-dominant carriers in the simple cubic phase of phosphorus at a pressure of ˜17.2 GPa, providing an explanation for the puzzling valley it displays in its superconducting TC vs pressure phase diagram. Our results reveal that hole carriers play an important role in developing superconductivity in elemental phosphorus and the valley in TC at 18.8 GPa is associated with a Lifshitz transition.
16. Removal of organic pollutants by surfactant modified zeolite: Comparison between ionizable phenolic compounds and non-ionizable organic compounds
Energy Technology Data Exchange (ETDEWEB)
Xie, Jie; Meng, Wenna [School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Rd., Shanghai 200240 (China); Wu, Deyi, E-mail: [email protected] [School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Rd., Shanghai 200240 (China); Zhang, Zhenjia; Kong, Hainan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Rd., Shanghai 200240 (China)
2012-09-15
by modified zeolite. Based on the different adsorption behavior, the uptake of non-ionizable pollutants was thought to be a single partitioning process into the surfactant bilayer. For ionizable compounds, however, interaction of the phenol group(s) with the positively charged 'head' of surfactant additionally functions.
17. Divergence analysis of atomic ionization processes and isoelectronic series
International Nuclear Information System (INIS)
Lopez-Rosa, S.; Angulo, J. C.; Antolin, J.; Esquivel, R. O.
2009-01-01
Fisher divergences (FDs) and Jensen-Shannon divergences (JSDs) are used in this work to quantify the informational discrepancies between the one-particle electron densities of neutral atoms, singly charged ions, and isoelectronic series. These dissimilarity magnitudes, computed for a set of 319 atomic systems in both position and momentum spaces, provide relevant information concerning pattern, structure, and periodicity properties of the ionization processes. In particular an apparent correlation between extremal values of the atomic ionization potential and the divergences is found. Results are compared with those obtained by quantum similarity techniques.
18. Many-electron phenomena in the ionization of ions
International Nuclear Information System (INIS)
Mueller, A.
2004-01-01
Full text: Single and multiple ionization in ion-atom collisions involve a multitude of complex interactions between the electrons and nuclei of projectile and target. Some of the complexity is avoided in studies of fast collisions when the impulse approximation can be applied and the electrons can be described as independent quasi-free particles with a known momentum distribution. For the detailed investigation of ionization mechanisms that can occur in fast ion-atom collisions, it is illuminating to consider collisions of ions (or atoms) and really free electrons with a narrow energy spread. High energy resolution in electron-ion collision studies provides access to individual, possibly even state-selective, reaction pathways. Even in the simple electron-ion collision system (simple compared with the initial ion-atom problem) single and multiple ionization still involve a multitude of complex mechanisms. Besides the direct removal of one or several electrons from the target by electron impact, resonant and non-resonant formation of intermediate multiply excited states which subsequently decay by electron emission is important in single and multiple ionization of ions and atoms. Direct ionization proceeds via one-step or multi-step knock-off mechanisms which can partly be disentangled by studying effects of different projectile species. The role of multiply excited states in the ionization can be experimentally studied in great detail by a further reduction of the initial ion-atom problem. Multiply excited states of atoms and ions can be selectively populated by photon-ion interactions making use of the potential for extreme energy resolution made available at modern synchrotron radiation sources. In the review talk, examples of studies on single and multiple ionization in electron-ion collisions will be discussed in some detail. Electron-ion collision experiments will also be compared with photon-ion interaction studies. Many-electron phenomena have been observed
19. Resonance ionization scheme development for europium
CERN Document Server
Chrysalidis, K; Fedosseev, V N; Marsh, B A; Naubereit, P; Rothe, S; Seiffert, C; Kron, T; Wendt, K
2017-01-01
Odd-parity autoionizing states of europium have been investigated by resonance ionization spectroscopy via two-step, two-resonance excitations. The aim of this work was to establish ionization schemes specifically suited for europium ion beam production using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). 13 new RILIS-compatible ionization schemes are proposed. The scheme development was the first application of the Photo Ionization Spectroscopy Apparatus (PISA) which has recently been integrated into the RILIS setup.
20. Increased ionization rate in laser enrichment
International Nuclear Information System (INIS)
Janes, G.S.; Pike, G.T.
1977-01-01
A system employing multiple, upper excitation levels in a technique for isotopically selective ionization to improve the ionization efficiency is described. Laser radiation is employed to excite particles with isotopic selectivity. Excitation is produced to a plurality of excited states below the ionization level with the result of increasing the number of available excited particles for ionization and thereby increasing the ionization cross section for improved system efficiency
1. Resonance ionization scheme development for europium
Energy Technology Data Exchange (ETDEWEB)
Chrysalidis, K., E-mail: [email protected]; Goodacre, T. Day; Fedosseev, V. N.; Marsh, B. A. [CERN (Switzerland); Naubereit, P. [Johannes Gutenberg-Universität, Institiut für Physik (Germany); Rothe, S.; Seiffert, C. [CERN (Switzerland); Kron, T.; Wendt, K. [Johannes Gutenberg-Universität, Institiut für Physik (Germany)
2017-11-15
Odd-parity autoionizing states of europium have been investigated by resonance ionization spectroscopy via two-step, two-resonance excitations. The aim of this work was to establish ionization schemes specifically suited for europium ion beam production using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). 13 new RILIS-compatible ionization schemes are proposed. The scheme development was the first application of the Photo Ionization Spectroscopy Apparatus (PISA) which has recently been integrated into the RILIS setup.
2. Estimate of dietary phosphorus intake using 24-h urine collection
Science.gov (United States)
Morimoto, Yuuka; Sakuma, Masae; Ohta, Hiroyuki; Suzuki, Akitsu; Matsushita, Asami; Umeda, Minako; Ishikawa, Makoto; Taketani, Yutaka; Takeda, Eiji; Arai, Hidekazu
2014-01-01
Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two healthy subjects were recruited for this study. Subjects collected urine samples over 24 h and weighed dietary records. We calculated dietary protein intake and phosphorus intake from dietary records and urine collection, and investigated associations between the two methods in estimating protein and phosphorus intake. Significant positive correlations were observed between dietary records and UC for protein and phosphorus intake. The average intakes determined from dietary records were significantly higher than from urine collection for both protein and phosphorus. There was a significant positive correlation between both the phosphorus and protein difference in dietary records and urine collection. The phosphorus-protein ratio in urine collection was significantly higher than in dietary records. Our data indicated that the 24-h urine collection method can estimate the amount of dietary phosphorus intake, and the results were superior to estimation by weighed dietary record. PMID:25120281
3. Estimate of dietary phosphorus intake using 24-h urine collection.
Science.gov (United States)
Morimoto, Yuuka; Sakuma, Masae; Ohta, Hiroyuki; Suzuki, Akitsu; Matsushita, Asami; Umeda, Minako; Ishikawa, Makoto; Taketani, Yutaka; Takeda, Eiji; Arai, Hidekazu
2014-07-01
Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two healthy subjects were recruited for this study. Subjects collected urine samples over 24 h and weighed dietary records. We calculated dietary protein intake and phosphorus intake from dietary records and urine collection, and investigated associations between the two methods in estimating protein and phosphorus intake. Significant positive correlations were observed between dietary records and UC for protein and phosphorus intake. The average intakes determined from dietary records were significantly higher than from urine collection for both protein and phosphorus. There was a significant positive correlation between both the phosphorus and protein difference in dietary records and urine collection. The phosphorus-protein ratio in urine collection was significantly higher than in dietary records. Our data indicated that the 24-h urine collection method can estimate the amount of dietary phosphorus intake, and the results were superior to estimation by weighed dietary record.
4. Total Value of Phosphorus Recovery.
Science.gov (United States)
Mayer, Brooke K; Baker, Lawrence A; Boyer, Treavor H; Drechsel, Pay; Gifford, Mac; Hanjra, Munir A; Parameswaran, Prathap; Stoltzfus, Jared; Westerhoff, Paul; Rittmann, Bruce E
2016-07-05
Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.
5. Ambient ionization mass spectrometry: A tutorial
Energy Technology Data Exchange (ETDEWEB)
Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Shiea, Jentaie, E-mail: [email protected] [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University, Kaohsiung, Taiwan (China)
2011-09-19
Highlights: {yields} Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. {yields} We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. {yields} The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.
6. Ambient ionization mass spectrometry: A tutorial
International Nuclear Information System (INIS)
Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu; Shiea, Jentaie
2011-01-01
Highlights: → Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. → We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. → The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.
7. PHOSPHORUS METABOLISM AND ESTIMATION OF PHOSPHORUS REQUIREMENTS FOR SHEEP
Directory of Open Access Journals (Sweden)
H LOUVANDINI
1996-01-01
8. Soil phosphorus availability and soybean response to phosphorus starter fertilizer
Directory of Open Access Journals (Sweden)
Ciro Antonio Rosolem
2014-10-01
Full Text Available Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis. No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.
9. Health effects of ionizing radiation
International Nuclear Information System (INIS)
Pathak, B.
1989-12-01
10. Display of charged ionizing particles
International Nuclear Information System (INIS)
Cano S, D.; Ortiz A, M. D.; Amarillas S, L. E.; Vega C, H. R.
2017-10-01
The human being is exposed to sources of ionizing and non-ionizing radiation, both of natural or anthropogenic origin. None of these, except non-ionizing such as visible light and infrared radiation, can be detected by the sense of sight and touch respectively. The sun emits charged particles with speeds close to the light that interact with the atoms of the gases present in the atmosphere, producing nuclear reactions that in turn produce other particles that reach the surface of the Earth and reach the living beings. On Earth there are natural radioisotopes that, when they disintegrate, emit ionizing radiation that contributes to the dose we receive. A very old system that allows the visualization of the trajectories of the charged ionizing particles is the Fog Chamber that uses a saturated steam that when crossed by particles with mass and charge, as alpha and beta particles produce condensation centers along its path leaves a trace that can be seen. The objective of this work was to build a fog chamber using easily accessible materials. To measure the functioning of the fog chamber, cosmic rays were measured, as well as a source of natural metal uranium. The fog chamber allowed seeing the presence of traces in alcohol vapor that are produced in a random way. Introducing the uranium foil inside the fog chamber, traces of alpha particles whose energy varies from 4 to 5 MeV were observed. (Author)
11. Ionization equilibrium in dense plasmas
International Nuclear Information System (INIS)
Ying, R.
1987-01-01
The average degree of ionization for a strongly coupled plasma is investigated and calculated. Two widely used approaches: the Saha equation method and the Thomas-Fermi (TF) statistical atomic model are adopted to determine the degree of ionization. Both methods are modified in a number of ways to include the strong-coupling effect in the plasma. In the Saha equation approach, the strong-coupling effects are introduced through: (i) a replacement of the Coulomb potential by a screened Debye potential; (ii) adoption of the Planck-Larkin partition function; (iii) description of the electron component by Fermi-Dirac statistics. The calculated degree of ionization exceeds that obtained from the original Saha equation, exhibits a minimum as a function of the density and shows an abrupt phase transition from weakly ionized to a fully ionized state. The zero-temperature TF model for compressed ions and the finite-temperature TF model for ions are investigated for the first time. In order to take into account the strong-coupling effect in a systematic way, a strong-coupling TF model is set up. Favorable results with the relatively simple approximations indicate that the newly established strong-coupling TF model is a more systematic and physically consistent approach
12. Multiple chamber ionization detector
International Nuclear Information System (INIS)
Solomon, E.E.
1980-01-01
A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)
13. Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char
Science.gov (United States)
Tang, Huiqing; Qi, Tengfei; Qin, Yanqi
2015-09-01
In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore-char briquette reached a metallization degree of 80-82% and a residual carbon content of 0.1-0.3 mass%. Under the optimized condition, phosphorus remained in the gangue as calcium phosphate. In the melting separation stage, phosphorus content ([%P]) in molten iron could be controlled by introducing a Na2CO3 additive, and the phosphorus behavior could be predicted using ion molecular coexistence theory. Molten iron with [%P] less than 0.3 mass% was obtained from the metallic briquettes with the aforementioned quality by introducing 2-4% Na2CO3 and the iron recovery rate was 75-78%.
14. Progress of laser ionization mass spectrometry for elemental analysis - A review of the past decade
International Nuclear Information System (INIS)
Lin Yiming; Yu Quan; Hang Wei; Huang Benli
2010-01-01
Mass spectrometry using a laser ionization source has played a significant role in elemental analysis. Three types of techniques are widely used: high irradiance laser ionization mass spectrometry is capable of rapid determination of elements in solids; single particle mass spectrometry is a powerful tool for single particle characterization; and resonance ionization mass spectrometry is applied for isotope ratio measurements with high sensitivity and selectivity. In this review, the main features of the laser ablation process and plasma characterization by mass spectrometry are summarized. Applications of these three techniques for elemental analysis are discussed.
15. Double electron ionization in Compton scattering of high energy photons by helium atoms
Energy Technology Data Exchange (ETDEWEB)
Amusia, M.Y.; Mikhailov, A.I. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation)
1995-08-01
The cross section for double-electron ionization of two-electron atoms and ions in Compton scattering of high energy photons is calculated. It is demonstrated that its dependence on the incoming photon frequency is the same as that for single-electron ionization. The ratio of {open_quotes}double-to-single{close_quotes} ionization in Compton scattering was found to be energy independent and almost identical with the corresponding value for photoionization. For the He atom it is 1.68%. This surprising result deserves experimental verification.
16. RESIDUAL-GAS-IONIZATION BEAM PROFILE MONITORS IN RHIC.
Energy Technology Data Exchange (ETDEWEB)
CONNOLLY, R.; MICHNOFF, R.; TEPIKIAN, S.
2005-05-16
Four ionization profile monitors (IPMs) in RHIC measure vertical and horizontal beam profiles in the two rings by measuring the distribution of electrons produced by beam ionization of residual gas. During the last three years both the collection accuracy and signal/noise ratio have been improved. An electron source is mounted across the beam pipe from the collector to monitor microchannel plate (MCP) aging and the signal electrons are gated to reduce MCP aging and to allow charge replenishment between single-turn measurements. Software changes permit simultaneous measurements of any number of individual bunches in the ring. This has been used to measure emittance growth rates on six bunches of varying intensities in a single store. Also the software supports FFT analysis of turn-by-turn profiles of a single bunch at injection to detect dipole and quadrupole oscillations.
17. Multiple ionization of C 60 in collisions with 2.33 MeV/u O-ions and giant plasmon excitation
Science.gov (United States)
Kelkar, A. H.; Kadhane, U.; Misra, D.; Kumar, Ajay; Tribedi, L. C.
2007-03-01
Single and multiple ionization of C60 in collisions with fast (v = 9.7 a.u.) Oq+ ions have been studied. Relative cross sections for production of C 601+ to C 604+ have been measured. The intensity ratios of double-to-single ionization agree very well with a model based on giant dipole plasmon resonance (GDPR). Almost linear increasing trend of the yields of single and double ionizations with projectile charge state is well reproduced by the single and double plasmon excitation mechanisms. The observed charge state independence of triple and quadruple ionization is in sharp contrast to the GDPR model.
18. Multiple ionization of C60 in collisions with 2.33MeV/u O-ions and giant plasmon excitation
International Nuclear Information System (INIS)
Kelkar, A.H.; Kadhane, U.; Misra, D.; Kumar, Ajay; Tribedi, L.C.
2007-01-01
Single and multiple ionization of C 60 in collisions with fast (v=9.7a.u.) O q+ ions have been studied. Relative cross sections for production of C 60 1+ to C 60 4+ have been measured. The intensity ratios of double-to-single ionization agree very well with a model based on giant dipole plasmon resonance (GDPR). Almost linear increasing trend of the yields of single and double ionizations with projectile charge state is well reproduced by the single and double plasmon excitation mechanisms. The observed charge state independence of triple and quadruple ionization is in sharp contrast to the GDPR model
19. Spectroscopy of highly ionized atoms
International Nuclear Information System (INIS)
Livingston, A.E.
1987-01-01
The atomic structure and decay characteristics of excited states in multiply ionized atoms represent a fertile testing ground for atomic calculations ranging from accurate ab initio theory for few-electron systems to practical semi-empirical approaches for many-electron species. Excitation of fast ions by thin foils generally produces the highest ionization stages for heavy ions in laboratory sources. The associated characteristics of spectroscopic purity and high time resolution provide unique capabilities for studying the atomic properties of highly-ionized atoms. This report is limited to a brief discussion of three classes of atomic systems that are experiencing current theoretical and experimental interest: precision structure of helium-like ions, fine structure of doubly-excited states, and lifetimes of metastable states. Specific measurements in each of these types of systems are mentioned, with emphasis on the relation to studies involving slow, highly-charged ions
20. Ionization detectors in environmental analysis
International Nuclear Information System (INIS)
Leonhardt, J.W.
1982-01-01
Ionization detectors (IDs) use the information contained in the radiation-produced ionization current regarding the chemical composition of gas mixtures. The radionuclide radiation sources, 3 H, 55 Fe, 63 Ni, 85 Kr, 90 Sr, 241 Am, are used to produce carriers. Using recombination effects and carrier multiplication by electrical fields the response of IDs can be improved. There are electron capture detectors, cross-section detectors and noble-gas detectors, mainly used in gas chromatographic devices, and continuously working aerosol ionization detectors. Halocarbons, metal chelates, metal organic and inorganic compounds, pesticides, herbicides, insecticides, but also SO 2 , AsH 3 , ClCN, HCN, HF, NH 3 , CO, CO 2 , H 2 O, can be determined within the pp10 9 range. They are used in automatic systems to control air pollution around industrial plants, in hospitals and factories, but also to prevent high levels of pesticides in agriculture products. (author)
1. Ionization of nitrogen cluster beam
International Nuclear Information System (INIS)
Yano, Katsuki; Be, S.H.; Enjoji, Hiroshi; Okamoto, Kosuke
1975-01-01
A nitrogen cluster beam (neutral particle intensity of 28.6 mAsub(eq)) is ionized by electron collisions in a Bayard-Alpert gauge type ionizer. The extraction efficiency of about 65% is obtained at an electron current of 10 mA with an energy of 50 eV. The mean cluster size produced at a pressure of 663 Torr and temperature of 77.3 K is 2x10 5 molecules per cluster. By the Coulomb repulsion force, multiply ionized cluster ions are broken up into smaller fragments and the cluster ion size reduces to one-fourth at an electron current of 15 mA. Mean neutral cluster sizes depend strongly on the initial degree of saturation PHI 0 and are 2x10 5 , 7x10 4 and 3x10 4 molecules per cluster at PHI 0 's of 0.87, 0.66 and 0.39, respectively. (auth.)
2. Lithium atoms on helium nanodroplets: Rydberg series and ionization dynamics
Science.gov (United States)
Lackner, Florian; Krois, Günter; Ernst, Wolfgang E.
2017-11-01
The electronic excitation spectrum of lithium atoms residing on the surface of helium nanodroplets is presented and analyzed employing a Rydberg-Ritz approach. Utilizing resonant two-photon ionization spectroscopy, two different Rydberg series have been identified: one assigned to the nS(Σ) series and the other with predominantly nP(Π) character. For high Rydberg states, which have been resolved up to n = 13, the surrounding helium effectively screens the valence electron from the Li ion core, as indicated by the apparent red-shift of Li transitions and lowered quantum defects on the droplet with respect to their free atom counterparts. For low n states, the screening effect is weakened and the prevailing repulsive interaction gives rise to strongly broadened and blue-shifted transitions. The red-shifts originate from the polarization of nearby He atoms by the positive Li ion core. As a consequence of this effect, the ionization threshold is lowered by 116 ± 10 cm-1 for Li on helium droplets with a radius of about 40 Å. Upon single-photon ionization, heavy complexes corresponding to Li ions attached to intact helium droplets are detected. We conclude that ionization close to the on-droplet ionization threshold triggers a dynamic process in which the Li ion core undergoes a transition from a surface site into the droplet.
3. Phosphorus nutrition of mycorrhizal trees.
Science.gov (United States)
Plassard, C; Dell, B
2010-09-01
Globally, phosphorus (P) limits productivity of trees in many forests and plantations especially in highly weathered, acidic or calcareous profiles. Most trees form mycorrhizal associations which are prevalent in the organic and mineral soil horizons. This review critically examines mechanisms that enhance the acquisition of P by tree roots. Mycorrhizal roots have a greater capacity to take up phosphate (Pi) from the soil solution than non-mycorrhizal root tips. Factors that contribute to this include the extent of extraradical hyphal penetration of soil and the physiology and biochemistry of the fungal/soil and fungal/plant interfaces. Ectomycorrhizal (ECM) trees are likely to benefit from association with basidiomycetes that possess several high-affinity Pi transporters that are expressed in extraradical hyphae and whose expression is enhanced by P deficiency. To understand fully the role of these putative transporters in the symbiosis, data regarding their localization, Pi transport capacities and regulation are required. Some ECM fungi are able to effect release of Pi from insoluble mineral P through excretion of low-molecular-weight organic anions such as oxalate, but the relative contribution of insoluble P dissolution in situ remains to be quantified. How the production of oxalate is regulated by nitrogen remains a key question to be answered. Lastly, phosphatase release from mycorrhizas is likely to play a significant role in the acquisition of Pi from labile organic forms of P (Po). As labile forms of Po can constitute the major fraction of the total P in some tropical and temperate soils, a greater understanding of the forms of Po available to the phosphatases is warranted.
4. The dosimetry of ionizing radiation
CERN Document Server
Bjaerngard, Bengt E; Kase, Kenneth R
1987-01-01
The Dosimetry of Ionizing Radiation, Volume II, attempts to fill the need for updated reference material on the field of radiation dosimetry. This book presents some broad topics in dosimetry and a variety of radiation dosimetry instrumentation and its application. The book opens with a chapter that extends and applies the concepts of microdosimetry to biological systems. This is followed by separate chapters on the state- of-the-art equipment and techniques used to determine neutron spectra; studies to determine recombination effects in ionization chambers exposed to high-intensity pulsed ra
5. Ionization chambers for LET determination
DEFF Research Database (Denmark)
Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki
2010-01-01
resolution and high sensitivity are necessary. For exact dosimetry which is done using ionization chambers (ICs), the recombination taking place in the IC has to be known. Up to now, recombination is corrected phenomenologically and more practical approaches are currently used. Nevertheless, Jaff´e's theory...... of columnar recombination was designed to model the detector efficiency of an ionization chamber. Here, we have shown that despite the approximations and simplification made, the theory is correct for the LETs typically found in clinical radiotherapy employing particles from protons to carbon ions...
6. Prenatal exposition on ionizing radiations
International Nuclear Information System (INIS)
2001-01-01
The Sessions on Prenatal Exposition on Ionizing Radiations was organized by the Argentine Radioprotection Society, in Buenos Aires, between 8 and 9, November 2001. In this event, were presented papers on: biological effects of ionizing radiation; the radiation protection and the pregnant woman; embryo fetal development and its relationship with the responsiveness to teratogens; radioinduced delayed mental; neonatal irradiation: neurotoxicity and modulation of pharmacological response; pre implanted mouse embryos as a model of uranium toxicity studies; hereditary effects of the radiation and new advances from the UNSCEAR 2001; doses estimation in embryo
7. Secondary poisoning of kestrels by white phosphorus
Science.gov (United States)
Sparling, D.W.; Federoff, N.E.
1997-01-01
Since 1982, extensive waterfowl mortality due to white phosphorus (P4) has been observed at Eagle River Flats, a tidal marsh near Anchorage, Alaska. Ducks and swans that ingest P4 pellets become lethargic and may display severe convulsions. Intoxicated waterfowl attract raptors and gulls that feed on dead or dying birds. To determine if avian predators can be affected by secondary poisoning, we fed American kestrels (Falco sparverius) 10-day-old domestic chickens that had been dosed with white phosphorus. Eight of 15 kestrels fed intact chicks with a pellet of P4 implanted in their crops died within seven days. Three of 15 kestrels fed chicks that had their upper digestive tracts removed to eliminate any pellets of white phosphorus also died. Hematocrit and hemoglobin in kestrels decreased whereas lactate dehydrogenaseL, glucose, and alanine aminotransferase levels in plasma increased with exposure to contaminated chicks. Histological examination of liver and kidneys showed that the incidence and severity of lesions increased when kestrels were fed contaminated chicks. White phosphorus residues were measurable in 87% of the kestrels dying on study and 20% of the survivors. This study shows that raptors can become intoxicated either by ingesting portions of digestive tracts containing white phosphorus pellets or by consuming tissues of P4 contaminated prey.
8. The Adequacy of Phosphorus Binder Prescriptions Among American Hemodialysis Patients
Science.gov (United States)
Huml, Anne M.; Sullivan, Catherine M.; Leon, Janeen B.; Sehgal, Ashwini R.
2013-01-01
Because hemodialysis treatment has a limited ability to remove phosphorus, dialysis patients must restrict dietary phosphorus intake and use phosphorus binding medication. Among patients with restricted dietary phosphorus intake (1000 mg/d), phosphorus binders must bind about 250 mg of excess phosphorus per day and among patients with more typical phosphorus intake (1500 mg/d), binders must bind about 750 mg per day. To determine the phosphorus binding capacity of binder prescriptions among American hemodialysis patients, we undertook a cross-sectional study of a random sample of in-center chronic hemodialysis patients. We obtained data for one randomly selected patient from 244 facilities nationwide. About one-third of patients had hyperphosphatemia (serum phosphorus level > 5.5 mg/dL). Among the 224 patients prescribed binders, the mean phosphorus binding capacity was 256 mg/d (SD 143). 59% of prescriptions had insufficient binding capacity for restricted dietary phosphorus intake, and 100% had insufficient binding capacity for typical dietary phosphorus intake. Patients using two binders had a higher binding capacity than patients using one binder (451 vs. 236 mg/d, p phosphorus balance. Use of two binders results in higher binder capacity. Further work is needed to understand the impact of binder prescriptions on mineral balance and metabolism and to determine the value of substantially increasing binder prescriptions. PMID:23013171
9. Kinetics of a plasma streamer ionization front
Science.gov (United States)
Taccogna, Francesco; Pellegrini, Fabrizio
2018-02-01
A streamer is a non-linear and non-local gas breakdown mode. Its large-scale coherent structures, such as the ionization front, are the final results of a hierarchical cascade starting from the single particle dynamics. Therefore, this phenomenon covers, by definition, different space and time scales. In this study, we have reproduced the ionization front formation and development by means of a particle-based numerical methodology. The physical system investigated concerns of a high-voltage ns-pulsed surface dielectric barrier discharge. Different reduced electric field regimes ranging from 50 to 500 Td have been considered for two gases: pure atomic Ar and molecular N2. Results have shown the detailed structure of the negative streamer: the leading edge, the head, the interior and the tail. Its dynamical evolution and the front propagation velocity have been calculated for the different cases. Finally, the deviation of the electron energy distribution function from equilibrium behavior has been pointed out as a result of a fast and very localized phenomenon.
10. Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil
Directory of Open Access Journals (Sweden)
H. SOINNE
2008-12-01
Full Text Available The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc and water extractable total P (TPw, and molybdate reactive P (MRPw. Urine additions immediately increased soil pH and MRPw, but no such response was observed in PAc extraction due to the low pH (4.65 of the extractant enhancing the resorption of P. The PAc responded to the dunginduced increase in soil total P similarly as did Pw, which suggests that both tests can serve to detect areas of high P concentration. However, water extraction was a more sensitive method for estimating short-term changes in P solubility. In pasture soils, the risk of P loss increases as a result of the interaction of urination and high P concentration in the topsoil resulting from continuous dung excretion.;
11. Electronic structure and spectroscopy of nucleic acid bases: Ionization energies, ionization-induced structural changes, and photoelectron spectra
Energy Technology Data Exchange (ETDEWEB)
Bravaya, Ksenia B.; Kostko, Oleg; Dolgikh, Stanislav; Landau, Arie; Ahmed, Musahid; Krylov, Anna I.
2010-08-02
We report high-level ab initio calculations and single-photon ionization mass spectrometry study of ionization of adenine (A), thymine (T), cytosine (C) and guanine (G). For thymine and adenine, only the lowest-energy tautomers were considered, whereas for cytosine and guanine we characterized five lowest-energy tautomeric forms. The first adiabatic and several vertical ionization energies were computed using equation-of-motion coupled-cluster method for ionization potentials with single and double substitutions. Equilibrium structures of the cationic ground states were characterized by DFT with the {omega}B97X-D functional. The ionization-induced geometry changes of the bases are consistent with the shapes of the corresponding molecular orbitals. For the lowest-energy tautomers, the magnitude of the structural relaxation decreases in the following series G > C > A > T, the respective relaxation energies being 0.41, 0.32, 0.25 and 0.20 eV. The computed adiabatic ionization energies (8.13, 8.89, 8.51-8.67 and 7.75-7.87 eV for A,T,C and G, respectively) agree well with the onsets of the photoionization efficiency (PIE) curves (8.20 {+-} 0.05, 8.95 {+-} 0.05, 8.60 {+-} 0.05 and 7.75 {+-} 0.05 eV). Vibrational progressions for the S{sub 0}-D{sub 0} vibronic bands computed within double-harmonic approximation with Duschinsky rotations are compared with previously reported experimental photoelectron spectra.
12. Thermophysics Characterization of Multiply Ionized Air Plasma Absorption of Laser Radiation
Science.gov (United States)
Wang, Ten-See; Rhodes, Robert; Turner, Jim (Technical Monitor)
2002-01-01
The impact of multiple ionization of air plasma on the inverse Bremsstrahlung absorption of laser radiation is investigated for air breathing laser propulsion. Thermochemical properties of multiply ionized air plasma species are computed for temperatures up to 200,000 deg K, using hydrogenic approximation of the electronic partition function; And those for neutral air molecules are also updated for temperatures up to 50,000 deg K, using available literature data. Three formulas for absorption are calculated and a general formula is recommended for multiple ionization absorption calculation. The plasma composition required for absorption calculation is obtained by increasing the degree of ionization sequentially, up to quadruple ionization, with a series of thermal equilibrium computations. The calculated second ionization absorption coefficient agrees reasonably well with that of available data. The importance of multiple ionization modeling is demonstrated with the finding that area under the quadruple ionization curve of absorption is found to be twice that of single ionization. The effort of this work is beneficial to the computational plasma aerodynamics modeling of laser lightcraft performance.
13. Effect of dietary supplementation of inorganic phosphorus on feed ...
African Journals Online (AJOL)
Effect of dietary supplementation of inorganic phosphorus on feed intake, protein intake, feed conversation and phosphorus gain/loss of the hybrid African catfish Heterobranchus bidorsalis X Clarias gariepinus fry.
14. Global Fertilizer and Manure, Version 1: Phosphorus in Manure Production
Data.gov (United States)
National Aeronautics and Space Administration — The Phosphorus in Manure Production dataset of the Global Fertilizer and Manure, Version 1 Data Collection represents the amount of phosphorus manure produced and...
15. Reaching ultra low phosphorus concentrations by filtration techniques
OpenAIRE
Scherrenberg, S.M.
2011-01-01
This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (
16. Phosphorus cycling in agricultural soils. Pt.1: Introduction
NARCIS (Netherlands)
Ritsema, C.J.
1987-01-01
The excess of phosphorus brought into the soil system is subject to transformation processes and displacement. In general, the mobility of phosphorus in soil solution will remain low due to the very effective retention possibilities of soil
17. Flammability of Epoxy Resins Containing Phosphorus
Science.gov (United States)
Hergenrother, P. M.; Thompson, C. M.; Smith, J. G.; Connell, J. W.; Hinkley, J. A.
2005-01-01
As part of a program to develop fire-resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame-retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.
18. Determination of photoionization cross-sections of different organic molecules using gas chromatography coupled to single-photon ionization (SPI) time-of-flight mass spectrometry (TOF-MS) with an electron-beam-pumped rare gas excimer light source (EBEL): influence of molecular structure and analytical implications.
Science.gov (United States)
Eschner, Markus S; Zimmermann, Ralf
2011-07-01
This work describes a fast and reliable method for determination of photoionization cross-sections (PICS) by means of gas chromatography (GC) coupled to single-photon ionization mass spectrometry (SPI-MS). Photoionization efficiency (PIE) data for 69 substances was obtained at a photon energy of 9.8 ± 0.4 eV using an innovative electron-beam-pumped rare gas excimer light source (EBEL) filled with argon. The investigated analytes comprise 12 alkylbenzenes as well as 11 other substituted benzenes, 23 n-alkanes, ten polyaromatic hydrocarbons, seven aromatic heterocycles, and six polyaromatic heterocycles. Absolute PICS for each substance at 9.8 eV are calculated from the relative photoionization efficiencies of the compounds with respect to benzene, whose photoionization cross-section data is well known. Furthermore, a direct correlation between the type of benzene substituents and their absolute PICS is presented and discussed in depth. Finally, comparison of previously measured photoionization cross-sections for 20 substances shows good agreement with the data of the present work.
19. Effect of phosphorus sources on phosphorus and nitrogen utilization by three sweet potato cultivars
International Nuclear Information System (INIS)
Montanez, A.; Zapata, F.; Kumarasinghe, K.S.
1996-01-01
A greenhouse experiment was conducted at the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf, Austria using three sweet potato cultivars, TIS 2, TIS 3053 and TIS 1487. The three sweet potato cultivars were grown at two levels of phosphorus (0 kg P/kg soil and 60 kg P/kg soil). The fertilizer treatments consisted of two sources of phosphorus, Gafza rock Phosphate and triple super phosphate with 14.19 and 19.76% total phosphorus, respectively. 15 N labelled urea was used to study the nitrogen recovery in tubers from the applied nitrogen fertilizer. The results from these preliminary studies indicate that there is considerable genotypic variation among cultivars in the efficiency with which phosphorus and nitrogen are taken up and used to produce biomass. Their response to different sources of phosphorus are also variable. TIS-2 and TIS-1487 have a greater ability to absorb phosphorus from Gafza rock phosphate and produce higher tube yields indicating their greater potential for using alternative sources of natural phosphate fertilizers more effectively. Gafza rock phosphate also increased accumulation of nitrogen in TIS-1487, a characteristic which will place this cultivar at an advantage when growing in soils low in nitrogen. On an overall basis taking into account tuber yield, phosphorus use efficiency, and nitrogen use efficiency, TIS-2 may be considered the better candidate for introduction into soils poor in resources particularly phosphorus. This study was conducted with a limited number of cultivars due to limitation in the availability of germplasma. In spite of this, the differences in their abilities for phosphorus and nitrogen uptake and use are clearly visible which justifies large scale screening experiments using a broader germplasm base, in the future. (author). 14 refs, 1 fig., 3 tabs
20. Ionizing radiation and genetic risks
International Nuclear Information System (INIS)
Sankaranarayanan, K.; Wassom, J.S.
2005-01-01
Recent estimates of genetic risks from exposure of human populations to ionizing radiation are those presented in the 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). These estimates incorporate two important concepts, namely, the following: (1) most radiation-induced mutations are DNA deletions, often encompassing multiple genes, but only a small proportion of the induced deletions is compatible with offspring viability; and (2) the viability-compatible deletions induced in germ cells are more likely to manifest themselves as multi-system developmental anomalies rather than as single gene disorders. This paper: (a) pursues these concepts further in the light of knowledge of mechanisms of origin of deletions and other rearrangements from two fields of contemporary research: repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and human molecular genetics; and (b) extends them to deletions induced in the germ cell stages of importance for radiation risk estimation, namely, stem cell spermatogonia in males and oocytes in females. DSB repair studies in somatic cells have elucidated the roles of two mechanistically distinct pathways, namely, homologous recombination repair (HRR) that utilizes extensive sequence homology and non-homologous end-joining (NHEJ) that requires little or no homology at the junctions. A third process, single-strand annealing (SSA), which utilizes short direct repeat sequences, is considered a variant of HRR. HRR is most efficient in late S and G 2 phases of the cell cycle and is a high fidelity mechanism. NHEJ operates in all cell cycle phases, but is especially important in G 1 . In the context of radiation-induced DSBs, NHEJ is error-prone. SSA is also an error-prone mechanism and its role is presumably similar to that of HRR. Studies in human molecular genetics have demonstrated that the occurrence of large deletions, duplications or other rearrangements
1. Biopositive Effects of Ionizing Radiation?
International Nuclear Information System (INIS)
Broda, E.
1972-01-01
This paper was written for a talk given by E. Broda in Vienna for an event organised by the chemical physical society, the Austrian biochemical society and the Austrian biophysical society in December 1972. In this paper Broda analyses the question of biopositive effects of ionizing radiation. (nowak)
2. Resonance ionization spectroscopy in dysprosium
Energy Technology Data Exchange (ETDEWEB)
Studer, D., E-mail: [email protected]; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Institut für Physik (Germany)
2017-11-15
We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6sns- and 6snd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm{sup −1}, which agrees with the current literature value of 47901.7(6) cm{sup −1}, but is one order of magnitude more precise.
3. Negative chemical ionization mass spectrometry
International Nuclear Information System (INIS)
Smit, A.L.C.
1979-01-01
This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)
4. Natural sources of ionizing radiations
International Nuclear Information System (INIS)
Marej, A.N.
1984-01-01
Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed
International Nuclear Information System (INIS)
Hrudkova, A.; Pohlova, M.; Sedlackova, J.
1974-01-01
Application possibilities are discussed of ionizing radiation in inhibiting plant germination, in radiopasteurization and radiosterilization of food. Also methods of combining radiation with thermal food sterilization are discussed. The problems of radiation doses and of hygienic purity of irradiated foodstuffs are dealt with. (B.S.)
6. Multiphoton ionization of atomic cesium
International Nuclear Information System (INIS)
Compton, R.N.; Klots, C.E.; Stockdale, J.A.D.; Cooper, C.D.
1984-01-01
We describe experimental studies of resonantly enhanced multi-photon ionization (MPI) of cesium atoms in the presence and absence of an external electric field. In the zero-field studies, photo-electron angular distributions for one- and two-photon resonantly enhanced MPI are compared with the theory of Tang and Lambropoulos. Deviations of experiment from theory are attributed to hyperfine coupling effects in the resonant intermediate state. The agreement between theory and experiment is excellent. In the absence of an external electric field, signal due to two-photon resonant three-photon ionization of cesium via np states is undetectable. Application of an electric field mixes nearby nd and ns levels, thereby inducing excitation and subsequent ionization. Signal due to two-photon excitation of ns levels in field-free experiments is weak due to their small photoionization cross section. An electric field mixes nearby np levels which again allows detectable photo-ionization signal. For both ns and np states the ''field induced'' MPI signal increases as the square of the electric field for a given principal quantum number and increases rapidly with n for a given field strength
7. On the Saha Ionization Equation
Abstract. We revisit the Saha Ionization Equation in order to highlightthe rich interdisciplinary content of the equation thatstraddles distinct areas of spectroscopy, thermodynamics andchemical reactions. In a self-contained discussion, relegatedto an appendix, we delve further into the hidden message ofthe equation in terms ...
8. Phosphorus-containing macrocyclic compounds: synthesis and properties
International Nuclear Information System (INIS)
Knyazeva, I R; Burilov, Alexander R; Pudovik, Michael A; Habicher, Wolf D
2013-01-01
Main trends in the development of methods for the synthesis of phosphorus-containing macrocyclic compounds in the past 15 years are considered. Emphasis is given to reactions producing macrocyclic structures with the participation of a phosphorus atom and other functional groups involved in organophosphorus molecules and to modifications of macrocycles by phosphorus compounds in different valence states. Possibilities of the practical application of phosphorus-containing macrocyclic compounds in difference areas of science and engineering are discussed. The bibliography includes 205 references.
9. Production of carrier-free phosphorus-33 at MURR
International Nuclear Information System (INIS)
Jia, W.; Ketring, A.R.; Schuh, J.; Lanigan, J.; Ma, D.; Manson, L.; Chanley, D.
1996-01-01
Phosphorus-33, a new radionuclide used in medical and biochemical research, is produced at the University of Missouri research reactor (MURR) in production quantities. Phosphorus-33 has a longer shelf life and lower dose rates than phosphorus-32. Recently, the MURR and New England Nuclear (NEN) jointly developed a method to recover carrier-free phosphorus-33 as well as the enriched sulfur target using a sublimation technique at reduced pressure
10. Determination of traces of phosphorus using isotope exchange
International Nuclear Information System (INIS)
Zeman, A.; Kratzer, K.
1976-01-01
A simple and selective radioanalytical method for the determination of phosphorus (0.015 - 5 μg in a 5 ml sample), based on the heterogeneous isotope exchange, has been developed. The sample containing phosphorus is shaken in the presence of molybdate with a standard solution of tetraphenylarsonium molybdophosphate labelled with phosphorus-32 in 1-2 dicloroethan. From the distribution of the activity between the aqueous and organic phases the amount of phosphorus in the sample can be determined. (Authors)
11. Domestic source of phosphorus to sewage treatment works.
OpenAIRE
Comber, S; Gardner, M; Georges, K; Blackwood, D; Gilmour, D
2013-01-01
Phosphorus is an element essential for life. Concerns regarding long-term security of supply and issues related to eutrophication of surface waters once released into the aquatic environment have led governments to consider and apply measures for reducing the use and discharge of phosphorus. Examples of source control include legislation to reduce phosphorus use in domestic detergents. This research shows that other domestic sources of phosphorus also contribute significantly to the domestic ...
12. [Bone and Nutrition. A novel function of phosphorus].
Science.gov (United States)
Taketani, Yutaka; Imi, Yukiko; Abuduli, Maerjianghan
2015-07-01
Phosphorus is an essential nutrient for bone formation by forming hydroxyapatite with calcium. Simultaneously, phosphorus is also a component of high energy bond of ATP, nucleic acids, and phospholipids. Recent studies have demonstrated that excess or lack of dietary phosphorus intake may cause vascular dysfunction, cardiac hypertrophy, and impaired glucose tolerance. Here, we introduce recent findings about the effects of high or low dietary phosphorus intake on several organs except for bone.
13. Phosphorus-doped bismuth telluride films by electrodeposition
Energy Technology Data Exchange (ETDEWEB)
Zhou, Jian, E-mail: [email protected] [Department of Materials Science and Engineering, College of Materials, Xiamen 361005 (China); Lin, Qinghan; Li, Hengyi [Department of Materials Science and Engineering, College of Materials, Xiamen 361005 (China); Cheng, Xuan [Department of Materials Science and Engineering, College of Materials, Xiamen 361005 (China); Fujian Key Laboratory of Advanced Materials, Xiamen University, Xiamen 361005 (China)
2013-08-15
Phosphorus-doped Bi{sub 2}Te{sub 3} films were synthesized on a stainless-steel electrode by electrochemical deposition. X-ray diffraction, scanning electron microscopy and transmission electron microscopy confirmed that the films are single-phased Bi{sub 2}Te{sub 3} solid solutions with a rhombohedral structure. The as-prepared films exhibit n-type characteristics with the Hall coefficient −1.76E−2 m{sup 3} C{sup −1} and the electrical conductivity 280 S cm{sup −1}. The thermal conductivity is 0.47 W m{sup −1} K{sup −1}, which is as low as one-third of the value observed in the bulk material. The doped P atoms occupy the interstitial positions between the two adjacent Te(1) layers connected by Van der Waals interaction in Bi{sub 2}Te{sub 3}. - Graphical abstract: Display Omitted - Highlights: • Phosphorus-doped Bi{sub 2}Te{sub 3} films were synthesized on a stainless-steel electrode by electrochemical deposition. • The thermal conductivity of the film is 0.47 W m{sup −1} K{sup −1}, which is one-third of the value observed in the bulk material. • The doped P atoms occupy the interstitial positions in Bi{sub 2}Te{sub 3}.
14. Substantial dust loss of bioavailable phosphorus from agricultural soils
Science.gov (United States)
Katra, Itzhak; Gross, Avner; Swet, Nitzan; Tanner, Smadar; Krasnov, Helena; Angert, Alon
2016-04-01
Phosphorus (P) is an essential element in terrestrial ecosystems. Knowledge on the role of dust in the biogeochemical cycling of phosphorus is very limited with no quantitative information on aeolian (by wind) P fluxes from soils. The aim of this study is to focus on P cycling via dust emissions under common land-use practices in an arid environment by integration of sample analyses and aeolian experiments. The experiments indicate significant P fluxes by PM10 dust due to agricultural land use. Even in a single wind-dust event at moderate velocity (7.0 m s-1), P flux in conventional agricultural fields can reach 1.83 kg km-2, that accumulates to a considerable amount per year at a regional scale. The results highlight a negative yearly balance in P content (up to hundreds kg km-2) in all agricultural soils, and thus more P nutrition is required to maintain efficient yield production. In grazing areas where no P nutrition is applied, the soil degradation process can lead to desertification. Emission of P from soil dust sources has significant implications for soil nutrient resources and management strategies in agricultural regions as well as for loading to the atmosphere and global biogeochemical cycles.
15. Inclusive and exclusive cross sections for multiple ionization by fast, highly charged ions in the independent-electron approximation
International Nuclear Information System (INIS)
Ben-Itzhak, I.; Gray, T.J.; Legg, J.C.; McGuire, J.H.
1988-01-01
Cross sections for the ionization of n of N electrons with equal single-electron ionization probability P are considered. When both N and the projectile charge q are large, the cross sections for single and double ionization are both found to be approximately linear in q at 1 MeVamu. The ratio of double-to-single-ionization cross sections is independent of q. Moreover, first-order perturbation theory for the single-electron ionization probability P, which varies as q 2 , is found to be applicable due to the damping of contributions with large P caused by factors of (1-P)/sup N/ - /sup n/. For large P there are differences between the inclusive probability P and the probability NP commonly used for a target with N electrons. Both of these probabilities differ significantly from the exclusive probability NP(1-P)/sup N/ -1 for the ionization of only one electron. For large N and large q, the exclusive ionization probabilities for removing exactly n of the N electrons tend to be concentrated in somewhat separate ranges of impact parameters b, defining impact-parameter ''windows.'' The windows which we obtain using the quantum-mechanical semiclassical-Coulomb-approximation (SCA) probabilities are similar to those using classical Monte Carlo calculations. Model calculations, based on analytic fits to the SCA probabilities, are used to obtain approximate analytic expressions for single- and double-ionization cross sections and for the impact-parameter windows
16. Acid Load and Phosphorus Homeostasis in CKD.
Science.gov (United States)
Khairallah, Pascale; Isakova, Tamara; Asplin, John; Hamm, Lee; Dobre, Mirela; Rahman, Mahboob; Sharma, Kumar; Leonard, Mary; Miller, Edgar; Jaar, Bernard; Brecklin, Carolyn; Yang, Wei; Wang, Xue; Feldman, Harold; Wolf, Myles; Scialla, Julia J
2017-10-01
The kidneys maintain acid-base homeostasis through excretion of acid as either ammonium or as titratable acids that primarily use phosphate as a buffer. In chronic kidney disease (CKD), ammoniagenesis is impaired, promoting metabolic acidosis. Metabolic acidosis stimulates phosphaturic hormones, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) in vitro, possibly to increase urine titratable acid buffers, but this has not been confirmed in humans. We hypothesized that higher acid load and acidosis would associate with altered phosphorus homeostasis, including higher urinary phosphorus excretion and serum PTH and FGF-23. Cross-sectional. 980 participants with CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Net acid excretion as measured in 24-hour urine, potential renal acid load (PRAL) estimated from food frequency questionnaire responses, and serum bicarbonate concentration urine phosphorus and calcium excretion and serum phosphorus, FGF-23, and PTH concentrations. Using linear and log-linear regression adjusted for demographics, kidney function, comorbid conditions, body mass index, diuretic use, and 24-hour urine creatinine excretion, we found that 24-hour urine phosphorus excretion was higher at higher net acid excretion, higher PRAL, and lower serum bicarbonate concentration (each Pphosphorus concentration was also higher with higher net acid excretion and lower serum bicarbonate concentration (each P=0.001). Only higher net acid excretion associated with higher 24-hour urine calcium excretion (Pphosphorus, or urine urea nitrogen excretion, when available. Possible residual confounding by kidney function or nutrition; urine phosphorus excretion was included in calculation of the titratable acid component of net acid excretion. In CKD, higher acid load and acidosis associate independently with increased circulating phosphorus concentration and augmented phosphaturia, but not consistently with FGF-23 or PTH
17. UV Ionizer for Neutral Wind Mass Spectrometers
Data.gov (United States)
National Aeronautics and Space Administration — Current neutral particle instrumentation relies on hot cathode filaments or an electron gun for ionizing the target medium. These ionization sources represent a...
18. A liquid ionization chamber using tetramethylsilane
International Nuclear Information System (INIS)
Engler, J.; Keim, H.
1983-12-01
First results with a liquid ionization chamber using tetramethylsilane (TMS) are presented. A stack of iron plates was tested with cosmic ray muons and the charge output for minimum ionizing particles was measured. (orig.) [de
19. Effects of dietary phosphorus deficiency on the abundance, phosphorus balance, and growth of Daphnia cucullata in three hypereutrophic Dutch lakes
NARCIS (Netherlands)
DeMott, W.R.; Gulati, R.D.; Van Donk, E.
2001-01-01
We studied population dynamics, phosphorus balance, and individual growth to evaluate limitation of Daphnia cucullata by dietary phosphorus (P) in three interconnected, hypereutrophic Dutch lakes. Consistent with the P-limitation hypothesis, declines in egg production and population density
20. Phosphorus analysis in milk samples by neutron activation analysis method
International Nuclear Information System (INIS)
Oliveira, R.M. de; Cunha, I.I.L.
1991-01-01
The determination of phosphorus in milk samples by instrumental thermal neutron activation analysis is described. The procedure involves a short irradiation in a nuclear reactor and measurement of the beta radiation emitted by phosphorus - 32 after a suitable decay period. The sources of error were studied and the established method was applied to standard reference materials of known phosphorus content. (author)
1. Phosphorus Uptake and Partitioning in Maize as Affected by Tillage ...
African Journals Online (AJOL)
Higher phosphorus concentrations were found in the ears than in the shoots and leaves at physiological maturity. Tillage x phospho-rus interactions influenced phosphorus partitioning in the ears and the leaves on the Dystric Cam-bisol but not on the Ferric Acrisol. PUE in the plant parts were significantly higher under ...
2. Surface runoff and phosphorus (P) loss from bamboo (Phyllostachys ...
African Journals Online (AJOL)
Jane
2011-08-24
Aug 24, 2011 ... The average bioavailable phosphorus (BAP) concentration of the runoff was 0.23 mg/l and the various phosphorus ... Key words: Phyllostachys pubescens, ecosystem, surface runoff, phosphorus (P) loss. INTRODUCTION .... runoff samples were used for total P (TP) determination following perchloric acid ...
3. Reaching ultra low phosphorus concentrations by filtration techniques
NARCIS (Netherlands)
Scherrenberg, S.M.
2011-01-01
This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and
4. 46 CFR 151.50-50 - Elemental phosphorus in water.
Science.gov (United States)
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design calculations...
5. Phosphorus flows and balances of the European Union Member States
NARCIS (Netherlands)
Dijk, van K.C.; Lesschen, J.P.; Oenema, O.
2016-01-01
Global society faces serious “phosphorus challenges” given the scarcity, essentiality, unequal global distribution and, at the same time, regional excess of phosphorus (P). Phosphorus flow studies can be used to analyze these challenges, providing insight into how society (re)uses and loses
6. Protein, energy and phosphorus supplementation of cattle fed low ...
African Journals Online (AJOL)
marked where phosphorus was given on its own and where it depressed voluntary feed intake by as much as 5,9%. (Treatment 7 versus 8). In combination with protein as the only other supplement (Treatment 3 versus 4), phosphorus did not stimulate or depress roughage intake. In contrast with energy and phosphorus, ...
7. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).
Science.gov (United States)
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for the...
8. Barium Isotopes in Single Presolar Grains
Science.gov (United States)
Pellin, M. J.; Davis, A. M.; Savina, M. R.; Kashiv, Y.; Clayton, R. N.; Lewis, R. S.; Amari, S.
2001-01-01
Barium isotopic compositions of single presolar grains were measured by laser ablation laser resonant ionization mass spectrometry and the implications of the data for stellar processes are discussed. Additional information is contained in the original extended abstract.
9. CALCULATION OF IONIZATION RATE COEFFICIENTS OF ...
African Journals Online (AJOL)
We use a simple numerical method to generate the ionization rates starting from the cross sections. These last are obtained by code FAC (Flexible Atomic Code). Our computation results will be compared with those published. Key words: Atomic data, radiative collisional Models, Ionization rate, cross Sections of ionization.
10. Progress on untargeted effects of ionizing irradiation
International Nuclear Information System (INIS)
Liu Jing; Chen Jihong; Li Wenjian
2010-01-01
The side effect of ionizing irradiation has been paid more attention with its widely using in tumor treating and mutation breeding. In recent years, untargeted effects induced by ionizing irradiation have become a hotspot of radiobiology. Here, according to reported results, we reviewed the types (genomic instability, bystander effect and adaptive response) and mechanisms of untargeted effects of ionizing irradiation in this paper. (authors)
11. 29 CFR 1926.53 - Ionizing radiation.
Science.gov (United States)
2010-07-01
... 29 Labor 8 2010-07-01 2010-07-01 false Ionizing radiation. 1926.53 Section 1926.53 Labor... § 1926.53 Ionizing radiation. (a) In construction and related activities involving the use of sources of ionizing radiation, the pertinent provisions of the Nuclear Regulatory Commission's Standards for...
12. Dynamics of the helium atom close to the full fragmentation threshold: Ionization excitation
International Nuclear Information System (INIS)
Bouri, C.; Selles, P.; Malegat, L.; Teuler, J.M.; Njock, M. Kwato; Kazansky, A.K.
2005-01-01
The hyperspherical R-matrix method with semiclassical outgoing waves, designed to provide accurate double-ionization cross sections, is extended to allow for the computation of ionization-excitation data of comparable quality. Accordingly, it appears now as a complete method for treating the correlated dynamics of two-electron atoms, in particular above their full fragmentation threshold. Cross sections σ n and asymmetry parameters β n are obtained for single photoionization of helium with excitation of the residual ion up to as high a level as n=50 at 0.1 eV above the double-ionization threshold. These data are extrapolated to infinite values of n in order to check widespread assumptions regarding this limit. Our data are found consistent with the assumed n -3 dependence of the partial ionization cross sections. However, the β ∞ =-0.636 obtained still lies far from the -1 value expected at the double-ionization threshold
International Nuclear Information System (INIS)
Popits, R.
1976-01-01
Fundamentals of nuclear physics are reviewed under the headings: obtaining of X-rays and their properties; modes of radioactive decay of natural or man-made radionuclides; radioactive neutron sources; nuclear fission as basis for devising nuclear reactors and weapons; thermonuclear reactions; cosmic radiation. Basic aspects of ionizing radiation interactions with matter are considered with regard to charged particles, photon radiation, and neutrons. (A.B.)
14. Electron-impact Ionization Of Li2 And Li+2
Energy Technology Data Exchange (ETDEWEB)
Colgan, James P [Los Alamos National Laboratory
2008-01-01
Electron-impact ionization cross sections for Li{sub 2} and Li{sup +}{sub 2} are calculated using a configuration-average distorted-wave method. Bound orbitals for the molecule and its ions are calculated using a single configuration self-consistent field method based on a linear combination of Slater-type orbitals. The bound orbitals are transformed onto a two-dimensional lattice ({tau}, {theta}), which is variable in the radial coordinate and constant in the angular coordinate, from which Hartree with local exchange potentials are constructed. The single particle Schrodinger equation is then solved for continuum distorted-waves with S-matrix boundary conditions. Total ionization cross sections for Li{sub 2} at an equilibrium internuclear separation of R = 5.0 and for Li{sup +}{sub 2} at an equilibrium internuclear separation of R = 5.9 are presented.
15. Position-sensitive ionization detectors for ionizing beams diagnostics
CERN Document Server
Artemiev, A N; Mikhailov, V; Rezvov, V; Yudin, L
2002-01-01
Ionizing detectors for on-line non-destructive monitoring of the geometric parameters of ionizing beams have been proposed. Such a detector can be used on a beamline with a residual gas pressure of about 10 sup - sup 3 -10 sup - sup 6 Torr. It measures the product of ionization of the residual gas by the beam under investigation. An electric field moves the ions through a narrow slit into an analyzer. The analyzer field transforms the energy distribution of the ions into a two-dimensional space distribution on the outer analyzer plane. An Open Image Converter Tube (ICT) with an amplifier consisting of two Micro Channel Plates (MCP) forms an image of the real beam cross-section. This image is registered by a video camera, processed and stored on a computer. The detectors were successfully tested on beams of charged particles with wide energy and intensity ranges and on synchrotron radiation beams. Codes developed give the distribution of the beam density along its cross-section, beam profiles, the position of ...
16. The effects of $\\alpha$-lactalbumin and whey protein concentrate on $\\alpha$-amino acids, calcium and phosphorus levels in blood and gastrointestinal tract of rats
OpenAIRE
Pantako, Odile; Amiot, Jean
2001-01-01
International audience; The effects of two dietary proteins on $\\alpha$-amino acids, calcium and phosphorus concentrations in plasma, stomach and intestine were investigated in rats trained to consume, in a single two-hour daily meal, diets containing $\\alpha$-lactalbumin ($\\alpha$-la) or whey protein concentrate (WPC) for two weeks. The results indicated that the concentrations of calcium and phosphorus in the gastrointestinal tract and that of $\\alpha$-amino acids in portal vein were not si...
17. Phosphorus retention capacity in red ferralitic soil.
Science.gov (United States)
Pérez, M M; Bossens, J; Rosa, E; Tack, F M G
2014-01-01
In this study the main physical-chemical characteristics of red ferralitic soil to use as substrate in subsurface wetlands was determined. The P-removal was evaluated in a short-term isotherm batch experiment and in a column percolation experiment. The acid characteristic and high content of iron minerals in the red ferralitic soil facilitated the phosphorus removal. Also the sorption isotherms at two different temperatures were obtained. The results showed that the sorption capacity increases with an increase in solution temperature from 25 to 35 °C. The experimental data were fitted to Langmuir and Freundlich models, having a better fit to the Freundlich isotherms. The maximum P-sorption capacities estimated using the Langmuir isotherm were 0.96 and 1.13 g/kg at 25 and 35 °C respectively. Moreover a column experiment was carried out at two different flows. Sequential extractions of the phosphorus-saturated soil indicated that phosphorus is mainly bound with iron or aluminum minerals. The results have demonstrated a good potential for red ferralitic soil for phosphorus removal from urban wastewater.
18. interaction between phosphorus fertilizer and arbuscular ...
African Journals Online (AJOL)
userpc
ABSTRACT. Field experiment was carried out in the Northern Guinea Savanna agro-ecology of Nigeria to examine the interaction between Phosphorus (P) fertilizer and Arbuscular Mycorrhizal Fungal. (AMF) inoculants on cassava yield components. The experiment was laid in a split plot design with P fertilizers as main plot ...
19. 28 PHOSPHORUS FORMS AND DISTRIBUTION IN SELECTED ...
African Journals Online (AJOL)
sys01
Coleman and Thomas (1967). Total phosphorus in the soils was determined by perchloric acid digestion (Jackson, 1958) and organic P was estimated by the difference between 13 M HCL extractable inorganic P, before and after ignition, by the method of Leg and Black (1955). Inorganic P was fractionated by method of.
20. Nanotubes based on monolayer blue phosphorus
KAUST Repository
Montes Muñoz, Enrique
2016-07-08
We demonstrate structural stability of monolayer zigzag and armchair blue phosphorus nanotubes by means of molecular dynamics simulations. The vibrational spectrum and electronic band structure are determined and analyzed as functions of the tube diameter and axial strain. The nanotubes are found to be semiconductors with a sensitive indirect band gap that allows flexible tuning.
1. Phosphorus Requirement for Colonization by Arbuscular ...
African Journals Online (AJOL)
Therefore, this study was conducted to investigate the effect of phosphorus (P) concentrations on arbuscular mycorrhizal fungi (AMF) colonization and growth of two perennial crops (Catha edulis and Ensete ventricosum) and four multipurpose agroforestry trees (Cordia africana, Croton macrostachyus, Erythrina brucei and ...
2. Phosphate recycling in the phosphorus industry
NARCIS (Netherlands)
Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.
2004-01-01
The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the
3. Phosphorus adsorption characteristics of selected southeastern ...
African Journals Online (AJOL)
The phosphorus adsorption characteristics of selected Southeastern Nigerian soils from Ikom, Bende and Ihiagwa were evaluated. P adsorption isotherm was obtained by shaking soil samples with 0, 10, 20, 30, 40 and 50 ppm P in 0.01M CaCl2 solution. P adsorption maxima (b), affinity constant (k), buffering capacity and P ...
4. Phosphorus enhances aluminium tolerance in both aluminium ...
African Journals Online (AJOL)
Seedlings growing in acid soils suffer both phosphorus (P) deficiency and aluminium (Al) toxicity stresses. An experiment was conducted to study the effects of Al and P interaction on Al-tolerant (ET8) and Al-sensitive (ES8) wheat genotypes in an acid soil. This study aimed to determine the interactive effect of Al and P in soil ...
5. Phosphorus recovery from sewage sludge char ash
NARCIS (Netherlands)
Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, Sascha R.A.; Kootstra, A.M.J.
2014-01-01
Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching
6. Phosphorus supplementation of Karakul sheep grazing natural ...
African Journals Online (AJOL)
The phosphorus (P) status of adult Karakul ewes grazing natural pasture was determined by measuring the P content of blood, saliva, faecal, and bone samples. The ewes were divided into four groups of 20 ewes each, viz. ewes supplemented with P+ and P- which lambed during May and October. All lambs born were ...
7. A review of phosphorus removal structures
DEFF Research Database (Denmark)
Penn, Chad; Chagas, Isis; Klimeski, Aleksandar
2017-01-01
Controlling dissolved phosphorus (P) losses to surface waters is challenging as most conservation practices are only effective at preventing particulate P losses. As a result, P removal structures were developed to filter dissolved P from drainage water before reaching a water body. While many P ...
8. The future of phosphorus in our hands
NARCIS (Netherlands)
Shepherd, J.G.; Kleemann, Rosanna; Bahri-Esfahani, Jaleh; Hudek, Lee; Suriyagoda, Lalith; Vandamme, Elke; Dijk, van K.C.
2016-01-01
We live in a global phosphorus (P) system paradox. P access is becoming increasingly limiting, leading to food insecurity but at the same time an over-application or abundance of P in many agricultural and urban settings is causing environmental degradation. This has been recognised in the
9. Phosphorus recycling from the waste sector
NARCIS (Netherlands)
Ruijter, de F.J.; Dijk, Van W.; Curth-van Middelkoop, J.C.; Reuler, van H.
2015-01-01
An efficient use of phosphorus (P) is necessary as phosphate rock is a finite resource and P is essential for crop production. From the waste sector in the Netherlands, 23 Mkg P is sequestered in landfill, incineration ashes and cement. Flows containing P are discussed, together with options to
10. Use of reactive materials to bind phosphorus
NARCIS (Netherlands)
Chardon, W.J.; Groenenberg, J.E.; Temminghoff, E.J.M.; Koopmans, G.F.
2012-01-01
Phosphorus (P) losses from agricultural soils have caused surface water quality impairment in many regions of the world, including The Netherlands. Due to the large amounts of P accumulated in Dutch soils, the generic fertilizer and manure policy will not be sufficient to reach in time the surface
11. Flotation of uraniferous phosphorus ore from Itataia
International Nuclear Information System (INIS)
Aquino, J.A. de
1984-01-01
Flotation conditions, in laboratory and pilot scale, were established in a sample of Itataia uraniferous phosphorus ore which was basically constitute of apatite and calcite. The system of reagents-tall oil, collamil and sodium silicate-was studied in rougher, scavenger and cleaner stage. (M.A.C.) [pt
12. Process for uranium recovery in phosphorus compounds
International Nuclear Information System (INIS)
Demarthe, J.M.; Solar, Serge.
1980-01-01
Process for uranium recovery in phosphorus compounds with an organic phase containing a dialkylphosphoric acid. A solubilizing agent constituted of an heavy alcohol or a phosphoric acid ester or a tertiary phosphine oxide or octanol-2, is added to the organic phase for solubilization of the uranium and ammonium dialkyl pyrophosphate [fr
13. Phosphorus effect on fracture properties of structural steels
International Nuclear Information System (INIS)
Goritskij, V.M.; Guseva, I.A.
1985-01-01
Phosphorus content is studied for its effect on fracture peculiarities and fracture toughness. It is supposed that the phosphorus effect on ductile fractures is associated with phosphorus segregation on the ferrite-carbide interfaces. An increase of the phosphorus content in heat-treated 10KhSND steel from 0.020 up to 0.043 wt.% results in a decrease of the pore size and asub(p) value. Close linear correlation is established between critical temperature of embrittlement T 50 and √ asub(p) or √ KC values for a number of structural steels with different phosphorus content
14. Biological phosphorus uptake under anoxic and aerobic conditions
DEFF Research Database (Denmark)
Kerrn-Jespersen, Jens Peter; Henze, Mogens
1993-01-01
Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...... taken up by the phosphorus accumulating bacteria during the anaerobic phase affects the total denitrification rate, as well as the rate at which the phosphorus accumulating bacteria take up phosphate under anoxic conditions. The tests were conducted as batch experiments in 21. reactors with activated...... conditions. There was a linear relationship between the amount of acetate taken up in the anaerobic phase, the denitrification rate and the phosphorus uptake rate....
15. Phosphorus Dimerization in Gallium Phosphide at High Pressure
Energy Technology Data Exchange (ETDEWEB)
2018-02-09
Using combined experimental and computational approaches, we show that at 43 GPa and 1300 K gallium phosphide adopts the super-Cmcm structure, here indicated with its Pearson notation oS24. First-principles enthalpy calculations demonstrate that this structure is more thermodynamically stable above ~20 GPa than previously proposed polymorphs. Here, in contrast to other polymorphs, the oS24 phase shows a strong bonding differentiation and distorted fivefold coordination geometries of both P atoms. The shortest bond of the phase is a single covalent P–P bond measuring 2.171(11) Å at synthesis pressure. Phosphorus dimerization in GaP sheds light on the nature of the super-Cmcm phase and provides critical new insights into the high-pressure polymorphism of octet semiconductors. Bond directionality and anisotropy explain the relatively low symmetry of this high-pressure phase.
16. Cell fusion by ionizing radiation
International Nuclear Information System (INIS)
Khair, M.B.
1993-08-01
The relevance and importance of cell fusion are illustrated by the notion that current interest in this phenomenon is shared by scientists in quite varied disciplines. The diversity of cellular membrane fusion phenomena could provoke one to think that there must be a multitude of mechanisms that can account for such diversity. But, in general, the mechanism for the fusion reaction itself could be very similar in many, or even all, cases. Cell fusion can be induced by several factors such as virus Sendai, polyethylene glycol, electric current and ionizing radiation. This article provides the reader with short view of recent progress in research on cell fusion and gives some explanations about fusion mechanisms. This study shows for the first time, the results of the cell fusion induced by ionizing radiations that we have obtained in our researches and the work performed by other groups. (author). 44 refs
17. Laser ionization of molecular clusters
International Nuclear Information System (INIS)
Desai, S.; Feigerle, C.S.
1995-01-01
Multiphoton ionization coupled with mass spectrometry was used to investigate molecular cluster distributions. Three examples will be discussed in this presentation. First, in studies of neat nitric oxide clusters, (NO) m , an interesting odd-even intensity alternation was observed and will be discussed in terms of electron-pairing considerations. In a separate study, the binary clusters comprising nitric oxide and methane preferentially form a stoichiometric cluster made up of repeating units of (NO) 2 CH 4 . These presumably represent a particularly strongly bound open-quotes van der Waalsclose quotes subunit. Finally, in similar studies of neat carbon disulfide clusters, (CS 2 ) m , additional photon absorption after the two-photon ionization step stimulates a series of intracluster ion-molecular reactions leading to formation of S m + and (CS) m + polymers, as well as intermediate species such as S m + (CS 2 ). This molecular cluster analogue of open-quotes laser snowclose quotes will be described in detail
18. LONGITUDINAL IONIZATION COOLING WITHOUT WEDGES
International Nuclear Information System (INIS)
BERG, J.S.
2001-01-01
The emittance of a muon beam must be reduced very rapidly due to the finite lifetime of the muons. The most effective known way to accomplish this is ionization cooling. It is straightforward to reduce transverse emittance through ionization cooling, but the reducing the longitudinal emittance is more challenging. Longitudinal cooling is necessary for a muon collider, and would be helpful for a neutrino factory. The method traditionally proposed for longitudinal cooling is emittance exchange involving wedges of absorber material: the longitudinal emittance is reduced at the cost of increased transverse emittance. The larger transverse emittance can then be reduced straightforwardly. An alternative method is proposed here, which does not require wedges of material but instead makes slight modifications to the standard transverse cooling lattice. We demonstrate a lattice which is a slight modification to a standard Super FOFO transverse cooling lattice, which has linear eigenvalues all of which have magnitude less than one
19. Phosphorus reduction by sifting fish waste meal
Directory of Open Access Journals (Sweden)
Ronaldo Lima de Lima
2014-10-01
Full Text Available Fish meal is widely included in animal feed because it contains ideal essential amino acids profile, it is rich in energy, essential fatty acids, vitamins and minerals and with >80% apparent protein digestibility in peneid shrimp. In human nutrition, studies are investigating the inclusion of fish meal in snacks, cakes, breads and cookies, as an enrichment in calcium, phosphorus, iron, protein and, especially, omega-3 fatty acids. Omega-3 fatty acids reduces heart diseases and have antithrombotic and anti-inflammatory properties (eicosapentaenoic acid, and are essential to the formation of brain tissue and retina in infants and are important during pregnancy and lactation (docosahexaenoic acid. Fish meal produced from fish waste is rich in minerals (phosphorus, which may cause eutrophication and impair water quality in aquaculture. The aim of this study was to reduce phosphorus content from commercial fish meal produced from waste by sifting (0.60 - 1.00 - 1.18 - 1.40 - 2.36 and 3.35mm mesh sizes. Fish meal samples were collected monthly for 24 months. Proximate composition of subsamples per mesh size was compared to the unsieved sample. Results indicate that sifting through a 0.60mm sieve total phosphorus and ash contents were reduced up to 32% and 36%, respectively, further to increase protein content up to 20%. Average composition of the subsamples was 47.04% ash, 5.56% of total phosphorus and 39.45% protein, suggesting that the residue of the fractionation may be marketed as a mineral and protein supplement.
20. Ionization potentials some variations, implications and applications
CERN Document Server
Ahrens, L H
1983-01-01
Ionization Potentials: Some Variations, Implications and Applications covers several aspects of ionization potential that is a highly significant parameter in controlling the properties of electric discharge. Comprised of 17 chapters, the book covers topic relevant to ionization potentials, such as properties, concepts, and applications, in order to understand and fully comprehend all aspects of ionization potential. The opening chapter is a review of ionization potentials and a discussion of trends and features. The succeeding chapters then tackle complex topics such as the s and p electrons;
1. Ionizing radiation perception by insects
International Nuclear Information System (INIS)
Campanhola, C.
1980-04-01
2. The dosimetry of ionizing radiation
CERN Document Server
1990-01-01
A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.
3. Impact of Fish Farming on Phosphorus in Reservoir Sediments.
Science.gov (United States)
Jia, Binyang; Tang, Ya; Tian, Liyan; Franz, Leander; Alewell, Christine; Huang, Jen-How
2015-11-18
Fish farming has seriously influenced the aquatic environment in Sancha reservoir in SW China since 1985 and has been strongly restricted since 2005. Thus, phosphorus speciation in a sediment core dated between 1945 and 2010 at cm-resolution and in surface sediments from Sancha reservoir may allow us track how fish farming impacts phosphorus dynamics in lake sediments. Fish farming shifts the major binding forms of phosphorus in sediments from organic to residual phosphorus, which mostly originated from fish feed. Sorption to metal oxides and association with organic matters are important mechanisms for phosphorus immobilisation with low fish farming activities, whereas calcium-bound phosphorous had an essential contribution to sediment phosphorus increases under intensive fish framing. Notwithstanding the shifting, the aforementioned phosphorus fractions are usually inert in the lake environment, therefore changing phosphorus mobility little. The use of fish feed and water-purification reagents, the most important additives for fish farming, introduce not only phosphorus but also large amounts of sand-sized minerals such as quartz into the lake, to which phosphorus weakly sorbs. The sand-sized minerals as additional sorbents increase the pool of easily mobilisable phosphorus in sediments, which will slow down the recovery of reservoir water due to its rapid re-mobilisation.
4. Ionization of H Rydberg atoms
International Nuclear Information System (INIS)
Hillermier, C.F.; Bluemental, R.; Smilansky, U.
1991-07-01
Concepts from the theory of transient chaos are applied to study the classical ionization process of one dimensional model of kicked hydrogen Rydberg atoms. The phase-space dynamics is represented by a mapping T which is proved to be hyperbolic. The fraction of atoms not ionized after time t, P B (t), decays asymptotically according to P B (t)∼t -α with α ∼ 1.65. The observed algebraic decay, which seems to contradict the hyperbolicity of T, is explained by (i) the symbolic dynamics of T consists of a countably infinite number of symbols and (ii) the invariant manifold of phase-space points which never ionize is an anomalously scaling fractal. Therefore, the one-dimensional kicked hydrogen atom provides a counterexample to the hypothesis that algebraic decay marks regular dynamics, whereas hyperbolic systems decay exponentially. The algebraic decay is reproduced by an analytically solvable diffusion model which predicts α = 3/2. Replacing zero-width δ-kicks by smooth finite-width pulses, the mapping T is no longer completely hyperbolic, and a subset of phase-space is regular. For this case we observe that P B (t) shows a transition between two power-law decays with α ∼ 1.65 for short times and α ∼ 2.1 for long times where the effect of the regular domain is felt. (author)
5. Ionization-based detectors for gas chromatography.
Science.gov (United States)
Poole, Colin F
2015-11-20
The gas phase ionization detectors are the most widely used detectors for gas chromatography. The column and makeup gases commonly used in gas chromatography are near perfect insulators. This facilitates the detection of a minute number of charge carriers facilitating the use of ionization mechanisms of low efficiency while providing high sensitivity. The main ionization mechanism discussed in this report are combustion in a hydrogen diffusion flame (flame ionization detector), surface ionization in a plasma (thermionic ionization detector), photon ionization (photoionization detector and pulsed discharge helium ionization detector), attachment of thermal electrons (electron-capture detector), and ionization by collision with metastable helium species (helium ionization detector). The design, response characteristics, response mechanism, and suitability for fast gas chromatography are the main features summarized in this report. Mass spectrometric detection and atomic emission detection, which could be considered as ionization detectors of a more sophisticated and complex design, are not discussed in this report. Copyright © 2015 Elsevier B.V. All rights reserved.
6. On the ionization of interstellar magnesium
International Nuclear Information System (INIS)
1977-01-01
It has been shown that two concentric ionization zones of interstellar magnesium must exist around each star: internal, with a radius coinciding with that of the zone of hydrogen ionization Ssub(H); and external, with a radius greater than Ssub(H), by one order. Unlike interstellar hydrogen, interstellar magnesium is ionized throughout the Galaxy. It also transpires that the ionizing radiation of ordinary hot stars cannot provide for the observed high degree of ionization of interstellar magnesium. The discrepance can be eliminated by assuming the existence of circumstellar clouds or additional ionization sources of interstellar magnesium (X-ray background radiation, high-energy particles, etc.). Stars of the B5 and BO class play the main role in the formation of ionization zones of interstellar magnesium; the contribution of O class stars is negligible (<1%). (Auth.)
7. Loss of ions in cavity ionization chambers
International Nuclear Information System (INIS)
Takata, N.; Tran, N.T.; Kim, E.; Marsoem, P.; Kurosawa, T.; Koyama, Y.
2005-01-01
Ion losses due to initial recombination, volume recombination, and back diffusion were each determined by measurements and calculations for different size cylindrical ionization chambers and spherical ionization chambers. By measuring signal currents from these ionization chambers irradiated with 60 Co gamma rays, two groups of ion losses were obtained. (Group 1) Ion loss due to initial recombination and diffusion, which changes proportionally to the inverse of the voltage applied to the ionization chambers; (and group 2) ion loss due to volume recombination, which changes proportionally to the inverse of the square of the applied voltage. The diffusion loss was obtained separately by computing electric field distributions in the ionization chambers. It was found that diffusion loss is larger than initial recombination loss for the cylindrical ionization chambers and vise versa for the spherical ionization chambers
8. Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?
International Nuclear Information System (INIS)
Jarvie, Helen P.; Neal, Colin; Withers, Paul J.A.
2006-01-01
Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P + suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication
9. Ionization of a two-electron atom in a strong electromagnetic field
International Nuclear Information System (INIS)
Ovodova, O.V.; Popov, A.M.; Tikhonova, O.V.
1997-01-01
A one-dimensional model of a helium atom in an intense field of a femtosecond electromagnetic pulse has been constructed using the Hartree technique. 'Exact' calculations have been compared to the approximations of 'frozen' and 'passive' electrons. A nonmonotonic dependence of the single-electron ionization probability on the radiation intensity has been detected. Minima in the ionization probability are due to multiphoton resonances between different atomic states due to the dynamic Stark effect. We suggest that the ionization suppression is due to the interference stabilization in this case
10. Analysis of abused drugs by selected ion monitoring: quantitative comparison of electron impact and chemical ionization
International Nuclear Information System (INIS)
Foltz, R.L.; Knowlton, D.A.; Lin, D.C.K.; Fentiman, A.F. Jr.
1975-01-01
A comparison was made of the relative sensitivities of electron impact and chemical ionization when used for selected ion monitoring analysis of commonly abused drugs. For most of the drugs examined chemical ionization using ammonia as the reactant gas gave the largest single m/e ion current response per unit weight of sample. However, if maximum sensitivity is desired it is important to evaluate electron impact and chemical ionization with respect to both maximum response and degree of interference from background and endogenous materials
11. Double electron ionization in Compton scattering of high energy photons by helium atoms
International Nuclear Information System (INIS)
Amusia, M.Y.; Mikhailov, A.I.
1995-01-01
The cross section for double-electron ionization of two-electron atoms and ions in Compton scattering of high energy photons is calculated. It is demonstrated that its dependence on the incoming photon frequency is the same as that for single-electron ionization. The ratio of open-quotes double-to-singleclose quotes ionization in Compton scattering was found to be energy independent and almost identical with the corresponding value for photoionization. For the He atom it is 1.68%. This surprising result deserves experimental verification
12. Phosphorus recycling from an unexplored source by polyphosphate accumulating microalgae and cyanobacteria – a step to phosphorus security in agriculture
Directory of Open Access Journals (Sweden)
Chandan eMukherjee
2015-12-01
Full Text Available Phosphorus (P, an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50-100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp. and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale.
13. Potential Impact of Dietary Choices on Phosphorus Recycling and Global Phosphorus Footprints: The Case of the Average Australian City
Science.gov (United States)
Metson, Geneviève S.; Cordell, Dana; Ridoutt, Brad
2016-01-01
Changes in human diets, population increases, farming practices, and globalized food chains have led to dramatic increases in the demand for phosphorus fertilizers. Long-term food security and water quality are, however, threatened by such increased phosphorus consumption, because the world’s main source, phosphate rock, is an increasingly scarce resource. At the same time, losses of phosphorus from farms and cities have caused widespread water pollution. As one of the major factors contributing to increased phosphorus demand, dietary choices can play a key role in changing our resource consumption pathway. Importantly, the effects of dietary choices on phosphorus management are twofold: First, dietary choices affect a person or region’s “phosphorus footprint” – the magnitude of mined phosphate required to meet food demand. Second, dietary choices affect the magnitude of phosphorus content in human excreta and hence the recycling- and pollution-potential of phosphorus in sanitation systems. When considering options and impacts of interventions at the city scale (e.g., potential for recycling), dietary changes may be undervalued as a solution toward phosphorus sustainability. For example, in an average Australian city, a vegetable-based diet could marginally increase phosphorus in human excreta (an 8% increase). However, such a shift could simultaneously dramatically decrease the mined phosphate required to meet the city resident’s annual food demand by 72%. Taking a multi-scalar perspective is therefore key to fully exploring dietary choices as one of the tools for sustainable phosphorus management. PMID:27617261
14. Adiabatic theory of Wannier threshold laws and ionization cross sections
International Nuclear Information System (INIS)
Macek, J.H.; Ovchinnikov, S.Y.
1994-01-01
Adiabatic energy eigenvalues of H 2 + are computed for complex values of the internuclear distance R. The infinite number of bound-state eigenenergies are represented by a function ε(R) that is single valued on a multisheeted Riemann surface. A region is found where ε(R) and the corresponding eigenfunctions exhibit harmonic-oscillator structure characteristic of electron motion on a potential saddle. The Schroedinger equation is solved in the adiabatic approximation along a path in the complex R plane to compute ionization cross sections. The cross section thus obtained joins the Wannier threshold region with the keV energy region, but the exponent near the ionization threshold disagrees with well-accepted values. Accepted values are obtained when a lowest-order diabatic correction is employed, indicating that adiabatic approximations do not give the correct zero velocity limit for ionization cross sections. Semiclassical eigenvalues for general top-of-barrier motion are given and the theory is applied to the ionization of atomic hydrogen by electron impact. The theory with a first diabatic correction gives the Wannier threshold law even for this case
15. Second-order Born approximation for the ionization of molecules by electron and positron impact
Energy Technology Data Exchange (ETDEWEB)
Dal Cappello, C. [Universite Paul Verlaine-Metz, Laboratoire de Physique Moleculaire et des Collisions, Institut Jean Barriol (FR2843), 1 Boulevard Arago, F-57078 Metz Cedex 3 (France); Rezkallah, Z.; Houamer, S. [Laboratoire de Physique Quantique et Systemes Dynamiques, Departement de Physique, Faculte des Sciences Universite Ferhat Abbas, Setif 19000 (Algeria); Charpentier, I. [Universite Paul Verlaine-Metz, Laboratoire de Physique et Mecanique des Materiaux UMR 7554, Ile du Saulcy, F-57045 Metz Cedex 1 (France); Hervieux, P. A. [Institut de Physique et Chimie des Materiaux de Strasbourg, 23 Rue du Loess, BP 43, F-67034 Strasbourg Cedex 2 (France); Ruiz-Lopez, M. F. [Nancy-University, Equipe de Chimie et Biochimie Theoriques, UMR CNRS-UHP 7565, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Dey, R. [Max-Planck Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Roy, A. C. [School of Mathematical Sciences, Ramakrishna Mission Vivekananda University, Belur Math 711202, West Bengal (India)
2011-09-15
Second-order Born approximation is applied to study the ionization of molecules. The initial and final states are described by single-center wave functions. For the initial state a Gaussian wave function is used while for the ejected electron it is a distorted wave. Results of the present model are compared with recent (e,2e) experiments on the water molecule. Preliminary results are also presented for the ionization of the thymine molecule by electrons and positrons.
16. The location and nature of accumulated phosphorus in seven sludges from activated sludge plants which exhibited enhanced phosphorus removal
International Nuclear Information System (INIS)
Buchan, L.
1981-01-01
Electron microscopy combined with the energy dispersive analysis of X-rays (EDX) has been used to examine the nature of the phosphorus accumulated in sludges from seven activated sludge plants exhibiting enhanced phosphorus removal. Large phosphorus accumulations were located in identical structures in the sludges examined. The phosphorus was located in large electron-dense bodies, within large bacterial cells which were characteristically grouped in clusters. The calcium:phosphorus ratio of these electron-dense bodies precluded them from being any form of calcium phosphate precipitate. Quantitative analysis indicated that the electron-dense bodies contained in excess of 30% phosphorus. The results obtained are supportive of a biological mechanism of enhanced phosphorus uptake in activated sludge
17. Identifying phosphorus hot spots: A spatial analysis of the phosphorus balance as a result of manure application.
Science.gov (United States)
Parchomenko, Alexej; Borsky, Stefan
2018-05-15
In this paper, we analyze the phosphorus balance as a result of manure application on the parish level for Denmark and investigate its local geographic distribution. For our analysis, we determine phosphorus loads for the five main animal groups and the phosphorus demand of the fifteen major crop categories. Our results show that there is a large variability in the phosphorus balance within Denmark. Due to industry agglomeration statistically significant hot spots appear mainly along the west coast, while cold spots are predominantly present on southern and eastern coasts towards the Baltic Sea. The proximity of oversupply areas to water bodies and other environmentally sensitive areas reinforces the need for further phosphorus regulation. Our findings show the importance of a combined spatially targeted regulation, which allows different levels of phosphorus application depending on local economic and environmental circumstances in combination with subsidizing manure processing technologies in phosphorus hot spots. Copyright © 2018 Elsevier Ltd. All rights reserved.
18. Effect of phosphorus stress on Microcystis aeruginosa growth and phosphorus uptake.
Directory of Open Access Journals (Sweden)
Sajeela Ghaffar
Full Text Available This study was designed to advance understanding of phosphorus regulation of Microcystis aeruginosa growth, phosphorus uptake and storage in changing phosphorus (P conditions as would occur in lakes. We hypothesized that Microcystis growth and nutrient uptake would fit classic models by Monod, Droop, and Michaelis-Menten in these changing conditions. Microcystis grown in luxury nutrient concentrations was transferred to treatments with phosphorus concentrations ranging from 0-256 μg P∙L-1 and luxury nitrogen. Dissolved phosphorus concentration, cell phosphorus quota, P uptake rate and cell densities were measured at day 3 and 6. Results showed little relationship to predicted models. Microcystis growth was asymptotically related to P treatment from day 0-3, fitting Monod model well, but negatively related to P treatment and cell quota from day 3-6. From day 0-3, cell quota was negatively related to P treatments at <2 μg∙L-1, but increased slightly at higher P. Cell quota decreased greatly in low P treatments from day 3-6, which may have enabled high growths in low P treatments. P uptake was positively and linearly related to P treatment during both periods. Negative uptake rates and increases in measured culture phosphorus concentrations to 5 μg∙L-1 in the lowest P treatments indicated P leaked from cells into culture medium. This leakage during early stages of the experiment may have been sufficient to stimulate metabolism and use of intracellular P stores in low P treatments for rapid growth. Our study shows P regulation of Microcystis growth can be complex as a result of changing P concentrations, and this complexity may be important for modeling Microcystis for nutrient and ecosystem management.
19. Ionization and photofragmentation of Ru3(CO)12 and Os3(CO)12
International Nuclear Information System (INIS)
Schalk, Oliver; Josefsson, Ida; Odelius, Michael; Richter, Robert; Prince, Kevin C.; Mucke, Melanie
2015-01-01
In this paper, we use a combination of photoelectron spectroscopy, mass spectrometry, and density functional theory calculations to get a detailed understanding of valence single and double ionization and the subsequent dissociation processes. This is exemplified on benchmark systems, trimetallo-dodecacarbonyls M 3 (CO) 12 with M = Ru, Os, where the energy remaining in the molecule after photoionization can be retrieved by measuring the degree of fragmentation of the molecular ion. The intensity of different mass peaks can thus be directly related to ionization cross sections obtained by photoelectron spectroscopy. We find that the M—CO dissociation energy rises as the number of CO ligands decreases due to dissociation. Moreover, ionization of the CO ligands has a higher cross section than that of the metal center for both single and double ionization. After advanced fragmentation, a CO bond can break and the carbon atom remains bonded to the metal core. In addition, we found that the valence ionization cross sections of M 3 (CO) 12 are maximal at about 40 eV photon energy thus showing a more pronounced shape resonance than Ru and Os-complexes with a single metal atom center. Finally, an np → nd giant resonance absorption causes a significant increase of the ionization cross section above 50 eV for Ru 3 (CO) 12
20. Effects of parenteral phosphorus dose restriction in preterm infants.
Science.gov (United States)
McNelis, K; Viswanathan, S
2016-06-22
In response to a national shortage of parenteral phosphorus solutions (2013), a hospital-wide phosphorus dose restriction strategies was implemented which included judicious use of phosphorus in preterm infants birth weight and no parenteral phosphorus in preterm infants >1250 g birth weight unless they have a critically low phosphorus level. To study the effect of parenteral phosphorus dose restriction in preterm infants admitted to the neonatal intensive care unit. Preterm infants (≤35 weeks birth gestation and ≤2500 g birth weight) who received parenteral nutrition, survived >1 week and had no major congenital anomalies were studied. Clinical and laboratory data in the first 4 weeks of life of infants admitted during the parenteral phosphorus shortage (cases) were compared to infants who were admitted 6 months prior to the shortage (controls). Twenty consecutive cases were compared to 40 consecutive controls. Cases had lower serum phosphorus levels, higher serum alkaline phosphatase levels, and need for greater inotropic support compared to controls. These differences were significant only in preterm infants with birth weight >1250 g, the group who received more parenteral phosphorus dose restriction while they were similar in preterm infants with birth weight <1250 g. The modest effects of phosphorus dose restriction may become more clinically important if shortage is prolonged or severe or if it involves extreme preterm infants.
1. Performance of fertigation technique for phosphorus application in cotton
Directory of Open Access Journals (Sweden)
M. Aslam
2009-05-01
Full Text Available Low native soil phosphorus availability coupled with poor utilization of added phosphorus is one of the major constraints limiting the productivity of the crops. With a view of addressing this issue, field studies were conducted to compare the relative efficacy of broadcast and fertigation techniques for phosphorus application during 2005-2006 using cotton as a test crop. Two methods of phosphorus application i.e. broadcast and fertigation were evaluated using five levels of P2O5 (0, 30, 45, 60 and 75 kg P2O5 ha -1. Fertigation showed an edge over broadcast method at all levels of phosphorus application. The highest seed cotton yield was recorded with 75 kg P2O5 ha-1. Fertilizer phosphorus applied at the rate of 60 kg ha-1 through fertigation produced 3.4 tons ha-1 of seed cotton yield, which was statistically identical to 3.3 tons recorded with 75 kg ha-1 of broadcast phosphorus. Agronomic performance of phosphorus was influenced considerably by either method of fertilizer application. The seed cotton yield per kg of fertigation phosphorus was 48% higher than the corresponding broadcast application. The results of these studies showed that fertigation was the most efficient method of phosphorus application compared with the conventional broadcast application of fertilizers.
2. Patient education for phosphorus management in chronic kidney disease
Science.gov (United States)
2013-01-01
Objectives: This review explores the challenges and solutions in educating patients with chronic kidney disease (CKD) to lower serum phosphorus while avoiding protein insufficiency and hypercalcemia. Methods: A literature search including terms “hyperphosphatemia,” “patient education,” “food fatigue,” “hypercalcemia,” and “phosphorus–protein ratio” was undertaken using PubMed. Results: Hyperphosphatemia is a strong predictor of mortality in advanced CKD and is remediated via diet, phosphorus binders, and dialysis. Dietary counseling should encourage the consumption of foods with the least amount of inorganic or absorbable phosphorus, low phosphorus-to-protein ratios, and adequate protein content, and discourage excessive calcium intake in high-risk patients. Emerging educational initiatives include food labeling using a “traffic light” scheme, motivational interviewing techniques, and the Phosphate Education Program – whereby patients no longer have to memorize the phosphorus content of each individual food component, but only a “phosphorus unit” value for a limited number of food groups. Phosphorus binders are associated with a clear survival advantage in CKD patients, overcome the limitations associated with dietary phosphorus restriction, and permit a more flexible approach to achieving normalization of phosphorus levels. Conclusion: Patient education on phosphorus and calcium management can improve concordance and adherence and empower patients to collaborate actively for optimal control of mineral metabolism. PMID:23667310
3. Efficiency of phosphate fertilization to maize crop in high phosphorus content soil, evaluated by {sup 32}P tracer
Energy Technology Data Exchange (ETDEWEB)
Trevizam, Anderson R.; Alvarez Villanueva, Felipe C.; Silva, Maria Ligia de S.; Muraoka, Takashi [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Fertilidade do Solo]. E-mails: [email protected]; [email protected]; [email protected]; [email protected]
2007-07-01
Application of high dosis of phosphorus (P) in agricultural soils is justified by its intense fixation by the soil clays, which reduce availability to crops. The objective of this research was to evaluate the response of maize crops to five rates of triple superphosphate in a soil with high available phosphorus content. Portions of 2 dm{sup 3} of soil (Typic Quartzipisamment) with 75 mg kg{sup -1} of available phosphorus and pH 7.00, collected from the upper 0-20 cm layer, were placed in plastic pots, received solution containing 5.55 MBq (150 {mu}Ci) of {sup 32}P and incubated for 7 days. Then 0, 250, 500, 1000 and 4000 mg P kg{sup -1} as triple superphosphate was added to soil in the respective pots and incubated for 15 days keeping the soil moisture to 60 % of the field capacity. Maize (Zea mays L.) plants, single hybrid P30F80, were grown for 50 days (after germination), collected, oven dried, weighed and ground in a Wiley mill for analysis of total P content and {sup 32}P radioactivity. The maize dry matter increased with triple superphosphate rates. The phosphorus content and accumulation in the maize plants increased with triple superphosphate rate up to 4000 mg kg{sup -1}. The percentage of phosphorus derived from the fertilizer ranged from 79 to 97% and consequently the phosphorus derived from soil decreased with increasing application of triple superphosphate. In spite of soil high P available content, maize plants responded to applied phosphorus rates. (author)
4. [Research progress on phosphorus budgets and regulations in reservoirs].
Science.gov (United States)
Shen, Xiao; Li, Xu; Zhang, Wang-shou
2014-12-01
Phosphorus is an important limiting factor of water eutrophication. A clear understanding of its budget and regulated method is fundamental for reservoir ecological health. In order to pro- mote systematic research further and improve phosphorus regulation system, the budget balance of reservoir phosphorus and its influencing factors were concluded, as well as conventional regulation and control measures. In general, the main phosphorus sources of reservoirs include upstream input, overland runoff, industrial and domestic wastewater, aquaculture, atmospheric deposition and sediment release. Upstream input is the largest phosphorus source among them. The principal output path of phosphorus is the flood discharge, the emission load of which is mainly influenced by drainage patterns. In addition, biological harvest also can export a fraction of phosphorus. There are some factors affecting the reservoir phosphorus balance, including reservoirs' function, hydrological conditions, physical and chemical properties of water, etc. Therefore, the phosphorus budgets of different reservoirs vary greatly, according to different seasons and regions. In order to reduce the phosphorus loading in reservoirs, some methods are carried out, including constructed wetlands, prefix reservoir, sediment dredging, biomanipulation, etc. Different methods need to be chosen and combined according to different reservoirs' characteristics and water quality management goals. Thus, in the future research, it is reasonable to highlight reservoir ecological characteristics and proceed to a complete and systematic analysis of the inherent complexity of phosphorus budget and its impact factors for the reservoirs' management. Besides, the interaction between phosphorus budget and other nutrients in reservoirs also needs to be conducted. It is fundamental to reduce the reservoirs' phosphorus loading to establish a scientific and improved management system based on those researches.
5. Visualizing alternative phosphorus scenarios for future food security
Directory of Open Access Journals (Sweden)
Tina-Simone Neset
2016-10-01
Full Text Available The impact of global phosphorus scarcity on food security has increasingly been the focus of scientific studies over the past decade. However, systematic analyses of alternative futures for phosphorus supply and demand throughout the food system are still rare and provide limited inclusion of key stakeholders. Addressing global phosphorus scarcity requires an integrated approach exploring potential demand reduction as well as recycling opportunities. This implies recovering phosphorus from multiple sources, such as food waste, manure and excreta, as well as exploring novel opportunities to reduce the long-term demand for phosphorus in food production such as changing diets. Presently, there is a lack of stakeholder and scientific consensus around priority measures. To therefore enable exploration of multiple pathways and facilitate a stakeholder dialogue on the technical, behavioral and institutional changes required to meet long-term future phosphorus demand, this paper introduces an interactive web-based tool, designed for visualizing global phosphorus scenarios in real-time. The interactive global phosphorus scenario tool builds on several demand and supply side measures that can be selected and manipulated interactively by the user. It provides a platform to facilitate stakeholder dialogue to plan for a soft landing and identify a suite of concrete priority options, such as investing in agricultural phosphorus use efficiency, or renewable fertilizers derived from phosphorus recovered from wastewater and food waste, to determine how phosphorus demand to meet future food security could be attained on a global scale in 2040 and 2070. This paper presents four example scenarios, including (1 the potential of full recovery of human excreta, (2 the challenge of a potential increase in non-food phosphorus demand, (3 the potential of a decreased animal product consumption, and (4 the potential decrease in phosphorus demand from increased efficiency
6. Visualizing Alternative Phosphorus Scenarios for Future Food Security.
Science.gov (United States)
Neset, Tina-Simone; Cordell, Dana; Mohr, Steve; VanRiper, Froggi; White, Stuart
2016-01-01
The impact of global phosphorus scarcity on food security has increasingly been the focus of scientific studies over the past decade. However, systematic analyses of alternative futures for phosphorus supply and demand throughout the food system are still rare and provide limited inclusion of key stakeholders. Addressing global phosphorus scarcity requires an integrated approach exploring potential demand reduction as well as recycling opportunities. This implies recovering phosphorus from multiple sources, such as food waste, manure, and excreta, as well as exploring novel opportunities to reduce the long-term demand for phosphorus in food production such as changing diets. Presently, there is a lack of stakeholder and scientific consensus around priority measures. To therefore enable exploration of multiple pathways and facilitate a stakeholder dialog on the technical, behavioral, and institutional changes required to meet long-term future phosphorus demand, this paper introduces an interactive web-based tool, designed for visualizing global phosphorus scenarios in real time. The interactive global phosphorus scenario tool builds on several demand and supply side measures that can be selected and manipulated interactively by the user. It provides a platform to facilitate stakeholder dialog to plan for a soft landing and identify a suite of concrete priority options, such as investing in agricultural phosphorus use efficiency, or renewable fertilizers derived from phosphorus recovered from wastewater and food waste, to determine how phosphorus demand to meet future food security could be attained on a global scale in 2040 and 2070. This paper presents four example scenarios, including (1) the potential of full recovery of human excreta, (2) the challenge of a potential increase in non-food phosphorus demand, (3) the potential of decreased animal product consumption, and (4) the potential decrease in phosphorus demand from increased efficiency and yield gains in
7. Controlled Sculpture of Black Phosphorus Nanoribbons.
Science.gov (United States)
Masih Das, Paul; Danda, Gopinath; Cupo, Andrew; Parkin, William M; Liang, Liangbo; Kharche, Neerav; Ling, Xi; Huang, Shengxi; Dresselhaus, Mildred S; Meunier, Vincent; Drndić, Marija
2016-06-28
Black phosphorus (BP) is a highly anisotropic allotrope of phosphorus with great promise for fast functional electronics and optoelectronics. We demonstrate the controlled structural modification of few-layer BP along arbitrary crystal directions with sub-nanometer precision for the formation of few-nanometer-wide armchair and zigzag BP nanoribbons. Nanoribbons are fabricated, along with nanopores and nanogaps, using a combination of mechanical-liquid exfoliation and in situ transmission electron microscopy (TEM) and scanning TEM nanosculpting. We predict that the few-nanometer-wide BP nanoribbons realized experimentally possess clear one-dimensional quantum confinement, even when the systems are made up of a few layers. The demonstration of this procedure is key for the development of BP-based electronics, optoelectronics, thermoelectrics, and other applications in reduced dimensions.
8. Phosphorus kinetics in ovine fed with different phosphorus sources, using the isotopic dilution technique
International Nuclear Information System (INIS)
Vitti, D.M.S.S.; Abdalla, A.L.; Meirelles, C.F.
1992-01-01
Phosphorus kinetics in fluids and tissues of sheep was studied. Sixteen castrated sheep were kept in metabolism cages, receiving a semipuried diet containing as phosphorus sources dicalcium phosphate (BIC), monoammonium phosphate (MAP), superphosphate (SPT) and Tapita phosphate (TAP) 200 μCi P-32 was intravenously injected in each sheep and blood and feces were collected for eight days. From the specific activities in feces and plasma the endogenous phosphorus and the absorption coefficient were calculated. plasma P-32 half-life was determined. Nine days after injection the animals were killed and liver, kidney and muscle and bone samples were collected. P-32 retention and specific activities in tissues were determined. Endogenous phosphorus and absorption coefficient values were 54.44 ± 15.31 mh/kg live weight and 0.60; 47.98 ± 12.44 and 0.56; 39.70 ± 7.29 and 0.49; 59.11 ± 17.12 and 0.58 respectively bor BIC, MAP, TAP and SPT. P-32 retention by tissues was 0.29 ± 0.09; 0.27 ± 0.06; 0.16 ± 0.04 and 0.08 ± 0.03 dose/g fresh matter, respectively for bone, liver, kidney and muscle. It was concluded that animals which received TAP showed differences in absorption, distribution and P-32 retention by fluids and tissues. Phosphorus availability was lower for this source. (author)
9. Comprehensive Utilization of Iron and Phosphorus from High-Phosphorus Refractory Iron Ore
Science.gov (United States)
Sun, Yongsheng; Zhang, Qi; Han, Yuexin; Gao, Peng; Li, Guofeng
2018-02-01
An innovative process of coal-based reduction followed by magnetic separation and dephosphorization was developed to simultaneously recover iron and phosphorus from one typical high-phosphorus refractory iron ore. The experimental results showed that the iron minerals in iron ore were reduced to metallic iron during the coal-based reduction and the phosphorus was enriched in the metallic iron phase. The CaO-SiO2-FeO-Al2O3 slag system was used in the dephosphorization of metallic iron. A hot metal of 99.17% Fe and 0.10% P was produced with Fe recovery of 84.41%. Meanwhile, a dephosphorization slag of 5.72% P was obtained with P recovery of 67.23%. The contents of impurities in hot metal were very low, and it could be used as feedstock for steelmaking after a secondary refining. Phosphorus in the dephosphorization slag mainly existed in the form of a 5CaO·P2O5·SiO2 solid solution where the P2O5 content is 13.10%. At a slag particle size of 20.7 μm (90% passing), 94.54% of the P2O5 could be solubilized in citric acid, indicating the slag met the feedstock requirements in phosphate fertilizer production. Consequently, the proposed process achieved simultaneous Fe and P recovery, paving the way to comprehensive utilization of high-phosphorus refractory iron ore.
10. Space Flight Ionizing Radiation Environments
Science.gov (United States)
Koontz, Steve
2017-01-01
The space-flight ionizing radiation (IR) environment is dominated by very high-kinetic energy-charged particles with relatively smaller contributions from X-rays and gamma rays. The Earth's surface IR environment is not dominated by the natural radioisotope decay processes. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of space radiation environments, beginning with the space radiation environment on the International Space Station and moving outward through the Van Allen belts to cislunar space. The benefits and limitations of radiation shielding materials will also be summarized.
11. XUV ionization of aligned molecules
Energy Technology Data Exchange (ETDEWEB)
Kelkensberg, F.; Siu, W.; Gademann, G. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Rouzee, A.; Vrakking, M. J. J. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Max-Born-Institut, Max-Born Strasse 2A, D-12489 Berlin (Germany); Johnsson, P. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Department of Physics, Lund University, Post Office Box 118, SE-221 00 Lund (Sweden); Lucchini, M. [Department of Physics, Politecnico di Milano, Istituto di Fotonica e Nanotecnologie CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Lucchese, R. R. [Department of Chemistry, Texas A and M University, College Station, Texas 77843-3255 (United States)
2011-11-15
New extreme-ultraviolet (XUV) light sources such as high-order-harmonic generation (HHG) and free-electron lasers (FELs), combined with laser-induced alignment techniques, enable novel methods for making molecular movies based on measuring molecular frame photoelectron angular distributions. Experiments are presented where CO{sub 2} molecules were impulsively aligned using a near-infrared laser and ionized using femtosecond XUV pulses obtained by HHG. Measured electron angular distributions reveal contributions from four orbitals and the onset of the influence of the molecular structure.
12. Tunneling Ionization of Diatomic Molecules
DEFF Research Database (Denmark)
Svensmark, Jens Søren Sieg
2016-01-01
When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...
13. Advanced Thin Ionization Calorimeter (ATIC)
Science.gov (United States)
Wefel, John P.
1998-01-01
This is the final report for NASA grant NAGW-4577, "Advanced Thin Ionization Calorimeter (ATIC)". This grant covered a joint project between LSU and the University of Maryland for a Concept Study of a new type of fully active calorimeter to be used to measure the energy spectra of very high energy cosmic rays, particularly Hydrogen and Helium, to beyond 1014 eV. This very high energy region has been studied with emulsion chamber techniques, but never investigated with electronic calorimeters. Technology had advanced to the point that a fully active calorimeter based upon Bismuth Germanate (BGO) scintillating crystals appeared feasible for balloon flight (and eventually space) experiments.
14. Phosphorus introduction mechanism in electrodeposited cobalt films
International Nuclear Information System (INIS)
Kravtchenko, Jean-Francois
1973-01-01
The cathodic reduction of hypophosphite, phosphite and phosphate ions was studied using chrono-potentiometry and voltammetry. Then cobalt was deposited at constant current from a bath containing one of these three compounds. The current, while giving an electrodeposition of cobalt, also enhances at the same time a chemical deposition of cobalt. It is shown that high coercive forces in cobalt films are much more related to this chemical deposition than to the simple fact that the films contain some phosphorus. (author) [fr
15. Modelling phosphorus retention in lakes and reservoirs
Czech Academy of Sciences Publication Activity Database
Hejzlar, Josef; Šámalová, K.; Boers, P.; Kronvang, B.
2006-01-01
Roč. 6, 5-6 (2006), s. 487-494 ISSN 1567-7230 R&D Projects: GA AV ČR IAA3017301; GA AV ČR 1QS600170504 Grant - others:EU(XE) EVK1-CT-2001-00096; MSM(CZ) 6007665801 Institutional research plan: CEZ:AV0Z60170517 Keywords : phosphorus * retention * reservoir Subject RIV: DA - Hydrology ; Limnology
16. Regulating phosphorus from the agricultural sector
DEFF Research Database (Denmark)
Hansen, Line Block; Hansen, Lars Gårn; Rubæk, Gitte Holton
2010-01-01
do not take into account the importance of P already stored in the soils. Phosphorus stored in the soils is the major source of P losses to surface waters, but at the same time crucial for the soils ability to sustain a viable crop production. Even if measures on P losses from agricultural areas......) and the interactions between these two sources. In this paper such a model is outlined and discussed....
17. p-type ZnO films with solid-source phosphorus doping by molecular-beam epitaxy
International Nuclear Information System (INIS)
Xiu, F.X.; Yang, Z.; Mandalapu, L.J.; Liu, J.L.; Beyermann, W. P.
2006-01-01
Phosphorus-doped p-type ZnO films were grown on r-plane sapphire substrates using molecular-beam epitaxy with a solid-source GaP effusion cell. X-ray diffraction spectra and reflection high-energy electron diffraction patterns indicate that high-quality single crystalline (1120) ZnO films were obtained. Hall and resistivity measurements show that the phosphorus-doped ZnO films have high hole concentrations and low resistivities at room temperature. Photoluminescence (PL) measurements at 8 K reveal a dominant acceptor-bound exciton emission with an energy of 3.317 eV. The acceptor energy level of the phosphorus dopant is estimated to be 0.18 eV above the valence band from PL spectra, which is also consistent with the temperature dependence of PL measurements
18. Phosphorus in the dense interstellar medium
International Nuclear Information System (INIS)
Turner, B.E.; Tsuji, T.; Bally, J.; Guelin, M.; Cernicharo, J.
1990-01-01
An observational study was made of interstellar (and circumstellar) phosphorus chemistry by means of (1) a survey of PN in energetic star-forming regions (several new detections); (2) a search for PN in cold cloud cores; and (3) a search for HPO, HCP, and PH3 in interstellar and circumstellar sources. The results are consistent with previously developed ion-molecule models of phosphorus chemistry and imply large depletion factors for P in dense clouds: about 1000 in warm star-forming cores and more than 10,000 in cold cloud cores. Thermochemical equilibrium models have been developed for the P chemistry in C-rich and O-rich environments, and it is found that HCP contains all the phosphorus in the C-rich case. The search for HCP in IRC 10216 yields an upper limit which, taken together with the recent detection of CP, implies significant depletion of HCP onto grains. Depletion factors for first- and second-row elements in diffuse and dense interstellar clouds are summarized, and an overall picture of circumstellar and interstellar grain and gas-phase processes is proposed to explain the depletions of N, O, C, S, Si, P, and in particular the high depletions of Si and P. 101 refs
19. RAYLEIGH-TAYLOR INSTABILITY IN PARTIALLY IONIZED COMPRESSIBLE PLASMAS
Energy Technology Data Exchange (ETDEWEB)
Diaz, A. J. [Instituto de Astrofisica de Canarias, 38205, C/ Via Lactea, s/n, La Laguna, Tenerife (Spain); Soler, R. [Centre for Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium); Ballester, J. L., E-mail: [email protected], E-mail: [email protected], E-mail: [email protected] [Departament de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)
2012-07-20
We study the modification of the classical criterion for the linear onset and growing rate of the Rayleigh-Taylor instability (RTI) in a partially ionized plasma in the two-fluid description. The plasma is composed of a neutral fluid and an electron-ion fluid, coupled by means of particle collisions. The governing linear equations and appropriate boundary conditions, including gravitational terms, are derived and applied to the case of the RTI in a single interface between two partially ionized plasmas. The limits of collisionless, no gravity, and incompressible fluids are checked before addressing the general case. We find that both compressibility and ion-neutral collisions lower the linear growth rate, but do not affect the critical threshold of the onset of the RTI. The configuration is always unstable when a lighter plasma is below a heavier plasma regardless the value of the magnetic field strength, the ionization degree, and the ion-neutral collision frequency. However, ion-neutral collisions have a strong impact on the RTI growth rate, which can be decreased by an order of magnitude compared to the value in the collisionless case. Ion-neutral collisions are necessary to accurately describe the evolution of the RTI in partially ionized plasmas such as prominences. The timescale for the development of the instability is much longer than in the classical incompressible fully ionized case. This result may explain the existence of prominence fine structures with life times of the order of 30 minutes. The timescales derived from the classical theory are about one order of magnitude shorter and incompatible with the observed life times.
20. Ionization of molecular hydrogen in ultrashort intense laser pulses
International Nuclear Information System (INIS)
Vanne, Yulian V.
2010-01-01
A novel ab initio numerical approach is developed and applied that solves the time-dependent Schroedinger equation describing two-electron diatomic molecules (e.g. molecular hydrogen) exposed to an intense ultrashort laser pulse. The method is based on the fixed-nuclei and the non-relativistic dipole approximations and aims to accurately describe both correlated electrons in full dimensionality. The method is applicable for a wide range of the laser pulse parameters and is able to describe both few-photon and many-photon single ionization processes, also in a non-perturbative regime. A key advantage of the method is its ability to treat the strong-field response of the molecules with arbitrary orientation of the molecular axis with respect to the linear-polarized laser field. Thus, this work reports on the first successful orientation-dependent analysis of the multiphoton ionization of H 2 performed by means of a full-dimensional numerical treatment. Besides the investigation of few-photon regime, an extensive numerical study of the ionization by ultrashort frequency-doubled Ti:sapphire laser pulses (400 nm) is presented. Performing a series of calculations for different internuclear separations, the total ionization yields of H 2 and D 2 in their ground vibrational states are obtained for both parallel and perpendicular orientations. A series of calculations for 800 nm laser pulses are used to test a popular simple interference model. Besides the discussion of the ab initio numerical method, this work considers different aspects related to the application of the strong-field approximation (SFA) for investigation of a strong-field response of an atomic and molecular system. Thus, a deep analysis of the gauge problem of SFA is performed and the quasistatic limit of the velocity-gauge SFA ionization rates is derived. The applications of the length-gauge SFA are examined and a recently proposed generalized Keldysh theory is criticized. (orig.) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7045266628265381, "perplexity": 6689.448127612248}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794865023.41/warc/CC-MAIN-20180523004548-20180523024548-00590.warc.gz"} |
https://www.infoq.com/articles/evaluating-hyperledger-composer/?itm_source=articles_about_Adaptive-Leadership&itm_medium=link&itm_campaign=Adaptive-Leadership | InfoQ Homepage Articles Evaluating Hyperledger Composer
# Evaluating Hyperledger Composer
This item in chinese
### Key Takeaways
• Only a very narrow subset of use cases is appropriate for this technology.
• The way that Hyperledger Fabric uses MVCC (multiversion concurrency control) when validating write batches is safe enough for financial applications in a decentralized ledger but may not scale efficiently enough in order to be attractive to B2C startups.
• Avoid this technology if you can make all of your transactions idempotent.
• This technology is still somewhat immature.
• Even though this is an open-source project, there are currently some limitations in choice of cloud provider when moving to a production environment (that could change).
I have been following the three-year-old Hyperledger Fabric open-source project since its code base moved to GitHub about two years ago. The Hyperledger projects are hosted by the Linux Foundation and sponsored mostly by IBM. They promote the use of what are known as private, or permissioned, blockchains. With a public blockchain, the first anonymous miner who solves a cryptographic puzzle gets to commit the next block of ledger entries to the chain. Private blockchains solve the consensus problem among authenticated peers using algorithms such as Raft or Paxos.
With a blockchain, you get CRUD-style access to the ledger. You also get the ability to store mini programs known as smart contracts on the ledger. When a transaction is submitted to a smart contract, all ledger state-mutating operations executed within the chaincode are atomic — either all operations get committed or none of them do. If the underlying ledger data accessed by the chaincode has been changed by the time that the operations made by the chaincode are to be committed, then the transaction is aborted. This happens automatically and is a big part of the value to writing smart contracts.
The same folks who released Hyperledger Fabric also released another open-source project, Hyperledger Composer, which makes it easy for developers to write chaincode for Hyperledger Fabric and the DApps (decentralized applications) that can call them.
## Why now?
Thoughtworks is a technology consulting company (acquired by Apax Partners) that markets itself as "a community of passionate individuals whose purpose is to revolutionize software design, creation and delivery". Twice a year, they release a Technology Radar report that recommends certain technologies be put on hold, assessed, put on trial, or adopted. Volume 18 of this Technology Radar (pdf), published in May 2018, placed Hyperledger Composer in the trial ring, which they define as "Worth pursuing. It is important to understand how to build up this capability. Enterprises should try this technology on a project that can handle the risk."
In my role as a software architect, I evaluate emerging technology, and Hyperledger Composer made it onto my personal radar. Every time I evaluate an emerging technology, I use it to implement a rudimentary news feed microservice. Each of these microservices are feature identical and are load-tested in the exact same manner. In this way, I can make reasonable statements about the performance characteristics of any specific technology in comparison with the other technologies. I chose the problem domain of a news feed because of its familiarity and ubiquity in social networks and because it is complicated enough to require non-trivial solutions yet simple enough to understand without getting lost in implementation minutiae. I publish the source code for these microservices, along with the source code needed to load-test them and to collect and analyze the performance results, in a freely available repository on GitHub. In the spirit of scientific peer review, I encourage you to clone the repo and reproduce the results for yourself.
## Building the test microservice
Hyperledger Composer allows you to write smart contracts in server-side JavaScript. It makes available a native client library by which Node.js applications can access the ledger and submit transactions to these smart contracts. For the purposes of this experiment, I used an already developed Node.js microservice (see server/feed4 in the repo) as the control. I copied the source code for that microservice to a new folder (see server/feed7/micro-service in the repo) then I replaced all references to MySQL, Redis, and Cassandra with calls to the Hyperledger Composer client API. It is the feed7 project that serves as the test in this experiment. Both projects use Elasticsearch because one of the requirements of each news-feed service is a keyword-based search, and a blockchain is not appropriate for that. Like most of the other microservices in this repo, the feed7 microservice uses Swagger to define its REST API. The specification can be found in the server/swagger/news.yaml file.
With Hyperledger Composer, you create a business network that consists of a data model, a set of transactions that manipulate the data model, and a set of queries by which those transactions can access data within the model. Hyperledger Composer works with Hyperledger Fabric, whose basic network consists of CouchDB, the default peer, the business network peer, a certificate authority service, and an orderer. The feed7 microservice accesses Hyperledger Fabric in the context of this business network, which you can find in the server/feed7/business-network folder.
Figure 1: Feed7 components (the test).
async function broadcastParticipants(tx) {
const factory = getFactory();
const created = Date.now();
const now = new Date();
const k = tx.sender.participantId + '|' + created + '|';
const outboundRegistry = await getAssetRegistry('info.glennengstrand.Outbound');
const ok = 'Outbound:' + k + Math.random();
const inboundRegistry = await getAssetRegistry('info.glennengstrand.Inbound');
var o = factory.newResource('info.glennengstrand', 'Outbound', ok);
o.created = now;
o.subject = tx.subject;
o.story = tx.story;
o.sender = tx.sender;
for (i = 0; i < friends.length; i++) {
const friend = friends[i];
const ik = 'Inbound:' + k + Math.random();
var inb = factory.newResource('info.glennengstrand', 'Inbound', ik);
inb.created = now;
inb.subject = tx.subject;
inb.story = tx.story;
inb.recipient = friend.to;
}
}
Code Sample 1: A smart contract.
The Hyperledger Composer API that is intended to be called within a smart contract closely resembles the API that is intended to be called by the Node.js DApp, but there are some interesting differences. Within the smart contract, you must use the async/await mechanism, but within the DApp, you had to use promises. Smart contracts always had to use predefined queries but DApp code could build a query dynamically and run that. When querying or retrieving either a participant or asset from the DApp, you had to include the constant "PID:" as a part of the key but not when accessing the same data from chaincode.
function submitTransaction(bizNetworkConnection, transaction, from, subject, story, callback, retry) {
const elastic = require('../repositories/elastic');
bizNetworkConnection.submitTransaction(transaction)
.then((result) => {
const retVal = {
"from": from,
"occurred": Date.now(),
"subject": subject,
"story": story
};
elastic.index(from, story);
callback(null, retVal);
}).catch(() => {
setTimeout(() => {
submitTransactionRetry(bizNetworkConnection, transaction, from, subject, story, callback, 2 * retry);
}, retry + Math.floor(Math.random() * Math.floor(1000)));
});
}
bizNetworkConnection.connect(process.env.CARD_NAME)
.then((bizNetworkDefinition) => {
const factory = bizNetworkDefinition.getFactory();
transaction.sender = factory.newRelationship('info.glennengstrand', 'Broadcaster', 'PID:' + args.body.value.from);
transaction.subject = args.body.value.subject;
transaction.story = args.body.value.story;
submitTransaction(bizNetworkConnection, transaction, args.body.value.from, args.body.value.subject, args.body.value.story, callback, 2000);
});
}
Code Sample 2: A DApp calling a smart contract.
In the DApp source code, you may notice all this retry logic when submitting a transaction. That is because Hyperledger Fabric uses MVCC (multiversion concurrency control) when validating write batches and will easily throw a read conflict error. What you do to resolve that is to sleep a slightly randomized amount of time then retry the transaction.
## Testing the microservice under load
Both the control and the test use the same load-test application, which you can find in the client/load folder of the repo. The load test creates 10 participants in an eternal loop, and gives each participant anywhere from two to four friends. It has each participant broadcast 10 news-feed items, each of which consists of 150 randomly generated numbers. The load-test app spins up three threads, each doing this process 90% of the time. The other 10% is testing the search functionality.
Instead of calling the news-feed microservice directly, the load-test application calls an open-source API gateway called Kong, which proxies each request from the load-test application to the news-feed microservice. Kong is configured to use the http-log plugin in order to send request and response logs for each call to another microservice, which in turn sends the performance-related parts to Elasticsearch in batches. You can find the source code for the Kong logger microservice in the client/perf4 folder.
I used Kibana to visualize the performance data, including throughput, average latency, and percentile latency. Whenever possible, I always collected summaries of performance metrics from two hours of data.
Figure 2: Per-minute throughput of outbound post requests for a test (i.e., Hyperledger Composer and Fabric) experiment.
Figure 3: Per-minute average of latency of outbound post requests for a test (i.e., Hyperledger Composer and Fabric) experiment.
I deployed the control twice, both times in EC2 using m4.xlarge instances; one time when the feed4 service was running in a Docker container and another time when it wasn’t. The Docker version experienced 6% less throughput and almost no difference in latency. I also deployed the test twice, both times in EC2 using m4.xlarge instances for Kong, Cassandra (used by Kong), Elasticsearch, and the load-test application. The first test deployed Hyperledger Fabric, Composer, and the feed7 business network and microservice on an m4.xlarge and the second test used an m4.2xlarge, to see the performance differences in scaling up.
Figure 4: Feed7 deployment (the test).
To allow for valid comparative analysis, and because production configurations were not readily available, both the control and the test used developer configurations for everything. There exists an AWS CloudFormation template for Hyperledger Fabric, but it is deploying the basic network, which is Hyperledger-speak for a developer configuration. The only online documentation for a production configuration that I could find, outside of advertisements for IBM Cloud, were a couple of blogs on Hacker Noon by some folks from VMware. Those blogs claimed a production configuration and a diagram indicated that the orderer was backed by Kafka, but the configtx.yaml file in the referenced GitHub repo shows an OrdererType of solo, not Kafka. That suggests a developer configuration. A comment in the source code says, "The solo consensus scheme is very simple, and allows only one consenter for a given chain. It accepts messages being delivered via Order/Configure, orders them, and then uses the blockcutter to form the messages into blocks before writing to the given ledger."
## Performance results
There is both good and bad news for Hyperledger when it comes to performance under load. Here is the bad news: the Hyperledger version of the news feed demonstrated over 300 times less throughput and was three orders of magnitude slower than the traditional version. But the good news is that doubling the hardware capacity for the Hyperledger version yielded a 20% improvement in throughput and almost halved the latency.
The control sustained over 13,000 outbound post requests (i.e., a news-feed broadcast) per minute (RPM). Average latency was 4 ms and the 99th percentile was 9 ms. The test experienced on average 29 outbound post requests per minute for the m4.xlarge and 38 for the m4.2xlarge. The average latency was 4.7 s for the m4.xlarge and 3.2 s for the m4.2xlarge. The 99th percentile latency was 10.2 s for the m4.xlarge and 4.9 s for the m4.2xlarge.
Figure 5: Outbound-post comparative performance summary. Latency numbers are in milliseconds.
There are some other inefficiencies that I need to cover here. The CPU and performance-related metrics on the control quickly reached steady state while the same metrics on the test got worse and worse over time. The biggest offender with CPU was the default peer process in Fabric. This was surprising because the microservice always accessed the news-feed business network whose corresponding peer container was not as CPU intensive. Perhaps the default peer is used to endorse transactions? I could find no way to remove it from the configuration. In a production configuration, you would have multiple peers, otherwise the ledger would not be decentralized.
For both the test and the control, the microservice will eventually crash, once the SSD for the database runs out of available storage. For the control, that happens in the Cassandra database after almost 30 million outbound posts have occurred. For the test, that happens in the CouchDB database after about 4,000 outbound posts have occurred. The SSD storage for both the control and the test have the same capacity, which is 20 GB. Clearly, storage efficiency is not currently a primary concern of the developers contributing to the Hyperledger Fabric project.
## Conclusion
Originally, I believed that the news-feed application would be a good use case for a blockchain. The primary action of the load-test application is appending friends and appending news-feed items, which sounds very similar to appending to a ledger. Now, however, I believe that analogy to be superficial. The major concern for blockchains is to prevent what is known as the double-spend problem — what good is a blockchain that cannot prevent participants from spending the same money twice? For public blockchains, that problem is handled using unspent transaction outputs, or UTXO. Hyperledger Fabric addresses the problem via MVCC on the read sets when validating write batches. Fabric does have inefficiencies that can be addressed as it matures, but I believe that this use of MVCC in order to prevent double spending is an inherent cause for the low throughput and high latency. For all intents and purposes, the news-feed transactions are essentially idempotent. There are no significant consequences if two participants friend themselves in a different order or multiple times, or broadcast items to each other in a different order or multiple times. Fabric is allocating a lot of CPU time and memory to prevent a problem that has no significant impact on a news feed.
This evaluation leads me to believe that the future of software development will not be eaten by blockchains. There is only a very narrow subset of use cases that justify the high computing costs inherent in automatic, guaranteed, distributed concurrency control and validation. Basically, you need to require a consortium marketplace where idempotent transactions are not a possibility. While evaluating Hyperledger Composer at this time has some merit, the current level of maturity makes committing to a production release in the near future highly problematic. The Hyperledger projects are all open source but at the time of this writing there appear to be limitations in choice of cloud provider when progressing to a production environment.
Glenn Engstrand is a Software Architect at Adobe Systems, Inc.. His focus is working with engineers in order to deliver scalable, server side, 12 factor compliant application architectures. Glenn was a breakout speaker at Adobe's internal Advertising Cloud developer's conferences in 2018 and 2017 and at the 2012 Lucene Revolution conference in Boston. He specializes in breaking monolithic applications up into micro-services and in deep integration with Real-Time Communications infrastructure.
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• ##### Hyperledger Fabric Use Cases
by Baiju Jacob /
• ##### Re: Hyperledger Fabric Use Cases
by Glenn Engstrand /
• ##### Re: Hyperledger Data Privacy & Throughput
by Baiju Jacob /
• ##### Cloud Restrictions Clarification
by Baiju Jacob /
• ##### Re: Cloud Restrictions Clarification
by Glenn Engstrand /
• ##### Re: Cloud Restrictions Clarification
by Baiju Jacob /
• ##### Re: Cloud Restrictions Clarification
by Glenn Engstrand /
• ##### Re: Cloud Restrictions Clarification
by Baiju Jacob /
• ##### Hyperledger Fabric Use Cases
by Baiju Jacob /
Your message is awaiting moderation. Thank you for participating in the discussion.
Hello Glenn, Thank You very much for an informative assessment of the performance of Hyperledger network. Composer is a very good tool for building POCs but if you are working on Production grade network, it is best to use raw Fabric which will give you more flexibility. Endorsing peers in Fabric Network are those where the smart contracts are deployed. Based on the endorsement policy, it will run on each organisation's endorsing peers required in the policy. This is a critical decision while designing and sizing the peer nodes in the network.
There is a significant difference in the use cases for public chains and private/permissioned chains. Permissioned chains are used between organisations where there is a trust issue between them which is causing enormous delays. This could be reporting of a serious event in a Clinical trial for pharmas or for tracebality of a defective perishable lot in a food supply chain. These are necessarily not high throughput scenarios but the complexity of reconciliation in these processes mean that it takes weeks and months today which has financial and public consequences.
In short many of the use cases for blockchain cannot and may not be equated or compared with current use cases and cannot be tested with similar benchmarks. It is to be used where automating trust gives big dividends and eliminates months of audits/reconciliations or when the truth of the data is very critical for a right outcome. There are plenty of use cases for this and many of them may just be an add on to existing applications which will greatly optimise your business process
• ##### Re: Hyperledger Fabric Use Cases
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Thank you, Baiju, for your insights into blockchain use cases. It never occurred to me that permissioned blockchains could help with workflow traceability involving high value assets whose responsibility is shared by multiple organizations. I would imagine that some challenges might present themselves when reconciling that traceability with privacy focused regulations such as HIPAA and GDPR but I suspect that those are solveable problems.
I wonder what other broad use cases could be more easily addressed by blockchains? Scenarios where high throughput and low latency is not required. Perhaps other readers here could share their experiences.
• ##### Re: Hyperledger Data Privacy & Throughput
by Baiju Jacob /
Your message is awaiting moderation. Thank you for participating in the discussion.
Hello Glenn,
As you rightly pointed out, the immutability of Blockchain has raised concerns for Data Privacy and has run into challenges with privacy centered regulations like GDPR. The good news is that Hyperledger Fabric V1.2 released in July 2018 introduces 'private data collection' which we believe could solve most of the challenges. Private Data Collection if properly designed and implemented could be used for private sensitive data which are required to build the trust and finalise the outcome at the time of the transaction, which can be removed or erased depending on the need at a later date without affecting the integrity of the chain. We have test implemented it and will apply this in some of the upcoming real use cases and will keep you posted.
Regarding throughput it will be directly related to use case. If you have a use case where you have to collect endorsements from multiple organisations across the globe endorsement and network latency could be high compared to transaction which has a leaner endorsement policy. Similarly your commit latency could possibly be improved by a better design of Key Value store and ordering latency could be improved using adequately sized Kafka based ordering service.
So I wont rule out all high through put use cases but some may have to wait till more improvement happens in the later releases. Our experience shows that many of the real use cases currently being worked on are not for replacing existing apps but to do something which they could never do before and many of them are integrating to existing apps.
• ##### Cloud Restrictions Clarification
by Baiju Jacob /
Your message is awaiting moderation. Thank you for participating in the discussion.
Another point I missed in my reply is on the conclusion that it is locked into one cloud provider. This is not accurate. All the components of Hyperledger are available as docker images and you can build up your network on your choice of cloud or on premise servers. It could even include multiple clouds and in house datacenters. Obviously you need the expertise to build/connect this network. But it is possible and has been done. Obviously the commercial cloud providers are not going to advertise this :). There is definitely a need to have better management tools to make this easier for all. Hyperledger Cello is a project under the foundation which is working on this and should address this soon.
• ##### Re: Cloud Restrictions Clarification
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Permit me to clarify, Baiju. This article never made the "conclusion that it is locked into one cloud provider." What I said was "at the time of this writing there appear to be limitations in choice of cloud provider when progressing to a production environment." There is a lot of activity in this space and cloud vendors are rapidly making positioning statements when it comes to enterprise blockchains. Who knows what the future may hold?
I'm glad that you believe it to be possible to build your own production worthy networks on premises or manage them yourself in the cloud. It's a pretty large barrier to entry if companies are supposed to hire or train employees to become Hyperledger production operations gurus. That doesn't happen with the more traditional data storage technologies. If I want to stand up my own production worthy MySql or Cassandra cluster, I don't take two years off to study the source code. I sign a Percona or Datastax support contract. Those two companies have a lot of impeccable reputation that you could safely bet on. What companies could I engage with that would give me that same piece of mind with running production worthy Fabric? Care to name some names?
• ##### Re: Cloud Restrictions Clarification
by Baiju Jacob /
Your message is awaiting moderation. Thank you for participating in the discussion.
Hello Glenn,
My point was to clarify that there is no need to wait for cloud providers to set up the network if an enterprise wants to. What the cloud providers provide today is a fabric template on top of an ubuntu/linux instance.They dont change any source code. You can have the same with any cloud of your choice. The source is the same which is open to all like any Linux offering. Enterprises have been doing this for many years either with their inhouse team or with their System integrators. Cloud subscription model is a new option which has come up in the last five years. For smaller organisations or those who dont have SIs/in house expertise you can check out CDPaaS offering from ChainDigit (www.chaindigit.com/CDPaaS).And the expertise required is basic system administration and operations expertise. All Fabric components run on docker containers. With most cloud providers unless you sign up for their services organisations still have to do it themselves (eg: who is permissioned into your network, deployment of smart contracts(chain code) relevant to your network etc.). We are building decentralised applications here. Forcing a decentralised consortium of organisation to one centralised cloud provider itself is contrary to the basic concepts of blockchain.
• ##### Re: Cloud Restrictions Clarification
Your message is awaiting moderation. Thank you for participating in the discussion.
I got a 404 on that chaindigit address. Good luck with your endeavors, Baiju. I mean no offense, sir, but I am beginning to suspect that you don't understand your target audience at Optum Government Solutions.
• ##### Re: Cloud Restrictions Clarification
by Baiju Jacob /
Your message is awaiting moderation. Thank you for participating in the discussion.
Sorry! Didnt see this reply I should not have used Capitals it should have been cdpaas. No offense to you as well, but equating Composer ( a tool similar to Truffle) to Hyperledger Fabric which is equivalent of Ethereum did not seem fair. Having worked in Hyperledger Fabric for more than 15 months it is important to clear misconceptions. As you may have heard Walmart has asked its suppliers to be on its network based on Hyperledger Fabric by 2019. Oracle and SAP is also using Fabric as the foundation for Their BaaS, not to mention IBM Bluemix BaaS which is based on Fabric. If none of them understand it, probably I dont either :)
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https://forums.roguetemple.com/index.php?topic=18.msg37281 | ### Author Topic: The Codex of The Temple - Rules of Behaviour (Read 67520 times)
#### Slash
• Priest of Roguetemple
• Rogueliker
• Posts: 1175
• Karma: +4/-1
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #15 on: May 16, 2014, 08:52:22 PM »
I think this is covered by rule 1.2; everybody is entitled to have their own opinions, but should express them in a respectful way.
In no case should your opinions posted in this forum make people feel uncomfortable (that's what we mean with "bashing people"); more so, if they explicitly state it's happening and other members of the community express this concern.
There are no "right" opinions, but this is not a place to discuss that; all the Codex seeks is to maintain the harmony of this place and prevent discussion from being ruined with inappropriate participation. That should not be tolerated.
#### Krice
• (Banned)
• Rogueliker
• Posts: 2316
• Karma: +0/-2
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #16 on: May 19, 2014, 06:13:35 AM »
In fact I don't know what Darren is referring when he takes me as an example, but it doesn't feel nice to be a target of such attack.
#### Darren Grey
• Rogueliker
• Posts: 2001
• Karma: +0/-0
• It is pitch black. You are likely to eat someone.
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #17 on: May 19, 2014, 10:08:49 PM »
#### guest509
• Guest
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #18 on: May 20, 2014, 06:39:41 PM »
http://forums.roguetemple.com/index.php?topic=4131.0
http://forums.roguetemple.com/index.php?topic=3822.0
Lol. You responded to one of the most ridiculous "I'm innocent" pleas I've ever seen. I'm honestly laughing out loud right now. LOUDLY.
To be clear, tolerance means not tolerating intolerance.
#### Krice
• (Banned)
• Rogueliker
• Posts: 2316
• Karma: +0/-2
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #19 on: May 20, 2014, 08:17:33 PM »
Both "booth babes" and "girl gamers" issues are perfectly valid. If we ban booth babes what comes next? Do women have to wear burkha? And "girl gamers" then.. don't even ask. I'm just saying that you can totally ignore the reality, but it's not what all people do. It's more like american way to look at things, or not to look.
#### Rickton
• Rogueliker
• Posts: 215
• Karma: +0/-0
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #20 on: May 20, 2014, 10:54:46 PM »
Creator of the 7DRL Possession: Escape from the Nether Regions
And its sequel, simply titled Possession
#### guest509
• Guest
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #21 on: May 21, 2014, 02:19:40 AM »
Both "booth babes" and "girl gamers" issues are perfectly valid. If we ban booth babes what comes next? Do women have to wear burkha? And "girl gamers" then.. don't even ask. I'm just saying that you can totally ignore the reality, but it's not what all people do. It's more like american way to look at things, or not to look.
Krice the martyr.
#### TheCreator
• Rogueliker
• Posts: 370
• Karma: +0/-0
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #22 on: May 21, 2014, 05:42:37 AM »
To be clear, tolerance means not tolerating intolerance.
Isn't it just a clever way of saying "my view is better than yours"?
Fame (Untitled) - my game. Everything is a roguelike.
#### AgingMinotaur
• Rogueliker
• Posts: 802
• Karma: +2/-0
• Original Discriminating Buffalo Man
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #23 on: May 21, 2014, 07:24:19 AM »
To be clear, tolerance means not tolerating intolerance.
Isn't it just a clever way of saying "my view is better than yours"?
No.
As always,
Minotauros
PS. We did it again – turned even this sticky thread about the Codex into a trollhouse. Huzzah!
« Last Edit: May 21, 2014, 07:27:12 AM by AgingMinotaur »
This matir, as laborintus, Dedalus hous, hath many halkes and hurnes ... wyndynges and wrynkelynges.
#### Darren Grey
• Rogueliker
• Posts: 2001
• Karma: +0/-0
• It is pitch black. You are likely to eat someone.
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #24 on: May 21, 2014, 12:15:00 PM »
Better example: http://forums.roguetemple.com/index.php?topic=4007.msg36422#msg36422
Ugh, I didn't even see that one.
Is it too much to ask to ban sexism from the forums? Or must we wait till Krice starts saying black people are terrible at roguelikes?
#### Quendus
• Rogueliker
• Posts: 447
• Karma: +0/-0
• $@ \in \{1,W\} \times \{1,H\}$
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #25 on: May 21, 2014, 05:31:22 PM »
While you're at it, why not warn Krice not to stuff beans up his nose?
#### awake
• Newcomer
• Posts: 43
• Karma: +0/-0
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #26 on: May 21, 2014, 07:06:38 PM »
Is it too much to ask to ban sexism from the forums?
I sure as hell hope so.
#### mushroom patch
• Rogueliker
• Posts: 554
• Karma: +0/-0
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #27 on: May 21, 2014, 08:00:01 PM »
I think such rule changes ought to be instituted. I am eager to see the resulting avalanche of pent up participation from the reticent multitudes put off by Krice's comments.
#### AgingMinotaur
• Rogueliker
• Posts: 802
• Karma: +2/-0
• Original Discriminating Buffalo Man
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #28 on: May 22, 2014, 07:48:27 AM »
Very funny, shroomie Truth is, I've on several occations received PMs by users who after some weeks or months just quit because they can't be bothered with all that bovine dejecture. But I'm principally in agreement with Slash in this matter, and hoping the community itself is able to keep the discussions at a certain level. If not, I can always just pack my shit and leave myself. Yet, to all you stark defenders of "free speech", if you're having a party and one guest is harassing another for being black/gay/a woman/jew/whatever – are you seriously telling me that it's the victim of abuse you'd show the door?
As always,
Minotauros
This matir, as laborintus, Dedalus hous, hath many halkes and hurnes ... wyndynges and wrynkelynges.
#### mushroom patch
• Rogueliker
• Posts: 554
• Karma: +0/-0
##### Re: The Codex of The Temple - Rules of Behaviour
« Reply #29 on: May 22, 2014, 12:05:17 PM »
Very funny, shroomie Truth is, I've on several occations received PMs by users who after some weeks or months just quit because they can't be bothered with all that bovine dejecture. But I'm principally in agreement with Slash in this matter, and hoping the community itself is able to keep the discussions at a certain level. If not, I can always just pack my shit and leave myself. Yet, to all you stark defenders of "free speech", if you're having a party and one guest is harassing another for being black/gay/a woman/jew/whatever – are you seriously telling me that it's the victim of abuse you'd show the door?
As always,
Minotauros
I'm no free speech booster and I agree that it's important to keep things reasonably civil and inoffensive to normal sensibilities. I'm just responding to the implication that low volume outside of announcements is the result of not-very-aggressive trolling/obnoxiousness from Krice as opposed to more mundane factors. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5322163701057434, "perplexity": 12117.31199237644}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487586239.2/warc/CC-MAIN-20210612162957-20210612192957-00027.warc.gz"} |
http://tex.stackexchange.com/questions/82612/improving-the-pov-definition-in-the-listings-package | # Improving the POV definition in the listings package
I'm attempting to create a language definition in the listings package that mimics exactly the syntax highlighting in POV-Ray 3.6 for Windows (http://www.povray.org/download/). Here is a screenshot from POV, which I'm trying to imitate:
(The POV language definition in the listings package is not the same.)
I include below my attempt so far, but it has some flaws. First, I cannot get it to make numbers green, despite my attempt. Second, I cannot get it to make angle brackets (or other operators) red, despite my attempts. By contrast, my attempt to get curly braces to show up blue works fine, despite its similarity to the angle brackets problem/solution. I am obviously doing something wrong, but reading the reference manual for the listings package didn't clear up my confusion.
Here's an example of my wrong results:
Any tips?
\documentclass[12pt]{article}
\usepackage{listings}
\usepackage{color}
\definecolor{povcodered}{rgb}{0.75,0.25,0.25}
\definecolor{povcodegreen}{rgb}{0.25,0.75,0.25}
\definecolor{povcodeblue}{rgb}{0.25,0.25,0.75}
\definecolor{povcodepurple}{rgb}{0.5,0,0.35}
\definecolor{povcodebluegreen}{rgb}{0,0.5,0.5}
\lstdefinelanguage{myPOV}{
alsoletter={\#\{\}\<\>},
keywords={
sphere, cone, and, so, on,
\#include, \#declare, \#version},
keywords={[2]\{,\}},
keywords={[3]\<,\>},
sensitive=true,
string=[b]{"},
comment=[l]{//},
morecomment=[s]{/*}{*/}}
\lstset{language=myPOV,
basicstyle=\ttfamily\bfseries,
keywordstyle=\color{povcodepurple},
keywordstyle=[2]\color{povcodeblue},
keywordstyle=[3]\color{povcodered},
stringstyle=\color{povcodered},
numberstyle=\color{povcodebluegreen}}
\begin{document}
\begin{lstlisting}
#include "somefile.inc"
// now let's add a shape
sphere {
<0,0,0>, 1
translate <5,3,2>
}
\end{lstlisting}
\end{document}
-
Welcome to TeX.sx! Usually, we don't put a greeting or a "thank you" in our posts. While this might seem strange at first, it is not a sign of lack of politeness, but rather part of our trying to keep everything very concise. Upvoting is the preferred way here to say "thank you" to users who helped you. – Kurt Nov 13 '12 at 19:25
While code snippets are useful in explanations, it is always best to compose a fully compilable MWE that illustrates the problem including the \documentclass and the appropriate packages so that those trying to help don't have to recreate it. While solving problems is fun, setting them up is not. Then those trying to help can simply cut and paste your MWE and get started on solving problem. – Peter Grill Nov 13 '12 at 19:33
Also, please use a supported image format, and provide the correct and incorrect image for the same code snippet so it is easier to compare (and include the code snippet in your MWE). You should edit your question and upload the pictures using the picture icon button, and remove the !. Then other higher rep users here can simply remove the ! and you image will show up. – Peter Grill Nov 13 '12 at 19:38
I've made edits in accordance with these directions. Feel free to put the exclamation points back in. Thanks! – Nathan Nov 14 '12 at 16:12
I think I've mostly answered my own question. By reading some of the other related questions I cobbled together the following POV language definition file that does most of what I want, or at least is extensible enough that it will be able to do most of what I want after it's done evolving.
The essential fix was to use literate in a way that's not really its intended use, but just as a generic mechanism for replacing any character sequence with any other. This allows me to choose specific digits, operators, etc., and assign them colors.
Here is POV code that isn't fully complete (not all operators and keywords) but I'll extend it as I hit new operators and keywords that aren't on this list. You get the idea. The code is below.
The one thing that isn't yet solved by this is that the double-slash for a one-line comment is now treated like two adjacent single-slashes, so there is no such thing as a one-line comment anymore. It seems that literate overrides everything else. That question therefore remains.
\lstdefinelanguage{myPOV}{
alsoletter={\#\{\}},
keywords={
sphere, cone, cylinder, box, object,
rotate, translate, scale, matrix,
camera, location, direction, right, look_at,
x, y, z, pow, function,
global_settings, assumed_gamma,
\#include, \#declare, \#version},
keywords={[2]\{,\}},
sensitive=true,
string=[b]{"},
comment=[l]{//},
morecomment=[s]{/*}{*/},
literate=%
*{0}{{{\color{povcodebluegreen}0}}}1
{1}{{{\color{povcodebluegreen}1}}}1
{2}{{{\color{povcodebluegreen}2}}}1
{3}{{{\color{povcodebluegreen}3}}}1
{4}{{{\color{povcodebluegreen}4}}}1
{5}{{{\color{povcodebluegreen}5}}}1
{6}{{{\color{povcodebluegreen}6}}}1
{7}{{{\color{povcodebluegreen}7}}}1
{8}{{{\color{povcodebluegreen}8}}}1
{9}{{{\color{povcodebluegreen}9}}}1
{+}{{{\color{povcodered}+}}}1
{-}{{{\color{povcodered}-}}}1
{*}{{{\color{povcodered}*}}}1
{/}{{{\color{povcodered}/}}}1
{<}{{{\color{povcodered}<}}}1
{>}{{{\color{povcodered}>}}}1}
\lstset{language=myPOV, frame=single,
basicstyle=\ttfamily\bfseries,
keywordstyle=\color{povcodepurple},
keywordstyle=[2]\color{povcodeblue},
stringstyle=\color{povcodered},
framextopmargin=3mm,
framexbottommargin=3mm
}
-
Move the definition of comment=[l]{//} behind the assignment of {/}{{{\color{povcodered}/}}}1, i.e. move it behind all literate assignments. A similar case can be found somewhere in the listings documentation. – Speravir Nov 20 '12 at 21:32
@Speravir: This did not make a difference. The literate assignments, even if they are put before the comment= lines, seem to take precedence over them. – Nathan Nov 21 '12 at 14:20
Aah, I forgot, that the comment sign itself is not in markup. But you could include a second literate entry behind the existing one with {//}{{<your wanted formatting>}}2, see in the manual under “Literate Programming”. BTW according to this you have one too many pair of braces in each of your entries. And add this into the answer! – Speravir Nov 21 '12 at 18:22
And: What I’ve overread in the manual until now: “The optional star indicates that literate replacements should not be made in strings, comments, and other delimited text.”, a reminder there would be useful, that this does not apply to the comment/string/delimiter signs themselves (--> kind of bug report). – Speravir Nov 21 '12 at 18:27 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6846750974655151, "perplexity": 1612.5182868986358}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-48/segments/1386163956743/warc/CC-MAIN-20131204133236-00097-ip-10-33-133-15.ec2.internal.warc.gz"} |
https://math.stackexchange.com/questions/2251090/galois-group-of-an-irreducible-separable-polynomial-be-abelian-then-each-of | # Galois group of an irreducible , separable polynomial be abelian , then each of the roots of the polynomial generates the splitting field?
Let $f(x)\in k[x]$ be an irreducible , separable polynomial , let $E$ be the splitting field of $f(x)$ , then $E/k$ is a Galois extension . If $Gal(E/k)$ is abelian then is it true that $E=k(a)$ for every root $a$ of $f(x)$ ?
My Attempt : As $G:=Gal(E/k)$ is normal so for any root $a$ of $f(x)$ , $k(a)$ is Galois over $k$ , then if $H:=Gal(E/k(a))$ then $|H|=[E:k(a)]$ and $[G:H]=Gal(k(a)/k)=[k(a):k]=n$ . Also , as $n:=\deg f =[k(a):k]|[E:k]=|G|$ , and $G$ is abelian , so $G$ has a subgroup $K$ of order $n$ , let $F$ be the fixed field of $H$ , then $E/F$ and $F/k$ are Galois and $[E:F]=|K|=n$ . But this is not leading anywhere .
• @GalPorat : what definition ? do you mean we don't need the automorphism group to be abelian etc. ? – user228169 Apr 25 '17 at 8:08
• Related 1, 2 – Jyrki Lahtonen Apr 25 '17 at 10:25
The proof goes as follows:
Since $\operatorname{Gal}(E/k)$ is abelian, any subgroup is normal, hence any intermediate field of $E/k$ is normal. In particular $k(a)/k$ is normal and by the definition of a normal extension, it follows that all roots of $f$ are contained in $k(a)$. Hence $E=k(a)$.
• Ah yes ! Thanks a lot – user228169 Apr 25 '17 at 8:27
• Short and to the point. Nice. +1 – DonAntonio Apr 25 '17 at 8:41
Since $f$ is irreducible, the Galois group is transitive on the roots.
In a transitive commutative permutation group, for any $x$, $Stab_G(x) = \{id\}$ :
Let $x$ be a root. if some element $g$ fixes $x$ and $y$ is another root, then there is an $h$ such that $h(x)=y$ and so $g(y) = gh(x) = hg(x) = h(x) = y$. Therefore if $g$ fixes $x$, it fixes every root, and so $g$ must be the identity.
This shows that $k(x) = E^{Stab_G(x)} = E^{\{id\}} = E$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.994854211807251, "perplexity": 118.73552337817293}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027317817.76/warc/CC-MAIN-20190823020039-20190823042039-00077.warc.gz"} |
https://math.stackexchange.com/questions/1490120/let-a-be-a-bounded-open-set-in-mathbbrn-give-an-example-where-int-b | Let $A$ be a bounded open set in $\mathbb{R}^n$. Give an example where $\int_{\bar{A}} f$ exists but $\int_A f$ does not.
Integration in the Riemann sense.
Let $A$ be a bounded open set in $\mathbb{R}^n$; let $f: \mathbb{R}^n\to \mathbb{R}$ be a bounded continuous function. Give an example where $\int_{\bar{A}} f$ exists but $\int_A f$ does not.
I cannot think of any such example. I would greatly appreciate it if anyone can provide me with some insight.
• In which sense are you defining integration, Lebesgue or Riemann? In the Lebesgue sense this result is nonsensical, since $f 1_A$ will necessarily also be integrable if $f$ is. – Ian Oct 21 '15 at 2:59
• Sorry should've made it clear, I mean Riemann. – nomadicmathematician Oct 21 '15 at 3:14
• @Ian: this might be silly, but is it obvious that $1_A$ is measurable if $1_{\overline{A}}$ is? – Giovanni Oct 21 '15 at 3:14
• @Giovanni $A$ is open and $\overline{A}$ is closed, so the indicator functions are definitely measurable. – Ian Oct 21 '15 at 3:15
• @takecare How do you define Riemann integration on an open set? (All notions of Riemann integration that I understand depend on compactness.) – Ian Oct 21 '15 at 3:16
I don't think this statement makes sense as formulated. In particular, if $f$ is integrable on $\overline{A}$, then its set of discontinuity points has measure zero. The restriction of $f$ to $A$ will not add any discontinuity points (because it can be given by the composition of $f$ with the inclusion map, and the inclusion map is continuous). So the set of discontinuity points of the restriction will also have measure zero, so $f$ will be integrable on $A$ as well (if that notion even makes sense in the Riemann setting).
A reformulation (assuming we've somehow sensibly defined Riemann integration on an open set) is as follows. Let $C$ be a fat Cantor set, let $A=[0,1] \setminus C$, and then consider $f=1_A$. Then $f$ is actually continuous on $A$, because it is constant there. But no matter what, $f$ cannot be Riemann integrable on $\overline{A}$, because its set of discontinuity points is $C$ which has positive measure.
• I don't really understand your example. $f$ is supposed to be continuous on $\mathbb R^n$, not only on $A$. Beside $f$ is supposed to be integrable on $\bar A$. – user251257 Oct 21 '15 at 4:00
• @user251257 I agree, I had to change some of the original hypotheses somewhat because as formulated they do not make sense. In particular, if $f$ is integrable on $\overline{A}$, then no discontinuities are introduced by restricting to $A$, so by the Lebesgue criterion, $f$ is also integrable on $A$ (whatever that even means in the Riemann case). – Ian Oct 21 '15 at 4:21
• @user251257 Er, what? $A$ is a bounded open set. $f=1$ will be integrable on both $\overline{A}$ and $A$. There is no way to satisfy the OP's condition by having the integrals blow up. – Ian Oct 21 '15 at 4:33 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9781813025474548, "perplexity": 142.47484331995554}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986648481.7/warc/CC-MAIN-20191014003258-20191014030258-00045.warc.gz"} |
https://aviation.stackexchange.com/questions/30149/what-is-the-height-requirement-for-pilots-in-the-philippines | # What is the height requirement for pilots in the Philippines?
I am not an airline pilot nor do I work in the industry but I'm looking forward to. I live in the Philippines, a part of South East Asia.
My question is: what is the current minimum height requirement in the Philippines to be a private airline or commercial airline pilot?
I was at a Aviation School seminar a few months ago and one of the guest asked the host if height still mattered and the host answered "not anymore because airplane pilot seats are now adjustable". That didn't really convince me because they might be biased considering they are looking for students.
• I am roughly about 5'3". – majidarif Jul 19 '16 at 12:44
• welcome to aviation.SE. The current requirement is on topic, but how you'd project the requirement will change in the future is not (we don't do speculation here). Are you interested in the requirement in the Philippines or somewhere else? – Federico Jul 19 '16 at 12:49
• @Federico Thank you. I am interested in the requirement in the Philippines. :) – majidarif Jul 19 '16 at 12:50 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2182450145483017, "perplexity": 1367.8088316171006}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347410535.45/warc/CC-MAIN-20200530231809-20200531021809-00055.warc.gz"} |
http://mathhelpforum.com/calculus/208033-rc-circuit.html | # Math Help - RC-Circuit
1. ## RC-Circuit
a) The current in a wire is defined as the derivative of the charge: I(t)=Q'(t). The quantity of charge Q in coulombs (C) that has passed through a point in a wire up to time t (measured in seconds) is given by Q(t)=Qmax(1-(e^((-1/RC)t))). At what time is the charge the maximum charge, Qmax? At what time is the charge minimum? Determine limQ(t).
2. ## Re: RC-Circuit
To find when $Q(t)=Q_{\text{max}}$, we may set:
$Q_{\text{max}}=Q_{\text{max}}\left(1-e^{-\frac{1}{RC}t} \right)$
Now, solve for $t$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 3, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9260697960853577, "perplexity": 1243.6821363089464}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1412037663467.44/warc/CC-MAIN-20140930004103-00041-ip-10-234-18-248.ec2.internal.warc.gz"} |
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## anonymous one year ago Can someone please help me step by step with this problem? x^(-2/3) (2-x)^2 - 6x^1/3 (2-x) Delete Cancel Submit
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• one year ago
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Without knowing exactly what you're trying to do, we can't help much. I'd guess you're wanting to simplify the given expression. $x^{-2/3}(2-x)^2-6x^{1/3}(2-x)$ For starters, there's a common factor of $$2-x$$, so let's pull that out: $(2-x)\left[x^{-2/3}(2-x)-6x^{1/3}\right]$ Next, notice that $$-\dfrac{2}{3}=-\dfrac{3}{3}+\dfrac{1}{3}$$. Since $$x^{a+b}=x^ax^b$$, this means that $$x^{-2/3}=x^{-3/3}x^{1/3}=x^{-1}x^{1/3}$$, and so the two bracketed terms share another common factor of $$x^{1/3}$$. Pulling that out gives $x^{1/3}(2-x)\left[x^{-1}(2-x)-6\right]$ What else can you do?
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Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9746406674385071, "perplexity": 2254.3483714398035}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560279915.8/warc/CC-MAIN-20170116095119-00020-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://community.wolfram.com/groups/-/m/t/1150253 | # [✓] Solve and Plot numerically this differential equation?
GROUPS:
Consider the following code: e1 = 0.001; e^0.4 = {{2.37/de^0.06} - 1.6}/10 {1 - Log[de]/13.8}^0.7 the initial value is e1=0.001 for t0=1 and the time period is between {t,1,18000}
Gianluca Gorni 1 Vote Your equation is implicit in the derivative. We can work around the problem by taking the derivative of the equation, which makes it explicit in the second derivative. If I don't misunderstand your syntax, here is an attempt: eq = e[t]^(4/10) == (((237/100)/e'[t]^ (6/100)) - 16/10)/(10 (1 - Log[e'[t]]/(138/10))^(7/100)) deq = Simplify@D[eq, t] de1 = e'[1] /. Solve[eq /. {t -> 1} /. e[1] -> 1/1000, e'[1], Reals][[1]] // N sol = NDSolveValue[{deq, e[1] == 1/1000, e'[1] == de1}, e, {t, 1, 18000}] Plot[sol[t], {t, 1, 18000}] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5334014296531677, "perplexity": 8430.418722004068}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187824537.24/warc/CC-MAIN-20171021005202-20171021025202-00685.warc.gz"} |
http://wrack.wikia.com/wiki/Heavy_armour | ## FANDOM
88 Pages
The heavy armour gives the player maximum armour. To calculate your max armour use the following formula:
$maxarmour = 100 + (N * 5)$
N is the amount of max armour bonuses picked up by the player. Attempting to pick up heavy armour at max armour is impossible. Max armour is capped at 250. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 1, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3751693069934845, "perplexity": 9960.36925212363}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549426086.44/warc/CC-MAIN-20170726082204-20170726102204-00059.warc.gz"} |
https://ntnuopen.ntnu.no/ntnu-xmlui/handle/11250/227501/browse?type=subject&value=angular+momentum | Now showing items 1-1 of 1
• #### Different solutions in generation of angular momentum during imitation jump take-offs among diverse level ski jumpers
(Master thesis, 2017)
Introduction: During the push-off motion in ski jumping, the athlete strives to generate both a high vertical velocity and a correct angular momentum. The latter is important as it brings the athlete into the flight position. ... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8723161816596985, "perplexity": 3735.166146301258}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487641593.43/warc/CC-MAIN-20210618200114-20210618230114-00620.warc.gz"} |
http://mathhelpforum.com/trigonometry/213121-compound-angles-help-print.html | # Compound angles HELP!
• Feb 14th 2013, 03:33 PM
Kosky1
Compound angles HELP!
Hi I'm new to this, I've been given a question on compound angles and I really don't know how to go about it. Any help would be greatly appreciated:
Using compound angles prove that Cos(y-pi)+Sin(y+pi/2)=0
thanks Shaun
• Feb 14th 2013, 04:25 PM
Soroban
Re: Compound angles HELP!
Hello, Shaun!
You are expected to know these Compound Angle Identities:
. . $\sin(A \pm B) \:=\:\sin A\cos B \pm \cos A\sin B$
. . $\cos(A \pm B) \:=\:\cos A\cos B \mp \sin A\sin V$
Quote:
Using compound angles prove that: . $\cos(x-\pi)+\sin(x+\tfrac{\pi}{2})\:=\:0$
We have: . $\cos(x - \pi) \:=\:\cos(x)\cos(\pi) + \sin(x)\sin(\pi)$
. . . . . . . . . . . . . . . . $=\;\cos(x)\!\cdot\!(\text{-}1) + \sin(x)\!\cdot\!(0)$
. . . . . . . . . . . . . . . . $=\;\text{-}\cos(x)$
We have: . $\sin(x +\tfrac{\pi}{2}) \;=\;\sin(x)\cos(\tfrac{\pi}{2}) + \cos(x)\sin(\tfrac{\pi}{2})$
. . . . . . . . . . . . . . . . $=\;\sin(x)\!\cdot\!(0) + \cos(x)\!\cdot\!(1)$
. . . . . . . . . . . . . . . . $=\;\cos(x)$
Therefore: . $\cos(x-\pi) + \sin(x + \tfrac{\pi}{2}) \;=\;\text{-}\cos(x) + \cos(x) \;=\;0$
• Feb 14th 2013, 04:47 PM
Kosky1
Re: Compound angles HELP!
Ah thankyou. I had those identities right infront of me! Had a complete mind block
Thank you ever so much! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 10, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9494987726211548, "perplexity": 250.6848537153191}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320206.44/warc/CC-MAIN-20170623235306-20170624015306-00295.warc.gz"} |
https://economics.stackexchange.com/questions/3373/help-improving-this-definition-of-a-game | # Help improving this definition of a “game”?
My professor defined a game as follows:
• a set of $n$ players
• a set of strategies $s_i$ for each player $i$
• a set of payoffs $p_i$ for each player $i$
• turn-taking: sequential or simultaneous
• repetition: $k$ rounds, where $k\geq1$ and $k \in \Bbb{N}$
I have three problems with this definition:
1. He didn't define turn-taking mathematically, so I feel like it's a vague definition. There should be like an index of possible turns with max value $n$. But I'm not sure how to write it formally.
2. He doesn't define how we map from strategies selected to payoffs. Presumably, the set of payoffs should include a value for every possible combination of strategies selected. But there should be a way to state this formally as well.
3. He doesn't define what a strategy is. I suppose one could simply say that a strategy is the object we map from in the domain to an element in the set of payoffs (ie codomain). In that sense, anything that can be valued is a strategy, ie a possible action.
My Question:
Can someone offer a more complete definition than the one given? Specifically make sure it improves upon the concerns I mentioned.
• You can try one of many textbooks, there is one by Fudenberg and Tirole (not my personal choice), Myerson, and many others. You can find Osborne and Rubinstein online here: books.osborne.economics.utoronto.ca – usul Feb 17 '15 at 17:12
• Great, that's even better. I didn't know where to look. Thanks. – Stan Shunpike Feb 17 '15 at 17:27
• The definition of a game varies depending on the kind of game in question, e.g. extensive vs normal form, complete vs incomplete information, etc. Besides Osborne-Rubinstein, I'd also recommend Mas-Colell, Whinston, & Green (aka MWE). – Herr K. Feb 18 '15 at 20:11
Any game can be thought of as a tree (i.e. a non-cyclic graph). So to answer your first point about turn-taking, you might think about a function which maps nodes of the tree to some $i\in\{1,2,...n\}$ In the picture below, you might be able to define a formula to characterize the turn taking, but you can't necessarily do this in general. In this example $P_1$ and $P_2$ take alternating sequential turns. $P_1$ can choose $L$ or $R$, then $P_2$ can see which he chose, and then also choose $L$ or $R$.
Before going on to your second point, I need to take a moment to define information sets, which it doesn't sound like you've gotten to yet. Colloquially, an infoset is a set of vertices that represent uncertainty. The root of a game tree is always a singleton infoset, for example. Consider the game where you and I simultaneously choose heads or tails. When $P_2$ chooses whether or not to play heads or tails, she doesn't know if I have chosen to play heads or tails either. Thus while the game tree will have 3 internal vertices (1 that is the root for $P_1$, and 2 for $P_2$, reflecting $P_1$'s choice) there will only be 2 infosets because both vertices for $P_2$ will be contained in the same infoset. In games where turn-taking is sequential, all infosets should be singleton.
Now back to your question about strategies. Each player has a set of strategies. In the example tree provided above $S_1 = \{LLLLL,LLLLR,...,RRRRR\}$. This might seem a little bit confusing at first as it seems like each element of $S_1$ goes above and beyond defining a path. Each player's strategy is defined in terms of infosets. Therefore, the element $LLLLL$ should be read as, when $P_1$ finds herself at the top, she will choose $L$, and when she finds herself at the vertex that is farthest on the left and 1 down from the top, she will also choose $L$. It then also says that if $P_2$ were to choose $R$ instead, that $P_1$ would choose $L$. Thus a strategy is the set of all possible actions a player might take under all possible contingencies.
Finally, how do we state the mapping from strategies to payoffs? First we note that ever player has a strategy set $S_i$, and then form the cartesian product $S=S_1 \times S_2 \times ... \times S_n$, which characterizes all possible strategy combinations for all possible players. Then our payoff will be $\pi:S\to\mathbb{R}^n$. In our example $\pi(LLLLL,LLLLLLLLLL) = (4,2)$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7514858245849609, "perplexity": 435.8474831136807}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987836368.96/warc/CC-MAIN-20191023225038-20191024012538-00453.warc.gz"} |
http://math.stackexchange.com/questions/76985/checking-the-binary-relations-symmetric-antisymmetric-and-etc | # Checking the binary relations, symmetric, antisymmetric and etc
this is my first post. My homework was to check each of tables and findout they are reflexive, symmetric, antisymmetric and transitional.
I would appreciate your help. I need someone to check my results. I really don't know why I do what I do. Especially while antysymmetric and transitional.
1: reflexive:yes, symmetric:no, antisymmetric:yes and transitional:yes
2: reflexive:yes, symmetric:yes, antisymmetric:no and transitional:yes
3: reflexive:no, symmetric:yes, antisymmetric:no and transitional:no
4: reflexive:yes, symmetric:no, antisymmetric:yes and transitional:yes
5: reflexive:yes, symmetric:no, antisymmetric:yes and transitional:no
I read all infos about that relations but it is hard for me. So what's the story. If I need find out antisymmetric case I need find at least one exception? Should I do the same also with transitional?
-
if anyone can edit my post, please insert/correct image :) – CrystalCrystalNYPD Oct 29 '11 at 19:21
I believe you mean "transitive", not "transitional". – Austin Mohr Oct 29 '11 at 19:59
yes, transitive. I haven't wrote Math problems in English :) It should be transitive but i can not change due low level and the image will disapear :O – CrystalCrystalNYPD Oct 29 '11 at 20:41
Reflexive: there are no zeros on the diagonal.
Symmetric: the table has to be symmertic.
Antisymmetric: if you reflect the table with the diagonal (I mean a mirror symetry, where the diagonal is the mirror), then 1 goes to 0 (but 0 can go to 0).
Transitive: I can't think of any smart method of checking that. You just check if the relation is transitive, so you take element#1 (and then all the rest) and look at all the ones in the row (probably in the row, but it's a matter of signs): if there is one in a column with - say - number #3 (you have to check all the 1s), you look at the row#3 and check if for every 1 in this row, there is 1 in the row#1 - it is one eye-sight, so it is not that bad.
If you want to say 'yes', you have to check everything. But if while checking you find that something is 'wrong', then you just say 'no', because one exception is absolutely enough. There is no such thing like 'yes but...' in mathematics :)
You are wrong about antisymmetric: it does not mean 'asymmetric'. It means that if there is (1,5) in the relation, then (5,1) is not. Reflexive and symmetric are OK. I'm too lazy to check the last part.
-
You are correct about reflexivity and symmetry. The main diagonal is all $1$’s, so the relation is reflexive, and the matrix is symmetric about the main diagonal, so the relation is symmetric.
A relation $R$ is antisymmetric if $$(a R b\text{ AND }bRa)\implies (a=b)\;.$$ For your first relation you have $1R3$ and $3R1$, and yet $3\ne 1$, so this relation is not antisymmetric. For the same reason the second and fourth relations are not antisymmetric. The third relation is not antisymmetric because $1R5$ and $5R1$, even though $1 \ne 5$. The fifth is not antisymmetric because $2R5$ and $5R2$, even though $2 \ne 5$. Thus, none of the relations is antisymmetric. The visual test is to see whether there is a pair of $1$’s that are symmetric with respect to the main diagonal; if there are $-$ and we found such a pair of every one of these five relations $-$ then the relation is not antisymmetric.
There is no simple test for transitivity. For the first relation, note that $2R3$ and $3R1$, but it’s not true that $2R1$, so the first relation is not transitive. In the third relation $1R4$ and $4R2$, but it’s not true that $1R2$, so the relation is not transitive. In the fourth relation $2R3$ and $3R1$, but it isn’t true that $2R1$, so the relation is not transitive. In the last relation $3R2$ and $2R1$, but it’s not the case that $3R1$, so the relation is not transitive.
The second relation is, as you say, transitive. One way to demonstrate this is to notice that in this relation every odd number in $\{1,2,3,4,5\}$ is related to every odd number, and every even number to every even number, but no odd number is related to any even number or vice versa. Thus, if $aRb$ and $bRc$, then either $a,b$, and $c$ are all odd, or they’re all even, and in either case it’s true that $aRc$.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9553759694099426, "perplexity": 269.1016097081878}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701150206.8/warc/CC-MAIN-20160205193910-00019-ip-10-236-182-209.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/kruskal-szekeres-coordinates.239378/ | # Kruskal-Szekeres coordinates
1. Jun 8, 2008
### stevebd1
I'm currently looking at Kruskal-Szekeres coordinates in relation to a static black hole.
For the exterior region, the coordinates are-
$$R=\left(\frac{r}{2GM}-1\right)^{1/2}e^{r/4GM}cosh\left(\frac{t}{4GM}\right)$$
For the interior-
$$R=\left(1-\frac{r}{2GM}\right)^{1/2}e^{r/4GM}sinh\left(\frac{t}{4GM}\right)$$
where c = 1 and G, the gravitational constant, is kept explicit.
I've looked extensively on the web but can find very little as to explaining the equations in a bit more depth. I'd appreciate it if someone could shed some light on what e represents and while I'm certain that c^2 appears adjacent to r in the first set of brackets, does it appear anywhere else in the equations? Also, would it be correct to assume that t represents time?
Last edited: Jun 8, 2008
2. Jun 9, 2008
### Wallace
Check out this site. It goes through the various co-ordinate representations of black holes and has some nice animations as well. I think it should answer your question.
3. Jun 11, 2008
### stevebd1
Thanks for the link Wallace. I also found a paper that covered the subject 'Kruskal Coordinates and Mass of Schwarzschild Black Holes by' Abhas Mitra-
http://arxiv.org/abs/astro-ph/9904162
Unfortunately, neither actually state what the quantities e and t are, I can only assume that e is energy and t is time but don't see how they would be incorporated into the equations. It appears to be taken for granted that e and t are understood but would appreciate confirmation as to what they are.
Last edited: Jun 11, 2008
4. Jun 11, 2008
### Wallace
t is time, though of course it is a different time co-ordinate to that appearing in the Schwarschild metric. I'm pretty sure that the e is just the constant (i.e. the same e as in Log_e = Ln).
5. Jun 11, 2008
### George Jones
Staff Emeritus
Careful; the main results of this infamous and unpublished paper are quite wrong.
6. Jun 12, 2008
### stevebd1
Thanks for the heads up George, I was under the impression that if a paper was on the arxiv website then it had passed some seal of approval, that doesn't appear to be the case; I'm assuming that Kruskal-Szekeres coordinates are still legite though. Regarding e being a constant and probably the log of something, what exactly would it be the log of?
7. Jun 12, 2008
### stevebd1
I twigged within a couple of minutes of my reply that e is a constant as stipulated in the wikipedia link; Physics Forums appears to undergo some kind of maintanence around 7.45 and 8.15 am GMT (which would be around midnight PDT) so I couldn't edit my post. Does anyone have an idea of how time would be incorporated as t?
Last edited: Jun 12, 2008
8. Mar 25, 2010
### saturn
hello, i would like to know what result in the paper is wrong? it is the transformation itself?
9. Mar 25, 2010
### Wallace
I haven't read that paper in detail, but from the abstract it is drawing physical significance from the properties of a particular co-ordinate system. This is a big no no! Anything with physical meaning will be invariant (not co-ordinate dependant). So for instance, you should be able to demonstrate what that paper claims to show in the Schwarschild co-ordinate system, or any other of the many BH co-ordinate charts.
10. Mar 25, 2010
### Wallace
I realise this is an old post, but since the thread has been bumped anyway...
The fact that a paper appears on arxiv really doesn't signify very much. It doesn't mean that it has been peer-reviewed. There is a level of moderation of arxiv postings, but it is not very strict. (That is in no way a criticism of arxiv, I'm just saying how it is).
More generally, even if something is peer-reviewed, that still doesn't mean that the contents of the paper are now considered to be the new standard. This is a very common misconception about peer review. The real peer review comes after a paper has been published and the whole community can read, respond, cite or ignore the paper depending upon the arguments it presents. The formal review process prior to a paper's publication simply ensures that the arguments are clear and free of obvious mistakes, any data are presented with sufficient detail to understand possible sources of error and that relevant prior work has been considered and responded to if necessary. A referee doesn't even have to agree with a paper's conclusions in order to pass it for publication.
Last edited: Mar 25, 2010
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https://lavelle.chem.ucla.edu/forum/search.php?author_id=10889&sr=posts | ## Search found 50 matches
Thu Mar 15, 2018 2:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram Question from Wednesday's (03/15/18) Lecture
Replies: 2
Views: 174
### Re: Cell Diagram Question from Wednesday's (03/15/18) Lecture
The line separates the electrode.
Thu Mar 15, 2018 2:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Coefficients when writing cell diagrams
Replies: 3
Views: 217
### Re: Coefficients when writing cell diagrams
No. Cell diagrams are simply a summary of the players in the redox reactions.
Thu Mar 15, 2018 2:00 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Water in Mechanism
Replies: 5
Views: 280
### Re: Water in Mechanism
If it is the solvent, then you can leave it out of the rate law. This is because solvents are present in such high concentrations that their concentrations don't change much during the reaction.
Sat Mar 10, 2018 7:46 pm
Forum: Balancing Redox Reactions
Topic: 14.5 Part a
Replies: 4
Views: 253
### Re: 14.5 Part a
If there are any H+ ions, you need to convert them to H2O using OH-.
Sat Mar 10, 2018 7:45 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Change in Enthalpy vs. Change in Entropy [ENDORSED]
Replies: 2
Views: 307
### Re: Change in Enthalpy vs. Change in Entropy[ENDORSED]
Enthalpy is a state property and entropy is not.
Sat Mar 10, 2018 7:38 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.49
Replies: 2
Views: 186
### Re: 8.49
Using the 8.314 results in the correct units.
Sun Mar 04, 2018 4:27 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: K'
Replies: 7
Views: 402
### Re: K'
You can also use the formulas given in the equations sheet. Just make sure you understand the formulas and which order reaction to use them for.
Sun Mar 04, 2018 4:26 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Independent of rate
Replies: 3
Views: 196
### Re: Independent of rate
The rate is independent of the concentration if the reaction is zero order with respect to that reactant.
Sun Mar 04, 2018 4:25 am
Forum: General Rate Laws
Topic: 15.13 part a?
Replies: 3
Views: 207
### Re: 15.13 part a?
The rate equals k(concentration of H2)(concentration of I2). It is, in a way, k(concentration)^2.
Sun Feb 25, 2018 4:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: reducing power?
Replies: 5
Views: 578
### Re: reducing power?
Reducing power is the ability of something to give up electrons so that those electrons can go reduce some other molecule.
Sun Feb 25, 2018 4:46 pm
Forum: General Rate Laws
Topic: rate of consumption sign
Replies: 2
Views: 171
### Re: rate of consumption sign
The terms themselves imply the sign. If you have a negative rate of consumption, you would be forming the molecule; it doesn't make sense to call it the rate of consumption. The same goes for rate of formation.
Sun Feb 25, 2018 4:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Strongly Reducing Metals
Replies: 5
Views: 269
### Re: Strongly Reducing Metals
The lower the standard reduction potential, the more unlikely the metal will get reduced (since more negative E values result in more positive G values).
Sun Feb 18, 2018 11:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.15.c
Replies: 2
Views: 170
### 14.15.c
For this question, the overall equation is given as Cd(s) + 2 Ni(OH)3(s) --> Cd(OH)2(s) + Ni(OH)2(s). However, in the cell diagram, there was a KOH. Where did the potassium come from?
Sun Feb 18, 2018 11:52 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.13 d
Replies: 1
Views: 173
### 14.13 d
What are the rules for balancing a redox equation with only one reactant/product? For example, the equation given in 14.13.d is Au+(aq) --> Au(s) + Au3+(aq). I thought Au+(aq) would be used in both half reactions but the solutions manual chose to use Au(s) for both reactions instead.
Sun Feb 18, 2018 11:42 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: G=-nFE
Replies: 3
Views: 255
### G=-nFE
Why is the "n" in this equation always positive even when there is a negative change in moles?
Wed Feb 07, 2018 10:54 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 9.51 [ENDORSED]
Replies: 3
Views: 339
### Re: 9.51[ENDORSED]
deltaG = deltaH - TdeltaS. If deltaG is negative, then the reaction is spontaneous. Since deltaH is negative, the reaction will be spontaneous for all positive values of deltaS and small negative values of deltaS.
Wed Feb 07, 2018 10:45 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 9.25
Replies: 2
Views: 158
### Re: 9.25
They are asking for molar entropy, so there are 6.02E23 molecules.
Wed Feb 07, 2018 10:37 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 9.25
Replies: 1
Views: 116
### Re: 9.25
The question asks for molar entropy, and there are 6.02E23 molecules. 6 orientations and 6.02E23 molecules results in 6^6.02E23. Plug it into the Boltzmann's equation and you will get the answer.
Sun Feb 04, 2018 8:13 pm
Forum: Phase Changes & Related Calculations
Topic: enthalpy and entropy when it comes to spontaneous reactions
Replies: 6
Views: 348
### Re: enthalpy and entropy when it comes to spontaneous reactions
It depends on the temperature.
Sun Feb 04, 2018 8:04 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 8.53
Replies: 2
Views: 121
### Re: 8.53
The problem gives all reactants and products. As for the phases, everything is in gas form at the given temperatures. Water can be liquid, but the problem specifies that the reaction uses water vapor.
Sat Feb 03, 2018 7:22 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Which value of R to use?
Replies: 3
Views: 167
### Re: Which value of R to use?
The method you mentioned should work as long as you make sure that you end up with the units that correspond to the variable you are solving for.
Fri Jan 26, 2018 4:41 pm
Forum: Phase Changes & Related Calculations
Topic: 8.41
Replies: 6
Views: 343
### Re: 8.41
Use the specific heat capacity of ice when you are raising the temperature of ice. Because the ice is already at 0C, you don't need to use the specific heat capacity of ice because the ice doesn't get warmer than 0C. Instead, use the heat of fusion to calculate the energy needed to melt the ice, the...
Fri Jan 26, 2018 4:29 pm
Forum: Phase Changes & Related Calculations
Topic: When to use Kelvin or Celsius
Replies: 10
Views: 1385
### Re: When to use Kelvin or Celsius
If the equation requires deltaT, then it doesn't matter whether you use K or C. If the equation requires T and not deltaT, then usually you will need to use K. Make sure to keep track of your units and that after cancelling, your ending units are actually what you are looking for.
Fri Jan 26, 2018 4:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Refresher on sig figs
Replies: 3
Views: 224
### Re: Refresher on sig figs
The values given in the appendix are accurate to the hundredths place. When you add them, your answer will still be accurate to the hundredths place. It happens that with the hundredths place, you will have 6 sig figs.
Sun Jan 21, 2018 1:56 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: change in internal energy
Replies: 4
Views: 190
### Re: change in internal energy
deltaU = q + w. When no work is done, U=q. When no heat is transferred, U=w.
Sun Jan 21, 2018 1:48 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible and Irreversible
Replies: 4
Views: 267
### Re: Reversible and Irreversible
For irreversible reactions, w=-(Pext)(deltaV). For reversible reactions, w=-nRTln(v2/v1).
Sun Jan 21, 2018 1:42 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Difference between Closed and Isolated
Replies: 10
Views: 1091
### Re: Difference between Closed and Isolated
In an isolated system, neither particles nor heat can be transferred. In a closed system, heat can be transferred but particles cannot.
Sun Jan 21, 2018 1:41 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.65
Replies: 2
Views: 122
### Re: 8.65
The solution stops at 2NO(g) + 3/2O2(g) --> N2O5(g) because you can use the enthalpy of formation of NO(g) to figure out the enthalpy of formation of N2O5(g). For 2NO(g) + 3/2O2(g) --> N2O5(g), deltaH is -169.2 kJ/mol. Thus, 1(deltaHfN2O5) - 2(deltaHfNO) = -169.2 kJ/mol. Using the appendix, 1(deltaH...
Sun Jan 21, 2018 1:30 am
Forum: Calculating Work of Expansion
Topic: Reversible vs Isothermal
Replies: 3
Views: 248
### Re: Reversible vs Isothermal
A reversible isothermal reaction is one in which the volume changes slowly at a constant temperature. There is no heat transfer, so q=0, so deltaU=w.
Sat Jan 20, 2018 1:04 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.37
Replies: 3
Views: 187
### 8.37
For homework problem 8.37b, we are asked to calculate the enthalpy of vaporization of ethanol (given that 21.2kJ vaporized 22.45 grams). The answer key gives the answer as 43.5kJ/mol, but would 0.944kJ/g also be correct? In other words, what units are we supposed to use for enthalpy of vaporization ...
Mon Dec 04, 2017 10:42 pm
Forum: Bronsted Acids & Bases
Topic: ch 12 #33
Replies: 1
Views: 148
### Re: ch 12 #33
We are using the equation M1V1=M2V2 because the number of moles is the same between the two solutions. Thus, (0.18M)(0.5000L)=M2(0.00500L). The solution manual simply rearranges this.
Mon Dec 04, 2017 10:25 pm
Forum: Lewis Acids & Bases
Topic: 12.27
Replies: 1
Views: 171
### Re: 12.27
From the problem, we know that the concentration of HCl in the intended solution is 0.025M. Therefore, [H3O+] in the intended solution is also 0.025M. The number of moles of HCl remains the same between intended and actual solutions. From earlier in the course, we learned that M1V1=M2V2. Thus, using...
Mon Nov 27, 2017 9:14 pm
Forum: Lewis Structures
Topic: N2H6
Replies: 2
Views: 1305
### Re: N2H6
The nitrogen is already very unhappy having 9 outer shell electrons in the single bond. I imagine that it will become suicidal if you decide to give it 10 outer shell electrons with the double bond. It wasn't even supposed to have an expanded octet in the first place. Don't force the relationship or...
Mon Nov 27, 2017 9:03 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.1 Homework
Replies: 2
Views: 178
### Re: 11.1 Homework
Simply changing the concentration of the reactants or products will not change the equilibrium constant. If you add more reactant, then the reaction will shift to the right. If you add more product, then the reaction will shift to the left. In the end (after you wait a while for the reaction to reac...
Wed Nov 22, 2017 1:28 am
Forum: Hybridization
Topic: 4.95 composition of the pi bond
Replies: 2
Views: 174
### Re: 4.95 composition of the pi bond
When carbon forms single bonds, it is usually in either sp, sp2, or sp3 hybridization. The single bond is a sigma bond. If the carbon is either sp or sp2 hybridized, then it will have one (in the case of sp2) or two (in the case of sp) unhybridized p-orbitals. The extra p orbitals will form double b...
Wed Nov 22, 2017 1:19 am
Forum: Naming
Topic: Ligand IUPAC naming
Replies: 1
Views: 117
### Re: Ligand IUPAC naming
He said that there is a newer method, but we will be using the older one.
Mon Nov 13, 2017 7:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE
Replies: 3
Views: 217
### Re: AXE
The notation is AX_E_, with the _ indicating the number of terminal atoms (X) or number of lone pairs (E). If there are no lone pairs, simply omit the E (you will end up with AX_). If there is one lone pair, omit the subscript (you will end up with AX_E). If there is more than one lone pair, you wil...
Mon Nov 13, 2017 7:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: CO2 vs. H2O
Replies: 6
Views: 1396
### Re: CO2 vs. H2O
1. Draw VSEPR structures. 2. Draw dipole moments. 3. CO2 has dipole moments, but they cancel out because they are equal in magnitude and opposite in direction. Therefore, CO2 is a nonpolar molecule despite having polar bonds. H2O has dipole moments, but they do not cancel out because they are equal ...
Wed Nov 08, 2017 11:40 pm
Forum: Lewis Structures
Topic: Exceptions
Replies: 4
Views: 311
### Re: Exceptions
chromium and copper because they only need one electron to fill half or all of the d orbitals
Wed Nov 08, 2017 11:38 pm
Forum: Ionic & Covalent Bonds
Topic: Polar vs. Non-polar
Replies: 7
Views: 434
### Re: Polar vs. Non-polar
If the molecule is not symmetric, then it is (generally) polar because the dipole moments (if any) do not cancel out. If the molecule is symmetric but the outside atoms are not the same, then it is polar because the dipole moments do not cancel out. If the molecule is symmetric and the outside atoms...
Mon Oct 30, 2017 9:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2.63
Replies: 2
Views: 209
### Re: 2.63
In general, the elements to top right of the periodic table have higher ionization energies. Conversely, the elements to bottom left have lower ionization energies. The elements given in the problem all follow this trend. Just rank them by which ones are higher or righter on the periodic table.
Mon Oct 30, 2017 9:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence-shell Configuration for Transition Metals
Replies: 1
Views: 165
### Valence-shell Configuration for Transition Metals
For HW problem 2.55 c, we are asked to write the valence-shell configuration for the Group 5 transition metals. I got (n-1)d3 ns2, but the answer key says (n-1)d5 ns2. Does the question mean to ask for the fifth group of transition metals or is there some special property of Group 5 metals that make...
Mon Oct 23, 2017 10:30 pm
Forum: Quantum Numbers and The H-Atom
Topic: "No two electrons are the same..." [ENDORSED]
Replies: 5
Views: 461
### Re: "No two electrons are the same..."[ENDORSED]
No two electrons in a single atom can have the same four quantum numbers.
Mon Oct 23, 2017 10:26 pm
Forum: Quantum Numbers and The H-Atom
Topic: Abbreviating e- configurations [ENDORSED]
Replies: 7
Views: 554
### Re: Abbreviating e- configurations[ENDORSED]
It depends on what the question is asking for. I would use noble gas configuration when the question asks for it.
Fri Oct 20, 2017 3:25 am
Forum: Properties of Light
Topic: Angstrom
Replies: 3
Views: 343
### Re: Angstrom
It can refer to either. The Angstrom is a unit of length.
Fri Oct 20, 2017 3:20 am
Forum: Properties of Light
Topic: Color of visible light
Replies: 11
Views: 698
### Re: Color of visible light
No, it is not necessary.
Fri Oct 13, 2017 12:46 am
Forum: Properties of Light
Topic: Prefix Conversion
Replies: 12
Views: 661
### Re: Prefix Conversion
I will usually convert the nm into m first because most ratios use m (such as speed of light). After I finish solving the problem, I make sure that the answer is in the units that the question asks for. If the question does not satisfy, I will usually just leave it in meters.
Wed Oct 11, 2017 11:05 pm
Forum: Properties of Light
Topic: Relationship between the frequency of electromagnetic radiation and electrical field
Replies: 2
Views: 222
### Relationship between the frequency of electromagnetic radiation and electrical field
On number 1.3, the question asks for what happens when the frequency of electromagnetic radiation decreases. The solutions manual says that the correct answer is "The extent of the change in the electrical field at a given point decreases". Why is this the correct answer?
Fri Oct 06, 2017 11:34 am
Forum: Limiting Reactant Calculations
Topic: M9
Replies: 3
Views: 247
### Re: M9
For net ionic equations, the soluble compounds will dissolve in water. Then, if the separated ions are able to form insoluble compounds, we will have a precipitate. In this problem, the precipitate is Cu(OH)2. The only molecules represented in the net ionic equations are precipitates and the aqueous...
Fri Oct 06, 2017 11:22 am
Forum: SI Units, Unit Conversions
Topic: Sig Figs [ENDORSED]
Replies: 16
Views: 2101
### Re: Sig Figs[ENDORSED]
There are 3 sig figs. The 0's to the left of nonzero numbers do not count as sig figs. However, if there were 0's to the right of nonzero numbers, those 0's would be significant. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.831297755241394, "perplexity": 4533.485328900687}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655890566.2/warc/CC-MAIN-20200706222442-20200707012442-00366.warc.gz"} |
https://www.miniphysics.com/electric-current-ss.html | # Electric Current (SS)
Show/Hide Sub-topics (Current Electricity | O Level)
The electric charges in motion is called electric current and it forms the basis of current electricity. Static electricity, or electrostatics, on the other hand involves charges at rest.
Electric current (I) is the rate of flow of charges (Q).
• SI unit: Ampere (A)
• Can be measured by an ammeter (must be connected in SERIES to the circuit)
$$I = \frac{Q}{t}$$
A current of one ampere is a flow of charge at the rate of one coulomb per second.
For electric current in a metal conductor (a solid), the charge carriers are electrons. For historical reasons, the direction of the conventional current is always treated as the opposite direction in which electron effectively moves.
• Current in gases and liquid generally consists of a flow of positive ions in one direction together with a flow of negative ions in the opposite direction.
Electric current generates a magnetic field. The strength of the magnetic field depends on the magnitude of the electric current.
Current electricity consists of any movement of electric charge carriers, such as subatomic charged particles (e.g. electrons having negative charge, protons having positive charge), ions (atoms that have lost or gained one or more electrons), or holes (electron deficiencies that may be thought of as positive particles)
• If the direction of the current (charge flow) is fixed, it is known as a direct current. If the motion of the electric charges is periodically reversed; it is called an alternating current.
## Analogy to river:
In order to help you understand the concept of current better, you can think of a river. Current in an electric circuit is similar to water flowing through the river.
## Examples:
An electric current in a wire involves the movement of
1. electrons
2. atoms
3. molecules
4. protons
A. Electric current in a wire (solid conductor) involves the movement of electrons.
The lower part of a cloud has a positive charge. The cloud discharges in a flash of lightning. In which direction do electrons and conventional current flow?
As the cloud is positively charged, negative charges (electrons) flow upwards. Therefore, the conventional current flow is in the opposite direction (downwards).
A battery moves a charge of 60 C around a circuit at a constant rate in a time of 20 s. What is the current in the circuit?
Current is the rate of movement of charge.
\begin{aligned} I &= \frac{Q}{t} \\ &= \frac{60}{20} \\ &= 3.0 \, C/s \\ &= 3.0 \, A \end{aligned} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.994855523109436, "perplexity": 611.4643275604449}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296948868.90/warc/CC-MAIN-20230328170730-20230328200730-00680.warc.gz"} |
https://www.physicsforums.com/threads/planewave-cutoff-energy-convergence.549372/ | # Planewave cutoff energy convergence!
1. Nov 10, 2011
### mayerz
Hello everyone,
I have some problems with the convergence for the planewave cutoff energy, I tried to find the correct PWcE for a system with 2 atoms, I've determined the minimum k-point mesh with success, but when I compute the Total energy varying the PWcE, it seems that the convergence will be achieved till too high values of PWcE, should I change the pseudopotentials for the atoms?
I use DACAPO,
I'm Mexican by the way, so sorry if I made a mistake while I wrote this.
best,
2. Nov 11, 2011
### Useful nucleus
If the pseudopotential is hard then you may not achieve convergence until reaching to very high cutoff (~700+ eV). On the other extreme ultrasoft pseudopotentials tend to converge with much lower values. Another factor is the type of element you are studying.
Check the manual of your code and the recommended values of the pseudopotential.
3. Nov 11, 2011
### mayerz
Thanks for your response, but in fact I'm using ultrasoft pseudopotentials (Vanderbilt), It seems that the Total energy converge at 400 eV but when I compute the total Energy with higher PWcE the tot E fall again to lower values. I didnt allow the atoms to relax, so the unique converge criteria is the total Energy, should I change to a relaxation calculation?
best
4. Nov 11, 2011
### Useful nucleus
There is no need to conduct the energy convergence test in a relaxation simulation. A single point calculation is good enough to test energy convergence.
Can you tell us what the total energy difference per atom between the 400eV cutoff calculation and the more conservative one?
5. Nov 11, 2011
### mayerz
Of course! If I compute the total energy difference between the calculations done with a planewave cutoff energy of 320 and 400 eV , I get like 36 KJ/mol; something similar but in the interval of 400 - 480 eV (PWcE) I get about 4 KJ/mol; and the same with a PWcE range 480-700 eV, I get 17 KJ/mol (I've already done some calculations with higher pwce, up to 880 eV, and at this point (starting in 700) the plot seems to be almost asymptotic). But it seems to be a kind of weird to me, because I was hoping for a lower pwce value, it makes any sense?
could I take the 400 eV value as the planewave cutoff energy?
by the way I use a 6 atoms periodic model!
Last edited: Nov 11, 2011
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https://www.striveworks.com/blog/pruning-resnets-for-fun-and-profit | # Pruning ResNets for Fun and Profit
### What are Neural Networks?
Neural networks are highly parameterized functions which can be trained to fit/represent/model data.
Parameterized models are ubiquitous; even simple linear regression, fitting $$f(x) = mx+b$$ to find the best fit line is parameterized by the (learnable) slope $$m$$ and intercept $$b$$. In practice, neural networks are typically far more complex than simple linear regression. Typical neural network models are a composition of several to many simpler parameterized functions often referred to as layers. We tend to think of data flowing through a neural network layer-by-layer; the output of one layer becomes the input the subsequent layer. These iterative transformations and the many learnable parameters in neural networks give them their expressive power–or, the ability to approximate functions and learn distributions of data.
### What is Neural Network Model Pruning
Neural network models are often over-parameterized and frequently contain millions or even billions of learned parameters. For some of the most difficult machine learning tasks, these massive models may be required to achieve state of the art accuracy (or even just acceptably good accuracy). However, in most cases, models can be greatly simplified and still maintain most of their accuracy. Neural network pruning is one method for simplifying a neural network model.
Figure 1 illustrates the pruning process. In this example, the full model’s layer has 3 inputs ($$x_1$$, $$x_2$$, and $$x_3$$), 3 outputs ($$y_1$$, $$y_2$$, and $$y_3$$), and 9 learned weights ($$w_{i,j}$$ for $$i, j\in {1, 2, 3}$$). The output $$y_1$$ is a weighted sum of the inputs:
$y_1 = w_{1,1}x_1 + w_{2,1}x_2 + w_{3,1}x_3.$
If it’s the case that $$|w_{1,1}| + |w_{2,1}| + |w_{3,1}|$$ is very close to zero, then $$y_1$$ will be very close to zero for most inputs (assuming none of the $$x_i$$’s are very large).
### Figure 1:
A simple example of pruning. Removing one output feature reduces the number of learned weights (edges) and the amount of computation required to compute all the layer outputs.
If this is the case, then $$y_1$$ varies very little with the network’s input and thus has little impact on the network’s predictions. Pruning exploits this insensitivity by simply removing the output $$y_1$$ and the weights used to compute it ($$w_{1,1}$$, $$w_{2,1}$$, and $$w_{3,1}$$); note this is equivalent to removing the weights or simply setting $$y_1$$ to be a constant value of 0.
Technical Note: If we remove the weights $$w_{1,1}$$, $$w_{2,1}$$, and $$w_{3,1}$$ thereby removing the output $$y_1$$, then we also need to adjust the layer immediately following the one pictured. This is because the subsequent layer originally expected three inputs ($$y_1$$, $$y_2$$, and $$y_3$$) but is now only receiving two inputs. The result will be that a few weights, which were applied solely to $$y_1$$, are no longer needed and can (must) also be removed.
### Figure 2:
A high-level view of ResNet18 which comprises 8 residual blocks.
ResNet models are deep neural networks that are composed of a sequence of residual blocks. Figure 2 shows a high level view of ResNet18 which is composed of 8 residual blocks. In a traditional convolutional neural network, the data flows along a single path forward, from one layer to the next. The residual blocks, which form the basis of ResNets, create skip connections allowing input data to bypass (or skip) some of the computation that would otherwise be done in the block–effectively creating two forward paths along which the data flows. One purpose of these skip connections is to shorten the path from input to output (or, more specifically, from output to input during a backwards pass) in an attempt to mitigate the vanishing gradient problem (see technical note for all the gory details). As a result, ResNets maintain the expressive power of deep neural networks without suffering (as badly as other deep networks) from vanishing gradients.
### Figure 3:
The computational path through this residual block preserves the size and shape of the input tensor allowing for the final point-wise addition of the block’s input tensor with the block’s output tensor.
Technical Note (vanishing gradient): The vanishing gradient problem refers to a phenomena where updates to weights (especially in early layers of a very deep network) become infinitesimally small preventing them from learning meaningful features. To illustrate the cause of the vanishing gradient and illustrate how skip connections lessen the risk of it occurring, consider a traditional neural network with 5 layers: $$f_1, f_2, f_3, f_4,$$ and $$f_5$$ where for any input $$x_0$$ the output is: $y=f_5(f_4(f_3(f_2(f_1(x_0))))).$ For notational simplicity, let’s denote $$y_i=f_i(f_{i-1}(…f_1(x_0)))$$ so that $$y=y_5=f_5(y_4),$$ etc. And, to abuse notation slightly we’ll simultaneously use $$f_i$$ to be the function which represents the $$i^{\text{th}}$$ layer and the learned weights (or parameters) contained in that layer. Weight updates at each layer will have the form: $f_i\leftarrow f_i - \lambda \frac{\partial L}{\partial f_i}$ where the partial derivative (gradient) is evaluated at that layer’s input, $$y_{i-1}$$ and $$L$$ represents whatever loss function is being optimized. As we update the weights in every layer, we compute the gradient for each layer (recycling any computation we can to avoid doing it twice). $\frac{\partial L}{\partial f_5} \rightarrow \text{directly computed}$ $\frac{\partial L}{\partial f_4} = \frac{\partial L}{\partial f_5}\cdot \frac{\partial f_5}{\partial f_4} \rightarrow \text{(recycled) (computed)}$ $\frac{\partial L}{\partial f_3} = \frac{\partial L}{\partial f_5}\cdot\frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}$ $\frac{\partial L}{\partial f_2} = \frac{\partial L}{\partial f_5}\cdot\frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}\cdot\frac{\partial f_3}{\partial f_2}$ $\frac{\partial L}{\partial f_1} = \frac{\partial L}{\partial f_5}\cdot\frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}\cdot\frac{\partial f_3}{\partial f_2}\cdot\frac{\partial f_2}{\partial f_1}$ If each of the terms $$\frac{\partial f_i}{\partial f_{i-1}}$$ are small (e.g. smaller in absolute value than 1) then the product of many such terms quickly becomes vanishingly small and, as a result, the weights of the first layer(s) are essentially static. If we insert a skip connection between layers 1 and 5 (so that the input to layer 5 consists of the output of layer 4 added to the output of layer 1) then our network description is altered slightly (and so are the derivatives). The network becomes: $y=f_5(f_1(x_0) + f_4(f_3(f_2(f_1(x_0))))).$ And the gradients (partial derivatives) become: $\frac{\partial L}{\partial f_5} \rightarrow \text{ (unchanged)}$ $\frac{\partial L}{\partial f_4} = \frac{\partial L}{\partial f_5}\cdot \frac{\partial f_5}{\partial f_4}\rightarrow \text{ (unchanged)}$ $\frac{\partial L}{\partial f_3} = \frac{\partial L}{\partial f_5}\cdot\frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}\rightarrow \text{ (unchanged)}$ $\frac{\partial L}{\partial f_2} = \frac{\partial L}{\partial f_5}\cdot\frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}\cdot\frac{\partial f_3}{\partial f_2}\rightarrow \text{ (unchanged)}$ $\frac{\partial L}{\partial f_1} = \frac{\partial L}{\partial f_5}\left(\frac{\partial f_5}{\partial f_1} + \frac{\partial f_5}{\partial f_4}\cdot\frac{\partial f_4}{\partial f_3}\cdot\frac{\partial f_3}{\partial f_2}\cdot\frac{\partial f_2}{\partial f_1}\right)$ In this case, most of the updates are the same. However, for layer 1, there is two terms (reflecting the two paths data follows to the network output). The first term has only two products (so vanishing gradient is not an issue) and the second term is the same as we previously saw (which may suffer from the vanishing gradient). The heuristic to keep in mind is that the number of steps required to get from a layer’s input to the network’s output is the number of products (of partial derivatives) that will be computed in making the weight update. If that number of steps is very high, then it is easily possible for the gradient at that layer to vanish. By inserting skip connections, one keeps the (minimal) number of steps required to get to the output relatively small.
Figure 3 shows the structure of a basic, shape-preserving residual block. In this case, the computation within the block creates an output tensor which has the same shape and size as the block’s input tensor. This allows for the coordinate-wise addition of the input tensor with the output tensor. Note that there are several types of residual blocks and the internal structure of the blocks vary somewhat; the blocks illustrated here are the simplest such blocks and are referred to as Basic Blocks. More complex blocks may contain additional Convolution-BatchNorm-ReLU groups before applying the pointwise addition. The important feature that all residual blocks share is the pointwise addition of an output tensor with the block’s input tensor.
Sometimes the computation within a residual block can alter the shape or size of the tensor moving through the block, see Figure 4. This may happen, for example, if the number of learned kernels in the final convolution layer (the number of output channels) isn’t the same as the number of input channels to the first convolution layer; in this case, the height and width of the output tensor may match the height and width of the input tensor, but the depth of the two tensors vary. Additionally, if any convolution layer within the block has a stride that is not 1, then the output tensor’s height and width will be smaller than the input tensor’s height and width. In order to make this final point-wise addition feasible, something must be done to reshape either the input tensor, the output tensor, or both.
### Figure 4:
Sometimes the computational path through a residual block alters the size and shape of data passing through the block. In these cases, without modification, the block’s input tensor cannot be added point-wise to the output tensor.
The solution which is typically employed by ResNet architectures is to insert, wherever necessary, a lightweight convolution layer (1x1 convolution) with a BatchNorm chaser (see Figure 5). Doing this allows for the needed flexibility to reshape the input and maintain the feasibility of the final pointwise addition.
### Figure 5:
By inserting a relatively lightweight resampling function (convolution) the network can reshape the input tensor to match the output tensor’s shape making the point-wise addition possible.
### Preparing to Train and Prune ResNets
To prune a convolutional neural network one selects (via any number of criteria) convolutional filters/kernels to remove. Since each convolutional filter/kernel produces a channel (or slice) of the layer’s output tensor, removing a kernel has the immediate impact of reducing the number of channels in the output tensor. Thus, if we were to remove a kernel from the second convolutional layer in a residual block that originally preserved shapes (e.g. as in Figure 3) we suddenly find ourselves in a position where shapes have been altered (e.g. as in Figure 4). To prepare for inevitably changing shapes, we ensure that every residual block contains a 1x1 convolution layer (as shown in Figure 5) and optionally also includes the batch norm layer depicted there. We use that convolutional “through” layer to resize the block’s input to match the shape of the block’s output; as we prune the block’s internal layers, we adapt the through layer so that output shapes always match. Pruning the first convolutional layer in any residual block is significantly easier. When we remove a kernel from the first convolutional layer the only other layers affected are the subsequent batch norm layer (which maintains a per-channel mean and variation) and the subsequent convolution layer (whose kernels expect a certain number of input channels).
Ideally, when pruning a neural network, the kernels selected for removal are those which are not impacting the model’s ability to make predictions. However, in practice, rather than no impact those kernels have a small impact on model performance and pruning many kernels simultaneously can have a larger impact on performance. As a result, after pruning a model, it is important to allow for a modest amount of additional training–often called fine-tuning. Compared to the cost of training a full model to convergence, the cost of fine-tuning a pruned model is very small. When viewed as a whole, the training and pruning process follows this pattern:
1. Train the full model (as usual, typically long).
2. Prune a modest amount of the model.
3. Resume training (pruned model, typically short).
4. If pruned model recovers sufficient accuracy, repeat from step 2.
### Why not just train a pre-pruned network?
At first glance it may seem like this process: train a full model, prune, fine-tune, repeat, is unnecessarily complicated. Why don’t we just start with the smaller model training it from scratch?
The first challenge one encounters is simple: how do you know the right starting size of the model should you use? If one initially chooses a model which is too small, the accuracy may simply never be good enough and one would have to retrain with a larger network (again becoming an iterative process which doesn’t simplify the original one). If the initial model is still too large, one could again prune (again becoming iterative). In practice, and for reasons which are not fully understood, training a smaller model from scratch tends to produce worse models than training a very large model and subsequently pruning. In other words, if we applied the above pruning process to find the right starting size, then randomly initialize the small model and train it would be very unlikely that we would achieve comparable accuracy. One conjecture as to the source of this problem is the challenge of getting good weight initializations.
In [3] the authors refer to this as the lottery ticket hypothesis. Roughly, the idea is that by starting with a large (fat) model, i.e. one with many kernels in each layer, one effectively buys many lottery tickets (each kernel being a lottery ticket). Before training starts, it is impossible to know which will be the winners, but once the winners have been determined, the rest are no longer needed and can be discarded. Then, trying to train from a small model is akin to trying to win the lottery by only purchasing a minimal number of tickets. The authors showed that if they stored the original weights, trained a model to convergence, determined which kernels were winners, then pruned the model (to only include the winners), reset the winners to their original weights, and re-train they could recover the highly accurate model. However, their result is still not conclusive as it was later shown to not always be effective, and in practical terms it wasn’t very useful (because learning which tickets were winners required training the full model). So, the short answer as to why we follow this iterative approach is simple: in practice, not only does it work, but it works better than any other strategy currently known.
### How to Select Kernels to Prune
There is a wide body of research around how to select which kernels to prune from any given neural network model; in this section we describe very briefly some of that research. Pruning strategies roughly fall into two categories: data-agnostic pruning and data-aware pruning.
One of the earliest proposed pruning strategies [5] involved locally approximating a loss function and estimating the impact on the loss function if any particular neuron were to be pruned–pruning the neurons with the least negative impact. A recent data-aware approach was proposed initially as a means to attempt to explain neural network predictions. This approach [2] was to remove convolutional kernels one-by-one and measure the impact on the predictive ability for each class. The goal was that by identifying a small number of kernels essential to accurate predict a class one could explain what it was about those kernels which made that prediction possible. While the method turned out to not lead to easy explanations a novel side-effect was that pruning could be done aggressively and in a single shot if one only kept a few kernels that were the most important for each class, e.g. at each layer one might keep the three most important (critical) kernels for each class–this frequently included a lot of overlap as kernels were often critical for more than one class. With a small amount of fine-tuning the models were shown to recover most of their accuracy. The real limitation with this approach however was the computational expense to determine which filters were critical. The model would have to be re-validated once for each kernel in the network (removing them one at a time and validating); for deep models with many, many kernels (and for large datasets) this computation may be prohibitively expensive.
Data agnostic pruning strategies are very popular because they tend to be sufficiently effective and relatively inexpensive. We previously hinted that if the sum of the absolute values of a kernel’s weights was small then that kernel would produce an output that was almost always close to 0–and is therefore not needed. This is indeed a common pruning strategy and there are (at least) two ways to look at “how small” a kernel’s weights are; pruning is accomplished either by removing all the kernels that are smaller than a threshold, or by removing the smallest kernels regardless of their nominal size. The first way to “size” a kernel is to compute the max norm of that kernel, also called the $$\ell_\infty$$ norm, or simply, the largest absolute value of any weight in the kernel. This strategy appears in several papers including [6], it is easy to implement and typically quite effective. A second method for measuring the size of a kernel is to instead compute the kernel’s $$\ell_1$$ norm, or the sum of the absolute values of the weights. Again, after computing the sizes of the kernels one either prunes kernels whose size falls below a threshold or just the smallest few kernels in the network. This strategy is (obviously) very similar to the first but is also frequently used including [4]. Less common are data-agnostic strategies which do not rely on kernel size. One such strategy [1] revolves around identifying redundant kernels and removing redundancy. They identify redundant kernels by computing the cosine similarity of the outputs of kernels given random inputs. If the cosine similarity is high, than for many inputs the output of the two kernels are nearly identical and therefore both kernels are not needed. Surprisingly, or maybe not, the work of [7] demonstrated that simply randomly pruning kernels is comparably effective to any of these data-agnostic strategies–a testament to how plastic (adaptable) these neural network models are.
So, how should you choose which kernels to prune? In light of [7] one might be tempted to think that they should simply randomly prune; however, the real take-away is that all of these strategies–at least on standard, benchmark datasets–perform their desired function. In all these cases, model sizes were dramatically shrunk with minimal loss in accuracy. So, in reality, the answer is: you should choose which ever method works for your data and your model keeping in mind that it is a good idea to be flexible.
## Real Impact of Pruning
Neural network pruning has (at least) two impacts.
First, a pruned model is necessarily a subset of its un-pruned parent. This means that the pruned model has a strict subset of the weights of its parent and therefore less expressive capacity. As an analogy, recall the function $$f(x)=mx+b$$ for simple linear regression. If we prune one of the parameters, for example the intercept, we are left with $$g(x)= mx$$. Anything expressible by $$g(x)$$ is equally expressible by $$f(x)$$ (setting $$b=0$$). But, there are some things which can be expressed by ((f(x))) that cannot be expressed by $$g(x)$$. While a pruned model must be less expressive than its parent, it is not necessarily the case that a pruned model must be less accurate than its parent. In our analogy, for example, if the data we were representing naturally had an intercept of 0, then both models would be equally accurate. In practice it is hard (maybe impossible) to know how accurate a pruned model can (or will) be until it is pruned and tested.
Second, since a pruned model contains a strict subset of the weights of its un-pruned parent, it is necessarily the case that less computation must be done to compute the pruned network’s output than its parent. As a result of requiring less computation, the inference speed of a pruned model is at least as fast (usually faster) than its parent. There are many subtle factors which impact how much (if any) speed-up will be seen including: how much of the network was pruned (the more that is pruned the more likely it is to see a larger speed-up), how well the network’s computation is parallelized (pruning can impact positively or negatively the parallelization efficiency), I/O speeds (if it takes longer to load data than to do the computation then doing less computation will not produce a speed-up because it doesn’t affect the I/O speed), etc.
In the following sections, we demonstrate the real affects of training and iteratively pruning a ResNet18 model on a dataset containing images of vehicles–the task being to identify the predominant color of the vehicle.
### Minimal Loss of Model Accuracy
First we examine the impacts on the accuracy of our model as we train and iteratively prune.
Figure 6 shows the validation accuracy over time as we perform this iterative procedure. The full model is updated through 40,000 iterations (batches of data) achieving an accuracy of just over 95% on the validation dataset. We then prune approximately 5% of all the convolutional kernels in the model and continue training. After the initial pruning little or no accuracy is lost and the model continues to learn. We continue to prune approximately 5% of the model (removing approximately 5% of the convolutional kernels) and immediately fine-tune the model for 8000 batches. Note that, after the initial pruning operations, the accuracy (if lost at all) is recovered significantly quicker than after 8000 iterations–indicating that would could have achieved similar results with less fine tuning. By the final few pruning iterations we performed, the initial drop is accuracy becomes more pronounced, although in every case the model is able to recover to at least 95% accuracy.
### Figure 6:
The validation accuracy of a ResNet18 model as it is trained. The first 40,000 batches are training a full model. Then, pruning iterations begin. Each pruning iteration consists of removing approximately 5% of the convolutional kernels from the existing ResNet18 model and then fine-tuning (re-training) for 8000 additional batches.
### Reduction in Model Size
In Figure 6 we estimated the percentage of convolutional kernels removed from the model. Note, this estimate is rough for two reasons: first, we can only remove an integer number of kernels (so we almost never remove precisely 5% of the model), and second, we are actually attempting to remove 5% of the current model at each step, so as the model shrinks, 5% of the current model is a decreasing fraction of the original model. But, removing entire kernels is not the only impact on the model. As previously discussed, when we remove some kernels, the remaining kernels in subsequent layers shrink (to accept inputs with fewer channels). In Figure 7 we illustrate the relative impact on model size as the pruning occurs. This model size is measured by examining the memory (disk space) required to store the model (its learned parameters). Since the exact model size is less important, we show here the size of pruned models relative to the full model (a ratio of pruned model to full model). This demonstrates that we can remove almost 80% (79.1%) of the models learned parameters without negatively impacting the predictive performance.
### Figure 7:
The relative model size as the model is initially trained (full model) then iteratively pruned. Note, the size referred to here is the relative size of the learned weights and is directly proportional to the number of learned weights in the pruned model. Specifically, the final model has 20.9% the number of learned parameters as the full model, or, in other words, almost 80% of the learned weights were removed (pruned) from the full model.
### Improvement in Inference Time
While the direct impacts of a smaller model size may not be obvious (e.g. smaller memory footprint requiring less power), pruning a model also has a positive effect on the speed at which the model can make predictions. Figure 8 illustrates how much additional throughput the model can produce, specifically, our model which has been pruned by almost 80%–with no loss in accuracy–can make almost 65% more predictions per second than the full model.
### Figure 8:
As the model shrinks, inference time improves and more images can be processed in a fixed amount of time. With nearly 80% of the model pruned (and no noticeable loss in validation accuracy) we observe almost a 65% increase in the number of images that can be processed per second.
## Conclusion
Pruned models are (almost always) better–in about every way that actually matters–than their full, over-parameterized counterparts. Pruned models are less likely to overfit data; pruned models (may) maintain all or most of the accuracy of the full model; and, pruned models require less memory, less energy, and inference faster.
## References
1. Babajide O Ayinde and Jacek M Zurada. 2018. Building efficient convnets usingredundant feature pruning.arXiv preprint arXiv:1802.07653(2018).
2. Mihaela Dimovska and Travis Johnston. 2019. A Novel Pruning Method for Convolutional Neural Networks Based off Identifying Critical Filters. In Proceedings of the Practice and Experience in Advanced Research Computing on Rise of the Machines (PEARC19). Association for Computing Machinery, New York, NY, USA, Article 63, 1–7.
3. Jonathan Frankle and Michael Carbin. 2019. The Lottery Ticket Hypothesis: Finding Sparse, Trainable Neural Networks. International Conference on Learning Representations (ICLR), Available: https://arxiv.org/abs/1803.03635.
4. Hengyuan Hu, Rui Peng, Yu-Wing Tai, and Chi-Keung Tang. 2016. Network trimming: A data-driven neuron pruning approach towards efficient deep architectures. arXiv preprint arXiv:1607.03250 (2016).
5. Yann Le Cun, John S. Denker, and Sara A. Solla. 1990. Optimal brain damage. Advances in neural information processing systems. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 598–605.
6. Hao Li, Asim Kadav, Igor Durdanovic, Hanan Samet, and Hans Peter Graf. 2016. Pruning filters for efficient convnets. arXiv preprint arXiv:1608.08710 (2016).
7. Deepak Mittal, Shweta Bhardwaj, Mitesh M Khapra, and Balaraman Ravindran. 2018. Recovering from Random Pruning: On the Plasticity of Deep ConvolutionalNeural Networks. In 2018 IEEE Winter Conference on Applications of ComputerVision (WACV). IEEE, 848–857.
Travis Johnston Travis Johnston is a Senior Data Scientist at Striveworks. He holds a PhD in Mathematics from the University of South Carolina. Before joining Striveworks in the beginning of 2021, he was a Postdoctoral Researcher at the University of Delaware, and a Staff Research Scientist at Oak Ridge National Lab. He is the author/co-author of many scientific publications in mathematics, machine learning, and high performance computing and has mentored many undergraduate and graduate students as well as several postdocs. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 1, "x-ck12": 0, "texerror": 0, "math_score": 0.8199832439422607, "perplexity": 754.050097760256}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711108.34/warc/CC-MAIN-20221206124909-20221206154909-00094.warc.gz"} |
https://www.physicsforums.com/threads/low-pass-filter-uniform-gauss-distribution.871002/ | # Low pass filter (uniform/gauss distribution)
• Start date
• #1
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0
## Homework Statement
[/B]
I have got data x, which is formed like uniform distribution.
After using discrete low pass filter I got output data u, which is Gauss distribution.
What is explanation, why using that filter, we from uniform distribution can get Gauss distribution?
## Homework Equations
Low pass filter formula:
## The Attempt at a Solution
[/B]
Filtred data starts to reach mean value of input data.
Related Engineering and Comp Sci Homework Help News on Phys.org
• #2
collinsmark
Homework Helper
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Discrete time filtering of noisy signals essentially involves the addition of scaled, random numbers. Each input sample can be thought of being associated with a random number (conforming to a random variable with some known distribution, such as uniform distribution, for example).
Each output sample involves scaling these random numbers by some amount and adding them together. In an IIR filter (like this one), this also involves summing new, scaled inputs (new random numbers) together with scaled, previous outputs (old random numbers). The point of what I'm trying to say here is it involves the summing of random numbers.
-----
Let's take a step back a little and talk about the summing of random variables.
Flip a fair coin. It's either heads or tails. Let's assign 0 to tails and 1 to heads. It's uniformly distributed between 0 and 1.
0 [p = 1/2] tails
Now flip two coins (or the same coin twice) and add the results together. The distribution isn't uniform any more. The possible outcomes are:
0 [p = 1/4] (both tails)
2 [p = 1/4] (both heads)
Now flip the coin three times. Possible outcomes:
0 [p = 1/8] (all tails)
3 [p = 1/8] (all heads)
Four flips:
0 [p = 1/16] (TTTT)
1 [p = 4/16] (HTTT --or-- THTT --or-- TTHT --or-- TTTH)
2 [p = 6/16] (HHTT --or-- HTHT --or-- HTTH --or-- THHT --or-- THTH --or-- TTHH)
3 [p = 4/16] (HHHT --or-- HHTH --or-- HTHH --or-- THHH)
4 [p = 1/16] (HHHH)
Notice that as we sum together more random flips that the distribution function gets smoother and closer to a bell shape.
What would happen if we increased the number of flips to a very large number?
---
Now back to the discrete filter. Things might be a little more complicated here because the some of the random variables are scaled before they are added.
What does the Central Limit Theorem, or something very much like it, tailored to this situation, have to say about this?
• #3
collinsmark
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I don't want you to get bogged down with the Central Limit Theorem. It does apply in the case of adding up all the coin flips. But I only mentioned it in my above post as a point of reference (and the fact that the Central Limit Theorem involves the Gaussian distribution function).
But it doesn't really apply directly in the case of the discrete filter because there is weighting and scaling going on. The distribution of the output of your discrete filter is not truly Guassian, even if it is pretty close.
If you wish to find the true, mathematically accurate probability distribution of the filter's output, it may help to study what happens when you add two random variables together, each with a different probability distribution, and calculate the distribution of the sum. (Hint: Discrete convolution is involved in the distribution function of the sum). [Edit: Actually that's continuous (not discrete) convolvution that is involved in the probability density function of the sum. The filter performs discrete convolution when its doing its filtering thing, but if we want to find solve for the probability density functions, continuous convolution is involved.]
Take that a step further and iteratively ["recursively" might be the better word] convolve the weighted, previous distribution function of the output with the weighted, distribution function of the input. The mathematics can get scary, but if you can do it, you'll have your precise answer.
I'm not sure if this is what you are looking for, or if you are trying to find a more subjective (less precise) answer.
[Edited for clarification.]
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• #4
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I like your approach to this question. I hadn't thought, that output is sum of two different distributions. Actually output isn't Gaussian distribution, but it just looks like that?
Filter output can be calculated recursively using difference equation:
$$y(n) = \sum_{k=0}^M b_nx(n-k)+\sum_{k=1}^N a_ky(n-k)$$
Or using convolution operation:
$$y(n) =h(n) * x(n),$$
where $h(n)$ is impulse response.
In my case transfer function of a IIR discrete time filter:
$$H(z) =\frac {0.111} {1-0.889z^{-1}}$$
So then I tested few things in Matlab:
Code:
clear all, clc
n=1000;
x = -0.3 + (0.9-(-0.3)).*rand(n,1);
y = filter(0.111,[1 -0.889],x);
figure(1)
subplot(211)
plot(x)
title('Input data')
ylabel('x(n)')
subplot(212)
plot(y)
title('Output data')
ylabel('y(n)')
figure(2)
subplot(211)
hist(x,24)
title('Input data histogram')
subplot(212)
hist(y,24)
title('Output data histogram')
figure(3)
a=[1, -0.889];
b=[0.111];
[h,t]=impz(b,a,1000);
subplot(211)
stem(t,h);
title('Impulse response h(n)')
subplot(212)
y1=conv(h,x)
plot(y,'-r')
ylabel('y(n)')
And this is result with convolution formula:
There I tested that I can get same results with convolution formula and orginal filter formula. Is there all OK?
But I guess that is not what I exactly need to explain output distribution. As I understand your hints, I need to do convolution operation with two different distribution functions.
I know probability density function for uniform distribution (input data):
$$F(x) =\frac {x-a+1} {b-a+1}, x\in [a, b]$$
But it's not clear with "weighted, previous distribution function of the output". How can I describe it with probability density function?
• #5
collinsmark
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I like your approach to this question. I hadn't thought, that output is sum of two different distributions. Actually output isn't Gaussian distribution, but it just looks like that?
Right. If my intuition and memory serves me, the probability density function of the filter's output will not be Gaussian unless $T$ approaches infinity. (Don't ask me to prove that though. )
In this exercise, $T$ is 9. The number 9 is pretty close to infinity, which is why the output looks sort of Gaussian, but it's not quite there, so the distribution function is not truly Gaussian.
By the way, if the probability density function of the input was Gaussian, then the filter's output would be Gaussian regardless of what $T$ is. But that's a special case that does not apply to this exercise.
Filter output can be calculated recursively using difference equation:
$$y(n) = \sum_{k=0}^M b_nx(n-k)+\sum_{k=1}^N a_ky(n-k)$$
Or using convolution operation:
$$y(n) =h(n) * x(n),$$
where $h(n)$ is impulse response.
In my case transfer function of a IIR discrete time filter:
$$H(z) =\frac {0.111} {1-0.889z^{-1}}$$
So then I tested few things in Matlab:
Code:
clear all, clc
n=1000;
x = -0.3 + (0.9-(-0.3)).*rand(n,1);
y = filter(0.111,[1 -0.889],x);
figure(1)
subplot(211)
plot(x)
title('Input data')
ylabel('x(n)')
subplot(212)
plot(y)
title('Output data')
ylabel('y(n)')
figure(2)
subplot(211)
hist(x,24)
title('Input data histogram')
subplot(212)
hist(y,24)
title('Output data histogram')
figure(3)
a=[1, -0.889];
b=[0.111];
[h,t]=impz(b,a,1000);
subplot(211)
stem(t,h);
title('Impulse response h(n)')
subplot(212)
y1=conv(h,x)
plot(y,'-r')
ylabel('y(n)')
And this is result with convolution formula:
There I tested that I can get same results with convolution formula and orginal filter formula. Is there all OK?
Yes, I think that looks right to me. Except if I were you I would change your 0.111 and 0.889 numbers to 1/9 and 8/9 (or at least drag out the precision a little longer). Filters, whether they be analog or digital (including discrete time filters), can in some cases be pretty sensitive to precision and rounding errors.
Of course, filters involve convolution as part of their very operation.
But the process for finding the mathematically precise probability density function (pdf) of a filter uses a different process than what the filter uses directly, even though they both involve convolution.
Both processes use convolution. But they use it in different ways. More on this below.
But I guess that is not what I exactly need to explain output distribution. As I understand your hints, I need to do convolution operation with two different distribution functions.
Yes, the process involves convolving two different probability density functions. And more so, it involves repeating this process a large (perhaps approaching infinity) number of times.
I know probability density function for uniform distribution (input data):
$$F(x) =\frac {x-a+1} {b-a+1}, x\in [a, b]$$
Firstly, that's closer to the Cumulative Probability Function, not the Probability Density function.
Secondly, you don't need the '1's. I suggest getting rid of those.
I would say the cumulative probability function $F_x (x)$, for a uniform random variable is
$$F(x) = \begin{cases} 0 & x < a \\ \frac{x - a}{b - a} & a \leq x \leq b \\ 1 & x > b \end{cases}$$
To find the Probability Density Function (PDF), just take the derivative of that. It should give you as constant, non-zero value between $a$ and $b$ and 0 elsewhere.
So the probability density function $f_x$ is
$$f_x = \begin{cases} 0 & x < a \\ \frac{1}{b - a} & a \leq x \leq b \\ 0 & x > b \end{cases}$$
But it's not clear with "weighted, previous distribution function of the output". How can I describe it with probability density function?
I'll try to get you started.
Suppose we had a random variable what was uniformly random between 0 and 1. Let's call that variable $x$. Let's call its PDF $f_x$.
Since the function $f_x$ is a probability density function, the area under the curve must be 1. So in this case, the amplitude of $f_x$ is 1 between $0 \leq x \leq 1$ and zero everywhere else.
Probability density function for our example $f_x$:
$$f_x = \begin{cases} 0 & x < 0 \\ 1 & 0 \leq x \leq 1 \\ 0 & x > 1 \end{cases}$$
So what if we were to multiply $x$ by $\frac{1}{10}$. What is the probability density function, $f_{x/10}$, of that?
If you were to guess that it would be $\frac{1}{10} f_x$ that would seem deceptively simple. And it would also be wrong. The maximum possible value for $x$ is 1. So the maximum possible value for $\frac{1}{10}x$ is $\frac{1}{10}$. And we also need to scale the amplitude by the inverse of our constant so that the area under the curve remains 1.
Probability density function for our example $f_{x/10}$:
$$f_{x/10} = \begin{cases} 0 & x < 0 \\ 10 & 0 \leq x \leq 0.1 \\ 0 & x > 0.1 \end{cases}$$
So when we multiply our random variable by a small fraction, the resulting probability density function gets squished up; it gets narrower. But the height of the function grows taller (keeping the area under the curve a constant 1).
---
This is the sort of thing you will have to do in your problem. The input signal gets multiplied by $1/9$. So you'll have to find a new probability density function of the input $x$ that has a PDF that is squished to 1/9th and 9 times taller.
You'll then convolve that result with the PDF of the filter's previous output, scaled by $8/9$
----
It might help to start from the beginning. $u_o = x_0$, so the PDF of $u_0$ has the same PDF as the input.
To find the PDF of $u_1$ you'll need to convolve $f_{x/9}$ with $f_{8 u_0/9}$
Note that the PDF of $u_1$ is not uniform. It is certainly not Gaussian either. From here on out, you'll need to treat the PDFs of the outputs as having arbitrary shapes since they're neither Gaussian nor uniform, but somethings sort of in between (sort of).
Keep on going indefinitely with the pattern. And good luck!
Last edited:
• #6
collinsmark
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Oh, and by the way, even though you are working with a discrete time filter, the PDFs involved are continuous functions (unless you are artificially imposing digital constrains such as those associated with a 32-bit floating point value or some such. But I don't think that is what you are interested in). The convolutions that I was talking about in my last post were continuous convolutions, not discrete.
So when you calculate the output stream by convolving the input stream with $h[n]$, then that is discrete convolution. That's fine. That's what discrete time filters do. But that doesn't tell you anything about the probability distribution of the output.
When you are finding the resulting PDFs, calculating $f_{u[n]} = f_{8 u[n-1]/9} \ast f_{x/9}$, that is continuous convolution to be done with integration.
Last edited:
• #7
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Input distribution:
$$f_x = \begin{cases} 0, & x \lt -0.3 \\ \frac {1} {1.2}, & -0.3 \leq x \leq 0.9 \\ 0, & x \gt 0.9 \end{cases}$$
Input distribution scaled by $1/9$::
$$f_{x/9} = \begin{cases} 0, & x \lt -\frac {1} {30} \\ 7.5, & -\frac {1} {30} \leq x \leq 0.1 \\ 0, & x \gt 0.1 \end{cases}$$
Filter's previous output scaled by $8/9$:
$$f_{8u_{0}/9} = \begin{cases} 0, & x \lt -\frac {4} {135} \\ 8\frac {7} {16}, & -\frac {4} {135} \leq x \leq \frac {4} {45} \\ 0, & x \gt \frac {4} {45} \end{cases}$$
Then I need to calculate:
$$f_{u_{n}}(z) = \int_{\infty}^{-\infty} f_{8u_{n-1}/9}(x) f_{x/9}(z-x) \, dx$$
First iteration n=1:
$$f_{u_{1}}(z) = \int_{\infty}^{-\infty} f_{8u_{0}/9}(x) f_{x/9}(z-x) \, dx$$
But I have got 1000 random numbers (input), is it mean that to calculate resulting PDF I need to do n=1000 iterations?
• #8
collinsmark
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Input distribution:
$$f_x = \begin{cases} 0, & x \lt -0.3 \\ \frac {1} {1.2}, & -0.3 \leq x \leq 0.9 \\ 0, & x \gt 0.9 \end{cases}$$
Input distribution scaled by $1/9$::
$$f_{x/9} = \begin{cases} 0, & x \lt -\frac {1} {30} \\ 7.5, & -\frac {1} {30} \leq x \leq 0.1 \\ 0, & x \gt 0.1 \end{cases}$$
Filter's previous output scaled by $8/9$:
$$f_{8u_{0}/9} = \begin{cases} 0, & x \lt -\frac {4} {135} \\ 8\frac {7} {16}, & -\frac {4} {135} \leq x \leq \frac {4} {45} \\ 0, & x \gt \frac {4} {45} \end{cases}$$
Then I need to calculate:
$$f_{u_{n}}(z) = \int_{\infty}^{-\infty} f_{8u_{n-1}/9}(x) f_{x/9}(z-x) \, dx$$
First iteration n=1:
$$f_{u_{1}}(z) = \int_{\infty}^{-\infty} f_{8u_{0}/9}(x) f_{x/9}(z-x) \, dx$$
But I have got 1000 random numbers (input), is it mean that to calculate resulting PDF I need to do n=1000 iterations?
Good work so far!
Before we go on though, I must ask: were you really tasked with finding the actual (mathematically exact) probability density function?
In your original post, the question was asking for a reason why the filter's output's probability density function looked Gaussian (or at least Gaussian-like) when the input's probability density function was uniform.
I ask because I think you are very close to being able to answer
1. why the filter's output's probability density function goes from being uniform to one that looks sort-of Gaussian like, and
2. why the filter's output's probability density function will never be actually Gaussian, even if it is sort of close.
On the other hand, solving for the (mathematically exact) probability density function is a lot tougher. (Heck, I'm not even sure I'm up for that challenge.)
---
You might want to try going through a few iterations to see what happens to $f_{u_n}$ at each iteration. I think that will help show 1) above, where the function starts out as uniform, then starts to look more Gaussian (sort of) with each iteration. (More on the second answer later.)
The following might help with the second answer, and if you actually did wish to solve for the actual function.
If we wanted to scale a random variable by some amount, say by $\frac{8}{9}$, and we know the original probability density function, say we call it $f_{u_n}(x)$, then the probability density function of the scaled random variable is
$$f_{8u_n/9}(x) = \frac{9}{8}f_{u_n}(9x/8)$$
Make sure that makes sense to you before we move on. (And take note for later [see below] that if the original function is Gaussian, the density function of the scaled random variable is also Gaussian, albeit with a different mean and standard deviation.)
After an infinite number of iterations (as $n \rightarrow \infty$), the probability density function is not going to change anymore. In other words, $f_{8u_n/9}(x) = f_{8u_{(n-1)}/9}(x)$.
And with that bit of insight, we can say,
$$f_{u_n}(x) = \int_{-\infty}^\infty \frac{9}{8}f_{u_n}(9z/8) f_{x/9}(x-z)dz$$
And that's the differential equation that will ultimately give you your answer. Notice that there is only one function that is unknown, and that is $f_{u_n}()$. You already know what $f_{x/9}()$ is, you've calculated that above (I did some variable substitution, btw).
What that differential equation is asking is as follows: "Suppose I had an original function and then scaled it a little bit, in a known way, to make a new function, then I convolved that with this other, known function such that the result is equal to the original function. What [original] function meets these requirements?"
I'm confident that the differential equation has a solution. But I'm not confident that I have the mathematical aptitude to solve for it. (Nor am I positive that it can be represented in closed form.) [Edit: I just came up with an idea or two on how this differential equation might be solved. But I haven't worked out the details yet.]
Even without solving for the actual function, you might be able to convince yourself why the solution is not Gaussian. Is it possible to convolve a Gaussian function with one and only one other non-Gaussian function* and produce a truly Gaussian function?
*[Edit: and not something trivial like an impulse either. I mean convolved with a uniform function, for example.]
Last edited:
• #9
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were you really tasked with finding the actual (mathematically exact) probability density function?
Actually I think that I don't need mathematically exact probability density function, that's why I didn't ask for it. Heh, we started to speak about probability density functions, then I thought that I could solve actual function. But I think I won't be able to solve that continuous convolvution integral.
So I will try to explaine the question in my homework without mathematically exact output probability density function.
By the way, I can't get it one thing:
$$f_{8u_{n}/9}(x)=\frac {9}{8}f_{u_{n}}(9x/8)$$
Why and how scale factor $8/9$ started to react like $9/8$ in the second part of equation?
When I got the answer whether my explanation is OK or not, I will inform you here.
• #10
collinsmark
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By the way, I can't get it one thing:
$$f_{8u_{n}/9}(x)=\frac {9}{8}f_{u_{n}}(9x/8)$$
Why and how scale factor $8/9$ started to react like $9/8$ in the second part of equation?
When I got the answer whether my explanation is OK or not, I will inform you here.
Multiplying the function's input by a number greater than 1 (i.e., the $\frac{9}{8}$ in $f(9 x /8)$) squishes the function along the x-axis. With this scaling factor, the output of the function when $x = \frac{8}{9}$ produces the same output as the original function when $x = 1$.
Scaling the output of the function by the same factor ensures that the area under the curve remains 1.
You have already calculated the relevant functions, $f_x(x)$, $f_{x/9}(x)$, and $f_{8x/9}(x)$ back in post #7. As a sanity check, go back and plug some numbers into them and ensure that
$$f_{x/9}(x) = 9 f_x(9x)$$
and
$$f_{8x/9}(x) = \frac{9}{8} f_x(9x/8) .$$
As an additional sanity check you should be able to confirm that the area under each curve is equal to 1.
[Edit: regarding my above notation, recall that $u_0 = x_0$, thus $f_{8u_0/9}(x) = f_{8x/9}(x)$. As far as the differential equation goes though, we don't know what $f_{u_n}(x)$ is as $n \rightarrow \infty$, yet. That is the unknown function for which the differential equation is trying to solve (and we haven't solved that yet). But we do know, whatever that function is, that $f_{8u_n/9}(x) = \frac{9}{8} f_{u_n}(9x/8)$.]
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• #11
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Now I understand that part. Thanks.
I think I calculated wrong $f_{8u_{0}/9}$ in post #7. It should be $f_{x}$ scaled by $8/9$, because $x_{1}=u_{0}$. But I did something else there.
You might want to try going through a few iterations to see what happens to $f_{u_n}$ at each iteration. I think that will help show 1) above, where the function starts out as uniform, then starts to look more Gaussian (sort of) with each iteration.
Then I tried to solve few discrete convolution iterations in Matlab. Here are results:
Something looks incorrect there.. Of course, I can see how from two uniform distributions, sum of distributions starts to look like Gaussian. But values seems incorrect.
Green line is Gaussian pdf with experimental mean and std from here (output data histogram):
I think (and actually you said it) when n goes to infinity (or even as it is in my case n = 1000), my output pdf should be simular like that Gaussian pdf, but in my case amplitude is about value 1, which is not close to Gaussian max amplitude value (4). I guess, $f_{8u_{0}/9}$ is wrong.
It's late now, I will chek it tomorrow one more time. And I think it will be OK without mathematically exact output probability density function to prove output. Graphic with iterations shows very well how convolution works and how sum of distributions starts to look like Gaussian. Just need to correct values there, I guess.
• #12
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I went through my calculations.
Input distribution:
$$f_x = \begin{cases} 0, & x \lt -0.3 \\ \frac {1} {1.2}, & -0.3 \leq x \leq 0.9 \\ 0, & x \gt 0.9 \end{cases}$$
Input distribution scaled by $1/9$::
$$f_{x/9} = \begin{cases} 0, & x \lt -\frac {1} {30} \\ 7.5, & -\frac {1} {30} \leq x \leq 0.1 \\ 0, & x \gt 0.1 \end{cases}$$
In the first iteration is filter's previous output scaled by $8/9$, which actually is $f_{x}$ scaled by $8/9$:
$$f_{8u_{0}/9} = \begin{cases} 0, & x \lt -\frac {4} {15} \\ \frac {15} {16}, & -\frac {4} {15} \leq x \leq 0.8 \\ 0, & x \gt 0.8 \end{cases}$$
Matlab code:
Code:
clear all, clc
T=0.001;
t=-0.267:T:0.801;
t2=-0.267*2:T:0.801*2
x1=7.5*(t>-1/30) - 7.5*(t>0.1);
x11=7.5*(t2>-1/30) - 7.5*(t2>0.1);
u0=0.9375*(t>-4/15) - 0.9375*(t>0.8);
u1=T*conv(u0,x1);
figure(1)
plot(t,x1,'red',t,u0,'blue')
hold on
plot((-0.267*2):T:(0.801*2),u1,'green')
grid on
xlim([-0.4 1])
legend('pdf x1','pdf u0','pdf u1=x1*u0')
u2=T*conv(u1,x11);
figure(2)
plot(t2,x11,'red',t2,u1,'blue')
hold on
plot((-0.267*2*2):T:(0.801*2*2),u2,'green')
grid on
xlim([-0.4 1])
legend('pdf x1','pdf u1','pdf u2=x1*u1')
n=1
$f_{u[1]} = f_{8 u[0]/9} \ast f_{x/9}$
n=2
$f_{u[2]} = f_{8 u[1]/9} \ast f_{x/9}$
And now, writing this post, I realized where's my mistake.. I didn't scale $f_{u[1]}$. I used $f_{u[1]}$ in n=2, but I need $f_{8 u[1]/9}$. Ehhh..
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56K | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 2, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8856070637702942, "perplexity": 680.9211086492586}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370496227.25/warc/CC-MAIN-20200329201741-20200329231741-00226.warc.gz"} |
https://cms.math.ca/10.4153/CJM-2009-038-x | location: Publications → journals → CJM
Abstract view
# Regular Homeomorphisms of Finite Order on Countable Spaces
Published:2009-06-01
Printed: Jun 2009
• Yevhen Zelenyuk
Format: HTML LaTeX MathJax PDF PostScript
## Abstract
We present a structure theorem for a broad class of homeomorphisms of finite order on countable zero dimensional spaces. As applications we show the following. \begin{compactenum}[\rm(a)] \item Every countable nondiscrete topological group not containing an open Boolean subgroup can be partitioned into infinitely many dense subsets. \item If $G$ is a countably infinite Abelian group with finitely many elements of order $2$ and $\beta G$ is the Stone--\v Cech compactification of $G$ as a discrete semigroup, then for every idempotent $p\in\beta G\setminus\{0\}$, the subset $\{p,-p\}\subset\beta G$ generates algebraically the free product of one-element semigroups $\{p\}$ and~$\{-p\}$. \end{compactenum}
Keywords: Homeomorphism, homogeneous space, topological group, resolvability, Stone-\v Cech compactification
MSC Classifications: 22A30 - Other topological algebraic systems and their representations 54H11 - Topological groups [See also 22A05] 20M15 - Mappings of semigroups 54A05 - Topological spaces and generalizations (closure spaces, etc.)
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https://math.stackexchange.com/questions/1492704/is-a-positive-series-convergent-if-the-terms-decrease | # Is a positive series convergent if the terms decrease?
Suppose positive real numbers $n_1>n_2>n_3>n_4...$ with these properties are given and you have the sum of $n_1+n_2+n_3+n_4...$ Is it possible to determine on the basis of this information whether or not the series will converge?
• No : $\sum\frac{1}{n}$ won't converge whereas $\sum\frac{1}{n^2}$ will. – Balloon Oct 22 '15 at 18:23
• If it won't converge will it then necessarily diverge to infinity? – St.Clair Bij Oct 22 '15 at 18:25
• Yes because you are adding positive terms : the case where the limit doesn't exists is excluded. – Balloon Oct 22 '15 at 18:26
• Thank you for your answers. I don't see how adding positive terms will necessarily lead to infinity: since $\sum \frac{1}{n^2}$ is also positive but does not lead to infinity. – St.Clair Bij Oct 22 '15 at 18:31
• I didn't say that ; I just said there is two possibilities, convergence to a positive term or divergence (the case $\sum(-1)^n$ where the limit doesn't exists can't be encounter if you considerate positive numbers). – Balloon Oct 22 '15 at 18:38
No, the series might converge or diverge. The two classic examples are the harmonic series, $\sum\limits_{n=0}^\infty {\frac{1}{n}}$, which diverges, and the series $\sum\limits_{n=0}^\infty {\frac{1}{n^2}}$, which converges to $\pi^2/6$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.850250780582428, "perplexity": 337.2854218372992}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038085599.55/warc/CC-MAIN-20210415125840-20210415155840-00352.warc.gz"} |
http://skybluetrades.net/blog/ | # Non-diffusive atmospheric flow #3: reanalysis data and Z500
In this article, we’re going to look at some of the details of the data that we’re going to be using in our study of non-diffusive flow in the atmosphere. This is still all background material, so there’s no Haskell code here!
# Non-diffusive atmospheric flow #2: outline & plan
As I said in the last article, the next bit of this data analysis series is going to attempt to use Haskell to reproduce the analysis in the paper: D. T. Crommelin (2004). Observed nondiffusive dynamics in large-scale atmospheric flow. J. Atmos. Sci. 61(19), 2384–2396. Before we can do this, we need to cover some background, which I’m going to do in this and the next couple of articles. There won’t be any Haskell code in any of these three articles, so I’m not tagging them as “Haskell” so that they don’t end up on Planet Haskell, annoying category theorists who have no interest in atmospheric dynamics. I’ll refer to these background articles from the later “codey” articles as needed.
I never really intended the FFT stuff to go on for as long as it did, since that sort of thing wasn’t really what I was planning as the focus for this Data Analysis in Haskell series. The FFT was intended primarily as a “warm-up” exercise. After fourteen blog articles and about 10,000 words, everyone ought to be sufficiently warmed up now…
Instead of trying to lay out any kind of fundamental principles for data analysis before we get going, I’m just going to dive into a real example. I’ll talk about generalities as we go along when we have some context in which to place them.
All of the analysis described in this next series of articles closely follows that in the paper: D. T. Crommelin (2004). Observed nondiffusive dynamics in large-scale atmospheric flow. J. Atmos. Sci. 61(19), 2384–2396. We’re going to replicate most of the data analysis and visualisation from this paper, maybe adding a few interesting extras towards the end.
It’s going to take a couple of articles to lay out some of the background to this problem, but I want to start here with something very practical and not specific to this particular problem. We’re going to look at how to gain access to meteorological and climate data stored in the NetCDF file format from Haskell. This will be useful not only for the low-frequency atmospheric variability problem we’re going to look at, but for other things in the future too.
Here’s a mixed bag of interesting links, some sciencey, some mathsy, some miscellany:
1. Network Rail Virtual Archives: OK, this might not, at first sight, sound like something interesting, but it really is. This site has original Victorian-era engineering drawings for a whole range of British railway infrastructure. Bridges, viaducts, stations, tunnels. All rendered in lovely 19th Century penmanship. The Forth Bridge is particularly nice.
2. open.NASA: A couple of years ago, NASA started a project to open-source code and data from their Earth observing and planetary missions. Open.NASA is gateway to these resources. I’ve not had a chance to look at it in huge detail yet, but there is a lot of stuff there. The list of projects on the code.NASA part looks particularly entertaining.
3. Game of Primes: Giganotosaurus is a science fiction site that publishes one (longish) short story each month. They’re often very good, and this one was particularly striking – it’s quite beautifully done, full of mystery, and feels like it could be a part of something much larger and deeper.
4. Surprising connections in mathematics: This one is a bit more technical, from the Math Overflow Q&A website. A lot of the connections people mention are very technical, but some are more accessible, for instance the link between algebra and geometry developed by Descartes and others in the 17th Century. This is something we learn about in school, and something that we don’t think about too much because it seems “obvious”. Only obvious in retrospect, of course, since it took hundreds of years for the connection to be discovered!
5. De Bruijn grids and tilings: Another technical one, but very interesting. Aperiodic tilings of the plane, like Penrose tilings, are slightly mysterious. This article gives a really clear description of one systematic method for generating such tilings. It’s a very odd and intriguing little bit of mathematics.
# Command and Control
by Eric Schlosser
My reading list recently has been chock-full of light-hearted and mood-lifting material: some Irvine Welsh novels (always guaranteed to shed a gentle light on all that’s best about the human condition), a long book about clinical depression, M. R. Carey’s interesting sort-of-zombie apocalypse/extreme mycology novel, The Girl With All The Gifts, de Becker’s The Gift Of Fear, a book all about fear and violence, and Piper Kerman’s prison memoir, Orange Is The New Black (which did spoil the mood a little having a few sparks of hope in among the gloom).
Among all this bleakness and blackness, Command and Control somehow manages to stand out as a particularly grim monument to human folly and our collective crimes against all sense and reason. It’s a book about nuclear weapons, so it never really had much chance of being too jolly, but even so, Schlosser’s decision to focus in parallel on US nuclear doctrine and nuclear weapons safety makes for some horrifying reading. It’s something of a mystery how we made it through the Cold War without either a “hot” war or at least some sort of unintended detonation of a nuclear weapon.
# Many Books & Their Reviews #2
Second round of “many books”…
# Many Books & Their Reviews #1
I’ve been doing quite a bit of reading lately, so I have 28 novels to review! All but one are from series of novels, so that’s not quite as daunting as it sounds. Still, I’ll split this into two posts to make it manageable.
# Getting From Here To There
In particular, getting from where you are now to where you want to be, in terms of your career.
As a result of an email I sent to the Haskell-Cafe mailing list a couple of weeks ago looking for someone to take over a contract I had been working on, someone contacted me asking for career advice. Clearly not someone who knew me at all, otherwise they would have known what a crazy idea that was. Anyway, this person was asking about one of the fundamental problems when you’re starting out in more or less any profession: how do you acquire the experience you need to apply for jobs that say “experience required”, which is more or less all of them?
They asked: “What is the path to getting involved in this stuff? How do I bridge the gap from just playing around with these technologies to having real world experience? It seems that most opportunities are for people with experience.” And this is exactly right. Particularly for contracting, no-one wants to hire someone they think will have to learn on the job. You need to know what you’re doing, which means getting experience somehow. And it would of course be nice to be able to eat and have a life while getting that experience.
I wrote an epic email in reply, and was told that it would have worked better as a blog post (or perhaps a short novel). So here I am, turning it into a blog post!
# Involuntary Hiatus Hiccup
It’s more than two months since I last wrote a blog article. I’ve been ridiculously busy since then and things are only just now calming down. It now looks as though I’m going to try something new, at least for three months or so, and that should provide more time for blogging. I had to drop more or less all of my personal projects for the last couple of months, which has been frustrating (no work on my data analysis book, no work on arb-fft, very little work on C2HS, a huge backlog of technical reading piling up and up and up like some Tower of Techno-Babel). Things should get back to something more like normal from now on though.
One benefit of working like a donkey for the last couple of months is that I now have a bit of money in the bank, and I’m planning to use that financial window to push some personal projects forwards. I have a few ideas, starting with “finishing” arb-fft and getting back to some work on my book. I’ll do a couple of days of paid work a week, do a bit of open-source stuff (C2HS and Hackage mostly) and work on those personal projects. And blogging. There will be blogging.
Starting tomorrow. Now though, I’m going to go outside and lie myself down in the sunshine.
# Fatherland and HHhH
by Robert Harris; Laurent Binet & Sam Taylor
These two books are tied together by the name of Reinhard Heydrich. I can’t think of a polite way of describing Heydrich. He was one of the architects of the Holocaust, a fervid Nazi, and an all-round total bastard. Hitler called him “the man with the iron heart”, which gives you some kind of idea of what kind of a git he was.
In the real world, Heydrich dies in 1942 from injuries sustained during an assassination attempt by Czech and Slovak commandos while he was “Acting Reich Protector of Bohemia and Moravia”. In the world of Fatherland, he survives, the Germans win the Second World War and Europe languishes under Nazi rule, with a sympathetic administration in the USA led by Kennedy (père rather than fils) providing no effective check on their activities. Heydrich continues in his role as second-in-command of the SS and goes on being as much as a bastard as ever.
Fatherland was published in 1992, so I’m a little late to the party (for a change). Alternative history novels set around WW2 are a popular genre, but Harris does something interesting and different. He manages to avoid any of the obvious missteps in representing a Nazified Europe by writing what starts out as a straight police procedural. The Thousand Year Reich still needs plods, apparently. Well, it’s a police state, so you do need some police. The slight twist is that the Kripo (Kriminalpolizei) was subsumed into the SS in 1939, thus becoming a sister agency to the Gestapo and so under the overall control of Himmler and his sidekick Heydrich. Our hero, Xavier March, wears the feared uniform of the SS, rationalising that he’d rather do some good wearing the uniform than no good at all.
The plot isn’t terribly unpredictable, although it’s uncovered in stages, so it’s not immediately obvious what’s going on. An upcoming summit between Hitler and Kennedy precipitates mild discomfort within the Nazi hierarchy over the Final Solution: everyone in Germany talks about the Jews “going to the East”, if they talk about the Jews at all, but that’s not quite euphemistic enough a cover-up for the kind of high-level negotiations that are coming up. Heydrich conceives a spectacularly brilliant and quintessentially Nazi solution: let’s destroy all the documents (well, that bit isn’t quite so typical Nazi, but this is a serious enough problem that we can tolerate a little disruption in the paper trail), and murder all the high-level bureaucrats involved (basically everyone who was at the Wannsee Conference, apart from Heydrich and the higher higher-ups, of course). Cue slapstick confusion between Gestapo on the one hand (killing inconvenient bureaucrats) and Kripo on the other (trying to figure out why all these fat old Nazis are getting bumped off).
As one might imagine, things don’t end so well for March. At the end of the book, after a good going-over from Heydrich and his Gestapo buddies, it looks like he won’t be drawing a whole lot of that SS pension. However, he has succeeded in getting information about the Holocaust out (not called that in Alternative Earth Germany, of course), which will soon lead to widespread condemnation of the Nazi regime, a breakdown in negotiations between the US and Germany and a new world order. You think? Well, perhaps not. If experience on Real Earth is any guide, clear and detailed documentation of atrocities usually leads to, well, not much. A stiff editorial in the Guardian. Questions in the Lords. That sort of thing. Real change, not so much.
Fortunately, of course, Heydrich didn’t survive. The evil shit died in 1942. HHhH (Himmlers Hirn heißt Heydrich) is real history, rather than alternative history, and tells the story of how that happened.
Now, a straight “history of the killing of Reinhard Heydrich” might be of interest to historians, but HHhH goes well beyond that.
Historical fiction, alternative history and “real” history have something of a funny relationship. Writing good historical fiction is exceedingly difficult. If you write a conventional novel, you get to choose the plot, the characters, the events you portray, how you render the dialogue, basically everything that goes into your book. To a great extent, you can do the same in alternative history. You choose a jumping off point where your alternative world diverges from ours and off you go. You can use historical characters without worrying too much about historical authenticity – who can say exactly how Heydrich would have responded in any given situation, if it’s a situation that never existed in the real world and thus to which there can be no witnesses? You can just make it up.
For a historical novel, you certainly don’t get to choose the plot, and you’re constrained as far as characters and events go too. You can do what C. J. Sansom does in his Matthew Shardlake novels or Patrick O’Brien in the Aubrey-Maturin novels and invent incidental characters to focus on, using the history more as a backdrop than an integral part of the novel. That gives you a great deal of freedom to write what you will while still exploiting the atmosphere and mores of the period you’re setting the novel in to add a bit of glamour. Or, you can do what Hilary Mantel did in her Wolfe Hall novels. This involves thousands of index cards recording the most trivial of recorded events in the lives of the most minor of characters of the period and an effort to weave all of those strands into a sort of “maximally historical” narrative. The fact that the Wolfe Hall novels are successful as novels within these constraints is a testament to Mantel’s genius.
And then there’s real history, where you may have to forego some of the requirements of good writing in order to present the known facts in sufficient detail to support whatever thesis you want to present. At this level, you care about details. Counting the buttons on uniforms in archive photographs may tell you which factory produced those uniforms and when, giving insight into logistics and supply. Trawling through thousands of pages of agricultural production records may help you to identify a hidden famine. Of course, you then take away the scaffolding, hiding the details. The process of tracking down all of those facts, the worries that you may have missed something, the controversies, the lacunae, the not-quite-justified leaps of logic, all of those are swept under the carpet.
HHhH doesn’t do this sweeping away. The scaffolding is there in plain sight in the form of short “writing of” chapters interspersed between the conventional narrative chapters describing the assassination attempt. It works really well, mostly because of the worried, slightly paranoid tone that Binet has. He worries about the number of buttons. He worries about what person X said to person Y on occasion Z. He doesn’t want to say that a certain German officer on the Eastern Front was driving an Opel if he doesn’t have incontrovertible evidence that said officer really was driving an Opel.
Now, handled badly, this kind of thing could descend into a sort of annoying historical pettifoggery that would serve only to distract from the real story. Here though, it’s handled well, and serves more to emphasise the malleability of history and the importance of rigour. On the face of it, whether it was an Opel or a Volkswagen doesn’t matter. But where do you stop? If you write, definitively, that it was an Opel, then some future historian researching German industrial production during WW2 may take that as evidence that Opel were producing a given vehicle at a given time from a given factory. Which may be untrue. And which may lead this hypothetical historian to draw incorrect conclusions. So that would be bad history.
What makes all this the exact opposite of annoying, indeed incredibly engaging, is that Biney truly appears to care about the people whose stories he has taken it upon himself to tell. Getting things wrong due to inattention or lack of diligence would be an insult to the people of Lidice, and to the memories of the Czech and Slovak soldiers (and many others) who gave their lives in the effort to remove Heydrich’s boot from their peoples’ shoulders.
Binet was writing HHhH around the time when Jonathan Littell was being lauded to the skies for Les Bienveillantes (in English, The Kindly Ones). Dealing as it does with the Holocaust, the war in Russia and other matters WW2-ish, this was of great interest to Binet. There are some very funny, although eventually unpublished (you can find them on the web with a little Googling) sections of HHhH where Binet frets about the likely reception of his book after the success of Littell’s book, and he has a good little bitching session about Littell’s slapdash approach to historical accurary. Slapdash in comparison to Binet, that is, so probably well within the bounds of factual accuracy any sane person would expect from a historical novel. The Opel example comes from this stuff – Littell talks about some officer’s car and Binet starts to worry that he’s missed a source that describes the car that this (real) officer was driving at the time. And if he’s missed that, what ever else might he have missed?
Now, I thought that The Kindly Ones was a brilliant novel, and the voice of the narrator was really strong and interesting (the phrase “unreliable narrator” doesn’t really do justice to secretly homosexual ex-SS officers with direct responsibility for the killing of Jews during the Holocaust living in hiding in France…), but HHhH really is something sui generis. Binet pulls off a great trick, in making us care about counting buttons (metaphorically) by tying that quest for historical fidelity to a respect for and love of the people whose stories he tells.
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https://www.physicsforums.com/threads/parallel-axis-theorem.103160/ | # Parallel Axis Theorem
1. Dec 7, 2005
### amcavoy
I know what the parallel axis theorem is, but I'm a little confused about when to use it. I recently had a problem where a hoop was rolling down an incline where I used the parallel axis theorem to find the translational acceleration and got it correct. However, I had a problem about a spool being pulled by a string (think of a yo-yo being pulled on the ground), and when I set up the equations I got the wrong answer using the P.A.T. For instance, I had:
$$F-F_{S}=ma$$
$$RF_{S}-rF=I_{CM}\alpha$$
Why isn't the ICM instead IP? I have solved the problem already and know the answer, I just can't see why the parallel axis theorem is not used. LINK: http://show.imagehosting.us/show/971155/0/nouser_971/T0_-1_971155.jpeg
2. Dec 7, 2005
### Staff: Mentor
I just depends on what you take as your axis of rotation. If you take the center of mass, then I and torques will be about that point. (And you'll have no need for the parallel axis theorem.)
But you are certainly free to use the point of contact with the floor as your instantaneous axis of rotation. But if you do, be sure to take torques about that point as well. In this case you'll need to use the parallel axis theorem to find the rotational inertia about that point.
Done correctly, you'll get the same answer either way. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8973529934883118, "perplexity": 199.47906342931117}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501170708.51/warc/CC-MAIN-20170219104610-00584-ip-10-171-10-108.ec2.internal.warc.gz"} |
http://theinfolist.com/php/SummaryGet.php?FindGo=Well-founded_set | TheInfoList
In mathematics, a binary relation ''R'' is called well-founded (or wellfounded) on a class ''X'' if every non-empty subset ''S'' ⊆ ''X'' has a minimal element with respect to ''R'', that is, an element ''m'' not related by ''sRm'' (for instance, "''s'' is not smaller than ''m''") for any ''s'' ∈ ''S''. In other words, a relation is well founded if :$\left(\forall S \subseteq X\right)\;\neq \emptyset \implies \left(\exists m \in S\right) \left(\forall s \in S\right) \lnot\left(sRm\right)$ Some authors include an extra condition that ''R'' is set-like, i.e., that the elements less than any given element form a set. Equivalently, assuming the axiom of dependent choice, a relation is well-founded if it contains no countable infinite descending chains: that is, there is no infinite sequence ''x''0, ''x''1, ''x''2, ... of elements of ''X'' such that ''x''''n''+1 ''R'' ''x''n for every natural number ''n''. In order theory, a partial order is called well-founded if the corresponding strict order is a well-founded relation. If the order is a total order then it is called a well-order. In set theory, a set ''x'' is called a well-founded set if the set membership relation is well-founded on the transitive closure of ''x''. The axiom of regularity, which is one of the axioms of Zermelo–Fraenkel set theory, asserts that all sets are well-founded. A relation ''R'' is converse well-founded, upwards well-founded or Noetherian on ''X'', if the converse relation ''R''−1 is well-founded on ''X''. In this case ''R'' is also said to satisfy the ascending chain condition. In the context of rewriting systems, a Noetherian relation is also called terminating.
Induction and recursion
An important reason that well-founded relations are interesting is because a version of transfinite induction can be used on them: if (''X'', ''R'') is a well-founded relation, ''P''(''x'') is some property of elements of ''X'', and we want to show that :''P''(''x'') holds for all elements ''x'' of ''X'', it suffices to show that: : If ''x'' is an element of ''X'' and ''P''(''y'') is true for all ''y'' such that ''y R x'', then ''P''(''x'') must also be true. That is, : Well-founded induction is sometimes called Noetherian induction,Bourbaki, N. (1972) ''Elements of mathematics. Commutative algebra'', Addison-Wesley. after [[Emmy Noether]]. On par with induction, well-founded relations also support construction of objects by [[transfinite recursion]]. Let (''X'', ''R'') be a [[binary relation#Relations over a set|set-like]] well-founded relation and ''F'' a function that assigns an object ''F''(''x'', ''g'') to each pair of an element ''x'' ∈ ''X'' and a function ''g'' on the initial segment of ''X''. Then there is a unique function ''G'' such that for every ''x'' ∈ ''X'', :$G\left(x\right) = F\left\left(x, G\vert_\right\right).$ That is, if we want to construct a function ''G'' on ''X'', we may define ''G''(''x'') using the values of ''G''(''y'') for ''y R x''. As an example, consider the well-founded relation (N, ''S''), where N is the set of all natural numbers, and ''S'' is the graph of the successor function ''x'' ↦ ''x''+1. Then induction on ''S'' is the usual mathematical induction, and recursion on ''S'' gives primitive recursion. If we consider the order relation (N, <), we obtain complete induction, and course-of-values recursion. The statement that (N, <) is well-founded is also known as the well-ordering principle. There are other interesting special cases of well-founded induction. When the well-founded relation is the usual ordering on the class of all ordinal numbers, the technique is called transfinite induction. When the well-founded set is a set of recursively-defined data structures, the technique is called structural induction. When the well-founded relation is set membership on the universal class, the technique is known as ∈-induction. See those articles for more details.
Examples
Well-founded relations which are not totally ordered include: * the positive integers , with the order defined by ''a'' < ''b'' if and only if ''a'' divides ''b'' and ''a'' ≠ ''b''. * the set of all finite strings over a fixed alphabet, with the order defined by ''s'' < ''t'' if and only if ''s'' is a proper substring of ''t''. * the set N × N of pairs of natural numbers, ordered by (''n''1, ''n''2) < (''m''1, ''m''2) if and only if ''n''1 < ''m''1 and ''n''2 < ''m''2. * the set of all regular expressions over a fixed alphabet, with the order defined by ''s'' < ''t'' if and only if ''s'' is a proper subexpression of ''t''. * any class whose elements are sets, with the relation $\in$ ("is an element of"). This is the axiom of regularity. * the nodes of any finite directed acyclic graph, with the relation ''R'' defined such that ''a R b'' if and only if there is an edge from ''a'' to ''b''. Examples of relations that are not well-founded include: * the negative integers , with the usual order, since any unbounded subset has no least element. * The set of strings over a finite alphabet with more than one element, under the usual (lexicographic) order, since the sequence "B" > "AB" > "AAB" > "AAAB" > … is an infinite descending chain. This relation fails to be well-founded even though the entire set has a minimum element, namely the empty string. * the rational numbers (or reals) under the standard ordering, since, for example, the set of positive rationals (or reals) lacks a minimum.
Other properties
If (''X'', <) is a well-founded relation and ''x'' is an element of ''X'', then the descending chains starting at ''x'' are all finite, but this does not mean that their lengths are necessarily bounded. Consider the following example: Let ''X'' be the union of the positive integers and a new element ω, which is bigger than any integer. Then ''X'' is a well-founded set, but there are descending chains starting at ω of arbitrary great (finite) length; the chain ω, ''n'' − 1, ''n'' − 2, ..., 2, 1 has length ''n'' for any ''n''. The Mostowski collapse lemma implies that set membership is a universal among the extensional well-founded relations: for any set-like well-founded relation ''R'' on a class ''X'' which is extensional, there exists a class ''C'' such that (''X'', ''R'') is isomorphic to (''C'', ∈).
Reflexivity
A relation ''R'' is said to be reflexive if ''a''R''a'' holds for every ''a'' in the domain of the relation. Every reflexive relation on a nonempty domain has infinite descending chains, because any constant sequence is a descending chain. For example, in the natural numbers with their usual order ≤, we have $1 \geq 1 \geq 1 \geq \cdots.$ To avoid these trivial descending sequences, when working with a partial order ≤, it is common to apply the definition of well foundedness (perhaps implicitly) to the alternate relation < defined such that ''a'' < ''b'' if and only if ''a'' ≤ ''b'' and ''a'' ≠ ''b''. More generally, when working with a preorder ≤, it is common to use the relation < defined such that ''a'' < ''b'' if and only if ''a'' ≤ ''b'' and ''b'' ≰ ''a''. In the context of the natural numbers, this means that the relation <, which is well-founded, is used instead of the relation ≤, which is not. In some texts, the definition of a well-founded relation is changed from the definition above to include these conventions.
References
* Just, Winfried and Weese, Martin (1998) ''Discovering Modern Set Theory. I'', American Mathematical Society . * Karel Hrbáček & Thomas Jech (1999) ''Introduction to Set Theory'', 3rd edition, "Well-founded relations", pages 251–5, Marcel Dekker {{ISBN|0-8247-7915-0 Category:Binary relations | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 4, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.981061577796936, "perplexity": 1076.5833513434984}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039526421.82/warc/CC-MAIN-20210421065303-20210421095303-00067.warc.gz"} |
https://socratic.org/questions/58ed71c9b72cff633c630180 | Chemistry
Topics
# Question #30180
Apr 12, 2017
X = -3
Y = +6
#### Explanation:
This is basically a math problem. Given $X {H}_{3}$ we know the valence of X must be -3 if H = +1. Then $Y {X}_{2}$ means that the valence of $Y = - 2 \cdot X$ ; $Y = 6$.
If the hydrogen ion is actually -1 instead of +1, these signs would be reversed.
##### Impact of this question
553 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 4, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9078510403633118, "perplexity": 1382.873677547644}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986669546.24/warc/CC-MAIN-20191016190431-20191016213931-00110.warc.gz"} |
https://globalbiodefense.com/2014/10/02/radiation-awareness-interdiction-network-rain/ | # Radiation Awareness and Interdiction Network ATD
The Department of Homeland Security Office of Procurement Operations (OPO), Domestic Nuclear Detection Office Acquisition Division (DNDOAD) has made the following selections for Advanced Technology Demonstration (ATD) in support of the Radiation Awareness and Interdiction Network (RAIN) program:
• Passport Systems Inc., \$6,965,865.00
• GE \$8,074,705.44
• Physical Sciences Inc. (PSI) \$6,244,636.00
The RAIN system would be composed of many potential nodes that would be deployed around a region, and provide actionable information on whether radiological or nuclear threat materials are entering or departing that region.
The overall goal of the effort is the integration of radiation detectors, ancillary sensors, image capture systems, and automated analysis and data communications capabilities to detect, localize and provide actionable information on a specific conveyance carrying radiological or nuclear threat materials. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9322926998138428, "perplexity": 9909.375935403448}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496668644.10/warc/CC-MAIN-20191115120854-20191115144854-00451.warc.gz"} |
http://www.thefullwiki.org/Deformation_(mechanics) | # Deformation (mechanics): Wikis
Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.
# Encyclopedia
Continuum mechanics
In continuum mechanics, deformation or strain is the change in the metric properties of a continuous body B in the displacement from an initial placement κ0(B) to a final placement κ(B). A change in the metric properties means that a curve drawn in the initial body placement changes its length when displaced to a curve in the final placement. If all the curves do not change length, it is said that a rigid body displacement occurred.
A strain field associated with a displacement is defined, at any point, by the change in length of the tangent vectors representing the speeds of arbitrarily parametrized curves passing through that point.
A basic geometric result, due to Fréchet, von Neumann and Jordan, states that, if the lengths of the tangent vectors fulfill the axioms of a norm and the parallelogram law, then the length of a vector is the square root of the value of the quadratic form associated, by the polarization formula, with a positive definite bilinear map called the metric tensor.
Different equivalent choices may be made for the expression of a strain field depending on whether it is defined in the initial or in the final placement and on whether the metric tensor or its dual is considered.
In a continuous body, a deformation field results from a stress field induced by applied forces or is due to changes in the temperature field inside the body. The relation between stresses and induced strains is expressed by elastic constitutive equations, e.g., Hooke's law for linear elastic materials. Deformations which are recovered after the stress field has been removed, are called elastic deformations. In this case, the continuum completely recovers its original configuration. On the other hand, irreversible deformations, which remain even after stresses have been removed, are called plastic deformations. Such deformations occur in material bodies after stresses have attained a certain threshold value known as the elastic limit or yield stress, and are the result of slip, or dislocation mechanisms at the atomic level.
Deformation is measured in units of length.
## Strain
Strain is the geometrical measure of deformation representing the relative displacement between particles in the material body. It measures how much a given displacement differs locally from a rigid-body displacement (Jacob Lubliner). Strain defines the amount of stretch or compression along a material line elements or fibers, the normal strain, and the amount of distortion associated with the sliding of plane layers over each other, the shear strain, within a deforming body (David Rees). Strain is a dimensionless quantity, which can be expressed as a decimal fraction, a percentage or in parts-per notation. This could be applied by elongation, shortening, or volume changes, or angular distortion.[1]
The state of strain at a material point of a continuum body is defined as the totality of all the changes in length of material lines or fibers, the normal strain, which pass through that point and also the totality of all the changes in the angle between pairs of lines initially perpendicular to each other, the shear strain, radiating from this point. However, it is sufficient to know the normal and shear components of strain on a set of three mutually perpendicular directions.
If there is an increase in length of the material line, the normal strain is called tensile strain, otherwise, if there is reduction or compression in the length of the material line, it is called compressive strain.
### Strain measures
Depending on the amount of strain, or local deformation, the analysis of deformation is subdivided into three deformation theories:
1. Finite strain theory, also called large strain theory, large deformation theory, deals with deformations in which both rotations and strains are arbitrarily large. In this case, the undeformed and deformed configurations of the continuum are significantly different and a clear distinction has to be made between them. This is commonly the case with elastomers, plastically-deforming materials and other fluids and biological soft tissue.
2. Infinitesimal strain theory, also called small strain theory, small deformation theory, small displacement theory, or small displacement-gradient theory where strains and rotations are both small. In this case, the undeformed and deformed configurations of the body can be assumed identical. The infinitesimal strain theory is used in the analysis of deformations of materials exhibiting elastic behavior, such as materials found in mechanical and civil engineering applications, e.g. concrete and steel.
3. Large-displacement or large-rotation theory, which assumes small strains but large rotations and displacements.
In each of these theories the strain is then defined differently. The engineering strain is the most common definition applied to materials used in mechanical and structural engineering, which are subjected to very small deformations. On the other hand, for some materials, e.g. elastomers and polymers, subjected to large deformations, the engineering definition of strain is not applicable, e.g. typical engineering strains greater than 1% (David Rees page 41), thus other more complex definitions of strain are required, such as stretch, logarithmic strain, Green strain, and Almansi strain.
The Cauchy strain or engineering strain is expressed as the ratio of total deformation to the initial dimension of the material body in which the forces are being applied. The engineering normal strain or engineering extensional strain e of a material line element or fiber axially loaded is expressed as the change in length ΔL per unit of the original length L of the line element or fibers. The normal strain is positive if the material fibers are stretched or negative if they are compressed. Thus, we have
$\ e=\frac{\Delta L}{L}=\frac{\ell -L}{L}$
where ℓ is the final length of the fiber.
The engineering shear strain is defined as the change in the angle between two material line elements initially perpendicular to each other in the undeformed or initial configuration.
The stretch ratio or extension ratio is a measure of the extensional or normal strain of a differential line element, which can be defined at either the undeformed configuration or the deformed configuration. It is defined as the ratio between the final length ℓ and the initial length L of the material line.
$\ \lambda=\frac{\ell}{L}$
The extension ratio is related to the engineering strain by
$\ e=\frac{\ell-L}{L}=\lambda-1$
This equation implies that the normal strain is zero, so that there is no deformation when the stretch is equal to unity.
The stretch ratio is used in the analysis of materials that exhibit large deformations, such as elastometers, which can sustain stretch ratios of 3 or 4 before they fail. On the other hand, traditional engineering materials, such as concrete or steel, fail at much lower stretch ratios.
The logarithmic strain ε, also called natural strain, true strain or Hencky strain. Considering an incremental strain (Ludwik)
$\ \delta \varepsilon=\frac{\delta \ell}{\ell}$
the logarithmic strain is obtained by integrating this incremental strain:
\ \begin{align} \int\delta \varepsilon &=\int_{L}^{\ell}\frac{\delta \ell}{\ell}\ \varepsilon&=\ln\left(\frac{\ell}{L}\right)=\ln \lambda \ &=\ln(1+e) \ &=e-e^2/2+e^3/3- \cdots \ \end{align}
where e is the engineering strain. The logarithmic strain provides the correct measure of the final strain when deformation takes place in a series of increments, taking into account the influence of the strain path (David Rees).
The Green strain is defined as
$\ \varepsilon_G=\frac{1}{2}\left(\frac{\ell^2-L^2}{L^2}\right)=\frac{1}{2}(\lambda^2-1)$
The Green strain is addressed in more detail in the article on finite strain theory.
The Euler-Almansi strain is defined as
$\ \varepsilon_E=\frac{1}{2}\left(\frac{\ell^2-L^2}{\ell^2}\right)=\frac{1}{2}\left(1-\frac{1}{\lambda^2}\right)$
The Euler-Almansi strain is addressed in more detail in the finite strain theory.
## Description of deformation
It is convenient to identify a reference configuration or initial geometric state of the continuum body which all subsequent configurations are referenced from. The reference configuration need not to be one the body actually will ever occupy. Often, the configuration at {nowrap|1=t = 0}} is considered the reference configuration, κ0(B). The configuration at the current time t is the current configuration.
For deformation analysis, the reference configuration is identified as undeformed configuration, and the current configuration as deformed configuration. Additionally, time is not considered when analyzing deformation, thus the sequence of configurations between the undeformed and deformed configurations are of no interest.
The components Xi of the position vector X of a particle in the reference configuration, taken with respect to the reference coordinate system, are called the material or reference coordinates. On the other hand, the components xi of the position vector x of a particle in the deformed configuration, taken with respect to the spatial coordinate system of reference, are called the spatial coordinates
There are two methods for analysing the deformation of a continuum. One description is made in terms of the material or referential coordinates, called material description or Lagrangian description. A second description is of deformation is made in terms of the spatial coordinates it is called the spatial description or Eulerian description.
There is continuity during deformation of a continuum body in the sense that:
• The material points forming a closed curve at any instant will always form a closed curve at any subsequent time.
• The material points forming a closed surface at any instant will always form a closed surface at any subsequent time and the matter within the closed surface will always remain within.
## Displacement
Figure 1. Motion of a continuum body.
A change in the configuration of a continuum body results in a displacement. The displacement of a body has two components: a rigid-body displacement and a deformation. A rigid-body displacement consist of a simultaneous translation and rotation of the body without changing its shape or size. Deformation implies the change in shape and/or size of the body from an initial or undeformed configuration $\ \kappa_0(\mathcal B)$ to a current or deformed configuration $\ \kappa_t(\mathcal B)$ (Figure 1).
If after a displacement of the continuum there is a relative displacement between particles, a deformation has occurred. On the other hand, if after displacement of the continuum the relative displacement between particles in the current configuration is zero, then there is no deformation and a rigid-body displacement is said to have occurred.
The vector joining the positions of a particle P in the undeformed configuration and deformed configuration is called the displacement vector u(X, t) = uiei in the Lagrangian description, or U(x, t) = UJEJ in the Eulerian description.
A displacement field is a vector field of all displacement vectors for all particles in the body, which relates the deformed configuration with the undeformed configuration. It is convenient to do the analysis of deformation or motion of a continuum body in terms of the displacement field, In general, the displacement field is expressed in terms of the material coordinates as
$\ \mathbf u(\mathbf X,t) = \mathbf b(\mathbf X,t)+\mathbf x(\mathbf X,t) - \mathbf X \qquad \text{or}\qquad u_i = \alpha_{iJ}b_J + x_i - \alpha_{iJ}X_J$
or in terms of the spatial coordinates as
$\ \mathbf U(\mathbf x,t) = \mathbf b(\mathbf x,t)+\mathbf x - \mathbf X(\mathbf x,t) \qquad \text{or}\qquad U_J = b_J + \alpha_{Ji}x_i - X_J \,$
where αJi are the direction cosines between the material and spatial coordinate systems with unit vectors EJ and ei, respectively. Thus
$\ \mathbf E_J \cdot \mathbf e_i = \alpha_{Ji}=\alpha_{iJ}$
and the relationship between ui and UJ is then given by
$\ u_i=\alpha_{iJ}U_J \qquad \text{or} \qquad U_J=\alpha_{Ji}u_i$
Knowing that
$\ \mathbf e_i = \alpha_{iJ}\mathbf E_J$
then
$\mathbf u(\mathbf X,t)=u_i\mathbf e_i=u_i(\alpha_{iJ}\mathbf E_J)=U_J\mathbf E_J=\mathbf U(\mathbf x,t)$
It is common to superimpose the coordinate systems for the undeformed and deformed configurations, which results in b = 0, and the direction cosines become Kronecker deltas:
$\ \mathbf E_J \cdot \mathbf e_i = \delta_{Ji}=\delta_{iJ}.$
Thus, we have
$\ \mathbf u(\mathbf X,t) = \mathbf x(\mathbf X,t) - \mathbf X \qquad \text{or}\qquad u_i = x_i - \delta_{iJ}X_J = x_i - X_i$
or in terms of the spatial coordinates as
$\ \mathbf U(\mathbf x,t) = \mathbf x - \mathbf X(\mathbf x,t) \qquad \text{or}\qquad U_J = \delta_{Ji}x_i - X_J =x_J - X_J$
The partial differentiation of the displacement vector with respect to the material coordinates yields the material displacement gradient tensor $\ \mathbf u\nabla_{\mathbf X}$. Thus we have:
\ \begin{align} \mathbf u(\mathbf X,t) &= \mathbf x(\mathbf X,t) - \mathbf X \ \mathbf u\nabla_{\mathbf X} &= \mathbf x\nabla_{\mathbf X} - \mathbf I \ \mathbf u\nabla_{\mathbf X} &= \mathbf F - \mathbf I \ \end{align} \qquad \text{or} \qquad \begin{align} u_i& = x_i-\delta_{iJ}X_J = x_i - X_i\ \frac{\partial u_i}{\partial X_K}&=\frac{\partial x_i}{\partial X_K}-\delta_{iK} \ \end{align}
where $\ \mathbf F$ is the deformation gradient tensor.
Similarly, the partial differentiation of the displacement vector with respect to the spatial coordinates yields the spatial displacement gradient tensor $\ \mathbf U\nabla_{\mathbf x}$. Thus we have,
\ \begin{align} \mathbf U(\mathbf x,t) &= \mathbf x - \mathbf X(\mathbf x,t) \ \mathbf U\nabla_{\mathbf x} &= \mathbf I - \mathbf X\nabla_{\mathbf X} \ \mathbf U\nabla_{\mathbf x} &= \mathbf I -\mathbf F^{-1}\ \end{align} \qquad \text{or} \qquad \begin{align} U_J& = \delta_{Ji}x_i-X_J =x_J - X_J\ \frac{\partial U_J}{\partial x_k} &= \delta_{Jk}-\frac{\partial X_J}{\partial x_k}\ \end{align}
## References
1. ^ "Earth."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD .[2009]. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 23, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9712544679641724, "perplexity": 773.9176850148051}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257648594.80/warc/CC-MAIN-20180323200519-20180323220519-00002.warc.gz"} |
https://torchdrug.ai/docs/notes/variadic.html | # Batch Irregular Structures¶
Unlike images, text and audio, graphs usually have irregular structures, which makes them hard to batch in tensor frameworks. Many existing implementations use padding to convert graphs into dense grid structures, which costs much unnecessary computation and memory.
In TorchDrug, we develop a more intuitive and efficient solution based on variadic functions. The variadic functions can directly operate on sparse irregular inputs or outputs.
Here we show how to apply functions to variadic inputs.
Generally, a batch of $$n$$ variadic tensors can be represented by a value tensor and a size tensor. The value tensor is a concatenation of all variadic tensors along the variadic axis, while the size tensor indicates how big each variadic tensor is.
Let’s first create a batch of 1D variadic samples.
import torch
samples = []
for size in range(2, 6):
samples.append(torch.randint(6, (size,)))
value = torch.cat(samples)
size = torch.tensor([len(s) for s in samples])
We apply variadic functions to compute the sum, max and top-k values for each sample.
from torchdrug.layers import functional
sum = functional.variadic_sum(value, size)
max = functional.variadic_max(value, size)[0]
top3_value, top3_index = functional.variadic_topk(value, size, k=3)
Note variadic_topk accepts samples smaller than $$k$$. In this case, it will fill the output with the smallest element from that sample.
Mathematically, these functions can be viewed as performing the operation over each sample with a for loop. For example, the variadic sum is equivalent to the following logic.
sums = []
for sample in samples:
sums.append(sample.sum())
sum = torch.cat(sums)
Note
In spite of the same logic, variadic functions is much faster than for loops on GPUs (typically $$\text{batch size}\times$$ faster). Use variadic functions instead of for loops whenever possible.
Many operations in graph representation learning can be implemented by variadic functions. For example,
1. Infer graph-level representations from node-/edge-level representations.
2. Perform classification over nodes/edges.
Here we demonstrate how to perform classification over nodes. We create a toy task, where the model needs to predict the heaviest atom of each molecule. Note that node attributes form variadic tensors with num_nodes from the same graph. Therefore, we can use variadic_max to get our ground truth.
from torchdrug import data, models, metrics
smiles_list = ["CC(=C)C#N", "CCNC(=S)NCC", "BrC1=CC=C(Br)C=C1"]
graph = data.PackedMolecule.from_smiles(smiles_list)
target = functional.variadic_max(graph.atom_type, graph.num_nodes)[1]
Naturally, the prediction over nodes also forms a variadic tensor with num_nodes.
model = models.GCN(input_dim=graph.node_feature.shape[-1], hidden_dims=[128, 128, 1])
feature = model(graph, graph.node_feature.float())
pred = feature["node_feature"].squeeze(-1)
pred_prob, pred_index = functional.variadic_max(pred, graph.num_nodes)
loss = functional.variadic_cross_entropy(pred, target, graph.num_nodes)
accuracy = metrics.variadic_accuracy(pred, target, graph.num_nodes)
In some cases, we also need to write functions that produce variadic outputs. A typical example is autoregressive generation, where we need to generate all node/edge prefixes of a graph. When this operation is batched, we need to output variadic numbers of graphs for different input graphs.
Here we show how to generate edge prefixes for a batch of graphs in TorchDrug. First, let’s prepare a batch of two graphs.
edge_list = [[0, 1], [1, 2], [2, 3], [3, 4], [4, 5]]
graph1 = data.Graph(edge_list, num_node=6)
edge_list = [[0, 1], [1, 2], [2, 3], [3, 0], [0, 2], [1, 3]]
graph2 = data.Graph(edge_list, num_node=4)
graph = data.Graph.pack([graph1, graph2])
with graph.graph():
graph.id = torch.arange(2)
The generation of edge prefixes consists 3 steps.
1. Construct an extended batch with enough copies for each graph.
2. Apply an edge mask over the batch.
3. Remove excess or invalid graphs.
The first step can be implemented through Graph.repeat. For the following steps, we define an auxiliary function all_prefix_slice. This function takes in a size tensor and desired prefix lengths, and outputs $$n*l$$ prefix slices for the extended batch, where $$n$$ is the batch size and $$l$$ is the number of prefix lengths.
def all_prefix_slice(size, lengths=None):
cum_sizes = sizes.cumsum(0)
starts = cum_sizes - sizes
if lengths is None:
max_size = sizes.max().item()
lengths = torch.arange(0, max_size, 1, device=sizes.device)
pack_offsets = torch.arange(len(lengths), device=sizes.device) * num_cum_xs[-1]
starts = starts.unsqueeze(0) + pack_offsets.unsqueeze(-1)
valid = lengths.unsqueeze(-1) <= sizes.unsqueeze(0)
lengths = torch.min(lengths.unsqueeze(-1), sizes.unsqueeze(0)).clamp(0)
ends = starts + lengths
starts = starts.flatten()
ends = ends.flatten()
valid = valid.flatten()
return starts, ends, valid
lengths = torch.arange(1, graph.num_edges.max() + 1)
num_length = len(lengths)
starts, ends, valid = all_prefix_slice(graph.num_edges, lengths)
The slices are visualized as follows. Two colors correspond to two input graphs.
graph = graph.repeat(num_length) # step 1 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5221607685089111, "perplexity": 4858.30329369753}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304872.21/warc/CC-MAIN-20220125190255-20220125220255-00141.warc.gz"} |
http://forums.parallax.com/discussion/comment/1481311/ | Welcome to the Parallax Discussion Forums, sign-up to participate.
# P2 Tricks, Traps & Differences between P1 (general discussion)
• Posts: 12,153
Thanks, Guys. I've got it now.
• Posts: 15,661
SKIPF and SKIP
Special SKIPF Branching Rules
From the manual...
Within SKIPF sequences where CALL/CALLPA/CALLPB are used to execute subroutines in which skipping will be suspended until after RET, all CALL/CALLPA/CALLPB immediate branch addresses must be absolute in cases where the instruction after the CALL/CALLPA/CALLPB might be skipped. This is not possible for CALLPA/CALLPB but CALL can use '#\address' syntax to achieve absolute immediate addressing. CALL/CALLPA/CALLPB can all use registers as branch addresses, since they are absolute.
For non-CALL\CALLPA\CALLPB branches within SKIPF sequences, SKIPF will work through all immediate-relative branches, which are the default for immediate branches within cog/LUT memory. If an absolute-address branch is being used (#\label, register, or RET, for example), you must not skip the first instruction after the branch. This is not a problem with immediate-relative branches, however, since the variable PC stepping works to advantage, by landing the PC at the first instruction of interest at, or beyond, the branch address.
Today I was testing to see if I could nest subroutines while keeping the skip in place for return.
Here is what I found (only tested in COG)...
* SKIPF fails if the CALL is relative and the next instruction is to be skipped
* SKIP works correctly even if the call is relative (at least my test did)
* SKIPF and SKIP both work correctly if the call is absolute (ie #\label)
* When it works, 2 level nesting works (ie the CALLed routine makes another CALL.
Here is an extract of the code I used
000d8 036 00 C0 07 F6 | mov lmm_x, #0
000dc 037 32 18 64 FD | skipf #%0000_1100 ' SKIPF result is $0000_0C31 - WRONG!!! 000e0 038 | ' skip #%0000_1100 ' SKIP result is$0000_FE31 - correct
000e0 038 01 C0 47 F5 | or lmm_x, #%0000_0001 ' xxxx xxxx xxx0
000e4 039 1C 00 B0 FD | call #sr1 ' xxxx xxxx xx0x
000e8 03a 04 C0 47 F5 | or lmm_x, #%0000_0100 ' xxxx xxxx x1xx skip
000ec 03b 08 C0 47 F5 | or lmm_x, #%0000_1000 ' xxxx xxxx 1xxx skip
000f0 03c 10 C0 47 F5 | or lmm_x, #%0001_0000 ' xxxx xxx0 xxxx
000f4 03d 20 C0 47 F5 | or lmm_x, #%0010_0000 ' xxxx xx0x xxxx
000f8 03e |
000f8 03e 28 CB AF FD | call #_hubHex8
000fc 03f E4 CA AF FD | call #_hubTxCR
00100 040 78 CD 8F FD | jmp #_hubMonitor
00104 041 |
00104 041 | sr1
00104 041 1C 00 B0 FD | call #sr2 '\ gets skipped if SKIPF and CALL #sr1 is relative
00108 042 01 00 00 FF
0010c 043 00 C0 47 F5 | or lmm_x, ##%0010_0000_0000 '/ gets skipped if SKIPF and CALL #sr1 is relative
00110 044 02 00 00 FF
00114 045 00 C0 47 F5 | or lmm_x, ##%0100_0000_0000
00118 046 04 00 00 FF
0011c 047 00 C0 47 F5 | or lmm_x, ##%1000_0000_0000
00120 048 2D 00 64 FD | ret
00124 049 |
00124 049 | sr2 or lmm_x, ##%0001_0000_0000_0000
00124 049 08 00 00 FF
00128 04a 00 C0 47 F5
0012c 04b 10 00 00 FF
00130 04c 00 C0 47 F5 | or lmm_x, ##%0010_0000_0000_0000
00134 04d 20 00 00 FF
00138 04e 00 C0 47 F5 | or lmm_x, ##%0100_0000_0000_0000
0013c 04f 40 00 00 FF
00140 050 00 C0 47 F5 | or lmm_x, ##%1000_0000_0000_0000
00144 051 2D 00 64 FD | ret
00148 052 |
00148 052 | ' SKIPF result is $0000_0C31 00148 052 | ' SKIP result is$0000_FE31 - correct
000e4 039 41 00 A0 FD | call #\sr1 ' xxxx xxxx xx0x 'SKIPF result is 0000_FE31 - correct My Prop boards: P8XBlade2 , RamBlade , CpuBlade , TriBlade P1 Prop OS (also see Sphinx, PropDos, PropCmd, Spinix) Website: www.clusos.com • Posts: 8,601 edited 2019-10-08 - 10:55:27 I think I've found a useful trick when using PTRA/B operations. It's a little specialised but I'm sure it can be repurposed in other ways. The trick is the POP'd C/Z flags within the PTRA register are preserved across its operational use. '=============================================== 'Emit string from immediate code in hubRAM ' input: (hardware call stack) - hubRAM address of string ' result: (none) 'scratch: pb, temp1 ' putsi mov temp1, ptra 'preserve existing PTRA pop ptra 'address of immediate data following the CALL (includes the calling C/Z flags) .loop rdbyte pb, ptra++ wz 'get next charater, Z sets with null termination if_nz call #putch 'emit character if_nz jmp #.loop push ptra 'update return address to instruction following the null character mov ptra, temp1 'restore prior PTRA ret wcz 'calling C/Z preserved "Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988. • Posts: 8,601 edited 2019-10-15 - 00:26:59 I've been getting myself in trouble with concurrent cordic ops. It's quite cool firing it off and coming back later to collect the results ... but, if for example I add in some debug type code, I find I'm breaking things too easy now because all my decimal printing is using the cordic divide operation. So my first step to tidying this up a little is to at least make the printing routines themselves reliable in this scenario. The trick here is how to know you are getting the newest result - from print's QDIV operation. A little experimenting later and two instructions does it, eg: emitclkfrq qdiv clk_freq, ##1_000_000 pollqmt 'clear old event .flushloop getqx pa 'MHz whole number - at final pipeline result jnqmt #.flushloop 'wait for QMT flag - CORDIC pipeline flushed getqy temp2 'six decimal places ... EDIT: PS: I fixed me problem. It was a bug, I wasn't clearing the event flag before using. I keep forgetting that the things that set the event flags, don't reset them. EDIT2: It's in contrast to the straight through code that assumes the pipeline is empty prior to routine call. Which would be coded like this instead: emitclkfrq qdiv clk_freq, ##1_000_000 getqx pa 'MHz whole number getqy temp2 'six decimal places ... My first attempt was to check before use, but that immediately annoyed me as bloaty code. eg: emitclkfrq pollqmt 'clear old event .flushloop getqx inb jnqmt #.flushloop 'wait for QMT flag - CORDIC pipeline flushed qdiv clk_freq, ##1_000_000 getqx pa 'MHz whole number - at final pipeline result getqy temp2 'six decimal places ... "Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988. • Posts: 15,661 evanh wrote: » I think I've found a useful trick when using PTRA/B operations. It's a little specialised but I'm sure it can be repurposed in other ways. The trick is the POP'd C/Z flags within the PTRA register are preserved across its operational use. '=============================================== 'Emit string from immediate code in hubRAM ' input: (hardware call stack) - hubRAM address of string ' result: (none) 'scratch: pb, temp1 ' putsi mov temp1, ptra 'preserve existing PTRA pop ptra 'address of immediate data following the CALL (includes the calling C/Z flags) .loop rdbyte pb, ptra++ wz 'get next charater, Z sets with null termination if_nz call #putch 'emit character if_nz jmp #.loop push ptra 'update return address to instruction following the null character mov ptra, temp1 'restore prior PTRA ret wcz 'calling C/Z preserved Interesting. Because PTRA++ only increments the lower 20 bits, and the upper bits remain unchanged. Certainly a nice way to pass parameters. My Prop boards: P8XBlade2 , RamBlade , CpuBlade , TriBlade P1 Prop OS (also see Sphinx, PropDos, PropCmd, Spinix) Website: www.clusos.com • Posts: 8,601 edited 2019-10-29 - 11:15:45 A trap with the smartpin pulse out modes: This applies to pulse %00100 and transition %00101 out modes at least. Presumably also applies to all DAC, NCO and PWM modes as well. It really only affects pulse and transition modes though because they have an end count of pulses. The "base period" is a metronomic clock from when the smartpin mode is first configured. This stays actively ticking within the smartpin even if the smartpin is not generating pulses. EDIT: What this means is that when WYPIN issues more pulses to generate, the smartpin is not instruction aligned but rather will start the pulse generation at the beginning of the next base period. Most of the time this detail can be ignored. But I've been playing around with aligning a streamer bursting of SPI data out to coincide with a smartpin emulating a SPI clock. This means, because of the base period effect, the SPI clock pin will then have an unpleasant alignment dither with respect to the SPI data pin if the smartpin is not reconfigured for each burst. A disable/enable combo is not enough. PS: It maybe possible to give the streamer the same "base period" and using XCONT instead of XINIT for each burst to duplicate the smartpin's behaviour. Not something I've tried out yet ... PPS: Correction: Along with a compensation, clearing out the chaff allowed a DIRL+DIRH combo on the SPI clock smartpin to do the job. XCONT wasn't the answer. "Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988. • Posts: 1,773 edited 2019-10-29 - 05:20:25 Just found something weird in testing some video driver code and hitting a bug I had to solve which took me a while. When you copy ptrb to ptra the upper bits in ptra are somehow lost/trashed. This code fails: mov ptra, ptrb 'make a copy to preserve things ... getnib a, ptra, #5 'extract pin group which behaves differently to this code below, which works. mov pb, ptrb 'make a copy to preserve things ... getnib a, pb, #5 'extract pin group The snipped ... code in the middle is innocuous and doesn't ever access ptra. • Posts: 8,601 rogloh wrote: » When you copy ptrb to ptra the upper bits in ptra are somehow lost/trashed. This code fails: mov ptra, ptrb 'make a copy to preserve things ... getnib a, ptra, #5 'extract pin group Not seeing that here. Here's my test code: mov bcdlen, #8 mov count, #10 .loop getrnd ptrb mov ptra, ptrb getnib pa, ptra, #5 call #itoh call #putsp mov pa, ptra call #itoh call #putsp mov pa, ptrb call #itoh call #putsp getnib pa, ptrb, #5 call #itoh call #putnl djnz count, #.loop jmp #
and output:
00000003 aa30f2d5 aa30f2d5 00000003
00000006 c865965d c865965d 00000006
00000000 9704b86f 9704b86f 00000000
00000002 ac2d8dcd ac2d8dcd 00000002
0000000c bdc56ccd bdc56ccd 0000000c
0000000f a8fcdcb5 a8fcdcb5 0000000f
00000001 131cc72a 131cc72a 00000001
00000006 e9611c4d e9611c4d 00000006
0000000e 49e2fc62 49e2fc62 0000000e
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 1,773
Well it definitely happens to me.
I removed all code in the ... part to rule anything else out.
This works fine:
mov pb, ptrb 'make a copy to preserve things
getnib a, pb, #5 'extract pin group
This does not
mov ptra, ptrb 'make a copy to preserve things
getnib a, ptra, #5 'extract pin group
neither does this...
getnib a, ptrb, #5 'extract pin group
Next time ptra gets accessed later in my code it is overwritten with a new value anyway so leaving residual data in it is not causing problems.. And it doesn't have to using be the pb register to somehow inadvertently make it work, other general registers work too instead of pb. It just seems using ptra or ptrb doesn't work here with getting upper nibbles, somehow the upper bits get lost. I thought these registers were meant to still be 32 bits.
ps. I am executing this code from LUT RAM in case that could possibly make any difference...?
• Posts: 8,601
Lutexec is fine for me.
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 1,773
Are you using rev A or rev B?
• Posts: 8,601
edited 2019-10-29 - 08:43:12
revB at the moment. After earlier confusions with revA vs revB vs FPGA I have it list a few crucial detected parameters on each run. First text emitted of all recent runs:
Total smartpins = 64 1111111111111111111111111111111111111111111111111111111111111111
Rev B silicon. Sysclock 4.0000 MHz
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 2,612
Not seeing fault here either Roger.
Might be worth checking compiler output.
I'm running Pnut and I think evan runs fastspin?
Melbourne, Australia
• Posts: 1,773
I am running P2ASM and I have been overclocking somewhat in the 252-308MHz range. I'll check the P2ASM output to make sure it is not generating bad opcodes.
• Posts: 8,601
Yes, I'm using fastspin almost exclusively these days. I tested mine up to 395 MHz without issue. No issue with the data values at 400 MHz but it does crash as expected on repeated runs.
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 1,773
edited 2019-10-29 - 09:58:52
00910 303 f603f1f9 mov ptra, ptrb 'make a copy to preserve things
0094c 312 f86f1500 getnib a, ptra, #5 'extract pin group
Good:
00910 303 f603eff9 mov pb, ptrb 'make a copy to preserve things
0094c 312 f86b15f7 getnib a, pb, #5 'extract pin group
The S address in "getnib a, ptra, #5" looks a bit weird if it's \$100. Seems bad and almost like it's using the GETNIB D form, but not quite.
Seems this is a bug in P2ASM @Dave Hein are you still doing bug fixes? Actually I am running v0.016. I'd better check I'm up to the latest.
https://github.com/davehein/p2gcc/blob/master/p2asm_src/p2asm.c
• Posts: 5,982
edited 2019-10-29 - 13:56:19
I think this bug has been in p2asm from the beginning. If the source is ptra or ptrb p2asm will generate the pointer encoding instead of just using the pointer cog memory location. This affects getnib, rolnib, getbyte, rolbyte, getword and rolword. I'll fix it in GitHub in the next few minutes.
EDIT: This is now fixed in version 0.017.
• Posts: 4,505
Dave Hein wrote: »
I think this bug has been in p2asm from the beginning. If the source is ptra or ptrb p2asm will generate the pointer encoding instead of just using the pointer cog memory location. This affects getnib, rolnib, getbyte, rolbyte, getword and rolword. I'll fix it in GitHub in the next few minutes.
EDIT: This is now fixed in version 0.017.
Serves me right for not keeping up to date
Catalina - a FREE ANSI C compiler for the Propeller.
• Posts: 8,601
edited 2019-10-31 - 14:08:43
Is anyone supporting programming of the boot Flash EEPROM on board the Eval boards in their tools? Cluso, Chip, and Peter I think, worked out a pinout convention for having both SD and SPI bootable components on same four pins, P58-61. Chip has them documented in the prop2 doc. I presume Peter also uses same pinout for P2D2 boards.
PS: I've had very good success in tuning up Brian's demo code to make the booting very fast even for large binaries - https://forums.parallax.com/discussion/comment/1480866/#Comment_1480866
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 15,661
While the P2 can boot from Serial/FLASH/SD I am not aware if any downloaders are capable of writing to FLASH or SD currently.
P1 Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
Website: www.clusos.com
• Posts: 3,809
loadp2 doesn't currently support programming the flash, but If there's some stand-alone code for programming the flash it should be fairly straightforward to incorporate that.
FlexGUI, a GUI for programming the P1 and P2 in Spin, PASM, BASIC, and C.
Help support its development at Patreon or PayPal.
• Posts: 1,773
Cluso99 wrote: »
While the P2 can boot from Serial/FLASH/SD I am not aware if any downloaders are capable of writing to FLASH or SD currently.
Cluso, were any of your ROM based SD init & write sector routines made available in a callable manner? If so it might be more straightforward to load and run some very small SD downloader PASM into the P2 somewhat like it did with its MainLoader1.spin that can access these routines and then we can write directly to a file, instead of developing an entire SD handling object first before that will be possible.
I know we can yank the SD card and write it in a PC etc, but on the P2-EVAL getting the microSD in and out becomes a chore fast and is not that ideal during development. I think there are some extender cards available that would help with that.
• Posts: 4,505
Catalina has a command that can program any .bin file into the FLASH RAM on the P2 EVAL board. It uses a version of the Flash_Loader_1.2 by ozpropdev.
Catalina - a FREE ANSI C compiler for the Propeller.
• Posts: 8,601
edited 2019-11-01 - 00:29:36
RossH wrote: »
Catalina has a command that can program any .bin file into the FLASH RAM on the P2 EVAL board. It uses a version of the Flash_Loader_1.2 by ozpropdev.
Good to hear. That should make it easy to integrate what I've done with speeding up the booting loader code.
I did also rework Brian's low-level serial programming routines but all that can be ignored. It was from when I was trying to figure out why nothing was working on the revB Eval board. Turns out I had a non-soldered CS pin on the Flash chip.
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 8,601
ersmith wrote: »
loadp2 doesn't currently support programming the flash, but If there's some stand-alone code for programming the flash it should be fairly straightforward to incorporate that.
Ah, just noticed this as a request. Oz posted this a while back - https://forums.parallax.com/discussion/169608/prop2-flash-loader/p1
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 8,601
Cluso,
Oh, that's not working for me - https://forums.parallax.com/discussion/comment/1482105/#Comment_1482105
You've got three types of "try"s. A column, 3 lines, and individual grid entries. What's the differences?
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 15,661
Follow down left column as code executes...
So from Reset, the code tests for PU on P59, and if yes, Try will "try Serial", and if it fails else it will go on to "try FLASH" in the first column
Next "try FLASH", the code tests for PU on P61, and if yes, Try will "try FLASH", and if successful will load/run FLASH, else, will go on to "try SD" in the first column
Next "try SD", the code tests for PU on P60, and if yes, Try will "try SD", and if successful will load/run SD, else, will go on the "try Serial" in the first column
Next, "try Serial", the code tests for PD on P59, and if yes, Try, will "STOP", else will wait for "SERIAL" (after timeout will STOP IIRC)
Certainly could be expressed better - I did it in a hurry to see what pullups and pulldowns I need on a pcb.
P1 Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
Website: www.clusos.com
• Posts: 8,601
Hmm, I'll add that Chip has six boot combinations listed in the google doc and, of the four boot lines you've got there, the first two, "Reset..." and "try FLASH..." are definitely wrong.
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988.
• Posts: 8,853
edited 2019-11-20 - 04:45:18
P59 PD was specifically to disable serial boot altogether. So saying STOP is appropriate in this case.
Boot ROM code execution is in this order:
P59 PU - TRY SERIAL
P61 PU - TRY FLASH
P60 PU - TRY SD
P59 PD - IGNORE SERIAL
To force it to check serial first before anything else after reset you would add a pull-up to P59. ( Cluso99's "flow" table is correct )
If I wanted it to always check Flash first then I would have a pull-up on the Flash CS
If an SD card is inserted then it detected as a pull-up on its CS = P60 and initializing the card can take many 100's of milliseconds. (don't use an external PU)
So with a Flash in the system you would tend to have a PU on its CS so it would get checked first.
If the Flash didn't have valid boot code then it would check the SD card as long as there is one inserted.
Finally it would check serial as long as there isn't a PD there.
Tachyon Forth - compact, fast, forthwright and interactive
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• Posts: 8,601
Here's the table from the prop2 google doc
1110 x 769 - 93K
"Those who think we are powerless to do anything about the greenhouse effect forget about the 'White House effect,'" - George H.W. Bush, 1988. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2715790271759033, "perplexity": 14039.739430018475}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250605075.24/warc/CC-MAIN-20200121192553-20200121221553-00389.warc.gz"} |
http://codeforces.com/blog/entry/66689 | ### VerbalKint's blog
By VerbalKint, history, 5 weeks ago, ,
I was solving this problem: https://www.spoj.com/problems/BREAK/ I figured that for a DAG, we can solve it by using indegree vector and simple dfs. Going though some online editorials, I noticed that there was mention of Strongly Connected Components. Can anyone tell me the intuition behind using SCC in this question. Any help is appreciated. Thanks
•
• -2
•
» 5 weeks ago, # | 0 Well, in SCC we can reach any node to another. So, if the graph is SCC then answer is obviously $N$ for each number. Moreover, you can make a DAG with considering this SCC's as a vertex. You know how to solve it for DAG, so you only need to apply there and make correct calculations.
• » » 4 weeks ago, # ^ | 0 Thanks. I got the idea behind using SCC in this question,
» 4 weeks ago, # | 0 The idea behind SCCs is, that you can create a DAG from any arbitrary graph by contracting each SCC into a single node. The resulting graph is called "condensation graph", and is guaranteed to be a DAG. This is also fine, since the number of nodes every node in a SCC can reach is equal.Why does having a DAG helps? Quite a bunch of problems can be solved efficiently on DAGs using DP. E.g. most of the game theory problems are based on that. However you can't apply DP on that problem. A first idea would be the recursion $f(v) = 1 + \sum_{(v, u) \in E} f(u)$, where $f(v)$ counts the number of reachable vertices from $v$. However it doesn't work because you double count vertices. E.g. look at the following graph and compute $f(1)$: 1->2 | | v v 3->4So even if you have a DAG, you need to do the trivial approach by running a DFS from each nodes, resulting in a runtime of $O(n m)$. And you can do that also on the normal graph in the same time complexity.So does SCC help at all? Yes, because the test cases are not very good. I just tried to submit a solution without SCC, and it TLEd. And a solution with SCC got AC. On a random graph the condensation graph is usually a lot smaller than the original graph, which gives a decent performance boost (you only need to do one DFS for each SCC, instead one for each node, have less nodes and edges in general, ...). However it is possible to create graphs with $\Theta(n^2)$ edges, which correspond to their condensation graphs. In such a case you have a big graph, and computing the SCCs and the condensation graph will do nothing at all.Note: it is possible to compute the answer faster than $O(n m)$. One method is to compute the transitive closure of the graph using matrix exponentiation. You can see in $A^n$ which vertex is reachable from which one, where $A$ is the adjacency matrix. Using binary exponantiation you can copmute $A^n$ in $O(n^3 \log n)$ time. If you use a faster matrix multiplication algorithm you can reduce the $n^3$ factor, and this pdf describes a way of getting rid of the logarithmic factor by first computing the condensation graph. However I doubt that such an approach can get the problem accepted.
• » » 4 weeks ago, # ^ | 0 Thanks a lot for the explanation. I also got TLE without SCC. I learned something new from this question. I'll try to solve more SCC problems now. Thanks again :) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7772985100746155, "perplexity": 372.8306108611226}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232258439.57/warc/CC-MAIN-20190525184948-20190525210948-00275.warc.gz"} |
https://science.sciencemag.org/content/251/4997/1054 | Reports
# Reduction of Deepwater Formation in the Greenland Sea During the 1980s: Evidence from Tracer Data
See allHide authors and affiliations
Science 01 Mar 1991:
Vol. 251, Issue 4997, pp. 1054-1056
DOI: 10.1126/science.251.4997.1054
## Abstract
Hydrographic observations and measurements of the concentrations of chlorofluorocarbons (CFCs) have suggested that the formation of Greenland Sea Deep Water (GSDW) slowed down considerably during the 1980s. Such a decrease is related to weakened convection in the Greenland Sea and thus could have significant impact on the properties of the waters flowing over the Scotland-Iceland-Greenland ridge system into the deep Atlantic. Study of the variability of GSDW formation is relevant for understanding the impact of the circulation in the European Polar seas on regional and global deep water characteristics. New long-term multitracer observations from the Greenland Sea show that GSDW formation indeed was greatly reduced during the 1980s. A box model of deepwater formation and exchange in the European Polar seas tuned by the tracer data indicates that the reduction rate of GSDW formation was about 80 percent and that the start date of the reduction was between 1978 and 1982. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9352463483810425, "perplexity": 3061.6375521882082}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195528141.87/warc/CC-MAIN-20190722154408-20190722180408-00483.warc.gz"} |
https://www.physicsforums.com/threads/real-analysis-convergence-l-u-b.184096/ | # Real analysis- Convergence/l.u.b
1. Sep 11, 2007
### Scousergirl
I'm having a little difficulty understanding Epsilon in the definition of convergence. From what the book says it is any small real number greater than zero (as small as you can imagine???). Also, since I don't quite grasp what this epsilon is and how it helps define convergence, I am having difficulty applying it to the following problem:
Let b=Least upper bound of a set S (S is a subset of the real numbers) that is bounded and non empty. Then Given epsilon greater than 0, there exists an s in S such that (b-Epsilon)<= s <= b.
I started by proving that there exists an s in S, but I cannot figure out how to relate this all to epsilon. What is confusing me I guess is the actual definition of S. Can the set {1*, b} satisfy the requirements of s (it is a subset of the real numbers, bounded above by b and non empty) but then how do we show that the statement is true for s=1*. Also, b doesn't have to part of S right?
Last edited: Sep 11, 2007
2. Sep 11, 2007
### Dick
A bounded set has many upper bounds. The least upper bound b is the one that is low enough that if you pick any number less than b (b-Epsilon) no matter how small the Epsilon, then that number is not an upper bound. And yes, b doesn't have to be in S. After that, you confuse me. What's 1*?
3. Sep 11, 2007
### Scousergirl
Ok, I think I understand the least upper bound part of the question, I just don't know how to go about proving that ANY subset of the real numbers (S) that is non empty and bounded above by b must contain an element s such that (b-epsilon)<= s <= b.
1* is a dedekind cut (the real number 1 basically). Doesn't a set say S={1 , b} satisfy these conditions yet if I choose a small epsilon, 1 is not neccesarily greater or equal to (b-epsilon).
4. Sep 11, 2007
### Dick
Mmm. That's the DEFINITION of least upper bound. I.e. it's the definition of 'b'. You don't have to prove there is such an s. If b is least upper bound of S there is such an s for every epsilon. Otherwise it's not a least upper bound. A dedekind cut is two subsets of the rationals with special properties. Neither subset is even bounded. The least upper bound of S={1,b} is 1 if b>1 and b if b<1. I think this concept is much less complicated than you think it is.
5. Sep 11, 2007
### Scousergirl
hmmm...I think maybe I am confusing multiple concepts here. The question that I am having difficulty with is how to prove that such an s exists for all subsets of the real numbers. (b-epsilon)<= s <= b.
I tried tackling it by contradiction:
Assume there does not exist an s in S such that (b-epsilon)<= s. Thus for all s in S, s< (b-epsilon). Is this a contradiction to the fact that b is the least upper bound of S?
6. Sep 11, 2007
### Dick
Such an s does not exist for all subsets of the real numbers. Some aren't bounded. So there is no b. On the other hand for this "Assume there does not exist an s in S such that (b-epsilon)<= s. Thus for all s in S, s< (b-epsilon). Is this a contradiction to the fact that b is the least upper bound of S?". Yes, that contradicts b being least upper bound. But this is getting really confusing for me as well as for you, it's getting existential. Try dealing with well defined subsets of the reals and figuring out what the least upper bound is and what it means. It sounds much more confusing in the abstract than what it really is. Trust me.
Similar Discussions: Real analysis- Convergence/l.u.b | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9730895161628723, "perplexity": 308.515838539825}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818696681.94/warc/CC-MAIN-20170926193955-20170926213955-00524.warc.gz"} |
https://deepai.org/publication/a-linear-time-n-0-4-approximation-for-longest-common-subsequence | A Linear-Time n^0.4-Approximation for Longest Common Subsequence
We consider the classic problem of computing the Longest Common Subsequence (LCS) of two strings of length n. While a simple quadratic algorithm has been known for the problem for more than 40 years, no faster algorithm has been found despite an extensive effort. The lack of progress on the problem has recently been explained by Abboud, Backurs, and Vassilevska Williams [FOCS'15] and Bringmann and Künnemann [FOCS'15] who proved that there is no subquadratic algorithm unless the Strong Exponential Time Hypothesis fails. This has led the community to look for subquadratic approximation algorithms for the problem. Yet, unlike the edit distance problem for which a constant-factor approximation in almost-linear time is known, very little progress has been made on LCS, making it a notoriously difficult problem also in the realm of approximation. For the general setting, only a naive O(n^ε/2)-approximation algorithm with running time Õ(n^2-ε) has been known, for any constant 0 < ε≤ 1. Recently, a breakthrough result by Hajiaghayi, Seddighin, Seddighin, and Sun [SODA'19] provided a linear-time algorithm that yields a O(n^0.497956)-approximation in expectation; improving upon the naive O(√(n))-approximation for the first time. In this paper, we provide an algorithm that in time O(n^2-ε) computes an Õ(n^2ε/5)-approximation with high probability, for any 0 < ε≤ 1. Our result (1) gives an Õ(n^0.4)-approximation in linear time, improving upon the bound of Hajiaghayi, Seddighin, Seddighin, and Sun, (2) provides an algorithm whose approximation scales with any subquadratic running time O(n^2-ε), improving upon the naive bound of O(n^ε/2) for any ε, and (3) instead of only in expectation, succeeds with high probability.
Authors
• 35 publications
• 28 publications
• 12 publications
12/15/2021
Approximating the Longest Common Subsequence problem within a sub-polynomial factor in linear time
The Longest Common Subsequence (LCS) of two strings is a fundamental str...
12/22/2017
Longest common substring with approximately k mismatches
In the longest common substring problem we are given two strings of leng...
02/24/2020
Upper Tail Analysis of Bucket Sort and Random Tries
Bucket Sort is known to run in expected linear time when the input keys ...
03/16/2020
Approximating LCS in Linear Time: Beating the √(n) Barrier
Longest common subsequence (LCS) is one of the most fundamental problems...
05/07/2021
Improved Approximation for Longest Common Subsequence over Small Alphabets
This paper investigates the approximability of the Longest Common Subseq...
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How Packed Is It, Really?
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Longest Increasing Subsequence under Persistent Comparison Errors
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1 Introduction
The longest common subsequence (LCS) of two strings and is the longest string that appears as a subsequence of both strings. The length of the LCS of and , which we denote by , is one of the most fundamental measures of similarity between two strings and has drawn significant interest in last five decades, see, e.g. [35, 6, 26, 27, 30, 32, 10, 31, 11, 36, 22, 16, 28, 2, 19, 4, 20, 3, 33, 34, 24]. On strings of length , the LCS problem can be solved exactly in quadratic time using a classical dynamic programming approach [35]. Despite an extensive line of research the quadratic running time has been improved only by logarithmic factors [30]. This lack of progress is explained by a recent result showing that any truly subquadratic algorithm for LCS would falsify the Strong Exponential Time Hypothesis (SETH); this has been proven independently by Abboud et al. [2] and by Bringmann and Künnemann [19]. Further work in this direction shows that even a high polylogarithmic speedup for LCS would have surprising consequences [4, 3]. For the closely related edit distance the situation is similar, as the classic quadratic running time can be improved by logarithmic factors, but any truly subquadratic algorithm would falsify SETH [12].
These strong hardness results naturally bring up the question whether LCS or edit distance can be efficiently approximated (namely, whether an algorithm with truly subquadratic time for any constant , can produce a good approximation in the worst-case). In the last two decades, significant progress has been made towards designing efficient approximation algorithms for edit distance [14, 13, 15, 9, 7, 21, 23, 29, 17]; the latest achievement is a constant-factor approximation in almost-linear111By almost-linear we mean time for a constant that can be chosen arbitrarily small. time [8].
For LCS the picture is much more frustrating. The LCS problem has a simple -approximation algorithm with running time for any constant , and it has a trivial -approximation algorithm with running time for strings over alphabet . Yet, improving upon these naive bounds has evaded the community until very recently, making LCS a notoriously hard problem to approximate. In 2019, Rubinstein et al. [33] presented a subquadratic-time -approximation, where is the ratio of the string length to the length of the optimal LCS. For binary alphabet, Rubinstein and Song [34] recently improved the -approximation. In the general case (where and the alphabet size are arbitrary), the naive -approximation in near-linear222By near-linear we mean time , where hides polylogarithmic factors in . time was recently beaten by Hajiaghayi et al. [24], who designed a linear-time algorithm that computes an -approximation in expectation.333While the SODA proceedings version of [24] claimed a high probability bound, the newer corrected Arxiv version [25] only claims that the algorithm outputs an -approximation in expectation. Personal communications with the authors confirm that the result indeed holds only in expectation, see also Remark 14. Nonetheless, the gap between the upper bound provided by Hajiaghayi et al. [24] and the recent results on hardness of approximation [1, 5] remains huge.
1.1 Our Contribution
We present a randomized -approximation for LCS running in linear time , where the approximation guarantee holds with high probability444We say that an event happens with high probability (w.h.p.) if it has probability at least , where the constant can be chosen in advance.. More generally, we obtain a tradeoff between approximation guarantee and running time: For any we achieve approximation ratio in time . Formally we prove the following:
Theorem 1.
There is a randomized algorithm that, given strings of length and a time budget , with high probability computes a multiplicative -approximation of the length of the LCS of and in time .
The improvement over the state of the art can be summarized as follows:
1. An improved approximation ratio for the linear time regime: from [24] to ;
2. The first algorithm which improves upon the naive bound with high probability;
3. A generalization to running time , breaking the naive approximation ratio in general.
2 Technical Overview
We combine classic exact algorithms for LCS with different subsampling strategies to develop several algorithms that work in different regimes of the problem. A combination of these algorithms then yields the full approximation algorithm.
Our Algorithm 1 covers the regime of short LCS, i.e., when the LCS has length at most for an appropriate constant depending on the running time budget. In this regime, we decrease the length of the string by subsampling. This naturally allows to run classic exact algorithms for LCS on the subsampled string (which now has significantly smaller size) and the original string , while not deteriorating the LCS between the two strings too much.
For the remaining parts of the algorithm, the strings and are split into substrings and of length where denotes the total running time budget. For any block we write for the length of the LCS of and . We call a set with and a block sequence. Since we can assume the LCS of and to be long, it follows that there exists a good “block-aligned LCS”, more precisely there exists a block sequence with large LCS sum .
Now, a natural approach is to compute estimates
for all blocks and to determine the maximum sum over all block sequences . Once we have estimates , the maximum can be computed by dynamic programming in time , which is for our choice of . In the following we describe three different strategies to compute estimates . The major difficulty is that on average per block we can only afford time to compute an estimate .
The first strategy focuses on matching pairs. A matching pair of strings is a pair of indices such that . We write for the number of matching pairs of the strings and . Our Algorithm 2 works well if some block sequence has a large total number of matching pairs . Here the key observation (Lemma 7) is that for each block there exists a symbol that occurs at least times in both and . If is large, matching this symbol provides a good approximation for . Unfortunately, since we can afford only running time per block, finding a frequent symbol is difficult. We develop as a new tool an algorithm that w.h.p. finds a frequent symbol in each block with an above-average number of matching pairs, see Lemma 8.
For our remaining two strategies we can assume the optimal LCS to be large and to be small (i.e., every block sequence has a small total number of matching pairs). In our Algorithm 3, we analyze the case where is large. Here we pick some diagonal and run our basic approximation algorithm on each block along the diagonal. Since there are diagonals, an above-average diagonal has a total LCS of . If is large then this provides a good estimation of the LCS. The main difficulty is how to find an above-average diagonal. A random diagonal has a good LCS sum in expectation, but not necessarily with good probability. Our solution is a non-uniform sampling, where we first test random blocks until we find a block with large LCS, and then choose the diagonal containing this seed block. This sampling yields an above-average diagonal with good probability.
Recall that there always exists a block sequence with large LCS sum (see Lemma 11). The idea of our Algorithm 4 is to focus on a uniformly random subset of all blocks, where each block is picked with probability . Then on each picked block we can spend more time (specifically time ) to compute an estimate . Moreover, we still find a -fraction of . We analyze this algorithm in terms of and (the choice of depends on these two parameters) and show that it works well in the complementary regimes of Algorithms 1-3.
Comparison with the Previous Approach of Hajiaghayi et al. [24]
The general approach of splitting and into blocks and performing dynamic programming over estimates was introduced by Hajiaghayi et al. [24]. Moreover, our Algorithm 1 has essentially the same guarantees as [24, Algorithm 1], but ours is a simple combination of generic parts that we reuse in our later algorithms, thus simplifying the overall algorithm.
Our Algorithm 2 follows the same idea as [24, Algorithm 3], in that we want to find a frequent symbol in and and match only this symbol to obtain an estimate . Hajiaghayi et al. find a frequent symbol by picking a random symbol in each block ; in expectation appears at least times in and . In order to obtain with high probability guarantees, we need to develop a new tool for finding frequent symbols not only in expectation but even with high probability, see Lemma 8 and Remark 14.
The remainder of the approach differs significantly; our Algorithms 3 and 4 are very different compared to [24, Algorithms 2 and 4]. In the following we discuss their ideas. In [24, Algorithm 2], they argue about the alphabet size, splitting the alphabet into frequent and infrequent letters. For infrequent letters the total number of matching pairs is small, so augmenting a classic exact algorithm by subsampling works well. Therefore, they can assume that every letter is frequent and thus the alphabet size is small. We avoid this line of reasoning. Finally, [24, Algorithm 4] is their most involved algorithm. Assuming that their other algorithms have failed to produce a sufficiently good approximation, they show that each part and can be turned into a semi-permutation by a little subsampling. Then by leveraging Dilworth’s theorem and Tuŕan’s theorem they show that most blocks have an LCS length of at least ; this can be seen as a triangle inequality for LCS and is their most novel contribution. This results in a highly non-trivial algorithm making clever use of combinatorial machinery.
We show that these ideas can be completely avoided, by instead relying on classic algorithms based on matching pairs augmented by subsampling. Specifically, we replace their combinatorial machinery by our Algorithms 3 and 4 described above (recall that Algorithm 3 considers a non-uniformly sampled random diagonal while Algorithm 4 subsamples the set of blocks to be able to spend more time per block). We stress that our solution completely avoids the concept of semi-permutation or any heavy combinatorial machinery as used in [24, Algorithm 4], while providing a significantly improved approximation guarantee.
Organization of the Paper.
Section 3 introduces notation and a classical algorithm by Hunt and Szymanski. In Section 4 we present our new tools, in particular for finding frequent symbols. Section 5 contains our main algorithm, split into four parts that are presented in Sections 5.1, 5.3, 5.4, and 5.5, and combined in Section 5.6. In the appendix, for completeness we sketch the algorithm by Hunt and Szymanski (Appendix A) and we present pseudocode for all our algorithms (Appendix B).
3 Preliminaries
For we write . By the notation and we hide factors of the form . We use “with high probability” (w.h.p.) to denote probabilities of the form , where the constant can be chosen in advance.
String Notation.
A string over alphabet is a finite sequence of letters in . We denote its length by and its -th letter by . We also denote by the substring consisting of letters . For any indices the string forms a subsequence of . For strings we denote by the length of the longest common subsequence of and . In this paper we study the problem of approximating for given strings of length . We focus on the length , however, our algorithms can be easily adapted to also reconstruct a subsequence attaining the output length. If are clear from the context, we may replace by . Throughout the paper we assume that the alphabet is (this is without loss of generality after a -time preprocessing).
Matching Pairs.
For a symbol , we denote the number of times that appears in by , and call this the frequency of in . For strings and , a matching pair is a pair with . We denote the number of matching pairs by . If are clear from the context, we may replace by . Observe that . Using this equation we can compute in time .
Hunt and Szymanski [27] solved the LCS problem in time . More precisely, their algorithm can be viewed as having a preprocessing phase that only reads and runs in time , and a query phase that reads and and takes time .
Theorem 2 (Hunt and Szymanski [27]).
We can preprocess a string in time . Given a string and a preprocessed string , we can compute their LCS in time .
For convenience, we provide a proof sketch of their theorem in Appendix A.
4 New Basic Tools
4.1 Basic Approximation Algorithm
Throughout this section we abbreviate and . We start with the basic approximation algorithm that is central to our approach; most of our later algorithms use this as a subroutine. This algorithm subsamples the string and then runs Hunt and Szymanski’s algorithm (Theorem 2).
Lemma 3 (Basic Approximation Algorithm).
Let . We can preprocess in time . Given , the preprocessed string , and , in expected time we can compute a value that w.h.p. satisfies .
Proof.
In the preprocessing phase, we run the preprocessing of Theorem 2 on .
Fix a constant . If , then in the query phase we simply run Theorem 2, solving LCS exactly in time .
Otherwise, denote by a random subsequence of , where each letter is removed independently with probability (i.e., kept with probability ) for . Note that by our assumption on . We can sample in expected time
, since the difference from one unremoved letter to the next is geometrically distributed, and geometric random variates can be sampled in expected time
, see, e.g., [18]. Note that this subsampling yields and .
In the query phase, we sample and then run the query phase of Theorem 2 on and . This runs in time , which is in expectation.
Finally, consider a fixed LCS of and , namely for some and . Each letter survives the subsampling to with probability . Therefore, we can bound
from below by a binomial random variable
(the correct terminology is that statistically dominates ). Since is a sum of independent -variables, multiplicative Chernoff applies and yields . If then and , and thus . Otherwise, if , then we can only bound . In both cases, we have with high probability. ∎
The above lemma behaves poorly if , due to the “” in the approximation guarantee. We next show that this can be avoided, at the cost of increasing the running time by an additive .
Lemma 4 (Generalised Basic Approximation Algorithm).
Given and , in expected time we can compute a value that w.h.p. satisfies .
Proof.
We run the basic approximation algorithm from Lemma 3, which computes a value . Additionally, we compute the number of matching pairs in time . If , then there exists a matching pair, which yields a common subsequence of length 1. Therefore, if we set .
In the proof of Lemma 3 we showed that if then w.h.p. we have . We now argue differently in the case . If , then and we are done. If , then there must exist at least one matching pair, so , so the second part of our algorithm yields . Hence, in all cases w.h.p. we have . ∎
We now turn towards the problem of deciding for given and whether . To this end, we repeatedly call the basic approximation algorithm with geometrically decreasing approximation ratio . Note that with decreasing approximation ratio we get a better approximation guarantee at the cost of higher running time. The idea is that if the LCS is much shorter than the threshold , then already approximation ratio allows us to detect that . This yields a running time bound depending on the gap .
Lemma 5 (Basic Decision Algorithm).
Let . We can preprocess in time . Given , the preprocessed , and a number , in expected time we can w.h.p. correctly decide whether . Our algorithm has no false positives (and w.h.p. no false negatives).
Proof.
In the preprocessing phase, we run the preprocessing of Lemma 3. In the query phase, we repeatedly call the query phase of Lemma 3, with geometrically decreasing values of :
1. Preprocessing: Run the preprocessing of Lemma 3.
2. For :
1. Run the query phase of Lemma 3 with parameter to obtain an estimate .
2. If : return “
3. If : return “
Let us first argue correctness. Since Lemma 3 computes a common subsequence of , we have . Thus, if , we correctly infer . Moreover, w.h.p. satisfies . Therefore, if , we can infer , and this decision is correct with high probability. Finally, in the last iteration (where ), we have , and thus one of or must hold, so the algorithm indeed returns a decision.
The expected time of the query phase of Lemma 3 is . Since decreases geometrically, the total expected time of our algorithm is dominated by the last call.
If , the last call is at the latest for . This yields running time .
If , note that for any we have , and thus we return “”. Because we decrease by a factor 2 in each iteration, the last call satisfies . Hence, the expected running time is . If then this time bound simplifies to . If , then also , and the time bound becomes . In both cases we can bound the expected running time by the claimed , since . ∎
4.2 Approximating the Number of Matching Pairs
Recall that for given strings of length the number of matching pairs can be computed in time , which is linear in the input size. However, later in the paper we will split into substrings and into substrings , each of length , and we will need estimates of the numbers of matching pairs . In this setting, the input size is still (the total length of all strings and ) and the output size is (all numbers ), but we are not aware of any algorithm computing the numbers in near-linear time in the input plus output size .555In fact, one can show conditional lower bounds from Boolean matrix multiplication that rule out near-linear time for computing all ’s unless the exponent of matrix multiplication is . Therefore, we devise an approximation algorithm for estimating the number of matching pairs.
Lemma 6.
For write and . Given the strings and a number , we can compute values that w.h.p. satisfy , in total expected time .
This yields a near-linear-time constant-factor approximation of all above-average : By setting , in expected time we obtain a constant-factor approximation of all values with .
Proof.
The algorithm works as follows.
1. Graph Construction: Build a three-layered graph on vertex set , where has a node for every string , has a node for every string , and has a node for any and . Put an edge from to iff . Similarly, put an edge from to iff . Note that all frequencies and thus all edges of this graphs can be computed in total time . For and , we denote by their common neighbors. Note that any represents all matching pairs of symbol in and , and the number of these matching pairs is .
2. Subsampling: We sample a subset by removing each node independently with probability , where .
3. Determine Common Neighbors: For each enumerate all pairs of neighbors and . For each such 2-path, add to an initially empty set . This step computes the sets in time proportional to their total size.
4. Output: Return the values .
Correctness:
To analyze this algorithm, we consider the numbers . Observe that we have , since each corresponds to at least and at most matching pairs of and . It therefore suffices to show that is close to . Using Bernoulli random variables to express whether survives the subsampling, we write
˜Mij=∑(σ,ℓ,r)∈Uij2ℓ+rpℓ,r⋅Ber(pℓ,r).
This yields an expected value of , so by Markov’s inequality we obtain with probability at least . Since
is a linear combination of independent Bernoulli random variables, we can also easily express its variance as
V[˜Mij]=∑(σ,ℓ,r)∈Uij(2ℓ+r/pℓ,r)2⋅pℓ,r(1−pℓ,r)=∑(σ,ℓ,r)∈Uij2ℓ+r⋅2ℓ+r(1pℓ,r−1).
We now use the definition of to bound
2ℓ+r(1pℓ,r−1)=2ℓ+r(max{1,q2ℓ+r+3}−1)=max{0,q/8−2ℓ+r}≤q/8.
This yields . We now use Chebychev’s inequality on and to obtain
Pr[˜Mij<¯¯¯¯¯¯Mij/2]≤q2¯¯¯¯¯¯Mij.
In case , we have and hence . Otherwise, in case , we can only use the trivial .
Hence, each inequality and individually holds with probability at leat . Finally, we boost the success probability by repeating the above algorithm times and returning for each the median of all computed values .
Running Time:
Steps 1 and 2 can be easily seen to run in time . Steps 3 and 4 run in time proportional to the total size of all sets , which we claim to be at most in expectation. Over repetitions, we obtain a total expected running time of . (We remark that here we consider a succinct output format, where only the non-zero numbers are listed; otherwise additional time of is required to output the numbers .)
It remains to prove the claimed bound of . Since , from the definition of we infer . Therefore,
E[∑i,j|˜Uij|]≤E[8q∑i,j˜Mij]=8q∑i,j¯¯¯¯¯¯Mij≤8q∑i,jMij=8Mq.\qed
4.3 Single Symbol Approximation Algorithm
For strings that have a large number of matchings pairs , some symbol must appear often in and in . This yields a common subsequence using (several repetitions of) a single alphabet symbol.
Lemma 7 (Cf. Lemma 6.6.(ii) in [20] or Algorithm 3 in [24]).
For any there exists a symbol that appears at least times in and in . Therefore, in time we can compute a common subsequence of of length at least . In particular, we can compute a value that satisfies .
Proof.
Let be maximal such that some symbol appears at least times in and at least times in . Let for . Since no symbol appears more than times in and in , we have . We can thus bound
M=M(x,y)=∑σ∈Σ#σ(x)⋅#σ(y)≤∑σ∈Σxk⋅#σ(y)+∑σ∈Σy#σ(x)⋅k≤2kn,
since the frequencies sum up to at most , and similarly for . It follows that . Computing , and a symbol attaining , in time is straightforward. ∎
We devise a variant of Lemma 7 in the following setting. For strings , we write , and . We want to find for each block a frequent symbol in and , or equivalently we want to find a common subsequence of and using a single alphabet symbol. Similarly to Lemma 6, we relax Lemma 7 to obtain a fast running time.
Lemma 8.
Given and any , we can compute for each a number such that w.h.p. . The algorithm runs in total expected time .
Proof.
We run the same algorithm as in Lemma 6, except that in Step 4 for each with non-empty set we let be the maximum of over all . For each empty set , we implicitly set , i.e., we output a sparse representation of all non-zero values .
The running time analysis is the same as in Lemma 6.
For the upper bound on , since appears at least times in and at least times in , there is a common subsequence of and of length at least . Thus, we have .
For the lower bound on , fix and order the tuples in ascending order of , obtaining an ordering . For we let and . Recall that , and observe that we can pick with
∑(σ,ℓ,r)∈S2ℓ+r≥¯¯¯¯¯¯Mij/2and∑(σ,ℓ,r)∈L2ℓ+r≥¯¯¯¯¯¯Mij/2. (1)
Then we have
¯¯¯¯¯¯Mij2≤∑(σ,ℓ,r)∈S2ℓ+r=∑(σ,ℓ,r)∈S2min{ℓ,r}⋅2max{ℓ,r}≤2min{ℓh,rh}∑(σ,ℓ,r)∈S2max{ℓ,r}.
Note that for any the symbol appears at least times in or in , and thus the sum on the right hand side is at most . Rearranging, this yields , where we used as in the proof of Lemma 6. In particular, due to our ordering we have for any :
2min{ℓ,r}≥2min{ℓh,rh}≥Mij16m. (2)
Consider the number of nodes in surviving the subsampling, i.e., . If , then some node in survived, and thus by (2) the computed value is at least . It thus remains to analyze .
In case some has , we have with probability 1. Otherwise all have and thus . In this case, we write as a sum of independent Bernoulli random variates in the form . In particular,
E[Z]=∑(σ,ℓ,r)∈L2ℓ+r+3/q(???)≥4¯¯¯¯¯¯Mijq≥Mijq.
Since is a sum of independent -variables, multiplicative Chernoff applies and yields . We thus obtain
Pr[Z>0]≥1−Pr[Z
In case , we obtain , and thus we have with probability at least . Otherwise, in case , we can only use the trivial bound . In any case, we have with probability at least . Similar to the proof of Lemma 6, we run independent repetitions of this algorithm and return for each the maximum of all computed values , to boost the success probability and finish the proof. ∎
5 Main Algorithm
In this section we prove Theorem 1. First we show that Theorem 9 implies Theorem 1, and then in the remainder of this section we prove Theorem 9.
Theorem 9 (Main Result, Relaxation).
Given strings of length and a time budget , in expected time we can compute a number such that and w.h.p. .
Recall Theorem 1:
See 1
Proof of Theorem 1 assuming Theorem 9.
Note that the difference between Theorems 1 and 9 is that the latter allows expected running time and has an additional slack of logarithmic factors in the running time.
In order to remove the expected running time, we abort the algorithm from Theorem 9 after time steps. By Markov’s inequality, we can choose the hidden constants and logfactors such that the probability of aborting is at most . We boost the success probability of this adapted algorithm by running independent repetitions and returning the maximum over all computed values . This yields an -approximation with high probability in time .
To remove the logfactors in the running time, as the first step in our algorithm we subsample the given strings , keeping each symbol independently with probability , resulting in subsampled strings . Since any common subsequence of is also a common subsequence of , the estimate that we compute for satisfies . Moreover, if then by Chernoff bound with high probability we have , so that an -approximation on also yields an -approximation on . Otherwise, if , then in order to compute a -approximation it suffices to compute an LCS of length 1, which is just a matching pair and can be found in time (assuming that the alphabet is ).
This yields an algorithm that computes a value such that w.h.p. . The algorithm runs in time , and this running time bound holds deterministically, i.e., with probability 1. Hence, we proved Theorem 1. ∎
It remains to prove Theorem 9. Our algorithm is a combination of four methods that work well in different regimes of the problem, see Sections 5.1, 5.3, 5.4, and 5.5. We will combine these methods in Section 5.6.
5.1 Algorithm 1: Small L
Algorithm 1 works well if the LCS is short. It yields the following result.
Theorem 10 (Algorithm 1).
We can compute in expected time an estimate that w.h.p. satisfies .
Proof.
Our Algorithm 1 works as follows.
1. Run Lemma 7 on and .
2. Run Lemma 4 on and with .
3. Output the larger of the two common subsequence lengths computed in Steps 1 and 2.
Running Time:
Step 1 runs in time . Step 2 runs in expected time . Since we have , so the expected running time is .
Upper Bound:
Steps 1 and 2 compute common subsequences, so the computed estimate satisfies .
Approximation Guarantee:
Note that Step 1 guarantees and Step 2 guarantees w.h.p. . If then and , so we solved the problem exactly. Otherwise we have and | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9706261157989502, "perplexity": 577.9814571756353}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320301592.29/warc/CC-MAIN-20220119215632-20220120005632-00093.warc.gz"} |
https://codereview.stackexchange.com/questions/197019/scaling-decimal-numbers-up-within-bounds-of-limit/197070 | # Scaling decimal numbers up within bounds of limit
This code is part of a simulation and inputs will be positive values less than one and inputs are constrained elsewhere. The goal of the algorithm is to scale the inputs up to much larger numbers, although the total sum is bounded. These represent the number of entities in the simulation.
Conceptually it is best to remember that the value 0.001 can also be expressed as 10^-3 and 4.2*10^-3 is also written as 0.0042. What the algorithm is trying to do is determine the exponent needed such that all of the numbers are positive integer values. Once all of the inputs are integers is then ensures that they are scaled within the bound of the maximum entities.
For example, if the simulation has a limit of MAX_ENTITY_COUNT = 1000000 entities and the user enters input[0].raw = 0.01, and input[1] = 0.1 I would expect to see input[0].count = 90900 and input[1].count = 909000 for a total of 999,900 entities.
private void findEntityCount(List<Inputs> input) {
// Find the smallest exponent based upon the natural log
int smallest = Integer.MAX_VALUE;
for (Inputs entry : input) {
int exp = (int)Math.log(entry.raw);
if (exp < smallest) {
smallest = exp;
}
}
// Calculate the scaling, note that this is closely related to finding the
// mantissa of the input value, but subtracting one from the value helps
// pack things a bit better
long total = 0;
double scaling = Math.pow(10, Math.abs(smallest) - 1);
for (Inputs entry : input) {
entry.count = (long)Math.ceil(entry.raw * scaling);
total += entry.count;
}
// Use the initial total to find a multiplier that we can use to adjust
// the initial counts to the final count for the simulation
double multiplier = MAX_ENTITY_COUNT / total;
for (Inputs entry : input) {
entry.count *= multiplier;
}
}
So far this code appears to be working well and resulting in quantities that are scaled correctly and pack the space fairly well. However, since it is playing around with how floating points are stored I'm looking for feedback that:
1. The approach makes sense (i.e., there isn't a better way to do it that is clearer).
2. What are some pitfalls that I should be aware of.
I haven't seen any issues yet, but generally I've also only seen a limited range of inputs.
• Wouldn't 90909/909090 be a better solution for the input 0.1/0.01? And what would be the expected output for 0.1/0.1234567 ? Making the second number an integer gives 1234567, and that is already larger than MAX_ENTITY_COUNT. – Martin R Jun 24 '18 at 14:56
• @MartinR In the first case, yes that would be a better fit, but I can't think of an algorithm that works well for arbitrary numbers. In that sense it's actually kind of an interesting problem. I'm not sure I understand the second part of your comment. – anonymous Jun 25 '18 at 4:05
• I am just asking what the expected output would be for input[0].raw = 0.1, input[1] = 0.1234567 and MAX_ENTITY_COUNT = 1000000 (and why). Or, as a simpler example input[0].raw = 0.1, input[1] = 0.1234 and MAX_ENTITY_COUNT = 100. – Martin R Jun 25 '18 at 5:51
• @MartinR The way the code is setup right now it bounds that to a 1:2 ratio, which is obviously wrong. However, given the user input that case has never actually come up and I'm not sure it will. Most of the input's I've seen before have been "human friendly" ratios that you can figure out in you head. – anonymous Jun 25 '18 at 7:24
• However, looking at that input again, the 1:2 ratio is "close enough" that it might be acceptable in practice. The minimum entity count is 1E5 so that also helps things out as well. Let me think on things for a bit and reply back. I suspect for the purposes of the problem having a 1:2 ratio come back for those figures would be considered "correctly packed." – anonymous Jun 25 '18 at 7:26
double smallest = Double.MAX_VALUE;
This is even larger:
double smallest = Double.POSITIVE_INFINITY;
if (exp < smallest) {
smallest = exp;
}
Unless you need to do something else in the body, like remembering an index, this can better be replaced with:
smallest = Math.min(smallest, exp);
Anti-pattern: The -1 you describe is a 'magic value', which in this case, after a bit of reverse engineering, just divides scaling by 10, like so:
double scaling = Math.pow(10, Math.abs(smallest)) / 10;
This is clearer to casual readers of your code, but still a magic number unless rationalized in the comments.
Pitfall: There is no check if entry.raw is actually not larger than one. If it is, your approach breaks.
Performance / Precision / Confusing: don't calculate base-e log for every number and then base-10 exp (that combination alone is already confusing enough). Just find the very smallest number (not the smallest exponent) and set double scaling = 1.0 / smallest;. To get a number-correct result to your current implementation, because of the base confusion, it would be:
double scaling = 40.287487705590465 / smallest;
Note that this just moves the 'magic number' problem. You need to rationally explain the value here, and not just state that it 'packs things better'. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7416363954544067, "perplexity": 1255.388103604833}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496664567.4/warc/CC-MAIN-20191112024224-20191112052224-00491.warc.gz"} |
https://www.physicsforums.com/threads/faradays-cage.440674/ | 1. Oct 22, 2010
### alphaomega@ho
hello,
I have a very simple question: a hollow sphere has the propertie that in the sphere the electric field, due to being charged , is zero
is it in the whole sphere?
for example, near the inside surface of the sphere, the the electric field of the nearest charge will be geater than the elctric field of the charge wich is a the other side...
what about non regular hollow object , is the electric field also zero than (because of its geometry)
thank you very much!
2. Oct 22, 2010
### zhermes
If its a net-uncharged, conducting sphere then yes.
If you are so close to the surface of the sphere that the charge density is no longer uniform, but instead you can "see" individual charges, then no--the field won't be identically zero, but still very close.
Still zero.
3. Oct 23, 2010
### alphaomega@ho
what do you mean with net-uncharged ?
I find it difficult to understand why in a non regular onbject the field whtin is zero
I've seen the disctraction for the a hollow sphere, with those space angle whom causes opposite field vector in this field (reason why the field is zero) => but in a non regular hollow object this isn't true, so whats the reason of havving no netto electric field insie that object?
for example a car...
thank you very mucg
4. Oct 23, 2010
### zhermes
The argument makes no assumption about the particular shape/features of the hollow object except that it is closed, conducting, and uncharged. Think about the inner surface of the conducting object. If there was still a residual electric field there, then electrons on the surface would feel a force and therefore move. Thus the system would not be in equilibrium. The only possible equilibrium configuration, and the lowest energy configuration (thus the preferred configuration), is if there is no electric field at the inner surface.
5. Oct 23, 2010
### alphaomega@ho
so the conclusion:
a hollow object (no matter what shape) with a equally divided charged surface(dq/dA is overall the same) has a electric field inside that has a netto value = 0
thank you very much
6. Oct 23, 2010
### zhermes
Yes, except that $$\frac{dq}{dA}$$ isn't necessarily constant over the surface. I think it will only be constant in the case of zero divergence in the external field, across the surface. Can anyone reading this confirm or deny?
7. Oct 23, 2010
### alphaomega@ho
I mean that dq/dA must be equal over the outer surface
suppose all the charge q is spread out over 1/100 of the outer surface somewhere, in the inside of the object will be an netto electric field
there's no other charge wich creates a internal field opposits to the other dE creates by the other charge on the surface, I think...
what did you mean with zero divergence in the external field ?
8. Oct 26, 2010
### alphaomega@ho
is my statement that I made above correct ?
thank you !
9. Oct 26, 2010
### zhermes
Consider a point-charge located outside the hollow conductor (of arbitrary shape). The induced charge density on the sphere surface will be non-homogeneous, even though the electric field inside the cavity would be zero.
10. Oct 27, 2010
### alphaomega@ho
something like the picture for example?
that I do understand, but for a non homogeneous dq/dA over the outer surface I find it very strange
but I'll except it...
thank you | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9222405552864075, "perplexity": 1198.131317127091}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501170884.63/warc/CC-MAIN-20170219104610-00406-ip-10-171-10-108.ec2.internal.warc.gz"} |
https://www.mathxplain.com/calculus-3/matrices-and-vectors/the-equation-of-the-line-and-the-equation-of-the-plane | Contents of this Calculus 3 episode:
The equatin of the line, The equatin of the plane, Normal vector, Vector between 2 points, Distance of 2 points, Direction vector, System of equation of the line.
Text of slideshow
It's time to do some geometry.
There's nothing to worry about, it's just a few little things. Let's start with vectors and lines in the plain.
The equation of a line and the equation of a plane
It's time to do some geometry.
There's nothing to worry about, it's just a few little things. Let's start with vectors and lines in the plane.
EQUATION OF A LINE: If is a point on the line, and
is the normal vector of the line:
Just a reminder: the normal vector of a line is
the non-zero vector that is perpendicular to that line.
VECTOR BETWEEN 2 POINTS: If and are points,
then the vector between these points:
DISTANCE OF 2 POINTS: If and are points,
then the distance between these points:
It's all the same in space, except there are three coordinates.
EQUATION OF A PLANE: If is on the plane and
is the normal vector of the plane:
Just a reminder: the normal vector of a line is
the non-zero vector that is perpendicular to that line.
VECTOR BETWEEN 2 POINTS: If and are points,
then the vector between these points:
DISTANCE OF 2 POINTS: If and are points,
then the distance between these points:
Let's try to come up with the equation of a line in space. This would be useful for us, but it is not included in this list.
Unfortunately there will be some problems with it, but let's try anyway.
Let's find the equation of the line where point is on the line, and
is the direction vector of the line.
Here, we have to use the direction vector instead of the normal vector, because in space
it is not obvious which vector is perpendicular to the line.
The direction vector, on the other hand, is specific, only its length may vary.
If is an arbitrary point on the line, then
This vector is a multiple of the line's direction vector
If , then we divide by it, if it is zero, then
If , then we divide by it, if it is zero, then
If , then we divide by it, if it is zero, then
All of them are equal to , therefore they must be equal to each other, too.
This is the system of equations of a line in space.
Let's see an example:
Find the equation of the line where point is on the line, and
is the direction vector of the line.
Here is the system of equations of the line:
Unfortunately, will cause some trouble.
In such cases
Next, let's see a typical exercise.
Find the equation of a line in the plane, where point is on the line, and the line is perpendicular to the line described by the equation of
Find the equation of a plane in space, where point is on the plane and the plane is perpendicular to the line described by the following system of equations:
The normal vector of line is
We can make use of this vector if
we rotate it by , because then
it will be the normal vector of the line we are trying to define.
To rotate a vector in the plane by ,
we swap its coordinates,
and multiply one of them by .
We have the normal vector, so
the equation of the line is:
Let's see what we can do over here.
The normal vector of the plane happens to be the direction vector of the line.
The direction vector of the line:
The normal vector of the plane:
Here comes the equation of the plane:
And finally, another typical exercise.
Find the equation of a line in the plane, where points and are on the line.
Find the equation of the plane in space, where points , , and are on the plane.
If is a point on the plane and
is the normal vector of the plane, the equation of the line will be:
If is a point on the plane and
is the normal vector of the plane, the equation of the plane will be:
We have plenty of points, but we don't have a single normal vector,
so we have to make one.
Let's rotate this by , and that gives us the normal vector.
To rotate a vector in the plane by ,
we swap its coordinates,
and multiply one of them by .
The equation of the line:
We will have a problem with the plane here.
In space there is no such thing
as rotating a vector by .
We have to figure out something else to get the plane's normal vector.
We would need a vector that is perpendicular to the triangle determined by points , , and . This vector will be the so called cross product.
# The equation of the line and the equation of the plane
06
Let's see this
Calculus 3 episode | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9007354974746704, "perplexity": 319.6013673324001}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107874026.22/warc/CC-MAIN-20201020162922-20201020192922-00161.warc.gz"} |
http://www.math.ubc.ca/~andrewr/CLP/clp_1_dc/sec_invTrig.html | We are now going to consider the problem of finding the derivatives of the inverses of trigonometric functions. Now is a very good time to go back and reread Section 0.6 on inverse functions — especially Definition 0.6.4. Most importantly, given a function $f(x)\text{,}$ its inverse function $f^{-1}(x)$ only exists, with domain $D\text{,}$ when $f(x)$ passes the “horizontal line test”, which says that for each $Y$ in $D$ the horizontal line $y=Y$ intersects the graph $y=f(x)$ exactly once. (That is, $f(x)$ is a one-to-one function.)
Let us start by playing with the sine function and determine how to restrict the domain of $\sin x$ so that its inverse function exists. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8621153235435486, "perplexity": 108.0749823761531}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806509.31/warc/CC-MAIN-20171122065449-20171122085449-00207.warc.gz"} |
https://codeforces.com/problemset/problem/720/C | C. Homework
time limit per test
3 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Today Peter has got an additional homework for tomorrow. The teacher has given three integers to him: n, m and k, and asked him to mark one or more squares on a square grid of size n × m.
The marked squares must form a connected figure, and there must be exactly k triples of marked squares that form an L-shaped tromino — all three squares are inside a 2 × 2 square.
The set of squares forms a connected figure if it is possible to get from any square to any other one if you are allowed to move from a square to any adjacent by a common side square.
Peter cannot fulfill the task, so he asks you for help. Help him to create such figure.
Input
Input data contains one or more test cases. The first line contains the number of test cases t (1 ≤ t ≤ 100).
Each of the following t test cases is described by a line that contains three integers: n, m and k (3 ≤ n, m, n × m ≤ 105, 0 ≤ k ≤ 109).
The sum of values of n × m for all tests in one input data doesn't exceed 105.
Output
For each test case print the answer.
If it is possible to create such figure, print n lines, m characters each, use asterisk '*' to denote the marked square, and dot '.' to denote the unmarked one.
If there is no solution, print -1.
Print empty line between test cases.
Example
Input
33 3 43 3 53 3 3
Output
.*.***.*.**.**.*...*.****.. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2802371680736542, "perplexity": 695.8053216955929}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662510097.3/warc/CC-MAIN-20220516073101-20220516103101-00004.warc.gz"} |
https://tex.stackexchange.com/questions/253295/difference-between-framebox-and-boxed/253297#253297 | # Difference between \framebox{} and \boxed{}
I want to put an equation in a frame box. Is it the same that if I create a framed text box environment first then put the equation inside or use the environment \boxed{}?
\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\begin{document}
\framebox{$a^2+b^2=c^2$}
$\boxed{a^2+b^2=c^2}$
\end{document}
Package amsmath defines \boxed:
\newcommand{\boxed}[1]{\fbox{\m@th$\displaystyle#1$}}
\framebox and \fbox are just different interfaces for the same internal \@frameb@x, which actually makes the box. \framebox has more options.
Thus, the main difference between \framebox{$...$} and $\boxed{...}$ is that \boxed sets \displaystyle, whereas it had to be done manually in the former variant: \framebox{$\displaystyle ...$}.
Another difference appears, if \mathsurround is not zero. This space is set, when TeX enters and leaves inline math mode. It is intended as separation of math from the surrounding text. Inside the box it does not make sense and \boxed removes it by setting \mathsurround to zero by \m@th.
A test file, which illustrates the differences:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{amsmath}
\begin{document}
\newcommand*{\vs}{\mathrel{\text{vs.}}}
\begin{align*}
\text{\ttfamily\string\framebox\{\$\dots\$\}} &\vs
\text{\ttfamily\string\boxed\{\dots\}}
\\
\framebox{$\frac{123}{456}$} &\vs \boxed{\frac{123}{456}}
\\
\setlength{\mathsurround}{1em}\framebox{$X$} &\vs
\setlength{\mathsurround}{1em}\boxed{X}
\end{align*}
\end{document}
A simulation of \boxed would be:
\framebox{%
\setlength{\mathsurround}{0pt}%
$\displaystyle ...$%
}
• Thanks for the helpful reply! By the way, would you please tell me where I can find the definition of \boxed? Jul 2 '15 at 10:43
• @ZhangZe kpsewhich amsmath.sty (or locate the package file amsmath.sty by means of the OS), then line 307 (in version 2013/01/14 v2.14). Jul 2 '15 at 11:06
• Okay. Gotta it! Jul 2 '15 at 11:17
For such questions I just load the package lua-visual-debug. You can see clearly that they are both the same:
% arara: lualatex
\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{blindtext}
\usepackage{lua-visual-debug}
\parindent0pt
\begin{document}
\blindtext
\framebox{$\displaystyle a^2+b^2=c^2$} % displaystyle needed here, as it is set in \boxed by default. It just changes the horizontal spacing of the powers a bit.
$\boxed{a^2+b^2=c^2}$
\blindtext
\end{document}
The boxing is equal speaking of spacing and aligning. Therefore, both approaches are similar. For the syntactical equivalence, see Heiko's answer. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9729504585266113, "perplexity": 3421.111016614425}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358078.2/warc/CC-MAIN-20211127013935-20211127043935-00135.warc.gz"} |
https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-010-1237-2 | The European Physical Journal C
, Volume 66, Issue 1–2, pp 271–281
# Probing scalar particle and unparticle couplings in $$e^{+}e^{-}\to t\bar{t}$$ with transversely polarized beams
Regular Article - Theoretical Physics
## Abstract
In searching for indications of new-physics scalar particle and unparticle couplings in $$e^{+}e^{-}\to t\bar{t}$$ , we consider the role of transversely polarized initial beams at e+e colliders. By using a general relativistic spin density matrix formalism for describing the particles spin states, we find analytical expressions for the differential cross section of the process with t or $$\bar{t}$$ polarization measured, including the anomalous coupling contributions. Thanks to the transversely polarized initial beams these contributions are first order anomalous coupling corrections to the Standard Model (SM) contributions. We present and analyze the main features of the SM and anomalous coupling contributions. We show how differences between SM and anomalous coupling contributions provide means to search for anomalous coupling manifestations at future e+e linear colliders. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8842342495918274, "perplexity": 1830.208350467347}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549424247.30/warc/CC-MAIN-20170723042657-20170723062657-00522.warc.gz"} |
http://eprints.adm.unipi.it/1980/ | # Fast fraction-free triangularization of Bezoutians with applications to sub-resultant chain computation
Bini, D. A. and Gemignani, Luca (1997) Fast fraction-free triangularization of Bezoutians with applications to sub-resultant chain computation. Technical Report del Dipartimento di Informatica . Università di Pisa, Pisa, IT.
An algorithm for the computation of the LU factorization over the integers of an $n\times n$ Bezoutian $B$ is presented. The algorithm requires $O(n^2)$ arithmetic operations and involves integers having at most $O(n\log nc)$ bits, where $c$ is an upper bound of the moduli of the integer entries of $B$. As an application, by using the correlations between Bezoutians and the Euclidean scheme, we devise a new division-free algorithm for the computation of the polynomial pseudo-remainder sequence of two polynomials of degree at most $n$ in $O(n^2)$ arithmetic operations. The growth of the length of the integers involved in the computation is kept at the minimum value, i.e., $O(n\log nc)$ bits, no matter if the sequence is normal or not, where $c$ is an upper bound of the moduli of the input coefficients. The algorithms, that rely on the Bareiss technique and on the properties of the Schur complements of Bezoutians , improve the previous ones. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9493411779403687, "perplexity": 447.2503042050648}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794869732.36/warc/CC-MAIN-20180527170428-20180527190428-00200.warc.gz"} |
https://ctftime.org/task/138 | Points: 400
Tags: bin
Poll rating:
You are trapped at a military base, you got zombies coming from the right, left and front. Of course, you are running out of ammo and there is no much hope left, but there is a huge door behind you. You got reason to believe that there is a tank behind it, but it is secured with a secret masterkey. There is also a terminal on the left side with a binary on it to authenticate and open the door called "tank". You are lucky and the developer was really exhausted when creating the application, so there might be some bugs you can use to get the masterkey, but watch out for the zombies!
SSH: ctf.fluxfingers.net
PORT: 2095
USER: ctf
PASS: xxx
Writeups
ActionRatingAuthor team
0
Delusions of Grandeur
You need to authenticate and join a team to post writeups webpentest – Oct. 25, 2012, 9:02 p.m.
The writeup is cool, but unnecessary complex. You can make tank read the masterkey itself by making sessionfile a symlink - it the outputs its contents to logfile =)
The following bash did the trick for us:
for i in {1..1000} ; do
rm -f .sessionid
(sleep 0.1 ; ~/tank sadhfkjshdfkjh) &
pid=$! while true ; do if [ -f .sessionid ] ; then ln -sf /home/ctf/masterkey .sessionid break fi done wait$pid
done
After that the logfile contained the flag as one of the session ids.
cutz – Oct. 26, 2012, 7:19 a.m.
Well I know that the symlink solution was not intended by the author, and also the Buffer Overflow should have actually been quite tricky, but the binary unintentionally did not inforce w^x pages, so the stack was executable ...
webpentest – Oct. 26, 2012, 1:19 p.m.
Why then bother writing anything to the logfile? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.42889589071273804, "perplexity": 2835.9694864884837}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987836295.98/warc/CC-MAIN-20191023201520-20191023225020-00467.warc.gz"} |
https://answerbun.com/physics/numerical-modeling-of-induced-voltage/ | # Numerical modeling of induced voltage
I have an arbitrary magnetic field that varies with time, and I’m trying to numerically model the induced current in a resistive loop over time. Details below.
I’m building an electromagnetic accelerator for fun & learning: it’s a coil that I’ll fire high current through, to induce an eddy current on a projectile. It’s basically a 500:1 transformer, except I’m not sure how strong the coupling is.
I’m numerically modeling it in Python before I build it. I’m trying to minimize chalkboard-style assumptions; e.g. I’m using the Biot-Savart law to integrate the magnetic field from each differential element of the coil.
My problem is: I’m not sure how to figure out eddy current in the projectile at a given timestep. I can get the induced voltage given a change in magnetic flux, but I’m not quite sure how to handle the feedback effect from the induced eddy current. I.e. how do I handle the fact that the rising eddy current reduces the rate of rise of magnetic flux that produced the eddy current? It feels like I need to solve an equation at each timestep to get the "equilibrium" eddy current, but it’s been a while since my EE classes.
And again, I’m not looking to model it with simple equations for transformers; I actually want to further break down the projectile into "finite element" loops and find the induced current in each. (Because it looks like distribution of eddy current in the projectile will be important, as will its resistivity.)
Physics Asked by Luke on December 31, 2020
OK, I figured it out: Apply Faraday's induced voltage law on each of the 2 coils, using the magnetic flux due to each of the 2 coils, yielding 2*2=4 total contributions. And then solve the system of equations so the currents are consistent with the induced voltages.
I used my favorite optimizer/constraint solver, cvxpy to do it. Here's the Python code:
def solveForCurrents(i1_init, i2_init, flux1dueto1, flux2dueto1, flux2dueto2, flux1dueto2, r1,r2,external_emf_1,external_emf_2, dt):
""" Convention:
flux2dueto1 is (coil2 number of turns) * (the surface integral of magnetic flux through coil 2, per amp through coil 1).
external_emf_1 is a voltage in series with coil 1, e.g. the instantaneous voltage on a capacitor.
r1 is the total resistance of coil 1, including equivalent series resistance (ESR) of capacitors etc.
"""
import cvxpy
flux1_init = flux1dueto1*i1_init + flux1dueto2*i2_init
flux2_init = flux2dueto1 * i1_init + flux2dueto2 * i2_init
i1 = cvxpy.Variable(1) #variables to be solved for in the system of equations
i2 = cvxpy.Variable(1)
flux1 = flux1dueto1 * i1 + flux1dueto2 * i2 #total flux through a coil is the sum of all sources. (The flux1dueto1 captures the effect of self-inductance)
flux2 = flux2dueto1 * i1 + flux2dueto2 * i2
induced_emf1 = -1 * (flux1 - flux1_init) / dt #Faraday's law: induced voltage = -1 * change in flux per time.
induced_emf2 = -1 * (flux2 - flux2_init) / dt
constraints = [(induced_emf1 + external_emf_1) == i1 * r1, #Ohm's law: V=IR
(induced_emf2 + external_emf_2) == i2 * r2]
prob = cvxpy.Problem(cvxpy.Minimize(1), constraints=constraints) #nothing to minimize; just solving for the constraints
prob.solve()
return i1.value[0], i2.value[0]
#example usage. Would run this in a loop supplying i1 and i2 as the next timestep's i1_init and i2_init
i1, i2 = solveForCurrents(i1_init=0, i2_init=0, flux1dueto1=0.1, flux2dueto1=0.01, flux2dueto2=0.01, flux1dueto2=0.001, r1=1,r2=10,external_emf_1=1000,external_emf_2=0, dt=0.001)
In my case, to get the flux2dueto1 for a given coil geometry, I used the Biot-Savart law with a 1 amp current through coil 1, to find the magnetic field at a point on the face of coil 2. I repeated for a 20x20 grid across the face of coil 2, numerically integrating the results to get the integral of flux through the coil. (That surface-integral code isn't shown above; my implementation was pretty specific to my geometry.)
I can cache and reuse that same value of "flux per amp" to get the flux due to any value of current (as long as the geometry stays the same. If geometry changes then flux2dueto1 needs to be recalculated).
Answered by Luke on December 31, 2020
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https://www.physicsforums.com/threads/nodal-analysis-problem.610949/ | # Homework Help: Nodal Analysis Problem
1. Jun 2, 2012
### Lancelot59
I need to find V0 in the given circuit. I've uploaded both the problem, and an annotated one with the variables I chose.
These are the equations I got for the system:
$$V_{0}=30-V_{2}-V_{3}$$
$$V_{2}=30-i_{1}(10\Omega )$$
$$V_{2}=I_{X}(2\Omega )$$
$$V_{3}=30-V_{2}-(-i_{1})(1\Omega )$$
$$V_{0}=i_{4}(5\Omega )$$
$$I_{X}=i_{1}+i_{2}$$
$$4I_{X}=i_{2}+i_{4}$$
Does this look right? I'm fairly certain I'm doing this wrong, as I got -15/7A for the current i1.
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18.9 KB
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2. Jun 2, 2012
### Staff: Mentor
You V2 and V3 represent node potentials, not potential differences across the 10 and 1 Ohms resistances. So your first equation is not correct; The same problem exists in several of your other equations, and you've introduced current variables I1 and I2 which are not necessary for writing the node equations.
Clearly V3 and Vo must be the the potentials at the same node (they are connected by a wire), so V3 is in fact equal to Vo and there's no need to have duplicate variables.
How many independent nodes do you count for your circuit? You only need that many node equations, plus one equation for each controlled power supply.
3. Jun 3, 2012
### Lancelot59
Okay. Well then I can count 2 nodes. One after the 10Ohm resistor, and one after the 1Ohm resistor. I also want to count the ground rail.
4. Jun 3, 2012
### Staff: Mentor
Okay, so then you should write two equations for the two independent nodes that you've identified (the ground rail is the reference node and doesn't require a separate equation) and one equation that gives the controlled current source value in terms of node potentials.
5. Jun 3, 2012
### Lancelot59
Thus far I have:
Node1
$$I_{x}=i_{1}+i_{2}$$
$$\frac{V_{1}}{2}=\frac{30-V_{1}}{10}+\frac{V_{2}-V_{1}}{1}$$
Node 2
$$4I_{x}=i_{2}+i_{3}$$
$$4I_{x}=\frac{V_{2}-V_{1}}{1}+\frac{V_{0}}{5}$$
I should be able to eliminate a variable since V0 will be equal to V2.
6. Jun 3, 2012
### Staff: Mentor
Yes. You also don't need variables i1 or i2, since Ix can be easily obtained from the node voltage V1. That's the "other" equation I was referring to with regards to the controlled source.
7. Jun 3, 2012
### Lancelot59
Idea! I pulled a third equation:
$$30=V_{1}+V_{2}$$
and therefore:
$$30=V_{1}+V_{0}$$
I got some numbers by using this form.
V0=222/5
V1=237/8
I posted this just as you replied. I'll review what you said and take a look at it.
8. Jun 3, 2012
### Staff: Mentor
This is not true! V1 and V2 are NODE POTENTIALS, not resistor voltage drops.
You should be able to find Ix from a node potential though... (in fact, it's included as a term in your Node1 equation )
Last edited: Jun 3, 2012
9. Jun 3, 2012
### Lancelot59
Why not though? At V2 the only two branches are the resistor and the current source. Therefore V2 is the only potential left to drop before it hits the ground rail.
I do have Ix there, but there are only two equations. I have three variables...
10. Jun 3, 2012
### Staff: Mentor
Node 2 has three connections: the path to node 1, the path to the controlled current source, and the path to the load resistor.
NOTE: Node voltages ARE NOT RESISTOR DROPS. They are the potentials, w.r.t. ground, of those nodes. If a resistor happens to be connected between a given node and ground, then it will THEN also be that resistor's potential drop. But you should know this already by HOW you write the node equations, right? You take the DIFFERENCE between node potentials for the resistance that lies between the two nodes.
Yes, so you want to write an equation for Ix. Hint: You've already incorporated an expression for Ix in your equation for node 1.
11. Jun 3, 2012
### Lancelot59
I see what you mean there. I was looking at it the wrong way. I think this is the equation you're referring to:
$$V_{1}=I_{x}*2\Omega$$
Since the drop across that will be equivalent to V1.
Doing that substitution I found V0 to be 15/19
Last edited: Jun 3, 2012
12. Jun 3, 2012
### Staff: Mentor
Your expression for Ix looks fine, but I think your reduction for Vo from the node equations does not look correct. Can you detail your work?
13. Jun 3, 2012
### Lancelot59
On review I botched something along the way. Revised work:
Rearranged node 1:
$$\frac{8}{5}V_{1}=3+V_{2}$$
$$V_{1}=\frac{5}{8}(3+V_{2})$$
$$V_{1}=\frac{15}{8}+V_{2}$$
Node 2 rearranged to:
$$3V_{1}=\frac{6}{5}V_{0}$$
after first using this equation:
$$3V_{1}=2I_{x}$$
to sub out the Ix term from it.
Combining them together, and replacing any instances of V2 with V0:
$$3(\frac{15}{8}+V_{0})=\frac{6}{5}V_{0}$$
I then got V0 to be -25/3
14. Jun 4, 2012
### Staff: Mentor
That looks better
Be sure to add the appropriate units to the final value.
15. Jun 4, 2012
### NewtonianAlch
Yes, V0 = -8.33V, so that's correct.
With questions involving nodal analysis, I find it easiest to write out the set of node equations really carefully as you're going to need them to solve for the other variables and the slightest error will obviously follow through and then it's a mess having to troubleshoot 3 or 4 equations. Along the way you will see relevant aspects like that Ix = V1/2 which you're going to need to sub in later for your second node equation.
Last edited: Jun 4, 2012
16. Jun 4, 2012
### Lancelot59
Well thanks for the help! This has me off to a good start. I'll just practice the method now.
Last edited: Jun 4, 2012
17. Jun 5, 2012
### Ratch
Lancelot,
Two equations with two unknowns. No need to figure out sub currents.
Ratch
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Last edited: Jun 5, 2012 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7002627849578857, "perplexity": 2154.299163607185}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221213286.48/warc/CC-MAIN-20180818040558-20180818060558-00053.warc.gz"} |
https://gamedev.stackexchange.com/questions/95553/organizing-a-transform-class-to-internally-use-quaternions | # Organizing a Transform class to internally use quaternions
So, I'm interested in building a Transform class similar to the one used in Unity Engine, but in C++. My intent is for it to be user-friendly to change the position, rotation, and scale of a variable by specifying vec3s for each, where the rotation vector specifies Euler angles or some equivalent. However, the math library I have written uses quaternions, and I'd like rotations to be represented internally by quaternions. Since quaternions are a bit difficult to use on their own, or without an axis-angle conversion of some sort, I was wondering what's the best way to do this conversion somewhat efficiently on the fly, so the user doesn't need to fiddle around with quaternions? My current header file is as follows (I haven't written the implementation yet, aside from referencing the private global vectors to the public const ones):
class Transform
{
public:
Transform();
~Transform();
//// Local Information ////
// Position relative to parent
vec3 LocalPosition;
// Scale relative to parent
vec3 LocalScale;
// Rotation about x,y,z axes relative to parent
vec3 LocalRotation;
// Transformation matrix from worldspace to local space
mat4 WorldToLocal() const;
//// Global Information ////
// Position relative to world (const)
const vec3 &WorldPosition;
// Scale relative to world (const)
const vec3 &WorldScale;
// Rotation about x,y,z axes relative to world (const)
const vec3 &WorldRotation;
// Transformation matrix from local space to world space
mat4 LocalToWorld() const;
private:
vec3 _WorldPosition, _WorldScale, _WorldRotation;
// Stores rotation as a quaternion
// ??? Do I need one for global and local? How does this relate to rotation vec3? ???
quat _RotationRaw;
};
All help is greatly appreciated. I'm usually pretty good at solving these issues but I'm at a loss on this one.
Edit: Forgot to mention that I've read over the other GameDev Stack posts on the Unity Transform class, but I couldn't glean any info about this issue from them.
While you're right to use the quaternion as the underlying type for rotation, I'm concerned that you're exposing other fields in C++ which should be handled using getters/setters.
The convention for C++ is to expose get and set methods, and leave the particulars of how the field is handled to the class. That is, excepting TDA since this is a component, something like this:
public:
set_EulerAngles(vec3);
set_Rotation(quat);
set_LocalPosition(vec3);
set_Position(vec3);
// +matching gets...
private:
vec3 _WorldPosition, _WorldScale, _WorldRotation;
quat _Rotation;
and is more like what Unity actually uses underneath:
private void INTERNAL_set_localRotation(ref Quaternion value);
private void INTERNAL_set_rotation(ref Quaternion value);
private void INTERNAL_set_localEulerAngles(ref Vector3 value);
private void INTERNAL_set_localPosition(ref Vector3 value);
private void INTERNAL_set_position(ref Vector3 value);
This frees you up to use alter how things are stored and which math is used later on.
Now, your set_EulerAngles will look like (and I'm using C# here because my C++ is rusty):
var halfPitch = value.x * 0.5f;
var sinPitch = Mathf.Sin(halfPitch);
var cosPitch = Mathf.Cos(halfPitch);
var halfYaw = value.y * 0.5f;
var sinYaw = Mathf.Sin(halfYaw);
var cosYaw = Mathf.Cos(halfYaw);
var halfRoll = value.z * 0.5f;
var sinRoll = Mathf.Sin(halfRoll);
var cosRoll = Mathf.Cos(halfRoll);
_Rotation = new Quaternion();
_Rotation.x = ((cosYaw * sinPitch) * cosRoll) + ((sinYaw * cosPitch) * sinRoll);
_Rotation.y = ((sinYaw * cosPitch) * cosRoll) - ((cosYaw * sinPitch) * sinRoll);
_Rotation.z = ((cosYaw * cosPitch) * sinRoll) - ((sinYaw * sinPitch) * cosRoll);
_Rotation.w = ((cosYaw * cosPitch) * cosRoll) + ((sinYaw * sinPitch) * sinRoll);
and get_EulerAngles would be something like:
var roll = Mathf.Atan2(2*(_Rotation.x*_Rotation.y + _Rotation.z*_Rotation.w),
(1 - 2*(_Rotation.y*_Rotation.y + _Rotation.z*_Rotation.z)));
var pitch = Mathf.Asin(2*(_Rotation.x*_Rotation.z - _Rotation.w*_Rotation.y));
var yaw = Mathf.Atan2(2*(_Rotation.x*_Rotation.w + _Rotation.y*_Rotation.z),
(1 - 2*(_Rotation.z*_Rotation.z + _Rotation.w*_Rotation.w)));
return new Vector3(pitch, yaw, roll);
• You make a good point. I was mostly trying to mimic the Unity syntax to a certain degree, since I don't like Setters/Getters too much, but I definitely see why they're important here. Thank you very much. – dyeo Feb 23 '15 at 23:11 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2814371883869171, "perplexity": 6430.5730511048105}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986654086.1/warc/CC-MAIN-20191014173924-20191014201424-00533.warc.gz"} |
https://www.physicsforums.com/threads/joint-probability-of-partitioned-vectors.763723/ | # Joint probability of partitioned vectors
1. Jul 28, 2014
### scinoob
Hi everybody, I apologize if this question is too basic but I did 1 hour of solid Google searching and couldn't find an answer and I'm stuck.
I'm reading Bishop's Pattern Recognition and Machine Learning and in the second chapter he introduces partitioned vectors. Say, if X is a D-dimensional vector, it can be partitioned like:
X = [Xa, Xb] where Xa is the first M components of X and Xb is the remaining D-M components of X.
I have no problem with this simple concept. Later in the same chapter he talks about conditional and marginal multivariate Gaussian distributions and he uses the notation p(Xa, Xb). I'm trying to understand how certain integrals involving this notation are expanded but I'm actually struggling to understand even this expression. It seems to suggest that we're denoting the joint probability of the components of Xa and the components of Xb. But those are just the components of X anyway!
What is the difference between P(Xa, Xb) and P(X)?
It will be more helpful for me if we considered a more concrete example. Say, X = [X1, X2, X3, X4] and Xa = [X1, X2] while Xb = [X3, X4]. Now, the joint probability P(X) would simply be P(X1, X2, X3, X4), right? What is P(Xa, Xb) in this case?
2. Jul 28, 2014
### mathman
My guess: in later chapters he discusses Xa and Xb as separate entities.
3. Jul 28, 2014
### gill1109
There is no difference between p(Xa, Xb) and p(X), because X = (Xa, Xb). It starts to get interesting when we introduce marginal and conditional probability densities e.g. p(Xa | Xb) and p(Xb). Obviously, p(Xa, Xb) = p(X) = p(Xa | Xb) . p(Xb)
You get p(Xb) from p(X) by integrating out over Xa.
NB use small "p" for probability density. Use capital "P" for probability.
Similar Discussions: Joint probability of partitioned vectors | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.902511715888977, "perplexity": 1285.774250229462}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886123359.11/warc/CC-MAIN-20170823190745-20170823210745-00110.warc.gz"} |
https://www.aimsciences.org/journal/2155-3289/2021/11/4 | American Institute of Mathematical Sciences
ISSN:
2155-3289
eISSN:
2155-3297
All Issues
Numerical Algebra, Control and Optimization
December 2021 , Volume 11 , Issue 4
Select all articles
Export/Reference:
2021, 11(4): 487-493 doi: 10.3934/naco.2020039 +[Abstract](1484) +[HTML](542) +[PDF](308.99KB)
Abstract:
As it is known the equation \begin{document}$A\varphi = f$\end{document} with injective compact operator has a unique solution for all \begin{document}$f$\end{document} in the range \begin{document}$R(A).$\end{document}Unfortunately, the right-hand side \begin{document}$f$\end{document} is never known exactly, so we can take an approximate data \begin{document}$f_{\delta }$\end{document} and used the perturbed problem \begin{document}$\alpha \varphi +A\varphi = f_{\delta }$\end{document} where the solution \begin{document}$\varphi _{\alpha \delta }$\end{document} depends continuously on the data \begin{document}$f_{\delta },$\end{document} and the bounded inverse operator \begin{document}$\left( \alpha I+A \right) ^{-1}$\end{document} approximates the unbounded operator \begin{document}$A^{-1}$\end{document} but not stable. In this work we obtain the convergence of the approximate solution of \begin{document}$\varphi _{\alpha \delta }$\end{document} of the perturbed equation to the exact solution \begin{document}$\varphi$\end{document} of initial equation provided \begin{document}$\alpha$\end{document} tends to zero with \begin{document}$\dfrac{\delta }{\sqrt{\alpha }}.$\end{document}
2021, 11(4): 495-512 doi: 10.3934/naco.2020040 +[Abstract](1851) +[HTML](519) +[PDF](468.75KB)
Abstract:
The direct scheme method is applied to construct an asymptotic approximation of any order to a solution of a singularly perturbed optimal problem with scalar state, controlled via a second-order linear ODE and two fixed end points. The error estimates for state and control variables and for the functional are obtained. An illustrative example is given.
2021, 11(4): 513-531 doi: 10.3934/naco.2020053 +[Abstract](1620) +[HTML](449) +[PDF](449.06KB)
Abstract:
In an attempt to improve theoretical complexity of large-update methods, in this paper, we propose a primal-dual interior-point method for \begin{document}$P_{\ast}\left( \kappa \right)$\end{document}-horizontal linear complementarity problem. The method is based on a class of parametric kernel functions. We show that the corresponding algorithm has \begin{document}$O\left( \left( 1+2\kappa \right) p^{2}n^{\frac{2+p}{2\left( 1+p\right) }}\log \frac{n}{\epsilon }\right)$\end{document} iteration complexity for large-update methods and we match the best known iteration bounds with special choice of the parameter \begin{document}$p$\end{document} for \begin{document}$P_{\ast }\left(\kappa \right)$\end{document}-horizontal linear complementarity problem that is \begin{document}$O\left(\left( 1+2\kappa \right) \sqrt{n}\log n\log \frac{n}{\epsilon }\right)$\end{document}. We illustrate the performance of the proposed kernel function by some comparative numerical results that are derived by applying our algorithm on five kernel functions.
2021, 11(4): 533-554 doi: 10.3934/naco.2020054 +[Abstract](1294) +[HTML](484) +[PDF](443.7KB)
Abstract:
Solving a bi-criterion fractional stochastic programming using an existing multi criteria decision making tool demands sufficient efforts and it is time consuming. There are many cases in financial situations that a nonlinear fractional programming, generated as a result of studying fractional stochastic programming, must be solved. Often management is not in needs of an optimal solution for the problem but rather an approximate solution can give him/her a good starting for the decision making or running a new model to find an intermediate or final solution. To this end, this author introduces a new linear approximation technique for solving a fractional stochastic programming (CCP) problem. After introducing the problem, the equivalent deterministic form of the fractional nonlinear programming problem is developed. To solve the problem, a fuzzy goal programming model of the equivalent deterministic form of the fractional stochastic programming is provided and then, the process of defuzzification and linearization of the problem is presented. A sample test problem is solved for presentation purposes. There are some limitations to the proposed approach: (1) solution obtains from this type of modeling is an approximate solution and, (2) preparation of approximation model of the problem may take some times for the beginners.
2021, 11(4): 555-566 doi: 10.3934/naco.2020055 +[Abstract](1162) +[HTML](399) +[PDF](379.71KB)
Abstract:
The aim of this paper is to study the problem of constrained controllability for distributed parabolic linear system evolving in spatial domain \begin{document}$\Omega$\end{document} using the Reverse Hilbert Uniqueness Method (RHUM approach) introduced by Lions in 1988. It consists in finding the control \begin{document}$u$\end{document} that steers the system from an initial state \begin{document}$y_{_{0}}$\end{document} to a state between two prescribed functions. We give some definitions and properties concerning this concept and then we resolve the problem that relays on computing a control with minimum cost in the case of \begin{document}$\omega = \Omega$\end{document} and in the regional case where \begin{document}$\omega$\end{document} is a part of \begin{document}$\Omega$\end{document}.
2021, 11(4): 567-578 doi: 10.3934/naco.2020056 +[Abstract](982) +[HTML](376) +[PDF](430.99KB)
Abstract:
Biometric characteristics have been used since antiquated decades, particularly in the detection of crimes and investigations. The rapid development in image processing made great progress in biometric features recognition that is used in all life directions, especially when these features recognition is constructed as a computer system. The target of this research is to set up a left foot biometric system by hybridization between image processing and artificial bee colony (ABC) for feature choice that is addressed within artificial image processing. The algorithm is new because of the rare availability of hybridization algorithms in the literature of footprint recognition with the artificial bee colony assessment. The suggested system is tested on a live-captured ninety colored footprint images that composed the visual database. Then the constructed database was classified into nine clusters and normalized to be used at the advanced stages. Features database is constructed from the visual database off-line. The system starts with a comparison operation between the foot-tip image features extracted on-line and the visual database features. The outcome from this process is either a reject or an acceptance message. The results of the proposed work reflect the accuracy and integrity of the output. That is affected by the perfect choice of features as well as the use of artificial bee colony and data clustering which decreased the complexity and later raised the recognition rate to 100%. Our outcomes show the precision of our proposed procedures over others' methods in the field of biometric acknowledgment.
2021, 11(4): 579-611 doi: 10.3934/naco.2020057 +[Abstract](1298) +[HTML](363) +[PDF](3088.97KB)
Abstract:
The assimilation of flexible AC transmission (FACTS) controllers to the existing power network outweigh the numerous alternatives in enhancing the damping behavior for the inter-area /intra-area system oscillations of a power network. This paper provides a rigorous analysis in damping of oscillations in a power network. It utilizes a shunt connected voltage source converter (VSC) based FACTS device to enhance the system operating characteristics. A comprehensive system mathematical modelling has been developed for demonstrating the system behavior under different loading conditions. A novel hybrid augmented grey wolf optimization-particle swarm optimization (AGWO-PSO) is proposed for the coordinated design of controllers static synchronous compensator (STATCOM) and power system stabilizers (PSSs). A multi-objective function, comprising damping ratio improvement and drifting the real part to the left-hand side of S-plane of the system poles, has been developed to achieve the objective and the effectiveness of the proposed algorithms have been analyzed by monitoring the system performance under different loading conditions. Eigenvalue analysis and damping nature of the system states under perturbation have been presented for the proposed algorithms under different loading conditions, and the performance evaluation of the proposed algorithms have been done by means of time of execution and the convergence characteristics.
2021, 11(4): 613-631 doi: 10.3934/naco.2020058 +[Abstract](1636) +[HTML](437) +[PDF](428.7KB)
Abstract:
An interior point modified Nelder Mead method for nonlinearly constrained optimization is described. This method neither uses nor estimates objective function or constraint gradients. A modified logarithmic barrier function is used. The method generates a sequence of points which converges to KKT point(s) under mild conditions including existence of a Slater point. Numerical results are presented that show the algorithm performs well in practice.
2021, 11(4): 633-644 doi: 10.3934/naco.2021001 +[Abstract](1298) +[HTML](372) +[PDF](413.37KB)
Abstract:
In this paper, Lyapunov's artificial small parameter method (LASPM) with continuous particle swarm optimization (CPSO) is presented and used for solving nonlinear differential equations. The proposed method, LASPM-CPSO, is based on estimating the \begin{document}$\varepsilon$\end{document} parameter in LASPM through a PSO algorithm and based on a proposed objective function. Three different examples are used to evaluate the proposed method LASPM-CPSO, and compare it with the classical method LASPM through different intervals of the domain. The results from the maximum absolute error (MAE) and mean squared error (MSE) obtained through the given examples show the reliability and efficiency of the proposed LASPM-CPSO method, compared to the classical method LASPM.
2021, 11(4): 645-663 doi: 10.3934/naco.2021002 +[Abstract](1294) +[HTML](374) +[PDF](372.25KB)
Abstract:
In this work, we have proposed a new approach for solving the linear-quadratic optimal control problem, where the quality criterion is a quadratic function, which can be convex or non-convex. In this approach, we transform the continuous optimal control problem into a quadratic optimization problem using the Cauchy discretization technique, then we solve it with the active-set method. In order to study the efficiency and the accuracy of the proposed approach, we developed an implementation with MATLAB, and we performed numerical experiments on several convex and non-convex linear-quadratic optimal control problems. The obtained simulation results show that our method is more accurate and more efficient than the method using the classical Euler discretization technique. Furthermore, it was shown that our method fastly converges to the optimal control of the continuous problem found analytically using the Pontryagin's maximum principle.
2021, 11(4): 665-676 doi: 10.3934/naco.2021003 +[Abstract](1058) +[HTML](367) +[PDF](374.52KB)
Abstract:
In this paper, we propose a new alternate gradient (AG) method to solve a class of optimization problems with orthogonal constraints. In particular, our AG method alternately takes several gradient reflection steps followed by one gradient projection step. It is proved that any accumulation point of the iterations generated by the AG method satisfies the first-order optimal condition. Numerical experiments show that our method is efficient.
2021, 11(4): 677-685 doi: 10.3934/naco.2021012 +[Abstract](1003) +[HTML](318) +[PDF](333.38KB)
Abstract:
An efficiently preconditioned Newton-like method for the computation of the eigenpairs of large and sparse nonsymmetric matrices is proposed. A sequence of preconditioners based on the Broyden-type rank-one update formula are constructed for the solution of the linearized Newton system. The properties of the preconditioned matrix are investigated. Numerical results are given which reveal that the new proposed algorithms are efficient.
2021 CiteScore: 1.9 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8599947690963745, "perplexity": 684.192832441184}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656104506762.79/warc/CC-MAIN-20220704232527-20220705022527-00690.warc.gz"} |
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### Algebra Tiles Australia
Algebra tiles use an area model to bridge from the concrete to the abstract by showing students various processes in a visual manner that can then be translated into symbolic language.
Members: $25.00 inc.GST Others:$ 31.25 inc.GST
Home > Webshop > Help > Ordering offline
# Other ways to place an order
## By phone
Call the AAMT office on 08 8363 0288
## By fax
Fax your school purchase order or AAMT's order form (see below to download PDF) to 08 8362 9288 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3593175709247589, "perplexity": 7109.343997615516}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187825147.83/warc/CC-MAIN-20171022060353-20171022080353-00443.warc.gz"} |
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