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Designing and making successful automata involves combining materials, mechanisms and magic. Making Simple Automata book explains how to design and construct small scale, simple mechanical devices made for fun. Materials such as paper and card, wood, wire, tinplate and plastics are covered along with mechanisms - levers and linkages, cranks and cams, wheels, gears, pulleys, springs, ratchets and pawls.
This wonderful book is illustrated with examples throughout and explains the six golden rules for making automata alongside detailed step-by-step projects.
BIC: | https://www.brownsbfs.co.uk/Product/Race-Robert/Making-simple-automata/9781847977441 |
Light opened his eyes and panic suddenly hit him, and it hit him hard. Was he really dead? It didn't feel like it. Looking down at his hands and arms, and even feeling his face, it didn't look like he was dead, either. Light almost felt a small relief, until he looked around him. Nothing was around, it was a wasteland. The ground seemed to be made of ashes and the sky was filled with dark clouds.
"No!" Light began to freak out, only to himself. "I can't be dead.. This can't be it.. I had a full life ahead of me. I came so far.." He closed his eyes and hung his head in shame. There had to be someone, something.
So, this is the place that is neither heaven, nor is hell. This, is nothingness..
"There must be something here.. Someone.. Anything.. Anybody.." he tried to tell himself as he ventured into the nothingness. He felt the tears form in his eyes but wiped them away before they could reach his chin. His mind began to flood with memories of his life, who he was, and what led to his premature death. Looking back, he regretted it. Regretted it all, from the very second he picked up the Death Note. It was all meaningless now, all for nothing.
Light kept walking, something told him to continue. As he trudged on, he thought to himself. "So, I really am dead. This is it.. This is eternal nothingness.." He stopped when he thought he saw something fall from the sky. Watching it fall, he took note of where it landed, and went over to investigate.
It was a white envelope with a red seal in the shape of a circle. The seal had an intricate design on it, one where you can feel the texture of the pattern. As he turned the envelope over, he discovered the front had one word, and that word was "Light." So, this was meant for him. Was someone trying to talk to him?
He pondered whether or not he should immediately open the envelope or not. It very well might be the last mail he would ever receive. He sat down, the ground of ash was actually quite a comfortable seat. Placing the envelope in his lap, he took a deep breath and let the nothingness sink in. He finally decided on opening the mail.
Carefully opening the envelope along the sealed top, he wondered what the contents could possibly be, and who it could possibly be from. It was soon discovered that inside the envelope there was a single sheet of paper, about the size of an index card. Or maybe it WAS an index card, Light didn't know and he didn't really care. He now only cared about the possible words that were on the paper.
"When a human enters nothingness, after they die of course, they will spend eternity in this realm completely alone. Almost completely alone, that is. They will be accompanied by one other human being, their soulmate."
"Soulmate?" Light was quite sure how to feel about that. Who could his soulmate be, anyway? He didn't take a single one of his relationships seriously, so he had no clue who this 'soulmate' would be, or if he even had a soul mate. Is that possible? For someone to not have a soulmate?
"I just hope it isn't Misa or Takada.." He thought to himself, while still looking at the pros and cons of things. Maybe even if it was Misa or Takada, it was surely better than spending the rest of forever alone, right? He put the letter in his pocket and got up off the ground to walk aimlessly for a bit. He sure wasn't going to believe it unless he saw someone anyway, so it didn't matter.
There was still a small part of him that wanted to find out if it was real, and if it was, who his soulmate was. Walking aimlessly soon turned into looking around desperately for someone. It seemed like forever with still no luck, but what else was there to do?
Just when he was about to give up for the time being, he saw a spec of something. It was far away, but still visible. Was it a person? Light couldn't tell. He walked towards the figure, excited to find out who, or what, it was. He began to get an idea of who it was, after confirming that it was, in fact, a person. Every step he grew nearer to the person, he grew more sure about who it was.
Standing only about thirty or forty feet away now, he realized the person had his back to Light. There was no way this was happening, it couldn't be. L was the person who was sitting just forty feet in front of him, there was no doubt about his identity. It was confirmed that this person is L.
The letter must be wrong, then. It must not have said soulmate, it must have instead said something like "enemy" or "rival" or something of the nature. Yes, it must have, this must be a punishment in addition to eternal nothingness.
Taking the note out of his pocket, Light reread hadn't been mistaken what the letter said. It still said that a human would be here forever with their 'soulmate.' He examined the whole paper carefully. There was one discovery.
The front of the note still said
"When a human enters nothingness, after they die of course, they will spend eternity in this realm completely alone. Almost completely alone, that is. They will be accompanied by one other human being, their soulmate."
The front of the note was standard, a predetermined note meant to be given to just anyone who belonged in nothingness. But, the back of the letter, that's what was personalized. The back of the note was written especially for Light.
The back of the letter read;
"Light Yagami, Your soulmate is L Lawliet."
Light wondered to himself how someone could possibly consider L and him.. soulmates? If anything, they were enemies. Rivals who had the sole purpose of destroying each other, for their different reasons. It was impossible that they were destined for each other.
That's when it hit him. They really were perfect for one another. Physically, they were complete opposites, two people you'd never expect to even cross each other. But, mentally, they were both very intelligent and both thought very alike.
Now that he really looked at it, Light realized that if they hadn't been on opposing sides, they would have gotten along very well. Light was the first person to match L in intelligence, and the first person L ever could even consider ever calling a friend. And when Light had lost his memories of the Death Note during the Yotsuba Kira case, he couldn't shake this strange feeling he had for L. At the time, he couldn't explain what it was, but now Light was sure that the feeling was love.
When Light was brought out of his thoughts and back into reality, L had turned to face him. L was in his usual sitting position, hugging his knees to his chest. He had a look of happiness on his face, like he'd just won a race. Like he'd just won! The look was no coincidence, L was happy because he knew he'd won. He'd solved his toughest case and Kira was dead, he was now content with this.
L spoke with a certain smugness, in a way that suggested how sure he was of himself.
"I've been waiting for you... Kira."
It didn't matter that it made sense, Light had still never been this shocked in his entire life.. and now his entire death. He was just standing there, speechless. He wasn't going to give L a response, he couldn't. The facts were all there; the fact that he'd been beaten, the fact that the very man who'd been working against him was his soulmate, and the fact that Light would spend eternity with him in this realm filled with nothingness.
L's expression of happiness had faded, and his emotions were now unreadable to Light. But, Light did think he saw the slightest hint of worry in L's eyes. Light tried to speak, but he wasn't quite sure what to say, and L seemed to notice his distress.
"What's the matter, Light?"
Normally, Light would give a cold response. Here they were completely alone surrounded by nothing and here L was, acting as if everything was perfectly fine. For some reason, something stopped Light from responding bitterly. Instead, he figured he'd calm himself and use a more playful tone. With a half smile, Light nonchalantly answered his question.
"Well, for starters, we're dead." | https://www.fanfiction.net/s/8884965/1/For-Eternity |
Daily chart:
Bullish bias of the market was totally confirmed yesterday, when the resistance zone 1751.00-1760.43 was confidently broken. At the same time, as it often occurs after renewal of the highs, gold went to correction, which can have different depth: we might see either a simple retest of the PPZ 1751.00-1760.43 with the following extension of upward momentum (black trajectory) or a full-fledged corrective bearish swing in direction of the support zone 1718.89-1723.44 (blue arrow).
H1-chart:
Within the local structure the high wasn’t renewed and the market exhibits tangible bearish momentum after that. In case support 1759.50 gets broken, the rate might swiftly slide to the PPZ 1744.65-1749.00. Such decline might be actively bought out (red trajectory). But also we need to note the promising demand level 1727.00, which was formed by the bullish Over&Under pattern (black arrow).
Conclusions:
Main scenario: Decline to 1744.65-1749.00 followed by extension of growth in direction 1785.00-1790.00.
Alternative scenario: Decline to 1727.00.
Trading recommendations:
Seeking probable buy signals at 1744.65-1749.00. | https://fortfs.asia/blog/2021/04/16/xauusd-market-technical-outlook-296/ |
---
abstract: 'In this paper, we describe a novel proactive recovery scheme based on service migration for long-running Byzantine fault tolerant systems. Proactive recovery is an essential method for ensuring long term reliability of fault tolerant systems that are under continuous threats from malicious adversaries. The primary benefit of our proactive recovery scheme is a reduced vulnerability window. This is achieved by removing the time-consuming reboot step from the critical path of proactive recovery. Our migration-based proactive recovery is coordinated among the replicas, therefore, it can automatically adjust to different system loads and avoid the problem of excessive concurrent proactive recoveries that may occur in previous work with fixed watchdog timeouts. Moreover, the fast proactive recovery also significantly improves the system availability in the presence of faults.'
author:
- |
Wenbing Zhao\
Department of Electrical and Computer Engineering\
Cleveland State University, 2121 Euclid Ave., Cleveland, OH 44115\
[email protected]
title: 'Proactive Service Migration for Long-Running Byzantine Fault Tolerant Systems[^1]'
---
[**Keywords:**]{} Proactive Recovery, Byzantine Fault Tolerance, Service Migration, Replication, Byzantine Agreement
Introduction
============
We have seen increasing reliance on services provided over the Internet. These services are expected to be continuously available over extended period of time (typically 24x7 and all year long). Unfortunately, the vulnerabilities due to insufficient design and poor implementation are often exploited by adversaries to cause a variety of damages, e.g., crashing of the applications, leaking of confidential information, modifying or deleting of critical data, or injecting of erroneous information into the application data. These malicious faults are often modeled as Byzantine faults [@lamport:byz], and they are detrimental to any online service providers. Such threats can be coped with using Byzantine fault tolerance (BFT) techniques, as demonstrated by many research results [@bft-osdi99; @bft-osdi2000; @bft-acm; @base; @hq; @thema; @oceanstore; @alvisi-bft]. The Byzantine fault tolerance algorithms assume that only a small portion of the replicas can be faulty. When the number of faulty replicas exceeds a threshold, BFT may fail. Consequently, Castro and Liskov [@bft-osdi2000] proposed a proactive recovery scheme that periodically reboots replicas and refreshes their state, even before it is known that they have failed. As long as the number of compromised replicas does not exceed the threshold within a time window that all replicas can be proactively recovered (such window is referred to as window of vulnerability [@bft-acm], or vulnerability window), the integrity of the BFT algorithm holds and the services being protected remain highly reliable over the long term.
However, the reboot-based proactive recovery scheme has a number of issues. First, it assumes that a simple reboot ([[*i.e.,$\ $*]{}]{}power cycle the computing node) can successfully repair a compromised node, which might not be the case, as pointed out in [@bftlls]. Second, even if a compromised node can be repaired by a reboot, it is often a prolonged process (typically over 30$s$ for modern operating systems). During the rebooting step, the BFT services might not be available to its clients ([[*e.g.,$\ $*]{}]{}if the rebooting node happens to be a nonfaulty replica needed for the replicas to reach a Byzantine agreement). Third, there lacks coordination among replicas to ensure that no more than a small portion of the replicas (ideally no more than $f$ replicas in a system of $3f+1$ replicas to tolerate up to $f$ faults) are undergoing proactive recovery at any given time, otherwise, the services may be unavailable for extended period of time. The static watchdog timeout used in [@bft-acm] also contributes to the problem because it cannot automatically adapt to various system loads. The staggered proactive recovery scheme in [@bft-acm] is not sufficient to prevent this problem from happening.
In this paper, we present a novel proactive recovery scheme based on service migration, which addresses all these issues. Our proactive recovery scheme requires the availability of a pool of standby computing nodes in addition to the active nodes where the replicas are deployed. The basic idea is outlined below. Periodically, the replicas initiate a proactive recovery by selecting a set of active replicas, and a set of target standby nodes for a service migration. At the end of the service migration, the source active nodes will be put under a series of preventive sanitizing and repairing steps (such as rebooting and swapping in a clean hard drive with the original system binaries) before they are assigned to the pool of standby nodes, and the target nodes are promoted to the group of active nodes. The unique feature of this design is that the sanitizing and repairing step is carried out [*off the critical path of proactive recovery*]{} and consequently, it has minimum negative impact on the availability of the services being protected.
This paper makes the following research contributions:
- We propose a novel migration-based proactive recovery scheme for long-running Byzantine fault tolerant systems. The scheme significantly reduces the recovery time, and hence, the vulnerability window, by moving the time-consuming replica sanitizing and repairing step off the critical path.
- Our proactive recovery scheme ensures a coordinated periodical recovery, which prevents harmful excessive concurrent proactive recoveries.
- We present a comparison study on the performance of the reboot-based and our migration-based proactive recovery schemes in the presence of faults, both by analysis and by experiments.
System Model
============
We assume a partially asynchronous distributed system in that all message exchanges and processing related to proactive recovery can be completed within a bounded time. This bound can be initially set by a system administrator and can be dynamically adjusted by the recovery mechanisms. However, the safety property of the Byzantine agreement on all proactive recovery related decisions (such as the selection of source nodes and destination nodes for service migration) is maintained without any system synchrony requirement.
We assume the availability of a pool of nodes to serve as the standby nodes for service migration, in addition to the $3f+1$ active nodes required to tolerate up to $f$ Byzantine faulty replicas. The pool size is large enough to repair damaged nodes while enabling frequent service migration for proactive recovery. Furthermore, both active nodes and standby nodes can be subject to malicious attacks (in addition to other non-malicious faults such as hardware failures). However, we assume that the rate of successful attacks on the standby nodes is much smaller than that on active nodes, [[*i.e.,$\ $*]{}]{}the tolerated successful attack rate on active nodes is determined by the vulnerability window the system can achieve, and the tolerated successful attack rate on standby nodes is determined by the repair time. The allowed repair time can be much larger than the achievable vulnerability window given a sufficiently large pool of standby nodes. If the above assumptions are violated, there is no hope to achieve long-term Byzantine fault tolerance.
We assume the existence of a trusted configuration manager, as described in [@rosebud; @bftlls], to manage the pool of standby nodes, and to assist service migration. Example tasks include frequently probing and monitoring the health of each standby node, and repairing any faulty node detected. We will not discuss the mechanisms used by the manager to carry out such tasks, they are out of the scope of this paper.
Other assumptions regarding the system is similar to those in [@bft-acm] and they are summarized here. All communicating entities (clients, replicas and standby nodes) use a secure hash function such as SHA1 to compute the digest of a message and use the message authentication codes (MACs) to authenticate messages exchanged, except for key exchange messages, which are protected by digital signatures. For point to point message exchanges, a single MAC is included in each message, while multicast messages are protected by an authenticator [@authenticator]. Each entity has a pair of private and public keys. The active and standby nodes each is equipped with a secure coprocessor and sufficiently large read-only memory. In these nodes, the private key is stored in the coprocessor and all digital signing and verification is carried out by the coprocessor without revealing the private key. The read-only memory is used to store the execution code for the server application and the BFT framework. We do not require the presence of a hardware watchdog timer because of the coordination of migration and the existence of a trusted configuration manager.
Finally, we assume that an adversary is computational bound so that it cannot break the above authentication scheme.
Proactive Service Migration Mechanisms
======================================
The proactive service migration mechanisms collectively ensure the following objectives:
1. To ensure that correct active replicas have a consistent membership view of the available standby nodes.
2. To determine when to migrate and how to initiate a migration.
3. To determine the set of source and target nodes for migration.
4. To transfer a correct copy of the system state to the new replicas.
5. To notify the clients the new membership after each proactive recovery.
The first objective is clearly needed because otherwise the replicas cannot possibly agree on the set of target nodes for migration. The second and third objectives are critical to ensure a coordinated periodic proactive recovery. The fourth objective is obviously necessary for the new replicas to start from a consistent state. The fifth objective is essential to ensure that the clients know the correct membership of the server replicas so that they do not accept messages from possibly faulty replicas that have been migrated out of active executing duty, and they can send requests to the new replicas.
Standby Nodes Registration
--------------------------
Each standby node is controlled by the trusted configuration manager and is undergoing constant probing and sanitization procedures such as reboot. If the configuration manager suspects the node to be faulty and cannot repair it automatically, a system administrator might be called in to manually fix the problem. Each time a standby node completes a sanitization procedure, it notifies the active replicas with a [join-request]{} message in the form of $<$[join-request]{}$, l, i_s$$>$$_{\sigma_{i_s}}$, where $l$ is the counter value maintained by the secure coprocessor of the standby node, $i_s$ is the identifier of the standby node, and $\sigma_{i_s}$ is the authenticator. The registration protocol is illustrated in Figure \[joinfig\].
=3.0in
An active replica accepts the [join-request]{} if it has not accepted one from the same standby node with the same or greater $l$. The [join-request]{} message, once accepted by the primary, is ordered the same way as a regular message with a sequence number $n_r$, except that the primary also assigns a timestamp as the join time of the standby node and piggybacks it with the ordering messages. The total ordering of the [join-request]{} is important so that all active nodes have the same membership view of the standby nodes. The significance of the join time will be elaborated later in this section.
When a replica executes the [join-request]{} message, it sends a [join-approved]{} message in the form of $<$[join-approved]{}$, l, n_r$$>$$_{\sigma_i}$ to the requesting standby node. The requesting standby node must collect $2f+1$ consistent [join-approved]{} messages with the same $l$ and $n_r$ from different active replicas. The standby node then initiates a key exchange with all active replicas for future communication.
A standby node might go through multiple rounds of proactive sanitization before it is selected to run an active replica. The node sends a new [join-request]{} reconfirming its membership after each round of sanitization. The active replicas subsequently updates the join time of the standby node.
It is also possible that the configuration manager deems a registered standby node as faulty and it requires a lengthy repair, in which case, the configuration manager deregisters the faulty node from active replicas by sending a [leave-request]{}. The [leave-request]{} is handled by the active replicas in a similar way as that for [join-request]{}. In the unlikely case that the faulty standby node has been selected as the new active node, the mechanisms react in the following ways: (1) if the migration is still ongoing when the [leave-request]{} arrives, it is aborted and restarted with a different set of target standby nodes, and (2) if the migration has been completed, an on-demand service migration will be initiated to swap out the faulty node. The on-demand service migration mechanism is rather similar to the proactive migration mechanism, as will be discussed in Section \[ondemandsec\].
Proactive Service Migration
---------------------------
#### When and How to Initiate a Proactive Service Migration?
The proactive service migration is triggered by the software-based migration timer maintained by each replica. The timer is reset and restarted at the end of each round of migration. (An on-demand service migration may also be carried out upon the notification from the configuration manager, as mentioned in the previous subsection.)
How to properly initiate a proactive service migration, however, is tricky. We cannot depend on the primary to initiate a proactive recovery because it might be faulty. Therefore, the migration initiation must involve all replicas.
On expiration of the migration timer, a replica chooses a set of $f$ active replicas, and a set of $f$ standby nodes, and multicasts an [init-migration]{} request to all other replicas in the form $<$[init-migration]{}$, v, l, S, D, i$$>$$_{\sigma_i}$, where $v$ is the current view, $l$ is the migration number (determined by the number of successful migration rounds recorded by replica $i$), $S$ is the set of identifiers for the $f$ active replicas to be migrated, $D$ is the set of identifiers for the $f$ standby nodes as the targets of the migration, $i$ is the identifier for the sending replica, and $\sigma_i$ is the authenticator for the message.
On receiving an [init-migration]{} message, a replica $j$ accepts the message and stores the message in its data structure provided that the message carries a valid authenticator, it has not accepted an [init-migration]{} message from the same replica $i$ in view $v$ with the same or higher migration number, and the replicas in $S$ and $D$ are consistent with the sets determined by itself according to the selection algorithm (to be introduced next).
Each replica waits until it has collected $2f$$+$$1$ [init-migration]{} messages from different replicas (including its own [init-migration]{} message) before it constructs a [migration-request]{} message. The [migration-request]{} message has the form $<$[migration-request]{}$, v, l, S, D$$>$$_{\sigma_p}$. The primary, if it is correct, should place the [migration-request]{} message at the head of the request queue and order it immediately. The primary orders the [migration-request]{} in the same way as that for a normal request coming from a client, except that (1) it does not batch the [migration-request]{} message with normal requests, and (2) it piggybacks the [migration-request]{} and the $2f$$+$$1$ [init-migration]{} messages (as proof of validity of the migration request) with the [pre-prepare]{} message. The reason for ordering the [migration-request]{} is to ensure a consistent synchronization point for migration at all replicas. An illustration of the migration initiation protocol is shown as part of Figure \[migrationfig\].
Each replica starts a view change timer when the [migration-request]{} message is constructed (just like when it receives a normal request) so that a view change will be initiated if the primary is faulty and does not order the [migration-request]{} message. The new primary, if it is not faulty, should continue this round of proactive migration.
In this work, we choose not to initiate a view change when the primary is migrated if the state is smaller than a tunable parameter (100KB is used in our experiment). For larger state ([[*i.e.,$\ $*]{}]{}when the cost of state transfer is more than that of the view change), the primary multicasts a [view-change]{} message before it is migrated, similar to [@bft-acm].
=3.0in
#### Migration Set Selection.
The selection of the set of active replicas to be migrated is relatively straightforward. It takes four rounds of migration (each round for $f$ replicas) to proactively recover all active replicas at least once. The replicas are recovered according to the reverse order of their identifiers, similar to that used in [@bft-acm]. For example, for the very first round of migration, replicas with identifiers of $3f,3f-1,...,2f+1$ will be migrated, and this will be followed by replicas with identifiers of $2f,2f-1,...,f+1$ in the second round, replicas with identifiers of $f,f-1,...,1$ in the third round, and finally replicas with identifiers of $0,3f,...2f+2$ in the fourth round. (The example assumed $f>2$. It is straightforward to derive the selections for the cases when $f=1,2$.) The selection is deterministic and can be easily computed based on the migration number. Note that the migration number constitutes part of middleware state and will be transfered to all recovering replicas. The selection is independent of the view the replicas are in.
The selection of the set of standby nodes as the target of migration is based on the elapsed time since the standby nodes were last sanitized. That is why each replica keeps track of the join time of each standby nodes. For each round of migration, the $f$ standby nodes with the least elapsed time will be chosen. This is out of consideration that the probability of these nodes to be compromised at the time of migration is the least (assuming brute-force attacks by adversaries).
#### Migration Synchronization Point Determination.
It is important to ensure all (correct) replicas to use the same synchronization point when performing the service migration. This is achieved by ordering the [migration-request]{} message. The primary starts to order the message by sending a [pre-prepare]{} message for the [migration-request]{} to all backups, as described previously.
A backup verifies the piggybacked [migration-request]{} in a similar fashion as that for the [init-migration]{} message, except now the replica must check that it has received all the $2f$$+$$1$ init-migration messages that the primary used to construct the [migration-request]{}, and the sets in $S$ and $D$ match those in the [init-migration]{} messages. The backup requests the primary to retransmit any missing [init-migration]{} messages. The backup accepts the [pre-prepare]{} message for the [migration-request]{} provided that the [migration-request]{} is correct and it has not accepted another [pre-prepare]{} message for the same sequence number in view $v$. From now on, the replicas executes according to the three-phase BFT algorithm [@bft-acm] as usual until they commit the [migration-request]{}.
#### State Transfer.
When it is ready to execute the [migration-request]{}, a replica $i$ takes a checkpoint of its state (both the application and the BFT middleware state), and multicasts a [migrate-now]{} message to the $f$ standby nodes selected. The [migrate-now]{} message has the form $<$[migrate-now]{}$, v, n, C, P, i$$>$$_{\sigma_i}$, where $n$ is the sequence number assigned to the [migration-request]{}, $C$ is the digest of the checkpoint, and $P$ contains $f$ tuples. Each tuple contains the identifiers of a source-node and target-node pair $<$$s, d$$>$. The standby node $d$, once completes the proactive recovery procedure, assumes the identifier $s$ of the active node it replaces. A replica sends the actual checkpoint (together with all queued request messages, if it is the primary) to the target nodes in separate messages.
If a replica belongs to the $f$ nodes to be migrated, it performs the following additional actions: (1) it stops accepting new request messages, and (2) it reports to the trusted configuration manager as a candidate standby node. This replica is then handed over to the control of the configuration manager for sanitization.
Before a standby node can be promoted to run an active replica, it must collect $2f$$+$$1$ consistent [migrate-now]{} messages with the same sequence number and the digest of the checkpoint from different active replicas. Once a standby node obtains a stable checkpoint, it applies the checkpoint to its state and starts to accept clients’ requests and participate the BFT algorithm as an active replica.
New Membership Notification
---------------------------
One can envisage that a fault node might want to continue sending messages to the active replicas and the clients, even if it has been migrated, before it is sanitized by the configuration manager. It is important to inform the clients the new membership so that they can ignore such messages sent by the faulty replica. The membership information is also important for the clients to accept messages send by new active replicas, and to send messages to these replicas. This is guaranteed by the new membership notification mechanism.
The new membership notification is performed in a lazy manner to improve the performance unless a new active replica assumes the primary role, in which case, the notification is sent immediately to all known clients (so that the clients can send their requests to the new primary). Furthermore, the notification is sent only by the existing active replicas ([[*i.e.,$\ $*]{}]{}not the new active replicas because the clients do not know them yet). Normally, the notification is sent to a client only after the client has sent a request that is ordered after the [migration-request]{} message, [[*i.e.,$\ $*]{}]{}the sequence number assigned to the client’s request is bigger than that of the [migration-request]{}.
The notification message has the form $<$[new-membership]{}$, v, n, P, i$$>$$_{\sigma_i}$ (basically the same as the [migration-now]{} message without the checkpoint), where $v$ is the view in which the migration occurred, and $n$ is the sequence number assigned to the [migration-request]{}, and $P$ contains the tuples of the identifiers for the replicas in the previous and the new membership. Note all active replicas should have the information.
When a client collects $f+1$ consistent [new-membership]{} messages from different replicas, it updates its state accordingly and starts to accept replies from, and to send requests to, the new replicas.
On-Demand Migration {#ondemandsec}
-------------------
One demand migration can happen when the configuration manager detects a node to be faulty after it has been promoted to run an active replica. It can also happen when replicas have collected solid evidence that one or more replicas are faulty, such as a lying primary. The on-demand migration mechanism is rather similar to that for proactive recovery, with only two differences: (1) The migration is initiated on-demand, rather than by a migration timeout. However, replicas still must exchange the [init-migration]{} messages before the migration can take place; (2) The selection procedure for the source node is omitted because the nodes to be swapped out are already decided, and the same number of target nodes are selected accordingly.
Benefits of Proactive Service Migration {#benefitsec}
=======================================
Reduced Vulnerability Window
----------------------------
The primary benefit of using the migration-based proactive recovery is a reduced vulnerability window. The term vulnerability window (or window of vulnerability) $T_v = 2T_k + T_r$ is introduced in [@bft-acm]. Here $T_r$ is the time elapsed between when a replica becomes faulty and when it fully recovers from the fault, and $T_k$ is the key refreshment period. As long as no more than $f$ replicas become faulty during the window of $T_v$, the invariants for Byzantine fault tolerance will be preserved.
In the reboot-based proactive recovery scheme, the vulnerability window $T_v^{pr}$ is characterized to be $2T_k + T_w^{pr} + R_n$, as shown in the upper half of Figure \[windowfig\], where $T_w^{pr}$ is the watchdog timeout, $R_n$ is the recovery time for a nonfaulty replica under normal load conditions. The dominating factors for recovery time include $T_{reboot}$, the reboot time, and $T_s^{pr}$, the time it takes to save, restore and verify the replica state. The watchdog timeout $T_w^{pr}$ is set roughly to $4R_n$ to enable a staggered proactive recovery of $f$ replicas at a time.
=3.0in
The composition of the vulnerability window for the migration-based proactive recovery is shown in the lower half of Figure \[windowfig\]. The time intervals specific to migration-based proactive recovery is labeled by the $pm$ superscript. Because the migration is coordinated in this recovery scheme, no watchdog timer is used and the term $T_w^{pm}$ is now interpreted as the migration timer, [[*i.e.,$\ $*]{}]{}the time elapsed between two consecutive rounds of migrations of $f$ replicas each. This is very different from the watchdog timeout $T_w^{pr}$, which is statically configured prior to the start of each replica. Because the recovery time in the migration-based proactive recovery is much shorter than that in the reboot-based recovery, and the migration is coordinated, it takes much shorter time to fully recovery all active replicas once. Hence, $T_r$ can be much shorter for the migration-based recovery, which leads to a smaller vulnerability window.
Increased Availability in the Presence of Faults
------------------------------------------------
Under fault-free condition, neither the reboot-based nor the migration-based recovery scheme has much negative impact to the runtime performance unless the state is very large, as shown in the experimental data in [@bft-acm] and in Section \[perfsec\] of this paper. However, in the presence of faulty nodes, the system availability can be reduced significantly in the reboot-based proactive recovery scheme, while the reduction in availability remains small in our migration-based recovery scheme.
The see the benefit of the migration-based proactive recovery regarding the system availability in the presence of faults, we consider a specific case when the number of faulty nodes is $f$ and $f=1$. While developing a thorough analytical model is certainly desirable, it is out of the scope of this paper.
We assume that there are $f=1$ faulty replica at the beginning of the set of four rounds of migration to eradicate it. (Recall that we assume that at most $f$ replicas can be compromised in one vulnerability window, which constitutes four rounds proactive recovery of $f$ replicas at a time and $2T_k$, therefore, it is not possible to end up with more than $f$ faulty replicas with this assumption.) We further assume that the proactive recovery rounds after the removal of the faulty replica has no negative impact on the system availability, and so does the case when the faulty replica is recovered in the same round of recovery. We also ignore the differences between the recovery time of a normal replica and that of a faulty one.
Since $f=1$, the faulty node must be recovered in one of the four rounds of recovery. Assuming that the faulty node is chosen randomly, it is recovered in even probability in either of the four rounds, [[*i.e.,$\ $*]{}]{}$P_i=0.25$, where $i=0,1,2,3$. If the faulty replica is recovered in the first round of recovery, there is no reduction of system availability $q_0$ ([[*i.e.,$\ $*]{}]{}$q_0=1$). If the faulty replica is recovered in round $i$, where $i=1,2,3$, the system will not be available while a replica is recovering during each round because there will be insufficient number of correct replicas until the recovery is completed, and hence, the system availability $q_i$ in this case will be determined as $$q_i=P_i\frac{T_v-iR_n}{T_v}$$ Therefore, the total system availability is $$q=\sum_{i=0}^{3}q_i=0.25\sum_{i=0}^{3}\frac{T_v-iR_n}{T_v}$$
For the reboot-based recovery, $R_n\approx T_{reboot}+T_{s}^{pr}$, and for the migration-based recovery, $R_n\approx T_{s}^{pm}$. It is not unreasonable to assume $T_s^{pr}\approx T_s^{pm}$ because the network bandwidth is similar to the disk IO bandwidth in modern general-purpose systems. As shown in Figure \[avaifig\](a), the migration-based recovery can achieve much better system availability if the reboot time $T_{reboot}$ is large, which is generally the case. Furthermore, as indicated in Figure \[avaifig\](b), for the range of vulnerability window considered, the system availability is consistently higher for the migration-based proactive recovery than that for the reboot-based proactive recovery.
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Performance Evaluation {#perfsec}
======================
The proactive service migration mechanisms have been implemented and incorporated into the BFT framework developed by Castro, Rodriguos and Liskov [@bft-osdi99; @bft-osdi2000; @bft-acm; @base]. Due to the potential large state, an optimization has been made, similar to the optimization on the reply messages in the original BFT framework, [[*i.e.,$\ $*]{}]{}instead of every replica sends its checkpoint to the target nodes of migration, only one actually sends the full checkpoint. The target node can verify if the copy of the full checkpoint is correct by comparing the digest of the checkpoint with the digests received from the replicas. If the checkpoint is not correct, the target node asks for a retransmission from other replicas.
Similar to [@bft-acm], the performance measurements are carried out in general-purpose servers without hardware coprocessors. The related operations are simulated in software. Furthermore, the trusted configuration manager is not developed as this is one of the no goals of this paper. The motivation of the measurements is to assess the runtime performance of the proactive service migration scheme for practical use.
Our testbed consists of a set of Dell SC440 servers connected by a 100 Mbps local-area network. Each server is equipped with a single Pentium dual-core 2.8GHz CPU and 1GB of RAM, and runs the SuSE Linux 10.2 operation system. The micro-benchmarking example included in the original BFT framework is adapted as the test application. The request and reply message length is fixed at 1KB, and each client generates requests consecutively in a loop without any think time. Each server replica simply echoes the payload in the request back to the client.
Four active nodes, four standby nodes, and up to eight client nodes are used in the experiment. This setup can tolerate a single Byzantine faulty replica. The service migration interval is set to 70$s$, corresponding to the minimum possible vulnerability window for a key exchanged interval of 15s and a maximum recovery time (for a single replica) of 10$s$.
To characterize the runtime cost of the service migration scheme, we measure the recovery time for a single replica with and without the presence of clients, and the impact of proactive migration on the system performance perceived by clients. The recovery time is determined by measuring the time elapsed between the following two events: (1) the primary sending the [pre-prepare]{} message for the [migration-request]{}, and (2) the primary receiving a notification from the target standby node indicating that it has collected and applied the latest stable checkpoint. (The notification message is not part of the recovery protocol. It is inserted solely for the purpose of performance measurements.) We refer to this time interval as the service migration latency. The impact on the system performance is measured at the client by counting the number of calls it has made during one vulnerability window, with and without proactive migration-based recovery.
The measurement results are summarized in Figure \[perfig\]. Figure \[perfig\](a) shows the service migration latency for various state sizes (from 100KB to about 10MB). It is not surprising to see that the cost of migration is limited by the bandwidth available (100Mbps) because in our experiment, the time it takes to take a local checkpoint (to memory) and to restore one (from memory) is negligible. This is intentional for two reasons: (1) the checkpointing and restoration cost is very application dependent, and (2) such cost is the same regardless of the proactive recovery schemes used.
Furthermore, we measure the migration latency as a function of the system load in terms of the number of concurrent clients. The results are shown in Figure \[perfig\](b). As can be seen, the migration latency increases more significantly for larger state when the system load is higher. When there are eight concurrent clients, the migration latency for a state size of 5MB exceeds 10$s$, which is the maximum recovery time we assumed in our availability analysis. This observation suggests the need for dynamic adjusting of some parameters related to the vulnerability window, in particular, the watchdog timeout used in the reboot-based recovery scheme. If the watchdog timeout is too short for the system to go through four rounds of proactive recovery (of $f$ replicas at a time), there will be more than $f$ replicas going through proactive recoveries concurrently, which will decrease the system availability, even without any fault. Our migration-based proactive recovery does not suffer from this problem. Due to the use of coordinated recovery, when the system load increases, the vulnerability window automatically increases.
Figure \[perfig\](c) shows the performance impact of proactive service migration as perceived by a single client. In the experiment, we choose to use the parameters consistent with those used in the availability analysis (for migration-based recovery), [[*i.e.,$\ $*]{}]{}key exchange period of 15$s$, maximum recovery time of 10$s$, and a vulnerability window of 70$s$. As can be seen, the impact of proactive migration on the system performance is quite acceptable. For a state smaller than 1MB, the throughput is reduced only by 10% or less comparing with the no-proactive-recovery case. In addition, we have measured the migration performance in the presence of one (crash) faulty replica (the recovering recovery is different from the crashed replica). The system throughput degradation is similar to that in fault-free condition. Note that when there are only three correct replicas, the system throughput is reduced even without proactive migration, as shown in the figure.
Related Work
============
Ensuring Byzantine fault tolerance for long-running systems is an extremely challenging task. The pioneering work is carried out by Castro and Liskov. In [@bft-acm], they proposed a reboot-based proactive recovery scheme as a way to repair compromised nodes periodically. The work is further extended by Rodrigues and Liskov in [@bftlls]. They proposed additional infrastructure support and related mechanisms to handle the cases when a damaged replica cannot be repaired by a simple reboot. Our work is inspired by both work. The novelty and the benefits of our service-migration scheme over the reboot-based proactive recovery scheme have been elaborated in Section \[benefitsec\].
Other related work includes [@pallemulle]. In [@pallemulle], Pallemulle [*et al.*]{} extended the BFT algorithm to handle replicated clients and introduced another Byzantine agreement (BA) step to ensure that all replicated clients receive the same set of replies. It was claimed that the mechanisms can also be used to perform online upgrading, which is important for long-running applications and not addressed in our work. However, it is not clear if the BA step on the replies is useful, while incurring significantly higher cost. If there are more than $f$ compromised server replicas, the integrity of the service is already broken, in which case, there is no use for the client replicas to receive the same faulty reply.
Finally, the reliance on extra nodes beyond the $3f+1$ active nodes in our scheme may somewhat relates to the use of $2f$ additional witness replicas in the fast Byzantine consensus algorithm [@fbc]. However, the extra nodes are needed for completely different purposes. In our scheme, they are required for proactive recovery for long-running Byzantine fault tolerant systems. In [@fbc], however, they are needed to reach Byzantine consensus in fewer message delays.
Conclusion
==========
In this paper, we presented a novel proactive recovery scheme based on service migration for long-running Byzantine fault tolerant systems. We described in detail the challenges and mechanisms needed for our migration-based proactive recovery to work. The migration-based recovery scheme has a number of unique benefits over previous work, including a smaller vulnerability window by shifting the time-consuming repairing step out of the critical recovery path, higher system availability under faulty conditions, and self-adaptation to different system loads. We validated these benefits both analytically and experimentally. For future work, we plan to investigate the design and implementation of the trusted configuration manager, in particular, the incorporation of the code attestation methods [@code1; @code2] into the fault detection mechanisms, and the application of the migration-based recovery scheme to practical systems such as networked file systems.
[10]{}
M. Castro and B. Liskov. Authenticated [Byzantine]{} fault tolerance without public-key cryptography. Technical Report MIT-LCS-TM-589, MIT, June 1999.
M. Castro and B. Liskov. Practical [Byzantine]{} fault tolerance. In [*Proceedings of the Third Symposium on Operating Systems Design and Implementation*]{}, New Orleans, USA, February 1999.
M. Castro and B. Liskov. Proactive recovery in a [Byzantine]{}-fault-tolerant system. In [*Proceedings of the Third Symposium on Operating Systems Design and Implementation*]{}, San Diego, USA, October 2000.
M. Castro and B. Liskov. Practical [Byzantine]{} fault tolerance and proactive recovery. , 20(4):398–461, November 2002.
M. Castro, R. Rodrigues, and B. Liskov. : Using abstraction to improve fault tolerance. , 21(3):236–269, August 2003.
B. Chen and R. Morris. Certifying program execution with secure processors. In [*Proceedings of the 9th Workshop on Hot Topics in Operating Systems*]{}, May 2003.
J. Cowling, D. Myers, B. Liskov, R. Rodrigues, and L. Shrira. HQ Replication: A Hybrid quorum protocol for Byzantine fault tolerance. In [*Proceedings of the Seventh Symposium on Operating Systems Design and Implementations*]{}, Seattle, Washington, November 2006.
T. Garfinkel, B. Pfaff, J. Chow, M. Rosenblum, and D. Boneh. Terra: A virtual machine-based platform for trusted computing. In [*Proceedings of the 19th Symposium on Operating System Principles*]{}, October 2003.
L. Lamport, R. Shostak, and M. Pease. The [B]{}yzantine generals problem. , 4(3):382–401, July 1982.
J. Martin and L. Alvisi. Fast Byzantine Consensus. , 3(3):202–215, July-September 2006.
M. Merideth, A. Iyengar, T. Mikalsen, S. Tai, I. Rouvellou, and P. Narasimhan. Thema: Byzantine-fault-tolerant middleware for web services applications. In [*Proceedings of the IEEE Symposium on Reliable Distributed Systems*]{}, pages 131–142, 2005.
S. Pallemulle, L. Wehrman and K. Goldman. Byzantine fault tolerant execution of long-running distributed applications. In [*Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Systems*]{}, Dallas, TX, November 2006.
S. Rhea, P. Eaton, D. Geels, H. Weatherspoon, B. Zhao, and J. Kubiatowicz. Pond: the [OceanStore]{} prototype. In [*Proceedings of the 2nd USENIX Conference on File and Storage Technologies*]{}, March 2003.
R. Rodrigues and B. Liskov. Rosebud: A scalable Byzantine fault-tolerant storage architecture. Technical Report MIT CSAIL TR/932, MIT, December 2003.
R. Rodrigues and B. Liskov. Byzantine fault tolerance in long-lived systems. In [*Proceedings of the 2nd Workshop on Future Directions in Distributed Computing*]{}, June 2004.
J. Yin, J.-P. Martin, A. Venkataramani, L. Alvisi, and M. Dahlin. Separating agreement from execution for byzantine fault tolerant services. In [*Proceedings of the ACM Symposium on Operating Systems Principles*]{}, pages 253–267, Bolton Landing, NY, USA, 2003.
[^1]: This research has been supported in part by Department of Energy Contract DE-FC26-06NT42853, and by Cleveland State University through a Faculty Research Development award.
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Conservation plan could help endangered primates in Africa
A project co-led by the University of the West of England (UWE Bristol), Bristol Zoo and West African Primate Conservation Action is set to protect nine species of primate found across Africa. A five-year plan that will be sent to the International Union for the Conservation of Nature (IUCN), and which begins in 2020, sets out measures to protect the endangered Mangadrills.
Mangadrills include nine groups of African monkeys: seven within the genus Cercocebus, also known as mangabeys, and three within Mandrillus, including the mandrill and the two sub-species described as drills. These primates inhabit an area that stretches from Senegal and Gabon in West Africa, all the way to the Tana River Delta in Kenya. Yet despite the wide range of their habitats, they are among some of the world's most threatened monkeys.
Dr. David Fernandez, senior lecturer in conservation science at UWE Bristol who is co-leading the project, said: "These species are one of the least known primates, as there are very few people working on them. They are classed as endangered, except one critically endangered and one vulnerable by the IUCN. Although we know that in most cases their numbers are going down, for many we still don't know exactly where the populations are or how many are left."
The plan lists a set of actions that could help conserve these monkeys, which live in forest areas. Although the measures are still being finalized, one could be to protect the Bioko drill (Mandrillus leucophaeus poensis) species from hunters on Bioko Island, in Equatorial Guinea, by blocking off access routes to protected areas, which are used by hunters.
Said Dr. Fernandez: "Most hunters enter the Caldera de Luba Scientific Reserve, a protected area in the South of Bioko where most Bioko drills live, using the only existing paved road. Setting up a checkpoint on it would help control poaching in that area and might constitute a plan that is achievable and could be highly effective."
Another suggested action is to go into communities where primates raid sugar cane crops and are sometimes killed in retaliation. A solution, as set out in the plan, is to help communities to build appropriate fences to prevent this from happening.
As well as identifying what needs to happen to protect these animals, another goal of the action plan is to highlight the existence and plight of these animals.
One action is to set up ecotourism tours in locations like Bioko Island, where the primates have their habitats. Tourists would be able to spend the night in a tropical forest and go with local guides to view the monkeys up close.
Dr. Grainne McCabe, head of Field Conservation and Science at Bristol Zoological Society, said: "This action plan is a genuine step forward in trying to save Mangadrill monkeys and we are really pleased to be working with the University of the West of England.
"Together we hope to promote awareness of these threatened species and encourage researchers, conservationists and governments to take the necessary actions to protect them."
Citation:
Conservation plan could help endangered primates in Africa (2019, September 3)
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Liquid crystal (LC) displays are widely used for laptop computers, handheld calculators, digital watches, and similar devices in which information must be displayed to a viewer. In many applications, the displays incorporate a backlight to provide the light necessary to view the display when ambient light entering the display and reflected back out of the display is insufficient.
Backlight systems typically incorporate a light source and a light guide to direct light from the source and uniformly spread it over the display. Traditionally, light guides have been provided of light transparent material which propagate light along their length through total internal reflection. The light is typically reflected off of the back surface of the light guide and towards the front surface at angles which allow it to exit the front surface of the light guide. Various reflection mechanisms are used to distribute the light exiting the guide uniformly including reflective dots, channels, facets etc.
Backlight systems which use non-collimated light sources such as fluorescent lamps, etc. also typically incorporate at least two reflectors. A lamp cavity mirror is typically used to reflect light exiting the light source in a direction away from the light guide back towards the guide. This reflector can be specular or diffuse, although it is typically specular.
A second reflector is provided proximate the back surface of the light guide to reflect light escaping from the back surface of the light guide and redirect it towards the front surface of the light guide where it can be transmitted to the viewer. These reflectors are typically constructed of a reflective white coating that also diffuse the reflected light over a Lambertian distribution.
A primary disadvantage with the conventional reflectors used in the lamp cavity and at the back surface of the light guide is, however, their relatively high absorptivities and high transmission of incident light. Typical reflectors will absorb or transmit about 4 to about 15% of the light incident upon them. The absorbed light is, of course, not available to the viewer, thereby degrading performance of the backlight.
The absorptive losses are, of course, increased with every reflection of light from the surface of conventional reflectors. With even the best conventional reflectors which absorb 4% of incident light, the intensity level of reflected light is about 81.5% after only five reflections.
These absorptive losses are also substantially increased when the backlight is used in combination with various light recycling films such as a structured partially reflective film. One micro-replicated structured partially reflective film is available as OPTICAL LIGHTING FILM from Minnesota Mining and Manufacturing Company, St. Paul, Minn.
Structured partially reflective films typically have excellent reflectivity over certain ranges of angles but high transmission over others. Micro-replicated structured partially reflective films are available as Brightness Enhancement Film, available from Minnesota Mining and Manufacturing Company. In general, structured partially reflective films redirect and transmit light into a relatively narrow range of angles while reflecting the remainder of the light. As a result, structured films transmit light and enhance brightness in backlight systems by recycling light which would otherwise exit a backlight outside a normal viewing angle.
Although recycling light in that manner is generally desired, it is a disadvantage when combined with conventional reflectors because a portion of the light which is reflected back into the light guide is absorbed or transmitted by the conventional back reflectors. Those increased absorption losses reduce the luminance or brightness attainable by this combination of the backlight system.
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Meaning of Symmetry
What is Symmetry:
Symmetry is called the exact correspondence that is verified in the shape, size and position of the parts of an object considered as a whole. The word comes from Latin symmetrĭa, and this in turn from the Greek συμμετρία (symmetry).
Symmetry, as such, is a concept related to different disciplines such as geometry, drawing, graphic design, architecture and the other arts. Likewise, we can find it sciences such as biology, physics, chemistry and mathematics.
Symmetry in Geometry
In Geometry, symmetry is called the exact correspondence that is recorded in the regular arrangement of the parts or points that make up a body or figure, considered in relation to a center, axis or plane. Thus, different types of symmetries are verified:
- Spherical symmetry: it is one that occurs under any type of rotation.
- Axial symmetry (also called rotational, radial or cylindrical): it is one that occurs from an axis, which means that any rotation produced from that axis does not lead to any change in position in space.
- Reflective or specular symmetry: it is defined by the existence of a single plane where one half is the reflection of the other.
- Translational or translational symmetry: it is the one that occurs in an object or figure when it is repeated at an always identical distance from the axis and along a line that can be placed in any position and that can be infinite.
Symmetry in Biology
In Biology, symmetry is called the correspondence that is recognized in the body of an animal or plant, taking as a point of reference a center, an axis or a plane, in relation to which the organs or equivalent parts are arranged in an orderly fashion. Most multicellular organisms have bodies where some form of symmetry is recognized, which, as such, can manifest itself in two ways:
- Radial symmetry: it is that presented by organisms whose bodies can be divided by two or more planes. This type of organism has similar parts arranged around a common central axis, such as sea urchins or starfish.
- Bilateral symmetry: that of organisms that can be divided into two equal halves, so that both halves form the same images, such as humans or dogs.
Symmetry and asymmetry
Asymmetry is the opposite of symmetry. As such, we can define it as the lack of correspondence or balance between the shape, size and position of the parts of a whole. Thus, asymmetry is manifested as the lack of equivalence between the features that make up the appearance of an object or figure. | https://lifestylemommy.me/simetria-U8Q |
There are so many little life skills that we, as adults, have managed to master over the years. How to put on a jacket. How to tie our shoes. How to blow a bubble with our gum and snap our fingers. (Okay, those last two might not really be “life skills,” but they’re important, nonetheless.) And yet, they’re kind of hard to teach.
“Let’s see, to whistle, you just kind of purse your lips like this and, I don’t know, sort of blow air through the opening… no, more slowly than that… purse your lips a little more, maybe… eh, you’ll figure it out at some point,” we say.
One such life skill we can’t wait around for them to figure out on their own, though, is how to blow their noses. Because snotty noses are gross and we are not interested in wiping them forever.
This tip comes from Today’s Parent and was part of a 30-part slideshow full of back-to-school hacks. But really, this one is an all-year-round hack: Teach them with a cotton ball.
1. Familiarize her with the idea of blowing air out of her nose by getting her to move a cotton ball with only nose air (keeping her mouth closed).
2. Now she’s ready to try with a tissue. Have her gently press one nostril closed while she blows with the other, then switch sides.
3. Have her dispose of her tissue once she’s done and wash her hands to prevent the spread of germs.
If you don’t have cotton balls handy, you could also try putting a clean tissue on a table and have them practice blowing out of their nose to move the tissue. Hell, make a game out of it by racing to see who can blow the tissue across the table the fastest.
Once they’re proficient at that, you can get back to teaching them how to whistle.
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ENTERTAINMENT
California twins born in different years. LOL
Aylin Trujillo, a healthy baby girl from Greenfield, weighing 5 pounds and 14 ounces, was the first baby born in the new year in Monterey County.
Aylin arrived 15 minutes after her brother Alfredo, who was born on Dec. 31 at 11:45 p.m., weighing 6 pounds and 1 ounce.
Their birth is special because they were born on different days, months and years.
Twins with different birthdays are rare, and some estimate the chance of twins being born in different years as one in 2 million.
The twins were born at Natividad Hospital in Salinas.
HEALTH
4 reasons why a pregnant woman should make love regularly
Now that you’re pregnant, has your sex life gone into a deep freeze? If so, consider thawing it out.
In most cases, not only is a roll in the hay perfectly safe through your final trimester, it’s good for your mental health and your relationship. Here, our top four reasons to get down while you’re knocked up.
1. Pregnant sex will bolster your bond.
Many women become intensely focused on their pregnancies, which can make their partners feel left out, says Pepper Schwartz, Ph.D., professor of sociology at the University of Washington in Seattle. “It’s important to share physical affection as a way of sustaining what is, after all, the core building block of your new family,” Schwartz says.
2. You’ll discover new sex positions.
The missionary position goes out the window pretty quickly (man-on-top puts too much pressure on your belly). Try sitting at the edge of your bed while your partner kneels or stands and enters you from the front, or the spoon position, with both of you lying on your sides as he enters you from behind.
3. Pregnant sex feels different — and sometimes even better.
Pregnancy increases blood flow to your pubic area, which heightens sensitivity, so some women experience enhanced orgasms, says Claire Jones, M.D., an OB-GYN at Mount Sinai Hospital in Toronto. Your vagina is also more lubricated because of your increased estrogen, and your breasts can be more sensitive.
4. Orgasms are a natural stress reliever.
Orgasms flood your body with oxytocin, a hormone that produces endorphins, which leave you feeling calm and happy. When you find yourself stressed out consider that sex releases endorphins that can make you feel more secure and even alleviate pain, Schwartz says.
HEALTH
7 Steps to get pregnant with blocked fallopian tubes
There are 7 steps that could allow you get pregnant even with a blocked fallopian tube. It’s not time to give up on your quest to have your baby. Even you too could carry your bundle of joy in a matter of months.
What Causes Blocked Fallopian Tubes?
Blockages can occur in the Fallopian tubes for a number of reasons, but the most common cause is pelvic inflammatory disease (PID).
Typically the result of a sexually transmitted disease, PID is a bacterial infection of the reproductive organs that affects the uterus and Fallopian tubes. The infection may lead to pelvic pain, abscess growth, scarring from adhesions, and may even cause an ectopic pregnancy if left untreated.
Additional causes of blocked Fallopian tubes include an ongoing or past experience of…
- Uterine infections
- STD infections
- Miscarriages
- Abdominal or pelvic surgeries
- Endometriosis
Step 1 – Understand why fallopian tubes are so important in getting pregnant
In natural unassisted conception, the fallopian tubes are a vital part of achieving pregnancy. The finger-like projections at the end of the tube “collect” the egg which is ovulated from the adjacent ovary. To do this, fallopian tubes must be freely movable, not stuck to the pelvic wall, uterus or ovaries by adhesions.
Once the egg is collected, the tube safeguards the egg until it is fertilised by sperm, where after it nurtures the resulting embryo as it moves through the length of the tube to the uterus over five days. To function as an incubator where the egg and sperm meet and the initial stages of embryo development takes place, the tubes must be open (patent). In addition, the inside lining of the fallopian tubes must act as a conveyor system, moving the developing embryo to the uterus where it implants 3 to 5 days after ovulation.
If your fallopian tubes are damaged or blocked (called tubal factor infertility) the egg and the sperm are prevented from interacting, and the proper movement of embryos along the tube to the uterus is obstructed, preventing a pregnancy.
Step 2 – Understand how fallopian tubes can be damaged or blocked
The fallopian tubes are delicate structures, as thin as the lead of a pencil. For this reason, they can easily become blocked or damaged, which is called tubal infertility and reduces the chances of the sperm reaching the egg, proper embryo development and implantation in the uterus.
Blockages may be due to scarring from infection or previous abdominal or pelvic surgery especially when the fallopian tubes or ovaries were involved. The competence of the surgeon is crucial in limiting post-operative damage.
The main cause of tubal infertility, however, is pelvic inflammatory disease (PID), which is also associated with an increased risk of subsequent ectopic pregnancy (when the fertilised egg implants in the fallopian tube instead of the uterus).
Also known as one of the causes of fallopian tube damage is the use of the intra-uterine contraceptive device (contraceptive “loop”), especially when there is more than one sexual partner. Other possible causes include endometriosis and sexually transmittable disease such as gonorrhoea resulting in infection of the fallopian tubes.
Step 3 – Contact a specialist fertility clinic
Given how crucially important your fallopian tubes are in falling pregnant, and how very delicate and easily damaged they are, it is clear that falling pregnant with damaged or blocked fallopian tubes will require the help of specialists.
Step 4 – Attend your initial consultation
At the initial consultation, let the IVF specialists table your options and start to plan your journey to parenthood.
During the 30 – 60 minute initial consultation, highly qualified and experienced fertility specialists should:
* do an extensive review of your medical history
* perform a comprehensive infertility physical exam and blood tests
* provide in-depth explanations and answers to all your questions
* detail the treatment options
* develop with you a personalised fertility treatment plan.
Step 5 – Determine if – and to what extent – your fallopian tubes are damaged or blocked
A qualified fertility specialist will be able to determine if your fallopian tubes are blocked or damaged, using a pelvic x-ray called a hysterosalpingogram (HSG). The test involves the injection of dye into the uterine cavity and a simultaneous x-ray of the uterus and tubes, allowing the specialist to see any damage or blockage.
It may be that the flexibility of the fallopian tube is reduced, so it can’t pick up the egg when it is released from the ovary. There may be a total blockage preventing the sperm and egg to meet and produce an embryo. It could also be that there is damage to the inside wall of the fallopian tube, which prevents the embryo from moving down to the uterus. This could result in an ectopic pregnancy, where the embryo attaches to the side wall of the fallopian tube, resulting in rupturing of the tube at about seven weeks pregnancy duration.
The position and severity of the damage or blockage will determine which treatment is right for you.
Step 6 – Choose your treatment
If it has been established that your Fallopian tubes are blocked or damaged, are two options for treatment to enable your pregnancy: tubal surgery and IVF treatment.
Get a fertility clinic that offers both advanced microsurgical treatments as well as in vitro fertilisation as therapy for tubal factor infertility.
Tubal Surgery
Depending on the position of the damage or blockage – and the severity of the damage – it may be possible to repair a fallopian tube. Fortunately, there is an alternative to “open surgery”: minimally invasive surgery or laparoscopy.
Minimally invasive surgery or laparoscopy involves looking directly into your abdomen and pelvis using a small camera that is placed through an incision in your umbilicus. This allows a specialist to evaluate and potentially treat gynaecological problems such as scar tissue, adhesions and endometriosis.
For this operation you will require a general anaesthetic (you will be asleep), but in most cases you will go home the same day. After the incision is made (usually next to the navel), the laparoscope is inserted into the abdominal cavity. Either carbon dioxide or nitrous oxide gas is then passed into the cavity to separate the abdominal wall from the underlying organs. This makes examination of the internal organs easier. Anywhere between one and three more incisions are made to allow access to other surgical instruments, for example, a laser. Once a diagnosis is made or the problem is removed (or both), the instruments are taken out, the gas allowed to escape and the incisions sewn shut. The stitches may need to be removed at a later stage or else they will dissolve by themselves.
What to Expect After Surgery
Most women experience bloating, abdominal discomfort and/or back and shoulder tip pain for 24-48 hours after surgery. This is normal and is related to the gas used to distend your abdomen during the surgery. This pain should not be severe and should gradually improve over 24-48 hours. You may also feel abdominal bloating, nausea, abdominal cramps, or constipation.
Most patients are able to resume normal activities within a few days to one week. We recommend that you do not engage in any strenuous physical activity for about a week or so. Following a pelvic laparoscopy, we recommend you use sanitary towels instead of tampons to cope with any vaginal bleeding or discharge.
It is absolutely essential that only a competent qualified fertility specialist perform this advanced surgery.
If surgery is not feasible because of extensive damage to your Fallopian tubes, In Vitro-Fertilisation is another option.
In Vitro Fertilisation (IVF) Treatment
In vitro fertilisation (IVF) treatment was originally developed for women with damaged or missing Fallopian tubes in 1983, and since then more than 5 million babies have been born worldwide as a result of IVF treatment, with success rates comparable – and even superior – to those of nature.
In the simplest terms, IVF treatment is a process of assisted reproduction where the egg and sperm are fertilised outside of the body to form an embryo, which is then transferred to the uterus to hopefully implant and become a pregnancy.
However, IVF treatment is not a single event, but rather a series of procedures that are completed over five stages to complete a treatment cycle.
IVF treatments commence with a course of hormone therapy to stimulate the development of several follicles in the ovary. Under ultrasound guidance, these are then punctured with a specialised needle to retrieve eggs, which are then fertilised in a petri dish (‘in vitro’ which literally means ‘in glass’) to create several embryos. After three to five days in an incubator, one or two of these embryos are transferred through the vagina to the uterus, where implantation occurs and pregnancy begins. The whole process from commencement of ovarian stimulation up to the embryo transfer stage usually takes just under three weeks.
Step 7 – Complete your treatment
Whether surgery or IVF treatment is the right option for you,ensure that you get state-of-the-art fertility treatment, in a caring and comfortable environment
Your next step
You have already completed the first two Steps to getting pregnant with blocked fallopian tubes: understanding why your fallopian tubes are so important to getting pregnant and how they can become damaged or blocked.
HOW TO
How to Teach Your Kid to Blow His Nose
A kid as young as 2 can learn how. Your child is probably already pretty good at blowing air out of his mouth (thanks, bubble wands and birthday candles!), and he can use the same concept to clear his nostrils.
To practice, gently place a finger over your child’s lips to show him that he can make air come out of his nose, says Katherine O’Connor, M.D., a mom of three and a pediatrician at the Children’s Hospital at Montefiore, in New York City. You can also teach him to blow bubbles underwater during a bath and then have him apply the same technique when his nose feels stuffed up.
But if your kid learns best through play, challenge him to this fun race: Have him move a cotton ball, a feather, or a little ball of tissue paper across a flat surface as fast as possible—using only his nose! (Just be prepared for sprays of snot, and wipe down the surface afterward.)
When it’s time for tissues, place one over your child’s nose and press down on his left nostril while he blows out of his right. Repeat with the other nostril, then let him do it. It’s always helpful to demonstrate it yourself. “Young kids love to imitate, so they are more likely to try to use tissues on their own if they see you using them first,” says Rebecca G. Carter, M.D., a mom of two and a pediatrician at the University of Maryland Children’s Hospital, in Baltimore. You can also show him by using tissues and pretend sneezing into your arm during playtime.
To make sure that germy tissues get disposed of properly, take advantage of your kid’s eagerness to be helpful by giving him the “garbage collector” job for a few minutes daily. “Even if he misses the pail when he tosses a wrapper or a used napkin, it’ll show him that he can help you in small ways around the house,” says Dr. Carter, who successfully used this strategy with both her kids. When your child does get sick, throwing out his used tissues will be a natural extension of what he already knows how to do. | https://antvt.com/how-to-teach-your-kid-to-blow-their-nose/ |
Beneath Dixie State University lies an intricate system of tunnels that connect to most major buildings on campus.
The tunnels were first approved in 1975, director of facility operations and energy, Bruce Peacock, said. Since that time, DSU has added to the tunnels every time a new building was constructed.
The first phase when creating a new building on campus is to dig down and connect a new part of the tunnel system. Once the tunnel has been constructed, the actual infrastructure is built. This takes a month or two to complete, but once it’s finished the new building is connected to the other main structures on campus, making work easier and cheaper to complete for years to come.
The tunnels run at about 6.5 feet high and 6 feet wide in most places. In all, there are approximately 1.5 miles of tunnel underneath campus.
They were originally built in the shape of a “U,” with small passages running from the main shaft, but the plan is to eventually make it a complete loop that gives staff members access to the entire campus.
Peacock said the tunnels are also some of the cleanest and most well-maintained tunnels that exist in the country. Jeff Hunt, an electrician at the heating plant, said he has worked in tunnels all over the state of Utah, and DSU’s are by far the cleanest he’s seen.
Walking through the tunnels makes it clear they are well cared for. With adequate lighting and well-organized and clearly labeled pipes, the tunnels were a pleasant place to spend an afternoon (although without a guide it would have been almost impossible to find a way out).
Hunt said the tunnels have five uses: cooling, heating, high speed internet, phone system and electrical. The main use is to run hot and cold water through the entire campus. The only people with access to the tunnels are groundskeepers and electricians, and they mostly use them for maintenance purposes. However, Kerry Dillenbeck, a HVAC specialist for the heating plant, said they often use the tunnels in the winter to get from building to building without having to walk through the cold.
Peacock said the tunnels are used almost every day, giving mechanical staff the ability to get around campus, but also allowing them to have constant eyes and ears on the mechanics inside the tunnel.
“Our preventative maintenance department will go through all of campus quarterly, through every piece of equipment on campus and check it out,” Peacock said.
An important function of the tunnels is to provide heating and air conditioning to almost every building on campus. Because the school uses the tunnels to heat and cool the buildings, the school saves thousands of dollars every year. Peacock said the school has been lucky to have the tunnels because it adds a maintenance component and a convenience component.
They also contain network connections for energy and utility metering, as well as back door entrance to maintenance rooms in various buildings on campus, making it easy for staff to get into those rooms when needed.
The tunnels are an intricate and important part of the campus, and the university relays heavily on them. While the idea of trying to find and explore this underground maze may seem like an interesting idea, it’s best not to risk interrupting the staff and risk endangering yourself for the sake of an Instagram photo. | https://dixiesunnews.com/news/articles/2018/02/04/exploring-dsus-hidden-tunnels/ |
In cooperation with the Bureau of Mineral and Petroleum (BMP), Government of Greenland, the Geological Survey of Denmark and Greenland (GEUS) hereby invites tenders for the provision of airborne magnetic surveying in Greenland related to project AEROMAG 2012 & 2013. This is a joint project by BMP and GEUS. GEUS will manage the project.
Later, potential bidders questions and answers to the tender material can also be downloaded from the present page http://www.geus.dk/cgi-bin/webbasen_nyt.pl?id=1329232610|cgifunction=form.
Starting in 1992, many regional aeromagnetic surveys have been acquired over selected areas in Greenland. The primary objective has been and still is to stimulate mining exploration activity in Greenland. A secondary objective is to provide modern geophysical data of high quality that will have a lasting value in the understanding of the geology of Greenland. Such data are prerequisite for successful mineral exploration. This new project in South East Greenland in 2012 and 2013 confirms the stated commitment of the Greenland Government to encourage mining exploration activities. Throughout these projects, GEUS has been the operator handling project management, quality control, compilation, and the maintenance of the data for future use in both the public and the private domain. Thus, the acquired data will become part of the national geoscientific database for Greenland, and will become available for purchase to e.g. the exploration industry.
The first surveys in 1992 2001 covered South Greenland, Southwest Greenland, the Disko Bugt, region both onshore and offshore, central West Greenland, and the region around Uummannaq on the West Coast. In 2011 and 2012, the plan is to cover selected parts of the South East Greenland region, as an integral component of a mineral resource assessment programme of that region, taking place from 2009 to 2015.
The project is part of a major effort to improve the knowledge of South East Greenland through a mineral resource assessment program (MRAPSEG); geochemical surveys were carried out in 2009 and 2010, together with geological reconnaissance surveying. In 2011, a major programme of geological fieldwork was carried out in the southern target area and will be followed by further fieldwork in the same area in 2012. The aeromagnetic survey will start in 2012. The subsequent aeromagnetic survey in 2013 will focus on the region around Tasilaq further to the north, where geological fieldwork is expected to take place in 2013 and maybe 2014. As in previous airborne geophysical surveys in Greenland, the data will be released to the public the following year, probably around March; i.e. the data from the 2012 survey will be ready for public presentation by March 2013.
Further information can be found at the GEUS web-site www.geus.dk, See www.geus.dk/departments/economic-geol/AGS/AGS-intro-dk.htm (airborne geophysical programme) and www.geus.dk/cgi-bin/webbasen_nyt.pl?id=1314249921|cgifunction=form (activities in SE Greenland). | http://www.geus.dk/om-geus/nyheder/nyhedsarkiv/2012/feb/tender-for-airborne-magnetic-survey-in-southeast-greenland-1/ |
Oftentimes, differences in opinion will arise between you and the school about what is best for your child. Luckily, parents always have “procedural rights”—the right to disagree with a school district’s decisions regarding their child’s education or well-being. To do so, you must go through certain channels which can include mediation, due process hearings or independent evaluations of your child.
No matter where you are in the IEP or 504 Plan process, you can exercise your procedural rights. When a parent does so and files a complaint, the school may request something called a “resolution” meeting. Resolution meetings are informal gatherings with the parent and a school official who can make important decisions regarding your child’s education, such as the Director of Special Education. There, you will try to resolve any relevant disagreements without involving any formal procedures.
However, a parent is allowed to choose “mediation” instead of a resolution meeting. If both parties agree, a state mediation session will be held in an effort to resolve the conflict before a due process hearing is necessary. The main difference between mediation and a due process hearing is that mediation is less formal and will not include an an Administrative Law Judge.
You may want to request mediation if: • You request that your child be evaluated for special education services, and the school denies your request;
• The school wants to change the services your child receives through their IEP or 504 Plan and you disagree with the change; or
• You believe your child needs additional services and the school district refuses to provide these services.
Once you request mediation, the school cannot change your child’s special education classification, placement, or services until the issue is resolved—this is called the “stay put” effect, and you should specifically request it in your written complaint if you wish to take advantage of it.
In the mediation session, you will be placed with two mediators from the New Jersey State Department of Education’s Office of Special Education Programs (OSEP). These mediators will be trained and impartial, and they cannot issue a decision like a Judge can. Instead, they seek to help parties come to an agreement by helping them define the issues and work through their conflict.
If mediation is successful and you reach an agreement, the mediator will write up the decision for both parties to sign. If this occurs, both parties must comply with the terms of the signed agreement. However, if mediation is unsuccessful, the mediator can request a due process hearing.
If you do not want to have a mediation session, as a parent, you can refuse to participate. If you still wish to move forward with your complaint, you or the school must file a request for a due process hearing. Before requesting mediation or a due process hearing, you may want to obtain legal advice. Susan Clark Law Group can help you navigate the mediation process and advocate for your child.
Contact us at the Susan Clark Law Group at 732-637-5248 for a free consultation. | https://susanclarklawgroup.com/mediation-nj-law-firm.html |
1. Is it commercializable?
Look at the cost of your invention, competitors’ products, the invention’s ease of use, and consumer demand.
2. Did I invent it?
You can only obtain a patent if you personally
invented something. The inventor is the initial patent rights owner.
You may also be a co-inventor to file. A co-inventor is someone who contributed to at least one novel and non-obvious concept that makes the invention patentable. This will be further discussed later.
3. Do I own it?
You must own the invention to file a patent application. This may not be the case if your employer owns the rights to the invention, i.e. you’ve given up rights to the invention prior to its creation, you were hired specifically to invent it, or your employer has certain rights to use the invention.
4. Is it
useful?
A patent is only granted for useful
inventions. Though most inventions are useful, the USPTO has found the
following to be ineligible for patents:
- ornamental, without utility. You may want to
consider a design patent application if your invention has visual ornamental
characteristics embodied in or applied to an article of manufacture that is not
functionally useful;
- unsafe drugs;
- nuclear weapons;
- immoral inventions;
- non-operable inventions;
- inventions only with illegal uses; and
- theoretical phenomenon.
5. Does it fit into a patent “class”?
The U.S. Supreme Court said that anything man-made falls into these “classes,” but anything natural or abstract will not. The “classes” are broad, so an invention is likely to fit into one of these categories. In fact, it might fit into a couple. Ultimately, for a patent to issue, an invention must fall into at least one of them. The following are the five “classes.” What are these fives classes?
6. Is it novel?
Patented inventions must be different from existing knowledge or previous inventions, otherwise known as prior art. That means the new invention should be physically or operationally unique in at least one way from the date it was conceived, otherwise known as the date of invention or the date you filed a patent application. Novelty includes the invention incorporating a new feature, using an old feature in a new way, or having a new combination of old features. How to know if your invention is novel?
7. Is it non-obvious?
This is the highest bar to patent
ownership. If something is obvious, then
it isn’t patentable. If it is surprising
and unexpected, then it usually is non-obvious and hence, may be patentable.
Factors in determining obviousness include:
- invention has commercial success;
- invention solves a non-obvious problem;
- invention subtracts a piece of hardware that was
included in the prior art;
- invention modifies the prior art in a new way;
- industry needs the invention;
- others have tried to come up with this invention
but failed;
- other inventors said this invention was
impossible;
- others have copied this invention; or
- others in the field have praised the invention.
You can read more about the USPTO’s process for determining obviousness at http://www.uspto.gov/web/offices/pac/mpep/documents/2100_2141.htm.
Briefly, the focus for the USPTO when making a
determination of obviousness is—what a person of ordinary skill in the
pertinent art would have known at the time of the invention, and on what such a
person would have reasonably expected to have been able to do in light of that
knowledge. This is the standard regardless of whether the source of that knowledge
and ability was documented prior art, general knowledge in the art or common
sense. | https://www.inventiv.org/patent-guide/ask-yourself-these-7-questions-to-determine-whether-you-should-get-a-patent/ |
Every child participating in Countdown to Kindergarten will receive a green T-shirt, which will serve as a ticket to get into various fun events over the summer.
Fayette County Public Schools is kicking off a summer full of free or low-cost activities to help prepare incoming kindergarten students for their first day of school.
"Countdown to Kindergarten," unveiled at a news conference Tuesday, will offer a bit of everything: plays children can perform themselves, ballet performances, museum visits, hands-on arts projects and hints of what kindergarten will be like.
All are designed to provide fun and promote the importance of early childhood learning.
The summer events are scheduled to wrap up with a "Going To School" rally Aug. 2 at the Lexington Legends' Whitaker Bank Ballpark, and Aug. 6 at an all-day swim at the Southland, Tates Creek, Woodland and Castlewood pools. Lexington schools open Aug. 11. | https://www.kentucky.com/news/local/education/article44097546.html |
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zero-G
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Bedeutung von "zero-G" im Wörterbuch Englisch
WÖRTERBUCH
AUSSPRACHE VON
ZERO-G
AUF ENGLISCH
zero-G
[ˌzɪərəʊˈdʒiː]
GRAMMATIKALISCHE KATEGORIE VON
ZERO-G
Substantiv
Adjektiv
Verb
Adverb
Pronomen
Präposition
Konjunktion
Determinante
Ausruf
Zero-G
ist ein
Substantiv
.
Das
Nomen
oder
Substantiv
ist die Art Wort, dessen Bedeutung die Wirklichkeit bestimmt. Substantive benennen alle Dinge: Personen, Objekte, Empfindungen, Gefühle usw.
WAS BEDEUTET
ZERO-G
AUF ENGLISCH
Hier klicken,
um die ursprüngliche Definition von «zero-G» auf Englisch zu sehen
.
Hier klicken,
um die automatische Übersetzung der Definition auf Deutsch zu sehen
.
Schwerelosigkeit
Weightlessness
"Schwerelosigkeit" oder Abwesenheit von "Gewicht" ist in der Tat ein Fehlen von Stress und Belastung, die sich aus außen angelegten Kräften ergibt, typischerweise normale Kräfte von Böden, Sitzen, Betten, Schuppen und dergleichen. Gegenüberdessen verursacht ein einheitliches Gravitationsfeld selbst keine Belastung oder Belastung, und ein Körper im freien Fall in solch einer Umgebung erlebt keine G-Kraft-Beschleunigung und fühlt sich schwerelos an. Dies wird auch als "Null-g" bezeichnet. Wenn Körper von nicht-gravitativen Kräften beauftragt werden, wie in einer Zentrifuge, einer rotierenden Raumstation oder innerhalb eines Raumschiffs mit Raketenfeuerung, wird ein Gefühl des Gewichts erzeugt, da die Kräfte die Trägheit des Körpers überwinden. In solchen Fällen kann ein Gefühl des Gewichts, im Sinne eines Spannungszustandes auftreten, auch wenn das Gravitationsfeld null ist. In solchen Fällen sind G-Kräfte gefühlt, und Körper sind nicht schwerelos. Wenn das Gravitationsfeld ungleichförmig ist, erleidet ein Körper im freien Fall Gezeiteneffekte und ist nicht stressfrei. In der Nähe eines Schwarzen Lochs können solche Gezeiteneffekte sehr stark sein. Im Falle der Erde sind die Effekte gering, vor allem bei Objekten von relativ geringer Dimension und die Gesamtempfindung der Schwerelosigkeit in diesen Fällen bleibt erhalten.
'Weightlessness', or an absence of 'weight', is in fact an absence of stress and strain resulting from externally applied forces, typically normal forces from floors, seats, beds, scales, and the like. Counterintuitively, a uniform gravitational field does not by itself cause stress or strain, and a body in free fall in such an environment experiences no g-force acceleration and feels weightless. This is also termed 'zero-g.' When bodies are acted upon by non-gravitational forces, as in a centrifuge, a rotating space station, or within a space ship with rockets firing, a sensation of weight is produced, as the forces overcome the body's inertia. In such cases, a sensation of weight, in the sense of a state of stress can occur, even if the gravitational field was zero. In such cases, g-forces are felt, and bodies are not weightless. When the gravitational field is non-uniform, a body in free fall suffers tidal effects and is not stress-free. Near a black hole, such tidal effects can be very strong. In the case of the Earth, the effects are minor, especially on objects of relatively small dimension and the overall sensation of weightlessness in these cases is preserved.
Mehr lesen
Hier klicken,
um die ursprüngliche Definition von «zero-G» auf Englisch zu sehen
.
Hier klicken,
um die automatische Übersetzung der Definition auf Deutsch zu sehen
.
WÖRTER AUF ENGLISCH, DIE REIMEN WIE
ZERO-G
agee
əˈdʒiː
ajee
əˈdʒiː
bargee
bɑːˈdʒiː
dirige
ˈdɪrɪˌdʒiː
dischargee
ˌdɪstʃɑːˈdʒiː
Fiji
ˈfiːdʒiː
galiongee
ˌɡæljənˈdʒiː
gee
dʒiː
jaygee
ˌdʒeɪˈdʒiː
koji
ˈkəʊdʒiː
Meiji
ˈmeɪˈdʒiː
mergee
mɜːˈdʒiː
mortgagee
ˌmɔːɡɪˈdʒiː
obligee
ˌɒblɪˈdʒiː
pongee
pɒnˈdʒiː
refugee
ˌrɛfjʊˈdʒiː
salvagee
ˌsælvɪˈdʒiː
SPG
ˌespiːˈdʒiː
T&G
ˌtiːənˈdʒiː
USCG
ˌjuːessiːˈdʒiː
WÖRTER AUF ENGLISCH, DIE ANFANGEN WIE
ZERO-G
zero
growth
zero
hour
zero
in
zero
option
zero
point
zero
population growth
zero
stage
zero
tolerance
zero-
base
zero-
based
zero-
coupon bond
zero-
emission
zero-
rate
zero-
rated
zero-
rating
zero-
sum
zero-
sum game
zero-
zero option
zero
th
zero
th law of thermodynamics
WÖRTER AUF ENGLISCH, DIE BEENDEN WIE
ZERO-G
Super
-G
Synonyme und Antonyme von zero-G auf Englisch im Synonymwörterbuch
SYNONYME
MIT
«ZERO-G»
VERWANDTE WÖRTER IM WÖRTERBUCH ENGLISCH
zero-G
zero
beyblade
wiki
plane
registry
eyewear
vocaloid
physical
therapy
frames
weightlessness
absence
weight
fact
stress
strain
resulting
from
externally
applied
forces
typically
normal
floors
seats
beds
scales
corporation
float
astronaut
superhero
experience
only
kind
once
lifetime
opportunity
digital
audio
samples
soundware
download
shop
enter
style
balance
comfort
welcome
titanium
home
news
company
optical
collection
retail
media
contact
menu
discover
define
create
work
giaf_large_hp_home
g_abbey_theatre_large_hp_home
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_slide_home
g_camden_large_home
sector
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smith
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spark
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sweet
protection
troy
designs
union
binding
voile
flight
parabolic
flights
airzerog
board
have
ever
dreamt
flying
forgetting
laws
gravity
floating
adventures
amazing
true
specially
modified
Übersetzung von zero-G auf 25 Sprachen
ÜBERSETZER
ÜBERSETZUNG VON
ZERO-G
Erfahre, wie die Übersetzung von
zero-G
auf
25 Sprachen
mit unserem mehrsprachigen
Übersetzer Englisch
lautet.
Die
Übersetzungen von zero-G
auf andere Sprachen, die in diesem Bereich vorgestellt werden, sind zustande gekommen durch
automatische statistische Übersetzung
, wobei die Basiseinheit der Übersetzung das Wort «zero-G» in Englisch ist.
zh
Übersetzer Deutsch -
Chinesisch
零重力
1.325 Millionen Sprecher
es
Übersetzer Deutsch -
Spanisch
cero -G
570 Millionen Sprecher
en
Englisch
zero-G
510 Millionen Sprecher
hi
Übersetzer Deutsch -
Hindi
शून्य जी
380 Millionen Sprecher
ar
Übersetzer Deutsch -
Arabisch
صفر -G
280 Millionen Sprecher
ru
Übersetzer Deutsch -
Russisch
Zero-G
278 Millionen Sprecher
pt
Übersetzer Deutsch -
Portugiesisch
zero L
270 Millionen Sprecher
bn
Übersetzer Deutsch -
Bengalisch
জিরো-জি
260 Millionen Sprecher
fr
Übersetzer Deutsch -
Französisch
zéro - G
220 Millionen Sprecher
ms
Übersetzer Deutsch -
Malaysisch
Sifar-G
190 Millionen Sprecher
de
Übersetzer Deutsch -
Deutsch
Zero-G
180 Millionen Sprecher
ja
Übersetzer Deutsch -
Japanisch
ゼロ-G
130 Millionen Sprecher
ko
Übersetzer Deutsch -
Koreanisch
제로 -G
85 Millionen Sprecher
jv
Übersetzer Deutsch -
Javanisch
Nol-G
85 Millionen Sprecher
vi
Übersetzer Deutsch -
Vietnamesisch
zero- G
80 Millionen Sprecher
ta
Übersetzer Deutsch -
Tamil
பூஜ்யம் ஜி
75 Millionen Sprecher
mr
Übersetzer Deutsch -
Marathi
शून्य-जी
75 Millionen Sprecher
tr
Übersetzer Deutsch -
Türkisch
sıfır G
70 Millionen Sprecher
it
Übersetzer Deutsch -
Italienisch
zero G
65 Millionen Sprecher
pl
Übersetzer Deutsch -
Polnisch
nieważkości
50 Millionen Sprecher
uk
Übersetzer Deutsch -
Ukrainisch
Zero -G
40 Millionen Sprecher
ro
Übersetzer Deutsch -
Rumänisch
de zero -G
30 Millionen Sprecher
el
Übersetzer Deutsch -
Griechisch
μηδέν - G
15 Millionen Sprecher
af
Übersetzer Deutsch -
Afrikaans
nul -G
14 Millionen Sprecher
sv
Übersetzer Deutsch -
Schwedisch
noll -G
10 Millionen Sprecher
no
Übersetzer Deutsch -
Norwegisch
null -G
5 Millionen Sprecher
Tendenzen beim Gebrauch von zero-G
TENDENZEN
TENDENZEN BEIM GEBRAUCH DES BEGRIFFES
«ZERO-G»
Der Begriff «zero-G» wird für gewöhnlich gebraucht und belegt den Platz
60.450
auf unserer Liste der meistgebrauchten Begriffe des
Wörterbuch auf Englisch
.
0
100%
HÄUFIGKEIT
Für gewöhnlich gebraucht
72
/100
Auf der vorherigen Grafik wird die Häufigkeit der Nutzung des Begriffs «zero-G» in den verschiedenen Ländern angezeigt.
Wichtigste Tendenzen bei der Suche und dem allgemeinen Gebrauch von
zero-G
1
zero g beyblade
2
zero g wiki
3
zero g plane
4
zero g registry
5
zero-G definition
6
zero g eyewear
7
zero g vocaloid
8
dictionary zero-G
9
zero g physical therapy
10
zero g frames
Liste der wichtigsten Suchen, die von den Nutzern bei dem Zugang zu unserem
Wörterbuch Englisch
durchgeführt wurden und die meistgebrauchten Ausdrücke mit dem Wort «zero-G».
HÄUFIGKEIT DER BENUTZUNG DES BEGRIFFS
«ZERO-G»
IM VERLAUF DER ZEIT
Die Grafik druckt die
jährlich Entwicklung der Nutzungshäufigkeit
des Worts «zero-G» in den letzten 500 Jahren aus. Seine Implementierung basiert auf der Analyse der Häufigkeit des Auftretens des Begriffs «zero-G» in den digitalisierten gedruckten Quellen auf Englisch seit dem Jahr 1500 bis heute.
Zitate, Bibliographie und Aktuelles übe zero-G auf Englisch
BEISPIELE
10 BÜCHER, DIE MIT
«ZERO-G»
IM ZUSAMMENHANG STEHEN
Entdecke den Gebrauch von
zero-G
in der folgenden bibliographischen Auswahl. Bücher, die mit
zero-G
im Zusammenhang stehen und kurze Auszüge derselben, um seinen Gebrauch in der Literatur kontextbezogen darzustellen.
1
Zero
---
G
Poised to make history, SpaceVentures, Inc., hovers on the brink of launching the first commercial space flight.
Alton L. Gansky,
2010
2
Club
Zero
-
G
Douglas Rushkoff, author of eight books on media and culture, as well as the novels Ecstasy Club and Exit Strategy, marks his graphic novel debut with Club Zero-G. Teaming with Canadian independent comic artist Steph Dumais, Rushkoff has ...
Douglas Rushkoff,
2004
3
I Hate
Zero
-
G
And this is not the end. The ultimate thrill of the story begins when, at the age of 36, John releases its latest invention, which needs to be done on Free Fall station.
Douglas A. Owen,
2012
4
Sex and Violence in
Zero
-
G
: The Complete Near Space Stories, ...
All the stories of Allen Steele's award-winning "Near Space" series--now in an expanded and revised second edition!
Allen Steele,
2012
5
I Hate
Zero
-
G
Your other clothes could attract the odor from the ones infused with the scent of vomit. It is a never ending problem when it comes to
zero-g
travel. “Not everyone likes
zero-g
but it will be an adventure to see Free Fall. How many people actually ...
Douglas Owen
6
Computer Mathematics: Proceedings of the Fifth Asian ...
Uri=1d-zero(Fi/qi), then (7?!,- .. ,7jn) € Llj=1d-zero(Gj/hj), that is to say, Vfai, . ..,!?n )€ £"(U[=1d-zero(Fi/gi) -> U*=1d-
zero(G
,//i,)). We consider firstly the inclusion of two differential quasi-algebraic sets. Theorem 1. Let F, G be two finite non-empty ...
2001
7
The
Zero
-
G
Headache
When Zero-G, a hot new space-rock boy band, arrives at the space station, the AstroKids learn a valuable lesson about hospitality.
Robert Elmer,
2000
8
Space: Surviving In
Zero
-
g
Discusses the spacewalk performed by astronauts Linda Godwin and Dan Tani in 2001 to repair the motors on the solar wings of the International Space Station, along with facts about what makes space dangerous.
Donna Latham,
2005
9
Zero
G
Mysteries and the Weightlessness Attraction
Everything about exploring weightlessness/zero gravity and the amusement attractions, excluding gaming and adult contents, will be studied. Check the book's companion website www.0GSuite.com (0 is the number zero) for more information.
Jets Hunt,
2010
10
Pulling
G
: Human Responses to High and Low Gravity
Pulling G provides an overview of G-related research and the development of intervention methods to mitigate the effects of increased and reduced G. As well as relating the training required to overcome G-forces on the Formula 1 track, Erik ...
Erik Seedhouse,
2012
10 NACHRICHTEN, IN DENEN DER BEGRIFF
«ZERO-G»
VORKOMMT
Erfahre, worüber man in den einheimischen und internationalen Medien spricht und wie der Begriff
zero-G
im Kontext der folgenden Nachrichten gebraucht wird.
1
Ants in space grapple well with
zero-g
Ants carried to the International Space Station were still able to use teamwork to search new areas, despite falling off the walls of their containers for up to eight ...
«BBC News, Mär 15»
2
Zero-G
flying means high stress for an old A310
“
Zero-G
”, an Airbus A310 that previously served the German air force VIP fleet as “Konrad Adenauer” (registration 10+21, now F-WNOV), is one of just a handful ...
«Flightglobal, Mär 15»
3
Zero-G
Cocktail Glass Lets Astronauts Drink With Dignity
It relies on the habit liquids have in
zero G
(or microgravity, which is as close to zero as you're going to get on the International Space Station) of sticking together ...
«NBCNews.com, Mär 15»
4
Frozen's Olaf the Snowman Floats in
Zero-G
It's one giant leap for snowman-kind: Olaf, the goofy snowman from Disney's hit film "Frozen," is floating aboard the International Space Station, and we have the ...
«Discovery News, Dez 14»
5
Microgravity University: Testing the Future of Spaceflight in
Zero G
For the last 20 years, NASA's Reduced Gravity Office has opened up its
zero-g
planes to college students from around the country, who get the once in a lifetime ...
«Gizmodo, Nov 14»
6
Farewell, 'Mouse-tronauts': Lab Mice Dissected in
Zero-G
HUNTSVILLE, Ala. — After spending a month in microgravity, the last of the lab mice that were sent to the International Space Station aboard a SpaceX cargo ...
«NBCNews.com, Okt 14»
7
First
Zero-G
3D Printer Is On Its Way To The Space Station
On Tuesday morning, a SpaceX Dragon capsule will berth with the International Space Station. Included in its nearly 2 and a half tons of cargo is a first for the ...
«Forbes, Sep 14»
8
Sad News for
Zero-G
Sex Study: The Geckos Are Dead
Russia's troubled experiment to study how geckos, fruit flies and other organisms reproduce in weightlessness ended with a huge downer: When the Foton M-4 ...
«NBCNews.com, Sep 14»
9
Zero-G
Fire Pulses Like a Jellyfish on the Space Station
Prometheus would be so proud. As part of a NASA experiment, humans have brought fire to the International Space Station (ISS) to see what happens to flames ...
«Smithsonian, Aug 14»
10
Zero-G
flights offer that floating sensation
S3's website said its flights offered the “world's most affordable
ZeroG
experience”. Tickets are priced from €1,990 (Dh9,790) in a party zone that caters for up to ...
«The National, Aug 14»
REFERENZ
« EDUCALINGO.
Zero-G
[online] <https://educalingo.com/de/dic-en/zero-g>, Mär 2023 ». | https://educalingo.com/de/dic-en/zero-g |
China is rushing through a foreign investment law in an apparent attempt to placate Washington as negotiators try to dig the world’s two largest economic powers out of an ongoing trade war. But will it work?
The 3,000 or so delegates to China’s annual National People’s Congress (NPC) will endorse the new law on Friday. They don’t oppose legislation. That’s not how it is done here. When a vote is taken there are normally only handfuls who vote against. Some of them potentially for show, because 100% “yes” votes one after another would look ridiculous.
If there is pushback against a draft bill and amendments made, this happens well before the NPC sits, at a series of standing committee meetings behind closed doors. The process can take years. This time it took three months.
The Chinese government appears to have rushed through the investment law as an olive branch to the US amid trade war negotiations. However, many in the business community here in China see this law as a kind of sweeping set of intentions rather than a specific, enforceable set of rules. They fear it could be open to different and changing forms of interpretation.
The big-ticket items it is said to address, in terms of the concerns of foreign companies, include intellectual property theft, the requirement for international firms to partner up with a local entity, and unfair subsidies to Chinese companies. It will also address the preferential treatment in awarding contracts to Chinese companies, and forcing foreign firms to hand over their technological secrets as the price of entry to the massive Chinese market.
But this law isn’t going to help everyone.
There is a “black list” of 48 sectors that will not be open to foreign investment or, in some cases, not open without conditions or special permission. For example, there is a complete ban on investing in fishing, gene research, religious education, news media, and television broadcasting. Partial investment is allowed in oil and gas exploitation, nuclear power, airlines, airport operation, and public health, amongst others sectors. Non-renewable energy automobile production will require partnerships for a few years but then be phased out.
For industries not on the list, the principle is that foreign companies will receive the same treatment as their Chinese counterparts. | https://amaderorthoneeti.com/new/2019/03/15/267076/ |
OUCHHH is an Istanbul based independent design studio with cross-discipline expertise in graphic design, digital and motion graphics and sound design. A multidisciplinary creative hub focused on new media platforms, offering direction and art direction and also producing video mapping projections. Skilled in animation, design, illustration, 3D, 2D, interactivity, interaction and live-action -and seamlessly combining some or all of these- OUCHHH consider each project as a challenge and takes a fresh and unique approach to each other. We have partnerships in Barcelona and Munich and also collaborate with different teams nationally and internationally. In August 10th in Genius Loci Weimar which is a festival for audiovisual projection mapping, OUCHHH produced a collective projection called Under An Allias for “Fürstenhaus”, a historic landmark in the german cultural city of Weimar that is today home to the Hochschule für Musik Franz Liszt Weimar. In the projection the city’s history is told through abstract visual representations of industrial revolution passing by creation of the city and Bauhaus University and it also received the Honorary Mention in Prix Ars Electronica vfx/animation. | https://currentsnewmedia.org/artist/ouchhh/ |
Our association is a robust and diverse set of educators, researchers, medical professionals, volunteers and academics that come from all walks of life and from around the globe. Each month we choose a member to highlight their academic and professional career, and see how they are making the best of their membership in IAMSE. This month’s Featured Member is Amber Heck, PhD.
In 2013 when I first joined IAMSE, I was still a new faculty member with three years of classroom experience under my belt. Already feeling uninspired by the lack of diversity of teaching modalities and experiences our learners were being offered, I sought out professional development experiences outside of the institution. I was introduced to IAMSE by a respected colleague and I jumped at the opportunity, attending the ESME course at the 2013 Annual Conference in St. Andrews, Scotland. Through this course I was suddenly exposed to a whole new world of medical education. One in which teachers act as researchers and make decisions based on peer-reviewed literature. In which medical educators share experiences and work together toward establishing best practices. That week, I became part of a community of practice.
Opportunity begets opportunity, and through the ESME course I found the IAMSE Medical Educator Fellowship. Through my participation in the Fellowship, I was introduced to an inspiring group of educators. I am continually learning from and modeling myself after the intellectual curiosity and collaborative spirit that I appreciate in my colleagues and mentors on the Educational Scholarship Committee. By inviting me to become a member of the Committee, they showed confidence in me that has propelled me forward. As a member of this team, I am privileged to provide support and create opportunities for aspiring and accomplished medical education researchers.
What I love most about IAMSE is the collaborative environment. IAMSE members foster teamwork, encourage innovation, leverage each other’s strengths, and recognize, reward and celebrate these behaviors in others. In academia, it is imperative that we recognize that no man is an island, and one simply cannot grow to one’s full potential without the support and intervention of others. Mentorship should not be a solitary relationship between two individuals, but a dynamic network of associates. There is no such thing as too many mentors, as they each serve a unique purpose at different times in one’s life. Through the mentorship I receive here at IAMSE, I have discovered that I can combine all of my interests; a respect for the scientific method, a love for biologic mechanisms, and a passion for teaching, into a successful career in medical education.
Want to learn more about IAMSE Fellowship and Grant Opportunities? Visit our website here! | http://www.iamse.org/iamse-featured-member-amber-heck/ |
The paper is devoted to a level of competition in banking sector on the regional housing lending market. For 2015 - 2018 concentration index (Herfindahl-Hirschman index, HHI) and price competition one (variation of interest rates) were calculated for the 328 Russian commercial banks, which disclose their data. Based on comparative analysis these indices and their dynamics we made conclusions about some differences got by these two methods, gradually changing the market to be more competitive, and the fact that the level of competition among regions becomes closer. | https://research.nsu.ru/en/publications/%D0%BA%D0%BE%D0%BD%D0%BA%D1%83%D1%80%D0%B5%D0%BD%D1%86%D0%B8%D1%8F-%D0%BD%D0%B0-%D1%80%D1%8B%D0%BD%D0%BA%D0%B5-%D0%B6%D0%B8%D0%BB%D0%B8%D1%89%D0%BD%D0%BE%D0%B3%D0%BE-%D0%BA%D1%80%D0%B5%D0%B4%D0%B8%D1%82%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D1%8F-%D0%B2-%D1%80%D0%B5%D0%B3%D0%B8%D0%BE%D0%BD%D0%B0%D1%85-%D1%80%D0%BE%D1%81%D1%81%D0%B8%D0%B9%D1%81%D0%BA%D0%BE%D0%B9 |
“The Stokes Collection of Oak Ridge and the Manhattan Project Articles, Authentic Artifacts” is the lifetime collection of Lloyd and Betty Stokes, whose parents and families moved to Oak Ridge with their children on July 4, 1944, and Aug. 10, 1945, respectively. Both completed elementary and high school in Oak Ridge before graduating and attending college.
“The Stokes Collection of Oak Ridge and the Manhattan Project Articles, Authentic Artifacts” is the lifetime collection of Lloyd and Betty Stokes, whose parents and families moved to Oak Ridge with their children on July 4, 1944, and Aug. 10, 1945, respectively. Both completed elementary and high school in Oak Ridge before graduating and attending college.
Following college, Lloyd and Betty returned to the Oak Ridge “area” (Farragut) and dated. They married at the Chapel-on-the-Hill in Oak Ridge on Sept. 5, 1959, with a reception at The Guest House, also known as the “Alexander Motor Inn.”
“The Manhattan Project, Oak Ridge Artifacts were collected over 74 years — from 1944 to 2018 — while living and working in Oak Ridge and participating in the many organizational activities and additional activities associated with living, working and raising a family of four children in Oak Ridge,” according to a statement from the Stokeses to The Oak Ridger. “Several other people have donated artifacts to our extensive Manhattan Project collection.”
Lloyd Stokes worked 16 years in the Assembly Division at Y-12, 10 years in the Centrifuge Division at K-25 and for 14 years at ORNL as an environmental safety health and radiological protection officer (for 840 Division employees). He retired from the national lab’s Plant and Equipment Division on March 30, 1999, with 40 years and three months of company service.
“THIS YEAR ON June 8th and 9th, we will be displaying a large banner made from an enlarged 1945 Ed Westcott photo,” according to the Stokeses. “The banner is a panoramic view of the city of Oak Ridge from the Y-12 Water Tower … and banner designer Tom Walker of the Tennessee Museum of Aviation in Sevierville inserted photos of Manhattan Project symbols, medals and family life in the 1940s.”
That’s LIFE (magazines!)
An extensive collection of framed LIFE magazines from the 1940s will be on display — illustrating a variety of World War II scenes featuring aircraft such as planes and “bombers,” and U.S. military personnel as well as enemy soldiers, etc.
Additionally, a 68-page laminated LIFE magazine focusing on the atom, the world’s first atomic bombs, Oak Ridge and the Manhattan Project also will be on display. Famed photographer Ed Westcott of Oak Ridge, Tenn., escorted the LIFE magazine photographer on part of the photo shoot for the August 1945 publication, issued by LIFE within a dozen days after the world’s second atomic weapon was dropped on Japan during World War II.
“MY WIFE BETTY and I will be participating in the Center for Oak Ridge Oral History (or COROH) ‘Ask Me, I Was There’ project with our collection to increase visitors’ knowledge about the Manhattan Project and Oak Ridge history,” said Lloyd Stokes, crediting longtime Oak Ridge Public Library Director Kathy McNeilly with developing the “Ask Me” program concept and for seeking out his and Betty’s continued support.
COROH’s “Ask Me, I Was There” project is unique, of course, because it provides Secret City Festival visitors with the opportunity to ask “original” Oak Ridgers about life during the Manhattan Project and the years immediately following World War II.
Hot War/Cold War
An authentic World War II Army uniform and Army overcoat on mannequins, artifacts in frames, photos, etc. of the Special Engineer Detachment — or SED — will be displayed.
The Oak Ridge (Tenn.) SED Unit contained about 1,200 drafted scientists, engineers and chemists; and a description and mission explanation (and other details) on the SED is included with the display.
This year, a special section in the SED display was added to recognize member William E. “Bill” Tewes, who died April 20, 2016.
***
“The 509th Composite Group is the USAAF story of the training, preparation [and] planning with 509th personnel, group leader Gen. Carl ‘Tooey’ Spaatz and staff who were responsible for delivering the atomic weapons to Japan. The 509th had an Oak Ridge Reunion in 2002 at [the existing] American Museum of Science and Energy,” according to Betty and Lloyd Stokes, who attended that reunion, snapped photos and met many of the 509th members at AMSE on Oct. 5, 2002.
While there, Lloyd took a LIFE magazine dated Aug. 20, 1945, with a photograph of Spaatz on the cover and obtained 48 signatures with each person’s name, rank, duty — and the plane assigned for the Japanese missions. The Stokes enjoyed a two-hour visit at the then-Garden Plaza with Enola Gay navigator Theodore “Dutch” Van Kirk and aviator Don Albury where they talked about their World War II experiences.
***
A collection of Cold War artifacts and articles (1947-1991) associated with Oak Ridge, Tenn., and Civil Defense items will be on display. Visitors can view related items such as newspapers, evacuation routes, fallout shelter plans, warden’s duties and assignments, radiation survey meters, signs and even area evacuation routes in an Oak Ridge Guide Book.
Also on display at the Secret City Festival this weekend will be a collection of Oak Ridge Manhattan Project “contractor” artifacts including guard badges, hats and uniforms related to the Corps of Engineers, the Atomic Energy Commission, Union Carbide and Martin Marietta.
Just ‘The Ticket!’
If — after all of the above — you still find yourself longing to go even further “Back to the Future” at this weekend’s Secret City Festival in Oak Ridge, Tennessee … Never Fear: The Manhattan Project AIT (American Industrial Transport) display, a contractor chosen to operate the 800-plus bus transportation system back in the days of the Secret City may be “just the ticket!”
Many artifacts, including threefold bus route schedules and photos of the ninth largest system in the U.S. at the time, is included in this one-of-a-kind collection.
Boy Scouts of America
Lloyd and Betty Stokes 72-year collection of Boy Scouts of America uniforms, compasses, badges, buttons, 1940s and ’50s Oak Ridge membership cards, artifacts and Scouting books dating back to the early 1900s is one of the largest collections of its kind in East Tennessee and was on display at the American Museum of Science and Energy from March through May in 2010 to celebrate the 100th year anniversary of BSA and the 65th birthday of Oak Ridge Boy Scout Troop No. 129.
“Lloyd collected early Oak Ridge Cub Scouting, Webelos and Boy Scouting artifacts — and has collected additional articles and artifacts from his participation as a youth and through adult service in Oak Ridge from 1948 through 2018,” according to information provided by the Stokeses.
The collection includes 1940s photographs of Scout activities at Camp Pellissippi and Camp Kromer in Oak Ridge, and the Stokeses said that Oak Ridge was in the BSA’s Talahi District before becoming the Pellissippi District of the Great Smoky Mountain Council.
“Many of the patches, memorabilia and other items were collected from attending District, Council, National, World Camporee or Jamborees. The last World Jamboree that Lloyd attended was in Calgary, Alberta Canada in 1982.
“Additionally, longtime Oak Ridge historian Bill Wilcox’s 1939 Eagle Scout card, patch and kerchief from the New York Exposition are included in the display!”
Gamble Valley/Who’s Who
A one-of-a-kind Gamble Valley Scrapbook titled “Who Is Who” in Health in Gamble Valley School in 1946-47 is expected to be on display at the Secret City Festival this weekend.
It contains student/teacher photos, health records and class groupings. This photo album is made with a quarter-inch plywood cover, and the cover title is embossed with a wood-burning pen!
The Gamble Valley Scrapbook was donated to the collection in 2012, and some early enlarged photos are included with this display.
A ‘DEDICATION’
The Stokes Collection is dedicated to the memory of Manhattan Project workers, veterans and their families in Oak Ridge who contributed, sacrificed and experienced hardships to make the many World War II Manhattan Project missions a success.
They therefore shortened World War II and, through their dedication and efforts, saved many thousands of American lives. | https://www.oakridger.com/news/20180608/stokes-collection-once-again-on-display-at-2018-secret-city-festival-june-8-and-9 |
CIMA – Center for Italian Modern Art, February 12, 2019
CIMA – the Center for Italian Modern Art (NYC) is organizing the conference:
“Methodologies of Exchange: MoMA’s Twentieth-century Italian Art (1949)”.
The conference uses the 1949 Museum of Modern Art exhibition “Twentieth-century Italian Art” as a case study to examine the various methodologies or approaches taken in recent years to explore the artistic exchange between the United States and Italy in the twentieth century. By examining the history of this exhibition and the traveling exhibitions that it spawned, we will explore the reception of Italian art and artists in the US, the growth of networks and collaborations between US dealers and artists, and the role that Italy played in the idea of art-making among American postwar artists. This particular subject allows for other questions as well: How did an important institution like MoMA shape the narrative of American modernism? How did Italy help Alfred Barr and MoMA rethink a Franco-centric vision of modern art after the war? How did the American art world deal with the problematic legacy of Fascist Modernism?
This Study Day will be held at CIMA in connection with the 107th meeting of the College Art Association and the 70th anniversary of the MoMA exhibition.
Program schedule:
10.30am
Metaphysical Masterpieces exhibition viewing and registration
11.am – 11.15am
Welcome by Emma Lewis, Executive Director of CIMA
11am–12.45pm
Morning Panel: Italian Projections
Laura Moure Cecchini – “Positively the only person to be interested in the show”: Romeo Toninelli collector and diplomat between Milan and New York. | https://www.artmarketstudies.org/conf-momas-twentieth-century-italian-art-new-york-12-feb-19/ |
From Sept. 27 to Sept. 29, community and cultural organizations will host free, public and family-friendly events that give everyone the chance to learn more about Alberta’s diverse heritage and culture.
“Our government is pleased to support Alberta Culture Days 2019. Community organizations have amazing events planned, from art walks and opera performances to dance lessons and film festivals. I encourage everyone to get out this weekend to explore their community and celebrate our province.”Leela Sharon Aheer, Minister of Culture, Multiculturalism and Status of Women
Throughout the province, 87 community and cultural groups will host free events that showcase arts, heritage, diversity and community spirit. There are 23 Indigenous and cultural organizations hosting events which will help Albertans learn more about our province’s cultural diversity.
As part of the celebration, all provincial historic sites and museums that are open for the weekend are offering free admission and special programs for Albertans.
Through a grant program, five events were selected to be official feature sites that will offer three full days of programming. They are:
Burc Intercultural Centre in Calgary
Arts Council of Wood Buffalo
Camrose Arts Society
Allied Arts Council of Lethbridge
Albert Cultivates the Arts Society
“Camrose Arts Society is super excited that Camrose has been chosen as a Feature Celebration Site. We and our community partners have put together a diverse set of activities designed to engage the many demographics in our community. People of all ages are expressing excitement that they will get to be a part of things and look forward to enjoying the opportunity to express themselves and to enjoy some of the lasting legacies made possible by the Alberta Culture Days initiative.”Jane Cherry, arts director, Camrose Arts Society
“St. Albert is thrilled to be a Feature Celebration site for Culture Days 2019 and to be able to offer a diverse palette of arts and culture programs and activities for our community. This year, more than 40 different programs/events are taking place between Sept. 27 and Sept. 29. Workshops, lessons, interactive demos and exhibits, music, dance, visual arts, theatre, film, literary programs – and much more! There’s something for everyone and it’s free for all to experience. We welcome you to join us in St. Albert for Culture Days 2019.”Heather Dolman, co-chair, St. Albert Cultivates the Arts Society
Quick facts
Alberta Culture Days started in 2008 as a celebration of Alberta’s arts and cultural communities, known as Alberta Arts Days. In 2009, it changed from a one-day event to a three-day celebration, helping to inspire the establishment of National Culture Days in 2010. In 2012, Alberta Arts Days was renamed Alberta Culture Days.
Alberta Culture Days is part of National Culture Days, a movement to raise awareness, accessibility, participation and engagement of all Canadians in the artistic and cultural life of their communities. Organizations hosting an event are encouraged to post to the National Culture Days Calendar.
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Old Saybrook economic development strategic plan a ‘great tool’
A new strategic plan for Economic Development was adopted by the town of Old Saybrook in June.
A new strategic plan for Economic Development was adopted by the town of Old Saybrook in June.
Photo: Contributed Photo / Town Of Old Saybrook
Photo: Contributed Photo / Town Of Old Saybrook
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A new strategic plan for Economic Development was adopted by the town of Old Saybrook in June.
A new strategic plan for Economic Development was adopted by the town of Old Saybrook in June.
Photo: Contributed Photo / Town Of Old Saybrook
Old Saybrook economic development strategic plan a ‘great tool’
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OLD SAYBROOK — A new, comprehensive strategic plan for economic development presents strategies and how those actions can be applied to the nine commercial areas in town.
The Board of Selectmen received a presentation of the adopted plan at the August 25 meeting. Town leaders endorsed the plan and agreed to support its implementation, according to a press release.
The Strategic Plan for a Thriving Local Economy outlines several economic development goals for Old Saybrook, according to First Selectman Carl P. Fortuna Jr. “The Board of Selectman have endorsed the plan, and we are sharing it with other town commissions with the expectation that they will consider these goals when making decisions about development proposals in town,” he said in a prepared statement.
“This will be a great tool, not only for the Economic Development Commission, but also for all commissions in town that review and make recommendations about proposed development,” Selectman Matthew Pugliese, who also chairs the EDC and led the effort to develop the plan, said in the statement.
“The plan is being distributed to all commissions and staff by the first selectman, and the EDC invites all commissions and staff to work with us on implementing the action items,” Pugliese said.
The EDC identified the following actions from the plan as priorities for implementation:
• Build a pedestrian bridge connecting Saybrook Junction to Mill Rock Road East and the Old Saybrook Business Park
• Study the wastewater disposal policy impact on commercial development
• Create bike lanes throughout town
• Complete Sidewalk Connectivity from School House Road to Ferry Point.
The strategic plan was the collaborative result of two years of research conducted by a working group of members of the Planning Commission and Economic Development Commission, the release said.
“This Strategic Plan is very comprehensive. We went through an extensive process to develop this plan and I feel we have an exceptional tool that will guide decision-making, especially regarding commercial development,” Thomas Cox, Planning Commission chairman said in the news release.
“The plan articulates our goal of pursuing development that preserves and enhances the community character, natural beauty, recreational opportunities and central location that makes us want to live here,” he said.
The two-year process required multiple steps: a review of existing state, regional and local plans; writing a draft plan, gathering stakeholder input from town commissions, residents, businesses, and community organizations; revising the plan, and petitioning the planning commission in June to adopt the final plan.
Copies of the strategic plan are available through the economic development office and it can be viewed via the town website at oldsaybrookchamber.com. | |
Kanaloa (カナロア, Kanaroa)? is a demon in the series.
HistoryEdit
In the traditions of ancient Hawaii, Kanaloa is symbolized by the squid or by the octopus, and is typically associated with Kāne. It is also the name of an extinct volcano in Hawaii. In legends and chants Kāne and Kanaloa are portrayed as complementary powers. For example: Kāne was called upon during the building of a canoe, Kanaloa during the sailing of it; Kāne governed the northern edge of the ecliptic, Kanaloa the southern; Kanaloa points to hidden springs, and Kāne then taps them out.
Kanaloa is also considered to be the god of the Underworld and a teacher of magic. Legends state that he became the leader of the first group of spirits "spit out" by the gods. In time, he led them in a rebellion in which the spirits were defeated by the gods and as punishment were thrown in the Underworld.
However, depictions of Kanaloa as a god of evil, death, or the Underworld, in conflict with good deities like Kāne (a reading that contradicts Kanaloa and Kāne's paired invocations and shared devotees in Ancient Hawaii) are likely the result of European missionary efforts to recast the four major divinities of Hawaii in the image of the Christian Trinity plus Satan. In traditional, pre-contact Hawaii, it was Milu who was the god of the Underworld and death, not Kanaloa; the related Miru traditions of other Polynesian cultures confirms this.
The Eye of Kanaloa is an esoteric symbol associated with the god in New Age Huna teaching, consisting of a seven-pointed star surrounded by concentric circles that are regularly divided by eight lines radiating from the inner-most circle to the outer-most circle.
AppearancesEdit
- Shin Megami Tensei: Devil Summoner: Vile Race
- Devil Summoner: Soul Hackers: Vile Race
- Persona 2: Innocent Sin: Tower Arcana
- Persona 2: Eternal Punishment: Tower Arcana
- Shin Megami Tensei Trading Card: Card Summoner: Vile Race
ProfileEdit
Devil Summoner: Soul HackersEdit
"A squid god of Hawaiian lore who stands against the creator-god Kane. He is also known as Tangaroa in the Polynesian religion. The god who smells evil is also a main god of the world's creation. When the gods began to fight amongst themselves, he escaped to the sea. Fish and reptiles are his children." | https://megamitensei.fandom.com/wiki/Kanaloa |
On Wednesday, the government of the Middle Eastern country, backed by the Saudi-led coalition, launched an offensive to seize al Hodeidah from the rebel Houthi movement after the latter failed to respond to the government's offer to withdraw from the port city in order to peacefully resolve the conflict. Various international organizations and rights groups have called on the Yemeni warring parties to exercise restraint amid increasing hostilities in the city.
"The military offensive on Yemen’s busy port city of Hodeidah, which began yesterday (13/08), is putting the lives of 600,000 people at risk. IOM, the UN Migration Agency, warns of the drastic impacts that the military operation is having on migrants and humanitarian access to all affected communities. With its UN and other partners, IOM urges restraint and calls for respect of International Humanitarian Law, especially the protection of civilians, including migrants," the IOM said in a statement.
"Nearly 60 IOM national staff are present in Hodeidah, with four performing critical programme functions and the rest currently on standby to join active duty, working from home for their own protection. In the coming days, IOM hopes to deploy an international presence to Hodeidah to support national staff in responding to the humanitarian needs of displaced and conflict-affected Yemenis and migrants," the statement pointed out.
Al Hodeidah is one of the most densely populated Yemeni areas. The city’s port is vital for the delivery of humanitarian aid to the Middle Eastern country, devastated by three years of conflict between the government and the Houthis.
READ MORE: Moscow: Offensive on Yemen's Hodeidah by Pro-Hadi Forces to Be Catastrophic
The conflict has resulted in thousands of people being killed and a major nationwide humanitarian crisis. According to the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), in 2018, 22.2 million Yemenis need assistance, which is one million more than in 2017.
Meanwhile, the International Committee of the Red Cross has warned that tens of thousands may flee al Hodeidah as the lifeline port braces for the siege.
"Tens of thousands of people are likely to flee the city in the coming days. The ICRC is concerned for those who were displaced already and might have to flee a second time," the health charity tweeted on Friday.
The charity said civilians were living under immense pressure, stocking up on food and fuel amid fears of an impending siege.
"Now the signs of poverty are everywhere. People live in slums in the outskirts surviving on bread crumbs they find in the garbage. With the little money they do have, they buy cooking oil in plastic bags — just enough to cook 1 meal a day," the Red Cross said.
Those who have jobs feed several families at once, it said. Beggars help those even less fortunate. Families with stricken children come to the ICRC in search of medical help because hospitals have run out of fuel. There are more and more fighters in the streets, and children are getting used to the sounds of gunfire and airstrikes. | https://sputniknews.com/middleeast/201806161065459005-un-warns-hodeidah-risks/ |
Introduction: Convolutional neural networks (CNN) are a type of machine-learning algorithm that can automate the quantitative assessment of intracranial aneurysms (IAs). Class-activation maps (CAMs) can be used to visualize which image regions trigger a trained CNN for different predictions, thus lending insight into how a CNN makes a decision.
Objective: This work investigated the use of a CNN for automatic IA segmentation and radiomic feature extraction for the quantitative assessment of IAs.
Methods: Three hundred and fifty angiographic images of pre- and post-coiled IAs were retrospectively collected. The IAs were manually contoured, and the angiographic sequences and masks were put to a CNN tasked with IA segmentation. CAMs were output to visualize the most salient aneurysmal features. IA segmentation accuracy was assessed with a receiver operating characteristic curve (ROC) using the test cohort. Radiomic features computed with a human user were compared with those computed inside the network IA prediction.
Results: CAMs indicated the IA boundary region is more predictive for segmentation than the interior region. The mean area under the ROC curve for the IA segmentation averaged over the testing cohort was 0.798 (95% confidence interval 0.747-0.824). All five radiomic features measured inside the network IA prediction were within 15% of those measured inside the human contoured IA region.
Conclusions: Automatic segmentation and quantitative assessment of IAs with a CNN has been demonstrated. CAMs can aid in understanding of CNN’s segmentation decisions. The fine-tuning of algorithms and image preprocessing based on these results may improve IA predictive models.
To foster scientific discovery and innovative research seeking to better the lives of patients suffering neurological and surgical disorders. | https://www.americanacademyns.org/funding-opportunities-detail/automated-aneurysm-detection-using-machine-learnin |
Includes review of assurance argument and evidence prior to submission deadline and written opinion regarding strengths and areas for improvement, and on-site mock visit. The mock visit will occur two to four weeks prior to the site visit. Consists of three days on-site, during which a series of interview and feedback sessions will approximately mirror those scheduled for the site visit. Debriefing sessions for the accreditation team and institutional leadership will be used to summarize observations and offer recommendations.
This service is available to HLC institutions only.
Fee: $7,500 plus reasonable travel costs from Tulsa (airfare, lodging, ground transportation).
Copyright © 2018 Council Oak Assessment - All Rights Reserved. | https://counciloakassessment.com/mock-visit-hlc-only |
Suitcase anti-recording audio signal jammer
The device is designed to protect the call area from eavesdropping. The device blocks wireless microphones, voice recorders, hard-wired microphones, and most professional digital voice recorders, including voice recorders installed in mobile phones (smartphones). Ultrasonic inaudible noise signals and acoustic speech noise signals are used to interfere with eavesdropping equipment. | https://www.jkdcsc.com/recording/80.html |
Understanding the spatial and temporal habitat use of a population is a necessary step for restoration decision making. For Chinook salmon (Oncorhynchus tshawytscha), variation in their migration and habitat use complicate predicting how restoring habitats will impact total recruitment. To evaluate how juvenile life history variation affects a population’s response to potential restoration, we developed a stage-structured model for a Chinook salmon population in a northern California river with a seasonally closed estuary. We modeled the timing of juvenile migration and estuarine use as a function of freshwater conditions and fish abundance We used the model to evaluate the sensitivity of the population to different estuary and freshwater restoration scenarios that would affect population parameters at different life stages. The population’s run size increased most in response to freshwater restoration that enhanced spawning productivity (egg and fry survival), followed by spawner capacity. In contrast, estuary restoration scenarios affected only a subset of Chinook salmon (average 15 percent), and as a result, did not have a large impact on the total recruitment of a cohort. Under current condition, estuary rearing fish were over six times less likely to survive than fish that migrate to the ocean in the spring or early summer before estuary closure. Because estuary residents experienced low survival in the estuary and in the ocean, improvements to both estuary survival and growth would be needed to increase their total survival. When life cycle monitoring data is available, life cycle models such as ours generate predictions at scales relevant to conservation and are an advantageous approach to managing and conserving anadromous salmon that use multiple habitats throughout their life cycle. | https://datadryad.org:443/stash/dataset/doi:10.6078/D1X42S |
We review the recent optimizations of gravitational N-body kernels for running them on graphics processing units (GPUs), on single hosts and massive parallel platforms. For each of the two main N-body techniques, direct summation and tree-codes, we discuss the optimization strategy, which is different for each algorithm. Because both the accuracy as well as the performance characteristics differ, hybridizing the two algorithms is essential when simulating a large N-body system with high-density structures containing few particles, and with low-density structures containing many particles. We demonstrate how this can be realized by splitting the underlying Hamiltonian, and we subsequently demonstrate the efficiency and accuracy of the hybrid code by simulating a group of 11 merging galaxies with massive black holes in the nuclei. | https://hgpu.org/?p=12829 |
Polymer porous material is a polymer material with numerous pores formed by gas dispersed in the polymer material.
This special porous structure is very good for the application of sound-absorbing materials, separation and adsorption, drug sustained release, bone scaffold and other fields.
Traditional porous materials, such as polypropylene and polyurethane, are not easy to be degraded and take petroleum as raw materials, which will cause environmental pollution.
Therefore, people began to study biodegradable open-hole materials.
Application of PLA open-hole material:
PLA open-hole material also has some disadvantages, which limit its application in the field of open-hole material, such as:
1. Crisp texture, low tensile strength and lack of elasticity of the perforated material.
2. Slow degradation rate.
If left in the body for a long time as a drug, it can cause inflammation.
3. Drain.
Low affinity for cells, if made into artificial bone or scaffold cells are difficult to adhere and proliferate.
In order to improve the shortcomings of PLA open-hole materials, blending, filling, copolymerization and other methods were adopted to improve PLA open-hole materials.
The following are several modification schemes of PLA:
1.PLA/PCL blending modification
PCL, or polycaprolactone, is also a biodegradable material with good biocompatibility, toughness and tensile strength.
Blending with PLA can effectively improve the toughness tensile strength of PLA.
The researchers found that the properties could be controlled by controlling the ratio of PCL to PLA. When the mass ratio of PLA to PCL was 7:3, the tensile strength and modulus of the material were higher.
However, the toughness decreases with the increase of pore diameter.
The PLA/PCL material is non-toxic and has potential applications in small diameter vascular tissues.
2.PLA/PBAT blend modification
PBAT is a degradable material, which has the degradability of aliphatic polyester and the toughness of aromatic polyester. The brittleness of PLA can be improved after blending with PLA.
The research shows that with the increase of PBAT content, the porosity of the open-hole material decreases (the porosity is the highest when PBAT content is 20%), and the fracture elongation increases.
Interestingly, although the addition of PBAT reduces the tensile strength of PLA, the tensile strength of PLA still increases when it is processed into open-hole material.
3.PLA/PBS blending modification
PBS is a biodegradable material, which has good mechanical properties, excellent heat resistance, flexibility and processing ability, and is very close to PP and ABS materials.
Blending PBS with PLA can improve the brittleness and processability of PLA.
According to the research, when the mass ratio of PLA: PBS was 8:2, the comprehensive effect was the best; if the PBS was added in excess, the porosity of the open-hole material would be reduced.
4.PLA/ BIOactive glass (BG) filling modification
As a bioactive glass material, BG is mainly composed of silicon sodium calcium phosphorus oxide, which can improve the mechanical properties and bioactivity of PLA.
With the increase of BG content, the tensile modulus of the open-hole material increased, but the tensile strength and elongation at break decreased.
When the BG content is 10%, the porosity of the open-hole material is the highest (87.3%).
When the BG content reaches 20%, the compressive strength of the composite is the highest.
Moreover, the PLA/BG composite porous material can deposit osteoid apatite layer on the surface and inside in simulated body fluids, which can induce bone regeneration. Therefore, PLA/BG has the potential to be applied in bone graft materials. | https://www.sikoplastics.com/news/do-you-know-about-the-application-and-modification-of-pla-open-hole-material/ |
The presence of humans on the planet Earth in the opening years of the twenty-first century has left its mark everywhere, even in the interstices of the polar ice caps and the depths of the ocean. Nowhere is immune.
In the outermost corners of the known universe we can see the beginnings of our evolution. But where are we going?
Through time there have been great cosmological and historical moments, for example when the star out of which our solar system was born collapsed in enormous heat, scattering itself as fragments in the vast realms of space. In the centre of this star the elements had been forming through a vast period of time until in the final heat of this explosion the hundred or so elements were present. Only then could the sun, our star, give shape to itself by gathering these fragments together with gravitational power and then leaving some nine spherical shapes sailing in elliptical paths around as planetary forms. At this moment Earth could take shape; life could be evoked; intelligence in its human form became possible.
This supernova event of a primary generation star could be considered a moment that determined the future possibilities of the solar system, earth and of every form of life that would ever appear on the earth.
In human history there have also been defining moments. The occasion in northeast Africa some 2.5 million years ago when the first humans stood erect and a cascade of consequences was begun that resulted in our present mode of being. Whatever talent exists in the human order, whatever genius, whatever capacity for thought, whatever physical strength or skill, all this has come to us through these earlier peoples. It was a determining moment. In our occupation of the terrestrial sphere we have continued to experience these moments of significance: when humans first controlled fire; when spoken language became embedded; when gardens were cultivated and writing and alphabets invented. We have had times of great storytellers - Homer and Valmiki - and historians Ssu-ma Ch'ien, Thucydides, Ibn Khaldrun.
So now in this transition period in the twenty-first century we are experiencing another moment of significance, but it is different from any previous one. For the first time the planet is being disturbed by humans in its geological structure and its biological functioning in a manner akin to the great cosmic forces and glaciations. We are also altering the classical civilizations and indigenous tribal cultures that have dominated the intellectual development of vast numbers of people throughout these past five thousand years. These civilizations have governed our sense of being and established our norms of reality and value and designed the life disciplines of the peoples of the earth. But the teaching and energy they communicate are unequal to the task of guiding and inspiring the future.
After some four centuries of empirical observation and experiment we see the universe as both a developmental sequence of irreversible transformations and as an ever-renewing sequence of seasonal cycles. We find ourselves becoming something of a cosmic force!
Few now doubt that degradation of the natural environment poses one of the deepest challenges to modern society. But whilst many governments and institutions have accepted that action must be taken to tackle the most urgent problems, the inexorable drive to produce and manufacture goods and improve the living conditions of so many people means that society is pushing up against a wide range of environmental limits.
Take for example the flow of materials from nature to society and back - the materials cycle - which is a fundamental part of all economies. In some places, the sheer scale of the cycle is quite remarkable: even in the most modern and efficient industrial economies, the average per capita requirement is 45-85,000kg of natural resources per year: the weekly per-person equivalent of 300 shopping bags filled with goods - or the weight of one large luxury car. Given the latest estimates of population growth, our use of resources will have to become ten times more efficient by 2030, just to keep environmental degradation at its present levels.
It is through this ability to manipulate and alter the fundamental relationships underpinning the planet's ecosystems, that we have begun to expose ourselves unnecessarily to greenlash,- where a variety of gradual and unexpected ecological changes lead to the loss or severe decline of the very ecosystem services we depend on.
In the past, environmental decision-making has been made on an ad-hoc basis, solving each particular problem in isolation from others. But now a more profound thinking is required about production and consumption patterns and how we can support different societies without engendering significant unintended shifts in the biosphere. The premise behind this thinking is that renewal and sustainability have primacy in ecosystems, just as justice has in social institutions. And as laws and institutions, no matter how efficient or well arranged, need to be reformed or abolished if they are unjust, so overexploitation and misuse of ecosystems must be prohibited if they cause harm to fundamental ecological processes.
Ecosystems are made up of mixtures of organisms, supported within sets of environmental conditions. Changes in these conditions, for example through shifts in climate, can result in the local extinction of certain species.
If these changes occur over several generations, then other species adapted to the new conditions will be able to take over their roles.
However, when changes occur rapidly, this is much less likely to occur. One reason is that embedded and often hidden within ecosystems are keystone species, that hold together vast networks of feeding relationships. The removal or loss of these keystone species can cause irreversible changes to an ecosystem. In the Sea of Azov, large-scale hydrographical changes caused by increased use of freshwater from rivers for domestic, industrial and agricultural purposes led to significant increases in salinity which caused the loss of the key planktonic food items for the major fish species and the collapse of many fisheries.
Removal of top predators, through fishing or hunting, is also detrimental to maintaining ecosystem integrity. For example, the continued exploitation of cod in the North Sea over the past century has led to a decline in larger codfish; these larger fish prey on a small bottom-dwelling fish, which in turn eat juvenile cod. The small prey fish resemble stones on the bottom; they sit and wait for the juvenile cod to "hide" behind them and then eat them. With the demise of large cod, control over these bottom-dwelling predators has been removed leading to an increase in predation on juvenile cod and a reinforcement of the decline of the cod population.
Unfortunately, these and similar experiences seem to have taught us nothing, for we can now cite case after case where a single action has had widespread, catastrophic effects. We have also witnessed the untrammelled spread of rabbits following their introduction into Australia; the purposeful introduction of African bees into South America where they have cross-bred with local species to produce a killer bee and so on. It seems that the road to ecological disaster is littered with good intentions.
There have also been instances of non-intentional introductions that have created enormous human health problems. The 1991-1993 Latin American cholera pandemic was caused by the introduction of the vibrio into rivers from ballast water taken on board in Indian coastal waters; the occurrence of cholera and hepatitis in shellfish from the coast of Alabama was caused by discharges of ballast water into Mobile Bay; and the massive 1993 Milwaukee epidemic that was caused by the introduction of a toxic algae into the drinking water. It has been estimated that the 40,000 major cargo vessels transfer 10 billion tonnes of ballast water globally each year, with 3000-4000 species transported daily across the world.
We have strong evidence that the accumulation of small, seemingly insignificant changes can lead to "flips" or dramatic shifts in the very structure and dynamic behaviour of ecosystems. Changes in climate, levels of toxic chemicals and nutrients, groundwater reduction, habitat fragmentation and loss of biodiversity often appear to alter gradually, but the response of ecosystems can be striking and sudden, moving an ecosystem into a very different, alternative state.
For example, lakes can suddenly lose their transparency from excessive inputs of nutrients, and go from clear waters, which are sustained by submerged vegetation and high levels of phytoplankton grazers, to turbid waters, where there are low levels of submerged vegetation, where levels of phytoplankton grazers are kept down by fish, and where turbidity is maintained by sediment resuspension caused by fish searching for food along the bottom.
To go from one state to another requires that some critical level is exceeded, but many of these changes can occur without any early-warning signals; they are then often hard if not impossible to reverse. Predicting which types of change will occur and over what time and space scales is fundamental to protecting our environment. Ecosystems have different levels of resilience - the rate at which they recover from short, sharp or transient shocks, resistance - the degree to which they remain unchanged when their component parts are altered and hysteresis - the degree to which conditions need to be reversed before an ecosystem will flip back to an alternate state. Long-term data series can help to resolve which responses are most likely to occur, but as these are often unavailable, comparative analyses are usually the only basis upon which observed phenomena can be interpreted, so that what will trigger a particular ecosystem response is not always clear.
Unfortunately, in many of today's environmental institutions there is still a belief that models coupled with management intervention can lead to predictable outcomes. This supposition occurs because managers have models that allow them to simulate or in a crude way anticipate the future. The implication is that all the interactions within the system are adequately understood, and that the processes directing the forward evolution of an ecosystem are known. But this is not the case.
Firstly, well-structured theories, common in many branches of science, are conspicuous by their absence in environmental management. Many of the models used include only a limited number of possible future states. Secondly, they rely on data that are highly qualitative and heterogeneous and rarely reflect the fact that complex living systems are open and hence have significant exchange of materials across their boundaries, sometimes from the other side of the planet. In the meantime we have been forced unremittingly into accepting advice based on the belief that we know enough about how ecosystems work to intervene.
Environmental degradation and changes such as global warming, the depletion of the ozone layer and the presence of toxic polychlorinated biphenyls in Antarctica have arisen because of activities within national boundaries, often thousands of miles away. But in response, national policy development has been from a standpoint of determinacy rather than complexity. The thinking is that exact predictions under highly complex circumstances can be made, a thinking which has led those involved in decision-making towards a misdirected sense of concreteness in overall policy judgement.
Greenlash undermines this confidence. Embedding resilience, resistance and hysteresis within current management regimes requires a shift in thinking from dealing with ecosystems as static entities and on an ad-hoc basis to one where ecosystems are seen as highly linked, complex dynamic systems.
Which brings us to the critical element in any discussion on sustainable development - that of people, governments and nation states.
One of the most striking aspects of today's world is the shift in balance from national to regional and global economies. Invisible on maps, a new geography of the world is slowly taking shape; it is a geography of shifts in economic and political activities, determined in large part by human migration rather than any reflection of physical or natural processes. Increasing numbers of political and economic refugees are now migrating towards urban centres in politically stable regions, and it is these mass movements of people that have exacerbated transboundary disparities in sustainable development, access to natural resources and environmental quality.
The hollowing-out of nation states, caused by the simultaneous spread of globalisation and decentralisation, means that these issues are unlikely to be properly dealt with to the detriment of many ecosystems and the people living in them.
The social consequences of this are quite explicit. Without strong institutional frameworks and clear leadership, pathological syndromes such as NIMBYism (Not In My Back Yard) and IMPism (Isn't My Problem) will flourish and lead to further significant environmental problems and disparities in ecosystem health. Accepting that environmental change is a reality creates a need for states to co-operate in understanding the effects on ecosystems of intentional and non-intentional transboundary interventions. It also gives us a framework on which to build a more stable ecological future in which renewal and sustainability have primacy.
The EEA aims to respond to the challenge by ensuring that information is made available at the right time in the right form wherever possible in all 24 languages of its member countries. At this meeting we will be launching our multilingual website to celebrate the arrival of 10 new members to the European Union. But we will try to do more than simply translate information; our aim is to work with policy-makers and the environmental leaders in each country to provide early warning signals of environmental change and emerging issues that will affect us all.
For references, please go to https://www.eea.europa.eu/media/speeches/28-04-2004 or scan the QR code. | https://www.eea.europa.eu/media/speeches/28-04-2004 |
CROSS-REFERENCE TO RELATED APPLICATIONS
STATEMENT OF FEDERAL FUNDING
FIELD OF THE INVENTION
BACKGROUND
SUMMARY OF THE INVENTION
DETAILED DESCRIPTION
Fabricating Devitrified Metallic Glass Layers
Fabricating Metallic Glass Layers
Applications for Metallic Glass Coatings
Selection of Metallic Glass-Based Materials
The current application claims priority to U.S. Provisional Application No. 62/293,210, filed Feb. 9, 2016, the disclosure of which is incorporated herein by reference.
The invention described herein was made in the performance of work under a NASA contract NNN12AA01C, and is subject to the provisions of Public Law 96-517 (35 U.S.C. 202) in which the Contractor has elected to retain title.
The present invention generally regards layers of devitrified metallic glass-based materials, and techniques for fabricating such layers.
Metallic glasses, also known as amorphous metals, have generated much interest for their potential as robust engineering materials. Metallic glasses are characterized by their disordered atomic-scale structure in spite of their metallic constituent elements—i.e. whereas conventional metallic materials typically possess a highly ordered atomic structure, metallic glasses are characterized by their disordered atomic structure. Notably, metallic glasses typically possess a number of useful material properties that can allow them to be implemented as highly effective engineering materials. For example, metallic glasses are generally much harder than conventional metals, and are generally tougher than ceramic materials. They are also relatively corrosion resistant, and, unlike conventional glass, they can have good electrical conductivity.
6
Nonetheless, the manufacture and implementation of metallic glasses present challenges that limit their viability as engineering materials. In particular, metallic glasses are typically formed by raising a metallic glass above its melting temperature, and rapidly cooling the melt to solidify it in a way such that its crystallization is avoided, thereby forming the metallic glass. The first metallic glasses required extraordinary cooling rates, e.g. on the order of 10K/s, to avoid crystallization, and were thereby limited in the thickness with which they could be formed because thicker parts could not be cooled as quickly. Indeed, because of this limitation in thickness, metallic glasses were initially largely limited to applications that involved coatings. Accordingly, the present state of the art can benefit from improved techniques for implementing layers of metallic glass.
6
providing a liquid phase metallic glass having a critical cooling rate of less than 10K/s;
applying a liquid phase metallic glass to an object, wherein applying the coating layer comprises immersing at least a portion of the object such that the object is wetted by the liquid phase metallic glass to form a layer of liquid phase metallic glass on the outer surface thereof; and
solidifying the layer of liquid phase metallic glass-forming alloy such that a solid phase devitrified metallic glass-forming coating is formed therefrom.
Systems and methods in accordance with embodiments of the invention implement layers of devitrified metallic glass-based materials. In some embodiments, a method of fabricating a layer of a devitrified metallic glass includes:
In other embodiments the grain size of the coating is nanocrystalline with an average grain size from 10 nanometers to 1000 nanometers.
In still other embodiments the grain size is greater than 1 micrometer.
In yet other embodiments the coating crystallizes during cooling from the liquid phase.
In still yet other embodiments the method further includes applying an external heat source to heat the object during solidifying.
quenching the liquid phase at a cooling rate faster than the critical cooling rate of the liquid phase metallic glass to form a solid phase metallic glass coating;
heating the solid phase metallic glass coating to a processing temperature above the glass transition temperature of the metallic glass and holding the metallic glass coating at the processing temperature to form a devitrified metallic glass-forming coating; and
cooling the devitrified metallic glass-forming coating to below the glass transition temperature.
In still yet other embodiments the method further includes
In still yet other embodiments the devitrified coating has a hardness that is at least 10% higher than the amorphous phase of the same alloy.
In still yet other embodiments the devitrified coating has a Young's modulus that is at least 10% higher than the amorphous phase of the same alloy.
In still yet other embodiments the metallic glass-forming alloy is applied to an object that is at a higher temperature than the liquidus temperature of the metallic glass-form ing alloy causing it to melt and wet the object.
In still yet other embodiments the devitrified coating has a lower surface roughness than the object to which the liquid phase metallic glass is applied.
In still yet other embodiments the immersion of the object comprises one of the methods selected from the group consisting of dipping, pouring and spraying.
In still yet other embodiments the object being coated is made from metal, polymer, ceramic, glass, or mixtures thereof.
In still yet other embodiments the thickness of the coating layer is greater than 50 micrometers.
In still yet other embodiments the thickness of the coating layer is greater than 1 mm.
In still yet other embodiments the coating process is done under a vacuum or inert environment.
In still yet other embodiments the coating does not exhibit a glass transition temperature when heated.
In still yet other embodiments the method further includes spinning the object during the applying and solidifying.
In still yet other embodiments the object comprises one of aluminum, titanium, steel, cobalt, graphite, quartz, silicon carbide, and mixtures thereof.
In still yet other embodiments the metallic glass has a melting temperature of less than 800° C.
6
providing a liquid phase metallic glass having a critical cooling rate of less than 10K/s and a melting temperature of less than 800° C.;
applying a liquid phase metallic glass to an object, wherein applying the coating layer comprises immersing at least a portion of the object such that the object is wetted by the liquid phase metallic glass to form a layer of liquid phase metallic glass on the outer surface thereof; and
solidifying the layer of liquid phase metallic glass-forming alloy such that a solid phase devitrified metallic glass-forming coating is formed therefrom.
Some other embodiments are also directed to methods of fabricating a layer of devitrified metallic glass including:
Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the invention. A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.
Turning now to the drawings, systems and methods for implementing layers of devitrified metallic glass-based materials are illustrated. In many embodiments the systems and methods comprise dipping an object into a molten reservoir of a metallic glass-based material to form a layer on a portion of the object, and cooling the layer of metallic glass-based material at a rate slow enough to ensure devitrification of the material.
For the purpose of this invention, amorphous metal is a multi-component metal alloy that exhibits an amorphous (non-crystalline) atomic structure. These alloys can also be called metallic glasses, as they exhibit a glass transition temperature. A de-vitrified metallic glass is one that has a fully or mostly crystalline structure either due to insufficient cooling from the liquid or from heating with the intent of crystallization. For the purposes of this patent application, the term ‘metallic glass-based material’ shall be interpreted to be inclusive of ‘amorphous alloys’, ‘metallic glasses’, and ‘metallic glass composites’, except where otherwise noted. Metallic glass composites are characterized in that they possess the amorphous structure of metallic glasses, but they may also include crystalline phases of material within the matrix of the amorphous structure.
FIG. 1
FIG. 1
6
Amorphous metals are a unique class of metal alloys known for having remarkable mechanical properties due to their lack of microstructure (e.g., an ‘amorphous’ microstructure). However, to attain this ‘amorphous’ microstructure it is necessary to rapidly cool the alloy from its molten state to below its solidification temperature at a rate known as the ‘critical cooling rate’ to avoid crystallization of the material. A diagram of a typical crystallization curve for a metallic glass material is shown in . A ‘critical cooling rate’ refers to how fast a liquid phase metallic glass must be cooled in order to avoid the crystallization region shown in and form the corresponding solid phase metallic glass, i.e., having an amorphous crystalline structure. Typical cooling rates for metallic glasses range from above 10K/s, and even low critical cooling rates are typically above 100 K/s.
The critical cooling rate of a metallic glass is associated with a material's ‘glass forming ability,’ a term that references a measure as to how easy it is to form a solid phase metallic glass. In typical applications, it is desirable to use metallic glasses having low critical cooling rates because such materials provide the user more time to cool the material during processing before it crystallizes. This additional time can be used for forming, or to obtain thicker coatings or objects having larger volumes. However, as even the best glass forming alloys have critical cooling rates for metallic-glass materials that are on the order of 1-10 K/s, having to operate within this narrow region greatly limits the widespread commercialization of these materials, and how these materials may be integrated into applications where they otherwise might offer a substantial benefit compared with existing materials (either in cost, mechanical properties or processing ability).
For example, amorphous metals have been cast into net-shaped parts, similar to plastics, that can be used for electronic cases, golf clubs, medical devices etc. These alloys are typically referred to as bulk metallic glasses (BMGs). However, even these ‘bulk’ alloys are limited to cast parts having thicknesses on the order of millimeters or centimeters. Most amorphous metals are limited to use in thin sheets with thicknesses between 10-100 micrometers produced through melt spinning liquid onto a rotating copper wheel. These ribbons have excellent magnetic properties and have been used as transformer cores and as anti-theft identification tags, but the materials cannot be used to make thicker objects.
Another area where amorphous metals have experienced large growth is in coatings. Many techniques may be used to implement layers of metallic glass, e.g. metallic glass coatings on objects. To account for the critical cooling rates of most metallic glasses, these coatings are typically produced through a thermal spraying process, such as high velocity oxy-fuel (HVOF) or wire arc spraying, and they produce a hard and durable coating primarily used for protecting pipes and drill bits in the oil and gas industry. Other techniques for fabricating coatings from amorphous metals have also been attempted, including plating, evaporation and sputtering. However, many of the techniques that have been used thus far exhibit a number of shortcomings. For example, thermal spraying techniques have been used to implement metallic glass coatings. Thermal spraying techniques generally regard spraying heated material onto an object to establish a coating. In some thermal spraying techniques, metallic glass in a powdered form of micrometer sized particles is sprayed onto the object to be coated. In other thermal spraying techniques, metallic glass in a wire form is heated to a molten state and thereby applied to the object to be coated. However, these thermal spraying techniques are limited insofar as they usually result in a coating that has a very rough surface finish; in many instances it is desirable for the coating to have a smooth finish. Moreover, thermal spraying techniques generally can be fairly time-consuming. Additionally, these techniques may be fairly expensive to implement because the feedstock, e.g. the metallic glass in powdered form, can be costly. Sputtering techniques and chemical vapor deposition techniques have also been used to implement metallic glass coatings; but these techniques have their own shortcomings. For example, sputtering techniques and chemical vapor deposition techniques generally regard a layer by layer deposition of material on an atomic scale. With this being the case, such processes can be extremely slow. Moreover, the thickness of the coating layer can be substantially limited, in many cases to less than 10 micrometers.
One technique that has not been explored is immersion coating. Immersion coating involves the dipping or immersion of parts into molten baths of glass-forming alloys to form a coating. This technique offers a solution to an area of coating technology that cannot be easily solved using spray coating, plating or evaporation. In this case, a part is submerged into a bath of molten metal in a vacuum chamber or is sprayed with a liquid of the same metal (different from thermal spray coating which uses atomization). After a short time, the part is removed from the bath or continuously passes through the bath and is cooled via blowing gas, conduction into the part, quenching in a liquid or radiation in air. This technique allows for a coating of between 0.1-1 millimeters to be applied to a part without having to use thermal spraying or deposition techniques, drastically decreasing the coating time. Moreover, because the coating goes on as a liquid layer and is allowed to drip off, the coating is smooth and durable after hardening.
The reason immersion coating has not been considered for use with metallic glass-based materials is that current techniques are evaluated with an extensive focus on ensuring a fast cooling rate to facilitate the formation of the solid phase metallic glass. The instant application identifies that many metallic glass-based materials have properties in their devitrified (i.e., crystallized) form that are themselves novel, and that many metallic glass-based materials have the further advantage of having very low melting temperatures (e.g., <1200° C.), which make these devitrified metallic glass-based materials uniquely suited for use as coating materials. Accordingly, in the current technique, coatings are applied in such a way to ensure that they do not form a fully amorphous layer but rather crystallize into a mostly or fully crystalline coating, which results in properties that are similar, but completely distinct from a fully amorphous metallic-glass based material.
Thus, in many embodiments, a liquid phase metallic glass-based material is applied to an object in a manner that allows the metallic glass-based material to wet the object, and the liquid phase metallic glass is thereafter allowed to cool, but at a rate slow enough such that the metallic glass devitrifies to form a layer of solid phase devitrified metallic glass coating. The layer of solid phase devitrified metallic glass can form in spite of the fact that a relatively substantial volume of liquid phase metallic glass may be used to coat the object, because the normal limitations concerning critical cooling rates do not apply. Processes and materials for fabricating such devitrified metallic glass layers are discussed in greater detail below.
Many embodiments are directed to systems and methods for forming layers and coatings of devitrified metallic glass-based materials. In various such embodiments, liquid phase metallic glass is applied such that it wets an object in relatively substantial volumes by immersion, and is thereafter forced to cool at a cooling rate slower than the material's critical cooling rate such that a solid phase devitrified metallic glass layer is formed. As discussed in the embodiments below, several methods may be used to form the devitrified metallic glass-based material coatings.
FIGS. 2A to 2C
As shown in , in various embodiments the immersion technique involves melting a volume of metallic-glass forming alloy into a liquid. Once a molten metallic-glass forming alloy is formed the object is immersed in the molten alloy feedstock such that a volume or quantity of liquid phase metallic glass is deposited on the outer surfaces of the object.
FIGS. 2B
FIG. 2B
FIG. 2C
2
Once a suitable quantity of liquid phase metallic glass is applied to the outer surface of the object the layer of liquid phase metallic glass is then cooled, however, rather than quenching the alloy rapidly as is typically required of processing metallic glasses, in embodiments the temperature of the liquid phase metallic glass layer is cooled sufficiently slowly to ensure the formation of a solid phase devitrified metallic glass layer. This generally requires a cooling rate slower than the critical cooling rate, such that the metallic glass alloy passes through its crystallization region, as shown in and C. As will be discussed in greater detail below in reference to specific types of metallic glass-based materials, different metallic glass materials will have different glass forming abilities and thus critical cooling rates. demonstrates a TTT curve from a moderate glass forming alloy where a specific cooling rate barely passes through the nose of crystallization, while the TTT curve in from a weak glass forming alloy shows that the same cooling rate passes well into the crystallization region of the material. While both will devitrify in the moderate class former, where the crystallization region is only barely entered the crystallization will occur more slowly resulting in a nanocrystalline structure, whereas in the poor former the coating will have a grain size larger than the nanometer scale. Accordingly, by selecting material and/or cooling rate it is possible to control the size and nature of the crystallization domains of the final coating.
FIGS. 2A to 2C
FIGS. 3A and 3B
Although describe a process where a single cooling step is used, it should be understood that other multi-step processes may be used to obtain solid phase devitrified metallic glass layers. For example, as summarized in , in various embodiments an alloy may be used that is an excellent glass forming alloy where quenching the coating from the liquid to below the glass transition forms an amorphous layer. In such cases the layer must then be heated after quenching to alloy for crystallization of the coating before quenching again back to room temperature.
FIG. 3B
Accordingly, in such embodiments a process for forming solid phase devitrified metallic glass layers may involve melting a volume of metallic-glass forming alloy into a liquid. Once a molten metallic-glass forming alloy is formed, immersing an object in the molten alloy feedstock such that a volume or quantity of liquid phase metallic glass is deposited on the outer surfaces of the object. Once a suitable quantity of liquid phase metallic glass is applied to the outer surface of the object the layer of liquid phase metallic glass is then cooled to form a solid phase metallic glass layer. This generally requires a cooling rate faster than the critical cooling rate (as shown in ).
Any suitable technique can be used to cool the layer of liquid phase metallic glass. For example, the metallic glass layer can be spun to facilitate cooling by convection. Cooling gases may also be used to cool the liquid phase metallic glass. In some embodiments, the cooling of the liquid phase metallic glass layer occurs largely by thermal conduction, e.g. through object that was coated. Of course, although certain techniques for cooling the liquid phase cooling layer are mentioned, it should of course be understood that any suitable technique(s) for cooling the liquid phase metallic glass layer can be implemented in accordance with embodiments of the invention. In many embodiments, the application of the liquid phase metallic glass and its cooling is done with such rapidity, that even where the object that is coated with liquid phase metallic glass has a lower melting point than the metallic glass, a metallic glass layer can still be developed on the object, i.e. the liquid phase metallic glass does not melt the object. In particular, liquid phase metallic glass can be applied to the object in relatively substantial volumes and cooled all prior to the thermal energy diffusing through the coated object to melt it.
FIG. 3A
FIG. 3B
In such a process, as shown in , once the solidified metallic glass coating is obtained, the object is reheated to above the glass transition temperature such that the material passes through its crystallization region (as shown in ) thus resulting in devitrification of the solid phase metallic glass-based layer. Once devitrification has occurred, the coating is quenched again to form the final coated object.
Regardless of the specific process chosen, in the final step the heating and/or cooling rate of the metallic glass layer is controlled to ensure devitrification of the metallic glass-based material. Any suitable technique can be used to control the cooling of the layer of liquid phase metallic glass to ensure devitrification. For example, the coated object may have its temperature purposefully elevated, such as by an oven, kiln or other heating element. In addition, suring cooling other techniques may be used to improve the quality of the coating finish. For example, the metallic glass layer can be spun to eliminate excess liquid, which can inhibit the quality of the surface finish. The formation of layers of metallic glass can also be highly sensitive to the development of oxide layers or other contamination that can adversely impact the final material properties. In particular, many CuZr-based alloys, Ti-based alloys, and Zr-based alloys are sensitive in this manner. Thus, in many embodiments, the application of liquid phase metallic glass and its cooling may occur in an inert environment. For instance, the application of the liquid layer and its cooling can occur in a chamber that is substantially filled with one of: argon, helium, neon, nitrogen and/or mixtures thereof (argon, helium, neon, and nitrogen being relatively inert elements).
The ability to develop metallic glass layers without reference to critical cooling rates allows for the use of relatively substantial volumes of liquid phase metallic glass. This can offer many advantages. For example, using relatively substantial volumes of liquid phase metallic glass can allow thicker layers of metallic glass to form, which can provide for greater structural integrity. Indeed, where a part is coated in a metallic glass layer, if the metallic glass layer is sufficiently thick, the part with the coated layer can perform in many ways as if it were entirely constituted from the metallic glass.
FIGS. 4A and 4B
FIG. 4A
FIG. 4B
FIG. 4B
Additionally, using relatively substantial volumes of liquid phase metallic glass can allow for the final layer of metallic glass to have a smooth finish, which in many instances can be desirable. For example, smooth finishes generally provide for appealing aesthetics. Moreover, smooth surface finishes can also be used to facilitate laminar flow, e.g. where the inside of a pipe that is to facilitate the transportation of liquid has a smooth finish. Furthermore, the smooth layer of metallic glass can be used to mask the rough surface of the object that was coated. illustrate this principle. In particular, depicts a diagram showing a substrate with a rough surface finish, which is then coated by metallic glass, to develop a smooth surface finish in accordance with embodiments of the invention. In effect, the liquid phase metallic glass, when applied, can fill into any pores or openings that define the substrate's rough surface. provides a set of images of this result with respect to a machined Ti-6-4 surface. As seen in the metallic glass coated Ti-6-4 surface appears much more smooth than the original part that was coated in the metallic glass, and particularly eliminates the machining flaws.
Accordingly, in some embodiments, the quantity of liquid phase metallic glass that is applied is such that the surface tension of the liquid phase metallic glass causes the coating layer to have a smooth surface, and in many embodiments, a sufficient quantity of liquid phase metallic glass is applied such that the surface of the developed coating layer is smoother than that of the object that was coated with the coating layer. The surface tension of a liquid refers to its contractive tendency; it is generally caused by the cohesion of similar molecules, and is responsible for many of the behaviors of liquids. Thus, when a sufficient quantity of liquid phase metallic glass is applied, cohesive interactions between the constituent elements can cause an even distribution of the coating layer across the surface of the layer, i.e. the coating layer can have a smooth surface. By contrast, when thermal spraying techniques are used to implement layers of metallic glass, the metallic glass is typically sparsely distributed on to the object to be coated such that surface tension effects do not take place across the coating layer; as a consequence, thermal spraying techniques generally result in rough surface finishes.
Of course, it should be noted that, any suitable measure may be used to ensure the application of a relatively substantial volume of liquid phase metallic glass in accordance with embodiments of the invention. For instance, in some embodiments, a sufficient quantity of liquid phase metallic glass is applied such that a coating layer having a thickness of greater than approximately 50 micrometers develops. For example, in many embodiments liquid phase metallic glass is applied to develop a coating layer having a thickness as high as 1 mm or more. Of course, although a particular threshold quantity is mentioned, it should be understood that any suitable threshold value can be implemented in accordance with embodiments of the invention.
Techniques for applying liquid phase metallic glass are now discussed below.
FIG. 5
100
102
104
Liquid phase metallic glass can be applied by immersion to objects in many ways in accordance with embodiments of the invention. For example, as shown in , an object () can be dipped into a bath () of liquid phase metallic glass () in accordance with embodiments of the invention.
FIG. 6A
FIGS. 6B and 6C
FIG. 6B
FIG. 6C
200
202
As stated previously, the layer of liquid phase metallic glass can also be spun to facilitate the cooling and/or to eliminate excess material. demonstrates spinning an object () that has been dipped in a bath of liquid phase metallic glass () to eliminate excess material and/or to facilitate cooling. Indeed, in many embodiments, the layer of liquid phase metallic glass is spun primarily to get rid of excess liquid, which can inhibit the quality of the surface finish. show exemplary embodiments demonstrating the utility of such spinning techniques. Specifically, shows an uncoated Ti surface (right), a Ti surface that has been immersion coated without spinning (center) and shows significant surface defects as the result of running and dripping of the material, and a Ti surface that has been immersion coated with spinning (left) and shows substantial improvement. Also included in is an image of a steel surface that has been immersion coated with spinning to show that the improvement occurs across multiple material systems.
FIG. 7
300
302
304
304
306
306
308
306
306
310
312
314
304
310
314
304
310
A system for dipping an object in a bath of liquid phase metallic glass in an inert environment to form a layer of devitrified metallic glass in accordance with embodiments of the invention is illustrated in . In particular, the system () includes an airlock () that initially houses the object(s) to be coated (). When the object () is ready to be coated, it is transferred to the chamber for depositing the metallic glass layer (). The chamber () is substantially an inert environment. A purging line () is used to substantially fill the chamber () with an inert substance such as argon, helium, neon, and/or nitrogen, and thereby create and preserve the substantially inert environment. The inert environment can prevent the contamination of the coating layer. The chamber further includes a bath of liquid phase metallic glass (), heating elements () to heat the bath of liquid phase metallic glass, and a source for emitting cooling gas () to cool an object coated in liquid phase metallic gas. The object () is shown having been dipped in the bath of liquid phase metallic glass (), and ready for cooling by the source for emitting cooling gases (). Of course, it is not necessary that the entire object be dipped in the bath of liquid phase metallic glass; in many embodiments, at least a portion of the object is dipped in the liquid phase metallic glass. As can be inferred, dipping the object () (or at least a portion of it) in the bath of liquid phase metallic glass () is sufficient to apply a relatively substantial volume of liquid phase metallic glass to the object, e.g. such that a smooth coating layer can develop.
It should of course be understood that any suitable metallic glass can be used, and that any suitable technique for cooling can be used in accordance with embodiments of the invention. For example, it is not necessary to use a source of cooling gases to cool the layer of metallic glass. The layer of metallic glass can be cooled simply by thermal conduction for instance.
Generally, these dipping techniques can be substantially advantageous in many respects; for example, they can provide for an efficient and economical way of developing a smooth devitrified metallic glass coating.
FIG. 8
500
502
504
506
508
510
512
Although embodiments of techniques for immersion coating by dipping have been described above, liquid phase metallic glass can also be poured over an object to develop a layer of devitrified metallic glass in accordance with embodiments of the invention. A system for pouring liquid phase metallic glass over an object develop a layer of metallic glass is illustrated in . In particular, the system () includes a chamber for depositing the metallic glass alloy (), a source of liquid phase metallic glass (), a vat for receiving excess poured liquid phase metallic glass alloy (), a purging line () to maintain a substantially inert environment, and a source for cooling the layer of liquid phase metallic glass (). Accordingly, a layer of devitrified metallic glass can be formed in accordance with embodiments of the invention by pouring the liquid phase metallic glass over an object (), and cooling the layer of liquid phase metallic glass sufficiently slowly to form a solid phase layer of devitrified metallic glass. Again, it is not necessary that liquid phase metallic glass be poured over the entire object; in many embodiments, liquid phase metallic glass is poured over at least a portion of the object. As before, any suitable metallic glass forming alloy can be used, and any suitable cooling techniques can be used, in accordance with embodiments of the invention. For example, it is not necessary to use a source of cooling gases to control the temperature of the layer of metallic glass. Such pouring techniques can also provide for an efficient and economical way to develop devitrified metallic glass layers. The above-described dipping and pouring techniques can be used in a myriad of applications whereby devitrified metallic glass coating layers are desired; some of these applications are now discussed below.
The above described techniques can be used to effectively and efficiently implement metallic glass coatings, which can possess favorable materials properties. For example, devitrified metallic glasses can be developed to possess corrosion resistance, wear resistance, and sufficient resistance to brittle failure, and otherwise favorable structural properties. Additionally, as mentioned above, techniques in accordance with embodiments of the instant invention can implement devitrified metallic glass coating layers that have a smooth surface, which can be aesthetically appealing and/or utilitarian. Thus, in many embodiments of the invention, objects are coated with devitrified metallic glass layers to enhance the functionality of the object. For example, in many embodiments, electronic casings are coated with devitrified metallic glass layers using any of the above described techniques.
FIG. 9
FIG. 5
600
602
A system for developing a devitrified metallic glass coating for a phone casing in accordance with embodiments of the invention is illustrated in . In particular, the system (), and its operation, is similar to that seen in, and described with respect to, , except that a phone case () is the object that is coated in a devitrified metallic glass layer. In this way, the coating can conform to the shape of the casing, and accordingly, it can be as if the casing had been fabricated entirely from the devitrified metallic glass. However, the overall cost of production of the casing coated in devitrified metallic glass may be cheaper than if the casing had been entirely fabricated from devitrified metallic glass. Additionally, if the thickness of the devitrified metallic glass coating layer is thinner than the plastic zone size of the devitrified metallic glass, the coating layer can be resistant to cracking. Further, if the base material of the coated object is relatively soft (e.g. if it is made from aluminum), the softness can provide for an enhanced toughness for the coated object as a whole. In this way, the coated object can have better structural properties as compared to if it were made from either the metallic glass or the soft base metal individually. Generally, the devitrified metallic glass coating can provide improved structural characteristics and an improved cosmetic finish.
Of course it should be understood that although the coating of a phone casing has been described above, any suitable object can be coated using the techniques described herein in accordance with embodiments of the invention. For example, devitrified metallic glass coating layers can be deposited on any of the following objects in accordance with embodiments of the invention: laptop case, electronic case, a mirror, sheet metal, metal foams, graphite parts, parts made from refractory metals, aluminum parts, pyrolyzed polymer parts, titanium parts, steel parts, knives, gears, golf clubs, baseball bats, watches, jewelry, miscellaneous metal tools, biomedical implants, etc. Generally, any suitable objects can take advantage of the above-described techniques for developing devitrified metallic glass layers. Note that biomedical are especially well-suited for the techniques described herein as they can take advantage of the hardness and corrosion resistance that devitrified metallic glasses can offer, as well as their resistance to corrosion. Resistance to corrosion is particularly important in biomedical applications because of the potential for corrosion fatigue, which can result from corrosive biological environments. Accordingly, biomedical parts can be fabricated from metal, coated with devitrified metallic glass; in this way, the devitrified metallic glass can provide resistance to corrosion, while the underlying metal can be sufficiently resistant to corrosion fatigue. Additionally, porous foams are also well suited for the dipping techniques described above, which can enable a substantial portion of the exposed surfaces within a porous foam to be sufficiently coated.
Of course it should be understood that the application of relatively substantial volumes of liquid phase metallic glass to an object can be instituted in ways other than those corresponding to the immersion techniques described above in accordance with embodiments of the invention. For instance, spraying techniques can be implemented.
FIG. 10
700
702
704
706
708
706
A system for coating the inside of a pipe with a metallic glass layer using a spraying technique in accordance with embodiments of the invention is illustrated in . In particular the system () includes a vessel () for housing a liquid phase metallic glass, a tubing () for transporting the liquid phase metallic glass, and a spray mechanism () for spraying liquid phase metallic glass to the inside of a piping (). The spray mechanism () applies relatively substantial volumes of liquid phase metallic glass such that a smooth coating layer can develop. Any suitable techniques for controlling the temperature of the applied liquid phase metallic glass so that it forms a solid phase devitrified metallic glass can be implemented. As mentioned above, coating the inside of a piping with a devitrified metallic glass layer can be beneficial in a number of respects. For example, devitrified metallic glass coatings have advantageous structural characteristics as well as corrosion resistance. Moreover, the smooth coating layer can promote laminar flow while the pipe is in operation.
It should of course be understood that although several techniques have been discussed above with respect to developing devitrified metallic glass coating layers, by applying relatively substantial volumes of liquid phase metallic glass, any number of techniques can be used to do so in accordance with embodiments of the invention. In essence, the above-descriptions are meant to be illustrative and not comprehensive.
FIGS. 11A and 11B
FIG. 11B
800
804
802
806
808
812
812
814
814
812
Additionally, although much of the above-discussion has been focused on developing devitrified metallic glass coating layers, free-standing devitrified metallic glass layers can also be developed in accordance with embodiments of the invention and this is now discussed. In many embodiments, free standing sheets of devitrified metallic glass layers are fabricated by depositing relatively substantial volumes of liquid phase metallic glass onto a substrate, e.g. such that a smooth coating layer can develop, allowing the liquid phase metallic glass to cool and thereby form a solid phase layer of devitrified metallic glass, and separating the solid phase metallic glass from the substrate layer. A system for fabricating free-standing sheets of devitrified metallic glass is illustrated in . In particular, the system () includes a chamber that houses a substantially inert environment, a purging line () used to substantially fill the chamber () with an inert substance such as argon, helium, and/or neon, and thereby create and preserve the substantially inert environment, a vessel () containing liquid phase metallic glass, heating elements () to maintain the liquid phase metallic glass, temperature control elements to control the temperature of the poured liquid phase metallic glass, and a substrate (). In essence, liquid phase metallic glass from the vessel is poured onto the substrate (), and is then allowed to cool so as to form a layer of solid phase devitrified metallic glass (). In the illustrated embodiment, it is shown that the substrate is disposed on a conveyer belt that transports the poured liquid phase metallic glass to the temperature control elements. Thereafter, as shown in , the solid phase devitrified metallic glass layer () is removed from the substrate (). The devitrified metallic glass layer can be removed using any suitable techniques, e.g. cutting. Thus, a free standing layer of metallic glass can be obtained. Of course, as before, any metallic glass can be used, and any temperature control techniques can be used.
FIG. 12
FIG. 12
FIGS. 11A and 11B
900
902
In many embodiments of the invention, forming techniques are introduced into processes for fabricating devitrified metallic glass layers. For example, rolling wheels can be used. A rolling wheel used to form a free standing sheet in accordance with embodiments of the invention is illustrated in . The system () depicted in is similar to that seen in except that it further includes a rolling wheel (). The rolling wheel can be used to further form the devitrified metallic glass layer into a desired shape prior to its solidification. Of course it should be understood that any forming tools can be used in accordance with embodiments of the invention, not just rolling wheels. Additionally, it should be understood that such forming techniques can be used in conjunction with any of the above-described techniques in accordance with embodiments of the invention, not just those with respect to forming free standing layers of devitrified metallic glass.
6
Although the above description has focused on the methods of immersion coating layers of a solid phase devitrified metallic glass-based material on an object, it should be understood that not all metallic glass-based materials can be used with methods. Indeed, only metallic glass-based materials which can be formed into a fully amorphous ribbon may be used with the current systems and methods, that is, alloys that can be form fully amorphous in at least a 15 micron thick ribbon via melt spinning or splat quenching, or other fast cooling rate laboratory scale process (˜10K/s).
40
40
7
10
3
45
45
5
2
3
42.5
42.5
41.5
41.5
7
7
3
41.5
41.5
7
7
3
44
44
5
3
4
46.5
46.5
7
43
43
7
7
41.5
41.5
7
10
44
44
7
5
43
43
7
7
44
44
7
5
40
40
10
10
41
40
7
7
5
42
41
7
7
3
47.5
48
4
0.5
47
46
5
2
50
50
33.18
30.51
5.33
22.88
8.1
40
25
30
5
40
25
8
9
18
45
16
9
10
20
41.2
13.8
12.5
10
22.5
52.5
5
17.9
14.6
10
58.5
2.5
15.6
12.8
10.3
55
30
10
5
65
17.5
7.5
10
36.6
31.4
7
5.9
19.1
35
30
8.25
26.75
6
Suitable metallic glasses include copper-zirconium based metallic glasses, titanium-based metallic glasses, iron-based metallic glasses, nickel-based metallic glasses, and zirconium based metallic glasses. In many embodiments, the metallic glass is one of: CuZrAlBeNb, CuZrAlYNb, CuZrAl7Be5Nb3, CuZrAlBeNb, CuZrAlBeCr, CuZrAlNiBe, CuZrAl, CuZrAlAg, CuZrAlBe, CuZrAlBe, CuZrAlBe, CuZrAlNi, CuZrAlBe, CuZrAlBeCo, CuZrAlBeCO, CuZrAlCo, CuZrAlY, CuZr, TiZrNiBeCu, TiZrBeCr, TiZrNiCuBe, TiZrNiCuBe, ZrTiCuNiBe, ZrTiCuNiAl, ZrNbCuNiAl, ZrCuAlNi, ZrCuAlNi, ZrAlCo, ZrTiNbCuBe, ZrTiCuBe, and mixtures thereof. These alloys have demonstrated sufficient glass forming ability. Of course, although several metallic glass alloys are listed, embodiments in accordance with the instant invention are not limited to using these alloys. Indeed, any suitable metallic glass having a critical cooling rate of no greater than 10K/s can be used in accordance with embodiments of the invention.
Importantly, because the method does not rely on high cooling rates such that a solid phase metallic glass coating results, conventional cooling processes may be used. Moreover, it is not necessary to restrict the choice of metallic glass composition to those with relatively low critical cooling rate, e.g., a ‘bulk metallic glass’, where the critical cooling rate of the metallic glass alloy is less than approximately 1000 K/s. Of course although a particular threshold value is referenced, any suitable metallic glass can be implemented in accordance with embodiments of the invention. Additionally, although the critical cooling rate can be used as a measure of glass forming ability in accordance with embodiments of the invention, any suitable measure of glass forming ability can be used. For instance, the thickness of a part that can be readily formed from a metallic glass using standard casting procedures can be used to judge the metallic glass's glass forming ability, as described above. Accordingly, in many embodiments, a metallic glass is used that can readily be cast into parts having a thickness of greater than approximately 15 micron thick.
FIG. 13
Metallic glass forming alloys are designed around deep eutectics, also known as very low melting temperature. One exemplary alloy system is the Ti—Be binary. As shown in the phase diagram provided in , this system shows a very deep eutectic temperature at 30 atomic % Be. This is advantageous when creating a coating through immersion because the lower melting temperature prevents melting of the object being coated. Also, unlike other low melting temperature alloys, metallic glasses almost always crystallize into ordered, hard, high-strength phases, which are advantageous for structural coatings. Moreover, these crystalline metallic glass forming alloys are typically brittle and would be hard to machine or apply as a coating without the current technique
6
FIG. 14
In particular, limiting the metallic glass-based materials to those that can be formed into an amorphous part at critical cooling rates <10K/s, in accordance with embodiments allows for an immersion system and process that can take advantage of several properties of these alloys that would not be possible with conventional alloys or poorer glass forming alloys. For example, as shown in , metallic glass-forming alloys are typically designed around low melting temperatures (e.g., typically less than 800° C.), which means that they can be used as a molten bath or immersion without melting a part that is subjected to the coating process, i.e., they can be applied at relatively low temperatures. Indeed, nearly all BMGs have lower melting temperatures than their constituents, e.g., alloys with melting temperatures <1200° C. What is more, the low melting temperature of these alloys is unaffected by their crystal structure.
FIG. 15
In the current patent, coatings are applied to alloys that could be formed amorphous with sufficient cooling rate, but are purposely forced to form crystalline structured to take advantage of the properties of the crystalline state. This process is helped by the fact that metallic glass-forming alloys undergo a slow crystallization process. Specifically, shows three x-ray diffraction scans from the same alloy cooled at different rates, each showing varying levels of crystallization. This means that the nature of the crystal structure of the coatings formed from these materials can be controlled to form a desired structure (e.g., a nanocrystalline structure, which is known to have very high strength due to the Hall-Petch relation).
FIG. 16
Finally, it has been surprisingly discovered that devitrified metallic glass forming alloys are comprised of very hard, ordered phases, which improve wear resistance and hardness compared to amorphous coatings. This is confirmed by the data table presented in , which provides a comparison of a family of metallic glass-based materials in amorphous (A), crystalline (X) and composite (C) states. As shown, crystallization does not reduce hardness and in some cases actually improves it. Accordingly, the de-vitrified coating will have very high hardness and high stiffness, harder and stiffer than many metallic glasses, which is advantageous for many applications.
FIG. 17
These observations were further confirmed by a direct study of a Ti-crystalline BMG coating. As shown in , which summarizes the results from the study, the application of a devitrified Ti-based BMG coating increases the hardness of Ti-6-4 by 25%. Moreover, the hardness of the coating is almost the same as the hardness of the same injection molded BMG. Accordingly, contrary to convention wisdom a coating of the devitrified BMG may be used as a coating in certain applications, and these crystalline coatings can be used to make a softer metal having the hardness of BMG (or harder), thus improving wear resistance and allowing for higher temperatures to be used.
Note that this technique can further take advantage of the fact that certain metallic glass alloys, especially bulk metallic glasses, have excellent wetting characteristics. For example, many bulk metallic glasses have excellent wetting characteristics with respect to aluminum, titanium, steel, cobalt, graphite, quartz and silicon-carbide. Accordingly, in many embodiments of the invention, the object that is the subject of the application of the liquid phase metallic glass includes one of: aluminum, titanium, steel, cobalt, graphite, quartz, silicon-carbide, and mixtures thereof. Because the viscosity of the alloy in the liquid state will be high even if the coating is de-vitrified, the thickness and wetting angle of the coating will be similar to a fully amorphous layer. Accordingly, the appearance of a de-vitrified will be similar to an amorphous coating in thin layers so the part will look like it is made from metallic glass but does not require the high cooling rate.
The above description is meant to be illustrative and not meant to be a comprehensive definition of the scope of invention. In general, as can be inferred from the above discussion, the above-mentioned concepts can be implemented in a variety of arrangements in accordance with embodiments of the invention. Accordingly, although the present invention has been described in certain specific aspects, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that the present invention may be practiced otherwise than specifically described. Thus, embodiments of the present invention should be considered in all respects as illustrative and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The description will be more fully understood with reference to the following figures and data graphs, which are presented as exemplary embodiments of the invention and should not be construed as a complete recitation of the scope of the invention, wherein:
FIG. 1
illustrates an exemplary TTT curve for a metallic glass-based material.
FIG. 2A
illustrates a process for forming a layer of metallic glass in accordance with embodiments of the invention.
FIGS. 2B and 2C
2
2
illustrate exemplary TTT curves for: (B) moderate, and (C) poor glass forming metallic glass-based materials, in accordance with embodiments of the invention.
FIG. 3A
illustrates a process for forming a layer of metallic glass in accordance with embodiments of the invention.
FIG. 3B
illustrates an exemplary TTT curve for a good glass forming metallic glass-based material, in accordance with embodiments of the invention.
FIGS. 4A and 4B
illustrate how a coating layer of metallic glass can be developed to mask a rough object surface in accordance with embodiments of the invention.
FIG. 5
illustrates dipping an object in a bath of liquid phase metallic glass to develop a layer of metallic glass on the object in accordance with embodiments of the invention
FIGS. 6A to 6C
illustrate spinning an object having a coating layer of liquid phase metallic glass to facilitate the wetting of the object and to eliminate excess liquid in accordance with embodiments of the invention.
FIG. 7
illustrates dipping an object in a bath of liquid phase metallic glass within and inert atmosphere to develop a layer of metallic glass on the object in accordance with embodiments of the invention
FIG. 8
illustrates pouring liquid phase metallic glass over an object to develop a layer of metallic glass on the object in accordance with embodiments of the invention.
FIG. 9
illustrates coating a cell phone casing with a layer of metallic glass in accordance with embodiments of the invention.
FIG. 10
illustrates spraying the inside of a piping with a layer of liquid phase metallic glass in accordance with embodiments of the invention.
FIGS. 11A and 11B
illustrate fabricating a layer of metallic glass by pouring liquid phase metallic glass over a substrate, cooling the liquid phase metallic glass, and separating the solidified metallic glass from the substrate.
FIG. 12
illustrates using a rolling wheel to help form a liquid phase layer of metallic glass that has been poured on a substrate in accordance with embodiments of the invention.
FIG. 13
provides the Ti—Be binary phase diagram showing a very deep eutectic temperature at 30 atomic % Be.
FIG. 14
provides DSC curves showing traces from a BMG and three BMG composites, each having a liquidus temperature of below ˜770° C., in accordance with embodiments of the invention.
FIG. 15
provides Xray data plots showing: (Left) a fully amorphous x-ray scan showing no crystalline Bragg peaks, indicating a glass, (Center) the same alloy cooled slightly slower with at least one crystalline peak, indicating that the alloy is partially crystalline, and (Right) the alloy has cooled so slowly that it is now fully crystalline in accordance with embodiments of the invention.
FIG. 16
provides a table of properties of exemplary amorphous (A), crystalline (X), and composite (C) metallic glass-based materials in accordance with embodiments of the invention.
FIG. 17
provides data from a hardness measurement for an exemplary metallic-glass based material in glass and crystalline form, in accordance with embodiments, in comparison with a Ti-6-4 material. | |
In this paper, we define and operationalise three modes of research engagement using qualitative secondary analysis (QSA). We characterise these forms of engagement as continuous, collective and configurative. Continuous QSA involves modes of engagement that centre on asking new questions of existing datasets to (re)apprehend empirical evidence, and develop continuous (or contiguous) samples in ways that principally leverage epistemic distance. Collective QSA characteristically involves generating dialogue between members of different research teams to establish comparisons and linkages across studies, and formulate new analytic directions harnessing relational distance. Configurative QSA refers to how existing data are brought into conversation with broader sources of theory and evidence, typically in ways which exploit greater temporal distance. In relation to each mode of engagement we discuss how processes of both (re)contextualisation and (re)connection offer opportunities for new analytical engagement through different combinations and degrees of proximity to, and distance from, the formative contexts of data production. | https://eprints.whiterose.ac.uk/174006/ |
We believe that it is always the research objective or the purpose of the education programme that defines the preferences, and thus, any required and available technology (framework, media editing tool, etc.) can be used in our research.
- All our instructional materials are experimental:
- As the core activities of ALUMNUS ID Lab focus on research & development & innovation, our instructional materials are primarily developed for answering research questions and/or for the implementation of empirical experiments. ALUMNUS ID Lab does not develop instructional materials for individual orders, except for tailor-made requests for specific research purposes; therefore, all our instructional materials are experimental and serve research and development objectives (even in cases they do not seem so).
- All our experimental materials are in compliance with the relevant quality assurance guidelines. We only share instructional materials that are suitable for learning purposes and present no hazard to their users. There might be some learning materials and/or courses that could indeed be better (with more impressive multimedia content, better structure, etc.); these are “faulty” because the research requires these deficiencies.
- Some learning materials and courses are available with the same content but with different designs, because the research behind
them is based on control group comparative experiments. In these cases, despite the differences, all of the available materials are suitable for learning purposes, and we try to support the users’ choice with practical recommendations.
- e-learning development aims to develop instructional materials. The process starts with the definition of the educational objectives and ends with the measurement of the objective-related learning effectiveness or the follow-up of the learning performance; either way, the development process should always go beyond simple media editing. In some cases, we offer not only courses, but complete educational programmes; these are the products of our educational programme development experiments.
- The developed materials can be significantly different in terms of their educational objectives, contents, target groups and size, because we provide research opportunities for non-conventional developments as well; thus the sometimes strange topics, unusual target groups or exceptional (creative) course development solutions.
- In accordance with the relevant research in the background, we provide our e-learning materials in Hungarian or in English language. | http://alumnus.hu/index.php/development/ |
Kevin Spacey (actor, Director, Producer, and Screenwriter), born on July 26, 1959 in South Orange, USA. Kevin Spacey's age 59 years & Zodiac Sign Leo, nationality American (by birth) & Race/Ethnicity is White. Let's check, How Tall is Kevin Spacey?
Kevin Spacey Bio
Kevin Spacey Height
5 ft 9 in (175 cm)
|Height & Weight|
|Height (in Feet-Inches)||5 ft 9 in|
|Height (in Centimeters)||175 cm|
|Weight (in Kilograms)||74 kg|
|Weight (in Pounds)||163 lbs|
Kevin Spacey Body Measurements
Kevin Spacey's full body measurements are . | https://famousbodysize.com/kevin-spacey/ |
From the Multnomah Lawyer: The Corner Office | Professionalism November 2019
Today’s discussion is about the receipt of inadvertently sent documents and, in particular, whether a professional lawyer may simply “send them back” as so many of us were instructed by our mentors to do. The typical scenario at hand involves privileged material being produced by the opposing attorney in discovery. Even recalling their mentor’s advice, an ethical lawyer should recognize this situation as complex and approach it with candor both to client and to opposing counsel.
The ethical rule that governs this situation is the picture of simplicity: A lawyer receiving an inadvertently sent document shall notify the sender. Oregon RPC 4.4(b). Formal opinion 2005-150 (OSB 2015 rev) confirms that, so long as the document is inadvertently sent, the recipient’s ethical duty under this particular rule begins and ends with the providing of notice. But see formal op 2011- 186 (OSB 2015 rev) (regarding documents sent without authority). Larger questions about what the receiving lawyer might and might not do with an inadvertently sent document have been left to the application of other ethical rules, to laws outside the RPCs and to concepts of professionalism.
Rule 4.4(b) reassures the reader without elaborating the complexities that arise from other ethical rules that require adherence to court orders and rules, which may impose very different and more sweeping obligations than does 4.4(b) itself. Under the MBA Commitment to Professionalism, our obligations include “support[ing] the effectiveness and efficiency of the legal system” and “seeking to resolve matters with a minimum of legal expense to all involved.” In view of the legal battle that may follow our decision to try to use the accidentally sent materials, a client may be well advised to follow the time-honored rule passed down by our elders.
And therein lies the key. This decision - what to do with inadvertently sent documents - may lie with the client and not with counsel. Recall that clients decide the objectives of representation, and their lawyers decide the means (Oregon RPC 1.2). If the contents of the documents are of a nature that they might change the objectives of the representation, then the decision of what to do with them, by all rights, belongs to the client. But, if the document is subject to a protective order, your ability even to describe it to the client may be limited.
And so, a protocol emerges. First, read the local, state-level and federal rules that apply to your case, as well as any applicable protective or other court orders. Be sure you are following them all. Second, call your opposing counsel. Tell them you have received what appears to be an inadvertently sent document and offer to send them a copy. Confirm that they understand the complexities: that you have given them their 4.4(b) notice, that the responsibility to take action lies with them and not with you, but that you are doing what you can to limit both parties’ legal costs in the meantime. Try to determine whether they are notifying their insurance carrier; your client won’t have insurance coverage for this.
Finally, call your client. Confirm this conversation and get confirmation in writing from them as you deem necessary or appropriate. Discuss the situation with candor, which I always find is my best friend in these types of circumstances. Tell them it may be possible to use this document (if that’s your judgment), but the cost may be very high both in terms of expense and in terms of lost credibility with the court and with the other side. Tell them that there may be an insurance company covering the other side’s fees. If the document is relatively meaningless, explain that to them and tell them that it’s your decision what to do and you’re sending the document back.
If the document really is one that potentially changes the objectives of representation, then let the client make the decision, as it is their right to do. But advise them - if you think it’s true - that the battle is not worth waging in terms of the damage it will do to relationships, and an uncertain outcome. And advise them - again, if it’s true – that their decision may lead to the need to find a new lawyer if you can’t go forward. It’s a good time to remind your client and yourself that you don’t have to continue representation of a client whose choices embarrass you or make you uncomfortable.
The Corner Office is a recurring feature of the Multnomah Lawyer and is intended to promote the discussion of professionalism taking place among lawyers in our community and elsewhere. While The Corner Office cannot promise to answer every question submitted, its intent is to respond to questions that raise interesting professionalism concerns and issues. Please send your questions to [email protected] and indicate that you would like The Corner Office to answer your question. Questions may be submitted anonymously. | https://mbabar.org/about/mba-news/from-the-multnomah-lawyer--the-corner-office-professionalism-november-2019/ |
The response among lawyers and judges to the professionalism movement in Georgia has been overwhelmingly positive. Some of those who were at first skeptical have come forth, such as the Emory Law School professor who confessed: "At first, I thought all this professionalism business was just fluff; but now that I've seen the enthusiasm and heard the questions that students bring into the classroom from the Orientations on Professionalism, I'm a convert. We are being challenged to talk about professionalism in the practice of law." The Commission has found that the lawyers and judges in Georgia are eager to talk about professionalism issues, to explore ways of handling professionalism and ethical dilemmas that occur in the practice of law, to voice their concerns about the practice of law and the administration of justice - if they see results from these efforts. Results can take the form of strategies for dealing with a "win at all costs" attitude in opposing counsel and improving client relations skills, state bar programs to assist lawyers in the everyday practice of law, transition programs from law school to practice. In written and oral evaluations of the professionalism effort, the Commission has received responses such as:
"The heightened awareness of professionalism that exists today among the members of the State Bar is often taken for granted. Ten years ago this was not the case."
Georgia Lawyer
"A dozen years ago, we never talked about professionalism. Now we talk about it all the time."
Federal District Judge
"Any time lawyers can get together and discuss professionalism, it refocuses my practice from a professionalism standpoint."
Participant at CLE seminar
"Increase the Professionalism CLE requirement to 2 hours each year, and make one of them a meeting like this one."
Participant at Town Hall Meeting
"I like your program. We all need to be supportive of it."
Georgia Appellate Judge
"All lawyers should know that this [professionalism] is a high priority item even in earliest legal training."
Georgia Appellate Judge
"These kinds of programs allow us to test what's acceptable without risks. We learn what other lawyers think about the resolution of a dilemma and talk about it."
Participant at ICLE Seminar
"The program helped me to better deal with clients. Continue to do the good work."
Participant at Georgia Association of Criminal Defense Lawyers Seminar
"Justice Kennedy began program on inspirational role - that's why I come to Convocations - to be inspired about my role and work as a lawyer - and I left a more committed one."
Participant at Convocation on Professionalism
"I appreciate all of the good work that is being done in this area. It is important that all of us work to make sure that those who are entering the practice of law are aware of how strongly many of us feel about what lack of professionalism is doing to our profession. If I can be of any assistance to you, please let me know."
Superior Court Judge
"The main thing about this program was that it gave us a focus of how we should act, how we should be - not crass, cold lawyers out to make money -- we should be professional, ethical, and moral. To me, all three go hand in hand. By doing this during orientation, it sends the right message."
Student at Law School Orientation on Professionalism
"Your Commission really is important so congratulations on all of your efforts and that of members of the Commission."
Letter from Georgia Lawyer
"[I]t was clear to me that the orientation program . . . had a significant effect on the students. I observed a sense of relief among the students in learning that the duties of an advocate do not require lawyers to leave their personal values at the courthouse door."
Lawyer Leader at Law School Orientation on Professionalism
"Your work is important, and if ever I can help, let me know."
Senior Federal District Judge
"Participation in the discussion groups is a real learning experience. Reinforces the importance of values in law practice."
Lawyer Leader at Law School Orientation on Professionalism
"I was impressed by the sincerity of your mission. You have certainly helped me to recognize that there are forces at work within the legal profession attempting to address the concerns of businessmen . . . . I would like very much to continue the dialogue with the profession through your commission."
Chairman and CEO of an Atlanta company
"Very valuable program. Good to see interaction of academic (law faculty) and practice (attorney) - important to our common goal."
Faculty Leader at Law School Orientation on Professionalism
"The format allowed me to share and learn from others with different points of view." | https://www.gabar.org/aboutthebar/lawrelatedorganizations/cjcp/response-to-georgia-professionalism-effort.cfm |
This website (and associated documents) is for informational purposes only. It is not a prospectus. It does not constitute a legal contract or offer information beyond the scope such as tax advice or partnership documents. This document does not constitute an offer to sell or solicitation of an offer to buy any security. Neither may this document nor any of the proprietary information herein be published, reproduced, copied, disclosed, or used for any purposes without the consent of Jonathan Kerr on behalf of Storyteller.IM, LLC. This is in accordance with the SEC. The memorandum has been prepared in regards to the MOVIE film projects that have been listed on this website. While the information herein is believed to be accurate, the Managers disclaim any and all liability for representatives or warranties expressed or implied, contained in, or for omissions from, this memorandum or any other written or oral information provided or made available by the managers. Estimates, projections, and distribution contained herein shall not be relied upon as a promise or representation as to future results. This document does not purport to contain all the information that an interested party may desire. In all cases, interested parties should conduct their own investigation, analysis, and evaluation of the Project, the terms of the equity interests to be issued thereby, including the merits and risks of an investment in such equity interests, and the data set forth in this Presentation. This memorandum is intended solely for the persons receiving it in connection with this offering and is not authorized for any reproduction or distribution to others whatsoever. The memorandum and other information provided to the person receiving this memorandum shall be disclosed to only such employees, agents, or other representation of the recipient who shall reasonably need to know the same in connection with their evaluation of an investment in the company. All copies of the memorandum and any other information given to person receiving the memorandum shall be returned to the Company upon request if the transaction with the company is not consummated. The information contained herein is proprietary, nonpublic information, which may not be used for other than the purpose of evaluating this offering and must be kept strictly confidential. The recipient of this memorandum acknowledges compliance with the above.
Risk Statement
Investment in the film and television industry is highly speculative and inherently risky. There can be no assurance of the economic success of any motion picture or television pilot/series since the revenues derived from the production and distribution of a motion picture and series depend primarily upon its acceptance by the public, which can not be predicted. The commercial success of a motion picture and television series also depends upon the quality and acceptance of other competing films and television shows released into the marketplace at or near the same time, general economic factors and other tangible factors, all of which can change and cannot be predicted with certainty. The entertainment industry in general and the motion picture industry and television industry in particular, are continuing to undergo significant changes, primarily due to technology developments. Although these developments have resulted in the availability of alternative and competing forms of leisure time entertainment, such technological developments have also resulted in the creation of additional revenue sources through licensing of rights to such new media, and potentially could lead to future reductions in the costs of producing and distributing motion pictures and television shows. In addition, the theatrical success of a motion picture or a television series’ success remains a crucial factor in generating revenues in other media such as videocassettes, DVD’s and many other ancillaries. Due to the rapid growth of technology, shifting consumer tastes, and the popularity and availability of other forms of entertainment, it is impossible to predict the overall effect these factors will have on the potential revenue from and profitability of feature-length motion pictures or the success and popularity of a television pilot/series.
Footnotes
1 Filmmakers is a term defined by the owner of the film property (for example, in this case of “I Am We” MOVIE project, the Filmmaker is Writer/Director, Jonathan Kerr) with the intention of embodying the people responsible for bringing the film to life.
2 Lifetime of the film indicates the duration of time while the film remains financial property of the film creator (for example, in this case of “I Am We” MOVIE project, the Filmmaker is Writer/Director, Jonathan Kerr). The expectation is that the filmmaker will retain full rights in perpetuity, but sometimes films can have their full rights and/or financial rights purchased. At times, this may be a fiscally responsible decision to ensure investors are able to be paid back. If a decision is made by the filmmaker to sell these rights, it is likely this will result in the dividend payments to the filmmakers, cast, crew, and investors being irreparably severed. | https://storyteller.im/disclaimers-and-risk-statement/ |
The genesis of Nollywood
Before the term ‘Nollywood’ was coined in the early 2000s to describe and mean the Nigerian cinema, filmmaking in the country began as early as the late 19th century. In the century that followed, improved motion picture exhibition devices made way for the first-ever feature film in Nigeria in 1926. The movie Palaver, a.k.a Palaver; A Romance of Northern Nigerian, became the first film to feature Nigerian actors in substantial roles. Its simple plot portrayed conflicts between a British District Officer and a local tin miner, escalating into a war. However, the movie has been lauded negatively by critics to be a proudly racist despite being shot in Nigeria. It is among other colonial films which claimed the beneficent influence of the white man in Africa.
A few years later, in 1957, the movie Fincho became the first Nigerian film to be shot in color. Sam Zebba directed it, and the film had the theme of colonization like the previously produced Palaver. Fincho followed the titular character’s story dealing with industrialization brought to Nigeria by European colonialists, the tension between tradition and innovation, and mechanization’s threat to traditional labor. It ran for 76 minutes and was shot with Nigerian non-professional actors and Pidgin dialogue dubbed by Nigerian students at the Los Angeles University of California.
After the country gained independence, there became an increase in Nigerian films, but soon afterward, there was a decrease, which somehow stretched into the late 90s. All this paved the way for the genesis of what would later be known and become Nollywood.
Within this period, there was some significant facet like the emergence of the video film market that saw few movies produced in video format. The 1992 horror-thriller Living in Bondage is highly credited as one of the films that made the video film era successful despite other movies being made in the same format before 1992. Living in Bondage was directed by Chris Obi Rapu and written by Kenneth Nnebue and Okechukwu Ogunjiofor. Actor Kenneth Okonkwo and Nnenna Nwabueze got their breakout roles in the movie.
With all these merits, there wasn’t a name attached or customized to the booming industry until 2002, when Canadian-American journalist Norimitsu Onishi coined the word ‘Nollywood’ in his New York Times article. He used this term to describe Nigerian movies and use it to gain popularity outside of the continent. However, the purpose of the term worked and stuck, thereby becoming a tagline for the film made in the country. Like the movie industry in Los Angeles, US, is tagged as Hollywood, and that of Mumbai [Bombay], India, is tagged as Bollywood.
Related articles:
– Five Nollywood actresses starring in lead roles in major 2022 movies
– Top 7 most controversial Oscars moments [watch videos]
– 21 Scariest Asian Horror Movies To Watch.
The inception of new Nigerian cinema
After the video film market era and video format film, the movie industry shifted again. The new era is often tagged as the ‘New Nigerian Cinema’ and can be said to be heavily influenced by modernization and the launch of a series of modern Cinema houses across major cities in Nigeria. The movies produced in this period had high production qualities. The themes explored in these movies shifted away from witchcraft, human rituals, and cannibalism, the usual center of attention in previously produced films.
In 2006, Nigerian filmmaker Kunle Afolayan released the Yoruba-language film Irapada. It became the first production to be screened at the Silverbird Galleria in Lagos- one of the new Nigerian cinemas that launched in the country. Like in the prior video film era, when Living in Bondage was believed to have spearheaded the success of that era, another Kunle Afolayan movie, The Figurine, was considered a; game-changer. It heightened the media attention toward the ‘New Nigerian Cinema.’ While all these development were ongoing, it is also worth mentioning that the stance where the sub-industries under Nollywood was.
The sub-industries of Nollywood
Nollywood in Nigeria is divided mainly into regional and marginally ethnic and religious lines. This allows for the existence of distinct industries. Each of these sub-industry portrays a particular section and ethnicity. Generally, there is the overall English-language film industry where some actors and filmmakers crossover into the sub-industry.
For instance, the Yoruba-language cinema is a sub-industry of Nollywood, with most of its practitioners in the western region of Nigeria. Some of its predecessors are Ola Balogun, Duro Ladipo, Adeyemi Afolayan, Hubert Ogunde, and Moses Olaiya.
The Hausa-Language Cinema is informally referred to as ‘Kannywood.’ it is based in the northern city of Kano and goes as far as way back as the 90s. The Hausa language cinema slowly evolved from the productions of RTV Kaduna and Radio Kaduna in the 1960s. The Hausa cinema has veterans like Dalhatu Bawa and Kasimu Yero, who pioneered drama productions that became popular with the Northern audience. In the ’70s and ’80s, Usman Baba Pategi and Mamman Ladan introduced the Hausa comedy to the Northern audience. However, in the 1990s, the Hausa Cinema saw a dramatic change; this period is usually cited as when the first commercially successful Kannywood film was produced. By 2012, the industry was recorded to have made over 2000 films, including the highly rated Milkmaid movie.
Outside of the country, the term Nollywood became incorporated with other film industries like the Ghanaian English-language cinema. This incorporation helped in introducing a bunch of Ghanaian actors into mainstream Nollywood. Names like Van Vicker, Jackie Appiah, Majid Michel, Yvonne Nelson, John Dumelo, and Nadia Buari became household personas in Nollywood. Currently, the Ghanaian language cinema has somehow ceased to continue.
More cinema success and the popularity of Netflix
Away from the sub-industries, with the critical responses that The Figurine Nigerian movies started leaning towards producing more commercially appealing films, which made room for a coalition of the term ‘highest-grossing Nigerian film.’ After The Figurine was released in 2009, several films after that took turns surpassing the success of The Figurine. These new films once again shifted in the themes they explored.
Comedies, relationships, marriages, and luxury became the subject matter that most films in the late 2000s became known for. To some extent, there were also more options and avenues for getting funds to produce these films. Some past administrations in the country played vital roles in the country’s film industry; several creative projects were launched, assisted with grants and funding to help most filmmakers meet up to their potential in filmmaking. By 2014, the Nigeria film industry was estimated to be worth 853.9 billion, making it the third most valuable movie industry in the world behind the United States and India. However, in 2016, the industry rose to a new level and became the second-largest film producer in the world. It was further credited as a significant part of the Arts, Entertainment and Recreation Sector contributing 2.3 percent (NGN239billion) to Nigeria’s Gross Domestic Product [GDP]. That same year, filmmaker Kemi Adetiba released the Nigerian romantic comedy-drama The Wedding Party. This movie became the highest-grossing Nigerian film ever. The following year, a record was broken by its sequel, The Wedding Party 2.
Alter Ego, a 2017 Nigerian drama film written by Jude Martins, directed by Moses Inwang and produced by Sidomex Universal, also stole the limelight when it was released. It stars Omotola Jalade, Wale Ojo, Jide Kosoko and Kunle Remi, and its theme was regarded as unique. (It is also avilable on Netflix)
By 2018, the popular streaming service Netflix had become a household name in Nigeria. Several Nigerian movies were being offloaded on the service to be made available for streaming. The 2018 Genevieve Nnaji directed movie Lionheart became the first Netflix original film to be produced in Nigeria. The film also marked the first-ever Nigerian movie to be submitted for the Best International Feature Film at the 2020 Academy Award, although, it later got disqualified.
As Nollywood movies continued to debut in cinemas and, later on, the streaming platform, movies critics became concerned with the patterns these films followed. Over and over, the film were always star-studded, aimed with top-notch cinematography, and failed to divert away from the same type of storyline; only a few out of the many produced films from the late 2000s to date has left a positive impression on audiences and film critics.
Kemi Adetiba struck again in 2018 with the release of the crime political thriller flick King of Boys; the movie was a hit in cinema and explored a different story that became critics’ and movie lovers’ favorite. In King of Boys, a powerful, successful, and philanthropist matriarch with political ambition struggles for power. The movie starred veteran actresses Sola Sobowale in the lead role and it is already being touted as one of the few films that redefined female characters in Nollywood.
Typically early Nollywood films since the video film era adopted a stereotypical portrayal of female characters- women in movies were presented as materialistic, weak, forgiving, and submissive. Though some films showed women as brutal, dominating, and powerful, these films always ended with such characters meeting a fateful end; either she dies or is forced to convert into a modest nature. But with the character of Sola Sobowale, a.k.a Alhaja Eniola Salami, the narrative of women not being able ‘to eat their cake and have it’ is reconstructed. King of Boys portrayed a female character in a new light. At the time of the movie’s debut, it went ahead to have the highest opening week in 2018 for a non-comedy film. The political thriller is also one of the few movies to debut later on Netflix when streaming became mainstream in the country.
Nollywood’s influence on Social Media
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In addition to the growing presence of social media, then came the need to document and revisit the earlier days of Nollywood. While the production of films during the early 2000s was so conventional, the somewhat low-quality aesthetic mannerism became memes- a digital method of expression. These memes are inspired mainly by the 2003 comedy film Aki an Ukwa, also informally referred to as Aki and Pawpaw. The younger generation (Gen-Z) has created a sub-culture out of Nollywood in terms of documentation. Music and, most importantly, fashion inspirations are being drawn from the early Nollywood films. The Instagram account, nolly.babes, is an archive for all things unconventionally in terms of memes and the early period of Nollywood ideology.
The launch of Netflix Naija
In 2020 Netflix officially launched in Nigeria with ‘Netflix Naija,’ a term describing its presence in the country. The official launch of the giant streaming platform saw Nigerian filmmakers acquiring movie contracts to produce movies for the streaming platform exclusively. Filmmakers like Mo Abudu, Kemi Adetiba, and Kunle Afolayan are among some personas who have debuted movie projects exclusively for Netflix.
In 2021 Kemi Adetiba landed a sequel to her 2018 thriller success King of Boys into a limited series titled- The Return of the King, making it the first limited Nigerian series on the platform. In the same vein, Mo Abudu is set to launch another limited series with Netflix titled Blood Sisters, scheduled to premiere in May 2022.
Alternative storytelling in Nollywood
Away from the mainstream set of filmmakers, other filmmakers like C.J Obasi, Abba Makama, and recently Damilola Orimogunje, have created movies that also stand out.
C.J Obasi’s first attempt was in 2014 with the Zombie thriller Ojuju. A zero-budget movie that critics lauded for its production. Although it lacked big-money backing, it somehow was able to pass across the supposed message it carries while also surpassing expectations.
In 2019, Abba Makama tapped into indigenous tradition to create The Lost Okoroshi – stories like this are not familiar within mainstream Nollywood.
Another Indie film producer, Damilola Orimogunje, explored an atypical theme in the drama For Maria; Ebun Pataki (2020). The drama offers a lens into the post-life of a mother who just experienced childbirth and is going through postpartum depression.
An anthology movie by C.J Obasi, Abba Makama, and Michael Omonua Juju Stories, heavily inspired by Nigerian folklore and urban legend, is also among the few films rooted in alternative-mainstream storytelling.
The remake of old movies
With the upgrade of high-quality production, some film producers have gone back in time to channel ideas into remaking old movies. The first remake of an old Nollywood movie was in 2019; four years after filmmaker Charles Okpaleke acquired the 1992 horror flick Living in Bondage rights for ten years under his production company.
Living in Bondage; Breaking Free, a sequel to the first film, debuted to positive reviews from movie critics. The movie received 11 nominations at the 2020 Africa Magic Viewers Choice Awards and won in 7 categories. Charles Okpaleke again obtained another right to remake Amaka Igwe’s 1995 action film Rattlesnake in that same year. The new remake was titled Rattlesnake; The Ahanna Story and was directed by Ramsey Nouah, who also directed the remake of Living in Bondage. It was released in 2020.
Again Charles Okpaleke remade the 1994 horror drama film Nneka the Pretty Serpent in 2020. The latest remake of an old Nollywood classic film is the 2004 comedy film, Aki an Ukwa, informally referred to as Aki and PawPaw. The remake was released in 2021, directed by Biodun Stephen. It sees actors Chinedu Ikedieze and Osita Iheme reprising their roles as Aki and PawPaw eighteen years later after the first was released.
Other old films like the 1994 two-part movie Glamour Girls, about independent single women starting on their paths within Nigeria’s traditionally patriarchal society, is also in the works for a remake.
Top 10 highest grossing Nigerian movies (updated last: April 2022)
10- Your Excellency, directed by Funke Akindele – 2019
9- Merry Men 2; Another Mission, directed by Moses Inwang – 2019
8- Merry Men; The Real Yoruba Demons, directed by Toka Mcbaror – 2018
7- King of Boys, directed by Kemi Adetiba – 2018
6- Christmas in Miami, directed by Robert Peters – 2021
5- Sugar Rush, directed by Kayode Kasum – 2019
4- Chief Daddy, directed by Niyi Akinmolayan – 2018
3- The Wedding Party 2, directed by Niyi Akinmolayan – 2017
2- The Wedding Party, directed by Kemi Adetiba – 2016
1- Omo Ghetto; The Saga, directed by Funke Akindele – 2020
You may also like to read our latest article: Read this before taking a dog home! Dogs breeds with the most health problems. | https://sidomexentertainment.com/latest-news/entertainment-news/movies/nollywood-naija-movies/ |
In a time when comprehensive studies have shown that instructor-student interaction is at the essence of an effective education methodology, defending traditional instruction — the prototypical education without interaction method — may seem irrational. However, we should not disregard traditional instruction in its entirety, particularly because this is a method under which a significant number of students feel most comfortable. Usually these are students who like to use the lectures as a guide and base their learning on independent study. (I was one of them.) But even for those students, lecturing can be made much more productive if interactive learning tools are included in the equation. Indeed, this is one of the solutions that we have developed over the last few years in the Physics Department, in parallel with our interaction-based instruction initiatives in order to offer UCF undergraduates the most diverse education scenario.
To be more specific, in traditional physics courses, the lab and the lecture sections are separate, and unfortunately, lectures may be given to up to 300 students at once. One can easily understand how faculty-student interaction is greatly diminished under these conditions. In addition, students often feel the lab and lecture contents are out of sync, which is unavoidable as the course advances due to calendar limitations. Scheduling all students in a lecture class into the same laboratory sections helps. But the bottom line is to make students aware of the fact that physics, like other sciences, is mainly driven by experiments and not the other way around. We have had great success in this respect at UCF. Labs are designed to be highly interactive and are supported online, so all students are prompted to work in groups during practice sessions and individually before and after their lab days. In addition, interactive tools that encourage student participation and discussion are routinely used in our lectures, definitively helping with the assimilation of the material, even in large enrollment sections.
A healthy mixture of enhanced traditional instruction and interactive-based methods may stand as a model for modern educational institutions such as UCF.
No Lectures/No Tests
After a long industrial career, I was fortunate to be hired by UCF’s Physics Department, where I have been teaching for about 10 years. When I began lecturing, I noticed that most of my students stared at me with glazed eyes. When I shared my observation with fellow faculty members, my experience wasn’t all that unusual. Physics education research has documented that the average student attending a physics lecture zones out after about 10 minutes. This is not what I would refer to as a successful process.
Enter Harvard professor Eric Mazur, who developed a successful lecture-free format for his physics course and did away with exams. This class format is used in two sections of the introductory physics course at UCF this fall. The approach requires intense student involvement utilizing learning teams, pre-reading monitoring and team-based projects.
The observation that most student learning takes place while reading a textbook suggests that the reason students may not do well in physics is that they read their textbook only when absolutely necessary, which is usually prior to an exam or a quiz. Up until now, it wasn’t possible for an instructor to verify that students were reading the material, but thanks to a program developed at MIT, it is now possible to verify the veracity with which reading is occurring. As a result, the learning is more assured, and class activity can be used to reinforce it. So, voilà, no lecture is needed!
Finally, the last component of this course format is the recognition that studying for exams produces only transient and shallow learning. So instead of exams, we use qualitative questions to analyze students’ knowledge. If a student answers incorrectly, they consult with their team and repeat the question in order to answer correctly. Most times, students are also permitted to use any reference material they wish, including the Internet. With all of the information readily available, there is no need to memorize material, and study is replaced by using the information gained in the team projects. This method mimics how engineers work on the job, giving students the opportunity to experience practical problem-solving. | https://www.ucf.edu/pegasus/put-it-to-the-test-can-physics-one-of-the-oldest-academic-disciplines-in-world-history-be-taught-with-a-modern-appraoch-to-teaching-without-lectures-and-tests/ |
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Overview: CDE's Computer Science Resource Bank contains a variety of materials for computer science educators, including standards, curricula, and materials for professional educator development as directed by H.B. 17-1884, Modern Technology Education in Public Schools.
Questions? Please contact Chris Summers, Computer Science Content Specialist, with any questions.
Everyone Can Code
We created a comprehensive Everyone Can Code curriculum to help you teach coding to students from kindergarten to college. With teacher guides and lessons, you can introduce the basics on iPad, then advance to building real apps on Mac. So whether your students are first-time coders or aspiring app developers, you’ll have all the tools you need to teach coding in your classroom. We even offer App Development with Swift Certification for students who have completed App Development with Swift.
Type of Resource:
- Curriculum
Topic:
- Apps
- Computer Systems and Networks
- Creativity
- Data Structures
- Programming
- Sequence
- Variables
Grade:
Free Resource! | http://cde.state.co.us/computerscience/computer-science-resource-bank/detail/Everyone%20Can%20Code |
Catering Manager, handles all aspects of the day-to-day work. This job entails everything from interacting with clients, to preparing menus, to overseeing the presentation and serving of the food. They oversee the preparation of the food, and at various function sites, where they ensure that food service is provided to the customer’s satisfaction.
Duties and Responsibilities
Handle Employee Issues and Training
Provide Customer Service
Plan Menus and Order Supplies
Ensure Compliance with Regulations
Core skills: | https://www.vip-staffing.com/job-listings/catering-supervisor/ |
Today, most of the water on Mars is firmly hidden in its polar ice caps, but once in abundance on this planet, new research suggests that overflowing lakes may have carved the planet's dramatic canyons.
As Phys.org According to reports, billions of years ago the water would have spurted through huge rivers on Mars that emptied into craters that eventually became vast seas and lakes.
Now, new research conducted by the University of Texas at Austin has evidences that sometimes these crater lakes have become so full of water that swollen lakes have overflowed from their basins, which would have created floods that were large enough that finished. creating canyons of the planet. In fact, it is even believed that some of these floods on Mars would have been of such intensity that canyons may have been formed in just a few weeks.
The lead author of the new study, Tim Goudge, who is a postdoctoral researcher at UT Jackson's School of Geosciences, explained that his new research reveals that geological activities such as flooding may have had a much greater impact than plate tectonics now see on Mars today.
"These broken lakes are quite common and some of them are quite large, some as large as the Caspian Sea. So we found that this style of catastrophic flooding and rapid incision of exit canyons was probably very important on the surface of Mars. "
Overflowing crater lakes carved canyons across Mars @utaustin https://t.co/diDcwZtLTS
– Phys.org (@physorg_com) November 16, 2018
Scientists already know that many of Mars' craters have already been filled with water and turned into paleolagos. More than 200 of these paleolagos were seen alongside ravines that sometimes extend for hundreds of miles, but before this new research scientists were unable to determine whether these canyons were formed rapidly or for long periods of time, which could last millions. years.
When looking at the photographs of NASA's Mars Reconnaissance Orbiter satellite, researchers carefully analyzed the topography of 24 paleolakes, crater edges and their exits, and found evidence of flooding here. In fact, one of the paleolagos studied was the Jezero Crater, which is currently being considered as a possible landing site for the Mars 2020 probe.
As Goudge remarked, "This tells us that things that are different between planets are not as important as the basic physics of the overflow process and the size of the basin. You can learn more about this process by comparing different planets instead of just thinking about what is happening on Earth or what is happening on Mars. "
The new study, which describes how Mars canyons were probably formed by overflowing lakes, was published in Geology. | https://afaae.com/argentina/new-research-reveals-that-overflowing-lakes-on-mars-may-have-carved-out-the-planets-dramatic-canyons/ |
The annual large and deep ozone hole developing over the Antarctic is in no way backing down in the month of November, according to the US National Oceanic and Atmospheric Administration (NOAA) and NASA scientists.
“Persistent cold temperatures and strong circumpolar winds” had helped in the formation of the Antarctic ozone hole, that reached its peak in September, and it will in most probable scenario persist into November. Scientists said that the ozone hole that appeared in 2020 will be the twelfth-largest ozone hole in the 40 years of satellite recorded estimates. As per the data collected from the balloon-borne instrumental measurements, this year also saw the 14th lowest ozone readings in 33 years.
The Arctic ozone hole as of March 2020. Image: NASA
The statement also added that the hole had reached its climax on 20 September when the size of the vacuum in the earth’s atmosphere spread to a region measuring 24.8 million square kilometers, which is roughly three times the area of the continental United States. The Ozone layer in the stratosphere of our planet acts like a protective layering to shield us and other worldly beings from the harmful UV rays. Without the ozone screen in place, there is no barrier for the ultraviolet radiation to reach us.
Ozone is formed of three Oxygen atoms and reacts with chemicals very easily. There are many ozone depleting substances (ODS) in the atmosphere that led to the formation of the ozone hole in the first place. The Montreal Protocol on Substances that Deplete the Ozone Layer was signed by several nations to regulate the production and consumption of about 100 of these ODS or man-made chemicals. According to NOAA, actions taken under the Montreal Protocol “prevented the hole from being as large as it would have been 20 years ago”.
Paul A Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center, said that the hole would have been a million square miles (approx. 25 lakh square kilometres) if there was still as much chlorine in the stratosphere as there was in 2000. | |
Short Bio: Mirella Lapata is professor of natural language processing in the School of Informatics at the University of Edinburgh. Her research focuses on getting computers to understand, reason with, and generate. She is as an associate editor of the Journal of Artificial Intelligence Research and has served on the editorial boards of Transactions of the ACL and Computational Linguistics. She was the first recipient of the Karen Sparck Jones award of the British Computer Society, recognizing key contributions to NLP and information retrieval. She received two EMNLP best paper awards and currently holds a prestigious Consolidator Grant from the European Research Council.
Abstract: TBD
◆ Jianfeng Gao, Partner Research Manager at Microsoft AI and Research, Redmond
Keynote Topic: TBD
Short Bio: Jianfeng Gao is Partner Research Manager at Microsoft AI and Research, Redmond. He works on deep learning for text and image processing and leads the development of AI systems for machine reading comprehension (MRC), question answering (QA), dialogue, and business applications. From 2006 to 2014, he was Principal Researcher at Natural Language Processing Group at Microsoft Research, Redmond, where he worked on Web search, query understanding and reformulation, ads prediction, and statistical machine translation. From 2005 to 2006, he was a Research Lead in Natural Interactive Services Division at Microsoft, where he worked on Project X, an effort of developing natural user interface for Windows. From 2000 to 2005, he was Research Lead in Natural Language Computing Group at Microsoft Research Asia, where he and his colleagues developed the first Chinese speech recognition system released with Microsoft Office, the Chinese/Japanese Input Method Editors (IME) which were the leading products in the market, and the natural language platform for Microsoft Windows.
Abstract: TBD
◆ Noah Smith, Associate Professor, Paul G. Allen School of Computer Science & Engineering at the University of Washington
Keynote Topic: Squashing Computational Linguistics
Short Bio: Noah Smith is an Associate Professor in the Paul G. Allen School of Computer Science & Engineering at the University of Washington. Previously, he was an Associate Professor of Language Technologies and Machine Learning in the School of Computer Science at Carnegie Mellon University. He received his Ph.D. in Computer Science from Johns Hopkins University in 2006 and his B.S. in Computer Science and B.A. in Linguistics from the University of Maryland in 2001. His research interests include statistical natural language processing, especially unsupervised methods, machine learning, and applications of natural language processing. His book, Linguistic Structure Prediction, covers many of these topics. He has served on the editorial board of the journals Computational Linguistics (2009–2011), Journal of Artificial Intelligence Research (2011–present), and Transactions of the Association for Computational Linguistics (2012–present), as the secretary-treasurer of SIGDAT (2012–2015), and as program co-chair of ACL 2016. Alumni of his research group, Noah's ARK, are international leaders in NLP in academia and industry. Smith's work has been recognized with a UW Innovation award (2016–2018), a Finmeccanica career development chair at CMU (2011–2014), an NSF CAREER award (2011–2016), a Hertz Foundation graduate fellowship (2001–2006), numerous best paper nominations and awards, and coverage by NPR, BBC, CBC, New York Times, Washington Post, and Time.
Abstract: The computational linguistics and natural language processing community is experiencing an episode of deep fascination with representation learning. Like many other presenters at this conference, I will describe new ways to use representation learning in models of natural language. Noting that a data-driven model always assumes a theory (not necessarily a good one), I will argue for the benefits of language-appropriate inductive bias for representation-learning-infused models of language. Such bias often comes in the form of assumptions baked into a model, constraints on an inference algorithm, or linguistic analysis applied to data. Indeed, many decades of research in linguistics (including computational linguistics) put our community in a strong position to identify promising inductive biases. The new models, in turn, may allow us to explore previously unavailable forms of bias, and to produce findings of interest to linguistics. I will focus on new models of documents and of sentential semantic structures, and I will emphasize abstract, reusable components and their assumptions rather than applications.
◆ Hua Wu, Baidu
Keynote Topic:
Short Bio:
Abstract: | http://tcci.ccf.org.cn/conference/2017/keynotes.php |
Description: Partners using D2L as their Learning Management System have a lot of options for the creation of assignments and rubrics, so the intention of this guide is to share information about which types of rubrics, assignments, and scoring processes work best with the AEFIS integration for collection of assessment data and student artifacts.
Applicable to: D2L administrators and instructors – to implement these items integration with D2L needs to be completed by the campus D2L Administrator.
Which Assessments/Assignments in D2L integrate with AEFIS?
- Assignments created under Assessments>Assignments in D2L Courses integrate with AEFIS
- At this time, AEFIS Does not integrate with:
- Quizzes**
- Self Assessment
- Discussions
- Surveys
**Quiz final score integration is expected to be available in Fall 2021.
How do I set up a D2L rubric to work with the AEFIS integration?
Rubrics can be created in the Rubrics manager in D2L Brightspace and brought into an Assignment, or the Rubrics can be created directly in the Assignment while you are building it. The rubrics MUST be Assignment rubrics to integrate with AEFIS.
D2L Rubric Requirements
- The rubric criteria levels MUST have point values
- The rubric must be Analytic when selecting Type
- The rubric does not have to be the default scoring rubric to transfer data to AEFIS
D2L Rubric Recommendations
- We recommend adding descriptive text to each Rubric Criterion level rather than leaving them displayed as Criterion 1, Criterion 2 etc, as the level labels are what display in the AEFIS User Interface. See below:
- We recommend using the Custom Points setting when setting up your rubrics to optimize the integration
Can I use a holistic rubric in D2L?
Technically yes, but not using the D2L Holistic rubric type. D2L rubrics offer an option to obfuscate the display of rubric points to students. So instead of choosing Holistic as your Rubric type when building your rubric, you may create an Analytic rubric, and select the Hide Scores from Students option under Score Visibility for that Rubric:
Can I connect a D2L Grade Item directly to AEFIS without an associated Assignment/Assignment folder?
No. At this time D2L does not offer an API endpoint to external vendors that allow data to pass from Grade Items that are not associated with an Assignment or Quiz. If you create a grade item directly within the Manage Grades screen, without an associated Assignment, the AEFIS integration can not access that data.
Can the AEFIS integration pull data from Discussion Board scores?
No. At this time, Discussion Board scoring has to take place exclusively in a Grade Item, and at this time D2L does not offer an API endpoint to external vendors that allows data to pass from Grade Items that are not associated with an Assignment or Quiz.
What types of student submissions/artifacts can the AEFIS Integration download from D2L?
AEFIS can download submissions made directly into D2L by students, as long as that D2L Assignment is linked to an outcome in AEFIS. This will allow you to identify samples of student work representing different levels of outcome achievement to support accreditation and continuous improvement efforts.
AEFIS supports the download of the following file types:
- Word
- Excel
- Powerpoint
- Image files such as .GIF and .JPG
- Video files such as .mov and .mp4
- Audio files such as .mp3
AEFIS can not download/import the following:
- Discussion board posts or text box answers/responses to Assignment prompts. There must be a file associated with the student submission/work to import that data/artifact to your system. | https://www.aefisacademy.org/resources/faq-how-to-optimize-assignments-and-rubrics-in-d2l-brightspace-for-assessment-in-aefis/ |
Assessing effectiveness of remote learning
In our classrooms, we determine our students’ needs by assessing students periodically throughout our lessons. In this special period of remote learning, teachers don’t have the luxury of pausing a lesson and revising it in real time. But there are ways we can be creative when it comes to checking for understanding and cumulatively assessing our students’ knowledge.
In my first remote lesson, my middle school students were a tad overzealous — or maybe just overwhelmed — and dived headfirst into the assignment, skipping the PowerPoint I had tried to make interesting for them. So I went back to the drawing board.
One way I found to break the habit of rushing through a digital assignment is to compartmentalize lessons by using Google Forms. You are able to create “sections” within a digital assignment. In that way, you can create tiered assignments, where your students can’t move forward without completing the previous part. You can also include sections of material so that, for example, they are only watching a segment of the presentation before answering questions, instead of flying through the entire thing.
Paired work is great to help meet the mixed needs of your students. After assigning pairs or groups, ask your students to read an article or watch a video independently. The assessment is that they each have to generate questions on their own and then answer their partner’s questions. Assessing the depth of questions each student develops is a great way to determine their level of understanding.
Whether teaching remotely or in person, the final assessment is always the biggest challenge. What better time than this era of distance learning to offer students an alternative project to a standard exam?
Creative assessments will provide you with more insight into your students’ areas of difficulty and will also provide a platform for individualized expression, deeper understanding and increased self-esteem.
One method that can work for a variety of subjects is having students work backward. Provide your class with a scenario or an incorrect answer to a problem. Then ask them to: 1) explain reasons it occurred or reasons that the answer is incorrect; 2) provide examples to substantiate their answers; and finally 3) explain what should have been done to change the outcome.
This is an excellent way to evaluate a deep understanding of the topic. It touches on application of the material and challenges students to not only think forward but to problem-solve. It also requires that they extrapolate and justify their responses.
Mini-presentations are another favorite of mine because the table is turned and the students become the experts. Have your classes create an elevator pitch or a Public Service Announcement related to the topic or event you covered. Then have them post their projects on your digital platform and ask your students to challenge one another with questions. Perhaps each student is required to post one unique question per project. This holds the rest of the class accountable for viewing one another’s work and also further tests individuals on their breadth of understanding.
Last but not least, don’t be afraid to simply check in with your students to find out how they’re really doing. At the end of the day, we’re here for them — to teach them, of course, but we’re also here to support them. They need that support in these frightening times.
Erin Schneider is a STEAM teacher at IS 259 in Bay Ridge, Brooklyn. | https://www.uft.org/news/teaching/teacher-teacher/assessing-effectiveness-remote-learning |
Full Fat or Low Fat?
“It is probable that the consumption of at least two servings per day of dairy foods (milk, cheese and yoghurt) is associated with reduced risk of ischemic heart disease and myocardial infarction (Grade B, Section 5.3 in Evidence Report ) .”
“It is probable that the consumption of two or more servings of dairy foods per day (milk, cheese and yoghurt) is associated with reduced risk of stroke (Grade B, Section 5.4 in Evidence Report ) [376, 377] particularly reduced fat varieties.”
376 The Survival Advantage of Milk and Dairy Consumption: an Overview of Evidence from Cohort Studies of Vascular Diseases, Diabetes and Cancer
377 Dietary fat intake and risk of stroke in male US healthcare professionals: 14 year prospective cohort study
The ‘particularly reduced fat varieties’ was not the conclusion of either paper. The 376 paper did not want to make conclusive recommendations on the differences in health between whole milk and reduced fat milk for the following reason:
“Nevertheless, persons who choose to drink fat-reduced milks will almost certainly have adopted other “healthy’ behaviours, and these will undoubtedly be responsible for further confounding. These other factors cannot all be known, but they will be responsible for biases, which cannot possibly be estimated or allowed for. No reasonable conclusions can therefore be based on these data and we refrain from conducting any kind of meta-analysis or summary statistics.”
Generally observational studies find people who drink reduced fat milk have lower odds ratios potentially confounded by other healthy behaviours. They did mention one study that found:
“In another case-control study the odds ratio for MI were significantly reduced (0.36; 0.13, 0.99) in subjects within the top quartile of adipose tissue C15.0 levels.”
The 15:0 fatty acid is found in ruminants and so can be used as a marker of dairy fat (and ruminant fat) consumption. The more dairy fat consumed the more 15:0 will likely end up in adipose tissue. Those in the top quartile would have likely consumed more full fat dairy and whole milk. This study at least suggests that dairy fat is inversely associated with myocardial infarctions. The authors conclude with:
“In the absence of evidence from large randomised trials the statement of German and Dillard is therefore most apposite: “Such hypotheses (about fat-reduced milks) are the basis of sound scientific debate; however they are not the basis of sound public health policy’.”
The authors of the 377 paper conclude by saying:
“We observed no statistically significant associations in this large cohort between intake of total fat, specific types of fat, or cholesterol and risk of ischaemic, haemorrhagic, or total stroke. In addition, consumption of red meats, high fat dairy products, nuts, or eggs did not seem to be related to risk of stroke.”
It appears the dietary guidelines have misrepresented the studies they cite. One study concluded by saying that without RCTs, recommending reduced fat milk is not the basis of sound public health policy, the other found total fat, types of fat and high fat dairy to not be related to the risk of stroke.
“The proportion of total fat and saturated fat content in some milk, cheese and yoghurts has led to the recommendation that reduced fat varieties should be chosen on most occasions.”
The guidelines in section 3.1 to recommend reducing saturated and total fat consumption, but the cited studies don’t support either recommendation. Instead they find low carbohydrate, high fat diets are equal to or better than low fat, high carbohydrate diets for weight loss and that dietary fat improves blood lipids relative to carbohydrate . Saturated fatty acids are also not associated with cardiovascular disease and are inversely associated with atherosclerosis .
“Two proposed mechanisms link the consumption of milk, yoghurt and cheese products with a reduction in cardiovascular risk. Firstly, the consumption of milk, yoghurt and cheese products has been linked to an increase in the levels of high density lipoprotein (HDL) cholesterol.”
This proposed mechanism is out of touch with the recommendations. HDL-C is increased by dietary fat, especially saturated fat, relative to carbohydrate . Therefore the increase in HDL-C, the proposed mechanism by which dairy reduces the risk of cardiovascular disease, is proportional to the total dairy fat consumed.
Full fat dairy may be preferable to reduced fat dairy as dairy fat is rich in fat soluble vitamins such as A, D and K2, and also contains health promoting fats such as butyric acid (4:0) and other short to medium chain fats, long chain omega 3 PUFA and healthy trans-fats such as vaccenic acid and conjugated linoleic acids.
Butyric acid comprises 3-4% of dairy fat and short and medium chain fats comprise roughly 11-12% of dairy fat . Butyric acid is likely to be the main reason why soluble fibre is healthy. (Those values may be roughly 50% higher if grass-fed, which is based on assumptions that dairy in the USDA database are from grain-fed cows, the milk from the sheep and goats are grass-fed and the physiology between the species is not significantly different). Soluble fibre is fermented by bacteria in the colon and butyric acid is a by-product, the butyric acid then nourishes the colon as its primary fuel source. Butyric acid decreases inflammation intestinal permeability and is preventative against weight gain and insulin resistance . Short and medium chain fats (4-12 carbon length) are more likely to be converted into ketones. Ketogenic diets increase mitochondrial biogenesis , which may be therapeutic for a number of metabolic, age-related, neurodegenerative and psychiatric diseases . Medium chain fats may also aid in weight loss by increasing fat metabolism and thermogenesis . (This evidence also supports the consumption of coconut-based foods, which is the richest source of medium chain triglycerides). Long chain omega 3 PUFA don’t need a mention and I’ve discussed the healthy trans-fats previous.
Vitamin K2 is an underappreciated and relatively unheard of essential fat-soluble vitamin. Fatty meats, organ meats, eggs and cheese are the best sources and are in the form of menaquinone-4, vitamin K2 can also be found in some fermented foods as menaquinone-7 . Vitamin K2 is responsible for activating vitamin A and vitamin D dependent proteins , moving calcium from soft tissue such as artery walls to use it in mineralising bones , which makes it effective at preventing both cardiovascular disease and osteoporosis , as well as other functions in several organs such as the brain, pancreas and salivary glands . The health benefits from vitamin K2 are not seen with vitamin K1 (phylloquinone) consumption . Humans do not convert vitamin K1 into K2 and the K2 from intestinal bacteria is barely absorbed.
As a fat-soluble vitamin its intake depends on the quantity of fat consumed. Americans, like Australians, have been told to reduce animal fat and cholesterol for decades. With the saturated fat/cholesterol phobia we have cut the fat off our meat, stopped eating organ meats, choose reduced fat dairy and throw out the yolks, which leaves cheese. Cheese is negatively associated with CHD and is a major source of K2 our diet . This is probably because it’s now our major source of animal fat. Even reduced fat cheddar cheese would have a fair amount of K2 are it is roughly 16-24% fat by weight. Vitamin K2 is one factor that can explain why dairy is inversely associated with cardiovascular disease. What’s also interesting is that vitamin K2 must have a very beneficial effect on health to overcome confounding variables related to its consumption and unhealthy lifestyles.
“In contrast to phylloquinone, intake of menaquinone (mainly MK-4 from eggs and meat, and MK-8 and MK-9 from cheese) is not related to a healthy lifestyle or diet, which makes it unlikely that the observed reduction in coronary risk is due to confounding.”
The Value of Dairy, Calcium and Vitamin D
Despite being concerned with whole food rather than nutrients, the guidelines focus almost exclusively on calcium in regards to dairy consumption. This is demonstrated by:
“The traditional nutritional rationale for the inclusion of dairy foods such as milk, cheese and yoghurt is their high calcium content and the positive relationship between calcium and bone mass.”
“Alternatives to milk, cheese and yoghurt include calcium-enriched legume/bean milk products such as calcium enriched soy drinks.”
However, these alternatives to dairy foods are very different nutritionally. Calcium enriched legume milk products may compare well on calcium, but they likely do not contain vitamins A, B12, D and K2, long chain omega 3’s and conjugated linoleic acids . As discussed above vitamin K2 is an essential nutrient and very useful in preventing arterial calcification and osteoporosis. Without vitamin K2, calcium enriched foods may similarly increase the risk of myocardial infarction as calcium supplements do.
If calcium enriched foods aren’t an alternative to dairy, then what is? There are people who have lactose intolerance or allergic reactions to dairy proteins. Dairy is included in the diet mostly for calcium, but there are more factors involved in calcium balance and bone mineral density than just dietary calcium.
Vitamin D greatly increases calcium absorption. Calcium absorption is 65% higher when vitamin D blood levels are at 86.5 nmol/l, relative to 50 nmol/l. Both vitamin D blood levels are in the reference range, but the authors consider this to be a sub-optimal range for calcium absorption, instead they suggest the reference range for 25-hydroxyvitamin D should be 80-90 nmol/l . If a young or middle aged adult increased their calcium absorption by 65% the RDI could effectively by lowered from 1,000 mg to 606 mg for them. Even without an emphasis on vitamin D our calcium requirement for men and women may be 741 mg . This now means increasing vitamin D could reduce the requirement down to 449 mg (~450 mg). Now consider that 2.8% of New Zealanders aged 15 and over have a vitamin D deficiency (17.5 nmol/l) and 27.6% had a vitamin D insufficiency (37.5 nmol/l), or that the Geelong Osteoporosis study found the average vitamin D levels in summer were 70 nmol/l and in winter were 56 nmol/l . Even 70 is below the current 75 nmol/l cut-off for vitamin D sufficiency. Not many Australians have ideal vitamin D blood levels if ideal is 80-90 nmol/l (perhaps 80 in winter and 90 nmol/l in summer). What is evident is that Australians and New Zealanders have a large room for improvement in increasing calcium absorption.
We may have low vitamin D blood levels because the adequate intake (AI) is too low. The AI is 5 µg for people 50 years and younger, 10 µg for people aged 51-70 and 15 µg for people aged 70+. The upper level is 25 µg for infants and 80 µg for everyone else . The AI may be good enough to prevent rickets but isn’t high enough to achieve optimal calcium absorption. One study found most people were able to reach 100 nmol/l with about 100 µg of vitamin D and 240 µg was needed for 97.5% of the population to have a vitamin D blood level of 100 nmol/l, while not toxicity occurred from vitamin D intakes of 250 µg . The intake of vitamin D needed for 100 nmol/l of 25-hydroxyvitamin D varies greatly between individuals and depends on factors such as body weight . Vitamin D toxicity occurs when 25-hydroxyvitamin is over 200 nmol/l, which requires an intake of 1,000 µg per day . Maximum vitamin D intake from sunlight is only 500 µg per day , therefore it’s unlikely that vitamin D toxicity could occur naturally, unless one is either vitamin A or K2 deficient .
Current sun exposure guidelines may be too conservative and largely contribute to the widespread low levels of 25-hydroxyvitamin D in Australians. Vitamin D has potent anti-cancer effects. UVA is responsible for skin cancers and depletes vitamin D, while UVB is used to synthesise vitamin D. UVA is around all day and can penetrate glass, clothing and sunscreen; UVB is only around while the UV index is greater than 3 and does not have the same penetrance . Taking all of this into account it seems that the UVA:UVB ratio is predictive of skin cancer and is best kept low. Sufficient midday sun exposure to as much of the body as possible to meet the vitamin D targets outlined above, while minimising sunscreen, and sunlight exposure through windows and clothing will keep the UVA:UVB ratio low, ensure good vitamin D levels and reduce the risk of osteoporosis and skin cancer and other forms of cancer.
The authors of the 376 study dismiss the idea that because our hunter-gatherer ancestors had strong bones without consuming dairy, therefore we don’t need to consume dairy either. They dismiss it on the basis that our diet has changed. Indeed it has changed. Most Australians consume a highly refined diet largely devoid of key nutrients for bone health (such as vitamin K2), have poor vitamin D levels from limited sun exposure and we now also consume a grain-based diet, which reduces calcium absorption from phytic acid and compromises vitamin D metabolism . A return to a diet and sun exposure based on our hunter-gatherer ancestors could produce strong bones without needing dairy.
An alternative to dairy would therefore include optimal vitamin D from mostly sunlight (to enhance calcium absorption) and other foods that have similar nutrients as dairy foods do, while assuming one consumes the recommended amount of fruit and vegetables.
“Milk, cheese and yoghurt are a good source of many nutrients, including calcium, protein, iodine, vitamin A, vitamin D, riboflavin, vitamin B12 and zinc.”
Foods that are food sources in these nutrients (except calcium) are other animal-based foods, such as meat, fish (including shellfish), eggs and organs. All have highly bioavailable protein, with a complete amino acid profile and include nutrients derived from amino acids such as carnitine, carnosine, creatine, glutathione and taurine. Fish, eggs and organs are good sources of iodine, eggs and liver are good sources of vitamin A. All are good sources of riboflavin, vitamin B12 and zinc as well as vitamin B5, K2, selenium and long chain omega 3’s (which dairy is also a good source of). Meat from ruminant animals is also a good source of the healthy trans-fats, vaccenic acid and conjugated linoleic acids. Many of the nutrients listed above are found abundantly in other animal foods and animal foods are often the only good or unique source of them .
This suggests that an alternative to dairy is not calcium-enriched legume milks, but rather animal foods and ideal levels of vitamin D. Although if dairy is replaced with animal foods and vitamin D in the context of a highly refined diet low calcium could become a problem, but in a highly refined diet health problems are ubiquitous anyway.
Conclusion
Raising HDL-C and vitamin K2 are some mechanisms that may explain how dairy foods decrease the risk of cardiovascular disease. These mechanisms are proportional to the amount of dairy fat consumed. Dairy fat contains nutrients such as vitamins A, D, K2 and healthy fats such as butyric acid, other short/medium chain fats, long chain omega 3’s, vaccenic acid and conjugated linoleic acids. Therefore full fat dairy should be chosen to maximise health benefits when consuming dairy.
80-90 nmol/l, or even 100 nmol/l, are ideal blood levels of 25-hydroxyvitamin D for calcium absorption, as well as other health benefits. 240 µg is needed for 97.5% of the population to achieve a blood level of 100 nmol/l, although most people only need 100 µg and this depends on factors such as body weight. The AI for vitamin D should be changed to 100 µg and an RDI should be made at 240 µg. The recommendations regarding sun exposure should be changed to increase noon sun exposure to as much of the body as possible to promote health and not be responsible for skin cancers.
Alternatives to dairy should only include other animal foods along with an ideal blood level of 25-hydroxyvitamin D (80-90 or 100 nmol/l). Animal-based foods are rich sources of the nutrients dairy foods are also rich in. Many of the nutrients are only found adequately in animal-based foods and some nutrients are exclusive to animal foods. This makes animal-based foods a better alternative to dairy than plant-based dairy substitutes. | http://www.stevenhamley.com.au/2012/02/dga-2011-dairy-and-alternatives.html |
United States Court of Appeals
FOR THE EIGHTH CIRCUIT
___________
No. 05-2647
___________
United States of America, *
*
Appellee, *
* Appeal from the United States
v. * District Court for the
* Eastern District of Missouri.
Anthony C. Littrell, *
*
Appellant. *
___________
Submitted: January 11, 2006
Filed: March 9, 2006
___________
Before BYE and COLLOTON, Circuit Judges, and BOGUE,1 District Judge.
___________
BOGUE, District Judge.
Anthony C. Littrell (“Littrell”) was convicted on one count of conspiracy to
possess, manufacture, or distribute more than 500 grams of methamphetamine, in
violation of 21 U.S.C. §§ 841(a)(1) and 846; one count of conspiracy to possess
pseudoephedrine knowing it would be used to manufacture methamphetamine, in
violation of 21 U.S.C. §§ 841(c)(2) and 846; three counts of manufacturing and
possessing methamphetamine with intent to distribute, in violation of 21 U.S.C.
§ 841(a)(1); possessing pseudoephedrine knowing it would be used to manufacture
1
The Honorable Andrew W. Bogue, United States District Judge for the District
of South Dakota, sitting by designation.
methamphetamine, in violation of 21 U.S.C. § 841(c)(2); and two counts of possessing
a firearm in furtherance of drug-related activity, in violation of 18 U.S.C. § 924(c)(1).
The district court2 sentenced Littrell to 480 months’ imprisonment and 5 years’
supervised release. Littrell appeals, arguing the district court erred (1) in denying his
motion for judgment of acquittal, (2) in denying his motion to suppress evidence, and
(3) in denying his motions in limine. Littrell also argues his conviction must be
reversed due to (1) improper vouching for government witnesses by the prosecutor,
and (2) misrepresentation of evidence during closing arguments by the prosecutor.
For the reasons that follow, we affirm.
FACTUAL AND PROCEDURAL BACKGROUND
On January 16, 2002, Investigator Bobby Kile (“Investigator Kile”) with the
Lake Area Narcotics Enforcement Group, Lake of the Ozark, Missouri, applied for a
search warrant to search a residence at 1702 Hecker Road, Owensville, Missouri. The
affidavit in support of the application stated a confidential informant (“CI”) had been
inside the residence, which Littrell occupied. The CI had observed quantities of
methamphetamine and drug paraphernalia inside the residence within forty-eight
hours of the application. The CI also reported that, while inside the residence, the CI
had heard a conversation between Littrell and an unknown individual relating to the
production of methamphetamine. The affidavit stated the CI had provided accurate
and reliable information which Investigator Kile found to be true while effecting
felony arrests. The affidavit also stated a traffic stop had been conducted on a vehicle
that belonged to a known associate of Littrell’s and which had been seen at Littrell’s
residence. A search of the vehicle had uncovered methamphetamine, and one of the
occupants of the vehicle was arrested. The affidavit in support of the search warrant
did not mention that Littrell and his wife were present in the vehicle but were not
charged for any crime in relation to the stop. The search warrant was executed on
2
The Honorable Catherine D. Perry, United States District Judge for the Eastern
District of Missouri.
-2-
January 22, 2002. The search uncovered methamphetamine, Lithium batteries,
glassware and filters that contained powder, pressure tanks that tested positive for
anhydrous ammonia, Coleman fuel, chemicals, and battery casings.
On November 30, 2002, Investigator Matthew Oller (“Investigator Oller”) with
the East Central Drug Task Force, Mexico, Missouri, applied for another search
warrant for Littrell’s residence. The affidavit in support of the application recited that
Investigator Oller interviewed individuals who were caught stealing anhydrous
ammonia, and one of the individuals stated he was stealing the anhydrous ammonia
for Littrell. The individual stated he had been present in the past when Littrell cooked
methamphetamine, at which time the individual had received a large anhydrous
ammonia burn on his left arm, which the individual showed the officer. Finally, the
individual stated Littrell kept a pressure tank containing anhydrous ammonia behind
the residence, and that Littrell used the anhydrous ammonia to make
methamphetamine. The affidavit also indicated Investigator Oller participated in the
January 22 search of the residence, and recited the items uncovered during that search.
Finally, the affidavit stated that a reliable CI had told the officer the CI had purchased
methamphetamine from Littrell in the previous six months and had discussions with
Littrell about his involvement in the production of methamphetamine. The search
warrant was issued and executed on November 30, 2002. The search led to seizure
of items related to the production of methamphetamine and a large amount of cash.
On January 25, 2003, Investigator Kile applied for a third search warrant for the
Littrell residence. The affidavit in support thereof recited the information uncovered
during the first two searches. The affidavit then stated that police had received a
report from an anonymous tipster of a strong and unusual odor coming from Littrell’s
residence. Investigator Kile drove past the residence and detected an odor consistent
with the manufacture of methamphetamine, with the strongest odor coming from the
front of the residence. The search warrant was issued the same day. The search was
-3-
conducted on February 3, 2003. The search again uncovered methamphetamine and
numerous items related to its manufacture and distribution.
After indictment, Littrell moved to suppress the evidence seized during the
searches. The district court concluded that probable cause supported the issuance of
all three warrants and denied the motion. Specifically, the district court ruled the
reliability of the CI in the first warrant application was established. The court
observed that the warrant application should have stated that Littrell and his wife were
not arrested during the traffic stop. The court ruled, however, that this omission did
not make the application false or misleading, and would have provided additional
support for the probable cause determination. The court also ruled that the second and
third warrants were not invalid simply because they relied on the first warrant. As to
the second warrant only, the court concluded the apparently inconsistent times on the
application and the warrant did not show the judge had failed to give the application
adequate consideration. As to the third warrant, the court held the officer’s
corroboration of the anonymous informant’s tip, along with the evidence located
during the first two searches, provided sufficient probable cause to believe
methamphetamine and related items would be found in Littrell’s home. Finally, the
court ruled the officers who executed the first two warrants did not exceed the scope
of the warrants, both of which authorized searches for “methamphetamine” only.
Although many items in addition to methamphetamine were seized, the court
observed, all the items were seized from places where methamphetamine could have
been secreted, and the illegal purpose of the items was immediately apparent.
Also before trial, Littrell moved in limine to exclude items seized during
execution of two later warrants, and to exclude evidence related to a stop and search
of his vehicle in North Carolina. The district court denied the motion as to evidence
seized during a March 31, 2003, search of the residence, granted the motion as to
evidence seized during a June 16, 2003, search, and denied the motion as to evidence
seized during a search of Littrell’s trailer in North Carolina on April 24, 2003.
-4-
During his closing argument at Littrell’s trial, while summarizing for the jury
the amounts of methamphetamine for which Littrell could be held responsible, the
prosecutor miscalculated the amount of methamphetamine shown by the evidence.
The prosecutor also made several statements regarding witnesses. The prosecutor
stated that Investigator Kile was “a meticulous investigator,” that “[h]e was just telling
the truth as he knew it,” and that “there [wa]s a reason to believe that his testimony
was reasonable.” The prosecutor also made other comments regarding other witnesses
and their truthfulness, stating, “you knew [the] Investigator was telling the truth,” and
“[i]t was clear he was telling the truth.” As to a witness who identified a gun, counsel
stated, “And we knew it [was the gun], and we could take his testimony to the bank.”
The prosecutor also made statements about the truthfulness of Littrell’s testimony on
certain incidents. Littrell did not object to any of these comments by the prosecutor.
After Littrell was convicted, he renewed his motion for a judgment of acquittal
or for a new trial, arguing that the evidence was insufficient to sustain a conviction on
Count I, and that the district court had erred in its earlier rulings on the motion to
suppress and the motions in limine. The district court denied the motion, concluding
coconspirator testimony, along with evidence of amounts seized from Littrell, easily
established the amount of methamphetamine necessary to support the 500-gram
threshold. The court noted the overwhelming evidence and concluded there was no
basis for a judgment of acquittal or new trial. Lastly, the court also concluded its
earlier rulings were correct, and Littrell’s constitutional rights were not violated.
DISCUSSION
A. Motion for Judgment of Acquittal/New Trial
First, as to the denial of the motion for acquittal on the conspiracy count, “we
must employ a very strict standard of review on this issue.” United States v. Cook,
356 F.3d 913, 917 (8th Cir. 2004). We view “the evidence in the light most favorable
to the government, resolving evidentiary conflicts in favor of the government, and
accepting all reasonable inferences drawn from the evidence that support the jury’s
-5-
verdict.” Id. (citation omitted). To prove the conspiracy count, the government had
to show 1) an illegal conspiracy existed, 2) Littrell knew about the conspiracy, and 3)
Littrell knowingly became a part of the conspiracy. United States v. Monnier, 412
F.3d 859, 861 (8th Cir. 2005). In this case, the government also had to prove the
conspiracy involved over 500 grams of methamphetamine.
Littrell argues the government failed to prove that the conspiracy involved over
500 grams of methamphetamine, claiming the evidence presented only supports
244.15 grams. However, taken in the light most favorable to the government, the
evidence met the 500-gram threshold. Evidence was presented regarding a large
amount of methamphetamine seized from Littrell’s residence; a tennis-ball sized
quantity that co-defendant Michael Phillips saw Littrell manufacture; baggies of the
drug a co-defendant stated came from Littrell; large amounts of pseudoephedrine
seized from Littrell’s property; amounts of pseudoephedrine delivered by Phillips; and
still more pseudoephedrine that Phillips possessed upon his arrest. Additional
evidence was presented regarding large amounts of cash and pseudoephedrine.
Because a defendant in a conspiracy may be “held responsible for all reasonably
foreseeable drug quantities that were in the scope of the criminal activity that he
jointly undertook,” United States v. Jimenez-Villasenor, 270 F.3d 554, 561 (8th Cir.
2001), we conclude the district court did not err in denying the motion for judgment
of acquittal or new trial.
B. Motion to Suppress
Littrell next argues the district court erred in denying his motion to suppress,
claiming probable cause did not exist to support the first warrant, and that the second
and third warrants were obtained based on evidence illegally seized during the first
search. “When considering a suppression order, we review the district court’s factual
findings for clear error and review de novo its conclusion about whether the Fourth
Amendment was violated during the search.” United States v. Janis, 387 F.3d 682,
686 (8th Cir. 2004). We will affirm the district court’s decision on a suppression
-6-
motion “unless it is not supported by substantial evidence on the record; it reflects an
erroneous view of the applicable law; or upon review of the entire record, [we are] left
with the definite and firm conviction that a mistake has been made.” United States v.
Perez-Perez, 337 F.3d 990, 993-94 (8th Cir. 2003) (citation omitted).
Littrell claims the reliability of the CI, whose information provided part of the
basis for issuance of the first warrant, was not established sufficiently. “Information
from a confidential informant may be sufficient to establish probable cause if it ‘is
corroborated by independent evidence’ or if the informant ‘has a track record of
supplying reliable information.’” United States v. Vinson, 414 F.3d 924, 930 (8th Cir.
2005) (quoting United States v. Gabrio, 295 F.3d 880, 883 (8th Cir. 2002)). Although
Littrell cites several cases wherein greater evidence of a CI’s reliability was presented
to the issuing magistrate, such does not demonstrate the lack of reliability of the CI
in this case. The CI’s reliability was established in the affidavit supporting the first
warrant application, wherein Investigator Kile stated he had worked with the CI for
three years and the CI had provided accurate and reliable information Investigator
Kile found to be true in effecting felony arrests. The first warrant application also
contained information sufficient to show probable cause for the search. Thus, the first
search warrant was valid. The second and third warrant applications contained
sufficient indicia of probable cause, partially based on the evidence obtained during
the first search. Thus, each of the warrant applications was supported by probable
cause. Accordingly, the district court did not err in denying the motion to suppress.
C. Improprieties in Government’s Closing Argument
Finally, Littrell argues the prosecutor made improper remarks vouching for the
credibility of witnesses and improperly calculated drug quantities during closing
argument. “The district court enjoys broad discretion in controlling closing
arguments. We will overturn a conviction only for a clear abuse of that discretion.”
United States v. Beaman, 361 F.3d 1061, 1064 (8th Cir. 2004). Littrell did not object
or otherwise bring these issues before the trial court, however, so we review for plain
-7-
error. United States v. Chauncey, 420 F.3d 864, 876 (8th Cir. 2005). “We will
reverse under plain error review only if the error prejudices the party’s substantial
rights and would result in a miscarriage of justice if left uncorrected. Plain error
review is extremely narrow and is limited to those errors which are so obvious or
otherwise flawed as to seriously undermine the fairness, integrity, or public reputation
of judicial proceedings.” United States v. Yellow Hawk, 276 F.3d 953, 955 (8th Cir.
2002) (citations omitted). Put another way, “[i]f an arguably improper statement made
during closing argument is not objected to by defense counsel, we will only reverse
under exceptional circumstances.” United States v. Eldridge, 984 F.2d 943, 947 (8th
Cir. 1993) (citation omitted).
The prosecutor made several statements during his closing that, at first glance,
arguably appear to be a form of vouching for witness credibility. Comments were
made about Investigator Kile being “a meticulous investigator,” “telling the truth as
he knew it,” and there being “a reason to believe that his testimony was reasonable,”
as well as other statements. Other comments were made about how it was clear and
how the jury could know another investigator was telling the truth. Finally, the
prosecutor stated the jury “could take [one witness’s] testimony to the bank.” Closer
review, however, shows the statements were not so prejudicial as to warrant reversal.
“Attempts to bolster a witness by vouching for his credibility are normally improper.”
United States v. Jackson, 915 F.2d 359, 361 (8th Cir. 1990) (citation omitted).
Facially, these statements may appear improper but, when taken in the proper context,
the prosecutor’s statements were neither improper nor unduly prejudicial. See United
States v. Vallie, 284 F.3d 917, 922 (8th Cir. 2002). A careful review of the transcript
of the closing arguments convinces us the comments were made as part of the
prosecutor’s review of the evidence before the jury. See Jackson, 915 F.2d at 361.
The prosecutor’s comments about Investigator Kile being meticulous were made
during his recitation of the evidence showing the investigator’s methods in conducting
an investigation. The comment about Investigator Kile “telling the truth as he knew
it” was made in the context of the prosecutor explaining how Investigator Kile treated
-8-
defense counsel during defense counsel’s long cross examination. The comment that
there was a reason to believe Investigator Kile’s testimony was reasonable was made
at the end of a statement showing how he could have lied about the defendant to
bolster the government’s case, but did not do so. Similarly, comments about how the
jury could know the other investigator was telling the truth came while the prosecutor
was explaining how the evidence supported that investigator’s testimony. The last
comment, that the jury could take to the bank the testimony by the government
witness regarding the gun, was made after the prosecutor explained the certainty with
which that witness identified the gun.
“While a prosecutor may not vouch for the credibility of witnesses based on
facts personally known to the prosecutor but not introduced at trial, ‘that does not
mean the prosecutor cannot argue that the fair inference from the facts presented is
that a witness had no reason to lie.’” United States v. Eley, 723 F.2d 1522, 1526 (11th
Cir. 1984) (quoting United States v. Bright, 630 F.2d 804, 824 (5th Cir. 1980)). This
court has cited the Eleventh Circuit’s opinion in Eley on several occasions. See, e.g.,
United States v. Grey Bear, 883 F.2d 1382, 1392 (8th Cir. 1989); United States v.
DeVore, 839 F.2d 1330, 1333 (8th Cir. 1988). We conclude the prosecutor’s
comments were not improper. The prosecutor did not put his personal reputation
behind the testimony of its witnesses. “[P]rosecutors, as well as defense lawyers, may
and must argue as to the credibility of witnesses, and in a case of this kind the issue
of credibility is critical. The very nature of closing argument requires a detailed
analysis of the testimony of each witness and the inferences to be drawn from the
evidence.” Grey Bear, 883 F.2d at 1392. We conclude the prosecutor “merely
suggested reasons why the jury might find the government’s witnesses to be more
credible.” See United States v. Papajohn, 212 F.3d 1112, 1120 (8th Cir. 2000),
abrogated on other grounds by Crawford v. Washington, 541 U.S. 36 (2004).
Further, Littrell did not object to any of the statements by the prosecutor that he now
challenges. Nor did Littrell request a curative instruction or move for a mistrial. Even
-9-
if we were to assume the prosecutor’s statements constituted impermissible vouching,
we would not exercise our discretion and grant Littrell plain error relief.
As to the prosecutor’s comments that Littrell was not telling the truth, these
comments again were not improper. United States v. French, 88 F.3d 686, 688-89
(8th Cir. 1996). However, even assuming the comments were in some way improper,
Littrell would not be entitled to the relief he seeks. To establish an entitlement to
relief under the plain error doctrine, Littrell must show prejudice–that is, a reasonable
probability that the outcome would have been different absent the alleged error.
United States v. Dominguez-Benitez, 542 U.S. 74, 81-82 (2004). “If prosecutorial
misconduct allegedly has occurred, a reviewing court looks into its prejudicial impact
by assessing the cumulative effect of the misconduct, determining if the court took
any curative actions, and gauging the strength of the evidence against the defendant
in the context of the entire trial.” Id. In this case, any statements regarding Littrell’s
truthfulness were not unfairly prejudicial, for the government presented overwhelming
evidence of Littrell’s guilt. The district court also instructed the jury that closing
arguments are just that, argument, and are not evidence of anything. As noted in
French, this court “has denied a reversal of a conviction when a prosecutor has used
stronger and more personal language.” Id.; see United States v. Peyro, 786 F.2d 826,
831-32 (8th Cir. 1986) (affirming conviction in which prosecutor made statements
such as, “The man is an obvious liar.”). The Peyro court affirmed the conviction
although defense counsel had objected to the prosecutor’s statements. In this case, no
objections were made. We do not find the comments about Littrell’s truthfulness to
be improper. Further, we find no plain error so prejudicial as to warrant reversal in
this case.
Finally, the erroneous calculation of drug quantity (which the government
admits occurred) did not unfairly prejudice the defendant. “We have indicated that
an improper argument is less likely to have affected the verdict in a case when the
evidence is overwhelming than in a case where the evidence is weak.” United States
-10-
v. Cannon, 88 F.3d 1495, 1503 (8th Cir. 1996). As noted above with regard to
Littrell’s motion for judgment of acquittal, ample evidence supported the finding of
drug quantity exceeding 500 grams. Furthermore, the district court instructed the jury
that arguments were not evidence, and that it should make its findings based on the
evidence presented. The district court also instructed the jury that certain charts and
summaries, presented to help explain evidence, were not evidence or proof of any
facts. The court instructed that if these charts and summaries did not correctly reflect
the facts shown by the evidence, the jury was to disregard the charts and summaries
and determine the facts from the evidence presented. Moreover, even if the jury were
misled by the closing argument, there is no showing of prejudice to Littrell. It is
undisputed that the government proved a minimum of 244 grams of methamphetamine
relating to the conspiracy, which would produce an advisory guidelines range of 168
to 210 months’ imprisonment, and the court imposed a sentence of only 120 months’
imprisonment on that count. In sum, the prosecutor’s closing argument did not
“undermine the fairness, integrity, or public reputation of judicial proceedings.”
Yellow Hawk, 276 F.3d at 955. Given the district court’s broad discretion in
controlling closing arguments, and Littrell’s failure to object, we conclude that
exceptional circumstances warranting reversal are not present in this case.
D. Motions in Limine
Finally, Littrell contends the district court erred in denying his motions in
limine. Reviewing the district court’s decision denying the motions in limine for an
abuse of discretion, United States v. Gianakos, 415 F.3d 912, 919 (8th Cir. 2005), we
conclude that no error occurred. See 8th Cir. R. 47B.
CONCLUSION
For the foregoing reasons, we affirm in all respects.
______________________________
-11-
| |
Nearly 70 cars have crashed on a major US highway. (AP)Police did not say how many people were hurt but said injuries ranged from minor to life-threatening. (AP)The cars crashed in a chain reaction on I-64 in eastern Virginia on Sunday morning (local time) because of fog and ice, authorities said. (CNN)
In some spots, vehicles were so squeezed together that firefighters and emergency responders had to step from car to car to pull people out.
A witness, Bray Hollowell, also posted a short video showing a number of cars in the crash.
Virginia State Police said heavy fog and ice were present at Queens Creek Bridge at 7.51am when the crashes began.
Photos from the York-Poquoson Sheriff's Office and the Virginia State Police show the extent of the backup and damage. (CNN)
Virginia State Police Sgt Michelle Anaya said authorities do not know what caused the initial crash, but the fog and ice were factors. | |
A powerful biography in poems about a trailblazing artist and a pillar of the Harlem Renaissance—with an afterword by the curator of the Schomburg Center for Research in Black Culture.
Augusta Savage was arguably the most influential American artist of the 1930s. A gifted sculptor, Savage was commissioned to create a portrait bust of W.E.B. Du Bois for the New York Public Library. She flourished during the Harlem Renaissance, and became a teacher to an entire generation of African American artists, including Jacob Lawrence, and would go on to be nationally recognized as one of the featured artists at the 1939 World’s Fair. She was the first-ever recorded Black gallerist. After being denied an artists’ fellowship abroad on the basis of race, Augusta Savage worked to advance equal rights in the arts. And yet popular history has forgotten her name. Deftly written and brimming with photographs of Savage’s stunning sculpture, this is an important portrait of an exceptional artist. For fans of One Last Word: Wisdom from the Harlem Renaissance. | |
“That peace which is the portion of the chosen servants of God is seldom unmixed with interior struggles.”
St. Elizabeth Ann Seton
“Prudence consists in speaking about important matters only and not relating a lot of trifles that are not worth saying.
St. Louis de Marillac
Meet Our New Associates: Nellie Derrenkamp
By AJ Keith, Communications intern
Nellie Derrenkamp (center) made her commitment as an Associate in Mission alongside companion S. Terry Thorman (left) and Director of Associates Chanin Wilson in June 2018.
In June 2018, Nellie Derrenkamp decided to devote herself to the spirit of the Sisters of Charity Community by becoming an Associate in Mission. Her natural selfless demeanor answers many of the key pieces of the Sisters of Charity mission, and despite an inundated schedule of work and family, Nellie felt compelled to make her commitment as an Associate this past year.
For nine years, Nellie worked in Mother Margaret Hall nursing facility which is how she was first introduced to the Sisters of Charity. Moved by her patients, she grew fond of the Sisters and their dedication to serving the needs of the community. Nellie recognized that the Sisters were ideal and active citizens, which she attempts to reflect in her own service. “Their dedication to the community and helping poorer communities is really what inspired me the most,” she says.
Ultimately this inspiration convinced her to make her commitment as an Associate. Since then, she has been looking for a branch of service that she is truly passionate about. In the meantime, she continues her nursing career at Cincinnati Children’s Hospital which she believes responds to her commitment to the Sisters because she shares her talents with those in need. Nellie also recognizes the needs of her family in her native country of the Philippines which urge her to provide support for them.
Juggling work, a teenager and support for her family overseas can be overwhelming, she admits, but her enduring faith has provided a stable foundation for her life. “I just have to pray that God will give me good health and will help me serve others,” she says. Nellie attends Mass whenever possible to nourish her spiritual journey and to help her better live out the Gospel values.
Nellie’s gentle temperament is exercised each day to her patients and she hopes to contribute her talents to new forms of service in the upcoming year. She hopes that her service will be different from her work in healthcare to allow her to widen her eyes to the issues of the community. Whatever comes her way, Nellie insists that she would not have been able to persevere without her faith. With her steady faith in God and a career that allows her to act justly to all that she comes across, Nellie is living the Gospel values in a unique and caring way. She believes that all people are capable of caring for others and active service, as she says, “You just have to try because that’s all you can do.”
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One reason Lava Beds National Monument is such a special place to contemplate cultural history is that it contains two types of rock art, or rock imagery— carved petroglyphs and painted pictographs. All of the Monument’s rock imagery is located in the traditional territory of the Modoc people and their ancestors or predecessors.
It is hard to determine the age of rock art. This is especially true of petroglyphs, since material was removed in their creation, not added. It is possible that some of these images at Lava Beds National Monument were made more that 6,000 years ago. Estimating the age of an individual petroglyph based on weathering is complicated by the number of times it may have been inundated in water as Tule Lake rose and fell around the island that later became known as Petroglyph Point. Interestingly, some of the geometric patterns found in the rock imagery here appear on household items up to 5,000 years old from nearby Nightfire Island. Could some of the same people have carved those same patterns into the rocks at Petroglyph Point? With over 5,000 individual carvings, this site is one of the most extensive representations of American Indian rock art in California—it is possible that dozens or even hundreds of generations of artists paddled out in canoes, sharp sticks or stones in hand, to leave their mark here in the soft volcanic tuff. As you walk along the base of the cliff, a trail brochure will guide you past petroglyphs and through stories of Petroglyph Point and the native peoples who have gone before and continue today.
Most of the pictographs at Lava Beds National Monument are found around cave entrances. They are painted in black, produced from a charcoal base mixed with animal fat, and white, made with a clay base. Occasionally red was used, likely made from substances obtained through trade with Paiute Indians to the east. Since scientific dating techniques are possible with the carbon-based materials in some pigments, some pictographs at Lava Beds National Monument have been dated to 1,500 years ago. However, since Lava Beds remains a sacred landscape for people of Modoc-Klamath descent, it is possible that other images are relatively recent.
As with petroglyphs, guessing the age of an individual image by its condition can be deceiving. Images exposed to direct sun, wind, and rain fade much faster than those in more sheltered areas. Excellent examples of pictographs can be seen at Symbol Bridge and Big Painted Cave on boulders along the trail and walls around the entrances. Perhaps you can imagine generations of artists making their way out to caves such as these with paint supplies and an idea in mind. If you look closely, most lines on such pictographs seem to be about the width of a human finger—literally applied by hand.
You can reach the Lava Beds National Monument by taking Hill Road from Stateline Road (Hwy 161). Travel south east on Hill Road past the Klamath Basin National Wildlife Refuge Visitor Center, until you see a sign advising you are entering the Lava Beds National Monument.
Petroglyph Point is located on the eastern edge at Tule Lake.
Summer: 8:00 a.m. to 6:00 p.m.; Fall, Winter, Spring: 8:30 a.m. to 5:00 p.m.
The area has rough terrain, and is not ADA accessible although the Visitors Center in the Monument and several trails are accessible. Please check the park website for more details. | https://www.sierranevadageotourism.org/content/petroglyph-point-lava-beds-national-monument/sie3D0581DA1890E633B |
Known as:
Optimal bitonic tour
In computational geometry, a bitonic tour of a set of point sites in the Euclidean plane is a closed polygonal chain that has each site as one of its…
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Papers overview
Semantic Scholar uses AI to extract papers important to this topic.
2014
2014
Product Development in Dark Tourism : Case: Topography of Terror (Berlin, Germany)
Denise Böhme
2014
Tampereen ammattikorkeakoulu Tampere University of Applied Sciences Degree Programme in Tourism DENISE BÖHME: Product Development…
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2011
2011
CMPUT 675 : Approximation Algorithms Fall 2011 Lecture 18 ( November 8 ) : Euclidean TSP
Seyed Sina Khankhajeh
2011
Euclidean TSP is a subset of Travelling Salesman Problem in which distances are on Euclidean plane, i.e. the instances are on R 2…
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2009
2009
Not being (super)thin or solid is hard: A study of grid Hamiltonicity
Esther M. Arkin
,
Sándor P. Fekete
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Henry Xiao
Comput. Geom.
2009
We give a systematic study of Hamiltonicity of grids - the graphs induced by finite subsets of vertices of the tilings of the…
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Highly Cited
2008
Highly Cited
2008
Traveling Salesperson Problems for the Dubins Vehicle
Ketan Savla
,
Emilio Frazzoli
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Francesco Bullo
IEEE Transactions on Automatic Control
2008
In this paper, we study minimum-time motion planning and routing problems for the Dubins vehicle, i.e., a nonholonomic vehicle…
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2007
2007
Behavioural Impacts of Mobile Tour Guides
Ronny Kramer
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Marko Modsching
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Klaus ten Hagen
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Ulrike Gretzel
ENTER
2007
Electronic tour guides have been developed to personalise guided tours. Also, in contrast to traditional tours, electronic tour…
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2003
2003
Algorithms: A Top-Down Approach
Rodney R. Howell
2003
The current draft and supplemental materials for the text, 'Algorithms: A Top-Down Approach', by Rodney R. Howell
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2002
2002
New Heuristics and Lower Bounds for the Min-Max k -Chinese Postman Problem
Dino Ahr
,
Gerhard Reinelt
ESA
2002
Given an undirected edge-weighted graph and a depot node, postman problems are generally concerned with traversing the edges of…
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1996
1996
L'art à l'épreuve du concept
Danielle Lories
1996
Ce livre propose un examen critique de la maniere dont la question de la definition de l'art a ete abordee par l'esthetique…
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1996
1996
Guaranteeing full fault coverage for UIO-based testing methods
Ricardo de Oliveira Anido
,
Ana R. Cavalli
1996
This paper presents an analysis of the fault coverage provided by the UIO-based methods for testing communications protocols…
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1992
1992
Tour automatique multibroche
Frank Baumbusch
,
Egon Strathmeier
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Bodo Haupt
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Frank Kieselbach
1992
Ce tour automatique multibroche possede au moins deux ensembles broches porte-pieces (18, 20) se deplacant dans les sens X et Z…
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Seniors’ near-vision loss, dementia risk linked?
Significant near-vision loss in older age may correlate with dementia risk, suggests new research that builds on the emerging potential for eye and vision health in detecting neurological disorders.
The doctor of optometry has an important role to play in the prevention and early detection of the ocular and visual changes that herald the onset of Alzheimer's disease.
Presented at the International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders 2017 in Vienna, Austria, the French analysis determined that 1 in 5 study participants—age 65 or older—registering moderate-to-severe near-vision loss at baseline went on to develop dementia within the next dozen years, as compared to only 1 in 10 with no vision loss. Such results drew mixed and skeptical reactions; however, proponents believe the results could help build evidence for a long-sought early warning flag for cognitive decline.
In this prospective, population-based cohort study using The Three-City Study data, 7,722 participants age 65 or older were tracked over the course of 12 years. At baseline, those participants presented as follows: 8.7 percent had mild near-vision loss (20/30 to 20/60), 4.2 percent had moderate-to-severe near-vision loss (20/60 or less) and 5.3 percent had distance-vision loss, per Medscape News.
Of those, 882 participants developed dementia over the course of the study, including 21.2 percent with moderate-to-severe near-vision loss, 17.1 percent with mild near-vision loss and 18.6 percent with distance-vision loss. Only 10.2 percent of participants with no vision loss developed dementia.
Even after adjusting for numerous variables, study authors note that moderate-to-severe near-vision loss still had a greater hazard ratio for dementia than did mild near-vision or distance vision loss.
Maryke Neiberg, O.D., associate dean of academic affairs at Midwestern University Chicago College of Optometry, who has written previously on optometry's role in Alzheimer's disease care, notes that patients typically do have difficulty with near-vision in the beginning stages of the disease, including crowding, alexia and figure-ground difficulties.
"Everyone has had the experience of an older patient with a bag of glasses, all about the same power, but the patient is happy with none of them," Dr. Neiberg writes. "This can often be the first indication of the problem."
Although vision changes naturally occur with age and don't always indicate a more serious condition, patients 60 years and older still should be wary of age-related eye health problems, sometimes occurring without early symptoms. Regular, comprehensive eye examinations are critical in senior years, and evolving understanding of neurological health frequently looks to the eyes as a bellwether.
Eyes into Alzheimer's, dementia?
Alzheimer's disease, a progressive, irreversible neurodegenerative disease, is the most prevalent form of dementia and accounts for an estimated 60-80 percent of dementia among Americans. It's characterized by the buildup of beta amyloid plaques and neurofibrillary (tau) tangles in the brain that affect normal functioning of cells, eventually causing a loss of brain tissue. Until recently, such buildup was only measurable post-mortem, but researchers are now using the eye as a proxy for neural health.
Now, researchers are investigating the use of spectral domain optical coherence tomography (SD-OCT) to determine a correlation between retinal nerve fiber layer thickness and cognition, as well as using hyperspectral imaging to detect retinal changes attributed to increased amyloid deposits. Both methods could provide an invaluable, noninvasive glimpse into the brain that utilizes methods—such as OCT—already employed in many doctors' offices.
"The doctor of optometry has an important role to play in the prevention and early detection of the ocular and visual changes that herald the onset of Alzheimer's disease," Dr. Neiberg wrote in a continuing education article for the California Optometric Association. "We have an even more critical role to play in the education of our patients and the public about the preventable risk factors that are associated with Alzheimer's disease."
Click here to read how doctors' advanced imaging can detect another chronic disease, Parkinson's. | https://www.aoa.org/news/clinical-eye-care/seniors-near-vision-loss-dementia-risk-linked |
Guided Reading in the Upper Grade Classroom: Getting Started
Whether you use a reading workshop approach or not, guided reading is a component of literacy that many K-5 teachers use in their classroom. I want our sessions to have a comfortable feeling where students can ask questions, try new strategies, and work together to become more strategic readers. Setting up this environment takes some work and planning, which is why our class didn't begin meeting until the fourth week of school. I'd like to share some of the fundamentals of getting guided reading off the ground at the beginning of the year.
Planning and Setting Up Guided Reading Sessions
Book Organization
Hopefully your school has a book-room with leveled texts available for checkout. I assumed my school had one when I interviewed and accepted a position. It was only after I accepted that I learned a book-room was not included with the school. The only resources provided were basal leveled trade books. What was I to do?
Knowing that my kids come in more levels than high, medium, and low, I purchased an account with Reading A-Z. If you are not familiar with this wonderful resource, you can print books at various levels and topics for a reasonable price. I printed as many nonfiction topics as possible. With a large stack of single book copies from a printer, I recruited the help of some parent volunteers to help organize it all. I had parents make more copies, fold the books, staple them, place them in a large zip lock bag, and label it with the title and level at the top (Fountas and Pinnell conversion chart). From there all the books were sorted in a tall filing cabinet, A-Z, for easy access.
Selecting Books
Each week I take a moment to look through our book collection. I keep record of who I have met with, what book was read, what skill/strategy was worked on, as well as my observation notes from our meetings together. I use this information to select books for the week and create flexible or strategy groupings based on need. I then place guided reading books in a bin for easy access. For now, we start with books that are at the independent level (95% accuracy) because we are focusing on modeling procedures, thinking, talking, and recording our thoughts on paper. Once routines are mastered, students will read books that are at the instructional level (90%-94% accuracy and 75% comprehension) as well as meet with students of varying levels to talk about specific reading strategies.
Also worth noting is how I determine a student's reading level. I have used a variety of tools, including DRA, Rigby's Running Record kit, informal running records, and STAR testing. Using a combination of these assessments has helped me know where to start. Individual conferences helps me change flexible groupings on a regular basis.
Teaching Procedures for Guided Reading Meetings
My first meetings with guided reading groups involved very little reading. Our topics focused on procedures and expectations. Here are some of the things we discussed/modeled in our first meetings together:
~ First, we discussed how our group will come to the meeting area. For us that means sitting next to each other "EEKK" style in a circle as we don't have a guided reading table to work with. "EEKK" stands for elbow to elbow and knee to knee. A spot is left open for me, as I usually join the group last.
~ Students record the title of the book and date in their notebook. We make sure to uppercase the proper letters, spell it correctly, and underline the title each time. This information goes under the guided reading tab in our reader's notebook.
~ We review guided reading guidelines (provided in the notebook), focusing on participating, listening to each other, and valuing each other's questions and inquiries. I really stress that we are never to laugh at someone's question because one laugh might make that student feel too afraid to ask another question again. Unanswered questions from the session go on a board called, "I Wonder" and we research these answers throughout the week.
~ Note taking. For us, rather than write notes in the reader's notebook, we are starting with post-it notes instead. My reasoning is that post-it notes are easy and friendly to move from page to page. Our format for jotting down notes includes a "*" for interesting information learned, a "?" for anything that is confusing, and a "W" for general questions or wonders. As time progresses we will write more notes directly in the reader's notebook.
General Format for Our Meetings Together
What do you know?- On a typical meeting together students are handed a new book after a workshop lesson has been completed. Students grab their reader's notebook, a pencil, and quietly go to the meeting area where they will follow the procedures above. A quick skim through of the book is completed and students write down anything they already know about the topic in their reader's notebook. They can also record vocabulary that troubles them as well. This usually consumes the first 3 to 4 minutes of our meeting, and I may or may not be present during this time.
Reflect- Once I have joined the group I take a second to reflect on our last meeting together. Often students take the book from our last meeting and finish it independently or re-read it for understanding. We take a moment to discuss the previous read before introducing the new one. With the new book I have students share what they already know about the topic or what they would like to know. Many times I get lucky and have an expert at hand! Vocabulary is not necessarily addressed if it is a nonfiction piece, as this information is modeled as one of the features.
Strategy Focus/Talk- From here I usually take a moment to discuss a specific strategy or skill with the group. This may include vocabulary strategies, using nonfiction features, or inferring while we read. This means that I usually model skimming through the book and thinking out loud, followed by reading the first few pages to demonstrate and model the desired skill/strategy. Students are then encouraged to do the same, using post-it notes to record their thinking, as they whisper read or independently read to themselves.
Conference Time- At this point, I move from student to student and ask them to read to me. I may spend one to two minutes with the student and use this as a power conference. Looking at their notes and listening to how they are reading allows me to provide feedback and assess how they are working in that group. I record this information in a notebook as I move from student to student. After making the rounds, I then stop the group to discuss what we have been reading and recording so far. We also take time to compare our notes, which models strong note taking to each other.
Time Required- In total, we usually meet anywhere from 15 minutes to 25 minutes. It just depends on the length of the book and the focus of the meeting. If it is a shorter meeting, I might ask students to take the book with them to read with a partner at a later time.
Building On- After guided reading sessions are underway and established, I usually have students create a chart together based on the reading. This requires students to work together without me, so I utilize parent volunteers if possible. After the chart is completed, it is presented to the class and posted in various hallways around the school.
Finding the Time to Meet
It can be a real challenge teaching in the upper grades. So much content is expected to be covered, yet we don't want learning to feel stressful and rushed. In our room, we utilize three reading/writing blocks throughout the day. This structure allows me to use two of the blocks for reading and writing conferences and one block to meet for guided reading sessions. The last block is at the end of the day, so you may find me on the floor at 2:30 on a Friday afternoon meeting with a guided reading group. Click here to view a detailed schedule in our room.
Photos That Support Guided Reading
To learn more about our classroom, visit us here. | http://blogs.scholastic.com/3_5/2008/09/guided-reading.html |
There are several contaminants in wastewater, with organic pollutants playing the major role. Many kinds of organic compounds, such as PCBs, pesticides, herbicides, phenols, polycylic aromatic hydrocarbons (PAHs), aliphatic and hetercyclic compounds are included in the wastewater, and industrial and agricultural production as well as the people living could be the source of organic wastewater endangering the safety of the water resource . The wastewater of the farmland may contain high concentration of pesticides or herbicides; the wastewater of the coke plant may contain various PAHs; the wastewater of the chemical industry may contain various heterogeneity compounds, such as PCB, PBDE; the wastewater discharged by the food industry contains complex organic pollutants with high concentration of SS and BOD; and the municipal sewage contains different type of organic pollutants, such as oil, food, some dissolved organics and some surfactants. These organic pollutants in water can harm the environment and also pose health risks for humans.
1.2. Common poisonous substances in organic wastewater
The organic pollutants in the wastewater could be divided into two groups according to their biological degradation abilities. The organic pollutants with simple structures and good hydrophilicity are easy to be degraded in the environment. These organic pollutants, such as polysaccharide, methanol could be degraded by the bacteria, fungus and algae. However, some of them, such as acetone and methanol, could cause acute toxicity when existed in wastewater at a high concentration. On the other hand, the persistent organic pollutants, such as PAHs, PCBs, and DDT, are very slowly metabolized or otherwise degraded. Some of them, for example, the pesticides were widely used for several years. Although their concentration as well as the cute toxicity in the wastewater is lower than the soluble organic pollutant, they can be sequestered in sediment and exist for decades, and transport into the wastewater and then the food chain. The POPs are lipid soluble, and many of them mentioned above are carcinogenic, teratogenic, and neurotoxic. Since they are persistent, long way transported and toxic, these organic pollutants draw more attentions.
The classic poisonous substances in organic wastewater are as follow:
Water organic matter
Water organic matter is the genetic name of the organic compounds in the sediment and wastewater. Generated from the residues of the animal, plants and microorganisms, the water organic matters could be divided into two categories: one is non - humic, which is composed of the various organic compounds of organisms, such as protein, carbohydrate, organic acids, etc., the other is a special organic compounds named humus. Water organic matter could affect the physical and chemical properties of the water, and could also influence the self-purification, degradation, migration and transformation process in the water.
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. The main sources of formaldehyde are organic synthesis, chemical industry, synthetic fiber, dyestuff, wood processing and the paint industry emissions of wastewater. With a strong reducibility, formaldehyde could easily combine with a variety of material, and is easy to be together. Formaldehy is a stimulus to skin and mucous membrane. It could enter the central nervous of human body and cause retinal damage
Phenols
Phenols are a class of chemical compounds consisting of a hydroxyl group (-OH) bonded directly to an aromatic hydrocarbon group. The phenol in the wastewater mainly comes from the coking plant, refining, insulation material manufacturing, paper making and phenolic chemical plant. Phenol is known human carcinogen and is of considerable health concern, even at low concentration. Phenol also has potential to decrease the growth and the reproductive capacity of the aquatic organisms.
Nitrobenzene
Nitrobenzene is an organic compound with the chemical formula C6H5NO2. It is produced on a large scale as a precursor to aniline. In the laboratory, it is occasionally used as a solvent, especially for electrophilic reagents. Prolonged exposure may cause serious damage to the central nervous system, impair vision, cause liver or kidney damage, anemia and lung irritation. Recent research also found nitrobenzene as a potential carcinogenic substance.
PCBs
PCBs are biphenyl combined with 2 to 10 chlorine atoms. PCBs are widely used as dielectric and coolant fluids, for example in transformers, capacitors, and electric motors, and various kinds of PCBs could be found the wastewater of this factories. PCBs are carcinogenic, and could accumulate in adipose tissue, causing brain, skin and the internal organs disease, and influence nerve, reproductive and immune system. PCBs also have shown toxic and mutagenic effects by interfering with hormones in the body. PCBs, depending on the specific congener, have been shown to both inhibit and imitate estradiol.
PAHs are recalcitrant organic pollutants consisting of two or more fused benzene rings in linear, angular, or cluster arrangements. PAHs occur in oil, coal, and tar deposits, and PAHs in the aquatic system could come from accidently leaking, atmosphere deposition and contaminated sediment release. The concentration of PAHs, especially the PAHs with high molecular weight, in the water is usually low in the water owing to their hydrophobia property, but they are still among the most problematic substances as they could accumulate in the environment and threaten the development of living organisms because of their acute toxicity, mutagenicity or carcinogenity .
Organophosphorus pesticide
The wastewater of organophosphorus pesticide manufacturers often contains a high concentration of organophosphorus pesticide, intermedia productions and degradation productions, and the wastewater from the farmland could contain some of this pesticide since this substance could exist in the environment for a period of time. The discharge of water contained organophosphorus pesticide could cause serious environmental pollution. Some organophosphorus pesticides have acute poison on the people and livestock. In spite of the severe toxicity of the organophosphorus pesticide, it is easy to be degraded in the environment .
Petroleum hydrocarbons
The petroleum hydrocarbons in the water system mainly come from the industrial wastewater and municipal sewage. The industry, such as oil exploration, oil manufacture, transportation and refining could produce the wastewater with a mixture of various petroleum hydrocarbons. The petroleum hydrocarbons are toxic towards aquatic living things, and they could also aggravate the water quality by forming a layer of oil film, which could decrease the oxygen exchange of the air and water body.
Atrazine
Atrazine is the most widely used herbicide in conservation tillage systems, which are designed to prevent soil erosion. This chemical herbicide could stop pre- and post-emergence broadleaf and grassy weeds in dry farmland, and increase the production of the major crops . The wastewater contained atrazine mainly comes from the chemical industry manufacturing this product and the farmlands which are over loaded. This substance could remain in the environment for a period of time, and it has been detected in the surface water and groundwater of many countries and regions. Atrazine could volatilize at high temperature and release poisonous gas such as carbon monoxide, nitrogen oxides, which could irritate people's skin, eyes and respiratory tract. Besides, atrazine also has a potential cause of birth defects, low birth weights and menstrual problems when consumed at concentrations below federal standards.
1.3. Environmental hazards of organic wastewater
High mount of hydrophilic organic pollutants, such as organic matters, oil could consume a large amount of soluble oxygen. The acute toxicity and high quantity of oxygen demand could worsen the water quality and lead to great damage to the aquatic ecological system. However, their bad influence towards the environment will not last long, since they could easily be degraded by microorganisms.
The situation is different for the POPs, which have low water solubility, high accumulation capacity and potential carcinogenic, teratogenic, and neurotoxic properties. For example, many of the organochlorine pesticides cited above are carcinogenic, teratogenic, and neurotoxic. The dioxins and benzofurans are highly toxic and are extremely persistent in the human body as well as the environment. Several of the POPs, including DDT and its metabolites, PCBs, dioxins, and some chlorobenzene, can be detected in human body fat and serum years after any known exposures. Lindane (hexachlorocyclohexane), which was used for the treatment of body lice and as a broad-spectrum insecticide, could cause very high tissue levels, and could cause acute deaths when improperly used.
Many factors, such as the characters of the pollutants, the environmental factors (PH value, temperature etc.), aging process could affect the toxicity of the organic wastewater, and their long-term influence to the ecosystem deserve further investigation.
1.4. Monitoring analysis method of poisonous substances
Gross analysis
The amount of organic compounds in wastewater is generally evaluated by chemical oxygen demand (COD) test, biological oxygen demand (BOD) test, and (TOC) test.
The basis for the COD test is that nearly all organic compounds can be fully oxidized to carbon dioxide with a strong oxidizing agent under acidic conditions. The COD value is always measured by the acidic potassium permanganate method and potessium dichromate method, and could reflect the pollution degree of reducing matter in water, including ammonia and reducing sulfide, so in wastewater with high quantity of reducing matter, the COD value will overestimate the organic pollutants in the water.
BOD value is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The BOD value is most commonly expressed in milligrams of oxygen consumed per liter of sample during 5 days of incubation at 20 °C and is often used as a robust surrogate of the degree of organic pollution of water. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water.
TOC value is the mount of total carbon (water soluble and suspended in water) in the water. Using combustion during the assessment, this method could oxidize all the organic pollutants, and value reflects the amount of organic matter more directly than BOD5 or COD.
The COD, BOD and TOC test could quickly reflect the organic pollution in the wastewater, however, they can't reflect the kinds of organic matter and composition of the water, and therefore cannot reflect the total amount of the same total organic carbon pollution caused by different consequences.
Chromatography-mass spectrometry method
Chromatography-mass spectrometry method is an advanced method to separate and define the organic pollutants in the waste water. Spectrometry is the collective term for a set of laboratory techniques for the separation of mixtures. The separation is based on differential partitioning between the mobile and stationary phases. The structure diversity of different components in the wastewater results in a different retention on the stationary phase and thus changing the separation. The mobile phase of the chromatography can be gas or liquid, so the chromatography can be divided into gas chromatography (GC) and liquid chromatography (LC).
The mass spectrometer could ionize the organism and shoot it through an electric field. Since the electric field could bend the path (trajectory) of lighter molecules more than that of heavy molecules, the organic matter of different mass would strike at different position (the position is fixed for each organic matter) in the detector. This method could identify and quantify organic pollutants. The combination of chromatography and mass spectrometry could offer complete information on the type of organic pollutants in a sample and the concentration of each pollutant in the sample.
2. Biological treatment technology of organic wastewater
2.1. Principle of the biodegradation
Biodegradation is a process using microorganisms, fungi, green plants and their enzymes to remove the pollutants from natural environment or transform them harmless. Biodegradation could happen in nature world and is used in wastewater treatment in recent years since humanity strives to find sustainable ways to clean up contaminated water economically and safely.
2.2. Biodegradation of organic compounds
Chemical, physical and biological methods have been used to remove the organic compounds from the wastewater, and biological method has been paid much attention owing to its economic and ecologic superiority. The biodegradation rate and biodegradation degree of the organic substance partly depended on the characters of the substance. Some of the organic pollutants like organic matters, organophosphorus pesticide, which have relativity high water solubility and low acute toxicity, are bioavailable and easy to be degraded . However, for some POPs and xenobiotic organic pollutants, such as polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), heterocyclic compounds, pharmaceutical substances, which possess a higher bioaccumulation, biomagnification and biotoxicity properties, are reluctant to biodegradation in the nature condition. Organic material can be degraded aerobically with oxygen, or anaerobically, without oxygen .
2.3. Aerobic biodegradation
The principle of the aerobic biodegradation is as follow: oxygen is needed by degradable organisms in their degradation at two metabolic sites, at the initial attack of the substrate and at the end of respiratory chain . Bacteria and fungi could produce oxygenases and peroxidases they could help with the pollutant oxidization and get benefits from observing the energy, carbon and nutrient elements released during this process. A huge number of bacterial and fungal general possess the capability to release non-special oxidase and degrade organic pollutants. There are generally two types of relationships between the microorganism and organic pollutants: one is that the microorganisms use organic pollutant as sole source of carbon and energy; the other is that the microorganisms use a growth substrate as carbon and energy source, while another organic compound in the organic substrate which could not provide carbon and energy resource is also degraded, namely cometabolism.
The classic aerobic biodegradation reactors include activated sludge reactor and membrane bioreactor.
2.3.1. Activated sludge reactor
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans. This technique was invented by Ardern and Lockett at the beginning of last century and was considered as a wastewater treatment technique for larger cities as it required a more sophisticated mode of operation (Fig. 1) .
This process introduced air or oxygen into a mixture of primary treated or screened wastewater combined with organisms to develop a biological floc which reduces the organic content of the sewage, which is largely composed of microorganisms such as saprotrophic bacteria, nitrobacteria and denitrifying bacteria. With this biological floc, we could degrade the organic pollutant and bio-transform the ammonia in wastewater. Generally speaking, the process contained two steps: adsorption followed by biological oxidation.
The technique could effectively remove the organic matters, nitrogeneous matters, phosphate in the wastewater, when there is enough oxygen and hydraulic retention time. However, the contaminated water is always short of oxygen, which could cause sludge bulking, a great problem decrease the water quality of the effluent. The oxygen concentration could be increased by including aeration devices in the system, but research need to be done to find out the optimal value since aeration would cause an increase of the costs of the wastewater treatment plants. Researches are also required to deal with the excess activated sludge, the by-product of this process, with a relatively low cost.
2.3.2. Membrane bioreactor
Membrane bioreactor (MBR) is the combination of a membrane process like microfiltration or ultrafiltration with a suspended growth bioreactor, and is now widely used for municipal and industrial wastewater treatment. The scheme of the reactor is showed in Fig. 2 .
The Principle of this technique is nearly the same as activated sludge process, except that instead of separation the water and sludge through settlement, the MBR method uses the membrane which is more efficient and less dependent on oxygen concentration of the water.
The MBR has a higher organic pollutant and ammonia removal efficiency in comparison with the activated sludge process. Besides, the MBR processes is capable to treat waste water with higher mixed liquor suspended solids (MLSS) concentrations compared to activated sludge process, thus reducing the reactor volume to achieve the same loading rate.
However, membrane fouling greatly affects the performance of this technique, since fouling leads to significantly increase trans-membrane pressure, which increased the hydraulic resistance time as well as the energy requirement of this reactor. Alternatively frequent membrane cleaning and replacement is therefore necessary, but it significantly increases the operating cost.
2.4. Anaerobic biodegradation
Anaerobic degradation is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen. The principle of the anaerobic degradation is as follow: first, the insoluble organic pollutant brakes down the into soluble substance, making them available for other bacteria; second, the acidogenic bacteria convert the sugars and amino acid into carbon dioxide, hydrogen, ammonia and organic acid; third, the organic acids convert into acetic acid, ammonia, hydrogen and carbon dioxide; finally, the methanogens convert the acetic acid into hydrogen, carbon dioxide and methane, a kind of gaseous fuel .
Anaerobic degradation processes have always been considered to be slow and inefficient, in comparison to aerobic degradation. However, the anaerobic degradation not only decreases the COD and BOD in the waste water, but also produces renewable energy. Moreover, the anaerobic bacteria could break down some persistent organic pollutants, such as lignin and high molecular weight PAH, which show little or no reaction to aerobic degradation. Besides, anaerobic processes could treat the wastewater with high loads of easy-to-degrade organic materials (wastewaters of the sugar industry, slaughter houses, food industry, paper industry, etc.) efficiently and costly. These advantages make investigation and application of anaerobic microbial mineralization in organic polluted water important.
Generally speaking, anaerobic reactor could be divided into anaerobic activated sludge process and anaerobic biological membrane process. The anaerobic activated sludge process includes conventional stirred anaerobic reactor, upflow anaerobic sludge blanket reactor, and anaerobic contact tank. The anaerobic biological membrane process includes fluidized bed reactor, anaerobic rotating biological contactor, anaerobic filter reactor. Upflow anaerobic sludge blanket reactor and anaerobic filter reactor are selected as the representative of the two kinds of reactors mentioned above.
2.4.1. Upflow anaerobic sludge blanket reactor (UASB)
The UASB system was developed in 1970s. No carrier is used to in the UASB system, and liquid waste moves upward through a thick blanket of anaerobic granular sludge suspended in the system. As shown in Fig. 3, mixing of sludge and wastewater is achieved by the generation of methane within the blanket as well as by hydraulic flow. And the triphase separator (gas, liquid, sludge biomass) could prevent the biomass loss of the sludge through the gas emission and water discharge. The advantage of this system are that 1) it contains a high concentration of naturally immobilized bacteria with excellent settling properties, and could remove the organic pollutants from wastewater efficiently; 2) a high concentrations of biomass can be achieved without support materials which reduces the cost of construction. These advantages would increase the efficient and stable performance of this system .
2.4.2. Anaerobic biofilter
Anaerobic biofilter, so called anaerobic fixed film reactors, is a kind of high efficient anaerobic treatment equipment developed in 1960 s. These reactors use inert support materials to provide a surface for the growth of anaerobic bacteria and to reduce turbulence to allow unattached populations to be retained in the system (Fig 4). The organic matter of wastewater is degraded in the system, and produce methane gas, which will be released from the pool from the top .
The advantages of this system are as follow: 1) the filler provides a large surface area for the growth of the microorganisms, and the filler also increases hydraulic retention time of the wastewater; 2) the system provides a large surface area for the interaction between the wastewater and film; 3) the fact that microorganisms grow on the filler reduces the run of the degraders. These advantages could increase the efficiency of this treatment, and guarantee the water quality of the effluent. The backward of this system is that the system could be blocked when dealing with high concentration organic water, especially in the water inlet parts. And no simple and effective way for filter washing has been developed yet.
2.5. Combination of the aerobic and anaerobic biodegradation
Compared with the single anaerobic and aerobic reactors, the combination of the anaerobic and aerobic reactor is more efficient in organic pollutants degradation. The advantages of the combined system are as follow: 1) the anaerobic process could get rid of the organic matters and suspended solid from the wastewater, reduce the organic load of the aerobic degradation as well as the production of aerobic sludge, and finally reduce the volume of the reactors; 2) wastewater pretreated by anaerobic technology is more stable, indicating that anaerobic process could reduce the load fluctuation of the wastewater, and therefore decrease the oxygen requirement of the aerobic degradation; 3) the anaerobic process could modify the biochemical property of the wastewater, making the following aerobic process more efficient. Investigation showed that the wastewater from aerobic-anaerobic combined reactor are more stable and ready for degradation, indicating that this technical have a huge potential for application. The classic aerobic-anaerobic reactors include A/O reactor, A2/O reactor, oxidation ditch, constructed wetland.
Two classic aerobic biodegradation reactors, oxidation ditch and constructed wetland are introduced.
2.5.1. Oxidation ditch
The oxidation ditch is a circular basin through which the wastewater flows. Activated sludge is added to the oxidation ditch so that the microorganisms will digest the organic pollutants in the water. This mixture of raw wastewater and returned sludge is known as mixed liquor. The rotating biological contactors could add oxygen into the flowing mixed liquor, and they could also increase surface area and create waves and movement within the ditches. Once the organic pollutant has been removed from the wastewater, the mixed liquor flows out of the oxidation ditch. Sludge is removed in the secondary settling tank, and part of the sludge is pumped to a sludge pumping room where the sludge is thickened with the help of aerator pumps . Some of the sludge is returned to the oxidation ditch while the rest of the sludge is sent to waste.
The oxidation ditch is characterized by simple process, low maintain consumption, steady operation, and strong shock resistance. The effluent of the system has high water quality effluent with low concentration of organic pollutants, nitrogen and phosphorus. However, the problems of this reactor, such as sludge expansion, rising sludge and foam, are important factors which confines the development of this technique.
2.5.2. Constructed wetland
A constructed wetland is an artificial wetland which could wetlands act as a biofilter, removing sediments and pollutants such as heavy metals and organic pollutants from the water. Constructed wetland is a combination of water, media, plants, microorganisms and other animals. Constructed wetlands are of two basic types: subsurface-flow and surface-flow wetlands .
Physical, chemical, and biological processes combine in wetlands to remove contaminants from wastewater. Besides absorbing heavy metals and organic pollutants (especially POPs) on the filler of the constructed wetland, plants can supply carbon and other nutrients such as nitrogen through their roots to for the growth and reproduction of the microorganisms. Plants could also pump oxygen to form an aerobic and anaerobic area in the deep level of constructed wetland to assist the breaking down of organic materials. The major reactor in constructed wetland was supposed to be microorganisms, and microorganisms and natural chemical processes are responsible for approximately 90 percent of pollutant removal, while, the plants remove about 7-10 percent of pollutants. In addition to organic pollutants, this device could remove the nitrogen and phosphorous in the wastewater and prevent eutrophication.
As an economical, easy management and ecological friendly reactor, constructed wetland is supposed to be a promising technique to treat the wastewater in developing country. However, this technique was not widely used up to now for 1) the plants couldn’t adapt to heavy contaminated wastewater, which strikes its application scope; 2) the device of this technique demands large area of land; 3) the efficiency of this device relativity lower than other biological device such as activated sludge process and membrane bioreactor. Thus, efforts should be made in plants selection, device structure modification and multiple devices combination to enhance the adaption and efficiency of this technique.
3. Chemical oxidation technologies
Nowadays, due to the increasing presence of molecules, refractory to the microorganisms in the wastewater streams, the conventional biological methods cannot be used for complete treatment of the effluent and hence, introduction of newer technologies to convert it into less harmful or lower chain compounds which can be then treated biologically, has become imperative. Chemical oxidation technology is one of these newer technologies which use chemical oxidant (H2O2, O3, ClO2, K2MnO4, K2FeO4 and so on) oxide pollutant to slightly toxic, harmless substances or transform it into manageable form. However, Chemical oxidation technologies constitute the use of oxidizing agents such as ozone and hydrogen peroxide, exhibit lower rates of degradation. Therefore, advanced oxidation processes (AOPs) with the capability of exploiting the high reactivity of hydroxyl radicals in driving oxidation have emerged a promising technology for the treatment of wastewaters containing refractory organic compounds. Several technologies like Fenton, photo-Fenton, wet oxidation, ozonation, photocatalysis, etc. are included in the AOPs and their main difference is the source of radicals.
3.1. Chemical oxidation technologies under normal temperature and pressure
This part aims at highlighting three different oxidation processes operating at ambient conditions viz. Fenton’s chemistry (belonging to the class of AOPs) and ozonation, use of hydrogen peroxide (belonging to the class of chemical oxidation technologies).
3.1.1. Classification and principle
3.1.1.1. Hydrogen peroxide
Hydrogen peroxide (H2O2 ) is an environment friendly oxide which could oxidate organic pollutants efficiently and economically. The standard reduction potentials (1.77V, 0.88v) of hydrogen peroxide imply that it is a strong oxidant in both acidic and basic solutions . It can oxidize many kinds of organic contaminants in wastewater directly. The very slow decomposition rate of hydrogen peroxide in the drinking water treatment, with mild operation conditions, can ensure a longer disinfection. Also, it can be utilized as a dechlorination agent (reductant) without organic halogen compounds production. Therefore, the hydrogen peroxide is the ideal drinking water pre-oxidant and disinfectant.
H2O2 +2H+ +2e−→ 2H2O E◦= 1.77V
HO2− +H2O + 2e−→ 3OH− E◦= 0.87V
However, considering for the removal of organic compounds in wastewater, the reactivity of hydrogen peroxide is generally low and largely incomplete due to kinetics, in particular in acidic media. It can be enhanced by homogeneous and/or heterogeneous catalysts, the progress named wet hydrogen peroxide catalytic oxidation (WHPCO). WHPCO operates at temperatures in the 20-80℃ range and atmospheric pressure.
3.1.1.2. Fenton
The Fenton's process has its origin in the discovery reported in 1894 that ferrous ion strongly promotes the hydrogen peroxide oxidation of tartaric acid. The mechanism of the Fenton's process is quite complex, and some papers can be found in the literature where tens of equations are used for its description. Nevertheless, it can be summarized by the following steps: first, a mixture of H2O2 and ferrous iron in acidic solution generates the hydroxyl radicals which will subsequently attack the organic compounds present in the solution .
Fe2++H2O2→Fe3++HO−+HO•
As iron (II) acts as a catalyst, it has to be regenerated, which seems to occur through the following scheme:
Fe3++H2O2↔Fe-OOH2++H+
Fe-OOH2+→Fe2++HO2•
The important mechanistic feature of the Fenton reaction is that in the outer-sphere single electron transfer from Fe2+ to H2O2 and generates hydroxyl radicals and hydroxide anions. Hydroxyl radicals are after fluorine atoms the most oxidizing chemical species. They are extremely powerful species to abstract one electron from an electron rich organic substrate or any other species present in the medium to form hydroxide anion. The oxidation potential of hydroxyl radicals has been estimated as +2.8 and +2.0V at pH 0 and 14, respectively. The high reactivity of HO• ensures that it will attack a wide range of organic compounds. Fenton reaction gives rise to CO2 and the heteroatoms also form the corresponding oxygenated species such as NOx, SOx and POx, meaning that the carbons and heteroatoms of the organic substrate are converted to inorganic species. Equations illustrate the cyclic processes occurring in Fenton chemistry under aerobic conditions leading to the formation of CO2.
RH+HO•→R• + H2O
R• +Fe3+→ R+ +Fe2+
R+ +H2O → ROH + H+
R• +Fe2+→ products + Fe3+
R• +O2→ ROO•
R• + •OOH → RO• + •OH
ROO• +RH → ROOH + R•
ROO• +Fe2+→ products + Fe3+
ROO• +Fe3+→ products + Fe2+
The performance of Fenton oxidation application to wastewater treatment was based on the following parameters: operating pH, amount of ferrous ions, concentration of hydrogen peroxide, initial concentration of the pollutant, type of buffer used for pH adjustment, operating temperature and chemical coagulation. The optimum pH has been observed to be 3 in the majority of the cases. The pollutant removal efficiency increases with an increase in the dosage of ferrous ions and hydrogen peroxide. However, care should be taken while selecting the dosage, for high dosage leasing environmental question and high treatment cost. The optimum dosage is available in the open literature or required to establish in laboratory scale studies under similar conditions.
The conventional Fenton reaction that hydrogen peroxide in conjunction with an iron(II) salt to produce high fluxes of hydroxyl radicals is homogeneous catalytic reaction. Therefore, the application of conventional Fenton reaction is complicated by the problems typical of homogeneous catalysis, such as catalyst separation, regeneration, etc. It is necessary to control pH carefully to prevent precipitation of iron hydroxide. Thus, heterogeneous catalysts Fenton reaction, i.e., solids containing transition metal cations (mostly iron ions) have been developed and tested .
3.1.1.3. Ozonation
Ozone is one of the most powerful oxidants with an oxidation potential of 2.07 V. In acidic conditions, ozone undergoes selective electrophilic attack which occurs at particular parts of complexing agent with high electronic density. Under alkaline environment, ozone is catalyzed by OH- in basic conditions to intermediate compounds such as superoxide, HO radicals and HO2 radicals which are highly reactive. Apart from pH, the degradation of target compounds in the liquid phase corresponds to the amount and form (species) of oxidants present in a reactor .
O3+OH-→HO2-+O2
O3+OH-→HO•+O3-
O3+HO2-→HO2•+O3•
The applications of ozonation for water treatment offer various advantages. Due to its short half-life of less than 10 min, the oxidant degrades most of pollutants rapidly. However, at pH 10, the half-life of ozone in solutions is less than 1 min. As a result, ozonation extensively consumes energy, thus reducing its treatment efficiency. Due to the improvement in ozone production from pure oxygen and the increase of its concentration in the feeding gas, an ozone generation with less cost may be economically attractive.
The performance of ozonation application to wastewater treatment was based on the following parameters: operating pH, ozone partial pressure, contact time and interfacial area, presence of radical scavengers, operating temperature, presence of catalyst, combination with other oxidation processes.
Very low reaction rates have been observed for the degradation of complex compounds or mixture of contaminants by ozonation alone. Catalyst such as BST catalyst TiO2 fixed on alumina beads, Fe (II), Mn (II) can be used to increase the degradation efficiency. Heterogeneous catalytic ozonation has received increasing attention in recent years due to its potentially higher effectiveness in the degradation and the mineralization of refractory organic pollutants and a lower negative effect on water quality. The major advantage of a heterogeneous over a homogeneous catalytic system is the ease of catalytic retrieval from the reaction media. Results suggest that catalytic ozonation with MnOx/MZ, CoOx/MZ and CuOx/Al2O3 is a promising technique for the mineralization of refractory organic compounds in water .
3.1.2. Reactors
3.1.2.1. Typical reactor used for Hydrogen peroxide
Introduction of hydrogen peroxide into the waste stream is critical due to lower stability of hydrogen peroxide. An addition point should give large residence time of H2O2 in the pollutant stream, but due to the practical constraints and poor mixing conditions, it is not always possible to inject H2O2 in line and an additional holding tank is required. The simplest, faster and cheapest method for injection of hydrogen peroxide is gravity feed system. Pump feed systems can also be used, but it requires regular attention.
Figure 7 reports a simplified flow diagram of the WHPCO technology for the treatment of olive oil milling waste water using Fe-ZSM-5 solid catalysts. H2O2 is added progressively at the top of a fixed bed catalytic reactor (before a static mixer), in order to maximize its local concentration. An iron solution is added on the top of the reactor to maintain catalyst activity constant. The feed solution is recirculated to and from a tank in order to have good turbulence in the catalyst bed, but also to guarantee the necessary total residence time to obtain the required level of removal of phytotoxic chemicals.
3.1.2.2. Typical reactor used for fenton oxidation
A batch Fenton reactor essentially consists of a nonpressurized stirred reactor with metering pumps for the addition of acid, base, a ferrous sulfate catalyst solution and industrial strength (35-50%) hydrogen peroxide. The reactor vessel should be coated with an acid-resistant material, because the Fenton reagent is very aggressive and corrosion can be a serious problem. pH of the solution must be adjusted at 6, usually iron hydroxide is formed. For many organic pollutants, the ideal pH for the Fenton reaction is between 3 and 4, and the optimum catalyst to peroxide ratio is usually 1:5 wt/wt. Addition of reactants are done in the following sequence: dilute sulfuric acid catalyst in acidic solutions, pH adjusting agent (adjustment of pH at 3-4) and lastly added hydrogen peroxide slowly. Effluent of the Fenton reactor (Oxidation tank) is fed into a neutralizing tank for adjusting the pH (adjustment of pH at 9), then the stream followed by a flocculation tank and a solid-liquid separation tank for removing the precipitate. A schematic representation of the Fenton oxidation treatment has been shown in Figure 8 .
3.1.2.3. Typical reactor used for ozonation
Ozone transfer efficiency should be maximized by increasing the interfacial area of contact (reducing the bubble size by using small size ozone diffusers such as porous disks, porous glass diffusers, ceramic membranes) and increasing the contact time between the gas and the water (increase the depths in the contactor, optimum being 3.7 to 5.5 m) .
3.1.3..Application
3.1.3.1. Hydrogen peroxide
Hydrogen peroxide has been used in the industrial effluent treatment for detoxification of cyanide, nitrite and hypochlorite, for the destruction of phenol aromatics, formaldehyde, removal of sulfite, thiosulfate and sulfide compounds.
However, the application of hydrogen peroxide alone for wastewater treatment applications present major problems such as very low rates for applications involving complex materials, stability of H2O2 and mass transfer limitations. Hence, use of hydrogen peroxide alone does not seem to be a recommendable option for industrial wastewater treatment.
WHPCO process has been proposed for a variety of agro-food and industrial effluents: removal of dyestuffs from textile, treat sewage sludge, purify wastewater from pharmaceutical and chemical production, dumping site, or from cellulose production and pre-treat water streams from food-processing industries (olive oil mills, distilleries, sugar refineries, coffee production, tanneries, etc.) .
3.1.3.2. Fenton
Fenton process can significantly remove recalcitrant and toxic organic compounds, and increase the biodegradability of organic compounds. Leachate quality in terms of organic content, odor, and color can be greatly improved following Fenton treatment. Fenton’s reagent has been used quite effectively for the treatment and pre-treatment of leachate from composting of different wastes. Reported COD removal efficiencies range from 45% to 85%, and reported final BOD5/COD ratio can be increased from less than 0.10 initially to values ranging from 0.14 to more than 0.60, depending on leachate characteristic and dosages of Fenton reagents. Color and odor in leachate can also be reduced considerably. The decolorization efficiency is as high as 92% in Fenton treatment of a mature leachate. The optimal conditions for Fenton reaction were found at a ratio [Fe2+]/[COD] equal to 0.1. Both leachates were significantly oxidized under these conditions in terms of COD removal 77-75% and BOD5 removal 90-98%. Fenton's reagent was found to oxidize preferably biodegradable organic matter of leachate . Pirkanniemi et al. (2007) tested the Fenton’s oxidation to degrade complexing agents such as N-bis[2-(1,2-dicarboxyethoxy) ethyl)] glysine (BCA5), N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid (BCA6) and EDTA from bleaching wastewater. It was reported that an almost complete removal of EDTA was attained at its concentration of 76 mM.
3.1.3.3. Ozonation
Ozone can be used for treatment of effluents from various industries relating to pulp and paper production (bleaching and secondary effluents), Shale oil processing, production and usage of pesticides, dye manufacture, textile dyeing, production of antioxidants for rubber, pharmaceutical production etc.
Beltrán et al. (2006) reported that ozonation alone improved the removal of succinic acid up to 65% at pH 7 with an initial concentration of 339 mM. Decolorization of dye Methylene Blue can be achieved by ozonation. The COD of basic dyestuff wastewater was reduced to 64.96% and decolorization was observed under basic conditions (pH 12), complete Methylene Blue degradation occurring in 12 min. The decolorization time decrease linearly with the increase in ozone concentration. For example, increasing ozone concentration from 4.21 g/m3 to 24.03 g/m3 in the gas phase reduces the decolorization time of 400 mg/L dye concentration by about 88.43% .
3.2. Chemical oxidation technologies under high temperature and pressure
3.2.1. Classification and principle
3.2.1.1. Wet air oxidation (WAO)
WAO is based on the oxidizing properties of air’s oxygen. Typical conditions for wet oxidation range from 180 ◦C and 2 MPa to 315 ◦C and 15 MPa. Residence times may range from 15 to 120 min, and the chemical oxygen demand (COD) and total organic carbon (TOC) removal may typically be about 75-90%. Insoluble organic matter is converted to simpler soluble organic compounds without emissions of NOx, SO2, HCl, dioxins, furans, fly ash, etc.
O2 +4H+ +4e−→ 2H2O E◦ = +1.23V
O2 +2H2O + 4e−→ 4OH− E◦ = +0.40V
3.2.1.2. Catalytic wet air oxidation (CWAO)
Organic pollutant is impossible to obtain a complete mineralization of the waste stream by WAO, since some low molecular weight oxygenated compounds (especially acetic and propionic acids, methanol, ethanol, and acetaldehyde) are resistant to oxidation. Organic nitrogen compounds are easily transformed into ammonia, which is also very stable in WAO conditions. Therefore, WAO is a pre-treatment of liquid wastes which requires additional treatment. The use of catalysts (WACO) allows to use milder reaction conditions but especially to promote conversion of the reaction intermediates (for example, acetic acid and ammonia) which are very difficult to convert in the absence of catalysts, as mentioned above.
Though it varies with type of wastewater, the operating cost of CWAO is about half that of non-catalytic WAO due to milder operating conditions and shorter residence time. Although the homogenous catalysts, e.g. dissolved copper salts, are effective, an additional separation step is required to remove or recover the metal ions from the treated effluent due to their toxicity, and accordingly increases operational costs. Thus, the development of active heterogeneous catalysts has received a great attention because a separation step is not necessary. Various solid catalysts including noble metals, metal oxides, and mixed oxides have been widely studied for the CWAO of aqueous pollutants. To further decrease the reaction temperature and pressure, intensive oxidants are added and form Wet Peroxide Oxidation (WPO), WHPCO is belonging to WPO.
3.2.2. Reactors
3.2.2.1. WAO reactors
The experimental set up consisted mainly of a reactor and a condenser. It was equipped with suitable measuring devices, such as thermocouple, rotameter and pressure gauge. The material of construction for reactor is titanium. The top of the reactor is connected to a reflux condenser with a stainless steel flange. The reactor was equipped with a heating jacket and a gas sparger. The gas (air or oxygen) entered the reactor through the titanium sparger. Air or oxygen bubbled out through the sparger at high speed and thus ensured proper agitation .
3.2.2.2. CWAO reactors
Homogeneous catalysts for CWAO are usually transition metal cations, such as Cu and Fe ions. Industrial homogenous CWAO processes have been developed such as the Ciba-Geigy/Garnit process working at high temperature (300 ◦C), and the LOPROX Bayer process working with oxygen below 200 ◦C in the presence of iron ions. Common two-phase reactor types used in homogeneous CWO include bubble columns, jet-agitated reactors, and mechanically stirred reactor vessels.
Figure 9 reports a simplified flow diagram of a WACO process which consists mainly of a high-pressure pump, an air or oxygen compressor, a heat-exchanger, a high-pressure (fixed bed) reactor and a downstream separator. The simplest reactor design is usually a cocurrent vertical bubble column with a height-todiameter ratio in the range of 5-20. A catalytic unit for the treatment of the off-gas is also typically necessary .
3.2.3..Application
WAO is not used as a complete treatment method, but only as a pretreatment step where the wastewater is rendered to nontoxic materials and the COD is reduced for the final treatment. For integrated WAO-biological treatment process, more detailed studies concerning the WAO pretreatment step are necessary for the design of a rational and efficient integrated process. The WAO process has been subjected to numerous investigations by researchers in the past decades as a pretreatment step before the biological treatment [29-32].
Pretreatment of Afyon (Turkey) alcaloide factory wastewater, a typical high strength industrial wastewater (COD= 26.65 kg/m3; BOD5= 3.95 kg/m3) was carried out by WAO process. Experimental results indicated that over 26% COD removal of the wastewater could be achieved in 2.0 h of reaction time at 150°C; 0.65 MPa and with an airflow rate of 1.57×105 m3/s. BOD5/COD ratio is increased from 0.15 to 0.4. The experimental data also revealed that the pressure and temperature effects on the COD removal were important. The COD removal was observed to increase with an increase in both pressure and temperature. Maximum COD removal was obtained at around pH 7.0 .
As considering for using the CWAO process to treat Afyon (Turkey) alcaloide factory wastewater, results indicate that the presence of catalyst increases the COD removal. The COD removal for 2.0 h reaction time increased from 25.7% without catalyst to 33.2% with 0.25 kg/m3 catalyst. While the BOD5/COD ratio is increased to over 0.4 .
CWAO makes a promising technology for the treatment of refractory organic pollutants (phenolic compounds, carboxylic acids, N-containing compounds) in industrial wastewaters, such as Olive oil mill wastewater, Kraft bleaching plant effluents, Coke plant wastewater, Textile wastewater, Alcohol-distillery wastewater, Landfill leachate, Pulp and paper bleaching liquor, Heavily organic halogen polluted industrial wastewater and so on .
4. Adsorption technology
4.1. Principle of adsorption technology
Adsorption offers a cleaner technology, free from sludge handling problems and produces a high quality effluent. Over the last few decades, adsorption has gained importance as an effective purification and separation technique used in water and wastewater treatment. Adsorption is the process by which a solid adsorbent can attach a component dissolved in water to its surface and form an attachment via physical or chemical bonds, thus removing the component from the fluid phase. Adsorption is used extensively in industrial processes for many purposes of separation and purification. The removal of metals, coloured and colourless organic pollutants from industrial wastewater are considered an important application of adsorption processes using suitable adsorbents.
Adsorption is nearly always an exothermic process. We can distinguish between 2 types of adsorption process depending on which of these two force types plays the bigger role in the process. Adsorption processes can be classified as either physical adsorption (van der Waals adsorption) or chemisorption (activated adsorption) depending on the type of forces between the adsorbate and the adsorbent.
Physical adsorption occurs quickly and may be mono-molecular (unimolecular) layer or monolayer, or 2, 3 or more layers thick (multi-molecular). As physical adsorption takes place, it begins as a monolayer. It can then become multi-layer, and then, if the pores are close to the size of the molecules, more adsorption occurs until the pores are filled with adsorbate. Accordingly, the maximum capacity of a porous adsorbent can be more related to the pore volume than to the surface area.
Chemisorption involves the formation of chemical bonds between the adsorbate and adsorbent is a monolayer, often with a release of heat much larger than the heat of condensation. Chemisorption from a gas generally takes place only at temperatures greater than 300 ◦C, and may be slow and irreversible. Most commercial adsorbents rely on physical adsorption; while catalysis relies on chemisorption.
4.2. Development of adsorption materials
4.2.1. Activated carbon
Activated carbon is by far the most common adsorbent used in wastewater treatment. Since, during adsorption, the pollutant is removed by accumulation at the interface between the activated carbon (absorbent) and the wastewater (liquid phase) the adsorbing capacity of activated carbon is always associated with very high surface area per unit volume. Activated carbon can be manufactured from carbonaceous material, including coal (bituminous, subbituminous, and lignite), peat, wood, or nutshells (i.e., coconut). The manufacturing process consists of two phases, carbonization and activation. The carbonization process includes drying and then heating to separate by-products, including tars and other hydrocarbons, from the raw material, as well as to drive off any gases generated. The carbonization process is completed by heating the material at 400–600°C in an oxygen-deficient atmosphere that cannot support combustion. Powdered activated carbon is made up of crushed or ground carbon particles, 95–100% of which will pass through a designated mesh sieve or sieves. Granular activated carbon can be either in the granular form or extruded. It is designated by sizes such as 8×20, 20×40, or 8×30 for liquid phase applications and 4×6, 4×8 or 4×10 for vapor phase applications.
4.2.2..Activated alumina
Activated alumina had been used in the treatment of wastewater and its adsorption capability for the removal of both organic and inorganic compounds was found to be favoured by a specific surface area, pore structure, ionic strength and chemical inertness. It can be produced from the mixtures of amorphous and gamma alumina prepared by the dehydration of Al(OH)3 under low-temperatures of 300-600◦C, with surface areas in the range of 250-350 m2/g.
Research conducted on the use of microporous alumina pillared montmorillonite (clay) and mesoporous alumina aluminium phosphate as adsorbents had shown successful removal of fluoride, arsenic, selenium, beryllium, 2,4-chlorophenol, 2,4,6- trichlorophenol, pentachlorophenol, and also pesticides such as: molinate, propazine and atrazine from waster water. The removal efficiency of the pillared clay material for the herbicide was found to be higher than that of the mesoporous aluminium phosphate due to the substitution of the alkyl lateral chains of the aluminium phosphate during the sorption of s-triazines and the increase of P/Al ratio during the adsorption of propachlor.
4.2.3. Zeolites
The drawback suffered by activated carbon due to its high regeneration cost and production cost has lead to the application of zeolites as an alternative adsorbent. Zeolites are a group of natural or synthetic hydrated aluminosilicate minerals which contain both alkaline and alkali-earth metals. It has been used as an adsorbent, molecular sieve, ion-exchangers and catalysts in the past decades, because their chemical properties and large effective surface area gives them superior adsorptive qualities. There are several types of zeolites such as MCM-22, ZSM-5, ZSM-22, BETA, and Y. Their adsorption equilibrium had been studied and showed that the synthetic zeolites have higher adsorption capacity than the natural zeolites for the removal of ink, dyes and polluted wastewater.
4.2.4. Peat
Peat and other biomass materials have been used previously in the treatment of wastewater containing heavy metals and organic compounds. Peat is a yellow to dark brown residue, which occurs during the first stage of coal formation. It is composed of partly carbonizing materials such as decayed trees and peats bogs that have accumulated in water–saturated environments and swamps. The main constituents of peat moss are lignin, humic acid and cellulose. In addition, the surface functional groups of peat include aldehydes, carboxylic acids, ketones, alcohols, ethers and phenolic hydroxides, which are all involved in the adsorption of pollutants. In addition, its polar nature is responsible for its specific adsorption potential for dissolved metals and polar organic compounds.
4.2.5. Natural materials
Natural materials that are available in large quantities, or certain waste products from industrial or agricultural operations, may have potential as inexpensive adsorbents. The abundance, availability, and low cost of agricultural byproducts make them good adsorbents for the removal of various pollutants from wastewaters. Agricultural waste biomass currently is gaining importance. In this perspective rice husk, which is an agro-based waste, has emerged as an invaluable source for the utilization in the wastewater treatment. Rice husk contains ∼20% silica, and it has been reported as a good adsorbent for the removal of heavy metals, phenols, pesticides, and dyes. The adsorptive capacity of rice husk silica had been evaluated by Grisdanurak et al. and its adsorption capacity for chlorinated volatile organic compounds was found to be higher than that of commercial mordenite and activated carbons. It has been utilized for solving disposal problems and also as an adsorbent in treating organic wastewaters. The adsorption potential of this biomass for adsorbing phenol from aqueous solution was found to be depended on the pH, contact time and the initial phenol concentration. This result shows that phenol was adsorbed to a lesser extent at higher pH values. Phenol forms salts, which readily ionize leaving negative charge on the phenolic group while, its present on the adsorbent prevents the removal of phenolateions. In addition, the percentage adsorption of phenol for this test also decreases as the initial phenol concentration increases. The adsorption capacity determined for this test was 0.886 mg/g for phenol and the equilibrium data was fitted successfully by the Freundlich model .
4.2.6. Polymeric
Polymeric adsorbents are non-functionalized organic polymers which are capable of removing organics from water. The principle is quite simple. Wastewater is passed through a column containing the polymeric adsorbent. The organic materials are retained on the resin while water and some simple salts pass through. When the resin is fully loaded, the organics are stripped from the resin with solvents or caustic. The organic material may be concentrated by orders of magnitude in some cases. The following recommendations are those being used at the present time. The regenerants used are not the only ones possible. The choice of regenerant (solvent) usually depends on the availability at the particular location.
4.3. Adsorption equipment and their applications
Granular activated carbon systems are generally composed of carbon contactors, virgin and spent carbon storage, carbon transport systems, and carbon regeneration systems. The carbon contactor consists of a lined steel column or a steel or concrete rectangular tank in which the carbon is placed to form a “filter” bed. A fixed bed downflow column contactor is often used to contact wastewater with granular activated carbon. Wastewater is applied at the top of the column, flows downward through the carbon bed, and is withdrawn at the bottom of the column. The carbon is held in place with an underdrain system at the bottom of the contactor. Provisions for backwash and surface wash of the carbon bed are required to prevent buildup of excessive headloss due to accumulation of solids and to prevent the bed surface from clogging.
There are two basic types of water filters: particulate filters and adsorptive/reactive filters. Particulate filters exclude particles by size, and adsorptive/reactive filters contain a material (medium) that either adsorbs or reacts with a contaminant in water. The principles of adsorptive activated carbon filtration are the same as those of any other adsorption material. The contaminant is attracted to and held (adsorbed) on the surface of the carbon particles. The characteristics of the carbon material (particle and pore size, surface area, surface chemistry, etc.) influence the efficiency of adsorption .
The characteristics of the chemical contaminant are also important. Compounds that are less water-soluble are more likely to be adsorbed to a solid. A second characteristic is the affinity that a given contaminant has with the carbon surface. This affinity depends on the charge and is higher for molecules possessing less charge. If several compounds are present in the water, strong adsorbers will attach to the carbon in greater quantity than those with weak adsorbing ability.
5. Other technologies
5.1. Solvent extraction
Solvent extraction is a common form of chemical extraction using organic solvent as the extractant. It is commonly used in combination with other technologies, such as solidification/stabilization, incineration, or soil washing, depending upon site-specific conditions. Solvent extraction also can be used as a stand alone technology in some instances. Organically bound metals can be extracted along with the target organic contaminants, thereby creating residuals with special handling requirements. Traces of solvent may remain within the treated soil matrix, so the toxicity of the solvent is an important consideration.
Solvent extraction method has many advantages, such as less investment in equipment, easy to operate and lower consumption. Moreover, the major pollutants can be effectively recycled by solvent extraction method. The extraction method is widely used in a variety of organic waste, such as phenol, organic carboxylation acids, organic phosphorus nitrogen, organic sulfonic acid, organic amine, etc. Solvent extraction has been shown to be effective in treating sediments, sludges, and soils containing primarily organic contaminants such as PCBs, VOCs, halogenated solvents, and petroleum wastes. The process has been shown to be applicable for the separation of the organic contaminants in paint wastes, synthetic rubber process wastes, coal tar wastes, drilling muds, wood-treating wastes, separation sludges, pesticide/insecticide wastes, and petroleum refinery oily wastes.
Adopting solvent extraction treatment technology for organic wastewater, the most important thing is to choose the right process flow specifically for specially appointed pollution. For the general flow, most difficult degradation of the pollutants are removed after the process of solvent extraction. Crafts residue mainly contain some pollutants which are not extractive and dissolved, and they would meet the emissions standards through the secondary treatment regeneration (such as biochemistry, chemical oxidation, etc.).
5.2. Incineration
Incineration involves the combustion of the organic (carbon-containing) solids present in wastewater solids and biosolids to form carbon dioxide and water. The temperature in the combustion zone of furnaces is typically 1023K to 1143K. The solids that remain at the end of the process are an inert material commonly known as ash. Either undigested wastewater solids or biosolids may be incinerated. The terms thermal oxidation and combustion may be used interchangeably with incineration.
Incineration takes advantage of the fuel value of wastewater treatment residual solids (referred to as sludge) and biosolids. In some cases, the energy recovered from this process has been used in heat exchangers and waste heat boilers to save on energy use at
the wastewater treatment plant. For example, in Montreal, a portion of the biosolids generated at the facility are incinerated, while the remaining portion is pelletized. Waste heat from the biosolids that are incinerated is used in the thermal dryers that produce fertilizer pellets. In Europe, there is a trend to use biosolids as a fuel source in dedicated power generation facilities. In addition, incineration results in a large reduction in volume and mass in comparison to other alternatives and options. The mass of solids in the ash that results from the inceration process is approximately 10% of that of the biosolids fed into the incinerator. This reduces the mass and volume requiring disposal.
There are two common incineration technologies for wastewater solids and biosolids: fluidized bed incinerators and multiple hearth incinerators. Fluidized bed incinerators are steel cylinders lined with refractory bricks to withstand the high operating temperatures of the unit. Multiple hearth incinerators consist of a series of refractory brick hearths, stacked vertically. A rotating shaft through the centre of the hearths supports rake arms for each hearth, thereby facilitating drying and incineration. Solids are usually fed through at the top hearth and are directed to successive inner or outer dropholes as they move down through the hearths. Most of the ash is discharged from the bottom hearth.
Over the years, incineration technologies have evolved considerably and regulations and procedures have continually been enhanced to protect human and animal health and the environment. A considerable amount of scientific study has been undertaken to support the development of the regulations, and ongoing research contributes to the continuous improvement of this practice. However, some segments of the public still have concerns that incineration may be unsafe because of perceptions related to outdated technology and to experiences with incineration of other materials such as hazardous waste, municipal solid waste and medical waste.
5.3. Photocatalysis
To date, the most widely applied photocatalyst in the research of water treatment is the Degussa P-25 TiO2 catalyst. This catalyst is used as a standard reference for comparisons of photoactivity under different treatment conditions. The fine particles of the Degussa P-25 TiO2 have always been applied in a slurry form. This is usually associated with a high volumetric generation rate of reactive oxygen species as proportional to the amount of surface active sites when the TiO2 catalyst in suspension. On the contrary, the fixation of catalysts into a large inert substrate reduces the amount of catalyst active sites and also enlarges the mass transfer limitations. Immobilization of the catalysts results in increasing the operation difficulty as the photon penetration might not reach every single surface site for photonic activation. Thus, the slurry type of TiO2 catalyst application is usually preferred. With the slurry TiO2 system, an additional process step would need to be entailed for post-separation of the catalysts. This separation process is crucial to avoid the loss of catalyst particles and introduction of the new pollutant of contami-nation of TiO2 in the treated water . The catalyst recovery can be achieved through process hybridization with conventional sedimentation , cross-flow filtration or various membrane filtrations .
Natural clays have been used intensively as the support for TiO2 owing to their high adsorption capacity and cost-effectiveness. The use of the photocatalytic membranes has been targeted owing to the photocatalytic reaction can take place on the membrane surface and the treated water could be continuously discharged without the loss of photocatalyst particles. To broaden the photoresponse of TiO2 catalyst for solar spectrum, various material engineering solutions have been devised, including composite photocatalysts with carbon nanotubes , dyed sensitizers , noble metals or metal ions incorporation , transition metals and non-metals doping .
5.4. Ultrasonic
High-frequency ultrasound is a mechanical wave, with a shorter wavelength, the energy concentration characteristics, its application mainly on the basis of energy major, along a straight line features of these two started. The 20th century, the early 90s, some scholars have begun to study abroad, such as the ultrasonic degradation of organic pollutants in water. Ultrasound technology is simple, efficient, non-polluting or less polluting characteristics, in recent years the development of a new type of water treatment technology. It combines advanced oxidation, pyrolysis, supercritical oxidation technology in one, and the degradation of speed, be able to water of harmful organic compounds into CO2, H2O, inorganic ions or organic toxic than the original readily biodegradable organic matter, and therefore in dealing with difficult Bio-degradation of organic contaminants has significant advantages.
6. Treatment processes of various industrial organic wastewaters
6.1. Coking plant
Coke, produced by the pyrolysis of natural coals, is an indispensable material for most of the metallurgical facilities. During coking, coal decomposes into gases, liquid and solid organic compounds. Coke wastewater contains high concentration of ammonia, phenols, thiocyanate, cyanide and lower amounts of other toxic compounds, such as polyaromatic hydrocarbons (PAHs), e.g. naphthalene, and heterocyclic nitrogenous compounds, e.g. quinoline. The individual concentration of the contaminants depends on the quality of coal and the properties of the coking process.
Coke wastewater handling usually consists of a series of physico-chemical treatments reducing the concentration of ammonia, cyanide, solids and other substances, followed by different biological treatments, mainly activated sludge process. The application of two or three consecutive activated sludge systems is particularly favored as readily biodegradable substrates like phenol can be removed in the first step. Phenols, which contribute to the greatest extent to the total COD in coke wastewater, are not only highly toxic and carcinogenic compounds, but also inhibit advantageous biological processes like nitrification. Under optimal circumstances, thiocyanate degradation can also be achieved in the first activated sludge step.
The influent concentrations of NH4+-N, phenols, COD and thiocyanate (SCN-) in the wastewater ranged between 504 and 2340, 110 and 350, 807 and 3275 and 185 and 370 mg/L, respectively. A laboratory-scale activated sludge plant composed of a 20 L volume aerobic reactor followed by a 12 L volume settling tank and operating at 35 ℃ was used to study the biodegradation of coke wastewater. Maximum removal efficiencies of 75%, 98% and 90% were obtained for COD, phenols and thyocianates, respectively, without the addition of bicarbonate. The concentration of ammonia increased in the effluent due to both the formation of NH4+ as a result of SCN- biodegradation and to organic nitrogen oxidation. A maximum nitrification efficiency of 71% was achieved when bicarbonate was added, the removals of COD and phenols being almost similar to those obtained in the absence of nitrification . An anaerobic-anoxic-aerobic (A(1)-A(2)-O) and an anoxic-aerobic (A/O) biofilm system were used to treat coke-plant wastewater. At same or similar levels of HRT, the two systems had almost identical COD and NH3 removals, but a different organic-N removal. Set-up of an acidogenic stage benefited for the removal of organic-N and the A(1)-A(2)-O system was more useful for total nitrogen removal than the A-O system .
Newly studies for treatment of coking wastewaters are listed. Chu et al. investigated coking wastewater treatment by an advanced Fenton oxidation process using iron powder and hydrogen peroxide. The results showed that higher COD and total phenol removal rates were achieved with a decrease in initial pH and an increase in H2O2 dosage. At an initial pH of less than 6.5 and H2O2 concentration of 0.3 M, COD removal reached 44-50% and approximately 95% of total phenol removal was achieved at a reaction time of 1 h. The oxygen uptake rate of the effluent measured at a reaction time of 1 h increased by approximately 65% compared to that of the raw coking wastewater. This indicated that biodegradation of the coking wastewater was significantly improved. Several organic compounds, including bifuran, quinoline, resorcinol and benzofuranol were removed completely as determined by GC-MS analysis. The advanced Fenton oxidation process is an effective pretreatment method for the removal of organic pollutants from coking wastewater. This process increases biodegradation, and may be combined with a classical biological process to achieve effluent of high quality .
Bioaugmented zeolite-biological aerated filters (Z-BAFs) were designed to treat coking wastewater containing high concentrations of pyridine and quinoline and to explore the bacterial community of biofilm on the zeolite surface. The investigation was carried out for 91 days of column operation and the treatment of pyridine, quinoline, total organic carbon (TOC), and ammonium was shown to be highly efficient by bioaugmentation and adsorption. This bioaugmented Z-BAF method was shown to be an alternative technology for the treatment of wastewater containing pyridine and quinoline or other N-heterocyclic aromatic compounds .
6.2. Textile wastewater
Dyes and pigments have been utilized for coloring in the textile industry for many years. Several types of textile dyes are available for use with various types of textile materials. Textile wastewater contains dyes damages the esthetic nature of water and reduces light penetration through the water’s surface, and also the photosynthetic activity of aquatic organisms. It also contains toxic and potential carcinogenic substances. Therefore it must be adequately treated before they can discharge into receiving water bodies. There are several applied treatment methods for textile effluents, involving biological, physical or chemical methods and combinations of these. Among the different technologies that can be applied for the treatment of textile wastewaters, Coagulation-flocculation (CF) and Activated Sludge Process (ASP) are widely used as they are efficient and simple to operate. Generally, these processes can be applied alone to remove suspended colloidal particles or as pre-treatment prior to Ultrafiltration (UF), Nanofiltration (NF) or Reverse Osmosis (RO) respectively for dissolved organic substances removal, decolorization and desalination.
Biological treatment resulted in a high percent reduction in chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), and total phosphorus (TP), and in a moderate decrease in color. The process was found to be independent of the variations in the anoxic time period studied; however, an increase in solids retention time (SRT) improved COD and color removal, although it reduced the nutrient (TKN and TP) removal efficiency. Furthermore, combined treatment (biological treatment and Fenton oxidation) resulted in enhanced color reduction .
The treatability of textile wastewaters in a bench-scale experimental system, comprising an anaerobic biofilter, an anoxic reactor and an aerobic membrane bioreactor (MBR) was evaluated by S. Grilli et al. The MBR effluent was thereafter treated by a nanofiltration (NF) membrane. The proposed system was demonstrated to be effective in the treatment of the textile wastewater. The MBR system achieved a good COD (90-95%) removal; due to the presence of the anaerobic biofilter, also effective color removal was obtained (70%). The addition of the NF membrane allowed the further improvement in COD (50-80%), color (70-90%) and salt removal (60-70% as conductivity). In particular the NF treatment allowed the almost complete removal of the residual color and a reduction of the conductivity such as to achieve water quality suitable for reuse .
Typical contaminants of wool textile effluents are heavy metal complexes with azo-dyes. One of the most representative heavy metals is chromium. In aquatic environments chromium can be present as Cr(III) and/or Cr(VI), mainly depending on pH and redox conditions; the two forms behave quite differently, since Cr(III) is much less soluble and therefore less mobile than Cr(VI). The heavy metal can not be removed by activated sludge effectively. The constructed wetlands (CWs) in full-scale systems and in pilot plants evidenced good performances for several elements, including chromium. Donatella et al investigated the fate of Cr(III) and Cr(VI) in a full-scale subsurface horizontal flow constructed wetland planted. The reed bed operated as post-treatment of the effluent wastewater from an activated sludge plant serving the textile industrial district. Removals of Cr(III) and Cr(VI) was 72% and 26%, respectively. The mean Cr(VI) outlet concentration was 1.6±0.9 g/l and complied with the Italian legal limits for water reuse .
6.3. Food and fermentation wastewater
Food processing and fermentation industries have being experiencing a significant growth in China. Wastewater streams discharged from these industries are generally characterized with high strength organic and nutrient contents, e.g., COD 10000 mg/L, TN 600 mg/L, and tend to bring serious water environment contamination if discharged without proper treatment. The conventional treatment of this kind of high strength wastewater is anaerobic/aerobic activated sludge processes.
Recent years, considerable concern has been focused on the development of the anaerobic membrane bioreactor (AMBR), which is an anaerobic reactor coupled with a membrane filtration unit. The viability of the AMBR treating high-concentration food wastewater depended upon feedwater organic concentration, loading rate, HRT, SRT, hydraulic shearing effect and membrane properties. The HRT kept at 60 h, SRT was designed for 50 days. The effluent COD removal achieved above 90% at loading rate of 2.0 kg/m3/d and above 80% at a loading of 2.0-4.5 kg/m3/d. The membranes all exhibited high efficiency in removal of SS, color, COD and bacteria, reaching 499.9%, 98%, 90%, and 5 logs, respectively .
Wang et al. applied an anoxic/aerobic membrane bioreactor (MBR) to simultaneous removals of nitrogen and carbon from food processing wastewater. The system is proposed to be applied jointly with anaerobic pre-treatment. In order to simulate the quality from anaerobic pre-treatment, raw wastewater taken from a food processing factory was fed to the system after dilution. By continuous runs under appropriate operational conditions, COD, NH4+-N and TN removal was over 94, 91 and 74%, respectively. The anoxic reactor and aerobic MBR contributed 40-63 and 29-46% to COD removal, and 31-43 and 47-64% to NH4+-N removal, respectively. The maximum volumetric COD and TN loadings as high as 3.4 kg COD/m3/day and 1.26 kg N/m3/day were achieved.
Food processing and fermentation wastewaters can be characterized as nontoxic because they contain few hazardous compounds, have high BOD5 and much of the organic matter in them consists of simple sugars and starch. Hence, this high-carbohydrate wastewater is the most useful for industrial production of hydrogen. Food Wastewaters obtained from four different food-processing industries had COD of 9 g/L (apple processing), 21 g/L (potato processing), and 0.6 and 20 g/L (confectioners A and B). Biogas produced from all four food processing wastewaters consistently contained 60% hydrogen, with the balance as carbon dioxide. COD removals as a result of hydrogen gas production were generally in the range of 5-11%. Overall hydrogen gas conversions were 0.7-0.9 L H2/L-wastewater for the apple wastewater, 0.1 L/L for Confectioner-A, 0.4-2.0 L/L for Confectioner B, and 2.1-2.8 L/L for the potato wastewater .
Hydrogen yields were 0.61-0.79 mol/mol for the food processing wastewater (Cereal), ranged from 1 to 2.52 mol/mol for the other samples. A maximum power density of 8177mW/m2 (normalized to the anode surface area) was produced using the two-chambered MFC and the Cereal wastewater (diluted 10 times to 595 mg COD/L), while at the same time the final COD was reduced to lower 30 mg/L (95% removal). Although more studies are needed to improve hydrogen yields, these results suggest that it is possible to link a MFC to biohydrogen to recover energy from food processing wastewaters, providing a new method to offset wastewater treatment plant operating costs .
6.4. Pharmaceutical wastewater
The pharmaceutical manufacturing industry produces a wide range of products to be used as human and animal medications. Treatment of pharmaceutical wastewater is troublesome to reach the desired effluent standards due to the wide variety of the products produced in a drug manufacturing plant, thus, variable wastewater composition and fluctuations in pollutant concentrations. The substances synthesized in a pharmaceutical industry are structurally complex organic chemical that are resistant to biological degradation. Soluble COD removal efficiency is about 62% at 30℃. Therefore, there is a need for advanced oxidation methods. As the process costs may be considered the main obstacle to their commercial application. Cost-cutting approaches have been proposed, such as combining AOP and biological treatment.
Fenton's oxidation is very effective method in the removal of many hazardous organic pollutants from wastewaters. Fenton's oxidation can also be an effective pretreatment step by transforming constituents to by-products that are more readily biodegradable and reducing overall toxicity to microorganisms in the downstream biological treatment processes.
Optimum pH was determined as 3.5 and 7.0 for the first (oxidation 30 min) and second stage (coagulation 30 min) of the Fenton process, respectively. For all chemicals, COD removal efficiency was highest when the molar ratio of H2O2/Fe2+ was 150-250. At H2O2/Fe2+ ratio of 155, 0.3M H2O2 and 0.002M Fe2+, Fenton process provided 45-65% COD removal (influent COD 35000-40000 mg/L) .
Real pharmaceutical wastewater containing 775 mg dissolved organic carbon (3324 mg COD) per liter was treated by a solar photo-Fenton/biotreatment. The photo-Fenton treatment time (190 min) and H2O2 dose (66 mM) necessary for adequate biodegradability of the wastewater. And biological treatment was able to reduce the remaining dissolved organic carbon to less than 35 mg/L. Overall dissolved organic carbon degradation efficiency of the combined photo-Fenton and biological treatment was over 95%, of which 33% correspond to the solar photochemical process and 62% to the biological treatment . Due to the high COD concentration in pharmaceutical wastewaters, anaerobic processes have been made to utilize, such as upflow anaerobic sludge blanket (UASB) reactor, anaerobic filter (AF), anaerobic continuous stirred tank reactor (CSTR) and a hybrid reactor combining UASB and AF. The COD reduction of anaerobic process treating pharmaceutical wastewater containing macrolide antibiotics was 70-75%, at a total HRT of 4 d and OLR of 1.86 kg COD/m3/d .
The two-phase anaerobic digestion (TPAD) system comprised a CSTR and a UASBAF reactor, working as the acidogenic and methanogenic phases, respectively. The wastewater was high in COD, varying daily between 5789 and 58,792mg/L, with a wide range of pH from 4.3 to 7.2. Almost all the COD was removed by the TPAD-MBR system, leaving a COD of around 40mg/L in the MBR effluent, at respective HRTs of 12, 55 and 5 h. The pH of the MBR effluent was found in a narrow range of 6.8-7.6, indicating that the MBR effluent can be directly discharged into natural waters. As demonstrated by an overall COD removal efficiency of more than 99% .
6.5. Sugar refinery wastewater
Sugar refineries generate a highly coloured effluent resulting from the regeneration of anion-exchange resins (used to decolourize sugar liquor). This effluent represents an environmental problem due to its high organic load, intense colouration and presence of phenolic compounds. The colored nature of the effluent is mainly due to (1) the presence of melanoidins, that are brown polymers formed by the Maillard amino-carbonyl reaction and (2) the presence of thermal and alkaline degradation products of sugars (e.g. caramels). Most of the organic matter present in the effluent can be reduced by conventional biological treatments but the colour is hardly removed by these treatments.
The remaining colour can lead to a reduction of sunlight penetration in rivers and streams which in turn decreases both photosynthetic activity and dissolved oxygen concentrations causing harm to aquatic life.
Wastewater obtained from Guangxi Nanning sugar refinery (COD 86.02 g/L) is first diluted by 100 times, then treated by adding amphiphilic flocculants (CMTMC) mg/L at pH 6.6, COD removal to reached to 95%. The wastewater color changed from fuscous brown to buff yellow. After flocculation and purification, the treated water could reach the national first level discharge standards. (GB8978-88, China) .
Sugar refinery wastewater containing high organic load can be used as carbon sources for hydrogen production by microorganisms. As reported pretreated sugar refinery wastewater was used for the production of hydrogen by
7. The cost accounting of different organic wastewater treatment
The cost of organic wastewater treatment includes two parts: the capital expenditure and the operation expenditure. The total cost relates to the characters of the influent, the technique we selected, the characters of the effluent, the time cost during the treatment etc. In this section, the pollutants are divided into degradable and reluctant ones. Some typical wastewater was selected in each group, and the feasible methods to treat it and their cost were discussed.
7.1. The degradable organic pollutants
Wastewater with degradable organic pollutants usually comes from domestic sewage, food processing, breeding industry etc. This wastewater has high BOD, and could break down in the nature condition, given enough time. Most of the techniques could be used to treat the degradable organic pollutants, and biological methods are favorite because of their efficiency and economic properties.
Sewage is one of the most important sources of degradable organic pollutants, which contributes to 37.5% of total COD in China in 2011. Therefore, sewages are treated before discharge in order to reduce the impact of the pollutants to the environment. Several biological methods, including aerobic biodegradation, activated sludge reactor, membrane bioreactor, constructed wetland etc., have been used in the sewages treatment, and their efficiency and cost have been compared. Taking the research of Song as an example, in response to the characteristics of decentralized domestic sewage, several treatment technologies including biogas purification tank, constructed wetland, viewing earthworm ecological, high rate algal pond, membrane bioreactor and integrated treatment equipment were applied to the domestic sewage, and their efficiency and cost were calculated and showed in table 1.
|Operation expenditure|
(104Yuan/m3)
|Quality of the effluent|
(GB18919-2002)
|20-200||0.06-0.08||0.02-0.05||2nd grade|
|30-3100||0.06-0.2||0.05-0.2||1st grade B|
|2-12||0.7-2.0||0.5-1.2||1st grade B|
|-||-||-||1st grade B|
|5-100000||0.19-1.0||0.25-1.05||1st grade B|
|20-||1.0-1.5||0.27-0.8||1st grade A|
According to the technologies, the biogas purification tank, constructed wetland, viewing earthworm ecological and high rate algal pond were characterized by low investment, operating cost, and convenient management. The membrane bioreactor and integrated treatment equipment had the higher operating cost, and the need for professional management, which could be used in the area with higher economic development and stricter effluent qualities.
The industrial waste water from agricultural and sideline food processing industry contain high concentration of organics and suspended substance. Food wastewater is composited of natural organic matters (such as protein, fat, sugar, starch), so they are of low toxicity and high BOD/COD value (up to 0.84). Physical (such as adsorption, air flotation), chemical (flocculation) and biological methods (aerobic biodegradation, activated sludge reactor, sequencing batch reactor, oxidation pond) could be used to remove the pollutants. Most of the physical and chemical techniques are costly and need secondary treatment, therefore, food wastewater was mainly treated by biological methods. The cost varied greatly with the characters of the influent. Longda food industry compared the load and cost of oxidation pond and sequencing batch reactor, results were shown in the table 2 .
|Total cost|
(Yuan/m3)
|Electricity consumption|
(kwh/m3)
|6500||1985300||0.56||0.335|
|4500||1114200||0.455||0.25|
7.2. The reluctant organic pollutants
The reluctant organic pollutants, including benzene series, pharmaceutical intermediates, pesticide etc., mainly come from paper making industry, chemical industry, printing and dyeing wastewater, mechanical manufacturing industry, and agriculture . This kind of wastewater is reluctant to biodegradation either owed to its toxicity or stable structure, therefore, their disposal usually costs higher than degradable ones.
The paper making wastewater reaches 10% of total industrial water. This kind of wastewater contained high concentration and complex structure pollutants, such as lignin, cellulose, hemicellulose, monosaccharide, and could cause serious pollution. The traditional two-stage biochemical treatment has relativity low cost, but the effluent could hardly meet the discharge standard of China owing to its high COD and chroma. The advanced oxidation technique could remove the pollutants from paper making wastewater efficiently, without any secondary pollution. However, the H2O2 used in this method is very expensive, which affects the application and extension of this technology . Flocculation is another efficient method for paper making wastewater treatment, and its COD remove rate could reach 95% at the optimal condition, and the flocculants could be reused after treatment. The cost of this technique is in the middle of the two methods mentioned above (around 1.5-2 Yuan/m3).
The printing and dyeing wastewater contains of much refractory bio-degradable organism with extremely high chrome, therefore, it is hard to be efficiently treated with biological technique . Advanced oxidation could degrade the organisms and reduce the toxicity of this wastewater, but it is too expensive to be used to deal with a great amount of dyeing wastewater. The membrane separation technique could also obtain high pollutants remove rate, but the high cost of the membrane and the energy also hinder the technique from widely application. The flocculation is the most common used technique owing to its moderate price and basically satisfactory results. Partial related with the character of the wastewater, the cost of the flocculation treatment ranges from 3 yuan/m3 to 5 yuan/m3. Some researchers suggested that the combination of the flocculation technique with other techniques, such as Fenton, biological technique could reduce the cost without affecting the effluent quality.
Generally speaking, among all the techniques, biological technique costs the lowest if the pollutants are degradable. The flocculation and adsorption techniques could dispose of the wastewater at a moderate price, but the flocculant and adsorbent need secondary treatment for reuse. Membrane separation and the advanced oxidation could remove pollutants efficiently, but they are costly.
8. Conclusion
The treatment technologies for organic wastewater at present were reviewed. That a variety of technologies such as biological treatment, chemical oxidation technologies, adsorption technology and the others were introduced. At last, the cost accounting of different organic wastewater treatments was discussed.
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Peng Y Hou H Wang S Cui Y Zhiguo Y 2008 Nitrogen and Phosphorus Removal in Pilot-Scale Anaerobic-Anoxic Oxidation Ditch SystemJ Environ Sci 20 4 398 403
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Herney-ramirez J Vicente M. A Madeira L. M 2010 Heterogeneous Photo-Fenton Oxidation with Pillared Clay-based Catalysts for Wastewater Treatment: A reviewAppl. Catal., B. 98 10 26
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Sillanpää METKurniawan TA, Lo W ( 2011 Degradation of Chelating Agents in Aqueous Solution Using Advanced Oxidation Process (AOP)
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Deng Y Englehardt J. D 2006 Treatment of Landfill Leachate by the Fenton ProcessWater Res. 40 20 3683 3694
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Trujillo D Font X Sanchez A 2006 Use of Fenton Reaction for the Treatment of Leachate from Composting of Different WastesJ. Hazard. Mater. B. 138 201 204
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Pirkanniemi K Metsärinne S Sillanpää M 2007Degradation of EDTA and Novel Complexing Agents in Pulp and Paper Mill Process and Wastewaters by Fenton’s Reagent. J. Hazard. Mater. 147 556 561
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Ka-car Y Alpay E Ceylan V. K 2003Pretreatment of Afyon Alcaloide Factory’s Wastewater by Wet Air Oxidation (WAO), Water Res. 37 1170 1176
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Fibbi D Doumett S Lepri L Checchini L Gonnelli C Coppini E Bubba M. D 2012 Distribution and Mass Balance of Hexavalent and Trivalent Chromium in a Subsurface, Horizontal Flow (SF-h) Constructed Wetland Operating as Post-treatment of Textile Wastewater for Water reuseJ. Hazard. Mater. 199-200: 209 EOF 216 EOF
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Haiti (Location Key)
Although Quentin most often refers to it generically as the "West Indies" (192) and Shreve flippantly refers to it as "Porto Rico or Haiti or wherever it was" (239), the place to which Sutpen goes to accomplish the first step in his design is the island of Haiti, as the Chronology and the Genealogy at the end of Absalom! make clear. The "Haiti" in the novel is not the historical Haiti, which successfully won independence from France and abolished slavery in1804, before Sutpen was born; Faulkner's Haiti is still a slave-holding French colony when Sutpen arrives there in 1820, and the slave rebellion depicted in the novel occurs in the late 1820s. Absalom! represents "Haiti" in vague and essentially symbolic terms that evoke both the American dream and Joseph Conrad's descriptions of the Congo in Heart of Darkness. The 14-year-old Sutpen who goes there imagines it as a land of opportunity, "a place called the West Indies to which poor men went in ships and became rich" (195). The one long description of the "little lost island," furnished in Quentin's narrative but based on what his "Grandfather said," locates it in a moral realm rather than in the Caribbean or in history: as "the halfway point between what we call the jungle and what we call civilization," as "a spot of earth which might have been created and set aside by Heaven itself, Grandfather said, as a theatre for violence and injustice and bloodshed and all the satanic lusts of human greed and cruelty" (202). In terms of the story, the most important Haitian setting is the French sugar plantation where Sutpen is an overseer until the slaves revolt, and afterward where he marries his first wife and has his first child, and where he acquires the twenty slaves he brings with him to Yoknapatawpha. In terms of Faulkner's engagement with the issue of slavery, it seems likely that just as he uses the Indians as slave-owners in the story "Red Leaves," so here he uses a foreign country's exploitation of an enslaved population for profit as a way of engaging the history of slavery in the American South at an imaginatively safe distance: 'they' committed this injustice, not 'us.' The planters of Haiti probably bought and sold people and sugar in livres or francs, but the novel's reference to Haiti as the place where "the sheen on the dollars was not from gold but from blood" (201-02) is what Freud called a parapraxis and we call a Freudian slip. | https://faulkner.drupal.shanti.virginia.edu/content/haiti |
The Controlled Substances and Cannabis Branch (CSCB) of the Department of Health of Canada, as part of its mandate to legalize and strictly regulate the production, distribution, sale, possession, and promotion of cannabis and cannabis products, is authorized to disclose non-public information to the United States Food and Drug Administration (FDA) regarding CSCB-quality standards, supporting methodologies, and clinical research safety standards for regulated cannabis products, health products containing cannabis and drugs containing cannabis.
Recognizing the differing legal status of the possession, production and distribution of certain cannabis related products at the federal level in Canada and the United States, FDA understands that information exchanged under this Statement of Authority and Confidentiality Commitment is exclusively for the purposes of supporting cooperative regulatory activities, and where appropriate, cooperative law enforcement activities.
I. UNDERSTANDINGS WITH RESPECT TO SHARED INFORMATION
FDA understands that some of the information it receives from CSCB may include non-public information exempt from public disclosure under the laws and regulations of Canada. Canadian information, including personal information, will only be shared by Canada in accordance with the laws and regulations of Canada. Non-public information may include confidential commercial information; trade secret information; law enforcement information; designated national security information; or internal, pre-decisional information. FDA understands that this non-public information is shared in confidence and that CSCB considers it critical that FDA maintain the confidentiality of the information. Public disclosure of this information by FDA could seriously jeopardize any further scientific and regulatory interactions between CSCB and FDA. CSCB will advise FDA of the non-public status of the information at the time that the information is shared.
Therefore, FDA certifies the following:
- FDA has the authority to protect from public disclosure such non-public information provided to FDA in confidence by CSCB;
- FDA will not publicly disclose or share with other government entities or third parties such CSCB-provided non-public information without the written authorization of the owner or subject of the information, or a written statement from CSCB that the information no longer has non-public status;
- FDA will inform CSCB promptly of any effort made by judicial or legislative mandate to obtain CSCB-provided non-public information from FDA. If such judicial or legislative mandate orders disclosure of CSCB-provided non-public information, FDA will take all appropriate legal measures in an effort to ensure that the information will be disclosed in a manner that protects the information from public disclosure; and
- FDA will promptly inform CSCB of any changes to the United States of America’s laws, or to any relevant policies or procedures, that would affect FDA’s ability to honor the commitments in this Statement of Authority and Confidentiality Commitment.
This Statement of Authority and Confidentiality Commitment does not compromise the regulatory authority of FDA to carry out its responsibilities.
This Statement of Authority and Confidentiality Commitment is not legally binding. FDA understands that CSCB may choose to refuse to share information.
Signed on behalf of FDA:
______________/S/_______________
March 18, 2021
Mark Abdoo
Associate Commissioner
Office of Global Policy and Strategy
U.S. Food & Drug Administration
10903 New Hampshire Avenue, | https://www.fda.gov/international-programs/confidentiality-commitments/fda-cscb-canada-confidentiality-commitment |
1. Field of the Invention
Embodiments of the present invention generally relate to solar cells and methods and apparatuses for forming the same. More particularly, embodiments of the present invention relate to thin film multi-junction solar cells and methods and apparatuses for forming the same.
2. Description of the Related Art
Solar cells convert solar radiation and other light into usable electrical energy. The energy conversion occurs as the result of the photovoltaic effect. Solar cells may be formed from crystalline material or from amorphous or micro-crystalline materials. Generally, there are two major types of solar cells that are produced in large quantities today, which are crystalline silicon solar cells and thin film solar cells. Crystalline silicon solar cells typically use either mono-crystalline substrates (i.e., single-crystal substrates of pure silicon) or a multi-crystalline silicon substrates (i.e., poly-crystalline or polysilicon). Additional film layers are deposited onto the silicon substrates to improve light capture, form the electrical circuits, and protect the devices. Thin-film solar cells use thin layers of materials deposited on suitable substrates to form one or more p-n junctions. Suitable substrates include glass, metal, and polymer substrates. It has been found that the properties of thin-film solar cells degrade over time upon exposure to light, which can cause the device stability to be less than desired. Typical solar cell properties that may degrade are the fill factor (FF), short circuit current, and open circuit voltage (Voc).
Problems with current thin film solar cells include low efficiency and high cost. Therefore, there is a need for improved thin film solar cells and methods and apparatuses for forming the same in a factory environment. There is also a need for a process which will fabricate high stability p-i-n solar cells having high fill factor, high short circuit current, high open circuit voltage and good device stability.
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PORTLAND, OREGON—The International Cost Estimating and Analysis Association (ICEAA) awarded the Space and Naval Warfare Systems Command Cost Estimating and Analysis Division (SPAWAR 1.6) team the Team Achievement of the Year award for 2017.
SPAWAR 1.6 AoA Cost Analysis Team. Led by Min-Jung Gantt from SPAWAR 1.6 and supported by cost analysts (Brian Kadish, Andrew Onufrychuk, and David Todd) from the Kalman & Company, Inc. (Kalman) Business Analytics group, the team was responsible for developing the cost analysis for an Analysis of Alternatives (AoA) for the Navy’s Maintenance, Repair, and Overhaul community. In this capacity, the team developed thorough Life Cycle Cost Estimates and financial evaluation metrics for numerous alternative approaches to meeting the Navy’s maritime maintenance IT toolset requirement. This comprehensive cost analysis was integral to influencing the way forward for maritime maintenance capabilities, a top priority for the Navy’s strategic vision.
The cost analysis challenged technical approaches and assessed their affordability. By identifying the key cost drivers and influencing the discussions in forming viable technical solutions, the SPAWAR 1.6 team was a key contributor of the AoA study. Additionally, the team modified, applied, and advanced key research related to software cost estimating published within the cost estimating and analysis community.
This team differentiated itself as a high performing and effective group through its efficient processes for communicating, implementing, and reviewing cost estimating approaches and methodologies while challenging ideas in a collaborative and constructive way. This collaboration was fostered by intellectual curiosity amongst the group, where they always looked for ways to improve upon the analysis through regular cost model development meetings. During these sessions, each component of the analysis was reviewed, scrutinized, cross checked, and adjudicated by the team with appropriate stakeholder engagement.
Ultimately, this teamwork and collaboration helped influence the direction of the AoA study in not only the cost analysis, but also the other AoA evaluation components like effectiveness analysis, schedule analysis, and trade studies. The team worked closely with the other AoA team members and stakeholders to ensure a consistent analysis approach was used. As a result, the SPAWAR 1.6 team played a unique role in the AoA, influencing the Navy’s strategy development through the team’s comprehensive, detailed, and adaptable analysis.
About ICEAA Awards
ICEAA is a 501(c)(6) international non-profit organization whose mission is to enhance the profession of cost estimating and analysis through the use of parametrics and other data-driven techniques. Each year ICEAA recognizes the outstanding contributions of its members to improve the field within government, industry, and academia. ICEAA established the Team Achievement of the Year Award to recognize a team that demonstrates significant accomplishment and impact on the mission of the organization, or by influencing critical decision-making through the use of cost analysis.
For more information about ICEAA please visit: http://www.iceaaonline.com
About Kalman & Company, Inc. Business Analytics
For more information about our Business Analytics service offerings please contact: | https://www.kalmancoinc.com/news/2017-iceaa-team-achievement-award/ |
Government websites are key platforms for providing public access to information and services. They are also a critical part of government’s internal communication and information sharing infrastructure. Agencies must aim to meet the public expectation that information on government websites is accurate and up-to-date.
Requirements
Agencies must manage their websites and portals in accordance with the Tasmanian Government Website Standards. In particular, the following broad principles, contained within the Tasmanian Government Website Standards, apply to Tasmanian Government websites:
- Public information is made available online except where the head of agency determines not to publish on the web because of:
- high cost relative to the benefit of electronic accessibility
- low usage
- high publication complexity
- low suitability for web delivery.
- Details of public information unavailable on the web must be discoverable on the web. A brief summary must be provided together with details on how to access a copy via email, telephone or mail.
- Agencies must ensure access to, and usability by, the widest possible target community appropriate to the service or information resource.
- Agencies are responsible for the content and must ensure services and information resources provided online are comparable in quality and functionality to those delivered by other means.
When creating websites, agencies should carefully consider whether it is appropriate to publish the information on an existing website or a new website. In particular, information about projects with limited lifespan or expected low public interest may be more appropriately and efficiently published on either the agency’s main website or another existing site.
To ensure publishing standards and communications requirements are met, agencies must:
- clearly identify their websites as being a communication tool of the Tasmanian Government
- link their websites to the Tasmanian Government portal www.tas.gov.au and the Service Tasmania portal www.service.tas.gov.au
- ensure information published on websites is regularly updated, accurate and easy to understand
- ensure information published on websites is accessible to users with disability and/or browse the web using assistive technologies, in accordance with the Tasmanian Government Website Standards
- aim to make non-HTML content (such as PDF or Word) available in a number of alternate formats either on the website or by request
- request new tas.gov.au domain names (where required) in accordance with the Tasmanian Government Domain Naming Guidelines
- provide a mechanism on all websites that allows members of the public to submit comments, questions or feedback directly to the agency
- respect privacy rights and copyright ownership in all online publishing and communication in compliance with the Personal Information Protection Act 2004, the Guidelines on Workplace Email, Web Browsing and Privacy (Australian Privacy Commissioner), and the Copyright Act 1968.
- ensure the permission of subjects is gained of all subjects when publishing photographs or videos on agency websites (see Acknowledgement of Use Image (Adult and Minor) Form)
- ensure information published on websites is recorded and archived in accordance with agency records management policies and with the Archives Act 1983 and the Libraries Act 1984
- procure the services of external website consultants and developers in accordance with the Treasurer’s Instructions, including the Government Information Technology Conditions (GITC), and the specific requirements in section 7.2 Communications procurement. | https://webarchive.libraries.tas.gov.au/20130104043352/http://www.communications.tas.gov.au/policy/methods/8.4_tasmanian_government_websites |
Since 1968, the Fair Housing Act has both protected the rights of individuals seeking a home and simultaneously given landlords and property managers a code of ethics with which to conduct business. This policy has been modified to cite specific groups of people who should not be discriminated against, as well as provide guidance as to what may constitute taking improper adverse action against an applicant for reasons beyond your requirements to gain housing. Now taking a new step in this guidance, HUD is formalizing rules that follow a national standard for determining whether a housing practice violates the Fair Housing law based on an unjustified discriminatory effect.
As this will set a formal process for which all claims of discrimination will be tested for their validity, here, I will break down this new HUD rule into what I call, The 3 Part Burden Shift, for your convenience:
1. The Accusing Proof – This first requirement states that the plaintiff (your applicant) must present their prima facie case (first show of evidence), demonstrating where the policy of the landlord has, or would predictably result in, discrimination. They must prove this on the basis of what classifies one or multiple areas of a protected class.
2. The Defendant’s Rebuttal – Should the plaintiff prove that they have substantial evidence for their case, the burden shifts on to the landlord to provide reasoning behind the necessity for their policy. This policy should display clearly why the practice in question should remain required, and have supporting evidence to reaffirm that it is of substantial, legitimate, and non-discriminatory interests.
3. The Plaintiff’s Last Stand – If the landlord can present their case for retaining the questioned policy as part of their requirements, it becomes the plaintiffs duty to establish liability. The plaintiff must prove that the practice in question could be better served by one that has a less discriminatory effect. Should the plaintiff fail, the case will be dismissed in favor of the landlord.
Here’s one example of HUD’s new ruling in effect: If an applicant is part of the minority who does not have full citizenship in the United States (a green card holder), and your policy defines that you require two forms of valid, state issued ID – the applicant may file a fair housing complaint based on their race or national origin. They would site that they were rejected due to not producing the state issued ID’s (the accusing proof). Your rebuttal would be that is it your policy to verify all residents based on that form of identification and that all applicants receive the same requirement (the defendant’s rebuttal). Once this fact is proven, the applicant may shift the burden once again to file a claim that your policy should be modified to allow other forms of identification be acceptable for those who are legally employed, but not legal citizens (Plaintiff’s Last Stand). Despite that this is (of course) an unlikely situation to occur to these extents, it outlines the general flow that will now be followed by courts nationally. | https://www.cicreports.com/resources/huds-new-ruling-on-fair-housing-standards/ |
Bats are a protected species and as such are a material consideration in planning applications. If your proposed development meets any of the criteria in the trigger list below then your application will not be validated until a bat survey has been submitted.
Bats are widespread throughout the Ribble Valley and are found within a wide variety of buildings due to the excellent habitat that the Forest of Bowland Area of Outstanding Natural Beauty and surrounding countryside provide. The following trigger list is based upon the Bat Conservation Trust guidelines.
For more information on protected species and ecology download our bats information.
Any building located within, or immediately adjacent to woodland and/or water.
Domestic dwellings where a two or single storey extension will result in having to break into or disturb the existing roof.
We will require a bat survey to accompany all schemes to convert barns, outbuildings, and similar traditionally built buildings.
Surveys are not usually required for buildings with single skin roofs and Yorkshire board/profile sheet/open sides unless the area is particularly suitable for bats.
Churches, listed buildings, green space (eg. sports pitches) within 50m of woodland, water, hedgerows, or lines of trees with connectivity to woodland or water.
Any building meeting the criteria laid out in 'Buildings' above.
Water bodies A bat survey is required when work affects rivers, streams, canals, lakes, reedbeds or other aquatic habitat.
Quarries, gravel pits, cliffs and caves Appropriate bat surveys will be required for work affecting any of these areas.
Bats present Any proposal that would affect any building, structure, feature or location where bats are known to be present must be accompanied by an appropriate bat survey.
Why are bat surveys needed?
Bats are a protected species afforded protection under the Wildlife and Countryside Act (1981) (as amended); the Countryside and Rights of Way Act, 2000; the Natural Environment and Rural Communities Act (NERC, 2006); and by the Conservation of Habitats and Species Regulations (2010). As such the Local Planning Authority has a duty to ensure that bats are given due consideration during the planning process. A planning application cannot be granted permission unless due consideration has been afforded to protected species.
Can I do a bat survey myself?
No. We will only accept bat surveys that meet the established standards of the Bat Conservation Trust Bat Surveys - Good Practice Guidelines, and which have been undertaken by a qualified and experienced surveyor. When choosing a consultant you should make sure that they are familiar with the Good Practice Guidelines, ask them about the type of survey they propose to undertake, and the methods they will use. If there are inadequacies with the survey, or not enough surveys have been done then this can hold up your application for many months. A good consultant will be able to show you examples of the work they have done elsewhere.
Download a list of protected species survey consultants.
When can a survey be done?
The timing of bat surveys is very important. Whilst surveys can be undertaken in the winter months to assess the potential of a building being used by bats, if that survey concludes that a building is likely to be used by bats we will not be able to validate your application until you provide further summer surveys. Conversely, in rare cases a summer survey may identify potential hibernacula (bat hibernation roosts), in which case a winter survey will be required. We will only validate an application with an out-of-season survey if that survey concludes that the site is of low potential and that no further surveys are required and we are satisfied that this information is full and accurate.
Winter surveys along will only be acceptable if they find no, or very low potential for bats to be present.
What if an initial building survey concludes further surveys are required?
If a winter, or basic building survey concludes that there is potential for bats to be present we will need further information before we can validate your application. A minimum of three emergence and/or dawn re-entry surveys per building during the active period (May until the end of September) will be required. At least two of the surveys should take place between mid-May and August. If the building has the potential for use by bats throughout the year then this must be reflected in the timing of the surveys.
What should be in a survey?
We expect all surveys to be produced in accordance with the Bat Conservation Trust guidelines. A full bat survey will include: a survey and site assessment; an impact assessment; details of any further surveys that may be required; details of any compensation, mitigation and enhancement measures required; details of post-development safeguarding; a timetable of works; and whether or not a European Protected Species licence will be required. Please note that if bats are present in the area we will expect habitat enhancement measures to be included even if bats are unlikely to be affected by the development.
Low/No Potential - No further survey work/consultation required - carry out work.
Medium Potential - No further survey work/consultation required - carry out work. Proceed with caution and avoid straight felling of tree(s).
High Potential - Further survey work is required ie. aerial inspection of possible bat features using camera/endoscope in the presence of a licensed bat worker. During the active season an evening roost visit by licensed bat workers will be required (an emergence survey). Do not cut through any carcks, splits, holes etc. Consider lowering limbs if possible. Take photographs and contact the Countryside Officer for advice. A natural England licence may be required in order to authorise work.
I had a bat survey done previously can it be re-used?
Bat surveys need to be as up-to-date as possible, therefore it is unlikely that we will accept bat surveys over one year old unless there was no or very low potential for bats. Surveys older than two years will never be acceptable.
Our survey has found bats - now what?
then carrying out the proposed development may lead to a criminal offence being committed.
You may be able to prove that a criminal offence can be avoided by identifying measures to avoid an offence under the provisions of the Conservation of Species and Habitats Regulations 2010. Such proposed measures (mitigation measures) must show a high degree of certainty for success and you will be required to implement such measures as conditions or planning obligations as part of any planning permission that may be granted.
If these three tests cannot be passed, we have no choice other than to refuse the application. Therefore if your survey finds bats we strongly recommend that you submit a supporting statement providing details of any proposed mitigation measures or explaining how the development satisfies these three tests. | https://www.ribblevalley.gov.uk/info/200361/planning_applications/1420/protected_species |
AbstractTopographic map interpretation methods are used to determine erosional landform origins in and adjacent to the Tookany (Tacony) Creek drainage basin, located upstream from and adjacent to Philadelphia, PA. Five wind gaps notched into the Tookany-Wissahickon Creek drainage divide (which is also the Delaware-Schuylkill River drainage divide), a deep through valley crossing the Tookany-Pennypack Creek drainage divide, a Tookany Creek elbow of capture, orientations of Tookany Creek tributary valleys, a narrow valley carved in erosion resistant metamorphic bedrock, and the relationship of a major Tookany Creek direction change with a Pennypack Creek elbow of capture and a Pennypack Creek barbed tributary are used along with other evidence to reconstruct how a deep south oriented Tookany Creek valley eroded headward across massive southwest oriented flood flow. The flood flow origin cannot be determined from Tookany Creek drainage basin evidence, but may have been derived from a melting continental ice sheet, and originally flowed across the Tookany Creek drainage basin region on a low gradient topographic surface equivalent in elevation to or higher than the highest present day Tookany Creek drainage divide elevations with the water flowing in a complex of shallow diverging and converging channels that had formed by scouring of less resistant bedrock units and zones. William Morris Davis, sometimes referred to as the father of North American geomorphology, spent much of his boyhood and several years as a young man living in the Tookany Creek drainage basin and all landforms discussed here were within walking distance of his home and can be identified on a topographic map published while he was developing and promoting his erosion cycle ideas. Davis never published about Tookany Creek drainage basin erosion history, but he developed and promoted uniformitarian and erosion cycle models that failed to recognize the significance of Tookany Creek drainage basin erosional landform features providing evidence of the immense floods that once crossed present day drainage divides and eroded the Tookany Creek drainage basin.
- Full Text: PDF
- DOI:10.5539/jgg.v8n4p30
This work is licensed under a Creative Commons Attribution 4.0 License. | https://www.ccsenet.org/journal/index.php/jgg/article/view/64856 |
Features : Made from a sustainably farmed rattan in Myanmar.
Add a little bit of 'resort style' into your life with this beautifully finished breakfast basket. This woven basket is perfect for presenting your next breakfast bakery treats. such as croissants, rolls and crumpets. You can also leave it in your pantry to store away with your bakery products on it or any other dried goods. Is very versatile and can easily be used anywhere throughout the home. | https://hamptonshouse.com.au/products/breakfast-basket |
Enthalpy in Intensive Units – Specific Enthalpy
The enthalpy can be made into an intensive, or specific, variable by dividing by the mass. Engineers use the specific enthalpy in thermodynamic analysis more than the enthalpy itself. The specific enthalpy (h) of a substance is its enthalpy per unit mass. It equals to the total enthalpy (H) divided by the total mass (m).
h = H/m
where:
h = specific enthalpy (J/kg)
H = enthalpy (J)
m = mass (kg)
Note that the enthalpy is the thermodynamic quantity equivalent to the total heat content of a system. The specific enthalpy is equal to the specific internal energy of the system plus the product of pressure and specific volume.
h = u + pv
In general, enthalpy is a property of a substance, like pressure, temperature, and volume, but it cannot be measured directly. Normally, the enthalpy of a substance is given with respect to some reference value. For example, the specific enthalpy of water or steam is given using the reference that the specific enthalpy of water is zero at 0.01°C and normal atmospheric pressure, where hL = 0.00 kJ/kg. The fact that the absolute value of specific enthalpy is unknown is not a problem, however, because it is the change in specific enthalpy (∆h) and not the absolute value that is important in practical problems.
Specific Enthalpy of Wet Steam
The specific enthalpy of saturated liquid water (x=0) and dry steam (x=1) can be picked from steam tables. In case of wet steam, the actual enthalpy can be calculated with the vapor quality, x, and the specific enthalpies of saturated liquid water and dry steam:
hwet = hs x + (1 – x ) hl
where
hwet = enthalpy of wet steam (J/kg)
hs = enthalpy of “dry” steam (J/kg)
hl = enthalpy of saturated liquid water (J/kg)
As can be seen, wet steam will always have lower enthalpy than dry steam.
Example:
A high-pressure stage of steam turbine operates at steady state with inlet conditions of 6 MPa, t = 275.6°C, x = 1 (point C). Steam leaves this stage of turbine at a pressure of 1.15 MPa, 186°C and x = 0.87 (point D). Calculate the enthalpy difference between these two states.
The enthalpy for the state C can be picked directly from steam tables, whereas the enthalpy for the state D must be calculated using vapor quality: | https://www.nuclear-power.net/nuclear-engineering/thermodynamics/what-is-energy-physics/what-is-enthalpy/specific-enthalpy/ |
Table of contents
- What Is Tooth Sensitivity?
- What May Cause It?
- What Tooth Sensitivity Treatments Are There?
When it comes to dental care, tooth sensitivity is one of the most common issues people come across. Whether you’re experiencing on and off pain or you’re struggling with day-to-day tasks, you need to be sure you’re doing all you can when it comes to pain relief.
With that in mind, we want to ensure you have everything you need when it comes to helping treat your pain at home.
What Is Tooth Sensitivity?
To start, let’s take a look at what tooth sensitivity is, as often it can be confused with toothache. To put it simply, if you have sensitive teeth, certain activities such as brushing and eating can cause temporary sharp pains in your teeth. This pain is something that happens regularly, not just once or twice.
According to the Academy of General Dentistry, when it comes to oral health there are around 40 million people in the United States that currently experience some form of tooth sensitivity.
The symptoms of tooth sensitivity include:
If you’re unsure whether or not you’re experiencing tooth sensitivity, looking at the symptoms can certainly help. Those that do have sensitive teeth may find that they experience pain or discomfort as a response to certain triggers. These triggers are different for different people, but the pain is usually at the roots of the affected teeth.
The most common triggers for teeth sensitivity are:
- hot foods and hot drinks
- cold foods and cold drinks
- cold air
- sweet foods and drinks
- acidic foods and drinks
- cold water
- brushing or flossing your teeth
- mouth rinses that are alcohol-based
- Over time you may find that your symptoms may come and go for no obvious reason and depending on the trigger they may range from mild to intense pain.
What May Cause It?
Another common question when it comes to tooth sensitivity is what causes your teeth to be sensitive, as not everyone experiences the pain. Typically, sensitive teeth are a result of either worn tooth enamel or exposed tooth roots.
Although they’re the most common causes, you may also find that there are few other reasons your teeth may be feeling a little sensitive. This includes cavities, a cracked tooth, worn fillings or gum disease.
What Tooth Sensitivity Treatments Are There?
Although finding the source of your sensitivity is crucial when it comes to recommending treatment, here are just a few of the home-remedy treatments that can help you. It’s important to note that you may find that you need to try a couple before you one that works for you.
Salt Water Rinse
Salt is known to be an effective antiseptic and if used correctly, can help to reduce inflammation.
If you’re looking to use salt water to alleviate your pain, it’s best to start off by gargling with a saltwater rinse twice a day. To do this, all you need to do is add ½ to ¾ tsp salt to a glass of lukewarm water and mix well. Swish the solution in your mouth for at least 30-seconds, spitting it out once you’re done.
Desensitizing Toothpaste
If you experience pain while brushing, desensitizing toothpaste is a great place to start as it can help reduce your sensitivity throughout the day too.
For those that don’t know how it works, desensitizing toothpaste contains compounds that help to shield nerve endings from any irritants. After just a few uses, you will notice that your sensitivity has reduced, so dentists will often recommend this to those that suffer daily.
Honey With Hot Water
Although it may not be it’s most common use, honey is also known to be an antibacterial agent that is used in wound management. If you’re experiencing sensitivity, honey can be used to help reduce the inflammation and speed up the healing process. All you need to do is rinse your mouth out with warm water and a spoonful of honey!
Hydrogen Peroxide
Although it may not sound safe, hydrogen peroxide is can be used as a mild antiseptic and disinfectant. Commonly used to help sterilize cuts and burns, peroxide is also used as a mouth rinse that heals your gums and prevents inflammation. To rinse, add two caps of 3% hydrogen peroxide to two caps of warm water and swish for 30 seconds. Once you have used the peroxide rinse, rinse your mouth out again to remove any residue.
Green Tea
Not only is green tea delicious, but it’s also another product that is known for it’s incredibly benefits to health. One of the lesser-known uses for green tea is in relation to dental care, especially for those with sensitive teeth. If you do want to use green tea, try using unsweetened green tea as a mouthwash both morning and night.
Turmeric
As well as being used in various different recipes, turmeric is a known anti-inflammatory treatment, great for those that are suffering from a pulsing sensation as a result of their sensitive teeth.
When it comes to oral health and Tumeric, you can alleviate the pain from your sensitive teeth by massaging ground Tumeric onto them. Alternatively, you can create a paste using 1 tsp turmeric, ½ tsp salt, and ½ tsp mustard oil. Applying this paste twice a day has been proven to help with pain relief.
Vanilla Extract
Vanilla extract contains antiseptic, giving it various different pain-relief properties. Commonly used to treat babies’ pain and discomfort, parents often use this when their children are teething as it tastes better than many alternatives. Using a cotton ball, apply the vanilla extract to your gums as often as is needed.
Capsaicin
The compound found in chilli peppers, otherwise known as capsaicin, has properties that are used to reduce inflammation and pain. If you have sensitive teeth, capsaicin can be used as either a gel or mouth rinse. Although it might burn, to begin with, it will eventually reduce pain symptoms of tooth sensitivity. | https://alignerco.com/blogs/blog/tooth-sensitivity-treatments |
eso0031-en-au — Photo Release
Stars and Nebulae in the Southern Crown
A Colourful WFI Portrait of a Star-Forming Region
6 October 2000
The R Coronae Australis complex of young stars and interstellar gas clouds is one of the nearest star-forming regions, at a distance of approx. 500 light-years from the Sun. It is seen in the southern constellation of that name (The "Southern Crown"). Images of this sky area were recently obtained with the Wide Field Imager (WFI), a 67-million pixel digital camera that is installed at the 2.2-metre MPG/ESO Telescope at ESO's La Silla Observatory.
Some of these exposures have been combined into a magnificent colour image, here reproduced as ESO Press Photo eso0031a. The field shown measures about 4.7 x 4.7 light-years. It displays the central part of the complex, its brightest stars, and the nebulosity that they illuminate. The interstellar clouds that are associated with the complex are visible all across this field and also beyond its borders (on other exposures), due to the obscuring effect of the dust particles that "dim" the light of stars behind these clouds. This effect is particularly noticeable in the lower left corner where very few stars are seen.
R Coronae Australis, the bright star from which the entire complex is named, is located at the center of the field and illuminates the reddish nebula around it. The bright star in the lower part, illuminating a somewhat bluer nebula, is known as TY Coronae Australis .
The brightness of these two stars and several others in the same field is variable. They belong to the so-called "T Tauri" class, a type that is quite common in star-forming regions. T Tauri stars are in the early stages of stellar evolution and display various observable characteristics of this phase, e.g. emission at visible and infrared wavelengths due to the accretion of matter left over from their formation, as well as X-ray emission.
The nebulosity seen in this picture is mostly due to reflection of the stellar light by small dust particles. The stars in the R Coronae Australis complex do not emit sufficient ultraviolet light to ionize a substantial fraction of the surrounding hydrogen, and thereby cause this gas to glow.
However, some smaller features are also visible (one is seen in the upper left corner of ESO Press Photo eso0031b) which emit light by a different mechanism. These are so-called Herbig-Haro objects, i.e., dense clumps of gas ejected from the immediate vicinity of newly formed stars with velocities of about 200 km/sec. When such clumps ram into the gas, the atoms are heated (excited) and start to shine. See also ESO Press Photo eso9948 of the object HH-34 in Orion.
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The Sheldon Art Galleries will unveil several fantastic exhibits tonight from 5:00 p.m. through 7:00 p.m. Two of these exhibits will be of great interest to readers of this blog.
Designing the City: An American Vision
October 1, 2010 – January 15, 2011
Drawn from the Bank of America collection, this exhibition offers a unique opportunity to see some of the great architectural works built across America and the cities for which they are an integral part. Photographers included are Berenice Abbott: Harold Allen; Bill Hedrich, Ken Hedrich and Hube Henry of the Hedrich-Blessing Studio; Richard Nickel; and John Szarkowski. It is through photographs that most of us have come to know major works of architecture. Our experience of great architecture is often not at the building’s actual site, but rather through a two-dimensional photographic rendering of it. In fact, for many buildings, photographs are all that remain. The term, “architectural photography” is widely used and generally understood to describe pictures through which the photographer documents and depicts a building in factual terms. However the artists featured in this exhibition have taken architectural photography beyond its informative purpose and have shown us the importance of architecture in the definition of the urban American landscape.
Group f.64 & the Modernist Vision: Photographs by Ansel Adams, Edward Weston, Imogen Cunningham, Willard Van Dyke, and Brett Weston
October 1, 2010 – January 15, 2011
Seminal works by renowned photographers Ansel Adams, Edward Weston, Imogen Cunningham, Willard Van Dyke, and Brett Weston, including several spectacular large-scale prints by Ansel Adams — among them Moonrise, Hernandez, New Mexico, 1941 — as well as Edward Weston’s iconic Pepper, 1930, and examples of Imogen Cunningham’s beautiful and sculptural flower closeups are shown in this exhibition alongside rarely seen works by the artists, all drawn from the Bank of America collection.
Founded in 1934 by Willard Van Dyke and Ansel Adams, the informal Group f.64 were devoted to exhibiting and promoting a new direction in photography. The group was established as a response to Pictorialism, a popular movement on the West Coast, which favored painterly, hand-manipulated, soft-focus prints, often made on textured papers. Feeling that photography’s greatest strength was its ability to create images with precise sharpness, Group f.64 adhered to a philosophy that photography is only valid when it is “straight,” or unaltered. The term f.64 refers to the smallest aperture setting on a large format camera, which allows for the greatest depth of field and sharpest image. | http://preservationresearch.com/events/exhibits-starting-tonight-at-the-sheldon/ |
One need only get an American and Brit in the same room to understand that there’s a bit of grammatical strife between the two. But these discrepancies aren’t uncommon. There are a myriad of differences, disparities and contradictions in naming conventions, categorisation and units of measure across the globe.
Of course, a lot of this has been eliminated by the International Standards Organisation, who aim to make life easier for us cross-border operators. But the problem usually arises at application – for not all countries, companies or individuals readily adopt, or are even aware of, international standardisation.
We’ve listed a few interesting international conundrums below
Billion or billion
We won’t resort to numeric name calling, here, but we really wish the Yanks and Brits could reach some consensus on the naming of numbers. Indeed, although the French are to thank (and to blame) for the different conventions, the USA has adopted the more nouveau version of integer naming whilst most of England remains rather oblivious of this change.
For when you’re in America (and South Africa for that matter), you’ll make use of the short scale (échelle courte) – a system which stipulates that every new term greater than a million will be one thousand times larger than the previous term. A billion in America therefore means a thousand million (109), whereas a trillion means a thousand billions (1012).
Return to the land of tea and scones, and you’ll probably have to revert to the long scale (échelle longue), a system which stipulates that every new term greater than a million is one million times larger than the previous one. So the British billion means a million millions (1012), while a trillion means a million billions (1018).
Although the British government officially adopted the short scale in the 70s and it has been used for official purposes since, it is still widely used in the UK, continental Europe and most French, Spanish and Portuguese-speaking countries.
Going to East or South Asia? Well, then you’ll have to use a completely different scale altogether. Brace yourself for some international mathematical tom-foolery.
Blue vs Blue
Linguistic relativity postulates that people will not use or apply concepts if they have no words for these concepts. George Orwell, for instance, used ‘Newspeak’ in 1984 – a language which prohibited innovative thinking by removing words which describe alternative concepts. He theorised that people who have no words to describe a revolt would not be able to start a revolution. Of course, linguistic relativity is not the only theory for this, but it is a widely accepted one.
Although this idea may sound farfetched, it has been widely studied and confirmed – especially with regards to colour theory and identification. Although colour palettes exist universally, people who don’t have words to identify different colours seem to find it difficult to see a difference between these colours. The Dani people of Indonesia do not have different words for green and blue, and when they were pitted against other language speakers they scored significantly lower in colour identification. It would seem they could not ‘see’ the difference, because they had no word to describe it. In this same way the inuit people don’t just see white, but various colours in a spectrum when referring to white, whereas most English speakers will not discern small nuances in white.
Ton or tonne
If you’re a South African who’s been foolish enough (like the most of us) to use ‘ton’ when referring to 1 000 kg, then we have some news for you – you’ve been doing it wrong.
The tonne (or metric ton) is the correct word to use when referring to a 1 000 kg, while a ton (used in America and Canada) equals 907,1847 kg. The confusing part is that these homophones are also closely related in meaning. Usually, homophones have completely different meanings, yet in the case of tonne and ton, the similarities far outweigh the differences… unless you are an engineer, physicist or builder or course – because 92,8153 kg makes a huge difference in the real world.
Of course, the confusion doesn’t stop there. Ton is used both in America and internationally as a noun for an ‘indefinable heavy weight’. So although it is a unit of measure – and therefore by definition needs to be scientifically accurate – it is also used to describe a weight of vaguely heavy proportions. This means the word is essentially a contronym… just like our word below.
Literally vs literally
Grammar nazis step aside – for you’re bound to get this one wrong.
The exciting thing about language is that it’s fluid. It adapts, changes, discards and adopts whatever is necessary for its own survival. In fact, linguists are clear that one of the greatest indicators for language survival and growth is its ability to adapt. Of course, this is a bitter pill to swallow for language purists, who believe that their way is the only way, and that (for some unfathomable reason) everything else in the world may change, save for language. It is important to remember that language is a naturally occurring process which evolves on its own despite, and not as a result of, language rules.
So here’s the kicker – you know when your friend literally had that heart attack and you literally kicked him for using literally instead of figuratively? Well, looks like you need a kick. In 2013 the definition of the word ‘literally’ changed to include it’s antonym… ‘figuratively’. So literally quite literally means figuratively.
The reason for this change is that lexicographers don’t prescribe language usage. Like most linguists, they rather study language and observe how it is used by its speakers. Essentially, word etymology and usage is dependent on the users (of course), so if words or terminology are widely used or misused, the definitions will essentially be adapted to suit the speaker.
So could the world do with standardisation? It certainly will overcome confusion, and yet it really does make life interesting.
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Subscribe to the FinGlobal newsletter to receive all the latest news and information regarding our services and South African Expats. | https://www.finglobal.com/2015/12/15/worldwide-disparities-why-you-dont-see-what-i-see/ |
Case study ( 4807 views as of February 20, 2020 )
Karen is a busy mom of two who works from home as an editor. She has been following a strict eating and exercise plan that she copied from a popular TV health show but has not been successful in her weight loss efforts. Her goal has been to lose 15 lbs and 3 inches from her waist.
Her current measurements include a weight of 163 lbs, height of 168 cm, and a waist circumference of 38 inches.
Karen ensures that she eats within 30 minutes of waking up and then eats a small meal or snack of 200-300 kcal every 3 hours. She eats yogurt and a granola bar for breakfast, has fruit or air-popped popcorn for snacks, various soups for lunch, and a small portion of protein with vegetables for dinner. Karen keeps her total caloric intake to 1500 kcal per day.
Karen goes to the gym 3 days a week and focuses on cardio activities such as the elliptical trainer and recumbent bikes. With her sedentary job, she is always looking for ways to increase her activity through the day. She ensures she gets up every hour and tries to do 10 minutes of stair climbing, walking or dancing at each break. She also wears a step counter to compare her daily activity.
Karen recently saw her family physician who suggested that although she is doing everything right, she may be battling a slow metabolism. After testing her thyroid levels and finding normal results, the physician suggests speaking with a dietitian to re-assess her diet and provide tips to help stimulate her metabolism. In addition to dietary changes, the physician also suggests seeing a personal trainer to provide some muscle building activities into her workout plan which will further boost Karen's metabolism.Author: Ms. Sarah Ware
Conversation based on: Weight Loss and Slow Metabolism " Karen a busy mom of two "
Weight Loss and Slow Metabolism " Karen a busy mom of two " | https://healthchoicesfirst.com/health-talks/weight-loss-and-slow-metabolism |
The Wetlands Institute is pleased to announce our 7th Annual Spring Shorebird and Horseshoe Crab Festival, a weekend packed with conservation-based, hands-on, interactive activities for all ages.
Located on the Cape May Peninsula between the Delaware Bay and Atlantic beaches, The Wetlands Institute is situated in an area considered to host one of the “wonders of the world.” With an act of timing only Mother Nature can provide, Horseshoe Crabs climb onto the beaches of Delaware Bay to lay their eggs, while thousands of shorebirds time a stop on their northbound spring migration route to feed on these energy-packed eggs. Our shores host the largest concentration of spawning horseshoe crabs in their range, and the shorebird migration is one of the last great migrations on Earth. What an amazing front row view of these spectacular wildlife events we have, and it can be seen right here in Cape May.
Come join The Wetlands Institute for a festival that celebrates this amazing spectacle of nature – the shorebird migration and horseshoe crab spawning season. Guests of all ages can enjoy a variety of conservation-based activities including guided shorebird viewings; horseshoe crab workshops; horseshoe crab spawning survey demonstrations and reTURN the Favor walks; aquarium teaching tank and aquaculture tours; naturalist-led Salt Marsh Trail walks; and other hands-on education and conservation-based activities.
Proceeds from the event will help support The Wetlands Institute’s conservation and education programs focused on shorebird and horseshoe crab conservation. | http://wetlandsinstitute.org/events/spring-shorebird-and-horseshoe-crab-festival/ |
Summary of Hobbes Leviathan – The construction of a commonwealth through social contract, according to Leviathan, is the greatest way to attain civic peace and social harmony.
In Hobbes’ ideal commonwealth, sovereign power is in charge of maintaining the commonwealth’s security and is given total authority to secure the common defense.
Hobbes depicts this commonwealth as an “artificial person” and a political body that resembles the human body in his introduction.
Hobbes assisted in the creation of the frontispiece for the first edition of Leviathan, which depicts the commonwealth as a massive human body made up of the bodies of its inhabitants, with the sovereign as its head.
Summary of Hobbes Leviathan
Hobbes Leviathan
Leviathan or The Matter, Forme, and Power of a Commonwealth Ecclesiasticall and Civil is the full title of the book. Isn’t that something to be proud of? However, it may be a mouthful. As a result, it’s more generally referred to as just “Leviathan” to save time.
In essence, Leviathan is one of the earliest works to address the issues of societal contract and power structures. It’s vital to remember that the English Civil War served as the setting for the Leviathan novel. As a result, Hobbes’ query about the condition of nature is a natural reflection of his period.
Thomas Hobbes
The author, Thomas Hobbes, an English philosopher, argues for the advantages of a sovereign government. He thinks it is a vital type of government over human civilization, despite its shortcomings. To overcome the anarchy and violence of human nature, a firm governing hand is required.
Given how long ago it was written and the necessity to continuously reference the entire historical backdrop, it may be a challenging read. But, in the end, it provides incredibly useful insight into the minds of the time’s political thinkers.
Order Now and get professional academic writing on the following topic at a reasonable price. Click here to read more free samples. | http://www.customessaydorm.com/summary-of-hobbes-leviathan/12418/ |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor apparatus which comprises a semiconductor substrate and plural elements formed on the substrate. More particularly, it relates to a method of manufacturing a semiconductor apparatus comprising elements arranged on a substrate at as high a density as in an LSI, in which method regions separating the elements are formed sufficiently narrow, thereby enhancing the integration density of the apparatus.
2. Description of the Related Art
To manufacture a semiconductor apparatus having a high integration density, like an LSI, plural elements are formed on a semiconductor substrate, and regions are also formed on the substrate to separate the elements from one another. In a known method, such regions (hereinafter called "separating regions") are formed by oxidizing the selected portions of an insulation layer. This selective oxidation is called a LOCOS process.
In the LOCOS process, a pattern mask of silicon nitride is formed on those portions of a semiconductor substrate (a silicon wafer) where elements will be formed. (These portions of the substrate will be referred to as "element regions.") When the pattern mask has been formed, the substrate is heated and oxidized. As a result, an oxide film is formed on those portions of the substrate which are not covered by the pattern mask and are thus exposed.
The LOCOS process is easy to perform, and serves to manufacture a semiconductor apparatus with a high degree of accuracy. In view of this, the LOCOS process is advantageous. However, when this process is peformed, thus forming narrower separating regions, thereby to enhance the integration density of the semiconductor apparatus, the following problem will arise.
When the substrate is heated and oxidized, with a pattern mask formed on the element regions of the substrate, even those unexposed portions of the substrate which extend along the edges of the mask patterns are oxidized, too. These portions are called "bird's beaks," and are usually as wide as about 0.6 &mgr;m.
What is used as an element region is that portion of the nitride film- covered area which excludes the bird's beaks. This means that each separating region includes the bird's beaks. It is therefore difficult to make the separating region sufficiently narrow. The bird's beaks must be eliminated in order to enhance the integration density of the semiconductor apparatus.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method of manufacturing a semiconductor apparatus, which can form sufficiently narrow seprating regions on a semiconductor substrate, separating a plurality of elements formed on the substrate, thereby to enhance the integration density of the semiconductor apparatus.
Another object of the invention is to provide a method of manufacturing a semiconductor apparatus, which can form an oxide film on a semiconductor substrate by using a pattern mask, and can form bird's beaks under the edge portions of each mask pattern such that the bird's beaks are used as parts of element regions, thus reducing the width of separating regions so that the apparatus has a high integration density.
A further object of the invention is to provide a method of manufacturing a semiconductor apparatus, which can reduce the channel width of an semiconductor element. When a MOSFET is formed in each element region separated from the other element regions by the separating regions, the MOSFET has a channel width which is small enough to raise the threshold voltage of the MOSFET.
According to a method of manufacturing a semiconductor apparatus whereby a plurality of elements can be formed on a substrate, patterns of silicon nitride film are formed at those areas on the surface of the semiconductor substrate where elements are formed, and boron ions are injected into the surface of the substrate, using the pattern, to form a channel stop region and a heat oxidized film. Ions of Si, N or the like are then injected into the heat oxidized film with such an acceleration energy that the ions do not pass through the silicon nitride film to thereby to change the quality of the heat oxidized film, thereby forming a reformed layer. The silicon nitride film is then removed by an etching liquid of phospheric acid including even the bird's beak which is along and under the peripheral rim of each of pattern mask of the silicon nitride film.
The heat oxidized film is formed even under the silicon nitride film in the course of forming the heat oxidized film to thereby form the bird's beak along and under the peripheral rim of each of pattern mask of the silicon nitride film. The reformed layer is formed on the heat oxidized film where no silicon nitride film is present by ion injection. When the heat oxidized film (SiO.sub.2) is etched after the silicon nitride film is removed, therefore, the bird's beak portions where no reformed layer is present are selectively etched to determine those portions where silicon nitride film is present as element areas, so that the elements separating region can be easily made narrow. Further, the bird's beak portions act to suck boron ions. Therefore, the concentration of boron ions which are injected to form a channel stopper becomes low at the element areas formed and the narrow channel effect of MOS transistors, for example, formed at the element areas can be thus effectively improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 6 are sectional views showing a method of manufacturing a semiconductor apparatus according to the present invention, particularly the process of forming an element separating region; and
FIG. 7 is a graph showing a relation between the thickness of silicon nitride film and ion injection energy at the time when ions injection is conducted to form a reformed layer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be described referring to an example of forming polysilicon gates C - MOS. Needless to say, the present invention can be applied to bipolar elements and the like.
In FIG. 1, semiconductor substrate 11 is a silicon wafer, for example. Pad oxidized film 12 which is a thin silicon oxidized film is formed on the surface of semiconductor substrate 11 according to the heat oxidizing manner. Silicon nitride film is formed all over the pad oxidized film 12 according to the CVD manner. This silicon nitride film is etched to a certain pattern by photo-etching or the like to form silicon nitride film mask 13. Width W of a silicon nitride film mask 13 corresponds to an element area while that portion on semiconductor substrate 11 where no silicon nitride film mask is present and where pad oxidized film 12 is exposed corresponds to an element separating region in this case.
When silicon nitride film mask 13 are formed in this manner, boron ions are injected into that surface region of semiconductor substrate 11 which corresponds to the element separating region to form channel stopper region 14 of P.sup.+ type under the element separating region, as shown in FIG. 2.
That surface portion of semiconductor substrate 11 which includes no silicon nitride film mask 13 is heat-oxidized to form thick heat oxidized film 15 (LOCOS oxidization), as shown in FIG. 3.
An oxidized film which is called bird's beak 151 is formed along and under the peripheral rim of each of silicon nitride film masks 13 by this heat oxidizing treatment, entering only by width &Dgr;W under silicon nitride film mask 13 and gradually tapering as it comes to its front end when seen in section. An area denoted by W1 and including no bird's beak 151 becomes smaller as compared with width W of silicon nitride film mask 13.
When heat oxidized film 15 is formed like this, ions of Si, N, C or the like are injected into all over semiconductor substrate 11, as shown in FIG. 4. The energy for accelerating ion in the course of this ions injection is selected to be such that the ions are not injected into the silicon nitride film, thereby to change the quality of the heat oxidized film.
Considering the thickness of silicon nitride film mask 13 and the acceleration energy with which ions of Si cannot pass through mask 13 in a case where ions of Si, for example, are injected, the acceleration energy available in relation to the thickness of the silicon nitride film mask is shown in FIG. 7. The graph in FIG. 7 shows results calculated from the theory of LSS (Lindhard, Shariff, Schiott).
The surface of heat oxidized film 15 except bird's beak 151 is reformed by this ion injection process to thereby form surface reformed layer 16.
When silicon ions, for example, are injected, silicon-rich layer (SiOx) is formed as reformed layer 16 and when N ions, for example, are injected, oxynitride is formed as reformed layer 16. The etching speed at which these reformed layers 16 are etched by the etching liquid of hydrofluoric acid or the like is by far lower than in the case of common oxidized silicon.
When surface reformed layer 16 is formed in this manner, silicon nitride film mask 13 is removed, as shown in FIG. 5, after some heat treatment.
The removal of silicon nitride film mask 13 is carried out according to a common process such as wet etching by phosphoric acid, for example, or dry etching by fluorine plasma, for example. Only silicon nitride film mask 13 is selectively removed by this etching treatment.
When heat oxidized film (SiO.sub.2) 15 is etched by hydrofluoric acid solution after silicon nitride film mask 13 is removed, bird's beak portions 151 where no surface reformed layer 16 is present are mainly etched to expose the surface of semiconductor substrate 11, as shown in FIG. 6.
Bird's beak portions 151 are selectively removed and width W2 of an area partitioned by heat oxidized film 15 is made sufficiently larger than width W1 shown in FIG. 3. This area having width W2 is an element area and width W2 of this area is substantially equal to width W of silicon nitride film mask 13 shown in FIG. 1.
When channel stopper region 14 of P.sup.+ type which is formed by boron ions injection is heat-treated according to LOCOS oxidization to form heat oxidized film 15, it is elongated in the traverse direction, entering under the element areas, as shown in FIG. 3. When the region into which boron ions are injected is formed entering under the device areas like this, the narrow-channel effect acts on MOSFET, for example, formed at these device areas.
When bird's beak portions 151 are temporarily formed and then removed according to the present invention, however, the concentration of boron at the element areas partitioned by heat oxidized film 15 can be made sufficiently low because bird's beak portions 151 serve to absorb boron ions. Therefore, MOSFET, for example, formed at the element areas can be left free from the narrow-channel element, thereby effectively restraining threshold voltage of MOS transistors from rising. | |
At pyramidal neurons, action potentials generated in the axon hillock back-propagate into the dendrites activating different types of voltage-gated Ca2+ channels (VGCCs). The consequent Ca2+ signal represents a precise code for the dendritic sites where the cell receives synaptic inputs and plays itself a role in the propagation of electrical signals within the dendrites. Using a recently developed optical technique (Jaafari et al. 2014) we investigated in detail the activation of dendritic VGCCs during physiological action potentials. All types of high-voltage activated (HVA) VGCCs (L-type, N-type and P/Q type) contribute to the kinetics of action potentials, in particular by activating K+ channels. The longer lasting action potential prolongs the duration of activation of low-voltage activated Ca2+ channels (T-type). The result is a compensation of the loss of the Ca2+ signal component mediated by LVA VGCCs with the larger component mediated by LVA VGCCs. Thus, functional coupling of VGCCs underlies the high-fidelity of fast dendritic Ca2+ signals during individual action potentials which occur in the majority of the dendritic field.
Jaafari N, De Waard M, Canepari M (2014) Imaging Fast Calcium Currents beyond the Limitations of Electrode Techniques. Biophys J 107 : 1280-1288. | http://www.int.univ-amu.fr/Marco-Canepari |
What is Ethnobotany?
Ethnobotany is the study of how people of a particular culture and region make use of indigenous (native) plants. Since their earliest origins, humans have depended on plants for their primary needs and existence. Plants provide food, medicine, shelter, dyes, fibers, oils, resins, gums, soaps, waxes, latex, tannins, and even contribute to the air we breathe. Many native peoples also used plants in ceremonial or spiritual rituals. Examining human life on earth requires understanding the role of plants in historical and current day cultures.
Plants and People
Throughout time, countless peoples have tested and recorded the usefulness of plants. Those plants with beneficial uses were kept and utilized. Our cultures evolved by passing from generation to generation ever more sophisticated knowledge of plants and their usefulness. Even today, we depend upon plants and their important pollinators for our existence and survival.
Related Sites
Great Lakes Anishinaabe Ethnobotany
The Great Lakes Anishinaabe Ethnobotany site website is a collaboration between the Cedar Tree Institute and the Northern Michigan University Center for Native American Studies both located in Marquette, Michigan, and the USDA Forest Service. The website features video interviews, a collection of personal stories and cultural teachings related to various plants and trees of the upper Great Lakes region.
Medicinal Plants of the Southwest (MPSW)
The Medicinal Plants of the Southwest (MPSW) program, is funded by the National Institute of Health as part of the Research Initiative for Scientific Enhancement (RISE) Program at NMSU.
Native American Ethnobotany
A database of foods, drugs, dyes, and fibers of Native American peoples, derived from plants, hosted on the University of Michigan, Dearborn website.
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HEALING: A GIFT OR A TREND?
My name is Makhosi Sphoko-Siphamandla Gwala, and I am named after a life changing Training on Traditional healing and Self – Actualisation journey. I thought I could escape my healing gift by supporting my family’s rituals without being the one to facilitate other people’s healing processes. My name is derived from the pain, suffering and a challenging journey of accepting my identity as a gay man and an African. My name has been appropriate to the various phases of my evolution as a man and an African child. Those who have known me from my earliest childhood call me “Sipha”, taken from my original – birth name Siphamandla, which means facilitating inner strength and being the agent for change. In my earlier years as a Researcher and a Business Development Consultant, I unleashed a significant amount of anger, fear, anxiety and bitterness on the world and the corporate environment because of the predetermined psychological wounds I had suffered as a Public Administration – Supply Chain Graduate, and at this time I embodied a grinding force and all other qualities often identified as being desirable for growth, although their potential to destroy the African soul and one’s being is never mentioned.
Being born in the village of Maphephetheni, facing Inanda Dam, the only way to escape the rural lifestyle was through education and moving into the city to chase dreams that are bigger than your current. However, for me, I was told from a very young age that there is no way I could escape my gift of being a Sangoma. My parents, sitting in a reading with the late healer, Bab’Hlomuka, said it was obvious that my childhood sicknesses were a call to become a Sangoma. Just as any other ordinary villager, I dreamt that one day I would escape my rural upbringing, not the teachings but the way I would live my life. I completed my university studies in record time with reasonable results and I went straight to get trained as a graduate in Knowledge Management Facilitation. Post that, I moved to the bigger city where the majority of South Africans, including other African youngsters has opted as a place of growth, prosperity and success – Johannesburg.
I wouldn’t have accepted my gift if everything was ‘normal’ in the bigger city. As my growth was concerned, I had a series of events that did not make sense to a normal human being so I decided to take my luggage and laptop bag and hit the road back home to see my parents. On the next day, I was advised to go seek help. That’s when I found myself kneeling down, asking for intwaso. As dramatic as the event was, it felt so real and authentic in a way that my connection with my Ancestors was felt for the very first time after denying my being.
I have matured into being a man of nobility and a facilitator for self-actualisation, change and family adviser through the application of Indigenous Knowledge Systems. I have fully embraced my calling to channel family development and restoration through the different African Indigenous Knowledge Systems, that ability to tap into the spiritual aura – by being guided by the Holy Spirit and both my Ancestors and those of the patient for the day. I have become the one who grinds and mix traditional medicine and perform all the ritual events at my patients’ houses, pleading to God and Ancestors for peace, growth and prosperity. In the African essence, being a healer means that you carry other people’s pains and allow them to be vulnerable in order to heal, grow and learn to love themselves, regardless of their sexual identity because gender restriction never existed in Africa. It is all foreign and very Western. If the world has to learn best practices from us, “it is our ability to build human relationship”– Steve Biko
Being born by of a life-resisting traditional healer – my father who thought was smart enough to escape the gift of being the chosen resident healer, I, myself went through hell and back thinking that Christianity would save me from my predetermined Calling of being an African Spiritualist. I have in turn allowed myself to explore both the corporate and consulting environment but none was fulfilling enough than that one evening when I decided to ride on the late Greyhound Bus, around 22:30 from the Johannesburg Park Station. Little did I know that this was the beginning of a more fulfilling life for myself and those around me. This was the beginning of my God’s and Ancestral calling. He who nourishes himself through prayer, serve his community and all the loved ones is a true definition of Ubuntu. That was the beginning of my fulfilling life.
Many are gifted but very few are chosen to heal and take the bigger responsibility of facilitating African rituals. There is a growing number of homosexual people turning into being Sangomas. The only difference between a gifted person and a healer is their ability to read, advise and facilitate all the necessary series of events that will lead into healing. Anyone can be gifted in different ways. Also, we need to understand that there is nothing wrong with embracing our African Identity for as long as we do not try to buy Ubungoma or fake it for the benefit of self-importance. Being a healer requires a lot of dedication, discipline and ability to walk the healing journey with those that are seeking healing through their African Identity. We cannot fake or imitate other healers to make a difference. It is a calling not a trend. | https://exit.co.za/2021/05/31/healing-a-gift-or-a-trend/ |
Author(s):
Lee H. Silverstein, DDS, MS, FACD, FICD;Michael D. Lefkove, DDS, Bill Matheny, CDT
Date Added:
1/1/1994
Oral Hygiene and Maintenance of Dental Implants
Long-term predictability of dental implants and their associated restorations has been demonstrated. As the number of patients treated with dental implants continues to grow, dentists must accept the challenges of maintaining these sometimes complex restorations. Proper monitoring and maintenance is essential to ensure the longevity of the dental implant and its associated restoration through a combination of appropriate professional care, evaluation, and effective patient oral hygiene. The value…
Using Cross-Sectional Tomography to Perform Exploratory Radiography
Since osseointegration was first introduced by Branemark, dental implants have been used increasingly to replace missing teeth. The high predictability of implant success has been well documented. Unfortunately, there are numerous failures in implant dentistry. The primary failure on endosseous dental implants include improper diagnosis, treatment planning, and/or sequenceing; poor periodontal tissue management and/or maintenance; improper implant position at surgery; and aesthetic requirements…
The Utilization of Advanced Technology as an Instructional Tool
As the practice of dentistry has evolved, significant advances have been realized in the success and predictability of technical procedures, the efficacy of instrumentation, and the means by which information is distributed. Interactive CD-ROMs and videos that guide viewers through selected restorative techn iques are currently being developed as instructional tools for contemporary medical and dental professionals. In conjunction with collegiate universities, pioneering dental operataries have…
What Every Dentist Needs to Know About TM Disorders
Temporomandibular disorders (TMD) are a group of musculoskeletal disorders of the masticatory system. These disorders are common and dentists are the primary care providers. Therefore every dentist should have a sound understanding of TMD so that the most appropriate care will be selected for the patient. This presentation will overview of the role of dentists in the diagnosis and management of TMD.
CBCT in Endodontics: Changing the Landscape of Diagnosis and Clinical Treatment
Radiographic imaging is essential in the diagnosis, treatment planning and follow-up in endodontics. The interpretation of an image can be confounded by a number of factors, including the regional anatomy as well as superimposition of both the teeth and surrounding dento-alveolar structures. As a result of superimposition, periapical radiographs reveal only limited aspects, a 2-dimensional view, of the true three dimensional anatomy. Additionally, there is often geometric distortion of the anatomical structures being imaged with conventional radiographic methods. These problems can be overcome by utilizing small or limited volume cone beam computed tomography (CBCT) imaging techniques which produce accurate 3-dimensional images of the teeth and surrounding dento-alveolar structures. This presentation will highlight the indications, advantages and considerations of the use of CBCT in endodontics.
Tooth Proportions and Color Management in Modern Cosmetic Dentistry
Comprehensive treatment planning of the complex aesthetic restorative case involving teeth and implants can be challenging. The key to success is to understand and develop predictable strategies in patient care. This presentation will focus on diagnosis of dental and gingival architecture discrepancies. Solutions will focus on interdisciplinary treatment, including orthodontics, periodontics, and restorative dentistry. The latest research in these areas will be presented as well as innovative instrumentation to obtain these goals.
Why CBCT Guided Implant Surgery & Treatment Planning for Your Patients: A Restorative Roadmap to Success
This presentation will discuss the advantages of using cbct, accuracy of guided surgery, and advantages of guided implant surgery to help achieve a predictable result for a patient driven treatment.
OCCLUSION: Can We Possibly Simplify It? - Part 3
Over the past 20 years, many of us have been confused, frustrated, unsure and crazy about ... “How do I get my occlusion philosophy on the right path?”. Using our SOT methods and Level 1-10 Occlusion Classification we can show you how to become successful in the “Occlusion” of your patients.
Spend an hour with us and open up a whole new world of occlusion philosophy and understanding. This is the real deal!
From 2D to 3D: The Benefits of 3D-X-ray in the Different Fields of Dentistry
CBCT(Cone Beam Computed Tomography) has developed in the last years from a highly specialized used subject used mainly by specialized surgeons and implantologists to a wide field of indications, used mostly by general practitioners, periodontists, endodontists, general implantologists and orthodontists. The picture quality has increased drastically so the 3-D X-ray techniques are able to show aspects that 2-D X-ray-techniques are unable to present. 3-D X-ray systems are linked today to other diagnostic and electro-mechanical systems as there are automaticised software measure and diagnostic tools, intra and extra-oral scanning systems and CAD-CAM-milling-systems. That increases the diagnostic and treatment possibilities this systems offers to the users.
To view this dental publication or article, you must be a registered user of Dental XP. If you are already a member, click here to login.Registration is free and only takes several minutes. Dental XP will never spam you, or sell your information. | http://www.dentalxp.com/article/laboratory-technology-108814.aspx |
The ePest surveillance app is android based application which is maintained by the National Plant Protection Centre (NPPC), Department of Agriculture, under the Ministry of Agriculture and Forests. The main purpose is to collect and share real-time information on pests of Agricultural crops and send data via internet. It is connected to a central server that will allow rapid data entry, collation and analysis, and makes the data reports available in real time to the participating Gewogs, Dzongkhags and Research Centres. Any desired combination of qualitative and quantitative outputs can be generated, that may be used to develop strategic pest management plans. As the system gathers and store information for any given time period, it will allow the to study the trend of pests occurrence with reference to contributing factors such as climate change and changing crop production system. The trend in pest occurrence under variable climatic conditions will enable us to develop pest forecasting and Early Warning system. The application is compatible with android version 6 and above only.
The application was developed with financial assistance from FAO TCP project: Strengthening of the e-agriculture environment and developing ICT-mediated agricultural solutions for countries in Asia-Pacific.
The link to application in playstore is as follows;
https:/
NB: Interested Researcher or Extension official may write to NPPC ([email protected]) requesting for the user credential. | http://www.moaf.gov.bt/epest-surveillance-application-in-google-playstore/ |
NIGERIA VEGETATION Nigeria is a large country with varying vegetation belts. The variations are found from North to South with the belts running from East to West. Climatic factors such as rainfall, temperature, and relative humidity account for these variations, other factors include topography and human activities on land. The type of agricultural activities to be engaged in a particular area depends on the environment. NIGERIAN VEGETATION BELTS There are two major types of vegetation in Nigeria. These are the ; Forest zones Savanna zones FOREST ZONES : The forest vegetation is found in the southern part of the country and comprises of : a. Mangrove forest b. Rain forest MANGROVE FOREST: It is found around swamps of the coastal creeks, estuaries and lagoons of southern Nigeria - Trees found are : red and white mangroves ,palm and lianas (climbing and twining plant) - Animals found are: fish, crocodiles, snakes and birds.
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B. RAIN FOREST: This area is characterized with rainfall of about 1500mm-2000mm within 8-9 months of rainfall - Found around Ogun ,Oyo , Ondo, Delta, Anambra, Akwa Ibom Trees found in this area are oil palm ,iroko, mahogamy, rubber, walnut,obeche. Animals found in this area are, monkeys, antelopes, wart-hogs, snails,grasscutters e.t.c t SAVANNA ZONES: This covers as much as 80% of the country from the northern edge of the rain forest to the southern edge of the Sahara desert. The savanna zone is subdivided into : a. Derived savanna b. Guinea savanna c. Sudan savanna d. Sahel savanna (A) DERIVED SAVANNA : In this zone, farming activities have combined to degrade the original forest vegetation, leaving behind some fire-tolerant savanna species and a few forest trees. Animals found in the derived savanna include antelopes, giant rats, monkey e.t.c (B) GUINEA SAVANNA : This is the largest vegetation belt in Nigeria: It covers the sparsely populated areas of the middle belts. This region is characterized by natural grassland, sparse woodland or trees. This region is dominated by tubers and grain crops. Animals found here include large animals like buffaloes, elephant, lions kept in game reserve, while smaller animals like giant rats , rabbits and wild cats etc. move about freely.
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© SUDAN SAVANNA: This area is characterized by:
sparsely distributed short trees, with short and seasonal grass cover Rainfall last only 2-3 months and relative humidity is low. Long and more severe dry season or period than the guinea savanna Feathery grasses and give a continuous land cover Common plant found is baobab and shea butter Animals found are similar to those of the guinea savanna but fewer in number due to lack of food(pasture) (D) SAHEL SAVANNA: This is the most northern vegetation zone, found in the Eastern corners of Kano and Borno states. It is characterized with: Barely 500mm of rainfall annually with about 9-10 months of dry season. Very sparse vegetation ,with sparse thorny trees plants found varying from low growing shrubs in some part ,trees varieties include raphia palm acacia and the major crops are millet and sorghum,while vegetables and sugar cane are grown along the river bed Note: irrigation is widely practised in this area due to the inadequate water supply. ASSIGNMENT State the two major vegetation zones in Nigeria Mention the savanna sub zones List 5 common animals and plants found in the rain forest zones.
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connexion with ordinary street architecture. It is significant of the increased attention accorded to street architecture, that the most important architectural event in England at the very close of the 19th century, was the outlay of £2000 by the London County Council, in fees to eight architects for designs for the front of the proposed new streets of Kingsway and Aldwych. The idea was to treat these streets as comprehensive architectural designs with a certain unity of effect. Unfortunately this idea was abandoned for merely commercial reasons, it being feared that there would be a difficulty in letting the sites if tenants were required to conform their frontages to a general design. In the case of Aldwych, which is a crescent street, this decision was fatal. A crescent loses all its effect unless treated as a complete and symmetrical architectural design.
Fig. 107.—House in Buckingham Gate, London. (R. Blomfield.)
The competition for the Queen Victoria Memorial, consisting of a processional road from Whitehall to Buckingham Palace, culminating in a sculptural trophy in front of the palace, attracted a great deal of attention in 1901. Of the five invited competitors—Sir Aston Webb (b. 1849), T. G. Jackson, Ernest George (b. 1839), Sir Thomas Drew (b. 1838), and Sir Rowand Anderson (b. 1834) the two latter representing Ireland and Scotland respectively,—Sir Aston Webb’s design was selected, and unquestionably showed the best and most effective manner of laying out the road, as well as a very pleasing architectural treatment of the semicircular forecourt in front of the palace, with pavilions and fountain-basins symmetrically spaced; but some of this was subsequently sacrificed on grounds of economy. The building, a triumphal arch flanked by pavilions, forming the entry to the processional road from Whitehall, is a dignified design.
Fig. 108.—House in
In France, still the leading artistic nation of the world, the art of architecture has been in a most flourishing and most active state in the most recent period. It is true that there is not the same variety as in modern English Recent French architecture. architecture, nor have there been the same discussions and experiments in regard to the true aim and course of architecture which have excited so much interest in England; because the French architects, unlike the English, know exactly what they want. They have a “school” of architecture; they adhere to the scholastic or academic theory of architecture as an art founded on the study of classic models; and on this basis their architects receive the most thorough training of any in the world. This predominance of the academic theory deprives their architecture, no doubt, of a good deal of the element of variety and picturesqueness; a French architect pur sang, in fact, never attempts the picturesque, unless in a country residence, and then the results are such that one wishes the attempt had not been made. But, on the other hand, modern French architecture at its best has a dignity and style about it which no other nation at present reaches, and which goes far to atone for a certain degree of sameness and repetition in its motives; and living under a government which recognizes the importance of national architecture, and is willing to spend public money liberally on it (with the full approbation of its public), the French architects have opportunities which English ones but seldom enjoy—the predominant aim with a British government being to see how little they can spend on a public building. The two great Paris exhibitions of 1889 and 1900 may be regarded as important events in connexion with architecture, for even the temporary buildings erected for them showed an amount of architectural interest and originality which could be met with nowhere else, and which in each case left its mark behind it, though with a difference; for while in the 1889 exhibition the main object was to treat temporary structures—iron and concrete and terra-cotta—in an undisguised but artistic manner, in those of the 1900 exhibition the effort was to create an architectural coup d’œil of apparently monumental structures of which the actual construction was disguised. In spite of some eccentricities the amount of invention and originality shown in these temporary buildings was most remarkable; but fortunately the exhibition left something more permanent behind it in the shape of the two art-palaces and the new bridge over the Seine. The two palaces are triumphs of modern classic architecture; the larger one (by MM. Thomas, Louvet and Deglane) is to some extent spoiled by the apparently unavoidable glass roof, the smaller one, by M. Girault, escapes this drawback, and, still more refined than its greater opposite, is one of the most beautiful buildings of modern times; the central portion is shown in Plate XIV., fig. 130. The architectural pylons, with their accompanying sculpture, which flank the entries to the bridge, are worthy of the best period of French Renaissance. Thus much, at least, has the 1900 exhibition done for architecture. | https://en.m.wikisource.org/wiki/Page:EB1911_-_Volume_02.djvu/476 |
Hundreds of West Norfolk children take part in Rotary music show
More than 200 youngsters showed off their musical talents and impressed the audience at this year’s Schools Make Music concert on Tuesday night.
Taking place at Lynn’s Corn Exchange and compèred by KLFM’s Simon Rowe, the show featured students from Greyfriars Primary School, Reffley Community Primary School, West Lynn Primary School and Downham Preparatory School.
School's Make Music at The Lynn Corn Exchange''Greyfriars Primary
A total of 220 children from years four to 13 delighted the audience and showed their sheer enjoyment in performing, with all four schools coming together to perform as one at the end of the first half as a surprise.
Adrian Parker, president of the Rotary of King’s Lynn Trinity, who organised the event, said: “This is our 21st annual concert at the Corn Exchange. We organise them to showcase the musical talent of the teachers and pupils of West Norfolk Schools and Youth Groups.
“Every year the youngsters have been co-ordinated by Derek Oldfield and for his support over the years our Club has presented him tonight with Rotary’s Paul Harris Fellowship Award with sapphire – a special distinction.” | |
example sum (using more than 1 bit):
1 0 1 0 0 1
Why not convert to decimal to check all this really works?
We leave it as an exercise for you to complete the table.
You will probably also want to draw the Karnaugh Maps for the Sum and Carry out circuits.
Then you could go on to design the full adder although this is a circuit well outside the expected range for this course.
What would a full-adder circuit look like when expanded to show all logic gates? Draw it using XOR, OR and AND gates.
For these exercises, construct the truth table , derive the expression (minterms), minimise if possible, using algebra and/or K-maps.
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Adders
Recall that binary addition has the following rules for the addition of two binary digits, A and B:
Following on from the previous page, you should be able to see that the Sum is A XOR B whereas the Carry is A and B, expressed as Boolean algebra:
Sum = A and B
Carry = A xor B
The half-adder circuit with one XOR and one AND gate is shown.
When adding binary numbers that have more than 1 bit, the carry must be added to the next column on the left, a full-adder has a truth table like the following:.
A full adder is constructed from 2 half adders with the carry from each half adder going to an OR gate. Schematically:
Exercise
The following schematic circuit is a 2-to-1 line multiplexer, if C is 0 then -Y=A else Y=B:
1. Draw the truth table and derive the algebraic expression for the circuit. Construct the circuit using appropriate gates.
2. Design a circuit that compares three inputs A, B and C and whose output Y is a one if all inputs are equal.
3. Design a circuit that compares the same three inputs as above but outputs a one if any two out of the three inputs are a 1.
3. Design a circuit that compares the same three inputs as above but outputs a one if an odd number of 1's is input. What could this circuit be used for? Have you seen it before?
related: [ Topic 4 home | previous: circuits ]
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The COVID-19 pandemic has disrupted the consumer goods market in Sub-Saharan Africa, with recovery expected to take place over time. Consumers expenditure has been negatively affected, as value seeking consumers shift to essential products. The acceleration of e-commerce penetration is expected to continue over the long-term as shifts in consumer behaviour become part of the ‘New Normal’.
Consumers have become increasingly mindful of their expenditure and are expected to persist in seeking value for money. Essential goods such as staple foods, basic cleaning materials and vitamins and dietary supplements will take priority as consumers mitigate the long-term economic impact of Coronavirus (COVID-19) as they continue to feel the pressure of reduced disposable income.
The pandemic further fast-tracked existing strong e-commerce growth. It is expected to continue its strong growth trajectory, registering double-digit growth over the long term. Heavily supported by m-commerce in a region where mobile phones are the primary means of connected to the internet, the channel will be critical in any marketing mix. However, consumers will continue to buy from traditional channels such as open markets as they meet consumers’ need for value in countries such as Nigeria and Kenya.
The shift in how and where especially professionals buy and consume goods, is likely to lead to a permanent change in consumption occasions. Many consumers are expected to continue to work from home, at least partially, leading to increased hometainment and less in-store consumption. However, this creates strategic opportunities across products and services.
The increased emphasis on local consumption due to lockdown regulations is expected to continue post-pandemic. Consumers are in part driving the shift as they mindfully choose local over imported goods. Furthermore, government legislation aimed at reviving and local economic stimulus coupled with the increased cost of imported goods due to currency exchange volatility will also boost local production and consumption. | https://www.euromonitor.com/the-new-normal-for-consumer-goods-in-sub-saharan-africa/report |
Ad valorem taxes are paid annually on motor vehicles. These taxes are collected when a vehicle is registered and thereafter on a monthly schedule determined by the owner’s last name. Ad valorem taxes on vehicles are delinquent and subject to penalty and interest on the first day of the month following an owner’s renewal month.
To understand when a vehicle’s ad valorem taxes are to be paid annually (after its initial registration), follow the charge below:
Renewal month/first letter of last name:
January: A and D
February: B
March: C and E
April: F, G and N
May: H and O
June: M and I
July: P and L
August: J, K and R
September: Q, S and T
October: U, V, W, X, Y and Z
Oct/Nov: National Guard, Commercial and Fleet Vehicles
The tax on vehicles is paid in advance from time of registration until the owner’s renewal month. | https://cullmanrevenuecommissioner.com/vehicle-renewal-schedule/ |
The Tennessee CMP Reinvestment Program developed a Strategic Plan that outlines the areas of program focus to guide the disbursement and use of CMP funds. The Strategic Plan spotlights the short-term goals, long-term goals, and focus areas listed below.
Short Term Program Goals
- By the end of calendar year 2021, the Tennessee CMP Reinvestment Program will provide a collection of resources and trainings related to each focus area on the CMP Reinvestment website for stakeholder use.
- By the end of calendar year 2021, the Tennessee CMP Reinvestment program, in partnership with the Office of Health Care Facilities, will market CMP funds to address one of the following topics: infection control, residents’ rights, person-centered care, and trauma-informed care.
- By end of calendar year 2021, develop multifaceted marketing strategies to engage stakeholders, encourage effective proposals, and increase awareness of the CMP Reinvestment Program.
- By the end of calendar year 2021, host a Parade of Programs for stakeholders and community partners in order to highlight collaboration, encourage support of existing funded projects, increase the quality of proposals, and promote CMP funding opportunities.
- Increase the quality of proposals with a high likelihood of CMS approval by the year 2022 as measured by the number of proposals received, percent sent to CMS, and percent approved by CMS.
- Increase the annual amount of funding awarded per fiscal year to qualified applicants.
Focus Areas
The CMP Reinvestment Program follows a Quality Assurance Performance Improvement (QAPI) approach utilizing multiple clinical measures to target funding priorities. The program’s 2022 focus areas are as follows:
1. Healthcare-Associated Infections (HAI)
2. Staff Retention
3. Preventable Hospitalizations
4. Person-Centered Care and Trauma Informed Care
5. Residents’ Rights
a. Elder Abuse, Neglect, and Exploitation
b. Alzheimer’s disease and other dementias
Funding focus areas were selected utilizing CMS and state priorities which impact the quality of care and quality of life of nursing home facility residents. Healthcare-associated infection (HAI) measures show how often patients in a particular facility contract infection during the course of their medical treatment. According to CMS, when following guidelines for safe care, these infections can often be prevented. Improved staff retention will allow for the consistent assignment of nursing home staff, which is known to be a component of high-quality resident care. Projects that focus on decreasing the turnover rate of direct care staff, which in turn will improve resident care, could lead to an improvement in resident satisfaction. By utilizing CMP Reinvestment funds to implement initiatives to improve quality measures (falls, preventable hospitalizations, etc.), resident care and quality of life would also improve. More than 110,000 Tennesseans have Alzheimer's. Due to the growing number of individuals aged 65 and older diagnosed with Alzheimer's disease and related dementias, the Tennessee CMP Reinvestment Program and CMP Reinvestment Advisory Committee decided to include it as a funding focus area. Trauma survivors, including veterans, survivors of large-scale natural and human-caused disasters, Holocaust survivors and survivors of abuse, are among those who may be residents of long-term care facilities. For these individuals, the utilization of trauma-informed approaches is an essential part of person-centered care projects. CMS Requirements for Long-term Care Facilities, 42 CFR § 483.10 – Residents rights: Residents’ Rights are guaranteed by the federal 1987 Nursing Home Reform Law. Elder abuse projects would strengthen facility staff knowledge and education to better identify, address and prevent elder abuse, neglect, and exploitation in the nursing home population, thereby improving both the quality of life and the quality of care of nursing home residents. | https://www.firesafekids.state.tn.us/health/health-program-areas/nursing-home-civil-monetary-penalty--cmp--quality-improvement-program/redirect-cmp/cpm-strategic-plan.html |
Each month, we gather in mindfulness, to develop and deepen our own well-being practice, so that we can live our lives from a place of equanimity, non-reactivity and calm. The foundation of our practice is based on four core concepts: gentleness, non-violence, compassion and mindfulness. Each session starts with simple clearing, centering and grounding exercises, a moment of inspirational poetry, followed by different artistic or meditation activities that help you to discover, release, or heal and restore. This is an interactive and experiential session where participation and questions are welcomed. Participants often leave with greater clarity and understanding.
October 2022: Mindful Choices
When conflicting interests arise, we may be plagued by doubt ranging from are we making the right choices for ourselves or for others to how do we deliver the message or how do we even aspire to get to where we want to be. Inspired by the words of author Robert Louis Stevenson who said, “To know what you prefer, instead of humbly saying yes to what the world tells you ought to prefer, is to have kept your spirit alive.” Mindful questioning allows us to unravel the core issues. Mindful delivery allows us to do so with grace and compassion. Join this session to reflect and practice the art of making mindful choices. Participants often leave with greater clarity. | https://www.showtimeon.com/event/mindfulness-for-all-mindful-choices-4469716832 |
Ł[[L]{}]{} [$\tilde{\phantom{a}}$]{}
[**The Laser Driven Vacuum Photodiode**]{}\
Kirk T. McDonald\
[*Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544*]{}\
(Sept. 26, 1986)
Problem
=======
A vacuum photodiode is constructed in the form of a parallel plate capacitor with plate separation $d$. A battery maintains constant potential $V$ between the plates. A short laser pulse illuminates that cathode at time $t = 0$ with energy sufficient to liberate all of the surface charge density. This charge moves across the capacitor gap as a sheet until it is collected at the anode at time $T$. Then another laser pulse strikes the cathode, and the cycle repeats.
Estimate the average current density $\ave{j}$ that flows onto the anode from the battery, ignoring the recharing of the cathode as the charge sheet moves away. Then calculate the current density and its time average when this effect is included.
Compare with Child’s Law for steady current flow.
You may suppose that the laser photon energy is equal to the work function of the cathode, so the electrons leave the cathode with zero velocity.
Solution
========
The initial electric field in the capacitor is ${\bf E} = -V/d\hat{\bf x}$, where the $x$ axis points from the cathode at $x = 0$ to the anode. The initial surface charge density on the cathode is (in Gaussian units) $$\sigma = E/4 \pi = - V/4 \pi d.
\label{s1.6}$$ The laser liberates this charge density at $t = 0$.
The average current density that flows onto the anode from the battery is $$\ave{j} = - {\sigma \over T} = {V \over 4 \pi d T}\, ,
\label{s1.6a}$$ where $T$ is the transit time of the charge across the gap $d$. We first estimate $T$ by ignoring the effect of the recharging of the cathode as the charge sheet moves away from it. In this approximation, the field on the charge sheet is always $E = -V/d$, so the acceleration of an electron is $a = -eD/m =eV/dm$, where $e$ and $m$ are the magnitudes of the charge and mass of the electron, respectively. The time to travel distance $d$ is $T = \sqrt{2 d/a} = \sqrt{2 d^2 m /eV}$. Hence, $$\ave{j} = {V^{3/2} \over 8 \pi d^2} \sqrt{2 e \over m}.
\label{s1.6b}$$ This is quite close to Child’s Law for a thermionic diode, $$j_{\rm steady} = {V^{3/2} \over 9 \pi d^2} \sqrt{2 e \over m}.
\label{s1.6c}$$
We now make a detailed calculation, including the effect of the recharging of the cathode, which will reduce the average current density somewhat.
At some time $t$, the charge sheet is at distance $x(t)$ from the cathode, and the anode and cathode have charge densities $\sigma_A$ and $\sigma_C$, respectively. All the field lines that leave the anode terminate on either the charge sheet or on the cathode, so $$\sigma + \sigma_C = - \sigma_A,
\label{s1.7}$$ where $\sigma_A$ and $\sigma_C$ are the charge densities on the anode and cathode, respectively. The the electric field strength in the region I between the anode and the charge sheet is $$E_I = - 4 \pi \sigma_A,
\label{s1.8}$$ and that in region II between the charge sheet and the cathode is $$E_{II} = 4 \pi \sigma_C.
\label{s1.9}$$ The voltage between the capacitor plates is therefore, $$V = - E_I (d - x) - E_{II} x = 4 \pi \sigma_A d - V {x \over d}\, ,
\label{s1.10}$$ using (\[s1.6\]) and (\[s1.7\]-\[s1.9\]), and taking the cathode to be at ground potential. Thus, $$\sigma_A = {V \over 4 \pi d} \left( 1 + {x \over d} \right), \qquad
\sigma_C = - {V x \over 4 \pi d^2}\, ,
\label{s1.11}$$ and the current density flowing onto the anode is $$j(t) = \dot \sigma_A = {V \dot x \over 4 \pi d^2}.
\label{s1.12}$$ This differs from the average current density (\[s1.6a\]) in that $\dot x/d \neq T$, since $\dot x$ varies with time.
To find the velocity $\dot x$ of the charge sheet, we consider the force on it, which is due to the field set up by charge densities on the anode and cathode, $$E_{{\rm on}\ \sigma} = 2 \pi(-\sigma_A + \sigma_C)
= -{V \over 2d} \left( 1 + {2x \over d} \right).
\label{s1.13}$$ The equation of motion of an electron in the charge sheet is $$m \ddot x = -e E_{{\rm on}\ \sigma}
= {eV \over 2 d} \left( 1 + {2x \over d} \right),
\label{s1.14}$$ or $$\ddot x - {e V \over m d^2} x = {e V \over 2 m d}.
\label{s1.15}$$ With the initial conditions that the electrons start from rest, $x(0) = 0 = \dot x(0)$, we readily find that $$x(t) = {d \over 2} (\cosh kt - 1),
\label{s1.16}$$ where $$k = \sqrt{e V \over m d^2}.
\label{s1.17}$$ The charge sheet reaches the anode at time $$T = {1 \over k} \cosh^{-1} 3.
\label{s1.18}$$
The average current density is, using (\[s1.6a\]) and (\[s1.18\]), $$\ave{j}= {V \over 4 \pi d T}
={V^{3/2} \over 4 \pi \cosh^{-1}(3)\ d^2}
\sqrt{e \over m}
= {V^{3/2} \over 9.97\ \pi d^2} \sqrt{2 e \over m}.
\label{s1.21}$$
The electron velocity is $$\dot x = {d k \over d} \sinh kt,
\label{s1.19}$$ so the time dependence of the current density (\[s1.12\]) is $$j(t) = { 1 \over 8 \pi} {V^{3/2} \over d^2} \sqrt{e \over m} \sinh kt
\qquad (0 < t < T).
\label{s1.20}$$
A device that incorporates a laser driven photocathode is the laser triggered rf gun [@bnlgun].
[99]{} K.T. McDonald, [*Design of the Laser-Driven RF Electron Gun for the BNL Accelerator Test Facility*]{}, IEEE Trans. Electron Devices, [**35**]{}, 2052-2059 (1988).
| |
Symmetric designs are found in virtually every culture, and are interesting to students across the grades. We will use that as a foundation for lessons about essential and enrichment math topics for grades 6-8. This approach will allow us to build on student creativity while furthering their visual sense and their mathematical growth.
We will explore line and rotational symmetry with activities using manipulatives and free online platforms. We will discuss rosette symmetry (finite figures), frieze symmetry (infinite designs that extend in one dimension), and wallpaper symmetry (two-dimensional designs and tessellations).
Along the way, we will analyze examples from all over the world and touch on the following concepts: special triangles and quadrilaterals, regular polygons, factors and multiples, rigid motions, and dilation.
Participants will receive the needed manipulatives and handouts in the mail. For some of the work we will be using online manipulatives. Some of the content will be drawn from the Symmetry material on my website.
Participants will also get to join short sessions on assorted topics, and do math together as part of a Math Teachers' Circle. | https://summer.mathedpage.org/symmetry |
Transference is a simple term to describe the process of unconsciously transferring feelings. When therapy patients get involved in a regular treatment plan, especially one that involves a higher frequency of sessions per week, they often start having feelings about the therapist that are similar to feelings they had or have about other important people in their lives.
I talk about this with patients by explaining, “Sooner or later, you will have feelings about me that you have toward other significant people in your life.” This is useful because this phenomenon turns the therapy into a “living lab” where the patient’s old feelings and conflicts can be re-worked with the therapist in an alive and meaningful way, over and over again, leading to greater understanding of issues in the patient’s mind and improvement in his or her intimate relationships.
I was a few minutes late for a session with a patient, Ellie, who had started therapy about six months ago. I apologized when I opened the waiting room door. She said at once, rather brightly, “Oh, it’s no problem at all; these things happen.” I remained quiet and waited to hear what else Ellie might say. She started telling me about a friend she met for dinner last night. Her friend “by chance” ran into difficulties and arrived late for their dinner together. After a brief silence, she told me in detail about her boss (a woman) being ten minutes late for an important meeting earlier that day. “Really created a problem with our client,” Ellie exclaimed.
I noted these two stories about people being late and keeping her and others waiting. I recapped that I had also been late today, but she had been very understanding and pleasant about my lateness. I then asked if that was her usual response to people being late or keeping her waiting.
This is a tiny example of the many interactions that take place between patient and therapist. In sum, the patient’s life history and old relationships are re-experienced in therapy with an experienced, knowledgeable, and empathic therapist. The therapist conveys her understanding of these matters to the patient; in turn, the patient can emotionally understand the old hurts, childhood pain, fear of loss, or fear of retaliation from important people. This ultimately decreases the patient’s suffering and leads to a happier life.
Check our blog in the coming weeks for more tips and helpful articles. At the Mel Bornstein Clinic, our goal is to offer a safe, confidential, and trustworthy treatment setting for all patients. For more information, please call Marla McCaffrey, LMSW at (248)851-7739. | https://www.melbornsteinclinic.org/blog/2018/10/23/usefulness-of-transference-during-therapy |
The Outlook for Ovarian Cancer: Prognosis, Life Expectancy, and Survival Rates by Stage
If you’ve been diagnosed with ovarian cancer, you’re probably wondering about your prognosis. While knowing your prognosis can be helpful, it’s only a general guideline. Your individual outlook will depend on many factors, such as your age and overall health.
One of the first things you’ll want to know is the stage of your ovarian cancer. Staging is a way of describing how far the cancer has spread and can indicate how aggressive your cancer is. Knowing the stage helps doctors formulate a treatment plan and gives you some idea of what to expect.
Ovarian cancer is primarily staged using the FIGO (International Federation of Gynecology and Obstetrics) staging system. The system is based mainly on a physical exam and other tests that measure:
the size of the tumor
how deeply the tumor has invaded tissues in and around the ovaries
the cancer’s spread to distant areas of the body (metastasis)
If surgery is performed, it can help doctors more accurately determine the size of the primary tumor. Accurate staging is important in helping you and your doctor understand the chances that your cancer treatment will be curative.
These are the four stages for ovarian cancer:
Stage 1
In stage 1, the cancer has not spread beyond the ovaries. Stage 1A means the cancer is only in one ovary. In stage 1B, the cancer is in both ovaries. Stage 1C means that one or both ovaries contain cancer cells and one of the following are also found: the outer capsule broke during surgery, the capsule burst before surgery, there are cancer cells on the outside of an ovary, or cancer cells are found in fluid washings from the abdomen.
Stage 2
In stage 2 ovarian cancer, the cancer is in one or both ovaries and has spread to elsewhere within the pelvis. Stage 2A means it has gone from the ovaries to the fallopian tubes, the uterus, or to both. Stage 2B indicates the cancer has migrated to nearby organs like the bladder, sigmoid colon, or rectum.
Stage 3
In stage 3 ovarian cancer, the cancer is found in one or both ovaries, as well as in the lining of the abdomen, or it has spread to lymph nodes in the abdomen. In Stage 3A, the cancer is found in other pelvic organs and in lymph nodes within the abdominal cavity (retroperitoneal lymph nodes) or in the abdominal lining. Stage 3B is when the cancer has spread to nearby organs within the pelvis. Cancer cells may be found on the outside of the spleen or liver or in the lymph nodes. Stage 3C means that larger deposits of cancer cells are found outside the spleen or liver, or that it has spread to the lymph nodes.
Stage 4
Stage 4 is the most advanced stage of ovarian cancer. It means the cancer has spread to distant areas or organs in your body. In stage 4A, cancer cells are present in the fluid around the lungs. Stage 4B means that it has reached the inside of the spleen or liver, distant lymph nodes, or other distant organs such as the skin, lungs, or brain.
Your prognosis depends on both the stage and the type of ovarian cancer you have.
There are three types of ovarian cancer:
Epithelial: These tumors develop in the layer of tissue on the outside of the ovaries.
Stromal: These tumors grow in hormone-producing cells.
Germ cell: These tumors develop in egg-producing cells.
According to the Mayo Clinic, about 90 percent of ovarian cancers involve epithelial tumors. Stromal tumors represent about 7 percent of ovarian tumors, while germ cell tumors are significantly rarer.
The five-year relative survival rate for these three types of tumors is 44 percent, according to the American Cancer Society.
Early detection generally results in a better outlook. When diagnosed and treated in stage 1, the five-year relative survival rate is 92 percent. Only about 15 percent of ovarian cancers are diagnosed in stage 1.
The Surveillance, Epidemiology, and End Results (SEER) registry program of the National Cancer Institute (NCI) is the authoritative source on cancer survival in America. It collects comprehensive information for different types of cancer in populations within the United States.
The table below is derived from the SEER registry and can help you better understand the rate of survival for your stage of ovarian cancer for each year after diagnosis. Registries use a simplified approach to staging. It roughly correlates with the other staging systems as follows:
Localized: Cancer is limited to the place where it started, with no sign that it has spread. This correlates roughly with Stage 1 disease.
Regional: Cancer has spread to nearby lymph nodes, tissues, or organs. This encompasses Stage 2 and 3 disease described above.
Distant: Cancer has spread to distant parts of the body. This indicates stage 4 disease.
Since fewer women have stage 1 or “localized” ovarian cancer, the overall prognosis for regional or distant disease can be broken down by year since diagnosis. For example, taking all tumor types, for women with distant spread (or stage 4 disease) of ovarian cancer, the percentage of women in the U.S. population surviving 1 year is nearly 69%.
A woman’s lifetime risk of developing ovarian cancer is about 1.3 percent.
In 2016, an estimated 22,280 women in the United States alone will have received a diagnosis for ovarian cancer, and the disease will have caused 14,240 deaths. This represents about 2.4 percent of all cancer deaths. | |
A client brought in their newly purchased 8 week old pup for a check-up. It had been very quiet and started to have fits in the last 24 hours. On examination, the forehead was bulging forward and the eyeballs had slight deviation outwards and downwards.
We suspected it had a congenital condition called hydrocephalus which means "water on the brain". During development in the womb, the central nervous system (CNS), which is composed of the spine and brain, makes a special fluid that protects it from trauma and provides nourishment and lubrication. This fluid is called cerebrospinal fluid (CSF).
CSF is made in the brain. It leaves through some special channels into the spinal cord. The CNS has special areas outside of the brain where excess CSF is filtered off into the bloodstream.
In hydrocephalus, the special channels connecting the brain to the spinal cord have not developed properly and are either too narrow or absent. This means the CSF builds up in the brain and it slowly gets bigger while compressing the surrounding brain tissue. Eventually, you are left with a fluid sac in the middle of the brain that causes serious damage to the surrounding brain tissue which is pressed against the overlying bones of the skull. In a young pup, the soft bones of the skull start to bulge outwards giving rise to the dome shaped head.
Affected individuals can display all types of symptoms e.g. depression, coma, convulsions, weakness, nausea, deviation of the eyeballs.
In this case, we decided to euthanise the pup. In humans, using special diagnostic techniques like cat scans and MRI, they can place special drainage tubes between the brain and spinal cord to relieve the pressure buildup. Unfortunately, this is not available for veterinary surgeons. | http://berryhavenvet.com.au/hospital-cases/medical/hydrocephalus |
The present invention relates a method of rectifying a stereoscopic image pair, and in particular relates to a method of determining a pair of rectification transformations for rectifying the two captured images making up the image pair so as to substantially eliminate vertical disparity from the rectified image pair. The invention is particularly applicable to rectification of a stereoscopic image pair intended for display on a stereoscopic image display device for direct viewing by an observer. The invention also relates to an apparatus for rectifying a stereoscopic image pair.
The principles of stereoscopic displays are well known. To create a stereoscopic display, two images are acquired using a stereoscopic image capture device that provides two image capture devices. One image capture device (known as the "left image capture device") captures an image corresponding to the image that would be seen by the left eye of an observer, and the other image capture device (known as the "right image capture device") captures an image corresponding to the image that would be seen by the right eye of an observer. The two images thus acquired are known as a pair of stereoscopic images, or stereoscopic image pair. When the two images are displayed using a suitable stereoscopic display device, a viewer perceives a three-dimensional image. The stereoscopic image capture device may contain two separate image capture devices, for example such as two cameras. Alternatively, the stereoscopic capture image device may contain a single image capture device that can act as both the left image capture device and the right image capture device. For example, a single image capture device, such as a camera, may be mounted on a slide bar so that it can be translated between a position in which it acts as a left image capture device and a position in which it acts as a right image capture device. As another example, the stereoscopic image capture device may contain a single image capture device and a moving mirror arrangement that allows the image capture device to act either as a left image capture device, or a right image capture device.
One problem with conventional stereoscopic displays is that stereoscopic images can be uncomfortable to view, even on high quality stereoscopic display devices. One cause of discomfort is the presence of vertical disparity within a stereoscopic image pair. Vertical disparity means that the image of an object in one of the stereoscopic images has a different vertical position than the image of the same object in the other stereoscopic image. Vertical disparity arises owing to many kinds of misalignment of the camera systems, and causes discomfort to a viewer. Image rectification is a process for eliminating vertical disparity between the two images of a stereoscopic image pair, so making the resultant stereoscopic image more comfortable to view.
The origin of vertical disparity within a stereoscopic image pair will now be explained with reference to a simplified model that uses a camera set up consisting of two pin-hole cameras, one for recording the image that would be seen by the left eye of the observer and the other for recording the image that would be seen by the right eye of an observer. The left pin-hole camera - that is, the pin-hole camera for recording the image that would be seen by the left eye - consists of a pin-hole 1L and an imaging plane 2L, and the right pin-hole camera - that is, the pin-hole camera for recording the image that would be seen by the right eye - also comprises a pin-hole 1R and an imaging plane 2R.
L
R
In the two camera set-up of Figure 1, the base line 3 is the distance between the pin-hole 1L of the left camera and the pin-hole 1R of the right camera. The optical axis of each camera is the axis that is perpendicular to the imaging plane of the camera and that passes through the pin-hole of the camera. For each camera, the "principal point" is the point 5L, 5R in the imaging plane 2L, 2R of the camera that is nearest to the pin-hole 1L, 1R of the camera. Finally, the effective focal length of each camera is the distance f, f between the pin-hole of a camera and the principal point of the camera.
Figures 2(a) and 2(b) illustrate an ideal stereoscopic recording set up. In an ideal set up, the left and right cameras are identical so that, inter alia, the focal length of the left camera is identical to the focal length of the right camera and the principal point of the left camera is identical to the principal point of the right camera. Furthermore, in an ideal camera set up the optical axis of the left and right cameras are parallel, and are also perpendicular to the base line. For brevity, a camera set up such as shown in Figure 2(a) or 2(b) will be referred to as a "parallel camera set up".
If a stereoscopic image pair is captured with two identical cameras, or other recording devices, arranged precisely in a parallel camera set up, vertical disparity will not occur between the two images of the stereoscopic image pair. However, vertical disparity is introduced into the stereoscopic image pair when the image pair is captured with a non-ideal camera set up. In practice, a typical low-cost stereoscopic camera system is only an approximation to a parallel camera set up. The two cameras in a typical low-cost stereoscopic camera system will in practice have unmatched focal lengths and unmatched principal points, even if the two cameras are nominally identical. Furthermore, the optical axes of the two cameras are likely not to be exactly orthogonal to the base line, and are likely not to be parallel to one another. Such a typical stereoscopic camera system is illustrated in Figure 2(c). Stereoscopic images captured using a camera set up having the defects shown in Figure 2(c) will contain vertical disparity.
The focal length and principal point are sometimes called the "intrinsic" camera parameters, since these parameters relate to a single camera. The rotation and translation are referred to as "extrinsic" camera parameters, since they relate to the way in which one camera of a stereo camera set up is aligned relative to the other camera.
It is known to process stereoscopic images captured using a non-parallel camera set up, in order to reduce vertical disparity. This process is known as "rectification". If the rectification process is completely effective, vertical disparity will be eliminated - and a high quality stereoscopic display can be obtained even though the original images were captured using a non-parallel camera alignment. The rectification process can be thought of as a process for virtually aligning the two cameras, since the rectified images correspond to images that would have been acquired using a parallel camera set-up (assuming that the rectification process was carried out correctly).
Figure 3(a) is a block flow diagram of a prior art rectification process. At step 11 a stereoscopic image pair is captured, and a correspondence detection step is then carried out at step 12 to detect pairs of corresponding points in the two images (that is, each pair consists of a point in one image and a corresponding point in the other image). If there is vertical disparity between the two images, this will become apparent during the correspondence detection step.
At step 13 details of the rectification procedure required to eliminate the vertical disparity between the two stereoscopic images are determined, from the results of the correspondence detection step. At step 14 a pair of rectifying transformations is determined, one transformation for rectifying the left image and one transformation for rectifying the right image. At step 15, the left and right images are operated on by the rectifying transformation determined for that image at step 14; this is generally known as the "warping step", since the left and right images are warped by the rectifying transformations. The result of step 15 is to produce a rectified image pair at step 16. If the rectifying transformations have been chosen correctly, the rectified image pair should contain no vertical disparity. Finally, the rectified images can be displayed on a stereoscopic imaging device at step 17.
The rectifying transformations determined at step 14 will depend on the geometry of the camera set up. Once suitable rectifying transformations have been determined from one captured image pair, therefore, it is not necessary to repeat steps 12, 13 and 14 for subsequent image pairs acquired using the same camera set-up. Instead, a subsequent captured image pair acquired using the same camera set-up can be directly warped at step 15 using the rectifying transformations determined earlier.
Apart from the elimination of vertical disparity within a stereoscopic image pair, rectification is also used in the prior art to simplify subsequent stereoscopic analysis. In particular, the stereoscopic matching or correspondence problem is simplified from a two-dimensional search to a one-dimensional search. The rectifying transformations for the left and right images are chosen such that corresponding image features can be matched after rectification.
Prior art rectification techniques of the type shown generically in Figure 3(a) fall into two main types. The first type of rectification process requires knowledge of the "camera parameters" of the camera set up. The camera parameters include, for example, the focal lengths of the two cameras, the base line, the principal point of each camera and the angle that the optical axis of each camera makes with the base line. Knowledge of the camera parameters is used to estimate appropriate rectifying transformations. Figure 3(b) is a block flow diagram for such a prior art rectification process. It will be seen that the method of Figure 3(b) differs from that of Figure 3(a) in that knowledge of the camera parameters is used at step 13 to estimate the rectifying transformations.
Prior art rectification methods of the type shown schematically in Figure 3(b) are disclosed in, for example, N. Ayache et al in "Rectification of Images for binocular and trinocular stereovision" in "International Conference of Pattern Recognition" pp11-16 (1998), by P. Courtney et al in "A Hardware Architecture for Image Rectification and Ground Plane Obstacle Detection" in "International Conference on Pattern Recognition", pp23-26 (1992), by S. Kang et al in "An Active Multibaseline Stereo System with Real-Time Image Acquisition" Tech. Rep. CMU-CS-94-167, School of Computer Science, Carnegie Mellon University (1994), and by A. Fusiello et al, "Rectification with Unconstrained Stereogeometry" in "Proceedings of British Machine Vision Conference" pp400-409 (1997).
Prior art rectification methods of the type shown schematically in Figure 3(b) have the disadvantage in that they are only as reliable as the camera parameters used to estimate the rectifying transformations. In principle, if the exact camera parameters are used to estimate the rectifying transformations, then the vertical disparity can be completely eliminated. In practice, however, the camera parameters will not be known exactly and, in this case, the rectifying transformations will be chosen incorrectly. As a result, the rectified image pair will still contain vertical disparity.
An alternative prior art rectification method is illustrated schematically in Figure 3(c). This method does not use the camera parameters to determine the appropriate rectifying transformations. Rectification that does not involve use of camera parameters is sometimes referred to as "projective rectification".
In projective rectification, there are degrees of freedom in the choice of the rectifying transformations. Most prior art methods of projective rectification use some heuristics to eliminate these degrees of freedom so as to eliminate all but one pair of rectifying transformations; the one remaining pair of rectifying transformations are then used to rectify the left and right images. The heuristic minimises image distortion, as measured in some way, in the rectified image pair. This prior art method has the feature that the pair of rectifying transformations that is determined does not necessarily correspond to virtually aligning the cameras to give a parallel camera set up. Where the rectified image pair produced by the rectification process is intended for stereoscopic analysis such as stereoscopic correspondence, it is not necessary for the rectifying transformation to correspond to a virtual alignment that gives a parallel camera set-up. However, where the rectified stereoscopic image pair is to be viewed on a stereoscopic imaging device, it is desirable that the rectifying transformation does correspond to a virtual alignment that gives a parallel camera set-up since, if the rectifying transformation does not correspond to a virtual alignment that gives a parallel camera set-up, the perceived three-dimensional image could appear distorted from what would have been observed using a parallel camera set up. For example a rectifying transformation that transforms straight lines in a captured image into curved lines in the rectified image does not correspond to a virtual alignment that gives a parallel camera set-up.
US Patent No. 6 011 863 discloses a method of the general type shown in Figure 3(c) in which an original captured image is projected onto a non-planar surface, so that straight lines in the captured image are transformed to curved lines in the rectified image. As noted above, this transformation does not correspond to a parallel camera alignment.
D. Papadimitriou et al disclose, in "Epipolar Line Estimation and Rectification for Stereoimage Pairs", "IEEE Transaction of Image Processing", Vol. 5, pp672-676 (1996) a rectification method in which the camera rotation is restricted to be about a particular axis only. With such a restricted camera geometry, all the camera intrinsic and extrinsic parameters can be estimated from the correspondence detection. The rectifying transformations can then be determined from the camera parameters. This method is limited to one specific camera geometry.
R. Hartley et al disclose, in "Computing matched-epipolar projections" in "Conference on Computer Vision and Pattern Recognition" pp549-555 (1993), a rectification method using the heuristic that (i) the rectifying transformation for one of the images is a rigid transformation at a specific point (typically the centre of the image) and (ii) the horizontal disparity is minimised. Similar heuristics are used in methods disclosed by R. Hartley in "Theory and Practice of Projective Rectification" in "International Journal of Computer Vision" (1998) and by F. Isgro et al in "Projective Rectification Without Epipolar Geometry" in "Conference on Computer Vision and Pattern Recognition" pp94-99 (1999).
These methods have the disadvantage that the rectifying transformations do not necessarily correspond to a virtual alignment to a parallel camera set-up.
C. Loop et al disclose in, "Computer Rectifying Harmographies for Stereo Vision" "Tech Rep MSR-TR-99-21, Microsoft Research (1999), a rectifying method that uses an heuristic that maintains the aspect ratio and perpendicularity of two lines formed by the mid points of the image boundaries. This rectifying transformations determined by this method again do not necessarily correspond to a virtual alignment to a parallel camera set-up.
Japanese patent Nos. 2058993 and 7050856 describe correcting a stereoscopic video signal to compensate for differences in brightness or colour balance between the left eye video signal and the right eye video signal. These documents do not relate to correcting for vertical disparity between the left eye image and the right eye image.
US patent No. 6 191 809 describes correcting for optical misalignment of the two images of a stereoscopic image pair (for example produced by a stereo electronic endoscope). The citation discloses processing the image data electronically by digitising the two images, and digitally rectifying the images by means of a vertical image shift and/or image size change and/or image rotation in order to correct for any mis-alignment between the two images. However, no details of the rectifying transformations are given.
EP-A-1 100 048, which was published after the priority date of this application, describes a method of processing an image pair that includes an image rectification step. However, no details of the image rectification step are given.
A first aspect of the present invention provides a method of rectifying a stereoscopic image comprising first and second images captured using a respective one of first and second image capture devices, the first and second image capture devices forming a stereoscopic image capture device, the method comprising the step of: determining first and second rectification transformations for rectifying a respective one of the first and second images so as to reduce vertical disparity; wherein the method comprises using statistics of the parameters of the stereoscopic image capture device in the determination of the first and/or second rectification transformations.
The terms "first image capture device" and "second image capture device" are used herein for ease of explanation. It should be understood, however, that the invention may be applied to a stereoscopic image that was captured using a stereoscopic image capture device having a single image capture device that can act as both the first image capture device and the second image capture device as described above.
When the first and second rectification transformations are applied to the first and second images, vertical disparity in the transformed images is eliminated or at least substantially reduced. The rectifying transformations effectively adjust the orientations of the image capture devices, so that the transformed images are images that would have been obtained if the two image capture devices were identical to one another and were correctly aligned relative to one another.
In prior art methods that use knowledge of the parameters of the image capture devices to determine the rectifying transformations, it is assumed that the parameters are known exactly. If the parameters used in the determination of the rectification transformations are not exactly the true parameters of the image capture system, however, the resultant rectification transformations will not eliminate vertical disparity from the rectified image pair. The present invention overcomes this problem by using statistics for the parameters of the image capture devices in the determination of the rectification transformations, rather than assuming that the exact parameters are known for the particular image capture devices used to obtain a stereoscopic image pair. The elimination of vertical disparity from the rectified image pair is therefore accomplished more efficiently in the present invention than in the prior art.
Each rectification transformation may comprise a horizontal shear and scaling component, and the statistics of the parameters of the stereoscopic image capture device may be used in the determination of the horizontal shear and scaling component of the first and/or second rectification transformation.
The method may comprise the steps of: determining the first and second rectification transformations; varying the statistics of the parameters of the stereoscopic image capture device; re-determining the first and second rectification transformations; and rectifying the first and second images using a respective one of the re-determined first and second rectification transformations. This allows a user to alter the parameters of the image capture devices used to determine the rectification transformations.
The method may comprise the further steps of: rectifying at least part of the first image and at least part of the second image using a respective one of the initially-determined first and second rectification transformations; and displaying the rectified parts of the first and second images on the stereoscopic display device. This allows a user to monitor how satisfactory the initial rectification transformations are. Moreover, if this step is carried out on only part of the first and second images the required processing power is reduced.
The method may comprise the further steps of: rectifying at least part of the first image and at least part of the second image using a respective one of the initially-determined first and second rectification transformations; displaying the rectified parts of the first and second images on the stereoscopic display device; and varying the statistics of the parameters of the stereoscopic image capture device on the basis of the display of the rectified parts of the first and second images. If the initial rectification transformations are not satisfactory, a user is able to vary the parameters used to determine the rectification transformations.
The statistics of the parameters of the stereoscopic image capture device may relate to parameters of the first image capture device and/or to parameters of the second image capture device. These are known as "intrinsic" parameters and are a measure of how the first image capture device differs from the second image capture device.
The statistics of the parameters of the stereoscopic image capture device may comprise the mean of the focal length of the first and second image capture devices, and they may comprise the standard deviation of the focal length of the first and second image capture devices.
The statistics of the parameters of the stereoscopic image capture device may comprise the mean of the principal point of the first and second image capture devices, and they may comprise the standard deviation of the principal point of the first and second image capture devices.
The statistics of the parameters of the stereoscopic image capture device may relate to the alignment of the first image capture device relative to the second image capture device. These are known as "extrinsic" camera parameters.
The statistics of the parameters of the stereoscopic image capture device may comprise the mean of the rotation of the optical axis of the first image capture device relative to the optical axis of the second image capture device, and they may comprise the standard deviation of the rotation of the optical axis of the first image capture device relative to the optical axis of the second image capture device.
The first and second rectification transformations may be determined so as correspond to a virtual alignment to a parallel camera set-up.
A second aspect of the invention provides a method of rectifying a stereoscopic image comprising first and second images captured using first and second image capture devices, the first and second image capture devices forming a stereoscopic image capture device, the method comprising the step of: determining first and second rectification transformations for rectifying a respective one of the first and second images so as to reduce vertical disparity; wherein the method comprises determining the first and second rectification transformation so that the first and second rectification transformations correspond to a virtual alignment to a parallel camera set-up.
If the rectifying transformations do not correspond to a virtual alignment to a parallel camera set-up, the resultant three-dimensional image can appear distorted; for example, straight lines in the original object can appear as curved lines in the resultant three-dimensional image. Where the rectified image is intended to be displayed for direct viewing by an observer, such distortion means that the observer will experience discomfort when viewing the rectified image. The present invention prevents the possibility of such distortion, by ensuring that the rectifying transformations correspond to a virtual alignment to a parallel camera set-up.
The method may further comprise the step of using statistics of the parameters of the image capture device in the step of determining the first and second rectification transformations. Rectification transformations that are possible, but unlikely, can be eliminated according to this embodiment of the invention.
The step of determining the first and second rectification transformations may comprise: determining a first component of each of the first and second rectification transformations, the first component of the first rectification transformation and the first component of the second rectification transformation substantially eliminating vertical disparity from the rectified image pair; and determining a second component of each of the first and second rectification transformations so that the first and second rectification transformations correspond to a virtual alignment to a parallel camera set-up. The statistics of the parameters of the stereoscopic image capture device may be used in the step of determining the second components of the first and second rectification transformations.
The statistics of the parameters of the stereoscopic image capture device may relate to the alignment of the first image capture device relative to the second image capture device.
The first image and second image may comprise a still stereoscopic image. Alternatively, the first image and second image may comprise a frame of a stereoscopic video image.
The method may comprise: determining first and second rectification transformations for a first frame of the stereoscopic video image using a method described above; and rectifying subsequent frames of the stereoscopic video image using the first and second rectification transformations determined for the first frame of the stereoscopic video image. This reduces the processing power required.
th
th
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The method may alternatively comprise the steps of: determining first and second rectification transformations for a first frame of the stereoscopic video image according to a method as defined above; rectifying first to N frames of the stereoscopic video image using the first and second rectification transformations determined for the first frame of the stereoscopic video image; determining first and second rectification transformations for an (N + 1) frame of the stereoscopic video image; and rectifying (N + 1) to (2N) frames of the stereoscopic video image using the first and second rectification transformations determined for the (N + 1) frame of the stereoscopic video image. This ensures that any error in determining the rectification transformations for a particular frame will affect only a limited number of frames of the stereoscopic video image.
The method may alternatively comprise the steps of: determining first and second rectification transformations for each frame of the stereoscopic video image according to a method as defined above; and rectifying each frame of the stereoscopic video image using the first and second rectification transformations determined for the that frame. This ensure that any error in determining the rectification transformations for a particular frame will affect only that frame of the stereoscopic video image.
The method may comprise the further step of rectifying the first and second captured images using a respective one of the first and second rectification transformations.
The method may comprise the further step of displaying the first and second rectified images on a stereoscopic display device for viewing by an observer.
means for determining first and second rectification transformations for rectifying a respective one of the first and second images so as to reduce vertical disparity using statistics of the parameters of the stereoscopic image capture device in the determination of the first and/or second rectification transformations.
A third aspect of the present invention provides an apparatus for rectifying a stereoscopic image comprising first and second images captured using a respective one of first and second image capture devices, the first and second image capture devices forming a stereoscopic image capture device, the apparatus comprising:
means for determining first and second rectification transformations for rectifying a respective one of the first and second images so as to reduce vertical disparity, the first and second rectification transformations corresponding to a virtual alignment to a parallel camera set-up.
A fourth aspect of the present invention provides an apparatus for rectifying a stereoscopic image comprising first and second images captured using first and second image capture devices, the first and second image capture devices forming a stereoscopic image capture device, the apparatus comprising:
The apparatus may further comprise means for rectifying the first and second captured images using a respective one of the first and second rectification transformations.
The apparatus may comprise a programmable data processor.
A fifth aspect of the present invention provides a storage medium containing a program for the data processor of an apparatus as defined above.
Figure 1 is a schematic perspective view of an image capture device for recording a stereoscopic image pair;
Figure 2(a) is a plan view of the image capture device of Figure 1;
Figure 2(b) is a schematic illustration of a parallel camera set up for recording a stereoscopic image pair;
Figure 2(c) is a schematic illustration of a non-parallel camera set up for recording a stereoscopic image pair;
Figure 3(a) is a block flow diagram of a prior art rectification process;
Figure 3(b) is a schematic block view of a further prior art rectification process;
Figure 3(c) is a schematic block diagram of a further prior art rectification process;
Figure 4(a) and 4(b) illustrate the notation used to describe the camera set up;
Figure 5 is a schematic flow diagram of a rectification method incorporating a first embodiment of the present invention;
Figure 6 is a schematic flow diagram of a rectification method incorporating a second embodiment of the present invention;
Figure 7 is a schematic flow diagram of a rectification method incorporating a third embodiment of the present invention;
Figure 8 is a schematic flow diagram of a rectification method incorporating a fourth embodiment of the present invention;
Figure 9 is a schematic flow diagram of a rectification process incorporating a fifth embodiment of the present invention;
Figure 10 is a schematic illustration of the decomposition of a rectifying transformation into projective similarity components and horizontal shear and scaling components; and
Figure 11 is a block schematic illustration of an apparatus according to an embodiment of the invention..
Preferred features of the present invention will now be described by way of illustrative example with reference to the accompanying figures, in which:
Figure 5 is a schematic flow diagram of a method incorporating to a first embodiment of the present invention. Figure 5 illustrates an entire rectification process, from initial capture of the image pair to display of the rectified image on a suitable stereoscopic imaging device. The determination of the rectification transformations in Figure 5 is carried out according to the present invention.
The method of Figure 5 is intended for use with a pair of captured images that form a stereoscopic image pair, and this pair of images forms one input to the method. Statistics of parameters of the set-up of the stereoscopic image capture device used to capture the pair of images (hereinafter referred to as the "camera parameters" for convenience) form the other input. According to the first aspect of the invention, the statistics of the camera parameters are used in the determination of the rectification transformations. (Mathematically the rectification transformations are homographies, which are linear projective transformations that preserve straightness and flatness, but the general term rectification transformations will generally be used herein.)
A suitable image capture device for use with the method of Figure 5 is a stereo-camera consisting of a pair of digital cameras although, in principle, any stereoscopic image capture device can be used. An example of a suitable stereoscopic display device for displaying the stereoscopic image is an auto-stereoscopic display of the type disclosed in European Patent Publication EP-A-0 726 48, although other imaging devices may be used.
t
R
R
The co-ordinate system used in the description of the present invention is shown in Figure 4(a). In Figure 4(a) the two cameras forming the stereoscopic camera are depicted as pin-hole cameras for simplicity. The origin of the co-ordinate system is chosen to be the pin-hole of one camera, in this example the pin-hole 1L of the left camera. The operation is the translation required to translate the pin-hole 1L of the left camera onto the pin-hole 1R of the right camera. The operation is the rotation required, once the pin-hole 1L of the left camera has been translated to be coincident with the pin-hole 1R of the right camera, to make the optical axis 4L of the left camera coincident with the optical axis 4R of the right camera. The operation may be represented by a 3 x 3 rotation matrix, and the operation t can be represented by a translational 3-vector.
x
p
p
p
l
x
x
l
0
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0
The epipolar geometry of a two camera set-up is illustrated in Figure 4(b). The pin-holes 1L, 1R of the left and right camera and an image point in the imaging plane 2L of the left camera define a plane . The dot-dashed lines shown in Figure 4(b) all lie in the plane . The intersection of the plane with the imaging plane 2R of the right camera defines a line known as the "epipolar line". The right image point corresponding to the left image point (this is the image point formed in the imaging plane 2R of the right camera that corresponds to the point in the object that gives rise to the image point in the imaging plane of the left camera) must lie on the epipolar line .
p
s
The rectifying transformation for the left or right image can be decomposed into two parts. The first part, denoted by H, contains the projective and similarity components of the transformation. The second part of the transformation, denoted by H, contains the horizontal shear and horizontal scaling components. The overall transformation is a combination of the projective and similarity component and the horizontal shear and scaling component. This is shown schematically in Figure 10.
At step 11 of the method of Figure 5, a stereoscopic image pair consisting of a left image and a right image pair is captured with a stereoscopic camera set-up. This step corresponds generally to step 11 of the methods of Figures 3(a) to 3(c), except that the invention requires use of a camera set-up whose statistics of intrinsic and extrinsic parameters of the camera set-up are capable of determination in some way, for example from measurements made during manufacture.
At step 12, pixel correspondences between the left and right images are detected using any standard technique, and at step 18 these correspondences are used to compute the 'Fundamental' matrix relating the two images. Steps 12 and 18 correspond generally to steps 12 and 18 of the methods of Figures 3(a) to 3(c),
At step 19, the correspondence information is used to determine a component of the rectification transformations (the "projective and similarity components") which will be used to rectify the two images. This component of the overall rectification transformations is intended to remove vertical disparity from the rectified image pair. However, this component of the rectification transformations does not necessarily result in transformations that relate to a virtual alignment to a parallel camera set-up. If the images were processed using only this component of the rectification transformations, distortion of the images could occur and the rectified image would be uncomfortable for an observer to view.
At steps 21 and 22, another component of the overall rectification transformations is determined. This component does not itself cause any change to the vertical alignment of the rectified images that would be obtained by transforming the captured image pair using just the first component of the rectification transformation. Its effect is rather to make the overall rectification transformations correspond to a virtual alignment to a parallel camera set-up.
In general, there will be more than one possible solution for the component chosen at step 22. Different possible solutions correspond to different camera parameters. Steps 21 and 22 make use of the camera statistics to select the most probable solution.
Different possible solutions to step 22 correspond to different camera parameters. Once the most probable solution to step 22 has been determined, the set of camera parameters corresponding to this solution is the most probable set of camera parameters. Thus, the most probable camera parameters are obtained from the most probable solution to step 22, and may be output to an operator at step 24.
Steps 21 and 22 in the method of Figure 5 relate to the determination of a component of the transformation that acts effectively in only the horizontal dimension, and is known as the "horizontal shear and scale" component. Shearing represents distortion of the image in the horizontal direction without having any effect on the image in the vertical direction. This could be, for example, transferring the image aspect from rectangular to trapezoidal with the same vertical dimension, although the shearing step might be more complicated than this. Horizontal scaling simply represents scaling the horizontal size of the image.
Once the projective and similarity component of the transformation, and the horizontal shear and scaling component of the transformation have been determined, they are combined at step 23, to produce the pair of rectifying transformations at step 14.
Once the rectification transformations have been determined, they may be used immediately, or they may be output and/or stored for subsequent use. When the rectification transformations are used, they are used to warp the captured image pair in a conventional manner at step 15, to produce a rectified image pair at step 16. The end product is a rectified image pair, with no, or substantially no, vertical disparity, which should be much more suitable for comfortable stereoscopic viewing than the original captured image pair.
The rectified image pair may be displayed on a suitable stereoscopic display device at step 17, for direct viewing by an observer. Alternatively, the rectified image pair can be stored for future use.
In one prior art technique, as noted above, the rectifying transformations are determined from camera parameters, such as the focal lengths and principal points of the two cameras. As also noted above, if the camera parameters used to estimate the rectification transformations are not exactly equal to the true camera parameters, the resultant rectification transformations are incorrect. This is because the horizontal shear and scaling component of the rectification transformations are determined using the camera parameters, so that use of incorrect values of the camera parameters leads to an incorrect determination of the horizontal shear and scale components of the left and right rectification transformations.
t
In the embodiment shown in Figure 5 of the application, the invention makes use of statistics of the camera parameters to ensure that the determined horizontal shear and scale components of the rectification transformations are as close as possible to the true horizontal shear and scale components. The camera statistics may include, for example, one or more of the mean and standard deviation of the focal length of the cameras, the mean and standard deviation of the principal point of the cameras, the mean and standard deviation of the rotation R between the optical axis of one camera and the optical axis of the other camera, and the mean and standard deviation of the translation between the pin-holes of the two cameras. The camera statistics may be collected, for example, during the manufacture of the individual cameras and their assembly into stereo camera set-ups. The camera statistics are input at step 20.
Each possible pair of rectification transformation will correspond to some particular values of the camera parameters. Thus, by assigning probabilities to the camera parameters, probabilities are also assigned to each possible pair of rectification transformations. Step 21 of the method of Figure 5 attempts to find the pair of rectification transformations that is most probable in view of the statistics of the camera parameters. This can be done by, for example, using the mean values of the camera parameters as a starting point, and iteratively changing the values of the camera parameters to find the most probable set of camera parameters. Once the most probable set of camera parameters has been found, the horizontal shear and scale components of the pair of rectifying transformations corresponding to this most probable set of camera parameters is determined at step 22. At step 23, the horizontal shear and scale components determined at step 22 are combined with the projective and similarity components determined at step 19, to produce the pair of rectifying transformations corresponding to the most probable set of camera parameters.
The camera parameters being estimated are the intrinsic and extrinsic parameters for the two-camera set up which captured the pair of images, and depend on data gathered from those images. Each camera parameter will have a variation around the measured mean; the variation is unknown, and the present invention enables the variation to be accounted for. Knowing the statistics of the camera parameters makes it possible to choose the most probable combination of the parameters - that is, to choose the combination of parameters which best match the actual cameras used.
R
R
As an example, it might be that the camera statistics collected during manufacture of a particular type of stereo camera show that the rotation is unlikely to have a magnitude of more than 45°. In this case, any rectifying transformations that related to camera parameters involving a rotation > 45° would be unlikely to be chosen.
One possible algorithm for performing the method of Figure 5 is described in detail below with reference to equations (1) to (27). In this algorithm, step 21 of Figure 5 is performed by minimising equation (25).
Figure 6 shows a second embodiment of the present invention. The method of Figure 6 corresponds generally to the method of Figure 5, except that some of the camera parameters are assumed to be known precisely in the method of Figure 6 and the statistical estimation stage is not required in respect of these camera parameters.
Steps 11, 12, 14-19, 22 and 23 are the same as for the method of Figure 5, and will not be discussed further.
R
t
In this embodiment of the invention it is assumed that the focal length and principal points of the left and right cameras are known, for example from tests made during manufacture, and these are input at step 25. At step 26, the rotation and translation operators and are estimated from the focal length and principal points of the cameras, and from the projective and similarity components of the transformations. This is done by decomposing the final matrix to be calculated into several parts, most of which are known. Standard mathematical methods are then used to solve for the unknown quantities.
Once the rotation and translation operators have been estimated, the horizontal shear and scaling components of the rectification transformation are determined from the known focal lengths and principal points of the cameras, and from the estimated rotation and translation operations, at step 22. The pair of rectification transformations are then found by combining the projective and similarity component of the transformations with the horizontal shear and scale components.
If desired, the estimated camera rotation and translation operations can be output at step 27.
This embodiment of the invention is particularly suited for processing a stereo image pair captured using a stereo camera set-up where the intrinsic camera parameters are accurately known, but the extrinsic parameters are not accurately known - that is, where each camera is individually of high quality, and the deviation of the stereoscopic camera set-up from a parallel camera set-up occurs primarily in the orientation of one camera relative to the other.
In the embodiments of the invention described in Figures 5 and 6, the choice of the horizontal shear and scaling components of the transformations is constrained to ensure that the resultant pair of rectifying transformations corresponds to a virtual alignment to a parallel camera set-up. To ensure this the shear component is calculated from an equation formulated such that the final matrix is a combination of a rotation and a translation and the internal camera parameters. The rotation and translation ensure that the solution corresponds to a virtual alignment to a parallel camera set-up, in contrast to prior art methods.
Figure 7 shows a further embodiment of the present invention. This embodiment corresponds to the embodiment of Figure 5, but is intended for use with a stereoscopic video input captured by a stereoscopic video recording system, such as a stereoscopic video camera. In contrast, the method of Figure 5 is intended for use with a stereoscopic image capture device that produces a pair of "still" stereoscopic images.
In the method of Figure 7, a stereoscopic video source produces a stereoscopic video picture, which may be considered as a sequence of frames where each frame contains one stereoscopic image pair. The image pair of each frame is rectified to remove vertical disparity, by warping the image at step 15. The step of warping the images at step 15 is carried out in real time, so that the rectified stereoscopic video image is displayed at the same rate as it is produced by the video source. The rectification of each image pair is carried out in the manner described above with reference to Figure 5.
The method of Figure 7 can be carried out in essentially three ways. In one approach, the image pair of the first frame captured by the stereoscopic video source is processed in the manner described above with reference to Figure 5 to determine the rectifying transformations. Once the rectifying transformations have been determined for the image pair of the first frame, they are then used to rectify the image pairs of all subsequent frames without further calculation. That is to say, steps 12 and 18-23 would not be carried out for the image pairs of the second and subsequent frames; instead, the image pairs of the second and subsequent frames would be operated on at step 15 with the pair of rectifying transformations determined for the image pair of the first frame.
A method in which the rectifying transformations are determined for the image pair of the first frame, and are not subsequently recalculated, has the advantage that it reduces the processing power required to display the stereoscopic video image. It does, however, have the potential disadvantage that, if the rectifying transformations determined from the image pair of the first frame should be incorrect, then all subsequent image pairs in the video image will be processed incorrectly.
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th
th
In another embodiment of the method of Figure 7, therefore, the rectifying transformations are re-calculated after a number of frames have been processed. In principle the rectifying transformations could be re-calculated be at irregular intervals (that is, after an irregular number of frames had been processed), but in a preferred embodiment the re-calculation is carried out at regular intervals. For example, the rectifying transformations could be re-determined after the image pairs of every N frames have been rectified. That is to say, the image pair of the first frame would be processed as described with reference to Figure 5 to determine a pair of rectifying transformations, and these rectifying transformations would be used to correct the image pairs of the 1 to N frames. The rectifying transformations would then be recalculated for the image pair of the (N+1) frame, and this re-calculated pair of rectifying transformations would be used to rectify the image pairs of the (N+1) to (2N) frames, and so on.
In the third embodiment of the method of Figure 7, the rectifying transformations are recalculated for the image pair of every frame. The rectifying transformations applied at step 15 would be updated every frame. This provides the most accurate rectification, since an error in determining a pair of rectifying transformations for a frame will affect only that frame, but requires the greatest processing power.
The flow diagram shown in Figure 7 includes a schematic switch 29, which enables any one of the three embodiments described above to be selected. For the first embodiment, the switch 29 would initially be closed, so that the first stereoscopic image pair recorded by the stereoscopic video source 28 would be subjected to the full rectification processing via steps 11, 12 and 18-23. The switch 29 would then be opened so that the second and subsequent stereoscopic image pairs captured by the video source 28 were passed directly to step 15, where they would be operated on by the rectifying transformations determined from the first image pair.
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th
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In the second method described above, the switch 29 is initially closed so that the first stereoscopic image pair recorded by the stereoscopic video source 28 is subjected to the full rectification processing via steps 11, 12 and 18-23. The 1 image pair is then processed using the rectifying transformations determined from the 1 image pair. The switch 29 is then opened, and the 2 to N image pairs are processed using the rectifying transformations determined for the 1 image pair. The switch is then closed to allow the rectifying transformations to be re-calculated for the (N+1) image pair, and the (N+1) image pair is processed using the rectifying transformations determined from the (N+1) image pair., and the switch is then opened so that the (N+2) to (2N) image pairs are processed using the rectifying transformations determined for the (N+1) image pair, and so on. (If it were desired to re-calculate the rectifying transformations after an irregular number of frames, then the switch would be opened to allow the rectifying transformations to be re-calculated after an irregular number of frames had been processed rather than after every N frames had been processed.)
Finally, in the third method described above, in which the rectifying transformations are re-calculated for every frame, the switch 29 would be kept closed.
Figure 8 shows a further embodiment of the present invention. This method is intended for use with a still stereoscopic image recording device.
Steps 11, 12 and 14 - 24 of the method of Figure 8 correspond to those of the method of Figure 5, and will not be described further. The method of Figure 8 has the added feature, compared to the method of Figure 5, that a user is provided with interactive control over the statistics of the camera parameters that are used in the determination of the rectifying transformations. In the method of Figure 8, a user is able to select or modify, at step 30, the statistics of the camera parameters.
The interactive control over the camera parameters allows the user to superimpose their knowledge about one or more camera parameters on the statistics of the camera parameters used at step 20. The user control over the camera parameters can be implemented by, for example, changing the variance of one or more camera parameters from the initial input variance of the parameters. For example, a user who has a strong belief that the relative rotation between the optical axes of the two cameras of the stereoscopic camera set up is small would be able to decrease the variance relating to the rotation, to further reduce the possibility that the selected rectifying transformations will correspond to a large rotation.
In a modified version of the embodiment of Figure 8, it is possible for an appropriately sub-sampled portion of the rectified image to be displayed in real-time. For example, sub-sampled portions of the left and right images could be rectified using an initial pair of rectification transformations and the results displayed. If the displayed results indicated that the initial rectification transformations were satisfactory at eliminating vertical disparity, the initial rectification transformations could be adopted. However, if the displayed results indicated that the initial rectification transformations did not satisfactorily eliminate vertical disparity, the user could vary one or more of the camera parameters thereby to alter the rectification transformations, the new rectification transformations could be used to rectify the sub-sampled portion, and the new results displayed; these steps could be repeated until satisfactory rectifying transformations were obtained. This embodiment allows user to monitor the effect of adjusting the camera parameters and obtain feedback to what the final image might look like. The maximum size of the sub-sampled image that can be displayed this way will depend on the available processing power.
Figure 9 illustrates a further embodiment of the invention. The embodiment of Figure 9 corresponds generally to that of Figure 8 in that it provides interactive control over the camera parameters, but it is for use with a stereoscopic video source rather than a still stereoscopic image source. The steps of the embodiment of Figure 9 correspond generally to steps in the embodiments of Figure 7 or Figure 8, and so will not be described in detail.
A further embodiment of the present invention (not illustrated) corresponds generally to the embodiment of Figure 6, but is adapted for use with a stereoscopic video source rather than a still stereoscopic camera.
An algorithm suitable for performing the method shown in Figure 5 will now be described in detail.
The camera model is the set-up of two pin-hole cameras shown in Fig. 3(a). It is assumed that lens distortions are negligible or are accounted for by pre-processing the images. The origin of the world co-ordinates is chosen to be the pin-hole of the first camera. The origin of the image co-ordinates is the centre of the image. Vectors and matrices are projective quantities, unless stated otherwise. Equality of projective quantities denotes equality up to scale.
P
X
x
x
= P
X
x
x
i
i
i
i
i
i
th
A 3 x 4 (3 row x 4 column) camera matrix takes a three-dimensional point and projects it to a two-dimensional image point i.e. . X is a 3-dimensional point, but its matrix representation has a 4 co-ordinate as typically used in matrix transformations, especially perspective transforms. The matrix representation of has three co-ordinates, and can be thought of as a scaled two-dimensional co-ordinate with the 3rd co-ordinate equal to 1 - a typical perspective transform result.
P
0
K
0
P
1
K
1
=
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=
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T
R
T
K
i
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i
R
R
t
i =
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i
i
i
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The camera matrices are given by where is the 3 × 3 calibration matrix of the th camera ( = 0 for the left camera and = 1 for the right camera), is a 3 × 3 rotation matrix and t is a translation 3-vector. and are respectively the rotation and translation of the right camera ( 1) relative to the left camera ( = 0) in Fig. 3(a). Assuming that skew is negligible, the calibration matrix is where is the effective focal length and () is the principal point in the image plane.
F
F
x
x
j
t
oj
ij
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i
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= 0
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=
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0
-1
The 3 × 3 fundamental matrix relates to the projective and similarity components of the rectifying transformation, as indicated by step 18 of Figures 5 to 9. The fundamental matrix relates to a point in the left image of an image pair to the corresponding point in the right image of the image pair. for all . The fundamental matrix encapsulates the epipolar geometry of a two-camera setup, and is given by where []x denotes the anti-symmetric matrix
x
0
The epipolar geometry of two cameras is illustrated in Fig. 4(b). As noted above, the right image point corresponding to left image point must lie on the epipolar line, and this is expressed algebraically by Eq. 3.
H
, H
0
1
oj
1
j
x
¯
x
¯
x
¯
oj
H
o
x
oj
x
¯
ij
H
1
x
1
j
=
and
=
It is required to find a pair of rectifying homographies () such that the transformed corresponding image points { ↔ }, which are given by satisfy
y
i
F
[
i
]×
,
= H
1
T
H
0
T
Note that Eq. 7 is an epipolar constraint with a fundamental matrix which corresponds to identical cameras with only a translation between the cameras. Matching epipolar lines in the transformed images will be horizontal and have the same offset. The constraint on the rectifying homographies is thus where = [1, 0, 0]
Step 12 in the methods of Figs. 5 to 9, labelled "correspondence detection", establishes pairs of image points (one point in the left image and one point in the right image) which are images of a unique three-dimensional point in the object scene. The inputs to step 12 are an image pair and optionally the statistics of the camera parameters. The output is a fundamental matrix.
The correspondence of the point features is established using known robust statistical methods like RANSAC as disclosed by, for example, M. Fischler et al in "Random sample consensus: A paradigm for model fitting with applications to image analysis and automated cartography" in "Communications of the ACM" Vol 24, No. 6, pp381-395 (1981) or by P. Torr et al in "Outlier detection and motion segmentation" in "SPIE Sensor Fusion VI" Vol 2059 pp 432-443 (1993), or Least Median Square as disclosed by R. Deriche et al in "Robust recovery of the epipolar geometry for an uncalibrated stereo rig" in "European Conference on Computer Vision" pp567-576 (1994). Robust methods will reject chance correspondences which do not fit into the epipolar geometry governed by the majority of the correspondences.
F
x
x
x
Fx
0j
ij
oj
T
1
j
In the search of correspondences, the statistics of the camera parameters are used to restrict the search. In the case where the camera parameters are known exactly, the exact fundamental matrix is given by Eq. 4. A point feature in the left image (image 0) must correspond to a point feature in the right image (image 1) which lies on the epipolar line = 0. When the camera parameters are not known exactly, instead of just searching along the epipolar line, the correspondence search is widened to a region around the epipolar line. The better accuracy the camera calibration is known, the more restricted is the correspondence search.
Box 20 in Figs. 5 to 9, labelled "statistics of camera parameters", consists of results of some calibration procedure which establishes the variations of the intrinsic and extrinsic camera parameters. For example, the mean and variance of the parameters may be determined. A typical calibration procedure involves recording different views of a known calibration object. Examples of known methods are disclosed by R. Tsai in "An efficient and accurate camera calibration technique for 3D machine vision" in "Conference on Computer Vision and Pattern Recognition" pp364-374 (1986) and by Z Zhang in "Flexible camera calibration by viewing a plane from unknown orientations" in "International Conference on Computer Vision" (1999). Both of these methods account for lens distortions. There are also calibration methods known as "self-calibration" which do not use a calibration object and depend on features in a scene. Examples are disclosed by R. Hartley in "Self-Calibration from multiple views with a rotating camera" in "European Conference on Computer Vision" pp 471-478, Springer-Verlag (1994) and by A. Zisserman et al in "Metric calibration of a stereo rig" IEEE Workshop on Representation of Visual Scenes, Boston, pp93-100 (1995).
H
H
H = H
H
H
where
H
HH
H
0
1
s
r
p
s
-1
P
-1
r
Loop et al (supra) have provided a useful decomposition and relationship of the rectifying homographies and A projective matrix can be decomposed into and = is of the following form
H
H
H
H
p
r
s
s
The matrix contains only projective terms. The matrix is a similarity transformation, with the upper-left 2 x 2 sub-matrix being an orthogonal matrix (scale + rotation). The matrix is a horizontal scale and shear transform. For brevity, we will call the shear component.
H
i
H
, H
H
H
H
i
is
ir
ip
0
1
Let the rectifying homography for camera be decomposed into and . Since and are rectifying homographies satisfying Eq. 8, there are certain relationships between the decomposed matrices, as discussed below.
Step 19 of the method of Figs 5 to 9, labelled "estimate projective and similarity component", will now be considered.
e
e
F.
x
H
i
i
ip
T
Let and denote the epipoles of the original and rectified image pair respectively. the epipoles are readily calculated from the fundamental matrix For a pair of rectified images, the epipoles are at infinity and lie on the -axis. i.e. = [1,0,0]. Since only the projective terms in can map finite points to infinity, information about the projective terms are contained in the epipoles. The following describes a procedure to determine the projective terms from the epipoles.
e
x
x
x
0
The similarity and projective components for image 0 is determined by first rotating the epipole onto the -axis and then mapping it to infinity by the projective components. There are two rotations which map an epipole onto the -axis (that is, onto the positive and negative side of the -axis). The rotation with the smallest angle is chosen, and is denoted by
0
0r
0
0p
0
= H
e
rotated
e(i)
i
e
H'
Let the rotated epipole be e'. We set the projective component in the co-ordinate frame as where denotes the th component of the vector . will map the rotated epipole e' to infinity. It is assumed for the moment that = 0.
w
s
w
s
c
0a
0z
0
z
0
b
0
z
0
z
The projective component in the original co-ordinate frame is thus i.e. =c - and = + .
H
, H
F,
H
, H
H
i
H
=
i
x
0r
op
1r
1p
0
s
is
T
1
s
F = H
1
T
H
1
T
p
r
H
0
r
H
op
[
i
]×
.
The problem now is: given () and the fundamental matrix to find the matching rectifying homographies (). The rectification constraint on the homographies is given in Eq. 8. Since []× [], the shear components H do not affect the rectification. Eq. 8 only constrains the similarity and projective components i.e.
H
H
H
H
s
w
c
w
or
op
1r
1p
0
z
0
a
0
z
0
b
H
1
T
H
1
r
T
= FH
0
p
-1
H
0
r
-1
[
i
]
x
Given (, ), it is possible to solve for (, ) using Eq. 15. In particular, if then where = - + . Solving the above equations and noting that equality is up to scale, yields the following solution. where
M (i,j)
i,j
M.
H
H
e
e
x
c
s
c
s
H
or
1r
0
1
1r
2
0
z
2
0
z
2
1
z
2
1
z
denotes the ()th element of the matrix It can be verified that the rotation matrices in and correspond to the rotation of the epipoles and onto the -axis. Note that + = 1, but + is not necessarily unity; there is a scale factor in the similarity transform .
In the above procedure, the projective term of image 0 was arbitrarily set to zero in Eq. 13. This leads to a certain value for the projective term in the right image (image 1). In fact there is a one-parameter family of choices for the pair (, ), each of which leads to a pair of homographies that satisfy the rectification constraint in Eq. 8. The freedom in the choice of the projective term is related to the freedom in the choice of the rotation about the baseline of a pair of parallel cameras. All rotations about the baseline of a pair of parallel cameras will give a pair of rectified images.
y
H
s
w
+ c
w
w
w
ir
iz
ia
iz
ib
1a
1b
To minimise the amount of image distortion, one can choose such that = - R. Hartley (1998) (supra) and Loop et al (supra) used image distortion criteria that are different from the one disclosed here. Noting that denotes the -component projective term in the co-ordinate frame rotated by (i.e. = -), it is necessary to solve: With and given by Eq. 19 in terms of , this leads to a quadratic equation with
This may be solved using the standard formula for the roots of a quadratic equation; the solution with the smaller magnitude is chosen.
Figure 6 illustrates a method in which the camera calibration is known. Step 26 of Figure 6, labelled "estimate rotation & translation" in Figure 6, will now be considered.
Since Eq. 7 does not impose any constraints on the shear component, we have complete freedom in choosing the 6 (3 per image) horizontal shear/scale parameters. These terms are typically chosen by minimising some image distortion criterion. The criterion used by R. Hartley (1998) (supra) relates to disparity ranges in the rectified images. The criterion used in by Loop et al (supra) relates to the aspect ratio and perpendicularity of two lines formed by the midpoints of the image boundary. The output of the rectification in these prior methods is used for disparity estimation.
The criteria used to determine the shear component in these prior art methods can lead to rectification transformations that do not correspond to a virtual alignment to a parallel camera set-up. This is because these prior art methods do not relate to the display of a stereoscopic image. As long as the shear terms do not result in a significant distortion, a disparity estimator will be able to correlate features between the images. For the purpose of viewing the rectified image pair on a stereoscopic display, however, there is a more stringent requirement.
a priori
a priori
According to the method of Figure 6, the criterion for the determination of the shear component relates to what is physically probable. The shear component is chosen such that the rectifying homography corresponds to virtually rotating the camera. Furthermore, the shear terms are constrained using knowledge of the intrinsic and extrinsic parameters of the camera. This knowledge is expressed in terms of probability densities. All parameters are assumed to follow a Gaussian (or truncated Gaussian) distribution with a certain mean and variance.
K
R
K
R
K
i
R
R
R
R
t
H
H
i
i
i
i
i
i
o
1
is
it
-1
H
it
H
is
H
ir
H
ip
= R
i
K
i
-1
Assume for the moment that the calibration matrices are known. For some rotation matrix , is the homography which virtually rotates camera by . For a pair of rectifying homographies, and are functions of the camera rotation and translation . The shear component must satisfy for some scale and translation transform of the form
H
, H
, K
U
H
H
R
ir
ip
i
i
it
is
i
U
i
H
ir
H
ip
K
i
= (U
i
H
or
H
ip
K
i
U
i
)
-T
U
i
T
= H
ir
-T
H
ip
-T
K
i
-T
K
i
-1
H
ip
-1
H
ir
-1
Given (), an upper triangular matrix = is required such that Eq. 22 is satisfied. Because is an orthonormal matrix, we have
U
H
R
R
R
t
i
is
0
1
Cholesky decomposition of the right hand side of Eqn. 24 gives , and hence the shear component . This also gives the rotations and , from which the camera rotation and translation can be calculated.
R
t
K
K
i
i
The convention thus provides a procedure for estimating and from known calibration matrices and the projective and similarity components. Since only the horizontal shear and scale components is affected by the calibration matrices inaccuracies in the calibration matrices will only lead to an incorrect horizontal shear and scale in the final rectifying homography. Zero vertical disparity is maintained in spite of inaccurate camera calibrations. This is illustrated in Figure 6, where errors in the "camera focal lengths & principal points" box, box 25, are only propagated to the "horizontal shear & scale component" box. The methods of Ayache et al, Kang et al and Fusiello et al do not have this error-tolerant property.
Step 21 of the method of Figs. 5 to 9, labelled "find most probable focal lengths, principal points, rotation & translation" will now be considered. In the method of Figure 6, the calibration matrices are assumed to be known. The matrices will in fact not be known exactly. The parameters are only known up to a certain accuracy that is specified by the mean and variance of a Gaussian distribution. In the method of Figure 5, the procedure in the dashed-box in Figure 6 is modified to account for this.
x
K
, K
, R, t
x
x
0
1
Let the mean and standard deviation of a parameter by denoted by µ and σ respectively. We seek the parameters () which minimise a weighted sum of the squares of errors from the mean, i.e.
θ
R, t
R
t.
R
t
j
The solution to Eq. 25 is the most probable set of parameters. The five functions () are simply functions to extract the angles of rotations from the rotation matrix and translation vector There are 5 angles because there are 3 angles for , and 2 angles for the direction of the translation .
For simplicity, functions that account for truncation in Eq. 25 i.e. focal length must be positive, principal point must be within image and angles must be within ± 180° have been omitted. These constraints are implemented in practice.
In the embodiments of Figures 8 and 9 a user is able to vary one or more of the quantities in Eqn. 25, so that the user has control over the camera parameters.
R
t
The non-linear objective function in Eq. 25 can be minimised by any suitable mathematical technique. One suitable technique for minimising Eq 25 is the Levenberg-Marquardt method. The initial input to the iterative Levenberg-Marquardt algorithm is the camera rotation and translation estimated using the mean calibration matrices with the procedure in the previous section.
H
= H
H
H
H
H
H
H
A
Ã
i
i
i
H
H
i
is
ir
ip
0
1
0
1
i
i
i
i
i
τ=
2
A
0
Ã
0
/
+
A
1
Ã
1
/
T
The rectifying homographies are given by . The final step applies (i) a scale to both homographies and such that the area of the image is roughly preserved after rectification, and (ii) a translation to both homographies and such that the rectified image is roughly central. Let and be the areas of the original image and the rectified image respectively. The mean scale is used to roughly preserve the areas of both rectified images. Instead of the arithmetic mean, the geometric mean can alternatively be used. The central point in image is mapped to [(0,2),H(1,2),1]. Preferably a translation such that the central point is mapped to the mean of the two rectified central image point is used. The scale and translation matrix applied to both is:
e
e
F.
0
1
1. Calculate the epipoles and from the estimated
e
x
0
T
2. Rotate the first image such that the epipolar lies on the -axis. Find the projective terms such that the rotated epipole is mapped to infinity [1, 0, 0].
3. From the similarity and projective components for the first image, find the corresponding similarity and projective homographies for the second image according to Eqns. 18 and 19.
w
w
0b
1b
4. Re-choose the projective terms and to minimise image distortion.
a priori
5. Choose the shear terms according to Eqn 25 which is based on knowledge of the camera parameters.
H
= H
H
H
H
, H
H
i
is
ir
ip.
is
ir
ip
6. Form the resultant rectifying homographies with where and are the shear, similarity and projective components respectively.
H
H
H
H
0
1
0
1
7. Apply a scale to both homographies and such that the area of the image is roughly preserved. Apply a translation to both homographies and such that the rectified image is roughly central.
The principal features of an algorithm suitable for implementing the method of Figure 5 may be summarised as follows.
Algorithms for other embodiments of the invention may be obtained by making appropriate modifications to the above-described routine.
In the methods described in the application, the two components of the rectification transformations are determined, and these are then combined. The images are then rectified by warping the images using the combined transformations. In principle it would be possible for the step of combining the two components of the transformations to be eliminated, and for the warping step to have two stages (namely, a first warping step using the first component of the rectification transformations followed by a second warping step using the second component).
Figure 11 is a schematic block diagram of an apparatus 31 that is able to perform a method according to the present invention. The apparatus is able to a stereoscopic image pair according to any method described hereinabove so as to obtain a pair of rectifying transformations. The apparatus may further process one or more image pairs using the obtained rectifying transformations.
The apparatus 31 comprises a programmable data processor 32 with a program memory 33, for instance in the form of a read only memory (ROM), storing a program for controlling the data processor 32 to process acoustic data by a method of the invention. The apparatus further comprises non-volatile read/write memory 34 for storing, for example, any data which must be retained in the absence of a power supply. A "working" or "scratch pad" memory for the data processor is provided by a random access memory RAM 35. An input device 36 is provided, for instance for receiving user commands and data. An output device 37 is provided, for instance, for displaying information relating to the progress and result of the processing. The output device may be, for example, a printer, a visual display unit, or an output memory.
Image pairs for processing may be supplied via the input device 36 or may optionally be provided by a machine-readable store 38.
The determined rectifying transformations may be output via the output device 37, or may be stored. Alternatively, once a pair of rectifying transformations have been determined the apparatus may process one or more image pairs using the rectifying transformations. The rectified image pairs may be output, for example for display, via the output device 37 or may be stored.
The program for operating the system and for performing the method described hereinbefore is stored in the program memory 33, which may be embodied as a semiconductor memory, for instance of the well known ROM type. However, the program may well be stored in any other suitable storage medium, such as a magnetic data carrier 33a (such as a "floppy disc") or a CD-ROM 33b. | |
Set of Designs for Friezes
- Object:
- Place of origin:
London
London (made)
- Date:
1640 (first published)
1668 (published)
- Artist/Maker:
Pearce, Edward (designer)
- Materials and Techniques:
engraving
- Museum number:
E.3618-1907
- Gallery location:
Prints & Drawings Study Room, level D, case EO, shelf 91
Edward Pearce, the designer of this series, was one of the leading British artists of the Baroque style in his day. As a contemporary and associate of Inigo Jones, he worked particularly on interior decoration. This series of frieze designs reflect Pearce’s taste. Originally published in 1640, this edition is a posthumous reproduction from 1668, ten years after the artist’s death. Like Jones, Pearce believed that buildings should be constructed with strong, masculine exteriors and rich, elaborate interiors. This mix of architectural and florid design is evident throughout the frieze series. Putti drape themselves across bundles of fruit alongside solid architectural frames. During Pearce’s career, Richard Symonds praised him for having the best grasp on perspective of any British artist of the day. This too is evident in the series, and through attentive shading and positioning of various decorative elements, Pearce creates a sense of depth, even in a limited space.
Physical description
Design for frieze showing on the left an eagle rampant and, running across the centre, a swag beneath a mask. On the right a female figure holds a bowl of fruit and leans against and architectural frame topped with another mask.
Place of Origin
London
London (made)
Date
1640 (first published)
1668 (published)
Artist/maker
Pearce, Edward (designer)
Materials and Techniques
engraving
Marks and inscriptions
"5"
Dimensions
Height: 10 cm, Width: 28.6 cm
Object history note
One of Pearce’s most famous endeavours was the decoration of the Double Cube Room at Wilton House, which he completed working under Inigo Jones with John Webb. In fact, work by Dr. Gordon Higgott of English Heritage suggests that many of the drawings for the House originally attributed to Jones were actually Pearce’s work (2012). These drawings and images of the room give an idea how the design elements in Pearce’s frieze were implemented as three-dimensional decoration.
Descriptive line
Edward Pearce (after), plate from suite of twelve, including title plate showing designs for friezes. British, 1640.
Bibliographic References (Citation, Note/Abstract, NAL no)
Kunstbibliothek (Berlin, Germany). Katalog der Ornamentstichsammlung der Staatlichen Kunstbibliothek, Berlin. New York: B. Franklin, 1958.
Croft-Murray, Edward. Decorative painting in England 1, Early Tudor to Sir James Thornhill. London: Country, 1962. | http://collections.vam.ac.uk/item/O1043328/set-of-designs-for-friezes-print-pearce-edward/?print=1 |
The utility model discloses a multifunctional combined earring. The multifunctional combined earring comprises an ear stud and an ear line, the ear line is divided into a long section and a short section through the annular hasp, and various wearing models are realized through the annular hasp. According to the utility model, through combined use, the wearing function diversity is realized, and the wearing effects of simplicity, elegance, flexibility and gracefulness are achieved. | |
58-41-35. Contents required in evidence of coverage.
An evidence of coverage shall contain a clear, concise, and complete statement of:
(1) The health care services and the insurance or other benefits, if any, to which the enrollee is entitled under the health care plan;
(2) Any exclusions or limitations on the services, kind of services, benefits, or kind of benefits, to be provided, including any deductible or copayment feature;
(3) Where and in what manner information is available as to how service, including emergency and out-of-area services, may be obtained;
(4) The total amount of payment and copayment if any, for health care services and the indemnity or service benefits, if any, which the enrollee is obligated to pay with respect to individual contracts, or an indication whether the plan is contributory or noncontributory with respect to group certificates; and
(5) A description of the health maintenance organization's method for resolving enrollee complaints.
Source: SL 1974, ch 321, § 19 (2). | https://sdlegislature.gov/api/Statutes/2077157.html |
President Andres Manuel Lopez Obrador yesterday inaugurated Who’s Who in the Lies of the Week, which will be broadcast every Wednesday as his government’s response mechanism for displaying “fake news” that is exposed in the media and social networks. He informed the Chair that the response would be accepted, and expressed his expectation that this space would contribute to enriching public life through debate. For her part, Ana Elizabeth García Velches, who is responsible for presenting this segment and who “will be nominated as Director of Public Coordination Networks for Social Communication and Spokesperson for the Presidency”, declared that the goal is to “communicate the truth so that the people of Mexico can exercise their right of access to information “for” Configure a standard with certainty.”
The passage begins with exercises to “verify” statements of government officials made by various media in Mexico and other countries, but reflects the terms of the equation: in this case, it is the public authority that examines and presents inaccuracies or inconsistencies emanating from private platforms. This investment is controversial and has been the target of multiple criticisms for its alleged “truth hoarding” or “indiscriminate killing”, but it seems a good idea to offer citizens the possibility to have different perspectives to assess and shape their own criteria for government action.
The truth is that there is a socio-political moment in which the ways of the media often misunderstand the boundaries between data and opinion, between rumor and facts, and thus lead to the systematic construction of fallacies that distort reality. Because of the lack of care in dealing with information, hoaxes manufactured in social networks jump without a journalist’s presentation of television newscasts, radio programs or print media; Otherwise, they go in the opposite direction: the method of supposed seriousness lends credence to false news that subsequently spreads in the hypothetical realm.
In this context, the latest extraordinary gesture of a government that is characterized by adopting measures and approaches unprecedented in previous governments is taking place. This should come as no surprise given that the so-called Fourth Shift came to power precisely with a promise to distance itself from previous administrations’ red tape.
Not because it is so unusual, the exercise which is no longer of value, without imposing any form of censorship or affecting anyone’s freedom of expression, brings into the field of public debate ways of recounting national events that undoubtedly deviated from reality. In this sense, it should seem healthy to all concerned that in the context of democracy and liberties, the space for discussion on issues of national interest should be expanded and expanded. | https://www.smallcapnews.co.uk/la-jornada-infodemia-an-unprecedented-workout/ |
This is an individual assignment Work and solve Case 16.2 Bond Investment Strategy, (pages 835 & 836 in Business Analytics Data Analysis and Decision Making, 7th Edition). This assignment is worth 35 points. You will need at least 2 hours to complete this assignment.
Requirements:
Submission must include one excel spreadsheet with all appropriate work and one word/pdf report (one submission per group).
first two questions have at lease one word one excel each. | https://masterswriters.com/2022/02/11/solve-case-16-2-bond-investment-strategy/ |
The incumbent is expected to perform the duties Living the Unifrax Values of Safety, Ethics, People, Commitment, Customer Focus, Innovation, Continuous Improvement, Teamwork, Speed and Agility.
Continuous monitoring of various operating equipment to meet daily key performance indicators (KPI’s) for Safety, Quality and Production Rate.
Responsible for following written work instructions to set-up, operate and control process related equipment to safely manufacture ceramic fibers and products
Follow written work instructions and perform tasks for chemical solution batching, adjustments during processing and transferring batches between various process tanks
Complete record sheets during process chemical batching
Monitor equipment and conduct minor repairs as required
Perform quality checks per QA work instruction as desired for operations
Perform material handling tasks as needed including finished goods packaging, shipping/receiving, raw material storage and maintain orderly racking of materials.
Complete minor mechanical adjustments to support manufacturing
Changing, disassembling, assembling and cleaning equipment as required
Troubleshoots equipment, process and quality issues to assist maintenance and engineering staff in resolving issues
Works well indivisibly and in group settings with all levels of plant staff
Maintains clean, safe, orderly workplace (5S and Six Sigma knowledge desired)
Must visually inspect the finished product
Must roll, label, wrap and complete written paperwork of the product per written work instructions
Responsible for training operators per work instruction in accordance with Unifrax policies
Provide relief for other areas of production
Perform other duties as assigned
Qualifications:
High School Diploma or equivalent required, Associate degree or other post high school training preferred (Prior chemical operator experience desirable)
The Line Operator must have a working knowledge of Microsoft office, along with basic computer skills are required
Be able to learn and access information through computer databases
Be able to read and interpret simple gauges
Follow work instructions and provide feedback for improvements
The individual must also be able to work a 12-hour, continuous shift schedule (4 days on, 4 days off from 7-7 rotating days/nights)
Be able to lift up to 50 lbs.
Be able to bend, stoop, lift, squat, walk, and stand for up to 12 hours at a time.
Tools and equipment used: Fork truck, computer, wet scrubber, furnaces, small hand tools, tape gun, stretch wrapper, power washer, etc.
Other Duties / Quantitative Dimensions:
Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time or without notice.
At Unifrax, we provide innovative solutions to our customers' application problems across several different industries. Our engineers work with a team of research and development specialists to create high performance specialty fibers and inorganic materials used in high-temperature industrial, automotive and fire protection applications designed with the ultimate goal of saving energy, reducing pollution, and improving fire safety for people, buildings and equipment. Since 1942, Unifrax products and materials have been providing solutions to our Distributors and customers to solve their application challenges. Our products are known universally for their quality and proven performance with names like Fiberfrax® ceramic fiber products, revolutionary low bio-persistent Insulfrax® and Isofrax® alkaline earth silicate fiber products, PC-Max® and Ecoflex® Support Mats for emission control products, FyreWrap® Fire Protection Systems, and Specialty Glass microfibers products used in high efficiency filtration media by nonwovens producers. | https://nyhirenow.usnlx.com/buffalo-ny/line-operator/17685B3AEE2C486788CC54E7C6AE7FF3/job/ |
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