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http://fmoldove.blogspot.com/2013/06/quantum-mechanics-and-unitarity-part-4.html | Quantum mechanics and unitarity (part 4 of 4)
Now we can put the whole thing together and attempt to solve the measurement problem. But is there a problem to begin with? Here is a description of the problem as written by Roderich Tumulka http://www.math.rutgers.edu/~tumulka/teaching/fall11/325/script2.pdf (see page 53):
• In each run of the experiment, there is a unique outcome.
• The wave function is a complete description of a system’s physical state.
• The evolution of the wave function of an isolated system is always given by the
Schrödinger equation
Then in the standard formulation of quantum mechanics at least one of them has to be refuted. From the quantum mechanics reconstruction work, the last two bullets are iron-clad and cannot be violated without collapsing the entire theory. This means that GRW theory, and Bohmian interpretations are automatically excluded. Also the usual Copenhagen interpretation is not viable either because it makes use of classical physics (we know that we cannot have a consistent theory of classical and quantum mechanics). Epistemic approaches in the spirit of Peres are not the whole story either because while collapse is naturally understood as information update, this means that Leibniz identity is violated as well.
So what do we have left? Only the many-worlds interpretation (MWI), or its more modern form of Zurek’s relative state interpretation http://arxiv.org/abs/0707.2832.
However, I will argue for another fully unitary solution different than MWI/relative state interpretation (and I agree with Zurek that the old fashion MWI gives up too soon on finding the solution), but in the same spirit of Zurek’s approach. The basic idea is that measurement is not a primitive operation. The experimental outcome creates huge numbers of information copies. The key difference between Zurek’s quantum Darwinism and the new explanation is on who succeeds in creating the information copies: the full wavefunction (as in quantum Darwinism), or the one and only experimental outcome. In other words, the Grothendieck equivalence relationship is broken by the measurement amplification effects: only one equivalent representative of the Grothendieck group element succeeds in making information copies and statistically overwhelms all the other ones (for all practical purposes). The information in the “collapsed part of the wavefunction” is not erased, but becomes undetectable.
Of course there are still open problems of delicate technical nature to be solved in this new paradigm, but they do seem to get their full answer in this framework. Solving them is a work in progress, and the solution is not yet ready for public disclosure.
In subsequent posts I’ll show how the wavefunction is neither epistemological, nor ontological and I will touch on Bell’s theorem, and the recent PBR result among other things. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8351361155509949, "perplexity": 611.1916766766698}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218189090.69/warc/CC-MAIN-20170322212949-00158-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://jcom.sissa.it/archive/18/02/JCOM_1802_2019_A02 | # Does the messenger matter? Studying the impacts of scientists and engineers interacting with public audiences at science festival events
### Abstract:
Over the past decade, science festival expos have emerged as popular opportunities for practicing scientists to engage in education outreach with public audiences. In this paper, a partial proportional odds model was used to analyze 5,498 surveys collected from attendees at 14 science expos around the United States. Respondents who report that they interacted with a scientist rated their experiences more positively than those who reported no such interaction on five categories: overall experience, learning, inspiration, fun, and awareness of STEM careers. The results indicate that scientists can positively affect audience perception of their experience at these large-scale public events.
Keywords:
28 January 2019
### 1 Introduction
Science festivals continue to grow in popularity as innovative opportunities for scientists and engineers to engage in education outreach [Bultitude, McDonald and Custead, 2011; Boyette and Young, 2014; Wiehe, 2018]. Science festivals exemplify the blend of methodologies and goals that define contemporary science engagement efforts [Holliman and Jensen, 2009]. They vary in scope, size, target audience, and mission, yet generally share one characteristic: a large-scale public exposition (expo) event that draws hundreds and possibly thousands of participants. These expos look like a typical street fair, except that exhibitors are engaging the public with STEM education experiences instead of food, music, arts, or crafts. They are a part of an “evolving culture of science engagement” [Durant and Linett, 2014] and are embraced by STEM education institutions as effective ways to promote science engagement among their audiences [Bultitude, McDonald and Custead, 2011; Boyette and Young, 2014]. These public science events are designed to engage public audiences in a meaningful social context [Durant, Buckley et al., 2016]. Exhibitors are primarily practicing scientists, engineers, STEM educators, science communication professionals, and science-based commercial vendors. This study focuses on the interactions between scientists and engineers and the general public that visits these expos.
In an effort to increase public understanding and support of STEM research and practice, science and engineering practitioners are being asked to actively engage in educational outreach and participate in “respectful dialogues between [them] and the general public” [Leshner, 2015]. Liang et al. [2014] suggest that changing socio-cultural patterns and communication environments have increased attention to practitioners’ roles in communicating their research “outside the ivory tower.” Many STEM researchers and thought leaders believe that “the burden of passing along the understandings and implications of contemporary science falls squarely on the shoulders of those actively engaged in funding, publishing and carrying out research” [Editorial, 2010]. In response, these researchers are increasingly encouraged to participate in outreach and engagement activities, broadly defined as “any scientific communication that [directly] engages an audience outside of academia” [Poliakoff and Webb, 2007]. In recent years, scientists and engineers have increasingly utilized science festivals, and particularly science expos, to participate in STEM outreach and engagement. According to the Science Festival Alliance (SFA), an organization made up of more than 50 science festivals across the United States, nearly 20,000 STEM professionals played “an active role” in SFA member festivals in 2017 [Wiehe, 2018].
#### 1.1 Scientists-public interactions
Although opportunities continue to increase for scientists and engineers to become involved in public engagement with science, little research has been conducted on the impacts of such efforts. The sparse research available does suggest positive benefits from public engagement work, especially among the scientists and engineers themselves. An assessment of the National Science Foundation’s Graduate STEM Fellows in K-12 Education found that fellows were more engaged in their research, better able to explain STEM concepts to lay audiences, more interested in STEM education and public policy, and had better time management skills than their peers [Boone and Marsteller, 2011]. In addition, experience teaching science has been shown to increase methodological research skills such as developing testable hypotheses and designing valid experiments [Feldon et al., 2011]. In general, academics involved in public engagement work publish their research more frequently than their non-engaged colleagues, and their publication rates increase with increasing public engagement activity [Jensen, Rouquier et al., 2008]. Liang et al. [2014] found that public communication activity increased scholars’ scientific impact as measured by their h-index, a metric that quantifies the cumulative impact and relevance of an individual’s research output [Hirsch, 2005].
Research is also very limited on the impacts of these kinds of interactions on public audiences, although preliminary work does suggest that the lay public’s science knowledge can be influenced by interactions with scientists and engineers [Davis and Russ, 2015]. Perceptions of scientists, in general, can also be influenced by personal interactions. Although public audiences generally hold traditional, outdated, and inaccurate ideas about what scientists and scientific activities look like, [Woods-Townsend et al., 2016; Christidou, 2010], after personal interactions with scientists, children and adults’ depictions of them are more accurate [Woods-Townsend et al., 2016].
Surveys and interviews of science festival attendees indicate that the general public benefit from interactions with scientists and engineers. In Jensen and Buckley [2014] study of interests, motivations, and self-reported benefits of public engagement with research at the Cambridge (U.K.) Science Festival, attendees identified social interaction and access to active science researchers as unique opportunities offered by science festivals that are not available with other science engagement activities. In their investigation of impacts of a panel discussion at the Wisconsin Science Festival, Rose et al. [2017] found that the panel increased audience members’ understanding of the topic discussed (human gene editing). Science festival evaluation data has also shown positive impacts on public audiences when they interact with “STEM practitioners.” In a summative evaluation of the NSF-sponsored Science Festival Alliance project, Goodman Research Group reported that events were rated more positively by survey respondents if they interacted with STEM practitioners compared to those that had not [Manning et al., 2012].
Interestingly enough, the paucity of research in this area means that the strong push for scientists and engineers to become involved in public engagement is based primarily on an assumption that such involvement is effective in increasing the lay public’s understanding and appreciation of STEM and STEM research. This current study is an attempt to fill the void in the research and knowledge base for the measured impacts on the public from scientists’ outreach and engagement activities.
### 2 Methods
#### 2.1 EvalFest attendee survey
EvalFest is an NSF-funded project involving multi-site evaluation of science festivals across the United States. As part of this project, the EvalFest team developed a survey to be completed by attendees of science expos at participating science festivals. Demographic data was collected from attendees over 14 years of age. A subset of questions on each attendee survey were considered the “core questions” and included on every survey. Each individual expo site was allowed to customize its attendee survey by selecting other questions from EvalFest’s question bank to add to the core questions. All survey questions were validated by collecting response process validity evidence through think-aloud interviews during expos with youth and adults.
#### 2.2 Audience perceptions of expo experiences
For the purposes of this study, the investigators analyzed data from the 14 EvalFest science expos that collected attendee demographic data on gender, race, home zip code, and education level at their science expo events. Two categories (male/female) were used for analysis of survey responses by gender. For analysis by race, attendees were classified as underrepresented minorities (URM) if they identified as Black, Hispanic, American Indian, or Alaska Native. Here, the term ‘underrepresented’ alludes to the inequitable representation of these racial groups in the U.S. STEM workforce [National Center for Science and Engineering Statistics, 2017]. It should be noted that respondents did not self-report their income. For analysis of this variable, income levels of respondents are inferred by the median income of their reported home zip code as documented by the U.S. Census Bureau. Median household income is reported using nine categories: less than $15,000;$15,000–$24,999;$25,000–$34,999;$35,000–$49,999;$50,000–$74,999;$75,000–$99,999;$100,000–$149,999;$150,000–$199,999; and$200,000 or more.
In addition to the demographic questions, the expo attendee surveys also ask the respondents to answer three questions evaluating their experience of the event using a five-point Likert scale (Strongly Disagree…Strongly Agree) and are asked to rate the event overall using a five-point Likert scale (Poor…Excellent). Respondents are also asked whether or not they have interacted with a scientist or engineer within the past year, whether or not they interacted with a scientist or engineer at the event, and whether or not the event increased their awareness of STEM careers. Attendee survey questions are shown in Figure 1.
EvalFest staff members used training videos to help ensure that field researchers at participating science expos used the same procedures to collect data from attendees. These videos included best practices for conducting intercept surveys, such as where a researcher should be located at the expo, how to systematically choose whom to survey, and how to track refusals.
#### 2.3 Analysis
The researchers used ordinal logistic regression to examine 5,498 survey responses for attendees of science expos at 14 science festivals around the United States. Specifically, a partial proportional odds (PPO) model was selected after an initial analysis of the data indicated that certain independent variables violated the proportional odds assumption. The proportional odds assumption, or parallel lines assumption, states that the effect of any independent variable upon a dependent variable is uniform across all categories (i.e. survey response ratings) of the dependent variable. A series of Wald tests indicated that this assumption did not hold for all of the independent variables selected for analysis (appendix A). In this case, the PPO model proves to be a more parsimonious alternative to the typical proportional odds model because it allows the effects of an independent variable to vary across each category of the dependent variable. In other words, the proportional odds assumption is relaxed for independent variables that are in violation of the assumption and constrained for variables that are not in violation. The PPO model for determining the probability that an attendee ($i$) provides a response that is at or above a given threshold ($j$), assuming there are $J$ categories of the dependent variable, can be specified as:
$P\left({Y}_{i}\ge j\right)={P}_{ij}=\frac{{e}^{\left({\alpha }_{j}+{X}_{i}{\beta }_{j}\right)}}{1+{e}^{\left({\alpha }_{j}+{X}_{i}{\beta }_{j}\right)}}\phantom{\rule{0ex}{0ex}}j=1,2,\dots ,J-1.$
In this equation, ${\alpha }_{j}$ are the cut points for the model, while ${\beta }_{j}$ represent the logit coefficients. The logit coefficients measure the effect of a one-unit change in an independent variable on the log-odds of a specific category of the dependent variable. Other categories are utilized as a basis for comparison. The logit coefficients may vary between outcomes, depending on whether or not a particular variable satisfies the proportional odds assumption.
The PPO analysis uses a series of model dichotomizations to estimate the odds that an attendee of a science expo will provide a response that is at or above a particular rating. Caution must be exercised in the interpretation of logit coefficients for intermediate ratings because the signs of these coefficients do not necessarily indicate the direction of an effect [Washington, Karlaftis and Mannering, 2011]. In order to facilitate interpretation of the results, adjusted predictions at representative values were examined. Adjusted predictions take specified values for independent variables and compute outcome probabilities for individuals with those characteristics. This allowed for a deeper investigation into the effect of scientist interaction by gender identity and URM status.
All statistical analyses were conducted in Stata using the gologit2 program [Williams, 2006]. A multilevel ordinal logistic regression was briefly considered, but an initial analysis indicated that only a small percentage of the variation in survey responses could be attributed to expo location. After running the unconditional (null) model for overall ratings, we found that the ratio of the between-expo variance and its standard error was 1.69. This value was not large enough to indicate that between-expo variance was significantly different from zero. Examining unconditional models with the other four outcomes yielded similar results with intraclass correlation coefficients less than .01. In facilitating the interpretation of results, a single-level model was preferred. Results from the four PPO models — overall ratings, learning, inspiration, and fun — are provided below. Analysis of variance inflation factors indicated that multicollinearity was not problematic.
A fifth survey outcome — awareness of STEM careers — is also included in this paper. Due to the binary and categorical nature of this outcome, a simple logistic regression analysis was preferred to the partial proportional odds model. A stepwise procedure determined that only one independent variable, scientist interaction, sufficiently contributed to survey responses for this outcome. Results from the simple logistic regression analysis are included below.
### 3 Results
Table 1 summarizes the descriptive statistics of the survey data. Nearly half (49%) of attendees identified as underrepresented minorities, while 61% identified as female. Survey responses were overwhelmingly positive for all five outcomes. A majority (53%) of attendees assigned the highest overall rating to the expo they attended. Most attendees either agreed or strongly agreed with statements related to learning (84%), inspiration (80%), and fun (92%). In addition, 83% of attendees attested to increased awareness of STEM career opportunities.
Table 1: Descriptive statistics (N = 5,498).
Logit coefficients, standard errors, and average adjusted predictions for the Likert scale outcomes — overall ratings, learning, inspiration, and fun — are reported in Tables 310. The tables also indicate which p-values proved to be significant and which independent variables violated the proportional odds assumption. If the proportional odds assumption was met for an independent variable, the logit coefficient is recorded only in the first column of the table. Wald test results from each model can be found in appendix A. Within each column, survey data are dichotomized to compare responses at or above specified levels. There are four such comparisons (Table 2). Simple logistic regression results for the fifth survey outcome, STEM career awareness, are reported in Table 11. Any missing data were excluded from the analysis.
Table 2: Probability comparisons.
#### 3.1 Analysis of overall ratings
In examining each outcome, positive logit coefficients are associated with higher odds that an attendee will rate a science expo at or above the specified threshold. For the first outcome, overall expo ratings, the gender variable has a logit coefficient of .319 for all thresholds (Table 3). This indicates that gender did not violate the proportional odds assumption and that female attendees were more likely to give higher overall ratings. A logit coefficient of .319 converts to an odds ratio of e${}^{0.319}$ = 1.38, indicating that females were 1.38 times as likely as males to assign an overall rating above a given threshold.
Table 3: Partial proportional odds model for overall ratings.
The scientist interaction variable failed to satisfy the proportional odds assumption and is therefore assigned a different logit coefficient for each threshold. Three of these coefficients were significant at the $\alpha$ = .001 level and were overwhelmingly positive. A logit coefficient of .777 is associated with an odds ratio of 2.15. In other words, attendees who interacted with a scientist were 2.15 times as likely to assign an expo the highest overall rating (5 = Excellent) as attendees who did not interact with a scientist.
In order to better parse out the effects of scientist interaction, adjusted predictions at representative values were generated. These values are obtained by selecting certain individual characteristics of attendees and computing the probabilities that attendees with those characteristics will assign specific overall ratings. This provides an intuitive and meaningful method for examining the effect of scientist interaction by race and gender. Adjusted predictions for overall ratings can be found in Table 4.
Table 4: Adjusted probabilities at representative values for overall ratings.
For female attendees, interacting with a scientist significantly increased the probability of assigning an expo the highest overall rating (.583), compared to female attendees who stated that they did not interact with a scientist (.394). The model predicts that female attendees who did not interact with a scientist are more likely to assign a rating of “good” or lower (.246 compared to .097 for female attendees who did interact with a scientist). A similar effect was observed for male attendees. Male attendees who interacted with a scientist were much more likely to assign a rating of “excellent” (.504) and much less likely to assign a rating of “good” or below (.129) than their counterparts who did not interact with a scientist (.321 and .310, respectively).
This trend persists even when parsing out the effect of scientist interaction by URM status. Attendees who identified as underrepresented minorities became much more likely to give an “excellent” rating if they interacted with a scientist (from .377 to .565). Those who did not identify as underrepresented minorities saw adjusted probabilities for “excellent” ratings increase from .353 to .540 when they interacted with a scientist. For both groups, the likelihood of assigning a rating “good” or below decreased in the presence of a scientist interaction.
#### 3.2 Analysis of learning
The second outcome for the model, learning, is an ordinal variable wherein attendees were asked to rate the extent to which they agreed with the statement: “I have learned something new at this event.” Table 5 contains the partial proportional odds results for this variable. None of the independent variables met the proportional odds assumption. Therefore, logit coefficients varied across each threshold.
Table 5: Partial proportional odds model for learning.
According to the results for the learning outcome, a logit coefficient of 0.183 implies that female respondents were 1.20 times as likely as males to strongly agree with the learning statement. Attendees who identified as underrepresented minorities were more likely to give the most extreme responses — strongly disagree and strongly agree — rather than intermediate responses. Increases in median income tended to solicit more intermediate responses rather than extreme responses. Scientist interaction once again proved to have the most dramatic effect on outcomes. A logit coefficient of 1.039 signifies that attendees who interacted with a scientist were 2.83 times as likely as other attendees to strongly agree with the learning statement.
Adjusted probabilities for learning are contained in Table 6. These values once again parse out the effect of scientist interaction by gender and URM status. For female attendees, interacting with a scientist increased the probability of strongly agreeing with the learning statement from .226 to .452. The adjusted predictions for all other responses decreased. For male attendees, interacting with a scientist increased the probability of strongly agreeing with the learning statement from .196 to .407. This effect held true regardless of whether or not attendees identified as underrepresented minorities (URM). For URM attendees, interacting with a scientist increased the adjusted prediction for “strongly agree” from .224 to .449. For non-URM attendees, the adjusted prediction increased from .204 to .420.
Table 6: Adjusted probabilities at representative values for learning.
#### 3.3 Analysis of inspiration
The third outcome for the model, inspiration, is an ordinal variable wherein attendees were asked to rate the extent to which they agreed with the statement: “I felt inspired by something I did in STEM”. Partial proportional odds analysis for the inspiration outcome is contained in Table 7. For this survey item, attendees were asked to rate the extent to which they agreed with the statement: “I felt inspired by something I did in STEM.” Only the scientist interaction variable violated the proportional odds assumption for this outcome. A logit coefficient of .156 indicates that female attendees were slightly more likely to give higher ratings for the inspiration statement. Across the board, attendees who interacted with a scientist were far more likely to give higher ratings than attendees who did not interact with a scientist. A logit coefficient of .906 indicates that attendees who interacted with a scientist were 2.47 times as likely as others to strongly agree with the inspiration statement. Logit coefficients for URM and median income did not prove to be significant for this outcome.
Table 7: Partial proportional odds model for inspiration.
Adjusted predictions for the inspiration outcome are contained in Table 8. Interacting with a scientist dramatically increased the probability of strongly agreeing with the inspiration statement regardless of gender identity or URM status. The adjusted predictions for “strongly agree” nearly doubled for every group: from 0.186 to 0.360 for females, from 0.164 to 0.326 for males, from 0.184 to 0.358 for underrepresented minorities, and from 0.171 to 0.337 for non-underrepresented attendees.
Table 8: Adjusted probabilities at representative values for inspiration.
#### 3.4 Analysis of fun
The fourth outcome variable asked attendees the extent to which they agreed with the statement: “I had fun at this event.” The partial proportional odds results for the fun outcome are reported in Table 9. In line with results for other outcomes, female attendees were more likely to strongly agree with the fun statement than male attendees. Scientist interaction demonstrated significant and positive effects across most of the thresholds. A logit coefficient of .921 indicates that attendees who interacted with a scientist were 2.51 times as likely as other attendees to strongly agree with the fun statement. Neither URM nor median income proved to be a significant predictor of this outcome.
Table 9: Partial proportional odds model for fun.
Adjusted predictions for the fun outcome are provided in Table 10. Once again, interacting with a scientist dramatically increased the predicted probability of falling into the “strongly agree” category. The scientist interaction increased the adjusted probability of a “strongly agree” response from .314 to .535 for females and from .251 to .456 for males. This adjusted probability increased from .297 to .514 for underrepresented minorities and from .280 to .492 for non-underrepresented attendees.
Table 10: Adjusted probabilities at representative values for fun.
#### 3.5 Analysis of STEM career awareness
The final survey outcome attempted to identify whether or not attendees’ awareness of STEM career opportunities increased after visiting these science expos. This item was formulated as a binary “yes” or “no” statement on the survey form. Due to the binary and categorical nature of the outcome, a simple logistic regression analysis was preferred to the partial proportional odds model. The gender, URM, and median income variables were excluded from this analysis after it was determined that they did not significantly contribute to the model.
A logit coefficient of 0.779 (Table 11) converts to an odds ratio of 2.18. Thus, attendees who interacted with a scientist were 2.18 times as likely to attest to increased awareness of STEM careers as those who did not interact with a scientist. The Wald z value of 5.82 (p < 0.001) indicates that scientist interaction was a significant predictor for the awareness outcome.
Table 11: Simple logistic regression results for STEM career awareness.
### 4 Discussion
The partial proportional odds results indicate that interacting with a scientist has a significant and positive effect on all of the survey items. On each of the four Likert scale items - overall rating, fun, inspiration, and learning - the probability of assigning the most favorable ratings increased dramatically for respondents who had interacted with a scientist at the expo they attended. Adjusted probabilities at representative values reinforced these findings for all of the survey items. On the binary outcome, awareness of STEM careers, respondents who interacted with a scientist were more likely to say that they became more knowledgeable about STEM career opportunities.
When the effect of scientist interaction was parsed out by gender and minority status, no striking differences were found between groups. Though female attendees were more likely to assign positive ratings in general, being able to interact with a scientist significantly increased the probability of assigning favorable ratings for both males and females. Similarly, although attendees who identified as underrepresented minorities were somewhat more likely to give favorable ratings in general, adjusted probabilities demonstrated that the effect of scientist interaction was overwhelmingly positive regardless of URM status.
These results support previous findings that the general public values and appreciates interactions with scientists and engineers. The results are also consistent with the evaluation data collected by Goodman Research Group for the Science Festival Alliance cited previously, where survey respondents rated events more positively if they interacted with STEM practitioners [Manning et al., 2012]. This study, in particular, begins to create a base of knowledge for the impacts scientists and engineers have on the public audiences with which they engage.
Although a good start at providing research where there has been little conducted, there are several limitations to this study. Survey data was collected by local teams at each of the 14 expos. These teams were trained to use identical protocols for attendee selection, but the differences between survey teams can add variability between individual sites. Additionally, these surveys were completed at events where it was extremely likely that respondents interacted with scientists and engineers. In fact, more than 90% of survey respondents indicated that they had interacted with a scientist and engineer, meaning that this study compared groups (interaction vs. no interaction) of vastly different sizes. However, the large sample size (n = 5,498) of the study and the robustness of the partial proportional odds model dramatically reduce the effects of unequal group sizes [Hsieh, 1989].
Since the survey did not ask specific questions about respondents’ income, income levels were inferred based upon their home zip code. Incomes can vary greatly within specific zip codes, therefore using this method also limits the generalizability of the study.
### 5 Conclusion
The results from the EvalFest survey data highlight the importance of bringing practicing scientists and engineers to public science events. When members of the public are able to interact with scientists and engineers, their self-perceptions of overall expo ratings, how much they are learning, how much they feel inspired, and how much fun they are having become significantly more favorable. Members of the public are also more likely to attest to increased awareness of STEM careers after interacting with a scientist. These results underline the need to train STEM professionals in effective public outreach and science communication. Further research on public-scientist interactions is needed to inform effective communication training. While this study collected demographic data only on attendees of science expos, future research may analyze the effect of scientists’ own racial and gender identities on public-scientist interactions.
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Rose, K. M., Korzekwa, K., Brossard, D., Scheufele, D. A. and Heisler, L. (2017). ‘Engaging the public at a science festival: findings from a panel on human gene editing’. Science Communication 39 (2), pp. 250–277. https://doi.org/10.1177/1075547017697981.
Washington, S. P., Karlaftis, M. G. and Mannering, F. L. (2011). Statistical and econometric methods for transportation data analysis. Boca Raton, FL, U.S.A.: Chapman & Hall/CRC.
Wiehe, B. (2018). Science festival alliance 2017 annual report. Cambridge, MA, U.S.A. URL: https://sciencefestivals.org/resource/2017-annual-report/.
Williams, R. (2006). ‘Generalized ordered logit/partial proportional odds models for ordinal dependent variables’. The Stata Journal: Promoting communications on statistics and Stata 6 (1), pp. 58–82. https://doi.org/10.1177/1536867x0600600104.
Woods-Townsend, K., Christodoulou, A., Rietdijk, W., Byrne, J., Griffiths, J. B. and Grace, M. M. (2016). ‘Meet the scientist: the value of short interactions between scientists and students’. International Journal of Science Education, Part B 6 (1), pp. 89–113. https://doi.org/10.1080/21548455.2015.1016134.
### Authors
Todd Boyette is the Director of Morehead Planetarium and Science Center and Adjunct Professor of Education at the University of North Carolina at Chapel Hill. He currently serves as Principal Investigator of EvalFest, a project sponsored by the National Science Foundation (U.S.) and designed to increase evaluation capacity within the U.S. science festival community. E-mail: [email protected].
J. Ross Ramsey is a doctoral student in Learning Sciences and Psychological Studies at the University of North Carolina at Chapel Hill School of Education and a former high school math teacher. He currently works as a graduate research assistant for the North Carolina Science Festival. E-mail: [email protected].
### How to cite
Boyette, T. and Ramsey, J. R. (2019). ‘Does the messenger matter? Studying the impacts of scientists and engineers interacting with public audiences at science festival events’. JCOM 18 (02), A02. https://doi.org/10.22323/2.18020202. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 8, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4505143463611603, "perplexity": 3870.1497372951794}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178351134.11/warc/CC-MAIN-20210225124124-20210225154124-00292.warc.gz"} |
http://luc.lino-framework.org/blog/2013/0121.html | # Merging two database records¶
Lino applications can now add a “Merge” action to any model. lino.core.merge
A typical use case are duplicate partners: a user realizes that due to human mistake a given company exists twice in their database, and each of them has certain number of events, invoices, contracts or other related things.
Clicking the “Merge” action on a Partner will ask “Merge this into” (select another Partner), and if you confirm, Lino will move all related data from this Partner to the other one, then delete the first one. Or in other words: if you discover a duplicate record, select the one that is “too much” (usually the one with the bigger id), then run the “Merge” action.
Technical challenges:
• this action also merges related objects linked through a generic foreign key.
• Since I wanted a generic solution it took me some time to figure out how to make Lino support ForeignKey to self for the other field of the action parameter dialog.
• “hard references” (e.g. contracts) are never deleted, but unconditionally moved to the target object. But for certain tables this can be disturbing: That’s why “soft references” (those who are lited in allow_cascaded_delete) may optionally be automatically deleted. The corresponding checkbox fields depend of course on the model, so this action is a first example of an automaically generated Layout.
I also used this occasion to make more intensive usage of Django’s Signals, a feature which I have been ignoring for far too long. lino.core.signals
The change also caused a few internal optimizations:
• Lino no longer uses copy.deepcopy to create copies of each action. (I guess I introduced this before BoundAction existed…)
• lino.ui.base.UI is now a new-style class because I override get_patterns and want to call super().
• AttributeError: ‘WSGIRequest’ object has no attribute ‘raw_post_data’ This was of course due to Django ticket #17323. That’s nice and no problem for me since Lino doesn’t need to run on Djangos before 1.4.2.
• When settings.DEBUG was off, then error messages didnt work because I had converted the error templates to Jinja, but Django’s TEMPLATE_LOADERS wasn’t correctly set (and lino.core.web.Loader had never been tested). This caused TemplateSyntaxErrors like “Could not parse the remainder: ‘(‘bootstrap’,’css’,’bootstrap.css’)’ from ‘site.build_media_url(‘bootstrap’,’css’,’bootstrap.css’)’” | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.32318663597106934, "perplexity": 3937.5584804332125}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267158011.18/warc/CC-MAIN-20180922024918-20180922045318-00514.warc.gz"} |
http://clay6.com/qa/81316/how-was-penicillin-discovered- | How was penicillin discovered?
How was penicillin discovered?
It was a chance discovery by Alexander Flemming that the growth of fungus Penicillium notatum killed bacteria Staphylococcus aureus. He found that the chemical extract of the fungus also possess the property of inhabiting the growth of bacteria. The chemical was named as penicillin. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9809068441390991, "perplexity": 13554.36456918067}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221216453.52/warc/CC-MAIN-20180820121228-20180820141228-00443.warc.gz"} |
https://www.ncbi.nlm.nih.gov/pubmed/2889793?dopt=Abstract | Format
Choose Destination
J Gen Microbiol. 1987 Jun;133(6):1631-9.
# glnA mutations conferring resistance to methylammonium in Escherichia coli K12.
### Author information
1
Centro de Investigación sobre Ingeniería Genética y Biotecnología, Universidad Nacional Autónoma de México, DF.
### Abstract
Cells of Escherichia coli K12 were sensitive to 100 mM-methylammonium when cultured under nitrogen limitation, and resistant when grown with an excess of either NH4Cl or glutamine. Glutamine synthetase activity was required for expression of the methylammonium-sensitive phenotype. Mutants were isolated which were resistant to 100 mM-methylammonium, even when grown under nitrogen limitation. P1 bacteriophage transduction and F' complementation analysis revealed that the resistance-conferring mutations mapped either inside the glnA structural gene and/or elsewhere in the E. coli chromosome. Glutamine synthetase was purified from the wild-type and from some of the mutant strains. Strains carrying glnA-linked mutations that were solely responsible for the methylammonium-resistant phenotype yielded an altered enzyme, which was less active biosynthetically with either ammonium or methylammonium as substrate. Sensitivity to methylammonium appeared to be due to synthesis of gamma-glutamylmethylamide by glutamine synthetase, which was synthesized poorly, if at all, by mutants carrying an altered glutamine synthetase enzyme.
PMID:
2889793
DOI:
10.1099/00221287-133-6-1631
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http://math.stackexchange.com/questions/87150/how-to-see-a-plane-is-tangent-to-a-sphere-from-their-equations | # How to see a plane is tangent to a sphere from their equations
Say you have two equations with three variables, the first is the equation of the surface of a sphere and the second of a plane. In this case they intersect in a point $(1,0,0)$. The only way I know to find this point is to rewrite the equation of the sphere so you know its center point and intersect a line going through that point at and at an angle of 90 degrees with the plane. Are there other methods to solve this? Without geometry?
Here are two example equations.
$$\begin{cases} x^2 + y^2 + z^2 - 6x + 6y - 12z + 5&=&0\\ 2x - 3y + 6 z - 2&=&0\\ \end{cases}$$
and the solution
$$\begin{cases} x = 1\\ y = 0\\ z = 0\\ \end{cases}$$
-
You mention two "equations" in three variables. I don't see any, an equation has an equals sign. Perhaps you mean $x^2+y^2+z^2-4x+6y-12z=0$, and $2x-3y+6z-2=0$. But perhaps not, since $(1,0,0)$ is not on the sphere with above equation. And ultimately, given right sphere and plane, there will often be infinitely many points of intersection. – André Nicolas Nov 30 '11 at 21:01
Without geometry? Why? My preference would be to find the distance from the centre to the plane --- compare with the radius and work from there using a projection onto the plane. – Jp McCarthy Nov 30 '11 at 23:26
Oh, I'm sorry I typed the wrong equation for the sphere. – Jus Dec 1 '11 at 17:33
Any sphere $S$ has equation $s(x,y,z)=0$, where $$s(x,y,z)=x^2+y^2+z^2-2ax-2by-2cz+d,$$ for some $d\lt a^2+b^2+c^2$. Any plane $P$ has equation $p(x,y,z)=0$, where $$p(x,y,z)=ux+vy+wz+t,$$ for some $(u,v,w)\ne(0,0,0)$. That $P$ is tangent to $S$ is equivalent to the condition that a point $(x,y,z)$ belongs to both $P$ and $S$, such that the line between the center $(a,b,c)$ of $S$ and $(x,y,z)$ is orthogonal to $P$.
The first part is $p(x,y,z)=s(x,y,z)=0$. The vector $(u,v,w)$ is orthogonal to $P$ hence the second part is that $(x-a,y-b,z-c)$ and $(u,v,w)$ are proportional.
Thus $(x,y,z)=(a+su,b+sv,c+sw)$ for some $\lambda$. Then $p(x,y,z)=0$ if and only if $$(u^2+v^2+w^2)\lambda=ua+bv+cw+t,$$ and $s(x,y,z)=0$ if and only if $$(u^2+v^2+w^2)\lambda^2=a^2+b^2+c^2-d.$$ Thus $P$ plane is tangent to $S$ if and only if these two equations have a common solution $\lambda$, that is, $$(ua+bv+cw+t)^2=(u^2+v^2+w^2)\cdot(a^2+b^2+c^2-d).$$
-
First, a sphere and plane can intersect in a circle, a point, or not at all. As André Nicolas has said, $(1,0,0)$ does not satisfy your equations. For your equations, Alpha shows that the intersection is a circle, not a point.
With the new equation, Alpha still thinks there are more than one point of intersection. The first is now $(x-3)^2+(y+3)^2+(z-6)^2=7^2$ so $(1,0,0)$ is an intersection.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9372687339782715, "perplexity": 109.5758769912582}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440644059993.5/warc/CC-MAIN-20150827025419-00159-ip-10-171-96-226.ec2.internal.warc.gz"} |
https://scicomp.stackexchange.com/questions/28608/when-numerically-computing-eigenstates-during-a-coupled-mode-space-negf-calculat | # When numerically computing eigenstates during a coupled-mode-space NEGF calculation, do phases matter?
The coupled mode space NEGF method for computing transistor characteristics involves expanding the electronic wavefunction in a mode space basis
$$\Psi(x,y,z) = \sum_n\phi_n(x)\xi_n(y,z;x)$$
where $\xi_n(y,z;x)$ is the nth mode at position x (the x dimension being the direction of transport).
The method involves computing coupling between modes along the transport direction. E.g. coupling coefficients like
$$b_{mn}(x) = \langle\xi_m|\frac{\partial}{\partial x}|\xi_n\rangle$$
The numerical algorithm will divide the transistor into $X$ slices $\Delta x$ apart, and compute the modes on each slice. The issue is my numerical solver will sometimes compute $\xi_n$ as the nth eigenvalue, and sometimes compute $-\xi_n$, so phases might not be consistent across each slice. This changing phase will result in a large $\frac{\partial}{\partial x}|\xi_n\rangle$
My question is: Do the phases need to be consistent across each slice? If they do, how do NEGF algorithms ensure they are consistent?
• The phases do not matter here, in the calculation of the first derivative they are naturally factored out. Moreover, think about using $\Psi(x,y,z) = \sum_n\phi_n(x)\xi_n(y,z)$ as your ansatz -- note the missing $x$ in $\xi$. That makes thing a lot easier. – davidhigh Jan 15 '18 at 13:44
• Hmm, I include the $x$ in order to track how the modes change with $x$. E.g. $\frac{\partial}{\partial x}\xi_n(y,z;x) = \frac{\xi_n(y,z;x+\Delta x)-\xi_n(y,z;x)}{\Delta x}$, which is only 0 if the modes are the same at each $x$. – DJames Jan 15 '18 at 18:24
• The "modes" are eigenfunctions of your Hamiltonian, I suppose? If so, you can make the ansatz $\Psi(x,y,z) = \sum_n c_n \xi_n(y,z;x)$. i.e. an expansion in your modes. I don't get, however, why you should have two $x$'es. That complicates everything. Can you please explain? – davidhigh Jan 15 '18 at 22:04
• You can find a detailed description of the method in this paper: arxiv.org/ftp/cond-mat/papers/0403/0403739.pdf . In this case, the modes aren't eigenfunctions of the full Hamiltonian. Instead they would be eigenfunctions of the 2D Hamiltonian defined at each position $x$ along the device – DJames Jan 16 '18 at 13:37 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6752493977546692, "perplexity": 645.2774795696552}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247494125.62/warc/CC-MAIN-20190220003821-20190220025821-00307.warc.gz"} |
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# A Summer of Maths
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1. I haven't done any maths for like 2 weeks and I already feel rusty :/
2. What is the derivative of y=x^x?
What is the derivatie and inverse of y=x^x^x^x^... (an infinite string of x's)
Here x^x^x=x^(x^x) not (x^x)^x
Also for what values of x does y exist?
3. (Original post by Brit_Miller)
I have a question but not an answer as I don't know how to do it. Hopefully someone can show how.
Let
I have never done anything like this so the following is possibly wrong. Even if it is correct I'm sure there's a much prettier way of doing it:
Spoiler:
Show
(for the bijection proof)
Suppose there exists such that
We would have:
Clearly
Furthermore:
Now consider the functions and
The above equality is satisfied when
Obviously is strictly increasing. Differentiating with respect to gives so decreases. Therefore has only one solution, namely . But this is defies our initial conditions.
Therefore is bijective.
4. (Original post by Brit_Miller)
I have a question but not an answer as I don't know how to do it. Hopefully someone can show how.
Let
Spoiler:
Show
Lemma 1. The cube of a negative number is the negative of its magnitude cubed.
Spoiler:
Show
Suppose that, for some , we have
where is non-negative.
Now, if we take for granted that , we continue by
Therefore, since the result is trivially true for , we get
as desired.
Lemma 2 (Corollary of Existence of n-th roots). Two cubes are equal if and only if the are the same.
Spoiler:
Show
Existence of n-th roots:
If is positive, and , then there exists exactly one positive real number such that .
By Lemma 1, we can always write as
but then the above theorem says that they must be equal.
{**} A solution:
Spoiler:
Show
We want to show that is injective and surjective which would imply that it is bijective.
[1] Suppose that with and at least one of and holds.
Then, we obtain the following two equations.
Using Lemma 2, we see from that , and by substituting into we get
which contradicts our assumption. Therefore, is injective.
[2] We show surjectivity by existence.
Take any . Then, it suffices to show that such that and .
We find that and where by applying Lemmas 1 & 2.
Therefore, is bijective.
Now, its inverse is given by
Spoiler:
Show
Lemma 1. The cube of a negative number is the negative of its magnitude cubed.
Spoiler:
Show
Suppose that, for some , we have
where is non-negative.
Now, if we take for granted that , we continue by
Therefore, since the result is trivially true for , we get
as desired.
Lemma 2 (Corollary of Existence of n-th roots). Two cubes are equal if and only if the are the same.
Spoiler:
Show
Existence of n-th roots:
If is positive, and , then there exists exactly one positive real number such that .
By Lemma 1, we can always write as
but then the above theorem says that they must be equal.
{**} A solution:
Spoiler:
Show
We want to show that is injective and surjective which would imply that it is bijective.
[1] Suppose that with and at least one of and holds.
Then, we obtain the following two equations.
Using Lemma 2, we see from that , and by substituting into we get
which contradicts our assumption. Therefore, is injective.
[2] We show surjectivity by existence.
Take any . Then, it suffices to show that such that and .
We find that and where by applying Lemmas 1 & 2.
Therefore, is bijective.
Now, its inverse is given by
Nice - and informative too! I guess I was completely off the map on this one.
6. (Original post by Lord of the Flies)
Nice - and informative too! I guess I was completely off the map on this one.
You can add some bits to it, and fix some, but in general I don't think you were off the map at all. (not that I am much on the map, but anyway)
For instance, , so that is a point in the plane.
The function is a mapping from points on the plane to points on the real plane; i.e. .
Spoiler:
Show
Lemma 1. The cube of a negative number is the negative of its magnitude cubed.
Spoiler:
Show
Suppose that, for some , we have
where is non-negative.
Now, if we take for granted that , we continue by
Therefore, since the result is trivially true for , we get
as desired.
Lemma 2 (Corollary of Existence of n-th roots). Two cubes are equal if and only if the are the same.
Spoiler:
Show
Existence of n-th roots:
If is positive, and , then there exists exactly one positive real number such that .
By Lemma 1, we can always write as
but then the above theorem says that they must be equal.
{**} A solution:
Spoiler:
Show
We want to show that is injective and surjective which would imply that it is bijective.
[1] Suppose that with and at least one of and holds.
Then, we obtain the following two equations.
Using Lemma 2, we see from that , and by substituting into we get
which contradicts our assumption. Therefore, is injective.
[2] We show surjectivity by existence.
Take any . Then, it suffices to show that such that and .
We find that and where by applying Lemmas 1 & 2.
Therefore, is bijective.
Now, its inverse is given by
Nicely done!
8. Is anyone interested in summing up
where is a positive integer? Ideas how we can do this?
Is anyone interested in summing up
where is a positive integer? Ideas how we can do this?
Without doing any mathematics, I think that should diverge. For large n the value of x can be ignored so n!/(n+x)! is approximately 1 so it must diverge.
EDIT: After doing some maths, it seems that the above reasoning is flawed, the terms do indeed tend to 0 so it may converge.
10. (Original post by james22)
Without doing any mathematics, I think that should diverge. For large n the value of x can be ignored so n!/(n+x)! is approximately 1 so it must diverge.
Take x = 2, then n!/(n+2)! = 1/(n+1)(n+2) which converges.
Is anyone interested in summing up
where is a positive integer? Ideas how we can do this?
Spoiler:
Show
I'd start off by noting that , which should converge for .
I'll finish it off when I get back if someone hasn't already.
12. subscribing.....around 2 in the night I tend to get bored
13. (Original post by Lord of the Flies)
Spoiler:
Show
If is the number of powers of we can define:
In particular
I don't believe it is possible to express the inverse in the form though.
Sorry I wasn't clear, there are meant to be infinite x's.
As a side question to it, for what values of x is f(x) defined?
14. (Original post by james22)
Sorry I wasn't clear, there are meant to be infinite x's.
As a side question to it, for what values of x is f(x) defined?
Ah. In any case my working is wrong, I stupidly misread the question!...
... which makes the question more difficult, but more interesting! Hm...
Spoiler:
Show
Lemma 1. The cube of a negative number is the negative of its magnitude cubed.
Spoiler:
Show
Suppose that, for some , we have
where is non-negative.
Now, if we take for granted that , we continue by
Therefore, since the result is trivially true for , we get
as desired.
Lemma 2 (Corollary of Existence of n-th roots). Two cubes are equal if and only if the are the same.
Spoiler:
Show
Existence of n-th roots:
If is positive, and , then there exists exactly one positive real number such that .
By Lemma 1, we can always write as
but then the above theorem says that they must be equal.
{**} A solution:
Spoiler:
Show
We want to show that is injective and surjective which would imply that it is bijective.
[1] Suppose that with and at least one of and holds.
Then, we obtain the following two equations.
Using Lemma 2, we see from that , and by substituting into we get
which contradicts our assumption. Therefore, is injective.
[2] We show surjectivity by existence.
Take any . Then, it suffices to show that such that and .
We find that and where by applying Lemmas 1 & 2.
Therefore, is bijective.
Now, its inverse is given by
Nice
The following result could of been quoted to make your answer alot shorter (though it's always good practice to do things straight from the definitions)
Related exercise:
Let
g is said to be a left [or right] inverse of f if respectively
Show that f is surjective iff it has a right inverse
Show that f is injective iff it has a left inverse
Hence a map is bijective iff it has an (left and right) inverse. (an g is said to be an inverse iff g is both a left and right inverse.)
Using this, you only need to verify that your inverse is an inverse .
16. {*} Question:
The polynomial is irreducible over .
i) By completing the square, show that is not irreducible over the set of real numbers.
Hence, derive the Sophie Germain algebraic identity
by starting from the left-hand side.
ii) Evaluate
{**} Required:
Spoiler:
Show
A polynomial is said to be irreducible over a set if it cannot be factored into polynomials with coefficients from the given set.
As an example,
is irreducible over the set of rational numbers denoted by .
17. Okay, I have another question which I'm sure is relatively simple and someone will know (sorry for using the thread without answers, but it's a nice place to ask questions!)
Consider this 2nd order differential equation:
Write this as a system of 1st order equations with appropriate initial conditions.
18. (Original post by Brit_Miller)
Okay, I have another question which I'm sure is relatively simple and someone will know (sorry for using the thread without answers, but it's a nice place to ask questions!)
Consider this 2nd order differential equation:
Write this as a system of 1st order equations with appropriate initial conditions.
Let z=y'.
Also quite easy: How many (real) solutions does have? Knowledge required: GCSE & below.
19. In an office, at various times during the day, the boss gives the secretary a letter to type, each time putting the letter on top of the pile and types it. There are nine letters to be typed during the day, and the boss delivers them in the order 1,2,3,4,5,6,7,8,9. While leaving for lunch, the secretary tells a colleague that letter 8 has already been typed, but says nothing about the morning's typing. The colleague wonders which of the nine letters remain to be typed after lunch and in what order they will be typed. Based on the above information, how many such after-lunch typing orders are possible? (That there are no letters to be typed is on of the possibilities).
No ugrad knowledge required beyond combinations/ permutations.
20. (Original post by electriic_ink)
Let z=y'.
Also quite easy: How many (real) solutions does have? Knowledge required: GCSE & below.
Thanks
(and none surely?)
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https://proofwiki.org/wiki/Mathematician:Mathematicians/Sorted_By_Nation/United_States | Mathematician:Mathematicians/Sorted By Nation/United States
For more comprehensive information on the lives and works of mathematicians through the ages, see the MacTutor History of Mathematics archive, created by John J. O'Connor and Edmund F. Robertson.
The army of those who have made at least one definite contribution to mathematics as we know it soon becomes a mob as we look back over history; 6,000 or 8,000 names press forward for some word from us to preserve them from oblivion, and once the bolder leaders have been recognised it becomes largely a matter of arbitrary, illogical legislation to judge who of the clamouring multitude shall be permitted to survive and who be condemned to be forgotten.'
-- Eric Temple Bell: Men of Mathematics, 1937, Victor Gollancz, London
USA
1801 – 1850
Benjamin Peirce (1809 – 1880)
American mathematician and logician who has been called "The founding father of modern abstract algebra".
Like George Boole, attempted to put logic on a sound mathematical footing.
He also contributed to many other areas of mathematics.
Proved that there is no odd perfect number with fewer than four prime factors.
Introduced the terms idempotence and nilpotence in $1870$, in his work Linear Associative Algebra.
Father of Charles Sanders Peirce.
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Elias Loomis (1811 – 1889)
American mathematician and physicist best known for his textbooks.
Also known for his thorough investigation into the geomagnetic storm of 1859.
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Edward J. Goodwin (1825 – 1902)
Indiana physician and amateur mathematician who believed he had squared the circle, trisected the angle and doubled the cube.
He proposed a bill to allow for the charging of royalties for the use of the value of $\pi$ (pi) that he had calculated.
It was rejected before the second reading through the efforts of Clarence Abiathar Waldo.
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Josiah Willard Gibbs (1839 – 1903)
American scientist who made important theoretical contributions to physics, chemistry, and mathematics.
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Charles Sanders Peirce (1839 – 1914)
American chemist who contributed to the fields of logic and mathematical philosophy, in particular the theory of the use of signs.
Laid some of the groundwork for the mathematical discipline of category theory.
Perceived in $1886$ that the functions of logic can be carried out by electronic circuitry.
Samuel Loyd (1841 – 1911)
American chess player, chess composer, puzzle author, and recreational mathematician.
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Wooster Woodruff Beman (1850 – 1922)
American mathematician best known for his text books and translations.
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1851 – 1900
Clarence Abiathar Waldo (1852 – 1926)
American mathematician, author and educator today most famous for the role he played in the Indiana Pi Bill affair.
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George Arthur Plimpton (1855 – 1936)
American publisher and philanthropist, whose contribution to mathematics was his collection of rare ancient mathematical works which he donated to the Nicholas Murray Butler Library of Columbia University.
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Florian Cajori (1859 – 1930)
Swiss-born American mathematician who specialized in (and in fact pioneered) the field of mathematics history.
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David Eugene Smith (1860 – 1944)
American mathematician and educator best known for his translations of classics.
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Frank Nelson Cole (1861 – 1926)
American mathematician famous for finding the factors of the Mersenne number $M_{67}$. (It had already been demonstrated by Édouard Lucas in $1876$ that it is not prime, but till this time the factors had not been found.) Cole's demonstration of this in $1903$ took the form of a now famous lecture On The Factorization of Large Numbers in which he performed the necessary arithmetic on a blackboard, delivering the only totally wordless lecture in recorded history.
The American Mathematical Society's Cole Prize was named in his honor.
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Eliakim Hastings Moore (1862 – 1932)
American mathematician working in abstract algebra and the foundations of geometry, among others.
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William Fogg Osgood (1864 – 1943)
American mathematician working in complex analysis, in particular conformal mapping and uniformization of analytic functions, and calculus of variations.
Wrote on the theory of the gyroscope.
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James P. Pierpont (1866 – 1938)
American mathematician working first in Galois theory, and then in real and complex analysis.
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Derrick Norman Lehmer (1867 – 1938)
American mathematician active mainly in the field of number theory.
The father of Derrick Henry ("Dick") Lehmer.
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Charles Albert Noble (1867 – 1962)
American mathematician who worked mainly on differential equations.
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Maxime Bôcher (1867 – 1918)
American mathematician who worked on differential equations, series, and algebra.
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Horace Scudder Uhler (1872 – 1956)
American physicist who worked on geometrical optics, spectroscopy and X-rays.
As a mathematician, demonstrated several Mersenne numbers to be composite without finding one single Mersenne prime.
Also calculated the values of many irrational numbers such as logarithms, reciprocals and roots to a colosssal number of decimal places.
Published the value of $\log_{10} \left({9^{9^9} }\right)$ to $250$ decimal places in $1947$.
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Julian Lowell Coolidge (1873 – 1954)
American mathematician and a professor and chairman of the Harvard University Mathematics Department.
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Leonard Eugene Dickson (1874 – 1954)
One of the first American mathematicians to work in abstract algebra.
Also remembered for his history of number theory.
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Edward Vermilye Huntington (1874 – 1952)
American mathematician who worked on the foundations of mathematics.
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Frank Lauren Hitchcock (1875 – 1957)
American mathematician and physicist known for his formulation of the transportation problem in $1941$.
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Gilbert Ames Bliss (1876 – 1951)
American mathematician, known for his work on the calculus of variations.
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Earle Raymond Hedrick (1876 – 1943)
American mathematician who adopted the position of vice-president of the University of California.
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Edward Kasner (1878 – 1955)
American mathematician best known now for coining the terms googol and googolplex.
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Robert Daniel Carmichael (1879 – 1967)
American mathematician who contributed mainly to the fields of differential equations and number theory.
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John Wesley Young (1879 – 1932)
American mathematician who introduced the axioms of projective geometry with Oswald Veblen.
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Oswald Veblen (1880 – 1960)
American mathematician, geometer and topologist, whose work found application in atomic physics and the theory of relativity.
Proved the Jordan Curve Theorem in 1905.
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Henry Maurice Sheffer (1882 – 1964)
American logician famous for proving in $1913$ that the logical NAND operator is functionally complete. (This had previously been noted by Charles Sanders Peirce in $1880$ but not published till $1933$.)
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Percy Williams Bridgman (1882 – 1961)
American physicist awarded for his work on the physics of high pressures.
Wrote extensively on the scientific method and other aspects of the philosophy of science.
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Harry Schultz Vandiver (1882 – 1973)
American mathematician known for his work in number theory.
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Clarence Irving Lewis (1883 – 1964)
American philosopher logician recognized as being a leading authority on symbolic logic.
An early proponent of the work of Charles Sanders Peirce, and also referenced the logical works of Gottfried Wilhelm von Leibniz.
Did considerable work to analyze the semantic meaning of the conditional statement.
Analyzed modal logic.
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James Henry Weaver (1883 – 1942)
American mathematician who co-authored books with Robert Daniel Carmichael.
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George David Birkhoff (1884 – 1944)
American mathematician best known for what is now known as the Ergodic Theorem.
The father of Garrett Birkhoff.
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Frank Hyneman Knight (1885 – 1972)
American economist whose work inspired some of the early developments in game theory.
Developed the argument which was eventually named Wardrop's Principle (for John Glen Wardrop).
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Louis Joel Mordell (1888 – 1972)
American-born British mathematician known for his pioneering research in number theory.
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James Waddell Alexander II (1888 – 1971)
American mathematician who did pioneering work in topology and knot theory.
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William Frederick Friedman (1891 – 1969)
American cryptographer instrumental in breaking Japan's PURPLE cipher before America's entrance into World War II.
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Herman Lyle Smith (1892 – 1950)
American mathematician who worked in the field of set theory.
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Norbert Wiener (1894 – 1964)
American mathematician who worked mainly in computer science, stochastic processes and cybernetics.
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Raymond Louis Wilder (1896 – 1982)
American mathematician best known for his writing on the subject of the philosophy of mathematics.
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Lincoln La Paz (1897 – 1985)
American mathematician and pioneer in the field of meteorics.
During World War II, served as research mathematician at the New Mexico Proving Grounds.
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Charles Wilderman Trigg (1898 – 1989)
American engineer, mathematician and educator.
Best known nowadays for his work in the field of recreational mathematics.
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David Vernon Widder (1898 – 1990)
American mathematician mainly working in analyis.
He was highly regarded for his teaching abilities.
The author of the textbook Advanced Calculus.
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Ruel Vance Churchill (1899 – 1987)
American mathematician best known for his textbooks.
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John Clarke Slater (1900 – 1976)
American physicist who made major contributions to the theory of the electronic structure of atoms, molecules and solids.
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1901 – 1930
Joseph Warner Howe (1902 – 1983)
American physicist working mainly in the field of fluid mechanics and hydraulics.
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Carolyn Eisele (1902 – 2000)
American mathematician and historian of mathematics known as an expert on the works of Charles Sanders Peirce.
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Hubert Stanley Wall (1902 – 1971)
American mathematician who worked primarily in the field of continued fractions.
One of the leading proponents of the Moore method of teaching.
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Marshall Harvey Stone (1903 – 1989)
American mathematician who contributed to real analysis, functional analysis, and the study of boolean algebras.
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John Francis Riordan (1903 – 1988)
American mathematician and the author of major early works in combinatorics.
Also contributed significantly to the world of literature and poetry.
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Alonzo Church (1903 – 1995)
American mathematician who pioneered in the field of computability theory and the foundations of computer science.
Best known for his lambda calculus, Church's Theorem and Church's Thesis.
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John von Neumann (1903 – 1957)
Hungarian-American mathematician who made major contributions to a vast range of fields, including set theory, functional analysis, quantum mechanics, ergodic theory, continuous geometry, economics, computer science, numerical analysis and statistics, to name but a few.
Founded the field of game theory in collaboration with Oskar Morgenstern.
Generally regarded as one of the foremost mathematicians in modern history.
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Edward James McShane (1904 – 1989)
American mathematician noted for his advancements of the calculus of variations, integration theory, stochastic calculus, and exterior ballistics.
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Derrick Henry Lehmer (1905 – 1991)
Derrick Henry ("Dick") Lehmer was an American mathematician active mainly in the field of number theory.
Most famous for designing the Lucas-Lehmer Test for determining the primality of Mersenne numbers.
The son of Derrick Norman Lehmer, and married to Emma Lehmer, née Trotskaia.
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Hunter Rouse (1906 – 1996)
American physicist working mainly in the field of fluid mechanics and hydraulics.
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Carl Benjamin Boyer (1906 – 1976)
American historian of mathematics and science.
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James Roy Newman (1907 – 1966)
American mathematician and historian of mathematics best known for his writings and popularisations.
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Hassler Whitney (1907 – 1989)
American mathematician who worked mainly in topology.
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Holbrook Mann MacNeille (1907 – 1973)
American mathematician who worked for the United States Atomic Energy Commission before becoming the first Executive Director of the American Mathematical Society.
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Edwin Mattison McMillan (1907 – 1991)
American physicist and working in nuclear science.
Also worked on the mathematics of computation.
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John Barkley Rosser Sr. (1907 – 1989)
American logician best known for his work in mathematical logic.
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John Charles Chenoweth McKinsey (1908 – 1953)
American mathematician best known for his work on mathematical logic and game theory. He also made significant contributions to modal logic.
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Morris Kline (1908 – 1992)
American physicist, mathematics teacher, historian, and agitator for the teaching of the New Mathematics in schools.
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Willard Van Orman Quine (1908 – 2000)
Legendary American philosopher and logician, known by his friends as Van.
Proposed three systems of axiomatic set theory.
The word quine was coined by Douglas R. Hofstadter in his classic 1979 work Gödel, Escher, Bach: an Eternal Golden Braid, in which what is now known as Quine's paradox was discussed at length.
The word quine is now used for a computer program whose output is itself.
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Stephen Cole Kleene (1909 – 1994)
American mathematician best known as one of the great pioneers in the field of recursion theory.
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Arthur Sard (1909 – 1980)
American mathematician, famous for his work in differential topology and in spline interpolation.
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Saunders Mac Lane (1909 – 2005)
American mathematician who cofounded category theory with Samuel Eilenberg.
Introduced the diagrammatic approach to mathematics, in particular pioneering the use of commutative diagrams.
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Nathan Jacobson (1910 – 1999)
Polish-American mathematician mainly working in abstract algebra.
Student of Joseph Henry Maclagan Wedderburn.
Known as Jake to his friends and colleagues.
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Anthony Perry Morse (1911 – 1984)
American mathematician who worked both in analysis, especially measure theory, and in the foundations of mathematics.
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George Joseph Stigler (1911 – 1991)
American economist.
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Garrett Birkhoff (1911 – 1996)
American mathematician mainly working in mathematical physics and abstract algebra.
Also wrote plenty of text books: his Lattice Theory (1940) is much cited.
The son of George David Birkhoff.
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John William Wrench, Jr. (1911 – 2009)
American mathematician working mainly in numerical analysis.
Pioneer of the use of computers for mathematical calculations
Best known now for his work with Daniel Shanks to calculate $\pi$ to $100 \, 000$ decimal places.
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Raphael Mitchel Robinson (1911 – 1995)
American mathematician who worked on mathematical logic, set theory, geometry, number theory and combinatorics.
One of the early computer pioneers, he implemented a program for the Lucas-Lehmer Test and in 1952 determined or confirmed the primality of all the Mersenne numbers up to $M_{2304}$. In the process, he discovered the Mersenne primes $M_{521}, M_{607}, M_{1279}, M_{2203}$ and $M_{2281}$.
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Arthur Norton Milgram (1912 – 1961)
American mathematician who worked on functional analysis, combinatorics, differential geometry, topology, partial differential equations, and Galois theory.
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Ralph Philip Boas, Jr. (1912 – 1992)
American mathematician, teacher, and journal editor, working mainly in the fields of real and complex analysis.
Best known for his humorous applications of mathematical theorems to the practical purpose of hunting lions.
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Charles Stanley Ogilvy (1913 – 2000)
American mathematician also well-known for being a sailor.
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Abraham Charnes (1913 – 1992)
American mathematician who worked in the area of operations research.
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Rufus Philip Isaacs (1914 – 1981)
American game theorist known for his work on differential games.
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William Wager Cooper (1914 – 2012)
American operations researcher known for developing the field of linear programming.
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Robert Osher Schlaifer (1914 – 1994)
American statistician who was one of the pioneers of Bayesian decision theory.
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Martin Gardner (1914 – 2010)
American mathematician and magician best known for the books he wrote (of which there were many) popularizing mathematics and science.
Author of the Mathematical Games column in Scientific American between 1956 and 1981. This position was taken over by Douglas R. Hofstadter.
Also contributed a series of "puzzle page" articles for Isaac Asimov's Science Fiction Magazine in the late 1970's to early 1980's.
Also wrote a column called Notes of a Fringe Watcher (originally Notes of a Psi-Watcher) from 1983 to 2002 for the Committee for Skeptical Inquiry's periodical Skeptical Inquirer.
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Milton Abramowitz (1915 – 1958)
American mathematician who made his mark co-editing the Handbook of Mathematical Functions with Irene Ann Stegun.
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Robert Henry Sorgenfrey (1915 – 1995)
American mathematician who made significant contributions to the field of topology.
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Herbert Ellis Robbins (1915 – 2001)
American mathematician and statistician who did research in topology, measure theory, statistics, and a variety of other fields.
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Richard Wesley Hamming (1915 – 1998)
American mathematician best known for his work on error-detecting codes.
Thus he started a new field of study within information theory.
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John Wilder Tukey (1915 – 2000)
American mathematician working mainly in the field of statistics.
Best known for development of the FFT algorithm and box plot.
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Wilfred Kaplan (1915 – 2007)
American professor of mathematics whose research focused on dynamical systems, the topology of curve families, complex function theory, and differential equations.
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Bryant Tuckerman (1915 – 2002)
American mathematician who discovered, on March 4th, $1971$, the 24th Mersenne prime: $2^{19 \, 937} - 1$.
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Selmer Martin Johnson (1916 – 1996)
American mathematician working on number theory and optimisation problems.
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Nathan Jacob Fine (1916 – 1994)
American mathematician who worked on basic hypergeometric series.
Best known for his lecture notes on the subject which were used as a standard, until they were finally published as a book.
Solved the Jeep Problem in $1946$.
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Robert Dorfman (1916 – 2002)
American mathematician who made contributions to the fields of economics, group testing and in the process of coding theory.
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John Leroy Kelley (1916 – 1999)
American mathematician best known for his work on topology and functional analysis.
Author of the widely-used and -cited textbook General Topology, and others.
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Daniel Shanks (1917 – 1996)
American mathematician who worked primarily in numerical analysis and number theory.
Best known as the first to compute $\pi$ to $100 \, 000$ decimal places.
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Irving Marmer Copi (1917 – 2002)
American philosopher and mathematician best known for his university textbooks.
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Leonard Jimmie Savage (1917 – 1971)
American mathematician who worked on metric and differential geometry, calculus of variations and statistics.
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Elizabeth Leonard Scott (1917 – 1988)
American mathematician active in the field of group theory, but more well-known for her work in astronomy.
Also involved (with Jerzy Neyman) in the science of rainmaking by cloud seeding.
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Jacques Dutka (1919 – 2002)
American mathematician who was the first to calculate the square root of $2$ to more than one million digits.
Also wrote extensively on the history of mathematics.
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Harry Pollard (1919 – 1985)
American mathematician noted for his work in celestial mechanics and the $n$-body problem.
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Irene Ann Stegun (1919 – 2008)
American mathematician who took over the work of co-editing the Handbook of Mathematical Functions from Milton Abramowitz, who died in 1958 before the work was complete.
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David Harold Blackwell (1919 – 2010)
American mathematician who focused mainly on statistics and game theory.
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Raymond Merrill Smullyan (1919 – 2017)
Raymond Merrill Smullyan (known as "Ray") was an American mathematician and logician, noted for the accessibility of his books on logic.
He also was a concert pianist and magician.
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Donald Kalish (1919 – 2000)
American logician, also known as an activist against the Vietnam war.
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Julia Hall Bowman Robinson (1919 – 1985)
American mathematician best known for her work on decision problems and Hilbert's Tenth Problem.
Born Julia Hall Bowman.
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William Kay Smith (1920 – 2007)
American mathematician working in education and real analysis.
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Richard Ernest Bellman (1920 – 1984)
American applied mathematician, who introduced dynamic programming in 1953, and important contributions in other fields of mathematics.
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Carlton Edward Lemke (1920 – 2004)
American mathematician, working in Algebra, Mathematical Programming, Operations Research, and Statistics.
Also contributed to game theory.
Developed the dual simplex method in $1954$, independently from E.M.L. Beale.
With J.T. Howson, Constructed an algorithm in $1964$ for finding Nash equilibria the case of finite two-person games, for which he received the John von Neumann Theory Prize in $1978$.
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Marion Kirkland Fort, Jr (1921 – 1964)
M. K. Fort, Jr., known as Kirk, was an American mathematician specialising in topology.
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Robert Clay Prim (b. 1921 )
American mathematician working mainly in the field of computer science.
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Thomas Crombie Schelling (1921 – 2016)
American economist and professor of foreign policy, national security, nuclear strategy, and arms control.
An authority on game theory.
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Leon Albert Henkin (1921 – 2006)
American logician best known for Henkin's Completeness Proof.
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Harry Jeannot Lipkin (b. 1921 )
American-born Israeli theoretical physicist specializing in nuclear physics and elementary particle physics.
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Verner Emil Hoggatt Jr. (1921 – 1980)
American mathematician, known mostly for his work in Fibonacci numbers and number theory.
Founder of the Fibonacci Association.
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Angelo Margaris (1921 – 2006)
American mathematician best known for his textbook First Order Mathematical Logic.
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Patrick Colonel Suppes (1922 – 2014)
American philosopher who has written on a variety of subjects, including mathematics.
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Friend Hans Kierstead, Jr. (1922 – 2008)
American mathematician who was the problem editor of the Journal of Recreational Mathematics.
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Henry Andrew Kierstead (1922 – 1990)
American mathematician who contributed to the Journal of Recreational Mathematics.
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George Brown Arfken (b. 1922 )
American theoretical physicist and author of several mathematical physics texts.
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Harvey Cohn (1923 – 2014)
American mathematician who majored in number theory.
Pioneered the use of computers for mathematical investigations.
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Philip J. Davis (1923 – 2018)
American mathematician whose main work is in numerical analysis and approximation theory.
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William Judson LeVeque (1923 – 2007)
American mathematician and administrator who worked primarily in number theory.
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Tom Mike Apostol (1923 – 2016)
American mathematician of Greek origin best known for his textbooks and skill as a teacher.
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Murray Ralph Spiegel (1923 – 1991)
American mathematician whose main body of work consists of a series of technical books on applied mathematics.
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Howard Raiffa (b. 1924 )
American mathematician who mainly works in game theory and economics.
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John Warner Backus (1924 – 2007)
American computer scientist, significantly involved in the development of several computer languages, including ALGOL and FORTRAN.
The metalanguage Backus-Naur Form (BNF) was named after him (who invented it) and Peter Naur (who refined it).
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Mary Ellen Rudin (1924 – 2013)
American topologist best known for creating counterexamples to conjectures in point-set topology, and especially for being the first person to construct a Dowker Space, disproving a long-standing conjecture.
Born Mary Ellen Estill, under which name she published several papers before her marriage.
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George Finlay Simmons (b. 1925 )
American mathematician who has worked in topology and classical analysis.
Renowned for both his teaching abilities and his first-class text books.
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Robert Duncan Luce (b. 1925 )
American mathematician known for his work in game theory and economics.
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George Leitmann (b. 1925 )
American control theorist considered one of the leading authorities in optimal control theory and its applications.
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Harold William Kuhn (1925 – 2014)
American mathematician who studied game theory.
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Ernest Tilden Parker (1926 – 1991)
American mathematician best known for disproving Euler's Conjecture on Orthogonal Latin Squares with Sharadchandra Shankar Shrikhande and Raj Chandra Bose.
show full page
Donald John Lewis (1926 – 2015)
American mathematician specializing in number theory.
show full page
Martin Shubik (b. 1926 )
American economist, who is Professor Emeritus of Mathematical Institutional Economics at Yale University.
show full page
Robert Lawson Vaught (1926 – 2002)
American mathematician who mainly worked in mathematical logic, and was one of the founders of model theory.
show full page
Hilary Whitehall Putnam (1926 – 2016)
American mathematician and philosopher, who has written significantly on various subjects, such as the philosophy of logic and language acquisition.
show full page
Richard C. Jeffrey (1926 – 2002)
American mathematician who mainly worked in logic and probability theory.
show full page
Nesmith Cornett Ankeny (1927 – 1993)
American mathematician specialising in number theory.
show full page
Robert Gardner Bartle (1927 – 2003)
American mathematician specializing in real analysis.
Best known for his text books.
show full page
Reuben Hersh (b. 1927 )
American mathematician best known for his writings on the philosophy of mathematics.
show full page
Richard S. Pierce (1927 – 1992)
American mathematician who mainly worked in abstract algebra.
show full page
John Lewis Selfridge (1927 – 2010)
American mathematician who contributed to the fields of analytic number theory, computational number theory and combinatorics.
Proved in $1962$ that $78 \ 557$ is a Sierpiński number of the second kind.
Conjectured (with Wacław Franciszek Sierpiński) that it is also the smallest. This still has not been proven (see Sierpiński Problem).
show full page
Joseph Steven Madachy (1927 – 2014)
American research chemist, technical editor and recreational mathematician.
show full page
Benjamin Franklin Logan (1927 – 2015)
American electrical engineer and bluegrass music fiddler.
Corresponded with Donald E. Knuth, with whom he exchanged insights.
show full page
Wendell Helms Fleming (b. 1928 )
American mathematician specializing in geometrical analysis and stochastic differential equations.
show full page
Harold Seymour Shapiro (b. 1928 )
American mathematician best known for inventing the Shapiro polynomials and for pioneering work on quadrature domains.
show full page
Abner Shimony (1928 – 2015)
American physicist and philosopher of science specializing in quantum theory.
show full page
Joseph Bernard Kruskal (b. 1928 )
Joseph Bernard Kruskal, Jr. is an American mathematician working in the fields of statistics, computer science and graph theory, among others.
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Ray Alden Kunze (1928 – 2014)
American mathematician whose research concerned the representation theory of groups and noncommutative harmonic analysis.
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Martin David Davis (b. 1928 )
American mathematician working mainly in the field of mathematical logic.
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Thomas Andrew Lehrer (b. 1928 )
Tom Lehrer was a mathematics lecturer at the University of California, Santa Cruz.
Far better known for his brief but successful musical career.
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John Forbes Nash (1928 – 2015)
American mathematician who made fundamental contributions to game theory, differential geometry, and the study of partial differential equations
show full page
Louis Auslander (1928 – 1997)
Prolific American mathematician who worked in many fields, including Finsler geometry, geometry of solvmanifolds and nilmanifolds, locally affine spaces, many aspects of harmonic analysis, representation theory of solvable Lie groups, and multidimensional Fourier transforms and the design of signal sets for communications and radar.
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Harvey Alan Dubner (b. 1928 )
American engineer and mathematician specializing in the mathematics of casino games and finding large primes.
Invented the point-count method for gaining an advantage in blackjack.
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James Harold McKay (b. 1928 )
American mathematician best known for his work in group theory.
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Henry W. Gould (b. 1928 )
American mathematician whose research has been in combinatorial analysis, number theory, special functions of mathematical physics, and the history of mathematics and astronomy.
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Halsey Lawrence Royden (1928 – 1993)
American mathematician specialising in complex analysis, Riemann surfaces and differential geometry.
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Donald G. Higman (1928 – 2006)
American mathematician noted for his discovery of the Higman-Sims Group, with Charles C. Sims.
His work contributed towards the discovery of several of the sporadic simple groups.
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Barry Mitchell (b. 1930 )
American mathematician who has worked influentially in category theory.
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Donald J. Newman (1930 – 2007)
American mathematician active in the fields of Complex Analysis, Number Theory and Approximation Theory.
Best known for his elementary proof of the Prime Number Theorem.
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James Raymond Munkres (b. 1930 )
American mathematician and author of Topology, one of the most popular undergraduate topology textbooks.
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Richard Merett Montague (1930 – 1971)
American mathematician and logician.
Proved that ZFC must contain infintely many axioms.
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John Rolfe Isbell (1930 – 2005)
American mathematician best known for his work in topology and category theory.
Also published under the pseudonyms John Rainwater, M.G. Stanley and H.C. Enos.
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Norman Woodason Johnson (b. 1930 )
American mathematician best known for enumerating all $92$ convex non-uniform polyhedra with regular faces.
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John David Brillhart (b. 1930 )
American mathematician known for his work in integer factorization, including the development of the continued fraction factorization method.
Has been a principal participant in the Cunningham project.
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1931 and onwards
Kenneth Myron Hoffman (c. 1931 – 2008)
American mathematician whose primary area of research specialization was functional analysis.
show full page
Daniel Leonid Slotnick (1931 – 1985)
American mathematician and computer architect who pioneered the concept of parallelism in computer architectures.
Chief architect of the Illiac IV supercomputer.
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John Winsor Pratt (b. 1931 )
American mathematician who has made contributions to research in risk aversion theory.
show full page
Herbert Saul Wilf (b. 1931 )
American mathematician who specializes in combinatorics and graph theory.
show full page
John Willard Milnor (b. 1931 )
American mathematician best known for his work in differential topology.
show full page
Rudolph Michael Najar (b. 1931 )
American mathematician with a research interest in elementary number theory.
show full page
Basil Gordon (1931 – 2012)
American mathematician specializing in number theory and combinatorics.
Worked with Wernher von Braun on the US's contribution to the Space Race.
show full page
Joseph F. Stephany (1932 – 2011)
American research scientist, and amateur chess player and mathematician.
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Harry Lewis Nelson (b. 1932 )
American mathematician and computer programmer.
Member of the team that won the World Computer Chess Championship in $1983$ and $1986$.
Co-discoverer with David Slowinski of the $27$th Mersenne prime $2^{44 \, 497} − 1$ in $1979$.
Editor of the Journal of Recreational Mathematics for five years.
show full page
David Abram Antin (1932 – 2016)
American poet, critic and performance artist, who also translated various scientific and mathematical works.
show full page
Solomon Wolf Golomb (1932 – 2016)
American mathematician, engineer and professor of electrical engineering at the University of Southern California, best known for his works on mathematical games.
Invented Cheskers in $1948$ and coined the name.
Fully described polyominoes and pentominoes in $1953$
Specialized in problems of combinatorial analysis, number theory, coding theory and communications.
His game of Pentomino inspired Tetris.
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Kenneth Ira Appel (1932 – 2013)
American mathematician who in 1976, along with Wolfgang Haken, proved the Four Color Theorem with the help of a computer.
show full page
Dana Stewart Scott (b. 1932 )
American computer scientist, logician and philosopher.
show full page
Theodore William Gamelin (b. 1933 )
American mathematician who majors in analysis.
show full page
Nils John Nilsson (b. 1933 )
American mathematician who was one of the founders in the field of artificial intelligence.
show full page
Stephen Hoel Schanuel (1933 – 2014)
American mathematician working in the fields of abstract algebra and category theory, number theory, and measure theory.
Known for Schanuel's Conjecture.
show full page
Paul Joseph Cohen (1934 – 2007)
American mathematician working in logic and set theory.
Best known for his work on the Continuum Hypothesis.
show full page
Robert B. Ash (1935 – 2015)
American mathematician working in various areas, including Information Theory and Discrete Mathematics
show full page
Ronald Lewis Graham (b. 1935 )
American mathematician famous for his work in the field of Ramsey theory.
Notable for introducing Graham's number, the largest number ever yet encountered in mathematics.
Popularized the concept of the Erdős number.
Husband of Fan Chung Graham, friend and colleague of Paul Erdős.
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Herbert Bruce Enderton (1936 – 2010)
American mathematician best known for his textbooks in mathematical logic and set theory.
Also a popular educational contributor to various usenet groups.
show full page
Peter C. Fishburn (b. 1936 )
American statistician known as a pioneer in the field of decision-making processes.
show full page
Howard E. Sturgis (1936 – 1990)
American mathematician and computer scientist.
Co-designer (with John C. Shepherdson) of the Unlimited Register Machine, a refinement of the Turing machine.
show full page
Peter John Freyd (b. 1936 )
American mathematician known for work in category theory.
show full page
Thomas William Hungerford (1936 – 2014)
American mathematician working in algebra and mathematics education.
show full page
Robert W Floyd (1936 – 2001)
American computer scientist, who was active in discrete mathematics.
Noted for his work on parsing.
Introduced the concept of error diffusion for rendering images.
Pioneered the field of program verification using logical assertions. This contributed to what later became Hoare logic.
show full page
Gary Theodore Chartrand (b. 1936 )
American mathematician who specializes in graph theory.
He is known for his textbooks on introductory graph theory and for the concept of a highly irregular graph.
show full page
Howard Jerome Keisler (b. 1936 )
American mathematician whose research has included model theory and non-standard analysis.
show full page
Peter Bruce Andrews (b. 1937 )
American mathematician best known for creating the TPS automated theorem prover.
show full page
Underwood Dudley (b. 1937 )
American mathematician best known for his popular writing.
show full page
James Burton Ax (1937 – 2006)
American mathematician who proved several results in algebra and number theory by using model theory.
show full page
Robert Butler Wilson (b. 1937 )
American economist known for his contributions to management science and business economics.
show full page
William Robert Alford (1937 – 2003)
American mathematician who worked in the field of number theory.
show full page
Alexander Hurwitz (b. 1937 )
American mathematician who found the $19$th and $20$th Mersenne primes $2^{4253} - 1$ and $2^{4423} - 1$ in $1961$.
show full page
Barry Charles Mazur (b. 1937 )
American mathematician who has worked in geometric topology and arithmetic topology.
show full page
Robert Berger (b. 1938 )
American mathematician known for devising the first aperiodic tiling, using a set of $20 \ 426$ distinct tile shapes.
show full page
Ian Mueller (1938 – 2010)
American scholar of ancient Greek philosophy of science and the reception of Plato and Aristotle in late antiquity.
show full page
J. Arthur Seebach (1938 – 1996)
J. Arthur Seebach, Jr. was an American mathematician best known for the groundbreaking Counterexamples in Topology which he co-authored with Lynn Arthur Steen, "... a counterexample to the view, widespread at the time, that undergraduates could neither do nor even contribute to research in mathematics."[1].
An early advocate for introducing computers into the educational curriculum.
show full page
Charles Coffin Sims (b. 1938 )
American mathematician active in the field of group theory.
With Donald G. Higman, discovered the Higman-Sims Group.
Developed software leading up to the discovery of the Lyons Group (also known as Lyons-Sims Group) and O'Nan Group (also known as O'Nan-Sims Group).
show full page
Donald Ervin Knuth (b. 1938 )
Pronounced K-Nooth.
Hugely influential American computer scientist famous for his multi-volume The Art of Computer Programming, still famously a work in progress.
The "father of analysis of algorithms".
Pioneered research and design of the representation of mathematics via computer.[2] Author of Computers and Typesetting, another multi-volume work.
show full page
Richard Mansfield Dudley (b. 1938 )
American mathematician whose main fields of study are real analysis and probability theory.
show full page
George Eyre Andrews (b. 1938 )
American mathematician best known for his work in number theory.
Famous for discovering Srīnivāsa Aiyangār Rāmānujan's Lost Notebook in 1976.
show full page
Lorraine Lois Foster (b. 1938 )
American mathematician working in number theory and the theory of mathematical symmetry.
First woman to receive a Ph.D. in mathematics from California Institute of Technology.
show full page
John Bligh Conway (b. 1939 )
American mathematician best known for his comprehensive books on functional and complex analysis.
show full page
David Breyer Singmaster (b. 1939 )
American mathematician best known for his work in the field of recreational mathematics, in particular Rubik's cube.
show full page
Stephen Arthur Cook (b. 1939 )
American mathematician and computer scientist who has made considerable progress in the field of complexity theory.
show full page
Charles Chapman Pugh (b. 1940 )
American mathematician who specializes in dynamic systems.
show full page
Alexander G. Ramm (b. 1940 )
Russian-born American mathematician who specializes in differential and integral equations, operator theory, ill-posed and inverse problems, scattering theory, functional analysis, spectral theory, numerical analysis, theoretical electrical engineering, signal estimation, and tomography.
show full page
Michael David Spivak (b. 1940 )
American mathematician specializing in differential geometry.
Also noted for his textbooks.
show full page
Daniel Gray Quillen (1940 – 2011)
American mathematician mainly working in the field of algebraic topology.
show full page
George Stephen Boolos (1940 – 1996)
American philosopher who also worked in the field of mathematical logic.
show full page
Elwyn Ralph Berlekamp (b. 1940 )
American mathematician and computer scientist famous for his contributions towards game theory.
Also the innovator of several computer algorithms.
show full page
David Anthony Klarner (1940 – 1999)
American mathematician, author, and educator.
Known for his work in combinatorial enumeration, polyominoes and box-packing.
show full page
Lynn Arthur Steen (1941 – 2015)
American mathematician best known for the groundbreaking Counterexamples in Topology which he co-authored with J. Arthur Seebach, Jr..
show full page
Joel William Robbin (b. 1941 )
American mathematician specialising in mathematical logic and matrix algebra.
show full page
Roland Edwin Larson (b. 1941 )
Roland Edwin ("Ron") Larson is an American professor of mathematics, best known for the widely-used books (covering all levels from from pre-school to college) written by him, often in collaboration.
show full page
Robert James McEliece (b. 1942 )
American mathematician and engineering professor best known for his work in information theory.
show full page
Joseph Anthony Gallian (b. 1942 )
American mathematician who has been awarded for the quality of his teaching.
show full page
Melvin Fitting (b. 1942 )
American mathematician specialising in logic.
show full page
Alfred S. Posamentier (b. 1942 )
American educator, writer and commentator on American mathematics and science education.
show full page
Robert Everist Greene (b. 1943 )
American mathematician whose main area of work is in differential geometry.
show full page
Ralph William Gosper, Jr. (b. 1943 )
American mathematician and pioneering computer programmer.
Considered by some to be one of the founders of the hacker community.
show full page
George Mark Bergman (b. 1943 )
American mathematician whose primary research area is algebra, in particular associative rings, universal algebra, category theory and the construction of counterexamples.
Mathematical logic is an additional research area.
show full page
Herbert Kenneth Kunen (b. 1943 )
American mathematician, better known as Kenneth Kunen, working in set theory.
show full page
Nicholas Michael Katz (b. 1943 )
American mathematician working in the fields of algebraic geometry, particularly on p-adic methods, monodromy and moduli problems, and number theory.
show full page
Carl Bernard Pomerance (b. 1944 )
American mathematician specialising in number theory.
show full page
Vaughan Ronald Pratt (b. 1944 )
American mathematician specialising in computer science.
show full page
Bailey Whitfield Diffie (b. 1944 )
American mathematician and cryptographer.
One of the pioneers of public-key cryptography
Inventor with Martin Edward Hellman of the trapdoor function.
show full page
Hugh Lowell Montgomery (b. 1944 )
American mathematician best known for his work in analytic number theory and mathematical analysis.
show full page
Melvyn Bernard Nathanson (b. 1944 )
American mathematician specialising in, particularly additive and combinatorial, number theory.
show full page
Mitchell Jay Feigenbaum (b. 1944 )
American mathematical physicist whose pioneering studies in chaos theory led to the discovery of the Feigenbaum constants.
show full page
Robert Louis Griess, Jr. (b. 1945 )
American mathematician working on finite simple groups and vertex algebras.
Constructed the Fischer-Griess Monster using the Griess algebra.
show full page
Edward M. Reingold (b. 1945 )
American computer scientist active in the fields of algorithms, data structures, graph drawing, and calendrical calculations.
show full page
Persi Warren Diaconis (b. 1945 )
American mathematician and former professional magician of Greek descent, best known for tackling mathematical problems involving randomness and randomization, such as coin flipping and shuffling playing cards.
show full page
Douglas Richard Hofstadter (b. 1945 )
American mathematician and philosopher most noted for the books he has written.
In particular, famous for being the author of Gödel, Escher, Bach: an Eternal Golden Braid.
Between 1981 and 1983, he took over from Martin Gardner the task of writing the Mathematical Games column in Scientific American, which he renamed to Metamagical Themas.
show full page
Samuel Standfield Wagstaff Jr. (b. 1945 )
American mathematician and computer scientist, whose research interests are in the areas of cryptography, parallel computation, and analysis of algorithms, especially number theoretic algorithms.
show full page
Martin Golubitsky (b. 1945 )
Marty Golubitsky is an American mathematician specialising in mathematical biosciences.
show full page
Martin Edward Hellman (b. 1945 )
American mathematician and cryptographer.
One of the pioneers of public-key cryptography
Inventor with Bailey Whitfield Diffie and Ralph C. Merkle of the technique of public key cryptography.
show full page
Leonard Max Adleman (b. 1945 )
American cryptographer and software engineer, best known for his involvement in the creation of the RSA algorithm.
Successfully used DNA as a computation technique.
Supposed to have coined the term virus in the context of computer programs.
show full page
Derek A. Zave (1946 – 1987)
American computer scientist who has done research into power series with harmonic numbers.
show full page
Rudolf von Bitter Rucker (b. 1946 )
Rudy Rucker is an American mathematician, computer scientist, science fiction author and philosopher.
Best known (in the field of mathematics) for his work Infinity and the Mind.
show full page
William Paul Thurston (1946 – 2012)
American mathematician who specialised in low-dimensional topology.
Won the Fields Medal in 1982 for his work on $3$-manifolds.
show full page
Ronald Linn Rivest (b. 1947 )
American cryptographer and software engineer, best known for his involvement in the creation of the RSA algorithm.
Also well-known for being one of the contributors to 1990: Thomas H. CormenCharles E. Leiserson and Ronald L. Rivest: Introduction to Algorithms.
show full page
Gerald Budge Folland (b. 1947 )
American mathematician whose areas of interest are harmonic analysis (on both Euclidean space and Lie groups), differential equations, and mathematical physics.
show full page
Peter Lawrence Montgomery (b. 1947 )
American mathematician whose specialty is cryptography.
show full page
William Wade Dunham (b. 1947 )
American mathematician specialising in topology.
Later became interested in the history of mathematics, particularly that concerning Leonhard Euler.
show full page
Richard E. Crandall (1947 – 2012)
American physicist and computer scientist who made contributions to computational number theory.
show full page
Michael R. Genesereth (b. 1948 )
American professor of computer science.
show full page
Richard Schroeppel (b. 1948 )
American mathematician whose research has included magic squares, elliptic curves and cryptography..
show full page
Paul Robert Milgrom (b. 1948 )
American economist who is also an expert in game theory, specifically auction theory and pricing strategies.
Co-creator of the No-Trade Theorem with Nancy Stokey.
show full page
David Harold Bailey (b. 1948 )
American mathematician and computer scientist best known as the co-creator (with Peter Benjamin Borwein and Simon Plouffe) of the BBP Algorithm.
show full page
Lee Vernon Stiff (b. 1949 )
American mathematician working mainly in the field of mathematics education research.
Author and co-author of several mathematics textbooks.
show full page
Lawrence Craig Evans (b. 1949 )
American mathematician whose research is in the field of nonlinear partial differential equations, primarily elliptic equations.
show full page
David Marc Kreps (b. 1950 )
American game theorist and economist, known for his analysis of dynamic choice models and non-cooperative game theory, particularly the idea of sequential equilibrium.
show full page
Eric Stark Maskin (b. 1950 )
American economist who introduced the discipline of mechanism design theory.
show full page
Lawrence Clinton Washington (b. 1951 )
American mathematician specializing in number theory.
show full page
Steven George Krantz (b. 1951 )
American mathematician best known for his writing and teaching.
show full page
Roger Bruce Myerson (b. 1951 )
American economist and political scientist.
Also active in the fields of game theory and mechanism design.
show full page
Robert Scott Rumely (b. 1952 )
American professor of mathematics specializing in number theory and arithmetic geometry.
He is one of the inventors of the Adleman-Pomerance-Rumely Primality Test.
show full page
Charles Eric Leiserson (b. 1953 )
American computer scientist, specializing in the theory of parallel computing and distributed computing.
Best known as the co-author of Introduction to Algorithms, along with Thomas H. Cormen, Ronald L. Rivest and Cliff Stein.
show full page
Glenn H. Stevens (b. 1953 )
American mathematician and educator, whose research specialties are number theory, automorphic forms, and arithmetic geometry.
show full page
Oren Patashnik (b. 1954 )
American computer scientist best known for co-authoring Concrete Mathematics: A Foundation for Computer Science with Ronald L. Graham and Donald E. Knuth.
show full page
Michael Keith (b. 1955 )
American mathematician and software engineer, best known in the mathematical community for his work in the field of recreational mathematics.
Also known as the author of works of constrained writing.
show full page
David Knudsen Levine (b. 1955 )
American economist working in game theory.
show full page
Joseph Hillel Silverman (b. 1955 )
American mathematician whose work has been in number theory, arithmetic geometry, arithmetic dynamics and cryptography.
show full page
David Allen Bayer (b. 1955 )
American mathematician known for his contributions in algebra and symbolic computation and for his consulting work in the movie industry.
show full page
Thomas H. Cormen (b. 1956 )
American mathematician and computer scientist, best known for being the co-author of Introduction to Algorithms, along with Charles E. Leiserson, Ronald L. Rivest and Cliff Stein.
show full page
Paul Hoffman (b. 1956 )
American author, science educator, food entrepreneur and occasional writer on mathematics.
Also a puzzlemaster under the pseudonym Dr. Crypton.
show full page
American mathematician, humorist and prolific writer active in knot theory and topology.
Active in combating the too-common psychological condition of math anxiety.
show full page
Drew Fudenberg (b. 1957 )
American mathematician working on game theory, including equilibrium theory, learning in games, and evolutionary game theory.
show full page
Clifford Alan Pickover (b. 1957 )
American mathematician whose main research area is fractals.
Also a prolific popular writer on several topics.
show full page
George F. Woltman (b. 1957 )
American mathematician and computer scientist who is the founder of the Great Internet Mersenne Prime Search (GIMPS).
show full page
Mark Steven Manasse (b. 1958 )
American computer scientist and mathematician who works in the field of algorithmic number theory
Part of the team which factorised the $9$th Fermat number.
show full page
Ariel T. Glenn (b. 1960 )
American mathematician and software engineer best noted for finding the Mersenne prime $M_{21 \, 701}$, alongside Landon Curt Noll, while still at high school.
show full page
Landon Curt Noll (b. 1960 )
American mathematician best noted for finding the two Mersenne primes $M_{21\ 701}$ and $M_{23\ 209}$ while still at high school (the first together with Laura Ariel Nickel, now Ariel T. Glenn).
show full page
Kenneth Keeler (b. 1961 )
Kenneth "Ken" Keeler is an American mathematician who passes the time between theorems writing episodes of Futurama.
The Futurama episode The Prisoner of Benda features an application of what we on $\mathsf{Pr} \infty \mathsf{fWiki}$ are going to call the Futurama Theorem. Who said permutation theory was boring?
show full page
John Carlos Baez (b. 1961 )
American mathematician and physicist known for his work in spin foams in loop quantum gravity.
Also known for his writings on octonions and higher-order Clifford algebras.
show full page
Clifford Seth Stein (b. 1965 )
American computer scientist and professor of industrial engineering and operations research.
Well-known as one of the contributors to later editions of Introduction to Algorithms, along with Thomas H. Cormen, Charles E. Leiserson and Ronald L. Rivest .
show full page
Noam David Elkies (b. 1966 )
American mathematician and chess master.
With Arthur Oliver Lonsdale Atkin, extended Schoof's Algorithm to create the Schoof-Elkies-Atkin Algorithm.
Found the first known counterexample to Euler's Quartic Conjecture.
show full page
Jordan Stuart Ellenberg (b. 1971 )
American mathematician working mainly within arithmetic geometry.
show full page
Danica Mae McKellar (b. 1975 )
American mathematician better known as an actor.
Also known for her books aimed specifically at middle-school and high-school girls to increase their confidence in mathematics.
show full page
Nathaniel Read Silver (b. 1978 )
American statistician and writer who analyzes baseball and elections.
Famous for successfully calling the outcomes in 49 of the 50 states in the 2008 U.S. Presidential election.
show full page
Victoria Hart (b. 1988 )
American mathematician best known for the videos she has published on YouTube under the name Vi Hart.
show full page
References
1. It is impossible accurately to assess the impact of $\TeX$ on the ability to communicate mathematics via computer. This website would not have been possible without it. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7100818157196045, "perplexity": 9555.630593134378}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221213794.40/warc/CC-MAIN-20180818213032-20180818233032-00182.warc.gz"} |
https://fr.maplesoft.com/support/help/Maple/view.aspx?path=QuantumChemistry/CorrelationEnergy | CorrelationEnergy - Maple Help
Home : Support : Online Help : Toolboxes : Quantum Chemistry : CorrelationEnergy
QuantumChemistry
CorrelationEnergy
compute the correlation energy
Calling Sequence CorrelationEnergy(molecule, method, options)
Parameters
molecule - list of lists; each list has 4 elements, the string of an atom's symbol and atom's x, y, and z coordinates method - (optional) method = name/procedure where name is one of 'HartreeFock' (default), 'DensityFunctional', options - (optional) equation(s) of the form option = value where option is any valid option of the chosen method
Description
• CorrelationEnergy computes the correlation energy, the difference between the exact energy and Hartree-Fock energy.
• The procedure returns the correlation energy as a float.
• The default method is 'HartreeFock' method whose correlation energy is 0.
• The result depends upon the chosen molecule, method, and basis set among other options such as charge, spin, and symmetry.
• Because the methods employ Maple cache tables, the procedure only computes the correlation energy if it has not been previously computed by calling the method directly or indirectly through another property.
Examples
> $\mathrm{with}\left(\mathrm{QuantumChemistry}\right):$
Computation of the correlation energy of the molecule with the MP2 method
>
${\mathrm{molecule}}{≔}\left[\left[{"H"}{,}{0}{,}{0}{,}{0}\right]{,}\left[{"F"}{,}{0}{,}{0}{,}{0.95000000}\right]\right]$ (1)
>
${\mathrm{output_hf}}{≔}{0.}$ (2)
>
${\mathrm{output_hf}}{≔}{-0.01882706}$ (3)
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https://www.machinelearningfreaks.com/label-noise-in-segmentation-networks-mitigation-must-deal-with-bias-arxiv2107-02189v1-cs-cv/ | # Label noise in segmentation networks : mitigation must deal with bias. (arXiv:2107.02189v1 [cs.CV])
Imperfect labels limit the quality of predictions learned by deep neural
networks. This is particularly relevant in medical image segmentation, where
reference annotations are difficult to collect and vary significantly even
across expert annotators. Prior work on mitigating label noise focused on
simple models of mostly uniform noise. In this work, we explore biased and
unbiased errors artificially introduced to brain tumour annotations on MRI
data. We found that supervised and semi-supervised segmentation methods are
robust or fairly robust to unbiased errors but sensitive to biased errors. It
is therefore important to identify the sorts of errors expected in medical
image labels and especially mitigate the biased errors. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.808459460735321, "perplexity": 6658.806737069588}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103036099.6/warc/CC-MAIN-20220625190306-20220625220306-00353.warc.gz"} |
https://kampro.nazwa.pl/overnight-spot-xjquz/probability-corbett-maths-b6b824 | probability corbett maths
Corbett Maths. = p^2 (1-p)\)In a similar way we get$$P (H T H) = p \cdot (1-p) \cdot p = p^2 (1-p)$$$$P (T H H) = (1-p) \cdot p \cdot p = p^2 (1-p)$$$$P( E ) = P ( \; (H H T) \; or \; (H T H) \; or \; (T H H) \;)$$Use the sum rule knowing that $$(H H T) , (H T H)$$ and $$(T H H)$$ are mutually exclusive$$P( E ) = P( (H H T) + P(H T H) + P(T H H) )$$Substitute$$P( E ) = p^2 (1-p) + p^2 (1-p) + p^2 (1-p) = 3 p^2 (1-p)$$All elements in the set $$E$$ are equally likely with probability $$p^2 (1-p)$$ and the factor $$3$$ comes from the number of ways 2 heads $$(H)$$ are within 3 trials and that is given by the formula for combinations written as follows:$$3 = \displaystyle {3\choose 2}$$$$P(E)$$ may be written as$$\displaystyle {P(E) = {3\choose 2} p^2 (1-p)^1 = {3\choose 2} p^2 (1-p)^1 = {3\choose 2} p^2 (1-p)^{3-2}}$$Hence, the general formula for binomial probabilities is given by Each question has five possible answers with one correct answer per question. However, if you purchase the entire pack (281 lessons) please contact me and I will get an editable version to you on promethean. arrow_back Back to Probability with Venn Diagrams Probability with Venn Diagrams: Videos. We would like to show you a description here but the site won’t allow us. P29 Venn Diagrams â Terminology This website and its content is subject to our Terms and Conditions. Share: Share on Facebook Share on Twitter Share on Linkedin Share on Google Share by email. The best way to explain the formula for the binomial distribution is to solve the following example. The Corbettmaths Textbook Exercise on Conditional Probability. Week 26 - (20 April 2020) Algebra. I have created 281 lesson presentations that cover the complete KS3 and KS4 Maths course including all new topics for the new 9-1 GCSE spec. Arrange these distances in order, from shortest to longest 6.077m 6.31m 6.19m 6.4m 6.009m 631m C ooqm (0 071m 4. At the end of each presentation there are summary questions with answers attached. Here is the Transum version of this now famous Maths exam question: Hannah has 6 orange sweets and some yellow sweets. Because the card is replaced back, it is a binomial experiment with the number of trials $$n = 10$$There are 26 red card in a deck of 52. Venn diagrams and probability. Probability is the maths of chance. Student Assessment Sheets. Week 26 - (20 April 2020) Algebra. Store. Key Words List by Unit. A selection of top quality videos, from the best of the web, to aid the teaching and learning of this topic. Mathster; Corbett Maths (2) © CORBETTMATHS 2014 "The teacher selects two students at random to go on a trip. Binomial Probability Distribution Calculator. P25 Probability Of An Event Not Happening A card is drawn from a deck of 52 cards at random, its color noted and then replaced back into the deck, 10 times. The probability of her taking 2 orange sweets is $$\frac13$$. It really is one of the very best websites around. What is the probability that a student will answer 15 or more questions correct (to pass) by guessing randomly?. This is the same for all topics eg, Algebra will cost £10 for all lessons. From the weather, to the national lottery, with dice-throwing in between, the two discuss teaching probability and common pitfalls...– Ouça o Maths Appeal Ep 8 - Probability / Simon Singh de Maths Appeal instantaneamente no seu tablet, telefone ou navegador - sem fazer qualquer download. Understand that the probabilities of all possible outcomes sum to 1 Corbett Maths. The probability of something which is certain to happen is 1. Created: Aug 22, 2018| Updated: Aug 25, 2020, ALL 281 Lessons for £20. A multiple choice test has 20 questions. 2.!Two fair six sided dice are rolled. How to tell your life story in your college application essays. come with answers. P16 Stem and Leaf Diagram Mathster; Corbett Maths Addition Video 1 Questions Answers Angles: Facts Video 2 Questions Answers Angles: Measuring/Drawing Video 3 Questions Answers Angles in Polygons Video 4 Questions Answers Angles in Quadrilaterals Video 5 Questions Answers Angles: Triangles Video 6 Questions … Teachit Maths - Drawing Pin Probability Experiment ♥ (2) Student carry out an experiment in which they calculate the experimental probability of the pin landing 'pin up' or 'pin down'. Videos, worksheets, 5-a-day and much more Algebra: 81 lessons Corbettmaths - This video explains how to answer conditional probability questions. The Corbettmaths Textbook Exercise on Probability. By continuing to browse our site you are agreeing to our use of cookies. P33 Probability Tree Diagrams â Conditional GCSE Maths - Formula Poster. A powerpoint introduction to Probability. My name is Billy, a maths teachers working in the North West of the UK. P28 Venn Diagrams â Introduction Week 25 - (30 March 2020) Numbers. Probability is about estimating or calculating how likely or probable something is to happen. P17 Averages And Range Problem Solve We write P (heads) = ½ . Geometry and Measure: 65 lessons How to - do Simple Probability with number lines. And best of all they all (well, most!) 1. = \dfrac{1 \times 2 \times 3 \times 4 \times 5}{(1 \times 2 \times 3)(1 \times 2)} = 10 \)Substitute$$P(3 \; \text{heads in 5 trials}) = 10 (0.5)^3 (0.5)^{2} = 0.3125$$, eval(ez_write_tag([[728,90],'analyzemath_com-large-mobile-banner-1','ezslot_10',700,'0','0']));Example 3A fair die is rolled 7 times, find the probability of getting "$$6$$ dots" exactly 5 times.Solution to Example 3This is an example where although the outcomes are more than 2, we interested in only 2: "6" or "no 6".The die is rolled 7 times, hence the number of trials is $$n = 7$$.In a single trial, the outcome of a "6" has probability $$p = 1/6$$ and an outcome of "no 6" has a probability $$1 - p = 1 - 1/6 = 5/6$$The probability of having 5 "6" in 7 trials is given by the formula for binomial probabilities above with $$n = 7$$, $$k = 5$$ and $$p = 1/6$$$$\displaystyle P(5 \; \text{heads in 7 trials}) = \displaystyle {7\choose 5} (1/6)^5 (1-5/6)^{7-5} \\ = \displaystyle {7\choose 5} (1/6)^5 (5/6)^{2}$$Use formula for combinations to calculate$$\displaystyle {7\choose 5} = \dfrac{7!}{5!(7-5)!} Tes Global Ltd is This video is a guide to probability. Calculate experimental probabilities/relative frequencies and estimate the most likely count given the number of trials and a probability. (a) Complete the tree diagram Late 0.4 Rain 0.3 On Time Late 0.15 No Rain On Time (2) (b) Work out the number of … More. P30 Frequency Treeâs Corbett Maths offers outstanding, original exam style questions on any topic, as well as videos, past papers and 5-a-day. (a) Complete the table to show all possible scores. eval(ez_write_tag([[300,250],'analyzemath_com-medrectangle-4','ezslot_4',342,'0','0']));The best way to explain the formula for the binomial distribution is to solve the following example. ANOVA 1: Calculating SST (total sum of squares) | Probability and Statistics | Khan Academy. P13 Scattergraphs - Line of Best Fit P11 Pie Chartsâ¦Interpret The probability of something which is impossible to happen is 0. Therefore the probability of getting a correct answer in one trial is \( p = 1/5 = 0.2$$It is a binomial experiment with $$n = 20$$ and $$p = 0.2$$.$$P(\text{student answers 15 or more}) = P( \text{student answers 15 or 16 or 17 or 18 or 19 or 20}) \\ = P(15) + P(16) + P(17) + P(18) + P(19) + P(20)$$Using the binomial probability formula$$P(\text{student answers 15 or more}) = \displaystyle{20\choose 15} 0.2^{15} (1-0.2)^{20-15} + {20\choose 16} 0.2^{16} (1-0.2)^{20-16} \\ \quad\quad\quad\quad\quad + \displaystyle {20\choose 17} 0.2^{17} (1-0.2)^{20-17} + {20\choose 18} 0.2^{18} (1-0.2)^{20-18} \\ \quad\quad\quad\quad\quad + \displaystyle {20\choose 19} 0.2^{19} (1-0.2)^{20-19} + {20\choose 20} 0.2^{20} (1-0.2)^{20-20}$$$$\quad\quad\quad\quad\quad \approx 0$$Conclusion: Answering questions randomly by guessing gives no chance at all in passing a test. We explain what probability / chance / likelihood means, how children are taught about probability from Year 5 and the kinds of mathematical problems involving probability … Guestbook. On the day after one GCSE paper Twitter and the media were buzzing with comments about a particular question about Hannah's sweets. P5 Dual Bar Charts GCSE Maths (9-1) Revision Advice. P23 Probability and Listing Outcomes If it rains, the probability of a bus being late is 0.4. Each question has 5 possible answers with one correct. = 1 \times 2 \times 3 \times ..... \times (n - 1) \times n \) , is read as $$n$$ factorial. Get them in one power point. Welcome to Corbettmaths! If there are topics missing from the list above that you would like to see included, please use the contact form below to let us know. P1 Discrete and Continuous Data Download the medium term plan by clicking on the button above. "at least 8 of them have a home insurance with "MyInsurance" means 8 or 9 or 10 have a home insurance with "MyInsurance"The probability that at least 8 out of 10 have have home insurance with the "MyInsurance" is given by$$P( \text{at least 8}) = P( \text{8 or 9 or 10})$$Use the addition rule$$= P(8)+ P(9) + P(10)$$Use binomial probability formula calling "have a home insurance with "MyInsurance" as a "success".$$= P(8 \; \text{successes in 10 trials}) + P(9 \; \text{successes in 10 trials}) + P(10 \; \text{successes in 10 trials})$$$$= \displaystyle{10\choose 8} \cdot 0.8^8 \cdot (1-0.8)^{10-8} + \displaystyle{10\choose 9} \cdot 0.8^9 \cdot (1-0.8)^{10-9} + \displaystyle{10\choose 10} \cdot 0.8^10 \cdot (1-0.8)^{10-10}$$$$= 0.30199 + 0.26843 + 0.10737 = 0.67779$$b)It is a binomial distribution problem with the number of trials is $$n = 500$$.The number of people out of the 500 expected to have a home insurance with "MyInsurance" is given by the mean of the binomial distribution with $$n = 500$$ and $$p = 0.8$$.$$\mu = n p = 500 \cdot 0.8 = 400$$400 people out of the 500 selected at random from that city are expected to have a home insurance with "MyInsurance". What is the probability that a student will answer 10 or more questions correct (to pass) by guessing randomly?NOTE: this questions is very similar to question 5 above, but here we use binomial probabilities in a real life situation that most students are familiar with.Solution to Example 6Each questions has 4 possible answers with only one correct. Corbett Maths offers outstanding, original exam style questions on any topic, as well as videos, past papers and 5-a-day. arrow_back Back to Probability with Venn Diagrams Probability with Venn Diagrams: Worksheets with Answers. arrow_back Back to Probability with Venn Diagrams Probability with Venn Diagrams: Worksheets with Answers. Corbettmaths - 304 Followers, 31 Following, 592 pins | Corbettmaths - Home to video tutorials, 5-a-day, practice questions and much more. According to an OCDE report (https://data.oecd.org/eduatt/population-with-tertiary-education.htm); for the age group between 25 and 34 years, 61.8% in Canada and 50.8% in the United Kingdom have a tertiary education. $P(k \; \text{successes in n trials}) = {n\choose k} p^k (1-p)^{n-k}$, Mean: $$\mu = n \cdot p$$ , Standard Deviation: $$\sigma = \sqrt{ n \cdot p \cdot (1-p)}$$. We use cookies to deliver functionality and provide you with a better service. Here you will find RevisionMaths.com’s key tips to help you prepare for your exams. Number of ways it can happen: 4 (there are 4 blues) Total number of outcomes: 5 (there are 5 marbles in total) So the probability = 4 5 = 0.8. This website and its content is subject to our Terms and Mathematics exam-style questions typical of A-Level, IB, GCSE(9-1) and other standardised tests. Maths Genie ¦ Corbett Maths ¦ Mr Barton Maths Takeaway ¦ Mr Barton Maths Topic Search ¦ Just Maths 13.1 Calculating Probability - Calculate simple probabilities from equally likely events arrow_back Back to Probability with Venn Diagrams Probability with Venn Diagrams: Videos. GCSE Maths - Formula Poster. Mrs B Maths. Hegerty Maths Youtube. Key Words List by Unit. Probability and Statistics: 40 lessons, Prices: ... FS Maths Level 2 Probability and Statistics. Number: 62 lessons Example 7A box contains 3 red balls, 4 white balls and 3 black balls. the probability of getting a red card in one trial is $$p = 26/52 = 1/2$$The event A = "getting at least 3 red cards" is complementary to the event B = "getting at most 2 red cards"; hence$$P(A) = 1 - P(B)$$$$P(A) = P(3)+P(4) + P(5)+P(6) + P(7)+P(8) + P(9) + P(10)$$$$P(B) = P(0) + P(1) + P(2)$$The computation of $$P(A)$$ needs much more operations compared to the calculations of $$P(B)$$, therefore it is more efficient to calculate $$P(B)$$ and use the formula for complement events: $$P(A) = 1 - P(B)$$.$$P(B) = \displaystyle {10\choose 0} 0.5^0 (1-0.5)^{10-0} + {10\choose 1} 0.5^1 (1-0.5)^{10-1} + {10\choose 2} 0.5^2 (1-0.5)^{10-2} \\ = 0.00098 + 0.00977 + 0.04395 = 0.0547$$$$P(\text{getting at least 3 red cards}) = P(A) = 1 - P(B) = 0.9453$$. A little bit of maths each day After a particularly difficult year, we need to now focus on getting our students ready for exams in the summer of 2021 despite them having a four month gap in their education at the end of year 10. What is the probability of-- so I once again, I have a deck of 52 cards, I shuffled it, randomly pick a card from that deck-- what is the probability that that card that I … Overall, she has $$n$$ sweets. Tes Global Ltd is registered in England (Company No 02017289) with its registered office … P4 Histograms and Frequency Polygons (Continuous) Lessons 7x3 click on a date button to go to that lesson. Samples of 1000 tools are selected at random and tested.a) Find the mean and give it a practical interpretation.b) Find the standard deviation of the number of tools in good working order in these samples.Solution to Example 4When a tool is selected, it is either in good working order with a probability of 0.98 or not in working order with a probability of 1 - 0.98 = 0.02.When selecting a sample of 1000 tools at random, 1000 may be considered as the number of trials in a binomial experiment and therefore we are dealing with a binomial probability problem.a) mean: $$\mu = n p = 1000 \times 0.98 = 980$$In a sample of 1000 tools, we would expect that 980 tools are in good working order .b) standard deviation: $$\sigma = \sqrt{ n \times p \times (1-p)} = \sqrt{ 1000 \times 0.98 \times (1-0.98)} = 4.43$$, Example 5Find the probability that at least 5 heads show up when a fair coin is tossed 7 times.Solution to Example 5The number of trials is $$n = 7$$.The coin being a fair one, the outcome of a head in one toss has a probability $$p = 0.5$$.Obtaining at least 5 heads; is equivalent to showing : 5, 6 or 7 heads and therefore the probability of showing at least 5 heads is given by$$P( \text{at least 5}) = P(\text{5 or 6 or 7})$$Using the addition rule with outcomes mutually exclusive, we have$$P( \text{at least 5 heads}) = P(5) + P(6) + P(7)$$where $$P(5)$$ , $$P(6)$$ and $$P(7)$$ are given by the formula for binomial probabilities with same number of trial $$n$$, same probability $$p$$ but different values of $$k$$.$$\displaystyle P( \text{at least 5 heads} ) = {7\choose 5} (0.5)^5 (1-0.5)^{7-5} + {7\choose 6} (0.5)^6 (1-0.5)^{7-6} + {7\choose 7} (0.5)^7 (1-0.5)^{7-7} \\ = 0.16406 + 0.05469 + 0.00781 = 0.22656$$. In a binomial experiment, you have a number $$n$$ of independent trials and each trial has two possible outcomes or several outcomes that may be reduced to two outcomes.The properties of a binomial experiment are:1) The number of trials $$n$$ is constant.2) Each trial has 2 outcomes (or that can be reduced to 2 outcomes) only: "success" or "failure" , "true" or "false", "head" or "tail", ...3) The probability $$p$$ of a success in each trial must be constant.4) The outcomes of the trials must be independent of each other.Examples of binomial experiments1) Toss a coin $$n = 10$$ times and get $$k = 6$$ heads (success) and $$n - k$$ tails (failure).2) Roll a die $$n = 5$$ times and get $$3$$ "6" (success) and $$n - k$$ "no 6" (failure).3) Out of $$n = 10$$ tools, where each tool has a probability $$p$$ of being "in good working order" (success), select 6 at random and get 4 "in good working order" and 2 "not in working order" (failure).4) A newly developed drug has probability $$p$$ of being effective.Select $$n$$ people who took the drug and get $$k$$ "successful treatment" (success) and $$n - k$$ "not successful treatment" (failure). ⢠All number lessons can be purchased together for £10. Probability Welcome to national5maths.co.uk A sound understanding of Probability is essential to ensure exam success. 9 students study French and German. The probability of rain in the village is 0.3. KS3 Maths Curriculum Area. P14 Introducing Sampling Methods 6 times, a ball is selected at random, the color noted and then replaced in the box.What is the probability that the red color shows at least twice?Solution to Example 7The event "the red color shows at least twice" is the complement of the event "the red color shows once or does not show"; hence using the complement probability formula, we writeP("the red color shows at least twice") = 1 - P("the red color shows at most 1") = 1 - P("the red color shows once" or "the red color does not show")Using the addition ruleP("the red color shows at least twice") = 1 - P("the red color shows once") + P("the red color does not show")Although there are more than two outcomes (3 different colors) we are interested in the red color only.The total number of balls is 10 and there are 3 red, hence each time a ball is selected, the probability of getting a red ball is $$p = 3/10 = 0.3$$ and hence we can use the formula for binomial probabilities to findP("the red color shows once") = $$\displaystyle{6\choose 1} \cdot 0.3^1 \cdot (1-0.3)^{6-1} = 0.30253$$P("the red color does not show") = $$\displaystyle{6\choose 0} \cdot 0.3^0 \cdot (1-0.3)^{6-0} = 0.11765$$P("the red color shows at least twice") = 1 - 0.11765 - 0.30253 = 0.57982. eval(ez_write_tag([[300,250],'analyzemath_com-large-mobile-banner-2','ezslot_11',701,'0','0']));Example 880% of the people in a city have a home insurance with "MyInsurance" company.a) If 10 people are selected at random from this city, what is the probability that at least 8 of them have a home insurance with "MyInsurance"?b) If 500 people are selected at random, how many are expected to have a home insurance with "MyInsurance"?Solution to Example 8a)If we assume that we select these people, at random one, at the time, the probability that a selected person to have home insurance with "MyInsurance" is 0.8.This is a binomial experiment with $$n = 10$$ and p = 0.8. Probabilities can be described in words. 20 Maths Working Wall Displays (Mostly Editable). "The probability that it is windy is 0.3 "Calculate the probability that Thomas serves an ace..... (4) 12. Probability & Statistics ⢠The entire package, all 281 lessons can be purchased for £20. Understand the difference between experimental and theoretical probabilities. A probability is a number that tells you how likely (probable) something is to happen. Conclusion. P34 (H) Interquartile Range More examples and questions on how the binomial formula is used to solve probability questions and solve problems. Mixed Attainment Maths. P2 Introducing Averages and Range = 21 \)Substitute$$P(5 \; \text{"6" in 7 trials}) = 21 (1/6)^5 (5/6)^{2} = 0.00187$$, Example 4A factory produces tools of which 98% are in good working order. The probability of something not happening is 1 minus the probability that it will happen. Solution to Example 1 When we toss a coin we can either get a head H or a tail T. We use the tree diagram including the three tosses to determine the sample space S of the experiment which is given by: S={(HHH),(HHT),(HTH),(HTT),(THH),(THT),(TTH),(TTT)} Event E of getting 2 heads out of 3 tosses is giv… P36 (H) Boxplots Probability Probability (OR Rule) Probability (Not Happening) Videos, worksheets, 5-a-day and much more (a) Complete the Venn diagram Find the probability of getting 2 heads and 1 tail. The GCSE (9-1) Maths course is very challenging for many students whichever exam board you are sitting. 8.03 - Lect 13 - Electromagnetic Waves, Solutions to Maxwell's Equations, Polarization. ⢠20 lessons are free (4 from each of the above topics) P24 Probability - Sample Space Diagrams Homework Ideas. Probability is everywhere, and Bobby and Susan are here to prove it. They have been placed in a very large single power point presentation. Total number of outcomes: 6 (there are 6 faces altogether) So the probability = 1 6. And best of all they all (well, most!) "They are in the same mathematics class, which has a total of twenty students. P40 (H) Histograms - Interpreting. c: oqq unwpst unwp6L ;usu ecsls pe10M' 01 10110,wua pseu wseŒq ou e!x-aqsq qgce (p) hon 1011 s unwpek ou su otq!usù, elx aqsq \]\( n! (2)! GCSE Probability part 1.
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https://infoscience.epfl.ch/record/129889 | Infoscience
Conference paper
# Methodology for Risk Assessment of Part Load Resonance in Francis Turbine Power Plant.
At low flow rate operation, Francis turbines feature a cavitating vortex rope in the draft tube resulting from the swirling flow of the runner outlet. The unsteady pressure field related to the precession of the vortex rope induces plane wave propagating in the entire hydraulic system. The frequency of the vortex rope precession being comprised between 0.2 and 0.4 times the turbine rotational speed, there is a risk of resonance between the hydraulic circuit, the synchronous machine and the turbine itself an acting as excitation source. This paper presents a systematic methodology for the assessment of the resonance risk for a given Francis turbine power plant. The test case investigated is a 1GW 4 Francis turbines power plant. The methodology is based on a transient simulation of the dynamic behavior of the whole power plant considering a 1D model of the hydraulic installation, comprising gallery, surge chamber, penstock, Francis turbine but also mechanical masses, synchronous machines, transformer, grid model, speed and voltage regulators. A stochastic excitation having energy uniformly distributed in the frequency range of interest is taken into account in the draft tube. As the vortex rope volume has a strong influence on the natural frequencies of the hydraulic system, the wave speed in the draft tube is considered as a parameter for the investigation. The transient simulation points out the key excitation frequencies and the draft tube wave speed producing resonance between the vortex rope excitation and the circuit and provide a good evaluation of the impact on power quality. The comparison with scale model tests results allows resonance risk assessment in the early stage of project pre-study. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8163930773735046, "perplexity": 1189.8444042226108}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917118477.15/warc/CC-MAIN-20170423031158-00309-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://quics.umd.edu/research/publications?s=year&%3Bf%5Bag%5D=K&o=desc&f%5Bauthor%5D=1228 | # Publications
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Filters: Author is Jerry M. Chow [Clear All Filters]
2015
, Demonstration of Robust Quantum Gate Tomography via Randomized Benchmarking, New Journal of Physics, vol. 17, no. 11, p. 113019, 2015. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8581818342208862, "perplexity": 11212.283268070836}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780056297.61/warc/CC-MAIN-20210918032926-20210918062926-00705.warc.gz"} |
http://www.iacr.org/conferences/crypto2009/acceptedpapers.html | # CRYPTO 2009 Accepted Papers
Reconstructing RSA Private Keys from Random Key Bits
We show that an RSA private key with small public exponent can be efficiently recovered given a 0.27 fraction of its bits at random. An important application of this work is to the "cold boot" attacks of Halderman et al. We make new observations about the structure of RSA keys that allow our algorithm to make use of the redundant information in the typical storage format of an RSA private key. Our algorithm itself is elementary and does not make use of the lattice techniques used in other RSA key reconstruction problems. We give an analysis of the running time behavior of our algorithm that matches the threshold phenomenon observed in our experiments.
Public-Key Cryptosystems Resilient to Key Leakage
Moni Naor and Gil Segev
Most of the work in the analysis of cryptographic schemes is concentrated in abstract adversarial models that do not capture {\em side-channel attacks}. Such attacks exploit various forms of unintended information leakage, which is inherent to almost all physical implementations. Inspired by recent side-channel attacks, especially the "cold boot attacks", Akavia, Goldwasser and Vaikuntanathan (TCC '09) formalized a realistic framework for modeling the security of encryption schemes against a wide class of side-channel attacks in which adversarially chosen functions of the secret key are leaked. In the setting of public-key encryption, Akavia et al. showed that Regev's lattice-based scheme (STOC '05) is resilient to any leakage of $L / \polylog(L)$ bits, where $L$ is the length of the secret key. In this paper we revisit the above-mentioned framework and establish the following results:
* We present a generic construction of a public-key encryption scheme that is resilient to key leakage from any {\em universal hash proof system}. The construction does not rely on additional computational assumptions, and the resulting scheme is as efficient as the underlying proof system. Existing constructions of such proof systems imply that our construction can be based on a variety of number-theoretic assumptions, including the decisional Diffie-Hellman assumption (and its progressively weaker $d$-Linear variants), the quadratic residuosity assumption, and Paillier's composite residuosity assumption.
* We construct a new hash proof system based on the decisional Diffie-Hellman assumption (and its $d$-Linear variants), and show that the resulting scheme is resilient to any leakage of $L(1 - o(1))$ bits. In addition, we prove that the recent scheme of Boneh et al. (CRYPTO '08), constructed to be a "circular-secure" encryption scheme, is resilient to any leakage of $L(1 - o(1))$ bits. These two proposed schemes complement each other in terms of efficiency.
* We extend the framework of key leakage to the setting of chosen-ciphertext attacks. On the theoretical side, we prove that the Naor-Yung paradigm is applicable in this setting as well, and obtain as a corollary encryption schemes that are CCA2-secure with any leakage of $L(1 - o(1))$ bits. On the practical side, we prove that variants of the Cramer-Shoup cryptosystem (along the lines of our generic construction) are CCA1-secure with any leakage of $L/4$ bits, and CCA2-secure with any leakage of $L/6$ bits.
Leakage-Resilient Public-Key Cryptography in the Bounded-Retrieval Model
Joel Alwen, Yevgeniy Dodis, and Daniel Wichs
We study the design of cryptographic primitives resilient to key-leakage attacks, where an attacker can repeatedly and adaptively learn information about the secret key, subject only to the constraint that the overall amount of such information is bounded by some parameter L. We construct a variety of leakage-resilient public-key systems including the first known identification schemes (ID), signature schemes and authenticated key agreement protocols (AKA). Our main result is an efficient three-round AKA in the Random-Oracle Model, which is resilient to key-leakage attacks that can occur prior-to and after a protocol execution. Our AKA protocol can be used as an interactive encryption scheme with qualitatively stronger privacy guarantees than non-interactive encryption schemes (constructed in prior and concurrent works), which are inherently insecure if the adversary can perform leakage attacks after seing a ciphertext.
Moreover, our schemes can be flexibly extended to the Bounded-Retrieval Model, allowing us to tolerate very large absolute amount of adversarial leakage L (potentially many gigabytes of information), only by increasing the size of the secret key and without any other loss of efficiency in communication or computation. Concretely, given any leakage parameter L, security parameter S, and any desired fraction E, our schemes have the following properties:
[1] Secret key size is L(1+E)+O(S).
[2] Public key size is O(S), and independent of L.
[3] Communication complexity is O(S/E),
and independent of L.
[4] Computation reads O(S/E^2) locations of the secret key, independent of L.
Lastly, we show that our schemes allow for repeated "invisible updates" of the secret key, allowing us to tolerate up to L bits of leakage in between any two updates, and an unlimited amount of leakage overall. These updates require that the parties can securely store a short "master update key" (e.g. on a separate secure device protected against leakage), which is only used for updates and not during protocol execution. The updates are invisible in the sense that a party can update its secret key at any point in time, without modifying the public key or notifying the other users.
Short Chosen-Prefix Collisions for MD5 and the Creation of a Rogue CA Certificate
Marc Stevens, Alexander Sotirov, Jacob Appelbaum, Arjen Lenstra, David Molnar, Dag Arne Osvik, and Benne de Weger
We present a refined chosen-prefix collision construction for MD5 that allowed creation of a rogue Certification Authority (CA) certificate, based on a collision with a regular end-user website certificate provided by a commercial CA. Compared to the previous construction from Eurocrypt 2007, this paper describes a more flexible family of differential paths and a new variable birthdaying search space. Combined with a time-memory trade-off, these improvements lead to just three pairs of near-collision blocks to generate the collision, enabling construction of RSA moduli that are sufficiently short to be accepted by current CAs. The entire construction is fast enough to allow for adequate prediction of certificate serial number and validity period: it can be made to require about $2^{49}$ MD5 compression function calls. Finally, we improve the complexity of identical-prefix collisions for MD5 to about $2^{16}$ MD5 compression function calls and use it to derive a practical single-block chosen-prefix collision construction of which an example is given.
Meet-in-the-Middle Preimage Attacks Against Reduced SHA-0 and SHA-1
Kazumaro Aoki and Yu Sasaki
Preimage resistance of several hash functions has already been broken by the meet-in-the-middle attacks and they utilize a property that their message schedules consist of only permutations of message words. It is unclear whether this type of attacks is applicable to a hash function whose message schedule does not consist of permutations of message words. This paper proposes new attacks against reduced SHA-0 and SHA-1 hash functions by analyzing a message schedule that does not consist of permutations but linear combinations of message words. The newly developed cryptanalytic techniques enable the meet-in-the-middle attack to be applied to reduced SHA-0 and SHA-1 hash functions. The attacks find preimages of SHA-0 and SHA-1 in $2^{156.6}$ and $2^{159.3}$ compression function computations up to 52 and 48 steps, respectively, compared to the brute-force attack, which requires $2^{160}$ compression function computations. The previous best attacks find preimages up to 49 and 44 steps, respectively.
Alice and Bob Go To Washington: A Cryptographic Theory of Politics and Policy
Edward W. Felten
Today more than ever, national leaders are making choices about technology: choices that influence how technology will develop, and choices whose consequences depend on technical questions. Yet many technologists find the accompanying policy debates and political processes mystifying or even borderline bogus, and therefore choose not to get involved. In fact, the policy process has its own internal logic which is sensible, or at least predictable, given the constraints involved in public decisionmaking. Some of the apparent bugs in the policy process, such as the tendency to decide without learning all of the relevant facts, are actually features. This talk will discuss how the policy process really works, using frequent analogies to cryptography. Understanding the policy process can help us to be better citizens, to engage in the policy process with more confidence and more effective results, and to do research that better serves the public interest.
Private Mutual Authentication and Conditional Oblivious Transfer
Stanislaw Jarecki and Xiaomin Liu
A bi-directional Private Authentication protocol, a.k.a. {\em Unlinkable Secret Handshake}, allows two parties to authenticate each other as certified by an appropriate certification authority, and hence affiliated with an appropriate group, in a {\em mutually private way} in the sense that the protocol reveals no information about inputs of either participant to a party which does not satisfy that participant's authentication policy. In particular, the protocol hides all information about that participant's certificate, including the group it belongs to, and authentication policy, including the group it is interested in, and protocol instances conducted by the same participant are unlinkable. We give the first practical realization of such private authentication, in a three round protocol (in ROM) with $O(1)$ exponentiations and bilinear maps, secure under Strong Diffie-Hellman and Decisional Linear assumptions.
Our protocol relies on a novel technical tool of independent interest, a family of efficient Private Conditional Oblivious Transfer (COT) protocols for a new class of languages. A COT protocol for language L allows sender $\Sd$ to encrypt message $m$ "under" statement $x$ so that receiver $\Rcv$ gets $m$ only if $\Rcv$ holds a witness for membership of $x$ in $L$, while $\Sd$ learns nothing from the protocol. A {\em private} COT for $L$ hides not only message $m$ but also statement $x$ from any $\Rcv$ that does not know a witness for it. We construct private COT's, secure under DDH, for languages defined by modular arithmetic constraints (e.g. equality, inequality, sums, products, etc) on discrete-log representations of group elements contained in statement $x$. (Recall that $(w_1,w_2,...,w_n)$ is a representation of $C$ in bases $(g_1,g_2,...,g_n)$ if $C=g_1^{w_1}g_2^{w_2}...g_n^{w_n}$.)
Randomizable Proofs and Delegatable Anonymous Credentials
Mira Belenkiy, Jan Camenisch, Melissa Chase, Markulf Kohlweiss, Anna Lysyanskaya, and Hovav Shacham
We construct an efficient delegatable anonymous credential system. Users can anonymously and unlinkably obtain credentials from any authority, delegate their credentials to other users, and prove possession of a credential L levels away from the given authority. The size of the proof (and time to compute it) is O(Lk), where k is the security parameter. The only other construction of delegatable anonymous credentials (Chase and Lysyanskaya, Crypto 2006) relies on general non-interactive proofs for NP-complete languages of size k (2L). We revise the entire approach to constructing anonymous credentials and identify randomizable zero-knowledge proof of knowledge systems as the key building block. We formally define the notion of randomizable non-interactive zero-knowledge proofs, and give the first construction by showing how to appropriately rerandomize Groth and Sahai (Eurocrypt 2008) proofs. We show that such proof systems, in combination with an appropriate authentication scheme and a few other protocols, allow us to construct delegatable anonymous credentials. Finally, we instantiate these building blocks under appropriate assumptions about groups with bilinear maps.
Computational Differential Privacy
Ilya Mironov, Omkant Pandey, Omer Reingold, and Salil Vadhan
The definition of differential privacy has recently emerged as a gold standard of privacy guarantees for algorithms on statistical databases. We offer several relaxations of the definition which require privacy guarantees to hold only against efficient---i.e.,~computationally-bounded---adversaries. We establish various relationships among these notions, and in doing so, we observe their close connection with the theory of pseudodense sets by Reingold et al. We extend the dense model theorem of Reingold et al. to demonstrate equivalence between two definitions (indistinguishability- and simulatability-based) of computational differential privacy.
Our computational analogues of differential privacy seem to allow for more accurate constructions (i.e., higher utility) than the standard information-theoretic analogues. In particular, in the context of private approximation of the distance between two vectors, we present a differentially-private protocol for computing the approximation, and contrast it with a substantially more accurate protocol that is only computationally differential private. Proving that this gap is inherent remains an interesting open problem.
Probabilistically Checkable Arguments
Yael Tauman Kalai and Ran Raz
We give a general reduction that converts any public-coin interactive proof into a one-round (two-message) argument. The reduction relies on a method proposed by Aiello {\em et al.}~\cite{ABOR00}, of using a Private-Information-Retrieval (PIR) scheme to collapse rounds in interactive protocols. For example, the reduction implies that for any security parameter $t$, the membership in any language in PSPACE can be proved by a one-round (two-message) argument of size $\poly(n,t)$, which is sound for malicious provers of size $2^t$. (Note that the honest prover in this construction runs in exponential time, since she has to prove membership in PSPACE, but we can choose $t$ such that $2^t$ is significantly larger than the running time of the honest prover).
A {\em probabilistically checkable argument} (PCA) is a relaxation of the notion of probabilistically checkable proof (PCP). It is defined analogously to PCP, except that the soundness property is required to hold only {\em computationally}. We consider the model where the argument is of one round (two-message), where the verifier's message depends only on his (private) randomness. We show that for membership in many NP languages, there are PCAs (with efficient honest provers) that are of size polynomial in the size of the {\em witness}. This compares to the best PCPs that are of size polynomial in the size of the {\em instance} (that may be significantly larger). The number of queries to these PCAs is poly-logarithmic. The soundness property, in all our results, relies on exponential hardness assumptions for PIR schemes.
On the Composition of Public-Coin Zero-Knowledge Protocols
Rafael Pas, Wei-Lung Dustin Tseng, Douglas Wikstr\"om
We show that only languages in BPP have public-coin, black-box zero-knowledge protocols that are secure under an unbounded (polynomial) number of parallel repetitions. This result holds both in the plain model (without any set-up) and in the Bare Public-Key Model (where the prover and the verifier have registered public keys). We complement this result by showing the existence of a public-coin black-box zero-knowledge proof that remains secure under any a-priori bounded number of concurrent executions.
On the Amortized Complexity of Zero-knowledge Protocols
Ronald Cramer and Ivan Damg{\aa}rd
We propose a general technique that allows improving the complexity of zero-knowledge protocols for a large class of problems where previously the best known solution was a simple cut-and-choose style protocol, i.e., where the size of a proof for problem instance $x$ and error probability $2^{-n}$ was $O(|x| n)$ bits. By using our technique to prove $n$ instances simultaneously, we can bring down the proof size per instance to $O(|x| + n)$ bits for the same error probability while using no computational assumptions. Examples where our technique applies include proofs for quadratic residuosity, proofs of subgroup membership and knowledge of discrete logarithms in groups of unknown order, and proofs of plaintext knowledge for various types of homomorphic encryptions schemes. The generality of our method stems from a somewhat surprising application of black-box secret sharing schemes.
Linear Algebra with Sub-linear Zero-Knowledge Arguments
Jens Groth
We suggest practical sub-linear size zero-knowledge arguments for statements involving linear algebra. Given commitments to matrices over a finite field, we give a sub-linear size zero-knowledge argument that one committed matrix is the product of two other committed matrices. We also offer a sub-linear size zero-knowledge argument for a committed matrix being equal to the Hadamard product of two other committed matrices. Armed with these tools we can give many other sub-linear size zero-knowledge arguments, for instance for a committed matrix being upper or lower triangular, a committed matrix being the inverse of another committed matrix, or a committed matrix being a permutation of another committed matrix.
A special case of what can be proved using our techniques is the satisfiability of an arithmetic circuit with $N$ gates. Our arithmetic circuit zero-knowledge argument has a communication complexity of $O(\sqrt{N})$ group elements. We give both a constant round variant and an $O(\log N)$ round variant of our zero-knowledge argument; the latter has a computation complexity of $O(N/\log N)$ exponentiations for the prover and $O(N)$ multiplications for the verifier making it efficient for the prover and very efficient for the verifier. In the case of a binary circuit consisting of NAND-gates we give a zero-knowledge argument of circuit satisfiability with a communication complexity of $O(\sqrt{N})$ group elements and a computation complexity of $O(N)$ multiplications for both the prover and the verifier.
New Birthday Attacks on Some MACs Based on Block Ciphers
Zheng Yuan, Wei Wang, Keting Jia, Guangwu Xu, and Xiaoyun Wang
This paper develops several new techniques of cryptanalyzing MACs based on block ciphers, and is divided into two parts.
The first part presents new distinguishers of the MAC construction \textsc{Alred} and its specific instance \textsc{Alpha}-MAC based on AES. For the \textsc{Alred} construction, we first describe a general distinguishing attack which leads to a forgery attack directly with the complexity of the birthday attack. A 2-round collision differential path of \textsc{Alpha}-MAC is adopted to construct a new distinguisher with about $2^{65.5}$ chosen messages and $2^{65.5}$ queries. One of the most important results is to use this new distinguisher to recover the internal state, which is an equivalent subkey of \textsc{Alpha}-MAC. Moreover, our distinguisher on \textsc{Alred} construction can be applied to the MACs based on CBC and CFB encryption modes.
The second part describes the first impossible differential attack on MACs-\textsc{Pelican}, MT-MAC-AES and PC-MAC-AES. Using the birthday attack, enough message pairs that produce the inner near-collision with some specific differences are detected, then the impossible differential attack on 4-round AES to the above mentioned MACs is performed. For \textsc{Pelican}, our attack recovers its internal state, which is an equivalent subkey. For MT-MAC-AES, the attack turns out to be a subkey recovery attack directly. The complexity of the two attacks is $2^{85.5}$ chosen messages and $2^{85.5}$ queries. For PC-MAC-AES, we recover its 256-bit key with $2^{85.5}$ chosen messages and $2^{128}$ queries.
Distinguisher and Related-Key Attack on the Full AES-256
Alex Biryukov, Dmitry Khovratovich, and Ivica Nikoli\'{c}
In this paper we construct a chosen-key distinguisher and a related-key attack on the full 256-bit key AES. We define a notion of {\em differential $q$-multicollision} and show that for AES-256 $q$-multicollisions can be constructed in time $q\cdot 2^{67}$ and with negligible memory, while we prove that the same task for an ideal cipher of the same block size would require at least $O(q\cdot 2^{\frac{q-1}{q+1}128})$ time. Using similar approach and with the same complexity we can also construct $q$-pseudo collisions for AES-256 in Davies-Meyer mode, a scheme which is provably secure in the ideal-cipher model. We have also computed partial $q$-multicollisions in time $q\cdot 2^{37}$ on a PC to verify our results. These results show that AES-256 can not model an ideal cipher in theoretical constructions. Finally we extend our results to find the first publicly known attack on the full 14-round AES-256: a related-key distinguisher which works for one out of every $2^{35}$ keys with $2^{120}$ data and time complexity and negligible memory. This distinguisher is translated into a key-recovery attack with total complexity of $2^{131}$ time and $2^{65}$ memory.
Cryptanalysis of C2
Julia Borghoff, Lars Knudsen, Gregor Leander, and Krystian Matusiewicz
We present several attacks on the block cipher C2, which is used for encrypting DVD Audio discs and Secure Digital cards. C2 has a 56 bit key and a secret $8$ to $8$ bit S-box. We show that if the attacker is allowed to choose the key, the S-box can be recovered in $2^{24}$ C2 encryptions. Attacking the $56$ bit key for a known S-box can be done in complexity $2^{48}$. Finally, a C2 implementation with a $8$ to $8$ bit secret S-box (equivalent to $2048$ secret bits) and a $56$ bit secret key can be attacked in $2^{53.5}$ C2 encryptions on average.
Message Authentication Codes from Unpredictable Block Ciphers
Yevgeniy Dodis and John Steinberger
We design an efficient mode of operation on block ciphers. Our mode has the following properties, when instantiated with a block cipher f to yield a variable-length, keyed hash function H:
(1) MAC Preservation. H is a secure message authentication code (MAC) with birthday security, as long as f is unpredictable.
(2) PRF Preservation. H$is a secure pseudorandom function (PRF) with birthday security, as long as f is pseudorandom. (3) Security against Side-Channels. As long as the block cipher f does not leak side-channel information about its internals to the attacker, properties (1) and (2) hold even if the remaining implementation of H is completely leaky. In particular, if the attacker can learn the transcript of all block cipher calls and other auxiliary information needed to implement our mode of operation. Our mode is the first to satisfy the MAC preservation property (1) with birthday security, solving the main open problem of Dodis et al. from Eurocrypt 2008. Combined with the PRF preservation (2), our mode provides a hedge against the case when the block cipher$f$is more secure as a MAC than as a PRF: if it is false, as we hope, we get a secure variable-length PRF; however, even if true, we still "salvage" a secure MAC, which might be enough for a given application. We also remark that no prior mode of operation offered birthday security against side channel attacks, even if the block cipher was assumed pseudorandom. Although very efficient, our mode is three times slower than many of the prior modes, such as CBC, which do not enjoy properties (1) and (3). Thus, our work motivates further research to understand the gap between unpredictability and pseudorandomness of the existing block ciphers, such as AES. How to Encipher Messages on a Small Domain: Deterministic Encryption and the Thorp Shuffle Ben Morris, Phillip Rogaway, and Till Stegers We analyze the security of the Thorp shuffle, or, equivalently, a maximally unbalanced Feistel network. Roughly said, the Thorp shuffle on~$N$cards mixes any$N^{1-1/r}$of them in$O(r\lg N)$steps. Correspondingly, making~$O(r)$passes of maximally unbalanced Feistel over an~$n$-bit string ensures CCA-security to$2^{n(1-1/r)}$queries. Our results, which employ Markov-chain techniques, enable the construction of a practical and provably-secure blockcipher-based scheme for deterministically enciphering credit card numbers and the like using a conventional blockcipher. How to Hash into Elliptic Curves Thomas Icart We describe a new explicit function that given an elliptic curve$E$defined over$\FF_{p^n}$, maps elements of$\FF_{p^n}$into$E$in \emph{deterministic} polynomial time and in a constant number of operations over$\FF_{p^n}$. The function requires to compute a cube root. As an application we show how to hash \emph{deterministically} into an elliptic curve. Batch Binary Edwards Daniel J. Bernstein This paper sets new software speed records for high-security Diffie--Hellman computations, specifically 251-bit elliptic-curve variable-base-point scalar multiplication. In one second of computation on a$200 Core 2 Quad Q6600 CPU, this paper's software performs 30000 251-bit scalar multiplications on the binary Edwards curve d(x+x^2+y+y^2)=(x+x^2)(y+y^2) over the field F_2[t]/(t^{251}+t^7+t^4+t^2+1) where d=t^{57}+t^{54}+t^{44}+1. The paper's field-arithmetic techniques can be applied in much more generality but have a particularly efficient interaction with the completeness of addition formulas for binary Edwards curves. See http://binary.cr.yp.to/edwards.html for more information.
Solving Hidden Number Problem with One Bit Oracle and Advice
In the {\em Hidden Number Problem (HNP)}, the goal is to find a hidden number $s$, when given $p$, $g$ and access to an oracle that on query $a$ returns the $k$ most significant bits of $s\cdot g^a \bmod p$.
We present an algorithm solving HNP, when given an advice depending only on $p$ and $g$; the running time and advice length are polynomial in $\log p$. This algorithm improves over prior HNP algorithms in achieving:
(1) optimal number of bits $k\ge 1$ (compared with $k\ge\Omega(\log\log p)$);
(2) robustness to random noise; and
(3) handling a wide family of predicates on top of the most significant bit.
As a central tool we present an algorithm that, given oracle access to a function $f$ over $\ZZ_N$, outputs all the significant Fourier coefficients of $f$ (\ie, those occupying, say, at least $1\%$ of the energy). This algorithm improves over prior works in being:
1. {\em Local.} Its running time is polynomial in $\log N$ and $L_1(\w f)$ (for $L_1(\w f)$ the sum of $f$'s Fourier coefficients, in absolute value).
2. {\em Universal.} For any $N,t$, the {\em same} oracle queries are asked for {\em all} functions $f$ over $\ZZ_N$ s.t. $L_1(\w f)\le t$.
3. {\em Robust.} The algorithm succeeds with high probability even if the oracle to $f$ is corrupted by random noise.
Computational Indistinguishability Amplification: Tight Product Theorems for System Composition
Ueli Maurer and Stefano Tessaro
Computational indistinguishability amplification is the problem of strengthening cryptographic primitives whose security is defined by bounding the distinguishing advantage of an efficient distinguisher. Examples include pseudorandom generators (PRGs), pseudorandom functions (PRFs), and pseudorandom permutations (PRPs).
The literature on computational indistinguishability amplification consists only of few isolated results. Yao's XOR-lemma implies, by a hybrid argument, that no efficient distinguisher has advantage better than (roughly) $n2^{m-1} \delta^m$ in distinguishing the XOR of $m$ independent $n$-bit PRG outputs $S_1,\ldots,S_m$ from uniform randomness if no efficient distinguisher has advantage more than $\delta$ in distinguishing $S_i$ from a uniform $n$-bit string. The factor $2^{m-1}$ allows for security amplification only if $\delta<\frac{1}{2}$: For the case of PRFs, a random-offset XOR-construction of Myers was the first result to achieve {\em strong} security amplification, i.e., also for $\frac{1}{2} \le \delta < 1$.
This paper proposes a systematic treatment of computational indistinguishability amplification. We generalize and improve the above product theorem for the XOR of PRGs along five axes. First, we prove the {\em tight} information-theoretic bound $2^{m-1}\delta^m$ (without factor $n$) also for the computational setting. Second, we prove results for {\em interactive} systems (e.g. PRFs or PRPs). Third, we consider the general class of {\em neutralizing combination constructions}, not just XOR. As an application this yields the first indistinguishability amplification results for the cascade of PRPs (i.e., block ciphers) converting a weak PRP into an arbitrarily strong PRP, both for single-sided and two-sided queries. Fourth, {\em strong} security amplification is achieved for a subclass of neutralizing constructions which includes as a special case the construction of Myers. As an application we obtain highly practical optimal security amplification for block ciphers, simply by adding random offsets at the input and output of the cascade. Fifth, we show strong security amplification also for {\em weakened assumptions} like security against random-input (as opposed to chosen-input) attacks.
A key technique is a generalization of Yao's XOR-lemma to (interactive) systems which is of independent interest.
Merkle Puzzles are Optimal - An O(n^2)-Query Attack on any Key Exchange from a Random Oracle
We prove that every key exchange protocol in the random oracle model in which the honest users make at most n queries to the oracle can be broken by an adversary making O(n^2) queries to the oracle. This improves on the previous Omega(n^6) query attack given by Impagliazzo and Rudich (STOC '89), and answers an open question posed by them. Our bound is optimal up to a constant factor since Merkle (CACM '78) gave a key exchange protocol that can easily be implemented in this model with n queries and cannot be broken by an adversary making o(n^2) queries.
Position Based Cryptography
Nishanth Chandran, Vipul Goyal, Ryan Moriarty, and Rafail Ostrovsky
We consider what constitutes {\em identities\/} in cryptography. Typical examples include your name and your social-security number, or your fingerprint/iris-scan, or your address, or your (non-revoked) public-key coming from some trusted public-key infrastructure. In many situations, however, {\bf where you are} defines your identity. For example, we know the role of a bank-teller behind a bullet-proof bank window not because she shows us her credentials but by merely knowing her location. In this paper, we initiate the study of cryptographic protocols where the identity (or other credentials and inputs) of a party are derived from its \emph{geographic location}.
We start by considering the central task in this setting, i.e., securely verifying the position of a device. Despite much work in this area, we show that in the Vanilla (or standard) model, the above task (i.e., of secure positioning) is impossible to achieve. In light of the above impossibility result, we then turn to the Bounded Storage Model and formalize and construct information theoretically secure protocols for two fundamental tasks:
* Secure Positioning; and
* Position Based Key Exchange.
We then show that these tasks are in fact {\em universal\/} in this setting -- we show how we can use them to realize Secure Multi-Party Computation.
Our main contribution in this paper is threefold: to place the problem of secure positioning on a sound theoretical footing; to prove a strong impossibility result that simultaneously shows the insecurity of previous attempts at the problem; and to present positive results by showing that the bounded-storage framework is, in fact, one of the "right"; frameworks (there may be others) to study the foundations of position-based cryptography.
Improving the Security of Quantum Protocols via Commit-and-Open
Ivan Damg{\aa}rd, Serge Fehr, Carolin Lunemann, Louis Salvail, and Christian Schaffner
We consider two-party quantum protocols starting with a transmission of some random BB84 qubits followed by classical messages. We show a general "compiler" improving the security of such protocols: if the original protocol is secure against an "almost honest" adversary, then the compiled protocol is secure against an arbitrary computationally bounded (quantum) adversary. The compilation preserves the number of qubits sent and the number of rounds up to a constant factor. The compiler also preserves security in the bounded-quantum-storage model (BQSM), so if the original protocol was BQSM-secure, the compiled protocol can only be broken by an adversary who has large quantum memory *and* large computing power. This is in contrast to known BQSM-secure protocols, where security breaks down completely if the adversary has larger quantum memory than expected. We show how our technique can be applied to quantum identification and oblivious transfer protocols.
Practical Cryptanalysis of ISO/IEC 9796-2 and EMV Signatures
Jean-S\'{e}bastien Coron, David Naccache, Mehdi Tibouchi, snd Ralf-Philipp Weinmann
In 1999, Coron, Naccache and Stern discovered an existential signature forgery for two popular RSA signature standards, ISO/IEC 9796-1 and 2. Following this attack ISO/IEC 9796-1 was withdrawn. ISO/IEC 9796-2 was amended by increasing the message digest to at least 160 bits. Attacking this amended version required at least $2^{61}$ operations.
In this paper, we exhibit algorithmic refinements allowing to attack the {\sl amended} (currently valid) version of ISO/IEC 9796-2 for all modulus sizes. A practical forgery was computed in only two days using 19 servers on the Amazon EC2 grid for a total cost of ~ US$800. The forgery was implemented for$e=2$but attacking odd exponents will not take longer. The forgery was computed for the RSA-2048 challenge modulus, whose factorization is still unknown. The new attack blends several theoretical tools. These do not change the asymptotic complexity of Coron et al.'s technique but significantly accelerate it for parameter values previously considered beyond reach. While less efficient (US$45,000), the acceleration also extends to EMV signatures. EMV is an ISO/IEC 9796-2-compliant format with extra redundancy. Luckily, this attack does not threaten any of the 730 million EMV payment cards in circulation for {\sl operational} reasons.
Costs are per modulus: after a first forgery for a given modulus, obtaining more forgeries is virtually immediate.
How Risky is the Random-Oracle Model?
Ga\"etan Leurent and Phong Q. Nguyen
RSA-FDH and many other schemes secure in the Random-Oracle Model (ROM) require a hash function with output size larger than standard sizes. We show that the random-oracle instantiations proposed in the literature for such cases are weaker than a random oracle, including the proposals by Bellare and Rogaway from 1993 and 1996, and the ones implicit in IEEE P1363 and PKCS standards: for instance, we obtain a $2^{67}$ preimage attack on BR93 for 1024-bit digests. Next, we study the security impact of hash function defects for ROM signatures. As an extreme case, we note that any hash collision would suffice to disclose the master key in the ID-based cryptosystem by Boneh et al. from FOCS '07, and the secret key in the Rabin-Williams signature for which Bernstein proved tight security at EUROCRYPT '08. Interestingly, for both of these schemes, a slight modification can prevent these attacks, while preserving the ROM security result. We give evidence that in the case of RSA and Rabin/Rabin-Williams, an appropriate PSS padding is more robust than all other paddings known.
Invited Talk: Abstraction in Cryptography
Ueli Maurer
Abstraction means to eliminate irrelevant details from consideration, thereby focusing only on the relevant aspects of a problem or context. Abstraction is of paramount importance in most scientific fields, especially in computer science and mathematics. The purpose of abstraction is to provide, at the same time, simpler definitions, higher generality of results, simpler proofs, improved elegance, and often better didactic suitability.
Abstraction can be a gradual process and need not be unique, but in many contexts, the highest achievable level of abstraction, once identified, appears natural and stable. For example, the abstract and natural concepts of a group or a field in algebra capture exactly what is required to prove many important results.
In the spirit of algebraic abstraction, we advocate the definition and use of higher levels of abstraction in cryptography, with the goal of identifying the highest possible level at which a definition or theorem should be stated and proved. Some questions one can ask are: What are abstractions of a system, a game, indistinguishability, a hybrid argument, a reduction, indifferentiability, or of (universal) composability? What are abstractions of efficient and negligible, and at which level of abstraction can computational and information-theoretic models be unified? And, of course: Can the abstract viewpoint lead to new concepts and results that are perhaps otherwise missed?
Asymptotically Good Ideal Linear Secret Sharing with Strong Multiplication over {\em Any} Fixed Finite Field
Ignacio Cascudo, Hao Chen, Ronald Cramer, and Chaoping Xing
This work deals with "MPC-friendly" linear secret sharing schemes (LSSS), a mathematical primitive upon which secure multi-party computation (MPC) can be based and which was introduced by Cramer, Damgaard and Maurer (EUROCRYPT 2000). Chen and Cramer proposed a special class of such schemes that is constructed from algebraic geometry and that enables efficient secure multi-party computation over fixed finite fields (CRYPTO 2006). We extend this in four ways. First, we propose an abstract coding-theoretic framework in which this class of schemes and its (asymptotic) properties can be cast and analyzed. Second, we show that for {\em every finite field} $\FF_q$, there exists an infinite family of LSSS over $\FF_q$ that is asymptotically good in the following sense: the schemes are "{\em ideal}," i.e., each share consists of a single $\FF_q$-element, and the schemes have {\em $t$-strong multiplication} on $n$ players, where the corruption tolerance $\frac{3t}{n-1}$ tends to a constant $\nu(q)$ with $0<\nu(q)<1$ when $n$ tends to infinity. Moreover, when $|\FF_q|$ tends to infinity, $\nu(q)$ tends to $1$, which is optimal. This leads to explicit lower bounds on $\widehat{\tau}(q)$, our measure of {\em asymptotic optimal corruption tolerance}.
We achieve this by combining the results of Chen and Cramer with a dedicated field-descent method. In particular, in the $\FF_2$-case there exists a family of binary $t$-strongly multiplicative ideal LSSS with $\frac{3t}{n-1}\approx 2.86\%$ when $n$ tends to infinity, a one-bit secret and just a one-bit share for every player. Previously, such results were shown for $\FF_q$ with $q\geq 49$ a square. Third, we present an infinite family of ideal schemes with $t$-strong multiplication that does not rely on algebraic geometry and that works over every finite field $\FF_q$. Its corruption tolerance vanishes, yet still $\frac{3t}{n-1}= \Omega(1/(\log\log n)\log n)$. Fourth and finally, we give an improved non-asymptotic upper bound on corruption tolerance.
The Round Complexity of Verifiable Secret Sharing Revisted
Arpita Patra, Ashish Choudhary, Tal Rabin, and Pandu Rangan
The round complexity of interactive protocols is one of their most important complexity measures. The investigation of the round complexity of protocols is usually conducted under the assumption that the protocols are error-free. In this paper we examine the question of whether introducing a probability of error into the executions can improve on known results and lower bounds. We study this question for the specific task of Verifiable Secret Sharing.
Verifiable Secret Sharing (VSS) is a fundamental primitive used as a building block in many distributed cryptographic tasks, such as Multiparty Computation and Byzantine Agreement. VSS is a two phase (Share, Reconstruct) protocol carried out among $n$ parties in the presence of a computationally unbounded adversary who can corrupt up to $t$ parties. We assume that every two parties in the network are connected by a pairwise secure channel and a public broadcast channel is available to all.
In this work we prove that existing lower bounds for the round complexity of VSS can be circumvented by introducing a negligible probability of error in the reconstruction phase. Previous results show that matching lower and upper bounds of {\em three} rounds for VSS exist, with $n = 3t+1$, where the lower bound holds for protocols where reconstruction always succeeds, i.e. with probability 1. In contrast we show that with a negligible probability of error in the reconstruction phase:
1. There exists an efficient 2-round VSS protocol for $n = 3t + 1$. This protocol has a 2-round reconstruction phase. If we assume that the adversary is non-rushing then we can achieve a 1-round reconstruction phase.
2. There exists an efficient 1-round VSS for $t = 1$ and $n > 3$.
3. We prove that our results are optimal both in resilience and number of rounds by proving: a. There does not exist a 2-round WSS (and hence VSS) for $n \leq 3t$. b. There is no 1-round VSS protocol for $t \geq 2$ and $n \geq 4$.
Somewhat Non-Committing Encryption and Efficient Adaptively Secure Oblivious Transfer
Juan Garay, Daniel Wichs, and Hong-Sheng Zhou
We solve the latter problem by means of a new primitive that we call {\em somewhat non-committing encryption} resulting in significant efficiency improvements over the standard method for realizing secure channels using (fully) non-committing encryption. Somewhat non-committing encryption has two parameters: an equivocality parameter $\ell$ (measuring the number of ways that a ciphertext can be "opened") and the message sizes $k$. Our implementation is very efficient for small values $\ell$, \emph{even} when $k$ is large. This translates into a very efficient compilation of semi-adaptively secure protocols for tasks with small input/output domains (such as bit-OT) into fully adaptively secure protocols.
Indeed, we showcase our methodology by applying it to the recent Oblivious Transfer protocol by Peikert \etal [Crypto 2008], which is only secure against static corruptions, to obtain the first efficient, adaptively secure and composable OT protocol. In particular, to transfer an $n$-bit message, we use a constant number of rounds and $O(n)$ public key operations.
Collusion-Free Multiparty Computation in the Mediated Model
Joel Alwen, Jonathan Katz, Yehuda Lindell, Giuseppe Persiano, abhi shelat, and Ivan Visconti
Collusion-free protocols prevent subliminal communication (i.e., covert channels) between parties running the protocol. In the standard communication model, if one-way functions exist, then protocols satisfying any reasonable degree of privacy cannot be collusion-free. To circumvent this impossibility, Alwen, shelat and Visconti (CRYPTO 2008) recently suggested the _mediated model_ where all communication passes through a mediator. The goal is to design protocols where collusion-freeness is guaranteed as long as the mediator is honest, while standard security guarantees hold if the mediator is dishonest. In this model, they gave constructions of collusion-free protocols for commitments and zero-knowledge proofs in the two-party setting.
We strengthen the definition of Alwen et al., and resolve the main open questions in this area by showing a collusion-free protocol (in the mediated model) for computing any multi-party functionality.
Privacy-Enhancing Auctions Using Rational Cryptography
Peter Bro Miltersen, Jesper Buus Nielsen, and Nikos Triandopoulos
We consider enhancing with privacy concerns a large class of auctions, which include sealed-bid single-item auctions but also general multi-item multi-winner auctions, our assumption being that bidders primarily care about monetary payoff and secondarily worry about exposing information about their type to other players and learning information about other players' types, that is, bidders are \emph{greedy then paranoid}. To treat privacy explicitly within the game theoretic context, we put forward a novel \emph{hybrid utility} model that considers both monetary and privacy components in players' payoffs.
We show how to use rational cryptography to approximately implement any given \emph{ex interim} individually strictly rational equilibrium of such an auction without a trusted mediator through a cryptographic protocol that uses only point-to-point authenticated channels between the players. By "ex interim individually strictly rational" we mean that, given its type and before making its move, each player has a strictly positive expected utility. By "approximately implement" we mean that, under cryptographic assumptions, running the protocol is a computational Nash equilibrium with a payoff profile negligibly close to the original equilibrium.
Utility Dependence in Correct and Fair Rational Secret Sharing
The problem of carrying out cryptographic computations when the participating parties are \emph{rational} in a game-theoretic sense has recently gained much attention. One problem that has been studied considerably is that of rational secret sharing. In this setting, the aim is to construct a mechanism (protocol) so that parties behaving rationally have incentive to cooperate and provide their shares in the reconstruction phase, even if each party prefers to be the only one to learn the secret.
Although this question was only recently asked by Halpern and Teague (STOC 2004), a number of works with beautiful ideas have been presented to solve this problem. However, they all have the property that the protocols constructed need to know the actual utility values of the parties (or at least a bound on them). This assumption is very problematic because the utilities of parties are not public knowledge. We ask whether this \emph{dependence on the actual utility values} is really necessary and prove that in the basic setting, rational secret sharing cannot be achieved without it. On the positive side, we show that by somewhat relaxing the standard assumptions on the utility functions, it is possible to achieve utility independence. In addition to the above, observe that the known protocols for rational secret sharing that do not assume simultaneous channels all suffer from the problem that one of the parties can cause the others to output an incorrect value. (This problem arises when a party gains higher utility by having another output an incorrect value than by learning the secret itself; we argue that such a scenario is not at all unlikely.) We show that this problem is inherent in the non-simultaneous channels model, unless the actual values of the parties' utilities for this attack is known, in which case it is possible to prevent this from happening.
On Bounded Distance Decoding, Unique Shortest Vectors, and the Minimum Distance Problem
We prove the equivalence, up to a small polynomial approximation factor $\sqrt{n/\log n}$, of the lattice problems $\uSVP$ (unique Shortest Vector Problem), $\BDD$ (Bounded Distance Decoding) and $\GapSVP$ (the decision version of the Shortest Vector Problem). This resolves a long-standing open problem about the relationship between uSVP and the more standard $\GapSVP$, as well the $\BDD$ problem commonly used in coding theory. The main cryptographic application of our work is the proof that the Ajtai-Dwork (\cite{Ajtai+Dwork-PublCrypwithEqui:97}) and the Regev (\cite{DBLP:journals/jacm/Regev04}) cryptosystems, which were previously only known to be based on the hardness of $\uSVP$, can be equivalently based on the hardness of worst-case GapSVP$_{O(n^{2.5})}$ and GapSVP$_{O(n^{2})}$, respectively. Also, in the case of $\uSVP$ and $\BDD$, our connection is very tight, establishing the equivalence (within a small constant approximation factor) between the two most central problems used in lattice based public key cryptography and coding theory.
Fast Cryptographic Primitives and Circular-Secure Encryption Based on Hard Learning Problems
Benny Applebaum, David Cash, Chris Peikert, and Amit Sahai
The well-studied task of \emph{learning a linear function with errors} is a seemingly hard problem and the basis for several cryptographic schemes. Here we demonstrate additional applications that enjoy strong security properties and a high level of efficiency. Namely, we construct:
* Public-key and symmetric-key cryptosystems that provide security for \emph{key-dependent messages} and enjoy \emph{circular security}. Our schemes are highly efficient: in both cases the ciphertext is only a constant factor larger than the plaintext, and the cost of encryption and decryption is only $n\cdot \polylog(n)$ bit operations per message symbol in the public-key case, and $\polylog(n)$ bit operations in the symmetric-case.
* Two efficient pseudorandom objects: a "weak randomized pseudorandom function" --- a relaxation of standard PRF --- that can be computed obliviously via a simple protocol, and a length-doubling pseudorandom generator that can be computed by a circuit of $n \cdot \polylog(n)$ size. The complexity of our pseudorandom generator almost matches the complexity of the fastest known construction (Applebaum \etal, RANDOM 2006), which runs in linear time at the expense of relying on a nonstandard intractability assumption.
Our constructions and security proofs are simple and natural, and involve new techniques that may be of independent interest. In addition, by combining our constructions with prior ones, we get fast implementations of several other primitives and protocols.
Dual System Encryption: Realizing Fully Secure IBE and HIBE under Simple Assumptions
Brent Waters
We present a new methodology for proving security of encryption systems using what we call Dual System Encryption. Our techniques result in fully secure Identity-Based Encryption (IBE) and Hierarchical Identity-Based Encryption (HIBE) systems under the simple and established decisional Bilinear Diffie-Hellman and decisional Linear assumptions. Our IBE system has ciphertexts, private keys, and public parameters each consisting of a constant number of group elements. These results are the first HIBE system and the first IBE system with short parameters under simple assumptions.
In a Dual System Encryption system both ciphertexts and private keys can take on one of two indistinguishable forms. A private key or ciphertext will be normal if they are generated respectively from the system's key generation or encryption algorithm. These keys and ciphertexts will behave as one expects in an IBE system. In addition, we define semi-functional keys and ciphertexts. A semi-functional private key will be able to decrypt all normally generated ciphertexts; however, decryption will fail if one attempts to decrypt a semi-functional ciphertext with a semi-functional private key. Analogously, semi-functional ciphertexts will be decryptable only by normal private keys.
Dual System Encryption opens up a new way to prove security of IBE and related encryption systems. We define a sequence of games where we change first the challenge ciphertext and then the private keys one by one to be semi-functional. We finally end up in a game where the challenge ciphertext and all private keys are semi-functional at which point proving security is straightforward.
The Group of Signed Quadratic Residues and Applications
Dennis Hofheinz and Eike Kiltz
We consider the cryptographic group of \emph{Signed Quadratic Residues}. This group is particularly useful for cryptography since it is a "gap-group," in which the computational problem (i.e., computing square roots) is as hard as factoring, while the corresponding decisional problem (i.e., recognizing \emph{signed} quadratic residues) is easy. We are able to show that under the factoring assumption, the Strong Diffie-Hellman assumption over the signed quadratic residues holds. That is, in this group the Diffie-Hellman problem is hard, even in the presence of a Decisional Diffie-Hellman oracle.
We demonstrate the usefulness of our results by applying them to the Hybrid ElGamal encryption scheme (aka Diffie-Hellman integrated encryption scheme --- DHIES). Concretely, we consider the security of the scheme when instantiated over the group of signed quadratic residues. It is known that, in the random oracle model, the scheme is chosen-ciphertext (CCA) secure under the Strong Diffie-Hellman assumption and hence, by our results, under the standard factoring assumption. We show that furthermore, in the standard model, Hybrid ElGamal is CCA secure under the higher residuosity assumption, given that the used hash function is four-wise independent. The latter result is obtained using the recent "randomness extraction framework" for hash proof systems.
Short and Stateless Signatures from the RSA Assumption
Susan Hohenberger and Brent Waters
We present the first signature scheme which is "short", stateless and secure under the RSA assumption in the standard model. Prior short, standard model signatures in the RSA setting required either a strong complexity assumption such as Strong RSA or (recently) that the signer maintain state. A signature in our scheme is comprised of one element in Z_N* and one integer. The public key is also short, requiring only the modulus N, one element of Z_N*, one integer and one PRF seed.
To design our signature, we employ the known generic construction of fully-secure signatures from weakly-secure signatures and a chameleon hash. We then introduce a new proof technique for reasoning about weakly-secure signatures. This technique enables the simulator to predict a prefix of the message on which the adversary will forge and knowledge of this prefix is used to embed the challenge. This technique has wider applications beyond RSA.
We also use it to provide an entirely new analysis of the security of the Waters signatures: the only short, stateless signatures known to be secure under the Computational Diffie-Hellman assumption in the standard model.
Smooth Projective Hashing for Conditionally Extractable Commitments
Michel Abdalla, C\'{e}line Chevalier, and David Pointcheval
The notion of smooth projective hash functions was proposed by Cramer and Shoup and can be seen as special type of zero-knowledge proof system for a language. Though originally used as a means to build efficient chosen-ciphertext secure public-key encryption schemes, some variations of the Cramer-Shoup smooth projective hash functions also found applications in several other contexts, such as password-based authenticated key exchange and oblivious transfer. In this paper, we first address the problem of building smooth projective hash functions for more complex languages. More precisely, we show how to build such functions for languages that can be described in terms of disjunctions and conjunctions of simpler languages for which smooth projective hash functions are known to exist. Next, we illustrate how the use of smooth projective hash functions with more complex languages can be efficiently associated to extractable commitment schemes and avoid the need for zero-knowledge proofs. Finally, we explain how to apply these results to provide more efficient solutions to two well-known cryptographic problems: a public-key certification which guarantees the knowledge of the private key by the user without random oracles or zero-knowledge proofs and adaptive security for password-based authenticated key exchange protocols in the universal composability framework with erasures. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7194840312004089, "perplexity": 1469.727338504803}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438043060830.93/warc/CC-MAIN-20150728002420-00339-ip-10-236-191-2.ec2.internal.warc.gz"} |
http://mathhelpforum.com/algebra/161591-expanding-quadratic-expressions-answers-needed.html#post577739 | 1) Expand and Simplify
(4x-3)(x+5)
2) Prove that
(n+5)^2 - (n+3)^2 = 4(n+4)
3)
a) Expand and simplify (2n+1)^2
b) Prove that the square of any odd number is always 1 more than a multiple of 8.
4) Expand and simplify (x-3)(2x+1)
5)
a) Expand and simplify (x+y)(x-y)
b) Using your answer to part (a). or otherwise, find the exact value of
780^2 - 220^2
2. What have you tried yourself? What do you have problems with?
3. Could you perhaps give a brief step by step guide as to what to do?
I missed alot of work on this and i'm struggling. Thanks.
4. 1) Multiply 1st term in first bracket by 1st term in second bracket
Add to this, the product of the 1st term in the 1st bracket and the 2nd term in the 2nd bracket
Add to this, the product of the 2nd term in the 1st bracket and the 1st term in the 2nd bracket
Add to this, the product of the 2nd term in the 1st bracket and the 2nd term in the 2nd bracket
2) Can you expand the two brackets on the left?
We'll do the others after those.
5. 1)
4x * x = 4x^2
4x * 5 = 20x
-3 * x = -3x
-3 * 5 = -15
= 4x^2 + 20x -3x -15
Correct so far?
6. Yes, you simplify now, taking the part containing: 20x - 3x
7. 8x + 17x - 15?
8. Great! Next number now.
9. How do you expand the two brackets on the left? >_<
10. Just like you did for the first one.
(n+5)^2 - (n+3)^2 = (n+5)(n+5) - (n+3)(n+3)
You'll notice that if you have something of the type:
$(a+b)^2$
It expands in the fom:
$a^2 + 2ab + b^2$
But for the time being, expand it like you did for 1)
11. Whilst doing this, do I ignore the powers?
12. You already took the powers into consideration.
Doesn't
$5^2 = 5\times5 = 25$
$x^2 = x \times x$
Similarly,
$(n+5)^2 = (n+5)(n+5)$
13. (n+5)^2 - (n+3)^2
n x n = n^2
n x 3 = 3n
5 x n = 5n
5 x 3 = 15
n^2 + 3n + 5n + 15
= N^2 + 8n + 15
Did i do it right? :S
14. No, you didn't get my point.
First expand (n+5)^2.
Then expand (n+3)^2.
Lastly, subtract the two expansions.
15. Originally Posted by Roxas
(n+5)^2 - (n+3)^2
n x n = n^2
n x 3 = 3n
5 x n = 5n
5 x 3 = 15
n^2 + 3n + 5n + 15
= N^2 + 8n + 15
Did i do it right? :S
No. If you want to do it by expanding each term, then you need to recall that (a + b)^2 = a^2 + 2ab + b^2. After correctly expanding, you then need to correctly take the difference. It should be clear, for example, that the final answer will NOT include n^2 ....
I suggest you get a copy of the class notes that you missed and review them carefully. Your textbook will also have exmaples that you should carefully review.
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https://bugreports.qt.io/browse/QTCREATORBUG-23440?gerritReviewStatus=All | Build progress goes to 100% much before build is done
XMLWordPrintable
Details
• Type: Bug
• Status: Closed
• Priority: Not Evaluated
• Resolution: Out of scope
• Affects Version/s: Qt Creator 4.11.0
• Fix Version/s: None
• Component/s:
• Labels:
• Platform/s:
Linux/X11
Description
I upgraded from v4.9.0 to v4.11.0 and now the build progress bar is broken. I build with CMake+Ninja. The problem is that the build progress bar reaches 100% or very near while the build is not even half-way done.
I am not sure what information I can provide that can help you troubleshoot this, but I am happy to provide whatever you ask for. Also, I run a Qt Creator that I build from git, so I can test patches. I can also take a look at the problem myself, but in that case, I would appreciate someone pointing me at good "suspects"
People
• Assignee:
Tobias Hunger
Reporter:
Thomas Sondergaard | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9505889415740967, "perplexity": 3838.2668728783756}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370506959.34/warc/CC-MAIN-20200402111815-20200402141815-00389.warc.gz"} |
http://mathhelpforum.com/algebra/84995-finding-two-unknows-one-equation.html | # Math Help - Finding two unknows from one equation
1. ## Finding two unknows from one equation
Dear members
I have been set a task to find n and m (two constants) in the following equation: N=(z^m).(r^n). I have been provided with data for N, z and r. I am assuming that I can plot this data to find m and n, but I am unsure on how to rearrange the equation to achieve this. I would be appreciative of your help.
Thanks
2. $N = z^{m} \cdot r^{n}$
$ln(N) = ln(z^{m} \cdot r^{n}) = m\cdot ln(z) + n\cdot ln(r)$
If we let $ln(z) = x \mbox{ and } ln(r) = y \mbox{ and } ln(N)=c$, then
$\left[ \begin{matrix} m\cdot x_{1} & n\cdot y_{1} \\ m\cdot x_{2} & n\cdot y_{2} \end{matrix}\right] = \left[ \begin{matrix} x_{1} & y_{1} \\ x_{2} & y_{2} \end{matrix}\right] \, \left[ \begin{matrix} m \\ n \end{matrix} \right]$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 4, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8770449757575989, "perplexity": 448.6036768927798}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1430457725048.66/warc/CC-MAIN-20150501052205-00095-ip-10-235-10-82.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/perturbative-expansion-of-beta-function-renormalization.898004/ | # A Perturbative expansion of Beta function - Renormalization
1. Dec 21, 2016
### nigelscott
I am trying to understand the basics of Renormalization. I have read that β encodes the running coupling and can be expanded as a power series as:
β(g) = ∂g/(∂ln(μ)) = β0g3 + β1g5 + ...
However, I don't understand how this is derived.. I assume that the terms correspond to 1 loop, 2 loops etc. Can somebody help me out.
2. Dec 27, 2016
### Greg Bernhardt
Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.
Draft saved Draft deleted
Similar Discussions: Perturbative expansion of Beta function - Renormalization | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8110175132751465, "perplexity": 1608.4216772377715}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320215.92/warc/CC-MAIN-20170624031945-20170624051945-00164.warc.gz"} |
http://zbmath.org/?q=an:0616.10025 | # zbMATH — the first resource for mathematics
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Geometry Search for the term Geometry in any field. Queries are case-independent. Funct* Wildcard queries are specified by * (e.g. functions, functorial, etc.). Otherwise the search is exact. "Topological group" Phrases (multi-words) should be set in "straight quotation marks". au: Bourbaki & ti: Algebra Search for author and title. The and-operator & is default and can be omitted. Chebyshev | Tschebyscheff The or-operator | allows to search for Chebyshev or Tschebyscheff. "Quasi* map*" py: 1989 The resulting documents have publication year 1989. so: Eur* J* Mat* Soc* cc: 14 Search for publications in a particular source with a Mathematics Subject Classification code (cc) in 14. "Partial diff* eq*" ! elliptic The not-operator ! eliminates all results containing the word elliptic. dt: b & au: Hilbert The document type is set to books; alternatively: j for journal articles, a for book articles. py: 2000-2015 cc: (94A | 11T) Number ranges are accepted. Terms can be grouped within (parentheses). la: chinese Find documents in a given language. ISO 639-1 language codes can also be used.
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On the $l$-adic representations associated to Hilbert modular forms. (Sur les représentations $l$-adiques associées aux formes modulaires de Hilbert.) (French) Zbl 0616.10025
Let $\pi ={\otimes }_{v}{\pi }_{v}$ be a cuspidal automorphic representation of ${\text{GL}}_{2}\left({F}_{𝔸}\right)$ where ${F}_{𝔸}$ is the ring of adeles of a totally real algebraic number field $F$ of degree $d$ over $ℚ$, of the same type as representations corresponding to Hilbert modular forms of weight $\left({k}_{1},···,{k}_{d}\right)$, i.e. whose local components ${\pi }_{v}$ for each of the $d$ Archimedean places $v$ of $F$ are essentially square integrable representations of ${\text{GL}}_{2}\left(ℝ\right)$ occurring in the induced representation $\text{Ind}\left(\mu ,\nu \right)$ (under unitary induction) with characters $\mu$, $\nu$ of ${ℝ}^{*}$ given by $\mu \left(t\right):={|t|}^{\left(k-w-1\right)/2}{\left(\text{sgn}\phantom{\rule{0.166667em}{0ex}}t\right)}^{k}$, $\nu \left(t\right):={|t|}^{\left(-k-w+1\right)/2}$ for integral $k\ge 2$ and $w\equiv k\phantom{\rule{4.44443pt}{0ex}}\left(mod\phantom{\rule{0.277778em}{0ex}}2\right)$, all depending on $v$. For $d$ even, ${\pi }_{v}$ is taken to be a special or cuspidal representation of ${\text{GL}}_{2}\left({F}_{v}\right)$, for at least one non-Archimedean place $v$ of $F$. Let $\overline{F}$ be an algebraic closure of $F$.
The main theorem proved is the following: there exists an algebraic number field $E$ depending on the given $\pi$ and a strictly compatible system $\left\{{\sigma }^{\lambda }\right\}$ of continuous 2-dimensional ${E}_{\lambda }$-adic representations of $\text{Gal}\left(\overline{F}/F\right)$ such that for every non-Archimedean place $v$ of $F$ and $\lambda$ of $E$ with residue characteristic different from that of $v$, the restriction ${\sigma }_{v}^{\lambda }$ of ${\sigma }^{\lambda }$ to the local Weil group $W{F}_{v}$ is equivalent to ${\sigma }^{\lambda }\left({\pi }_{v}\right)·$
What is new here is that the author determines ${\sigma }_{v}^{\lambda }$ for every non-Archimedean place $v$ of $F$. Moreover, according to Ribet, ${\sigma }^{\lambda }$ turns out to be irreducible and as such, is characterized entirely.
First, for a weaker version of the main theorem, the author gives a (“geometric”) proof and then he uses ”base change for $\text{GL}\left(2\right)$” to deduce the main theorem. As a corollary of the main theorem for $d=1$ and weight $k=2$, the author shows an affirmative answer to a conjecture on Weil curves over $ℚ$.
Reviewer: S. Raghavan
##### MSC:
11F70 Representation-theoretic methods in automorphic theory 11F67 Special values of automorphic $L$-series, etc 11G25 Varieties over finite and local fields 11F41 Hilbert modular forms and surfaces | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 54, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8635106086730957, "perplexity": 1171.8482941028685}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1393999653202/warc/CC-MAIN-20140305060733-00003-ip-10-183-142-35.ec2.internal.warc.gz"} |
http://clay6.com/qa/21269/ultraviolet-light-of-wavelength-2271-a-from-a-100-w-mercury-source-irradiat | # Ultraviolet light of wavelength $2271\: A^{\circ}$ from a $100\: W$ mercury source irradiates a photocell made of molybdenum metal. If the stopping potential is $-1.3\: V$,will the photocell respond to a high intensity $(10^{-5}W/m^2)$ red light of wavelength $632.8\: A^{\circ}$ produced by a He-Ne laser?
$\begin {array} {1 1} (a)\;yes & \quad (b)\;no \\ (c)\;maybe & \quad (d)\;can’t\: be\: determined \end {array}$
Ans : (a)
$\lambda = 2271 \times 10^{-10} m\: \: \: \: \: \: \: V_{\circ}= 1.3 V$
So, $\phi_{\circ}=hv - eV_{\circ}$
$= \large\frac{hc}{\lambda} - eV_{\circ}$
$= \large\frac{6.6 \times 10^{-34} \times 3 \times 10^8}{(2271 \times10^{-10} ) – 1.6 \times 10^{-19} \times 1.3}$
$= 8.72 \times 106{-19} – 2.08 \times 10^{-19}$
$= 6.64 \times 10^{-19} J$
$= \large\frac{6.64 \times 10^{-19}}{ 1.6 \times 10^{-19} } = 4.15\: eV$
So,$v_{\circ}$ = threshold frequency of metal = $\large\frac{\phi_{\circ}}{h}$
$= \large\frac{6.64 \times 10^{-19}}{6.6 \times 10^{-34} } = 1.006 \times 10^{15}Hz$
$\lambda_r=$ wavelength of red light $= 632.8\: A^{\circ} = 6328 \times 10^{-11}m$
So, $v_r= \large\frac{c}{\lambda_r} = \large\frac{3 \times 10^8}{ 6328 \times 10^{-11} } = 4.74 \times 10^{15}Hz$
Since,$v_{\circ} < v_r$ , so photocell would respond.
edited Mar 13, 2014 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5621674656867981, "perplexity": 4440.546589407889}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794863923.6/warc/CC-MAIN-20180521023747-20180521043747-00341.warc.gz"} |
https://zbmath.org/?q=ut%3Aparameter-robust+LBB+stability+ai%3Ahong.qingguo | ×
## Conservative discretizations and parameter-robust preconditioners for Biot and multiple-network flux-based poroelasticity models.(English)Zbl 1463.65372
Summary: The parameters in the governing system of partial differential equations of multiple-network poroelasticity models typically vary over several orders of magnitude, making its stable discretization and efficient solution a challenging task. In this paper, we prove the uniform Ladyzhenskaya-Babuška-Brezzi (LBB) condition and design uniformly stable discretizations and parameter-robust preconditioners for flux-based formulations of multiporosity/multipermeability systems. Novel parameter-matrix-dependent norms that provide the key for establishing uniform LBB stability of the continuous problem are introduced. As a result, the stability estimates presented here are uniform not only with respect to the Lamé parameter $$\lambda$$ but also to all the other model parameters, such as the permeability coefficients $$K_i$$; storage coefficients $$c_{p_i}$$; network transfer coefficients $$\beta_{ij}$$, $$i,j=1,\dots,n$$; the scale of the networks $$n$$; and the time step size $$\tau$$. Moreover, strongly mass-conservative discretizations that meet the required conditions for parameter-robust LBB stability are suggested and corresponding optimal error estimates proved. The transfer of the canonical (norm-equivalent) operator preconditioners from the continuous to the discrete level lays the foundation for optimal and fully robust iterative solution methods. The theoretical results are confirmed in numerical experiments that are motivated by practical applications.
### MSC:
65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs 65N12 Stability and convergence of numerical methods for boundary value problems involving PDEs 65F08 Preconditioners for iterative methods 65F10 Iterative numerical methods for linear systems 76S05 Flows in porous media; filtration; seepage 74F10 Fluid-solid interactions (including aero- and hydro-elasticity, porosity, etc.)
FEniCS
Full Text: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7555381655693054, "perplexity": 1227.2229627770057}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571950.76/warc/CC-MAIN-20220813111851-20220813141851-00792.warc.gz"} |
https://www.flapw.de/MaX-5.0/documentation/kPointSetSetup/ | k-point set setup
Creation of k-point sets
While you can use the documentation provided here to generate you own $\vec{k}$-point. It is usually recommended and much simpler to use input generator for this task.
In the FLEUR inp.xml file you typically find a series of XML-tags like this the cell section:
<bzIntegration valenceElectrons="20.00000000" mode="hist" fermiSmearingEnergy=".00100000">
<Kpointlistselection Listname="Default" />
<Kpointlists>
<Kpointlist Name="Default" Count="2" Type="Path">
<kPoint weight="0.050000">0.025000 0.000000 0.000000</kPoint>
<kPoint weight="0.050000">0.450000 0.000000 0.000000</kPoint>
</Kpointlist>
</kPointLists>
</bzIntegration>
Alternatively, the KpointLists might be put into a separate kpts.xml file and in the inp.xml you find the corresponding include.
<bzIntegration valenceElectrons="20.00000000" mode="hist" fermiSmearingEnergy=".00100000">
<Kpointlistselection Listname="Default" />
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="kpts.xml">
</bzIntegration>
Brillouin zone integration
The highest level tag to be found is the bzIntegration tag:
Attribute Desciption
valenceElectrons The total number of valence electrons in your system
mode Method to determine the Fermi level. Supported are:
hist - Use the histogram mode. This is the default.
gauss - Use Gaussian smearing.
tria - Use the tetrahedron method.
fermiSmearingEnergy The Fermi smearing can be parametrized by this energy in Hartree.
fermiSmearingTemp As an alternative to fermiSmearingEnergy a Fermi smearing temperature can be set in Kelvin.
Selecting a k-point set
Then, the Kpointlistselection tag with a single attribute Listname is used to select the k-point set from the List provided. The Listname has to correspond to a Name attribute of one of the KpointLists.
The List of k-points
You might have different k-point sets in your setup, these KpointList XML elements are included into an outer KpointLists tag. Usually, the inpgen will generate multiple sets of k-points initially. With further calls to inpgen you might create further sets.
A Kpointlist is defined with the following attributes:
Attribute Desciption
Name Name of the k-point set to be used in Kpointlistselection. (required)
Count Number of k-points in the set. (optional)
type Description of the type: at present one of mesh,path,tria-bulk,tria,SPEX-mesh,unspecified (optional)
nx,ny,nz Size of the mesh in three spatial directions. (optional)
nkq_pairs Pairs of k,q vectors in a hybrid calculation. (optional)
Each kPoint element features the attribute weight and three numbers. The weight is the weight of the $\vec{k}$ point in the Brillouin zone integration. Each of the three numbers is divided by the value of the posScale attribute of the kPointList element to obtain the coordinates of the $\vec{k}$ point. In addition a label can be provided for use in bandstructure calculations. | {"extraction_info": {"found_math": true, "script_math_tex": 3, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.27934855222702026, "perplexity": 4324.0063894133555}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030335254.72/warc/CC-MAIN-20220928113848-20220928143848-00254.warc.gz"} |
http://www.askamathematician.com/2011/08/q-why-does-light-choose-the-path-of-least-time/ | # Q: Why does light choose the “path of least time”?
Physicist: Light travels at different speeds in different materials. When you shine a beam of light from one material into another (like from air to water) it bends in such a way that the path it takes from one point to another requires the least possible time.
Taking a straight line means traveling through a lot of the “slow material”. Traveling through lots of “fast material” to make the path through the slow material as short as possible means taking a longer path overall (and taking more time). The path of “least time” is in between.
This should come across as deeply spooky. A particle that somehow “scouts the future” and then picks the fastest path to get where it’s going seems impossible.
And to be fair: it is. The crux of the problem is (as with damn near everything) wave/particle-ness. Particles can’t magically know what the shortest path will be, but waves find it “accidentally” every time.
First, check out the path that the “principle of least time” carves out. What follows is math, which some people dig. If you skip over the block of calculations, you won’t really miss anything.
The time, T, that it takes to traverse a path is D/V, where D is the length of the path and V is the speed.
$T = \frac{D_1}{V_1}+\frac{D_2}{V_2} = \frac{1}{V_1}\sqrt{a^2+x^2}+\frac{1}{V_2}\sqrt{b^2+(c-x)^2}$
The picture for the derivation below. In the top material the wave speed is “V1” and in the bottom “V2”. With a little calculus, by sliding x back and forth you can find the “minimum-time path”.
By changing x you change the path, and the amount of time T it takes to move along that path. Calculus wonks may know that to find an “extremum” (either a maximum or a minimum), all you have to do is find the derivative, set it to zero, and solve. With any luck, those same wonks will be forgiving if I just declare that the following derivation finds the minimum time (and not a maximum or something) instead of proving that it’s a minimum.
$\begin{array}{ll}0=\frac{dT}{dx}\\\Leftrightarrow 0=\frac{d}{dx}\left[\frac{1}{V_1}\sqrt{a^2+x^2}+\frac{1}{V_2}\sqrt{b^2+(c-x)^2}\right]\\\Rightarrow 0=\frac{1}{V_1}\frac{1}{2\sqrt{a^2+x^2}}(2x)+\frac{1}{V_2}\frac{1}{2\sqrt{b^2+(c-x)^2}}(-2(c-x))\\\Leftrightarrow 0=\frac{1}{V_1}\frac{x}{\sqrt{a^2+x^2}}-\frac{1}{V_2}\frac{c-x}{\sqrt{b^2+(c-x)^2}}\\\Leftrightarrow \frac{1}{V_2}\frac{c-x}{\sqrt{b^2+(c-x)^2}}=\frac{1}{V_1}\frac{x}{\sqrt{a^2+x^2}}\\\Leftrightarrow \frac{1}{V_2}\frac{c-x}{D_2}=\frac{1}{V_1}\frac{x}{D_1}\\\Leftrightarrow \frac{1}{V_2}\sin{(\theta_2)}=\frac{1}{V_1}\sin{(\theta_1)}\end{array}$
The angles for the last step above. This is also “Snell’s law”.
The exact value of x isn’t particularly useful. What is useful are those angles. The statement “$\frac{1}{V_2}\sin{(\theta_2)}=\frac{1}{V_1}\sin{(\theta_1)}$” is Snell’s law.
Snell’s law should look familiar to anyone whose used to talking about waves going from one material to another. It describes, for example, the bending of light as it crosses between air and water.
So, the law of “least propagation time” is nothing more than a different, and far more difficult, way of stating “Snell’s law”. And again, if you’re talking about a particle, it’s hard not to think that the particle is testing each path in advance, and then taking the quickest one.
However, you can derive the same result by thinking about how waves propagate. Waves (light, sound, water, whatever) propagate perpendicular to their wave crests. Take a second: picture an ocean wave.
As one side of the crest enters a different material it changes speed. When different parts of the wave are traveling at different speeds the wave front as a whole changes direction.
Top: a section of the wave starts to hit the boundary between two materials. Middle and Bottom: In the second material the wave moves slower. Since one side of the wave is moving faster than the other the wave front “swings around” into a new direction.
A good (but not quite accurate) way to picture the situation is to think of a car where the wheels on one side spin faster than the wheels on the other. Naturally, the car’ll turn to the side.
Left: the important angles, and where they show up in the triangles. Right: the angles and lengths involved in the math below.
You can be a bit more exact about this. The diagrams above describe a piece of the wave crest from the moment when one side hits the boundary, to the time the other side hits. Call that time “T” (why not?).
The distance that the top end of the piece-of-crest travels is D1 = V1T, and the distance the bottom tip travels is D2 = V2T. Now, using the definition of sine: $\sin{(\theta_1)}=\frac{D_1}{L}$ and $\sin{(\theta_2)}=\frac{D_2}{L}$.
Combining these you get:
$\begin{array}{ll}\frac{1}{D_1}\sin{(\theta_1)}=\frac{1}{L} = \frac{1}{D_2}\sin{(\theta_2)}\\\Rightarrow\frac{1}{V_1T}\sin{(\theta_1)}=\frac{1}{V_2T}\sin{(\theta_2)}\\\Rightarrow\frac{1}{V_1}\sin{(\theta_1)}=\frac{1}{V_2}\sin{(\theta_2)}\end{array}$
Holy crap! Snell’s law again! Having the same result means that, in terms of behavior, the two approaches are indistinguishable. So, instead of a spooky particle scouting every path looking for the quickest one, you have a wave that’s just doing it’s thing.
The principle of least time is a cool idea, and actually makes the math behind a lot of more complicated situations easier, but at it’s root is waviness.
This entry was posted in -- By the Physicist, Equations, Geometry, Logic, Physics. Bookmark the permalink.
### 15 Responses to Q: Why does light choose the “path of least time”?
1. Rick says:
I have heard something like this explained as a principle of least action, where “action” refers to a highly abstract physical notion.
http://en.wikipedia.org/wiki/Principle_of_least_action
2. The Physicist says:
That’s the “more complicated situation” I was thinking of.
3. Rick R says:
I made a flash animation showing path selection via Fenman’s arrows method.
5. Dan says:
Thank you so much posting this. I knew about the principle of least time and I knew about Snell’s law, but I never made the connection before.
6. Stephen says:
How does this prove that one of the theories is more correct than the other?
Just because we don’t know how a particle would be able to take every path simultaneously, we also don’t know why the wave crest would actually turn. Because this isn’t a water wave, and the wave crest itself isn’t physical – it’s the imagined barrier of all of the photons on the front of the light beam. We know of no reason why these photons would link together.
The math works for both, but the only on with any actual experimental evidence that supports it is the path of least action – the evidence being the double slit experiment.
The path of least time sounds pretty unbelievable, but so do many things we now know to be true in modern physics.
7. John Cabbage says:
I have always disliked the “path of least time” argument, because it doesn’t easily relate to any physical principal.
As you showed here, Snell’s Law is easily derived from the wave model of light. The “path of least time” thing, however, frequently feels like more of a happy coincidence than a physical law.
As a counter example, consider a coherent laser beam that I fire into a material with a VERY high index of refraction (so it causes the laser to move extremely slowly). It would always make the time shorter if the laser beam somehow bent around the material instead of going through it. But it doesn’t, it flies straight ahead because that’s what lasers do.
Thus, the path of least time has always seemed like an odd condition that just happens to work in certain constructed circumstances.
8. Angelo says:
This might be a silly question, but why has the size of the wave front gotten bigger (stretched) as light traveled from one medium to the other?
9. Robin Smith says:
The principle of least time at first seems strange to those accustomed to living in a three-dimensional Euclidean space whom usually experience only small relative velocities between objects in their surroundings (us), and thus don’t have a day-to-day experience of the four-dimensional space-time in which they actually live.
However, a photon very much lives in the four-dimensional Minowski space-time that we don’t usually experience, because it’s moving at the speed of light. As such, you would expect even slight disturbances in this fourth (time) dimension to have a real effect on the path of a photon through its four-dimensional Minowski space. Sending the photon along the shortest Euclidean path may be sort of be like ‘forcing’ the photon to go up a four-dimensional hill instead of around it.
This to my mind makes just as much intuitive sense as the way a planet ‘knows’ which path to fall along as it orbits around another body (which has caused the spacetime around it to become curved), without having to actually try all of the possible paths, in order to minimise its path through that curved space. In this case, we are noticing the curvature of space more than a curvature of time. So why should not a photon take the path that it does between two points in order to minimise the time that it takes? When you stick a piece of glass in a photon’s path, you’re altering its speed dramatically (as projected onto our reference frame). You’re altering significantly the space through which it travels, particularly in the photon’s time dimension.
That’s the analogy i like to make.
10. Anders says:
Hi,
thank you for an interesting post, which I have just stumbled upon.
I have a question ( – I realise that the post is a year old…):
In your wave-argument you have a drawing of a wave entering another material. This gives rise to 2 triangles.
1. The upper triangle is simply defined to be a “right triangle”.
2. The bottom triangle is drawn as also forming a 90 degree angle. Is this per assumption of the refraction, or can it somehow be inferred (without reference to Snell’s law, or the Principle of least action…)?
11. c walsh says:
Could anyone please give me an expression for x?
referring to the first diagram
n=v1/v2
This means solving for x in
x^2/(a^2 +x^2)=(n^2*(c-x)^2)/((b^2 +(c-x)^2))
12. rob reede says:
I really, really like that you give the two approaches back to back, for contrast. I am not a physicist—–just a teacher. I like to see things put in a manner described by Denzel Washington, in “Philadelphia” : “……I need you to explain the whole thing to me, as if I were a six yr old” No gross assumptions.
If you can clear up, for me, WHY you introduced the idea of dT/dx, right after drawing the triangles , it would help. I think I know, but still it would be good to see it. I understand what the derivative does, but how it plays into the greater derivaTION is the burning interest to me.
Sorry if I sound too elementary.
Thanks !
13. The Physicist says:
@rod reede
Thanks!
There are a lot of paths, and the only difference between them is the parameter x, the location where the path crosses through the surface. By setting $\frac{dT}{dx}=0$ we figure out what values of x correspond with extreme values of T. Those x’s tell us which paths that takes the least or greatest amount of time. There’s no longest path, since you can just slide x to the right or left forever (to create arbitrarily long paths), so the one critical value of x is a minimum.
Alternatively, you could do it right and use a derivative test. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 7, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8242647647857666, "perplexity": 728.8085886917725}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806736.55/warc/CC-MAIN-20171123050243-20171123070243-00767.warc.gz"} |
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Satnoianu, R. A. and Maini, P. K. and Menzinger, M. (2001) Parameter domains for Turing and stationary flow-distributed waves: I. The influence of nonlinearity. Physica D, 160 (1-2). pp. 79-102.
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Crampin, E. J. and Maini, P. K. (2001) Reaction-diffusion models for biological pattern formation. Methods and Applications of Analysis, 8 (3). pp. 415-428.
Satnoianu, R. A. and Maini, P. K. and Sánchez-Garduño, F. and Armitage, J. P. (2001) Travelling waves in a nonlinear degenerate diffusion model for bacterial pattern formation. DCDS B, 1 (3). pp. 339-362.
Joyce, Dominic (2001) U(1)-invariant special Lagrangian 3-folds I. Nonsingular solutions. Advances in Mathematics . (In Press)
Joyce, Dominic (2001) U(1)-invariant special Lagrangian 3-folds II. Existence of singular solutions. Advances in Mathematics . (In Press)
Breward, C. J. W. and Darton, R. C. and Howell, P. D. and Ockendon, J. R. (2001) The effect of surfactants on expanding free surfaces. Chemical Engineering Science, 56 . pp. 2867-2878.
Heath-Brown, D. R. (2001) The largest prime factor of . Proceedings of the London Mathematical Society (3), 82 . pp. 554-596.
Roose, T. and Fowler, A. C. and Darrah, P. R. (2001) A mathematical model of plant nutrient uptake. J. Math. Biol., 42 . pp. 347-360.
Page, K. M. and Maini, P. K. and Monk, N. A. M. and Stern, C. D. (2001) A model of primitive streak initiation in the chick embryo. Journal of theoretical Biology, 208 (4). pp. 419-438.
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https://www.shaalaa.com/question-bank-solutions/two-dice-are-thrown-together-probability-that-least-one-will-show-its-digit-greater-3-a-1-4-b-3-4-c-1-2-d-1-8-random-experiments_57239 | Department of Pre-University Education, KarnatakaPUC Karnataka Science Class 11
# Two Dice Are Thrown Together. the Probability that at Least One Will Show Its Digit Greater than 3 is (A) 1/4 (B) 3/4 (C) 1/2 (D) 1/8 - Mathematics
MCQ
Two dice are thrown together. The probability that at least one will show its digit greater than 3 is
• 1/4
• 3/4
• 1/2
• 1/8
#### SolutionShow Solution
3/4
When two dice are thrown, there are (6 × 6) = 36 outcomes.
The set of all these outcomes is the sample space, given by
S = (1, 1) , (1, 2), (1, 3), (1, 4), (1, 5), (1, 6)
(2, 1) , (2, 2), (2, 3), (2, 4), (2, 5), (2, 6)
(3, 1) , (3, 2), (3, 3), (3, 4), (3, 5), (3, 6)
(4, 1) , (4, 2), (4, 3), (4, 4), (4, 5), (4, 6)
(5, 1) , (5, 2), (5, 3), (5, 4), (5, 5), (5, 6)
(6, 1) , (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)
i.e. n(S) = 36
Let E be the event of getting at least one digit greater than 3.
Then E = {(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6), (4, 1) , (4, 2), (4, 3), (4, 4), (4, 5), (4, 6),
(5, 1) , (5, 2), (5, 3), (5, 4), (5, 5), (5, 6), (6, 1) , (6, 2), (6, 3), (6, 4), (6, 5), (6, 6) }
∴ n(E) = 27
Hence, required probability = $\frac{27}{36} = \frac{3}{4}$
Is there an error in this question or solution?
#### APPEARS IN
RD Sharma Class 11 Mathematics Textbook
Chapter 33 Probability
Q 2 | Page 71 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.22710518538951874, "perplexity": 103.05768748487998}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038878326.67/warc/CC-MAIN-20210419045820-20210419075820-00412.warc.gz"} |
http://mathhelpforum.com/differential-geometry/86930-fundamental-group-question.html | # Math Help - Fundamental Group Question
1. ## Fundamental Group Question
What is $\pi_1(S^1 \vee S^1 \vee S^2)$?
Is it $\mathbb{Z} * \mathbb{Z} * \{1\}$ by Van Kampen's Theorem?
Thanks, I just wanted to check this.
2. Yes, that is correct. It is a free abelian group on two generators.
3. Originally Posted by Erdos32212
What is $\pi_1(S^1 \vee S^1 \vee S^2)$?
Is it $\mathbb{Z} * \mathbb{Z} * \{1\}$ by Van Kampen's Theorem?
Thanks, I just wanted to check this.
Yes.
Since $S^2$ is simply connected, $\pi_1(S^1 \vee S^1 \vee S^2) \cong \mathbb{Z} * \mathbb{Z}$.
The free product of a free group $\mathbb{Z}$ and a free group $\mathbb{Z}$ is a free group having a presentation $\{\alpha, \beta\}$, where $\alpha$ = 1 or -1 in the first $\mathbb{Z}$ and $\beta$ = 1 or -1 in the second $\mathbb{Z}$.
For instance,
$1_1 1_1 1_1 1_2 1_2$ (followed by a member in the first group) .... ,
reduces to
$3_1 2_2 ...$ ,
where $x_i$ denotes the element x in the i-th $\mathbb{Z}$, i=1 or 2, and the group operation between elements in the same group is an addition.
As you know, $\mathbb{Z} * \mathbb{Z}$ and $\mathbb{Z} \times \mathbb{Z}$ are two different things. The former is non-abelian because a free group on a nonempty set S is abelian iff S has exactly one element. The latter group is abelian, which is isomorphic to the fundamental group of a torus having a presentation $\{\alpha, \beta\ | \alpha\beta\alpha^{-1}\beta^{-1}=1\}$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 20, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7725234031677246, "perplexity": 218.4180007119529}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207930895.88/warc/CC-MAIN-20150521113210-00197-ip-10-180-206-219.ec2.internal.warc.gz"} |
https://cirq.readthedocs.io/en/stable/generated/cirq.Simulator.html | # cirq.Simulator¶
class cirq.Simulator(*, dtype: Type[numpy.number] = <class 'numpy.complex64'>, seed: cirq.RANDOM_STATE_OR_SEED_LIKE = None)[source]
A sparse matrix wave function simulator that uses numpy.
This simulator can be applied on circuits that are made up of operations
that have a _unitary_ method, or _has_unitary_ and
_apply_unitary_, _mixture_ methods, are measurements, or support a
_decompose_ method that returns operations satisfying these same
conditions. That is to say, the operations should follow the
cirq.SupportsConsistentApplyUnitary protocol, the cirq.SupportsUnitary
protocol, the cirq.SupportsMixture protocol, or the
cirq.CompositeOperation protocol. It is also permitted for the circuit
to contain measurements which are operations that support
cirq.SupportsChannel and cirq.SupportsMeasurementKey
This simulator supports three types of simulation.
Run simulations which mimic running on actual quantum hardware. These
simulations do not give access to the wave function (like actual hardware).
There are two variations of run methods, one which takes in a single
(optional) way to resolve parameterized circuits, and a second which
takes in a list or sweep of parameter resolver:
run(circuit, param_resolver, repetitions)
run_sweep(circuit, params, repetitions)
The simulation performs optimizations if the number of repetitions is
greater than one and all measurements in the circuit are terminal (at the
end of the circuit). These methods return TrialResults which contain both
the measurement results, but also the parameters used for the parameterized
circuit operations. The initial state of a run is always the all 0s state
in the computational basis.
By contrast the simulate methods of the simulator give access to the
wave function of the simulation at the end of the simulation of the circuit.
These methods take in two parameters that the run methods do not: a
qubit order and an initial state. The qubit order is necessary because an
ordering must be chosen for the kronecker product (see
SparseSimulationTrialResult for details of this ordering). The initial
state can be either the full wave function, or an integer which represents
the initial state of being in a computational basis state for the binary
representation of that integer. Similar to run methods, there are two
simulate methods that run for single runs or for sweeps across different
Parameters
• simulate (circuit, param_resolver, qubit_order, initial_state) –
• simulate_sweep (circuit, params, qubit_order, initial_state) –
The simulate methods in contrast to the run methods do not perform repetitions. The result of these simulations is a SparseSimulationTrialResult which contains, in addition to measurement results and information about the parameters that were used in the simulation,access to the state via the state method and StateVectorMixin methods.
If one wishes to perform simulations that have access to the wave function as one steps through running the circuit there is a generator which can be iterated over and each step is an object that gives access to the wave function. This stepping through a Circuit is done on a Moment by Moment manner.
simulate_moment_steps(circuit, param_resolver, qubit_order,
initial_state)
One can iterate over the moments via
for step_result in simulate_moments(circuit):
# do something with the wave function via step_result.state
Note also that simulations can be stochastic, i.e. return different results for different runs. The first version of this occurs for measurements, where the results of the measurement are recorded. This can also occur when the circuit has mixtures of unitaries.
See Simulator for the definitions of the supported methods.
__init__(*, dtype: Type[numpy.number] = <class 'numpy.complex64'>, seed: cirq.RANDOM_STATE_OR_SEED_LIKE = None)[source]
A sparse matrix simulator.
Parameters
• dtype – The numpy.dtype used by the simulation. One of numpy.complex64 or numpy.complex128.
• seed – The random seed to use for this simulator.
Methods
compute_amplitudes(program, bitstrings[, …]) Computes the desired amplitudes. compute_amplitudes_sweep(program, …[, …]) Computes the desired amplitudes. run(program[, param_resolver, repetitions]) Samples from the given Circuit. run_async(program, *, repetitions) Asynchronously samples from the given Circuit. run_sweep(program, params[, repetitions]) Runs the supplied Circuit, mimicking quantum hardware. run_sweep_async(program, params[, repetitions]) Asynchronously sweeps and samples from the given Circuit. sample(program, *[, repetitions, params]) Samples the given Circuit, producing a pandas data frame. simulate(program[, param_resolver, …]) Simulates the supplied Circuit. simulate_moment_steps(circuit[, …]) Returns an iterator of StepResults for each moment simulated. simulate_sweep(program, params[, …]) Simulates the supplied Circuit. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6306428909301758, "perplexity": 2403.5033648987915}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400205950.35/warc/CC-MAIN-20200922094539-20200922124539-00632.warc.gz"} |
https://math.stackexchange.com/questions/3428259/nbg-set-theory-and-the-axiom-regularity | # NBG set theory and the axiom regularity
In E. Mendelson's book 'Introduction to Mathematical Logic' he develops NBG set theory. I believe it's well-known enough that a description here is not needed. Althought it could not hurt to summarise the main points:
• The objects of NBG are classes and sets are defined as classes which are members of another class,
• NBG is a conservative extension of ZF,
• NBG and ZF are equiconsistent.
When Mendelson formulates the axiom of regularity though he essentially states it as "Every class is well-founded". Why does he not formulate it as "Every set is well-founded"? They seem (unless I am mistaken) to be equivalent in $$\mathbf{NBG}+\mathbf{AC}$$ but I'm unsure otherwise.
You're right, they are equivalent. Using the axiom of choice (in particular, dependent choice), you can show that the axiom of regularity holds if and only if there are no infinite descending sequences under the $$\in$$ relation (I can provide a proof if desired). If regularity did not hold for classes, then we would have a sequence of classes $$\ldots x_2\in x_1\in x_0$$ However, by Mendelson's definition of a set, all but $$x_0$$ are sets, so we have the sequence of sets $$\ldots x_3\in x_2\in x_1$$ which means regularity does not hold for sets. Thus, if all sets are well-founded, then all classes must be well-founded. I'm guessing he formulated the axiom of regularity in terms of classes simply because the axioms are meant to establish the properties of classes, and consequently, sets as well.
Suppose all sets are well-founded and let $$C$$ be a nonempty class. Let $$x\in C$$. If $$x\cap C=\emptyset$$, then $$C$$ is well-founded. If $$x\cap C\neq\emptyset$$, then $$TC(x)\cap C\neq\emptyset$$ where $$TC(x)$$ denotes the transitive closure of $$x$$ (the fact that the transitive closure of $$x$$ exists and is a set is true in NBG without the axiom of regularity, as can be seen in my proof here). Since $$TC(x)\cap C\subset TC(x)$$ and $$TC(x)$$ is a set, so is $$TC(x)\cap C$$. So by assumption, there exists $$y\in TC(x)\cap C$$ such that $$y\cap TC(x)\cap C=\emptyset$$. Assume $$z\in y\cap C$$. Then, since $$z\in y\in TC(x)$$ and $$TC(x)$$ is transitive, $$z\in TC(x)$$ so that $$z\in y\cap TC(x)\cap C$$, a contradiction. So, $$y\cap C=\emptyset$$ and hence, $$C$$ is well-founded. Thus, all classes are well-founded if and only if all sets are well-founded.
• @Anonymous The argument is that if $C$ is a nonempty class and $y\in C,$ then either $y$ is $\in$-minimal in $C$, in which case we're done, or $trcl(y)\cap C$ is a nonempty set whose $\in$-minimal element is necessarily $\in$-minimal in $C$ since $trcl(y)$ is transitive. – spaceisdarkgreen Nov 10 '19 at 6:41
• @Jean-PierredeVilliers I made an edit to my answer which builds on the argument spaceisdarkgreen mentioned. Note that $trcl(y)$ is the smallest transitive set that containing $y$. It is not the intersection of all transitive sets in $C$ containing $y$ since $C$ need not even contain any transitive sets. I also linked to a rigorous proof in my edit for the existence of the transitive closure. The proof I linked to does not use any axiom of choice or axiom of regularity, and is valid in the context of NBG. – Anonymous Nov 10 '19 at 17:32
• @Jean-PierredeVilliers I think Anonymous has covered it in their edit. The $trcl(y)$ is just the smallest transitive set with $y$ as a subset, irrespective to being in $C,$ and it won't generally be in $C$ (and doesn't need to be for the argument to work). – spaceisdarkgreen Nov 10 '19 at 17:40 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 26, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9768761992454529, "perplexity": 139.4524393730658}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875143079.30/warc/CC-MAIN-20200217175826-20200217205826-00123.warc.gz"} |
https://physics.meta.stackexchange.com/questions/5664/reputation-display | # Reputation display
I just got an announcement that by getting 2000 rep, I can edit questions and answers without review. The title bar shows my rep as 1990. I clicked on my icon in the title bar to see if that would cause an update, but it didn't. It is probably a difference in update times for the different pieces of the site, but it has persisted for a while. More amusement than a real problem.
• Presumably someone voted for you, triggering the announcement, then retracted the vote. Mar 31 '14 at 5:50
• @Emilio explained it well
– m0sa StaffMod
Mar 31 '14 at 11:19
• @m0sa quick note - that didn't ping me. Apr 1 '14 at 11:02
• @Emilio it only pings you once you've participated in that particular post's comment thread (like now)
– m0sa StaffMod
Apr 1 '14 at 11:43
• @m0sa I know. I was just wondering why you used it. Apr 1 '14 at 12:34
Votes can be retracted within the first five minutes after they're cast, in which case they do not show up in your reputation history. They can also be retracted if the post is edited, in which case you will get a corresponding -10 on your reputation history, with the explanation unupvote. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.36845749616622925, "perplexity": 1970.723407386424}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320300574.19/warc/CC-MAIN-20220117151834-20220117181834-00697.warc.gz"} |
http://blogs.thescore.com/djf/2013/10/03/leadership-early-exits-and-don-cherry/ | ## Leadership, Early Exits, And… Don Cherry?
There was a real delicious bit of red meat for the mouth-breathers at the end of Bob Elliott’s piece in the Toronto Sun from late Sunday, which was ostensibly about Darren Oliver’s final moments in a big league uniform. While the nice thing for us to do would be to not just skip over the whole capping-off-a-great-career bit, who can get all maudlin about Black Magic riding off into the sunset when you read a thing like this?:
“I’ll tell you what the GM needs to do for next year, he needs to go get some grinders, some guys who want to play,” one player said. “Look around at all the these empty lockers. I’m no doctor but you can’t tell me all of these guys are so injured or all in Florida re-habbing that they can’t stay for the final weekend of the season.”
Empty lockers on the final weekend included Edwin Encarnacion (who had wrist surgery), Jose Bautista (currently treating his hip in Dunedin by jogging underwater), Melky Cabrera (knee, back surgery), Brett Cecil (elbow), Maicer Izturis (ankle), Josh Johnson (forearm), Brandon Morrow (forearm) and Colby Rasmus (hit in the eye last week at Fenway Park).
I’ll tell you who can’t get maudlin (unless, that is, you’re referring to his Sammy Maudlin-esque wardrobe*): Don Cherry.
Yes, everyone’s favourite incoherent, (formerly?) xenophobic, drunk uncle-like hockey commentator apparently couldn’t pass up the opportunity to keep pushing his pro-grinder agenda, while also taking a giant bit of poetic license about the source of the quote and what it supposedly tells us.
Oh yeah, if you weren’t previously aware, uh… Grapes hasn’t quite got the hang of Twitter’s format just yet.
Regardless, as anybody who remembers the pre-chorus to Lunchlady Land** knows, “grinder” is hardly an exclusively Canadian word. Of course, that’s a “grinder” of a different sense, but a cursory Google search shows that it’s used in poker, in video games, and other places in the same sense as hockey term we’re all familiar with.
But, of course, even if were exclusively a Canadian word, that would hardly mean that Sherlock Holmes here has cracked open the case. I mean, it’s not like these guys who play for the Toronto Blue Jays are entirely inexperienced with the words of Canada.
Hey, but who needs logic when you can see a list that’s half made up of four Dominicans who either signed here of their own volition, or chose to re-sign with the club and forgo a possibly more lucrative trip through free agency, and then suggest that they just plain don’t want to be in Canada for a single second longer than necessary.
Of course, I’m falling exactly into a trap by bothering to take anything that Cherry says seriously.
But the Elliott piece warrants attention… maybe. Nothing will get hopeless dolts talking out their asses faster than an invitation to discuss their fairy tale understanding of a nebulous concept they call “leadership,” and it’s always good to push back at that. But this, like yesterday’s hubbub over a player telling Jeff Blair that Jose Bautista’s histrionics with umpires was “a distraction”– which, naturally, led to hilariously asinine suggestions of Bautista and his spirit of entitlement overtaking the team and ruining the careers of Ricky Romero and J.P. Arencibia, who just can’t let themselves listen to instruction because big, bad Jose put it into their minds that they’re special little perfect snowflakes who should always get their way– is really grasping.
There certainly isn’t the panache of clubhouse mutinies past in these reports. Which doesn’t mean that they’re false, but it’s so easy for them to get incredibly overblown. Maybe they’re not, but maybe consider that it could have been the same player speaking to both Blair and Elliott, and he may have an agenda of his own. We have no idea.
We only know the basic facts: one, or maybe two, players told Blair that Bautista’s complaining to umpires was a distraction. This doesn’t necessarily mean they were clouded with rage and unable to operate their brains because of how badly they wanted to punch him in the face, it just means it was a distraction; maybe it became too much of drain on focus as it overtook the dugout chatter, or… who knows? What we do know is that, as far as our information goes, this is only one person’s opinion, and that it is in reference to a small component of the relationship between Bautista and his teammates, the rest of which we have zero idea about.
Then we have Elliott’s player– who clearly isn’t Lawrie, which I think is obvious by the use of “I’m no doctor” and the lack of “getttittt” or the liberal use of “bro”– whose point is… odd. These injured players should be here for some meaningless games just to sit on the end of the bench trying to not get more hurt? The guy with the spinal tumour and the one who just was in the hospital after getting hit in the face aren’t grinders by not being there? Bautista, who tried his damnedest to come back from last year’s wrist injury, returning for two August games before having to shut it down, doesn’t want to play? Encarnacion, who at the end of a meaningless season was swinging the bat repeatedly in obvious, hard-to-watch pain, isn’t a grinder? Josh Johnson, who still had elbow pain when he visited Dr. James Andrews this week, and so immediately went under the knife, didn’t want to play? Brandon Morrow, who is under doctors orders not to throw until mid-October, doesn’t want to play?
Shit, I hope it wasn’t Brett Lawrie making those sorts of suggestions, because it sounds to me like whoever did, maybe he’s the problem.
But, of course, no matter how silly or petty or easily dismissed it all is, for some it’s all going to feed back into the leadership fairy tale– you know, the one full of war metaphors and players having little to no agency of their own over their own careers and lives? It’s just demeaning and lazy to look at it through that prism and to try to divine moral characteristics of certain men in the tiny amount of time we view them on our TV screens each week. And it’s just not reality.
Yes, leadership is thing– obviously– but the perception I think a lot of fans have of the locker room dynamic is just kinda silly. I don’t expect that everyone has worked with an ex-clubbie or spoken regularly to people who are always down at the park, but has no one read Dirk Hayhurst or Ball Four? There is a diversity of personalities, weird characters, all kinds of complex relationships and things going on, none of which we should have the fucking gall to believe we understand in the slightest from where we sit– especially when believing one thing or another is so often dependent on pre-existing assumptions or on the desperate need to find any sort of flimsy explanation of blame and escape the scawwy horribleness of the unknown.
Fans get egged into this kind of stuff by a media that pretends it sees the ghosts, too. Let’s maybe just give it all a rest.
Besides… I dunno, I’m not seeing a whole lot of tension:
*That one’s for the olds, FYI.
** That one too, probably, now that I think of it.
Image via Best Of Toronto.
1. I’m no doctor but……well then stop right there Don.
2. Ill add this to the conversation. All this talk about Bautista equating negative locker room presence by all the journalists in town (including the uninformed hockey ones too) means that Rogers probably wont be hanging their hat on him when they develop the new promos for next year. Too much negativity surrounding him now in the Toronto sports media.
• I doubt it’s noticed much except by those of us paying very close attention. I think he’s still the most recognizable face on the team, and so wouldn’t expect much change there, personally.
3. Maybe it was a distraction because the damn newspapers and media won’t stop talking about it as if it had some meaning beyond ???. Therefore, it doesn’t distract on the field of play. It doesn’t distract clubhouse atmosphere. It amounts to a distraction like a fly is a distraction to you on the beach.
4. Oh, fun, a guessing game? Okay, Cherry already picked Lawrie as the clubhouse anonymous gossip. Do we all get a pick? Dibs on JPA!
• JP’s probably a good guess, what about DeRosa?:
• No DeRosa is old – he understands this stuff. JP is already at war with the media – he wouldn’t feed their fire.
It’s Lind. \$10,000 it’s Lind.
• If I didn’t think we’ll never find out, making the bet pointless, I’d take this bet in a heartbeat. Since you’re so sure, would you give me 2:1 if I put my 10K on Janssen?
• It was definitely my J.P
• Definitely Lind.
5. Cherry’s rant was stupid, but you’re missing the point. There are clearly chemistry issues on this team. I don’t say that because guys weren’t there for the final series. I say that because someone on the team complained about guys not being there for the final series. Also because players have complained about the umpire bitching. Whether you agree with their complaints or not (and who the fuck are you to tell ball players what they should or shouldn’t be pissed off about), the problem is that they’re complaining at all. Teams with chemistry, teams that like each other, teams that are one unit and not a collection of individuals DO NOT COMPLAIN TO THE MEDIA about these in-house issues. Clearly there’s a problem here. Maybe it was Brett who complained. Maybe it was Oliver. But who cares who it was? The point is that guys are complaining. Guys aren’t happy. And unhappy teammates don’t make for a good team.
• Guys aren’t happy after a total dog shit bomb of a season after they were supposed to be in the playoffs. SHOCKER!
• Or, rather than “guys” who are unhappy, it could be just one guy, bitching and moaning to every reporter he can find, and there’s no real story here whatsoever.
• You clearly missed the point of my talking about fairy tales.
And unhappiness means exactly zero. What gets referred to as “chemistry” is a byproduct of winning, not the other way around.
• But they’re not just unhappy about losing. They’re unhappy about players complaining to umpires and leaving the team early. This stuff doesn’t get discussed to the media if everyone in the room is on the same page. I’m not saying all the players have to like each other and hang out together away from the field. But they should at least respect each other enough to not complain to the media about each other.
• The media also specifically seeks out these kinds of stories during a season like this one (see: Boston Red Sox, 2011-2012).
• Yes…and once the source of the problem is shipped out (see: Beckett, Josh) the team can make a drastic turn around (see: Boston Red Sox 2013). Also, see: stop using this lame shtick.
The other thing that all this bubbles up from is that these guys are loose and they joke around and generally seem to enjoy the fact that they get paid ridiculous amounts of money to play a game for a living. Fans want them to sit there all stoic and pissed off if they arent winning, which is ridiculous. Fact is, if they were winning, the media narrative would be how both Joses keep the team loose and thats why they win.
Finally no one wants to admit just how much luck factors into professional sports. Its hard to find an edge when the difference between an effective player and a bad but still major league worthy player is razor thin. The margins of success are even thinner. This Jays team – the exact one that entered the season in April – could have won it all. They faced a Mr. Burns Company Softball Team’s worth of injuries. I believe Melky Cabrerra literally suffered from Botulism. Rasmus, Lawrie, Jose, Jose, EE, and Cabrerra all suffered significant injuries. No one could have predicted how horrible JP would be and their pitching staff? Dicky, Johnson, Happ and Morrow all had injuries.
My point is if youre going to lay the blame for the lack of success on leadership, you should at least be willing to lay some of the blame on something like the bad luck of injuries which is ACTUALLY QUANTIFIABLE.
• @Zaun
If the player complaining was doing so out of the purity of his leadership heart, he would have discussed this with Alex and the team – and we would never even hear of it.
The problem lies with the guy complaining.
• @ Sons – 100% bang-on. If a guy is willing to air these issues to the media, chances are he isn’t planning on being back next year, otherwise he wouldn’t risk being a pariah in the clubhouse. I’m thinking this might have just been Darren Oliver letting off some steam – he might have been upset that the injured Jays didn’t stick around to see him off in his last series as a player, especially after he put off retirement to come back to a team that was supposed to take him to the post-season for one last shot at a ring.
But yeah, I agree – if a guy come back the next year took issue with things going on in the clubhouse, it would be a private conversation with the manager/GM.
• Happy players don’t create winning teams. Winning teams create happy players.
6. My guess is JPA or Dickey, probably JPA though.
• My money’s on JPA. Dickey doesn’t strike me as the type of guy that would bitch about problems to the press. Hell, he’s been a problem for most of his career. JPA, on the other hand, was a mess this year and anything to distract the media from focusing on his disasterpiece of a season is great for him.
Besides, he only plays ball for himself and Jesus, right? Fuck the team.
• Yeah the more I think about it, I’m pretty sure it was JPA . I remember the comments he made with the dirk and zaun saga about those guys never coming down to the field level or clubhouse, just wreeks of JPA and can’t wait untill this bad baseball player is gone.
• my money is on JPA… I think he actually watches hockey.. doubt Brett Lawrie gives flying fuck.
7. “Hoagies and grinders, hoagies and grinders”
• Me too, haha.
• Can’t forget the navy beans and the meatloaf sandwich.
• When do they serve the sloppy joes?
8. I’m old enough for the first one.
And I’m too old for the second one.
Fuck I’m old.
9. Or maybe the player said it sarcastically as in that old joke about Jesus and the water-walking:
“Yeah, Jesus walked on water”
“Yeah, it was a distraction”
Or maybe the player was just musing possibilities, like:
“Yeah, maybe it could have been a distraction, I’ve never really put my mind to it”
10. I don’t even know which part of this bullshit fairy tale makes me most angry – o, no wait, I totally do: it’s the barely concealed undercurrent of racism that imbues all of these ridiculous stories.
Seriously people, our team is too immature and ‘doesn’t care enough’? Why don’t you just own up to it and say they suck because Sky Dome doesn’t have any grass for them to cut? Fuck people! The upper echelon of this team are all major league veterans with AT LEAST 5-10 years of major league experience. Reyes, Bautista and Encarnacion are as fucking personable as it gets. Bautista is too “fiery” with the umps but when Brian McCann acts like a troglodyte he’s just “grinding” and “standing up for his boys.”
Look, there were a lot of problems with the 2013 Jays beyond the injuries; Bonifactio and, tumor or no tumor, Melky Cabrera started the season VISIBLY out of shape and I don’t think it’s a coincidence that they were both terrible to start the year. The team, like last year, was 3 depth starters short in May when our injury prone starters got hurt. Our catcher completely forgot how to hit and Bautista had a pretty depressing visit from the regression fairy.
But if we’d started 14-5 in April Elliot’s dumb ass would have written about how we’re like Nationals North and how the loose atmosphere fostered by Gibby has allowed our veterans to take the lead and really create a family dynamic in the clubhouse. And Don Cherry would have forgotten that baseball even exists and just tweeted about Mike Zygomanis.
• *slow clap*
• Amazing post.
• Ray, you win the off season!
• Amazing post alright. Amazingly retarded.
The racist claim is bullshit. The difference between Bautista and McCann is that McCann stands up for his teammates, while Bautista stands up for himself. You don’t see Bautista bitching at the umpires because Edwin gets a bad call. It’s totally different.
I’m not saying there aren’t racist Jays fans though. That would be silly. There are lots of racist Jays fans. How else can you explain people liking Snider so much more than Thames? Or all the Cito hate? The Rajai jokes? Anybody who doesn’t fucking love the shit out of Kawasaki? But your grass cutting comment was the most racist thing I’ve seen on here in months. It would never cross my mind to make a comment like that, because I’m not racist.
• Change your name and you will be taken more seriously
• I’m going to go against my better judgement and answer this.
A) How often does the camera pan to Bautista after another player strikes out? You have literally no idea how he reacts.
B) It’s not specifically about Jays fans. It’s prevalent around baseball. When’s the last time you heard about a Latin American player described as a “scrappy, hard-working guy who gets the most out of his abilities”? (see also: Russian hockey players)
C) People hate Cito because he did stupid things as a manager.
D) What Rajai jokes have I been missing out on?
E) The people who love Kawasaki are the same people who loved Johnny Mac. Racist bastards.
• A) If he were complaining, the cameras would certainly point at him.
B) I agree. There are lots of racists out there.
C) Winning 2 World Series is stupid?
D) He’s lazy and dumb.
E) There are lots of people who loved Johnny Mac and dislike Kawasaki. I agree: Racist bastards.
• I’ve never once heard anyone call Rajai lazy. Not once.
Stealing third with two outs and Bautista up IS dumb.
What gives you the impression that Kawasaki isn’t loved in the same ‘glove-first futile hitter scrappy underdog’ way that Johnny Mac was? Listen to the ovations when he pinch hits.
And the lawn joke was satire, FFS.
• @Ray
Couldn’t agree more. I always go back to the Yunel incident. I encourage people to imagine fleeing an oppressive country and leaving behind family and friends. Going from a land where shampoo is special and new cars are 50 years old. Coming to a land with a language you don’t speak. A land full of people that will take a word of your language, translate it according to their own opinion of what it means and then decide that you intentionally sabotaged your own image to insult a group of people – even though you immediately state that you meant no offense.
Man the venom and rage that came out of Bob McCowan’s mouth for that. He was so utterly foaming and ridiculous that AA “dropped the call” and couldn’t get his signal back evidently.
I’m not trying to defend Yunel’s silly attempt at being clever with his eye black. But I’m saying there was very little attempt to understand Yunel or HIS culture. And plenty of people running him out of town.
And now there he is with the Rays, along with a rapist. And somehow they’ve overcome this to be a lot better team than the Jays.
• Yes…but the weird thing here is that the people on this website that were at the forefront of saying we should run Yunel out of town are the same ones now saying that the treatment of Bautista et. al. is racist.
• Which people?
• @Mark
There were many that saw it more seriously than I did – but it was not as venomous here as it was elsewhere. Of course 2 or 3 guys posting 5 times each can make it seem so.
11. WHY do we care what Don Cherry has to say about baseball? Hockey fans barely give a damn about him anymore.
I’m glad these players were given a rest and a head start on recuperating from injuries. 2013 was a disaster season and there’s zero point in having players “grind it out”, risking further injuries, when nothing can be accomplished.
12. Lawl, the pic at the end of the article is the best. love it. Btw who the fuck cares what Cherry has to say about baseball. Baseball aint hockey by a long shot.
13. I think the thing that sticks out to me, and has always struck me as odd, was why the Jays send their Major League players all the way to Florida to rehab? I suppose I understand why they’d send guys recovering from Tommy John, because of the facilities for throwing… But Bautista in Florida to run in a pool? Huh? They don’t have those types of facilities in Toronto? They sent Reyes to Florida as soon as it was time to end rest and start rehab.
I find it very strange. Don’t you want the guys around the team until its time to send them off. On assignments? We always hear from Hayhurst about the alienation guys feel when they’re on the DL bcs they’re not near their peers.
Don’t get it.
• There’s a rather good article about Jose wherein he talked about his experiences living in Toronto, I think it was for Toronto Life, and he explains, among other things, that there were problems with landlords and people breaking into his residence. With his family with him, he just didn’t feel safe. This is of course just wild speculation, but maybe his reason for rehabbing in Florida is more complicated than the proximity of pools vs. wanting to be around his teammates.
• Why Florida?
Probably a combination of things.
Firstly (and this is no order of importance, it’s my opinion) – they’ve got minor league training facilities there, with their own medical personnel…plus a more consistently warm climate throughout the year probably helps in rehabilitation, and getting back into some kind of game shape under real-life conditions.
14. When Jose Reyes laugh in the dugout, people complain that he’s not taking it seriously enough. When Jose Bautista gets pissed off about a bad call, people complain that he needs to calm down. When Colby Rasmus runs down the line, it looks effortless so people complain that he isn’t trying too hard. When Brett Lawrie runs down the line, he looks like he’s going to blow an artery, so people complain that he needs to tone it down a little.
This is what a season of shattered expectations will do to a fan base. If this all happened during a 90-win season, no one would care about any of these things.
15. Imagine if Don Cherry were the GM of this team. Just imagine.
16. Cherry is such a kook. What makes him so sure it wasn’t JPA who made the remark anyway? He fits Don’s idea of a ‘grinder’ too. He plays through lots of pain and all that gritty stuff. He’s just not “a good Canadian kid. *thumbs up*”
It’s well past time to send that man out to pasture.
17. MAYBE BASEBALL *SHOULD* BE MORE LIKE HOCKEY DID YOU GUYS EVER EVEN THINK OF THAT
18. The metric system is the tool of the devil! I get three rods to the hog’s head and that’s the way I likes it!!
Fucking Cherry.
Dominicans hate it here. Especially in the hayday when they all played here.
Everything Cherry says is nauseating. But the CBC loves their cash cow…..
19. This season was ruined the moment John Gibbons was hired to manage the Jays.
Ask Cleveland how important a manager is to guide a team to the post-season.
Ask Baltimore what a difference a good manager makes. Boston for that matter…
I honestly believe that had AA hired Sandy Alomar Jr, Dave Martinez or even just forced Farrell to honor his contract instead instead hiring Gibby… this season wouldn’t have been such a disaster. I think this team wasn’t able to gel because the manager was unable to control the locker room and get the best out of his players… period.
• Wow
• Troll much?
• Your mind works like that AND you share it with the world? You are a brave man.
• YOU’RE RIGHT! I mean shit, why didn’t we think of hiring John Farrell–oh wait. Wait, we did have him here… That’s right — managers aren’t magic! It’s almost like it has more to do with the team on the field than the guy in the ill-fitting pants.
20. First time i’ve seen the word volition used in context. Has someone been listening to new Protest the Hero?
21. I’m sorta reminded about last years BoSox.
Guys eating chickhen and drinking beer during a game and Francona gets fired.
Sox fans claimed if Farrell was there, it never woulda happened.
Farrell gets hired and Pedroia,Salty and Napoli go to Jays game on their off day.
According to Butterfield,this year unlike previous years,they do infield every day at home and every two days on the road,with all the vetrans buying into it.
Does that mean anything?
Are the Sox more focused on the prize?
Team dynamics and support produce more than individual goals and interests?
• never thought I’d do this for radar, but +1
loves me some fundamentals
• would anyone complain if the Jays put in this kind of work?
everyone would all be saying how much they liked it, so it’s not to say it’s irrelevant & inconsequential, we would love to have a team like that if we had one
• Even if it is a backhanded compliment, I’ll take it.
Just don’t let Stoeten see it.
LOL
• And so then what of the horseshit narrative about Francona magically making Cleveland great?
This nonsense all collapses under the tiniest scrutiny. It’s silly.
Where’s the Buttfield quote, by the way?
• @ Stoeten
Just posing the questions.
Did you see the question marks at the end of the sentences?
The Butterfield interview was conducted by Howarth the last time the Jays were in Boston.
Both Jerry and Jack have been on a mission,questioning the lack of fundamentals with the Jays.And Butterfield mentioned that all the vetrans had bought into the program.Jack was adamant that the repetition of infield everyday can do nothing but produce positives.
Don’t shoot me because they said it.I’m just repeating it.
Gotta go.
Interesting discussion.
Take care.
• If this is all true regarding the vets buying into infield practice, etc, does anyone out there happen to know if Butterfield did the same with the Jays when he was here?
This isn’t to advance any kind of argument, I’m just curious.
• I don’t believe that you’ve quoted him correctly, based on what Wilner had said about it, but I would have to listen myself.
22. Janssen?
23. stoeten – I can’t believe you are giving this nonsense the time of day…
the beat writers are trying to develop a narrative for the offseason.
you don’t get 25 testosterone fueled guys living in close proximity virtually every day for 6 months without guys getting on each others nerves. winning helps ease the tension… but that wasn’t the case in Toronto this year. end of story. the whole storyline is just background noise and doesn’t have anything to do with putting a winning team on the turf for next year.
the fact that blair thinks it is noteworthy that a player was somewhat annoyed by the antics of another player says more about blair than it does the state of the clubhouse.
• Well said. Those of us with wives can attest to the fact that no matter how much you love someone, they can still get on your nerves every now and then just due to the fact that you live with them and are often in close proximity to then. This is exacerbated if there is a frustrating situation brewing (getting lost while driving, tough financial situation, house in need of cleaning, etc).
Therefore, on a baseball team expected to do well and having the wheels fall off, it’s only natural that guys will get frustrated/pissed off/angry at others even with little or no provocation. Winning fixes a lot of the little things.
24. “Nothing will get hopeless dolts talking out their asses faster than an invitation to discuss their fairy tale understanding of a nebulous concept they call “leadership,” and it’s always good to push back at that. ”
OK. Can you name me a version of the Jays since 1993 that has had a ‘clubhouse leader’ or anything of that nature? The championship teams had plenty of them. And the veterans were known to get on the rookies if they thought they weren’t taking the game seriously enough. But since then, I can’t think of anyone. Delgado shied away from a leadership role I believe. So did Halladay.
And I can’t believe it’s a coincidence that, since that 1993 team broke up, we haven’t gone to the playoffs once.
• I don’t know if leadership the way you say they had in 92 and 93 is necessary or necessarily winning, but what I do know is that the reason they haven’t been to the playoffs since is that they haven’t been as good at baseball as the teams that have made it in. And it hasn’t even really been close, certainly not close enough that the extra couple of wins Winfield’s leadership, or whoever you have in mind, would have (dubiously) created would have been enough to put them in the playoffs.
• I don’t think it’s about some ‘leader’ emerging to bring the team to the promised land. To me, it’s more about the players’ expectations of each other, and an air of accountability that seems missing. ‘Leadership’ isn’t, on its face, a singular noun.
• This is a different thing. You specifically asked whether the Jays have had a clubhouse leader since 1993.
I don’t think we can know about accountability, but I don’t disagree with you about this – it seems to me as well that there is a lack of it. But I pin this more on management than on the players. For example, there were a couple of times when I would have liked to see JPA sent a message, most notably after his bum fight with the press – one would think that would have been a distraction.
Bautista deserved to be held to account for freaking out about being deprived an RBI when his hit was scored an error. But I don’t think guys of his stature are ever held accountable in the way we’re talking about.
Lawrie obviously deserved to be held accountable for yelling at Lind and Rivera. But it was my understanding that it was addressed. He had the one incident this year. There was a series of issues with Puig before he was sat down (by Mattingly) for something like 5 innings.
• Interestingly, if I recall correctly, Bautista did get involved in the Lawrie thing. He came into the dug-out yelling his head off, and Gibby sais something about ‘bullshit’ and then Bautista came along the row to calm Lawrie down. So he does take an interest in this kind of thing. You’re right, and I do sound like I’m asking for one leader. But I really don’t think it’s a question of one leader. I think the team needs a bunch of leaders from management and from the players themselves. Obviously Farrell has been able to do in Boston what he could not do here. And I think it might be a rewarding exercise to find out what he did differently–if anything–and what–if anything–we can learn from it.
• I really do think winning will breed the kind of thing you’re looking for. A “winning culture”, where everyone is expecting to win and expecting everyone to do everything to pull in that direction, and letting each other know about it and hear it when they’re not, I think this culture is created from winning consistently.
I’m not making excuses, but it is super annoying in a low-performing organization to have one or two people holding everyone accountable to a higher standard, when the resources just aren’t there. Even if Goins could play like Pedroia and getting there is just a matter of De Rosa getting in his ear after he strikes out, what difference does it make when you still have to rely on Happ/Rogers/Redmond, when you’re buried so deep due to injuries to key players and lack of depth and the GM not fixing the hole at 2B and Bonifacio and Izturis sucking so hard…
I think they can have that culture you seem to want. They have to get off to a better start, and it would help to have guys like Boegarts, Profar, Rios, Iglesias if they were to lose Lawrie or Reyes or another key player again. Then you’d see the club house showing the new guy what is expected of him and your desire for leadership would be fulfilled.
• What did Farrell do besides get hired by a better constructed team? Like, for fuck sakes, stop pretending this stuff you’re inventing means anything.
• I’m not suggesting Farrell did anything. And he certainly wasn’t a good leader here. But I am saying that maybe there were management-style things he did differently with the Sox and it’s worth seeing (a) if there were any and (b) if they could be worth implementing here. At this point if I were front office I would be examining *everything* with a very close lens to see if I could pin down everything that went wrong and to work out whether what did go wrong could have been prevented. A total mess like this last season is the kind of event that has a very long tail in a corporation.
• You have absolutely zero idea of who did what in that room, so your attempting to speak about it like you know is pretty ridiculous.
• Actually Stoeten,when Gillick was asked which was the best team he ever assembled for the Jays, the 92 or the 93 Jays?
He replied neither, the 91 team was superior to both.
He should know, he built them.
Then he went out and obtained Winfield.
Winfield rallied the team to 3 goals,1)winning the division,2) winng the AL,3) winning the WS.
Can you win without the talent? No
Did Winfield’s leadership help push them over the top?Can’t be quantified so nobody( including you) knows absolutely for sure,one way or the other.
• IT WAS HIS TALENT THAT HELPED, YOU DOPE! Are you fucking serious with this horseshit?
Plus, the ’91 team won their division. Short series’ are essentially crapshoots, so… holy shit, there is absolutely no rational reason to think that magical leadershippiness had anything to do with anything breaking the other way for the Jays in 1992. They were a very talented team, and things broke right.
• Jeez Stoeten,you sound pissed.
Sorry but I tend to give Gillick’s opinion a little bit more credibility than your’s.But I love your conviction.
BTW.I think he was in the locker room a little more than you were.
• Yeah. Winfield is the reason they wanted to win. No MLB player wants a World Series until a leader emerges to tell them championships are important. I guess Winfield’s spirit is what led to the ’93 championship.
• And that’s the problem. You really want to swallow whole hog the opinions of people who have reason to mythologize all that bullshit? If you don’t understand why someone in his position is unreliable, then… well, actually then I guess your cluelessness makes a little more sense.
Do you see why people like me have a problem with this? When you call it luck, you let EVERYBODY off the hook. Nobody is accountable for anything.
In your view, “players will play to their averages.” and “everybody has slumps”. It’s such an “Excel spreadsheet” way of looking at a very complex game, and it’s RIDICULOUS to deny the existence of things like chemistry, clutch and leadership.
• Yes, I see why you have a problem: you believe in ghosts and, based on your paraphrasing, can’t comprehend what I’m saying in the slightest. And that’s why you’ll continue to be hopeless.
Raging against “Excel spreadsheets” just shows how desperate you are to keep your mind closed.
• Ash signed Winfield. Totally his idea.
• The 91 squad was better than the 93 squad? What the hell is Gillick talking about? Go look at the starting lineup for ’93 WS Game 6 — Cito has Alomar batting 6th!!! Can you imagine a team where your 6th batter is HOFer Roberto Fucking Alomar?
• Actually, Andrew, I do. because it was extensively reported at the time. You were about 6 then, weren’t you? I wasn’t. I remember the commentators at the time–who would be Dan Shulman and Buck Martinez–talking about how the veterans on the team had really made a difference to the way the rookies prepared themselves. I wasn’t in the clubhouse but they were. This bunch of veterans don’t seem to be making the same impact on this bunch of rookies. You can yell and talk about ‘mouth-breathers’ all you want. But I will suggest that those of us who have been around long enough to be adults when the team was winning remember fondly that clubhouse and miss it. It is not ‘dumb’ or ‘stupid’ to assert that there is more to winning than just fielding a bunch of talented guys. Because this last version of the team was a bunch of really talented guys were they not? But they didn’t win. They started out bad and went into a tailspin from which they never recovered. Maybe a clubhouse leader or three could have pulled them out of that.
• Those people have absolutely zero idea, and what they were imparting to you was pure mythology. Sorry.
Martinez and Shulman were in the clubhouse minimally. Stop believing this nonsense.
What could have pulled the Jays out of their tailspin was a healthy Brandon Morrow and Josh Johnson, and Dickey and Buehrle figuring it out sooner. Don’t be so blindly naive.
• I’m sorry I must have missed something. Were you in the clubhouse then? Why do we take your narrative at face value and theirs as ‘mythology’? Because it doesn’t seem to me like you spend any time in the clubhouse either so both you and they are dependent on other people’s narratives.
In any case, let’s look at what happened when they went on their 11-game win-streak.
Chien-Ming Wang pitched two excellent games. Mark Buehrle recovered his previous form and began to pitch reasonably well. Esmil Rogers pitched well. Josh Johnson pitched well. The hitters hit, the bullpen performed admirably. It was lovely! Then they went to Tampa Bay. (I was staying at the same hotel! Saw them arrive! What a thrill!!) Except they hit the skids. And stayed skidding. that is where they needed to be pulled back from the brink and by then Buehrle was pitching well, Esmil Rogers had stepped up. The bullpen was in great shape. But skid they did and they stayed skidding.
Honestly I don’t think leadership is The Answer. But I do think it’s a part of a team doing well. Maybe leadership is only a factor when it’s missing. Like managers. A reasonably good manager won’t make that much of an impact on wins and losses. A bad manager may well.
• Sorry, too many ‘skids’ there. An edit button please!!
• It’s guys like Buck Martinez and Pat Tabler (who are in the dressing room and all that) who suggested Kawasaki making everyone loose and relaxed was a huge part of the winning streak, too.
Jack Morris always talks about guys needing the “will to win” and how he would “pitch to the score”.
Just because someone on TV believes it doesn’t make it true.
• “pitching to the score” is an obvious concept. When you’re ahead, the pitcher throws more fastballs and aims for a bigger part of the plate. For several reasons. 1) You get more quick outs (hopefully), 2) You save the bullpen, 3) You minimize walks, 4) you make them hit you to get back in the game.
I dunno if I agree with it (to a certain extent I do), but I don’t see why people view it as such a strange concept.
• Because it has been clearly and unequivocally disproven.
Makes sense if you don’t want to actually think about it or look at the data, though, I guess.
• Stoten…you sound like a moron. How hard is it to understand? These players are human beings and character and leadership DOES play a part. understand, dink?
25. Was Lind there? He’s been a little weird lately with his talk of AA needing to see him face to face “like a man”.
• In fact, as much as I like Lind, he’s the only one dumb enough to stir that pot.
• Didn’t Janssen make some comments close to this line a couple of times during the season?
26. The biggest grinder on the team was Kawasaki, not Lawrie. Albeit not in the hockey sense.
27. I mean, I applaud Stoeten’s optimism and patience, I really do. But sometimes I wish for more of the “fan” Stoeten that was quick to call out bullshit and diagnose problems (as recently as last year).
So Bautista is an exemplary leader, we have no leadership / clubhouse issues, our team DNA is perfect, our training staff is great and has nothing to do with us losing the most man-games to injury for the past two years in a row, things will come around, just bad luck.
Soooo… there is no problem? Just catcher and 2B? I mean, I understand that uselessness in just being negative, but there is a fine line between that and realistic. I really can’t understand how you do it. Every piece is like an explanation for something. Does not all of this add up to the fact that we are just a very poor baseball team, comprised of the wrong players who may be “talented” but aren’t real big time performers? Because it sure as hell looks like it.
• You understand this is a sport right? A sport played against OTHER teams. A sport where injuries DO happen and where they happen randomly. Not random like in your MLB The Show video game – but really truly randomly. You understand that leadership is an undefined, let alone measured, quality. It is not a number next below “Hit points” in an RPG.
And you know that this same exact Jays team with the same exact injury troubles STILL would have probably had a chance at winning 3 or 4 of the other division titles? (Look at our inter vs inra divisional record, and then look at the record of other teams against the AL East.)
Stoeten is a big annoying complainer. And he answers half my comments with only the word “nonsense”. But the day he complains enough to satisfy puck heads like you is the day I leave.
• This is pathetic. That is the worst excuse ever.
“Hey, we’re a really, really good team…but unfortunately we never win because other teams are even better!! If only they stopped trying, we’d be amazing!!”
• So invent some complete bullshit to explain it then, right?
• It’s not an excuse. Excuse are what I use to save my own bacon. It’s just simple math dude. Sorry you don’t understand.
• Most of your points are nonsense. Did you ever hear anyone from the Jays say that the whole problem is that the other teams are just too gosh darn good? Hell, did you happen to have noticed the cabal of shitballers that were trotted out to start because 3/5 of the rotation was injured?
• Wilner says it doesn’t matter…..lossesdon’t count
• Talent wins baseball games, not these stupid ghosts you pretend exert massive influence.
The issue with the club in 2013 was entirely about talent and health, not anything else.
• Damn straight. You can’t convince me that the teams in the playoffs are there because they have a couple players that are true leaders. It’s talent, it’s staying healthy. I think the only real untangible that might help out as well is baseball IQ – knowing what to do when. I see the same thing on my softball team – when a player is missing from a game that isn’t good at knowing where to be or what to do on certian plays, it helps a lot.
But, I digress. Can we honestly look up and down the rosters of teams like the Braves, Dodgers, A’s, etc and say “wow, good thing they had this veteran on the team whose clubhouse presence I know nothing about; otherwise they’d have sucked!”? No. But, we CAN look at the rosters and say, “hey look, they weren’t completely fucked by injuries!” and “hey, that team is pretty good!” It’s baseball – it’s a fluid sport played over 6 months that requires a lot to break right – you can assemble a great team with great players and avoid injuries and STILL not win enough games to make it. Talk to teams like San Francisco and Washington and Baltimore about that.
Leadership is part of a narrative that exists when you’re talking about a team that ultimately wins. No one at all is talking about, on the eve of the AL and NL DSs, that Team X is going to win a 5-game baseball series because they have Players A, B and C with great leadership abilities. They’re talking about those teams being favoured to win because they have players A, B and C that are difference-makers in terms of TALENT. They’re talking about teams having less chance to win a series because a key TALENTED player is hurt (Matt Kemp, for example).
Stoeten, I feel your pain on this, I truly do.
• Man you gotta broaden your mind a little. Sports are not that simple.
28. Since people have been grasping at straws to explain why the season went south so here is my contribution. 2013 is a number with many characteristics….
It is an odd number.
It is composite and its prime factorization are 3 \times 11 \times 61.
Its binary representation is 111110011101.
It is an odious number.
It repeats a single digit is base 13 (bbb_{13}).
It divides 34^5 – 1.
Its Roman Numeral is MMXIII.
These characteristics of the number 2013 signify that the Jays were going to lose this season.
29. Interesting fact from Verducci at CNNSI – Jays had 15 more wins against teams with winning records than Indians.
• I found it interesting when I learned that the Rays had a losing record away from the Trop until winning in Arlington in the 163rd game.
30. Footnotes in the post. I love it!
31. Something happen please tired of this Chemistry talk
32. So let’s go through a process of elimination for who could have made that comment. Let’s assume this person is not a hypocrite and eliminate everyone who was injured at some point for any significant length of time. Continuing that logic, let’s assume it was not a bench player or someone from the minors who spent half the season or more not playing. Who does that leave us? Fortunately/unfortunately, not many people.
Pitchers: Buehrle, Dickey, Rogers, Janssen
Position Players: Arencibia, Lind
Next, let’s assume a pitcher is not ignorant enough to throw several every day position players under the bus when he only pitches every 5th day, or in Janssen’s case, a couple of innings a week.
That leaves Arencibia and Lind. I know people dislike JP and he’s brought a lot of that on himself with his behaviour, but do we really want to believe that he is so hopelessly dumb that he would risk making a comment like that to a member of the media after his disaster of a season? I’m willing to give him more credit than that.
So that leaves Lind. He had a good enough year to have some swagger about his own performance and has never come across as the sharpest tool in the shed. He’s also made some questionable satements to the media before. So Adam is our man. Solved.
• I’m still thinking it was Oliver. My guess is that his feelings were hurt that enough guys didn’t stick around to see him off after ending a 20-year career.
As folksy as Lind might seem at times, I don’t think someone returning would throw his teammates under the bus. The comments reek of someone knowing they won’t be back.
• Oliver makes sense. He’s got nothing to lose. It’s like Omar Vizquel last year. He said what he had to say then got out of Dodge. What’s tiresome is that it’s 2 years straight of snarky so moments from veterans at the end of the season. Tiresome for many reasons.
• Lind? Hasn’t he had a couple of injury-plagued years? I suppose it could be him. Especially if someone had forgotten to give him his catnip.
• It would not surprise me at all if it was Dickey or Buehrle
33. I started reading the Sun story about Don Cherry, but I stopped after 3 words.
Any story that starts with the words, “Don Cherry thinks…” .
I prefer my fiction less fantasical.
34. All that leadership talk gives me a headache. I just came here to say, I’m happy to see the reference to Ball Four, which everyone should read. The end.
35. Stoets, I can’t wait to see your post about Griffin’s article today. wow it should be a doozy.
• It’s gonna happen. Would have this afternoon if not for the bar across the street.
• Drinking in a bar when a column beckons to be written? I’m going to a website where the proprietor is a grinder and displays better leadership qualities.
36. What the fuck happened to the saying, “Leave it all on the field”. It’s not just a reference to effort. Professional athletes don’t throw their teammates under the bus, especially when the one being thrown under is a player who has the ability to carry this team at different points in the year. Does Jose argue with umpires because he doesn’t care about the game. If a player is ‘distracted ‘ by Jose’s antics, then maybe they’re the one who isn’t focused on their own performance. *cough*JP sucks*cough*
I don’t know what’s worse, players who think they know what the G.M. needs to do, or the local media trying to give them a huge platform for their “very un-team-like comments”. The Toronto media has a knack for blowing shit out of proportion, so this really doesn’t surprise me that they are trying to lay blame for what went wrong this season, when it’s pretty fucking obvious. Too many key player injured to field a competitive team. That’s why their journalist, and not scientist. Because science actually consists of real, accurate information, not some bullshit conjured up to sell newspapers.
37. Lmfao that pic is hilarious. Jose is gonna kill him for that one. Payback is coming
38. I think the anonymously quoted player is that prick, Kawasaki.
39. [...] I guess it had to happen at some point after the type of season the Jays had. Over at Drunk Jays Fans Andrew Stoeten did a piece earlier in the week referencing Bob Elliot’s piece in the Toronto [...]
40. FYI: Dan Schulman was not the play-by-play guy in 1991. It was Jim Hughson.
http://en.wikipedia.org/wiki/1991_Toronto_Blue_Jays_season
41. Agree with you, Andrew. I think he bottomline is that this was an extremely disappointing season. A lot of things went wrong and maybe leadership or he lack of some players being willing to push through some pain has something to do with it. Or maybe not. All we know for sure is that the manager (or was it GM?) intimated as such during the year. R.A. Dickey came right out and said it (and if I had to barter a guess he source in he article might be him).
As for Bautista, who knows. I would guess it would be a distraction but that’s a completely uneducated guess.
At the end of the day, winning fixes everything and regardless of which way guys were pulling on the rope, fixing he “grit” wouldn’t have made the Jays a playoff team in 2013.
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https://peekingduck.readthedocs.io/en/stable/use_cases/privacy_protection_license_plates.html | ## Overview
Posting images or videos of our vehicles online might lead to others misusing our license plate numbers to reveal our personal information. Our solution performs license plate anonymization, and can also be used to comply with the General Data Protection Regulation (GDPR) or other data privacy laws.
Our solution automatically detects and blurs vehicles’ license plates. This is explained in the How It Works section.
## Demo
To try our solution on your own computer, install and run PeekingDuck with the configuration file privacy_protection_license_plates.yml as shown:
Terminal Session
[~user] > peekingduck run --config_path <path/to/privacy_protection_license_plates.yml>
## How It Works
There are two main components to license plate anonymization:
We use open-source object detection models under the YOLOv4 family to identify the locations of the license plates in an image/video feed. Specifically, we offer the YOLOv4-tiny model, which is faster, and the YOLOv4 model, which provides higher accuracy. The locations of detected license plates are returned as an array of coordinates in the form $$[x_1, y_1, x_2, y_2]$$, where $$(x_1, y_1)$$ is the top left corner of the bounding box, and $$(x_2, y_2)$$ is the bottom right. These are used to form the bounding box of each license plate detected. For more information on how to adjust the license plate detector node, check out the license plate detector configurable parameters.
To perform license plate de-identification, the areas bounded by the bounding boxes are blurred using a Gaussian blur function.
## Nodes Used
These are the nodes used in the earlier demo (also in privacy_protection_license_plates.yml):
nodes:
- input.visual:
source: <path/to/video with cars>
- draw.blur_bbox
- output.screen
By default, model.yolo_license_plate uses the v4 model type to detect license plates. If faster inference speed is required, the v4tiny model type can be used instead.
You can choose to mosaic or blur the detected license plate using the draw.mosaic_bbox or draw.blur_bbox node in the run config declaration.
• score_threshold: The bounding boxes with confidence score less than the specified score threshold are discarded. (default = 0.1)
• iou_threshold: The overlapping bounding boxes above the specified Intersection over Union (IoU) threshold are discarded. (default = 0.3)
In addition, some common node behaviors that you might want to adjust for the dabble.mosaic_bbox and dabble.blur_bbox nodes are:
• mosaic_level: Defines the resolution of a mosaic filter ($$width \times height$$); the value corresponds to the number of rows and columns used to create a mosaic. (default = 7) For example, the default value creates a $$7 \times 7$$ mosaic filter. Increasing the number increases the intensity of pixelization over an area.
• blur_level: Defines the standard deviation of the Gaussian kernel used in the Gaussian filter. (default = 50) The higher the blur level, the greater the blur intensity. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2708854675292969, "perplexity": 2242.3134732090325}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711286.17/warc/CC-MAIN-20221208082315-20221208112315-00788.warc.gz"} |
http://skranz.github.io/RTutor/reference/get.ps.html | Either a globally stored problem set or if RTutor runs as a web-app the associated problem set with the current shiny session
get.ps(force.global = FALSE) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6698244214057922, "perplexity": 6291.5255358377735}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572021.17/warc/CC-MAIN-20220814083156-20220814113156-00151.warc.gz"} |
http://www.ams.org/mathscinet-getitem?mr=311657 | MathSciNet bibliographic data MR311657 (47 #219) 13G05 Jensen, C. U. On ${\rm Ext}\sp{1}\sb{R}(A,\,R)$${\rm Ext}\sp{1}\sb{R}(A,\,R)$ for torsion-free $A$$A$. Bull. Amer. Math. Soc. 78 (1972), 831–834. Article
For users without a MathSciNet license , Relay Station allows linking from MR numbers in online mathematical literature directly to electronic journals and original articles. Subscribers receive the added value of full MathSciNet reviews. | {"extraction_info": {"found_math": true, "script_math_tex": 2, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9971023797988892, "perplexity": 7868.789578180943}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-48/segments/1386163052727/warc/CC-MAIN-20131204131732-00084-ip-10-33-133-15.ec2.internal.warc.gz"} |
http://calculator.mathcaptain.com/pyramid-calculator.html | A Pyramid is a 3D geometrical figure with a polygonal base where each side of base is joined with triangular faces having a common vertex on the other end.
Here are given two pyramids:
A triangular pyramid is a type of pyramid having a three sided triangular faces whose vertices are joined to a triangular base. It has 4 vertices and 1 base.
A square pyramid is a pyramid four triangular sides joined to a square base. It has 5 vertices and 1 base.
Pyramid Calculator has two calculators. Square Pyramid Calculator is a online tool used to find the area of square base, surface area and volume of square pyramid.Triangular Pyramid Calculator is a online tool used to find the area of triangular base, surface area and volume of triangular prism.
Pyramid Formula
Step 1 : Read the given problem and observe the quantities given. If side length (s), slant height (l), height (h) are given find the square pyramid parameters. If the Apothem length (a), side length (s), slant height (l) and height (h) are given, find the triangular pyramid parameters.
Step 2 :
Square pyramid parameters can be calculated using the below formulas
• Area of square base = s2
• Surface Area of square pyramid = s2 + 2sl
• Volume of square pyramid = $\frac{1}{3}$ $\times$ b2 $\times$ h
Where s = side length,
l = slant height,
h = height
b = base height
Triangular pyramid parameters can be calculated using the below formulas
• Area of triangular base = $\frac{1}{2}$ $\times$ a $\times$ s
• Surface Area of triangular pyramid = $\frac{1}{2}$ $\times$ a $\times$ s + $\frac{3}{2}$ sl
• Volume of triangular pyramid = $\frac{1}{6}$ $\times$ a $\times$ b $\times$ h
Where a = Apothem length,
s = side length,
l = slant height,
b = base height,
h = height.
Put the values in above formula and get the answer.
Prism Calculator
The Pyramids Volume of Pyramid What is a Rectangular Pyramid What is a Triangular Pyramid Cross Section of a Pyramid Formula for Volume of a Rectangular Pyramid
Pyramid Volume Calculator Calculate Compound Interest Calculator Calculate Simple Interest Calculator Calculate Standard Deviation Calculator A Division Calculator A Fraction Calculator | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7685441970825195, "perplexity": 1216.5769795318665}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1414119653672.23/warc/CC-MAIN-20141024030053-00021-ip-10-16-133-185.ec2.internal.warc.gz"} |
http://en.wikipedia.org/wiki/Close-packing_of_equal_spheres | # Close-packing of equal spheres
Regular arrangement of equal spheres in a plane changing to an irregular arrangement of unequal spheres (bubbles).
hcp and fcc close-packing of spheres
In geometry, close-packing of equal spheres is a dense arrangement of congruent spheres in an infinite, regular arrangement (or lattice). Carl Friedrich Gauss proved that the highest average density – that is, the greatest fraction of space occupied by spheres – that can be achieved by a lattice packing is
$\frac{\pi}{3\sqrt 2} \simeq 0.74048.$
The same packing density can also be achieved by alternate stackings of the same close-packed planes of spheres, including structures that are aperiodic in the stacking direction. The Kepler conjecture states that this is the highest density that can be achieved by any arrangement of spheres, either regular or irregular. This conjecture is now widely considered proven by T. C. Hales.[1][2]
Many crystal structures are based on a close-packing of a single kind of atom, or a close-packing of large ions with smaller ions filling the spaces between them. The cubic and hexagonal arrangements are very close to one another in energy, and it may be difficult to predict which form will be preferred from first principles.
## fcc and hcp lattices
There are two simple regular lattices that achieve this highest average density. They are called face-centered cubic (fcc) (also called cubic close packed) and hexagonal close-packed (hcp), based on their symmetry. Both are based upon sheets of spheres arranged at the vertices of a triangular tiling; they differ in how the sheets are stacked upon one another. The fcc lattice is also known to mathematicians as that generated by the A3 root system.[3]
### Cannonball problem
Cannonballs piled on a triangular (front) and rectangular (back) base, both fcc lattices.
The problem of close-packing of spheres was first mathematically analyzed by Thomas Harriot around 1587, after a question on piling cannonballs on ships was posed to him by Sir Walter Raleigh on their expedition to America.[4] Cannonballs were usually piled in a rectangular or triangular wooden frame, forming a three-sided or four-sided pyramid. Both arrangements produce a face-centered cubic lattice – with different orientation to the ground.
### Positioning and spacing
In both the fcc and hcp arrangements each sphere has twelve neighbors. For every sphere there is one gap surrounded by six spheres (octahedral) and two smaller gaps surrounded by four spheres (tetrahedral). The distances to the centers of these gaps from the centers of the surrounding spheres is $\scriptstyle \sqrt{\frac{3}{2}}$ for the tetrahedral, and $\scriptstyle \sqrt2$ for the octahedral, when the sphere radius is 1.
Relative to a reference layer with positioning A, two more positionings B and C are possible. Every sequence of A, B, and C without immediate repetition of the same one is possible and gives an equally dense packing for spheres of a given radius.
The most regular ones are:
• fcc = ABCABCA (every third layer is the same)
• hcp = ABABABA (every other layer is the same).
In close-packing, the center-to-center spacing of spheres in the xy plane is a simple honeycomb-like tessellation with a pitch (distance between sphere centers) of one sphere diameter. The distance between sphere centers, projected on the z (vertical) axis, is:
$\text{pitch}_Z = \sqrt{6} \cdot {d\over 3}\approx0.81649658 d,$
where d is the diameter of a sphere; this follows from the tetrahedral arrangement of close-packed spheres.
The coordination number of hcp and fcc is 12 and its atomic packing factor (APF) is the number mentioned above, 0.74.
Comparison between hcp and fcc
Figure 1 – The hcp lattice (left) and the fcc lattice (right). The outline of each respective Bravais lattice is shown in red. The letters indicate which layers are the same. There are two "A" layers in the hcp matrix, where all the spheres are in the same position. All three layers in the fcc stack are different. Note the fcc stacking may be converted to the hcp stacking by translation of the upper-most sphere, as shown by the dashed outline.
Figure 2 – Shown here is a stack of eleven spheres of the hcp lattice illustrated in Figure 1. The hcp stack differs from the top 3 tiers of the fcc stack shown in Figure 3 only in the lowest tier; it can be modified to fcc by an appropriate rotation or translation. Figure 3 – Thomas Harriot, circa 1585, first pondered the mathematics of the cannonball arrangement or cannonball stack, which has an fcc lattice. Note how adjacent balls along each edge of the regular tetrahedron enclosing the stack are all in direct contact with one another. This does not occur in an hcp lattice, as shown in Figure 2.
## Lattice generation
When forming any sphere-packing lattice, the first fact to notice is that whenever two spheres touch a straight line may be drawn from the center of one sphere to the center of the other intersecting the point of contact. The distance between the centers along the shortest path namely that straight line will therefore be r1 + r2 where r1 is the radius of the first sphere and r2 is the radius of the second. In close packing all of the spheres share a common radius, r. Therefore two centers would simply have a distance 2r.
### Simple hcp lattice
An animation of close-packing lattice generation. Note: If a third layer (not shown) is directly over the first layer then the HCP lattice is built, if the third layer is placed over holes in the first layer then the FCC lattice is created
To form an A-B-A-B-... hexagonal close packing of spheres, the coordinate points of the lattice will be the spheres' centers. Suppose, the goal is to fill a box with spheres according to hcp. The box would be placed on the x-y-z coordinate space.
First form a row of spheres. The centers will all lie on a straight line. Their x-coordinate will vary by 2r since the distance between each center if the spheres are touching is 2r. The y-coordinate and z-coordinate will be the same. For simplicity, say that the balls are the first row and that their y- and z-coordinates are simply r, so that their surfaces rest on the zero-planes. Coordinates of the centers of the first row will look like (2rrr), (4rrr), (6r ,rr), (8r ,rr), ... .
Now, form the next row of spheres. Again, the centers will all lie on a straight line with x-coordinate differences of 2r, but there will be a shift of distance r in the x-direction so that the center of every sphere in this row aligns with the x-coordinate of where two spheres touch in the first row. This allows the spheres of the new row to slide in closer to the first row until all spheres in the new row are touching two spheres of the first row. Since the new spheres touch two spheres, their centers form an equilateral triangle with those two neighbors' centers. The side lengths are all 2r, so the height or y-coordinate difference between the rows is $\scriptstyle\sqrt{3}r$. Thus, this row will have coordinates like this:
$\left(r, r + \sqrt{3}r, r\right),\ \left(3r, r + \sqrt{3}r, r\right),\ \left(5r, r + \sqrt{3}r, r\right),\ \left(7r, r + \sqrt{3}r, r\right), \dots.$
The first sphere of this row only touches one sphere in the original row, but its location follows suit with the rest of the row.
The next row follows this pattern of shifting the x-coordinate by r and the y-coordinate by $\scriptstyle\sqrt{3}$. Add rows until reaching the x and y maximum borders of the box.
In an A-B-A-B-... stacking pattern, the odd numbered planes of spheres will have exactly the same coordinates save for a pitch difference in the z-coordinates and the even numbered planes of spheres will share the same x- and y-coordinates. Both types of planes are formed using the pattern mentioned above, but the starting place for the first row's first sphere will be different.
Using the plane described precisely above as plane #1, the A plane, place a sphere on top of this plane so that it lies touching three spheres in the A-plane. The three spheres are all already touching each other, forming an equilateral triangle, and since they all touch the new sphere, the four centers form a regular tetrahedron.[5] All of the sides are equal to 2r because all of the sides are formed by two spheres touching. The height of which or the z-coordinate difference between the two "planes" is $\scriptstyle\sqrt{6}r2/3$. This, combined with the offsets in the x and y-coordinates gives the centers of the first row in the B plane:
$\left(r, r + \frac{\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(3r, r + \frac{\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(5r, r + \frac{\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(7r, r + \frac{\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right), \dots.$
The second row's coordinates follow the pattern first described above and are:
$\left(2r, r + \frac{4\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(4r, r + \frac{4\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(6r, r + \frac{4\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\ \left(8r,r + \frac{4\sqrt{3}r}{3}, r + \frac{\sqrt{6}r2}{3}\right),\dots.$
The difference to the next plane, the A plane, is again $\scriptstyle \sqrt{6}r2/3$ in the z-direction and a shift in the x and y to match those x- and y-coordinates of the first A plane.[6]
In general, the coordinates of sphere centers can be written as:
$\begin{bmatrix} 2i + ((j\ +\ k)\ \bmod{2})\\ \sqrt{3}\left[j + \frac{1}{3}(k\ \bmod{2})\right]\\ \frac{2\sqrt{6}}{3}k\\ \end{bmatrix}r$
where $i$, $j$ and $k$ are indices starting at $0$ for the $x$, $y$ and $z$ coordinates.
## Miller indices
Main article: Miller index
Miller–Bravais index for hcp lattice
Crystallographic features of hcp systems, such as vectors and atomic plane families can be described using a four-value Miller index notation ( hkil ) in which the third index i denotes a convenient but degenerate component which is equal to −h − k. The h, i and k index directions are separated by 120°, and are thus not orthogonal; the l component is mutually perpendicular to the h, i and k index directions.
## Filling the remaining space
The FCC and HCP packings are the densest known packings of equal spheres. Denser sphere packings are known, but they involve unequal sphere packing. A packing density of 1, filling space completely, requires non-spherical shapes, such as honeycombs.
Replacing each contact point between two spheres with an edge connecting the centers of the touching spheres produces tetrahedrons and octahedrons of equal edge lengths. The FCC arrangement produces the tetrahedral-octahedral honeycomb. The HCP arrangement produces the gyrated tetrahedral-octahedral honeycomb. If, instead, every sphere is augmented with the points in space that are closer to it than to any other sphere, the duals of these honeycombs are produced: the rhombic dodecahedral honeycomb for FCC, and the trapezo-rhombic dodecahedral honeycomb for HCP.
Spherical bubbles in soapy water in a FCC or HCP arrangement, when the water in the gaps between the bubbles drains out, also approach the rhombic dodecahedral honeycomb or trapezo-rhombic dodecahedral honeycomb. However, such FCC of HCP foams of very small liquid content are unstable, as they do not satisfy Plateau's laws. The Kelvin foam an the Weaire Phelan foam are more stable, having smaller interfacial energy in the limit of a very small liquid content. [7] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 19, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.844042956829071, "perplexity": 752.1928931778668}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1430452189638.13/warc/CC-MAIN-20150501034949-00063-ip-10-235-10-82.ec2.internal.warc.gz"} |
https://edurev.in/studytube/Dynamical-systems-4/716d8441-8219-4da6-ad76-b17a91b97a24_t | Dynamical systems - 4
# Dynamical systems - 4 Notes | Study Physics for IIT JAM, UGC - NET, CSIR NET - Physics
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Centres and foci
Next special case we consider is the dynamical system of the form
Fig. 8.9. Phase portrait for dynamical system (8.20). Blue line represents unstable manifold, red line represents stable manifold.
(8.21)
Matrix of this system is
(8.22)
System (8.21) is little trickier to solve. Let us switch to polar coordinate system by usual transformation
x = r cos θ; y = r sin θ;
where r = r(t) and θ = θ(t). Inverse transformation reads
These relations can be used to find
Now we use (8.21) to derive corresponding equations for r and θ:
We can see that dynamical system (8.21) in polar coordinates decouples to two independent equations for coordinates r and θ,
(8.23)
First we solve equation for r. Let us write it in the form
which integrates to
log r = α t + log C
where the integration constant has been written as a logarithm (see footnote on page 162). Exponentiating the last equation we arrive at
Obviously, at time t = 0 we have r(0) = C and so we write the solution in the form
Next we solve equation for θ. This is trivial since we have
which integrates to
where the integration constant has been denoted by θ0 and represents the value of θ at t = 0. Summa summarum, solution of system (8.23) acquires the form
(8.24)
Hence, solution of original system (8.21) in the Cartesian coordinates reads
(8.25)
Suppose that α = 0 so that
Clearly, this represents motion at constant angular velocity β and constant radius r0 and therefore the phase trajectories are circles of radius r0. If
α ≠ 0, the radius of the "circle" will be
and hence the trajectory will be a spiral. If α > 0, the radius will increase exponentially and the spiral will tend to in nity. If, on the other hand, α < 0, the radius will decrease exponentially and the phase tra jectories will spiral towards the origin. All cases are plotted in gure 8.10 by Mathematica commands
and can be classi ed as follows:
• α = 0 Critical point is called centre. Tra jectories are circles centred at the origin.
• α > 0 Critical point is called unstable focus, tra jectories are spirals escaping to in nity.
• α < 0 Critical point is called stable focus, tra jectories are spirals tending to the origin.
Parameter β has the meaning of angular velocity. If it is zero, spirals become straight lines and dynamical system reduces to previous case (8.17). If it is non-zero, its sign determines the sense of rotation: tra jectories orbit the origin in a clockwise sense for β > 0 and in a counter-clockwise sense for β < 0.
Let us now analyse critical points of system (8.21) in terms of eigenvalues of matrix (8.22)
We can use Mathematica to nd the eigenvalues and eigenvectors of matrix (8.22) by
which shows that this matrix has two eigenvalues
with eigenvectors
In other words, eigenvalues and eigenvectors of matrix J satisfy relations
The rst observation is that the eigenvectors are complex and hence there are no neither stable nor unstable manifolds, i.e. there is no real direction which is mapped to the same direction. The only exception is when β = 0 since in this case dynamical system (8.21) reduces to (8.17) and the eigenvectors become real.
Second, eigenvalues λ1,2 are mutually complex conjugated (as well as the eigenvectors),
Fig. 8.10. Classi cation of critical points for the system (8.21): a, b) centre, c) unstable focus, d) stable focus.
where the bar denotes the complex conjugation. Hence, even if the dynamical system is not of the form (8.21), we can conclude, that if the matrix J has two complex conjugated eigenvalues
the critical point is stable/unstable focus or a centre, depending on the values of α and β as classi ed above.
Example. Consider dynamical system
This system is not of the form (8.21) but we can apply the criterion based on the analysis of eigenvalues. In Mathematica we type
where we have used Expand in order to simplify the expression for eigenvectors (try this code without Expand). We have found two eigenvalues
which are mutually complex conjugated. In this case, parameters α and β are
Parameter α is positive and so the critical point is an unstable focus. Tra jectories of dynamical system considered:
Another example is the system
Eigenvalues are found by
Hence, now the eigenvalues are
which means that
Since α = 0, critical point is a centre rather than focus. Tra jectories of this dynamical system are the following:
General case
In the previous two sections we studied two special cases of planar linear dynamical systems given by matrices
However, we have seen that the analysis can be performed using the eigenvalues of these matrices. Now we consider general linear planar dynamical system
(8.26)
Let us find the eigenvalues and eigenvectors of this general matrix. Recall that the determinant of matrix J is
The trace of the matrix is de ned as a sum of its diagonal elements, i.e.
Eigenvalues λ are defined by equation
where e is an eigenvector. The last equation can be rewritten in the form
where I is the unit matrix 2 x 2 so that
This equation is a homogeneous system of linear equations which has non-trivial solutions only if the determinant of the system is zero:
Expanding the brackets we arrive at
or, equivalently
This is a quadratic equation for λ and its solutions are
(8.27)
Now we can summarize the classification of critical points as follows.
Moreover, if the real parts of eigenvalues λ1,2 are non-zero, critical point is called hyperbolic, otherwise it is called non-hyperbolic.
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https://planet.dante.de/ | # TeX & Friends (Planet by DANTE e.V.)
## 2021-09-29
### TUG
#### TUGboat 42:2 published
TUGboat volume 42, number 2, the TUG 2021 conference proceedings, has been mailed to TUG members. It is also available online and from the TUG store. In addition, prior TUGboat issue 42:1 is now publicly available. Submissions for the next issue are welcome; the deadline for proposals is October 15 (early submissions are especially appreciated). Please consider joining or renewing your TUG membership if you haven't already (we'll send this year's issues immediately), and thanks.
# The second LaTeX pre-release for 2021-11-15 is available for testing
A few days ago we submitted a new LaTeX development format to CTAN and by now it should be available to all users using MiKTeX or TeX Live (on any operating system).
## Main features of the second pre-release for 2021-11-15
The first pre-release was just a copy of the main release for 2021-06-01 in order to avoid that people using the development release regularly get an old format.
The second pre-release now provides some improvements of the hook management as a result of feedback from developers and our own experience applying the new functionality. This includes one breaking change in behavior (relevant only to package developers), for which we offer compatibility code for now. Thus nothing will break right now, but going forward the new method needs to be used, because at some point in the future the compatibility code will be taken out.
Notable improvements already contained in the pre-release are
• Resolving some issues around the new hook functionality:
• Providing \ActivateGenericHook;
• Command to clear “next” hook code before invocation;
• Cleanup after a one-time hook;
• Changed the behavior of \RemoveFromHook;
• Standardizing generic hook names;
• Other improvements:
• \tracinglostchars got a new default
• \PackageNote was added to show notes that aren’t “warnings” on the terminal
• \ShowCommand got extended to show commands defined with ltcmd (former xparse)
• \NewCommandCopy got extended as well to safely these commands to new names
• alt key for \includegraphics (anticipating future development)
There are also a number of smaller enhancements and some bug fixes as usual. The more important ones are listed in the draft publication of LaTeX2e News Issue 34. A full list is given in the changes.txt files that are part of the distribution.
### Improving the hook management further
The breaking change mentioned above involves the name of generic file hooks. They used a special naming convention in the past and we now changed them to use the same structure as all other generic hooks, that is, their “variable” part (i.e., the file or package name) is always in the second position. For example, to execute some code after the array package was loaded you now say
\AddToHook{package/array/after}{...code...}
just like you would set up code to be executed after each tabular environment with
\AddToHook{env/tabular/after}{...code...}
For now the old syntax package/after/array is still supported, thus packages making use of this functionality have time to adapt to the new convention once the main release is out and distributed.
Other improvements to the hook management (e.g., the functionality to have packages implement generic hooks) are discussed in LaTeX2e News Issue 34 and in the relevant kernel documentation.
## Outlook
We expect to produce a third and final pre-release adding some more features and enhancements in late October.
We are issuing this second pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.
This development format allows you to test the upcoming LaTeX release scheduled for 2021-11-15 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.
Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release hits the streets.
Processing your documents with the pre-release is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
Enjoy — Frank
## 2021-09-06
### TUG
#### Computers&Typesetting: Jubilee printings
Pearson has published the 35th anniversary (Jubilee) printings of the complete C&T series, including all updates from the 2021 tune-up. They are available as both hardcover and pdf, with a 40% discount for TUG members. Details on the TUG books page. Happy reading!
## 2021-09-04
### LaTeX.net
#### DANTE Herbsttagung 2021
The following text is in German because it’s about the German language user group meeting 2021.
Im vergangenen Jahr sind leider beide DANTE-Tagungen wegen der Pandemie ausgefallen. Die Frühjahrstagung fand wegen der Kontaktbeschränkungen komplett online statt.
Auch die Herbsttagung wird virtuell stattfinden, über die Plattform „Online Schule Saarland“.
Das Programm, vom 17. bis 19. September 2021:
• Freitag, 17.9.: ab 19:30 Uhr Vorabendtreff
• Samstag,18.9.: ab 9 Uhr Begrüßung und Mitgliederversammlung , danach zwei Vorträge
• Color, xcolor und l3color: Farben in LaTeX (Ulrike Fischer)
• Futura PM – Eine geometrisch konstruierte Schriftart für (La)TeX (Philipp Müller)
• Sonntag, 19.9.: Stadtrundgang und Besuch historisches Museum
Siehe auch Programm und Tagungs-Seite.
An dieser Stelle auch ein Danke von mir an DANTE für die Unterstützung bei den Serverkosten dieser Webseite TeX-talk.net sowie der LaTeX-Foren TeXwelt.de, goLaTeX.de, LaTeX.org, TeXnique.fr, und weiteren Webseiten wie TeXfragen.de, LaTeX.net.br, TeXdoc.org, CTAN.net, TeXlive.net, TeX.my, TeXample.net, TikZ.net, pgfplots.net, TeXblog.net, mychemistry.eu, TeX.co, LaTeX.net und weiteren.
Photo by Amador Loureiro on Unsplash
## 2021-08-29
### LaTeX.net
#### The Island of TeX in 2020 and 2021
In 2020, the Island of TeX introduced Docker images for easily reproducible builds as well as a semi-official response to the need for continuous integration. These images were among the first using vanilla TeX Live, providing the required tools for running software included in TeX Live – for example, Java Virtual Machine, Python, and so forth. Additionally, the island provides TeX Live releases from 2014 on and let the user decide whether they want to pull all the documentation and source files into their CI configuration.
With attention came the idea to more officially publish our images as texlive/texlive, which the island gladly did. Now IoT manages the releases at Docker Hub as well: https://hub.docker.com/r/texlive/texlive.
Docker Hub is the world’s largest repository of container images with an array of content sources including container community developers, open source projects and independent software vendors building and distributing their code in containers.
Apart from applications in continuous integration, the Docker images have lured the island into creating another tool based on them. TeXdoc online is the successor to TeXdoc.net (which now redirects).
This tool provides a RESTful API for texdoc. A REST ful API is a stateless interface to web applications responding to typical HTTP requests with uniform responses. Usually, JSON is used for the response format. Following this principle, this software responds to HTTP GET requests with JSON representing documentation-related objects. There are several endpoints you can access.
The front end of TeXdoc online is structured in a similar way to TeXdoc.net. The main feature is still searching for packages. Topics are handled differently, though. We use CTAN’s JSON API to fetch their topics and packages belonging to these topics. Any user visiting the landing page will be shown six random categories with a few packages each. If a category holds several packages, four of them are selected at random. Users have the option to show all topics and list the packages for any topic they are interested in. Also, each package entry can be automatically queried for documentation.
Deploying the software is straightforward. You can get an executable JAR file with all dependencies included that you can simply run using your local Java installation. Running the JAR bundle will open a local web server that can be accessed from your browser. As an alternative to running the JAR file, the island also provides a dockerized image. This image is based on IoT’s TeX Live images, which makes it quite large in terms of file size but also eliminates the need for a local TeX installation. Using Docker is the preferred solution for hosting your own instance of TeXdoc online.
The Docker image also provides daily updates. The container will update daily at midnight (container time) and thus stays up to date as long as
the current version of TeX Live is supported. The island’s continuous integration ensures that you can always pull the latest tag and receive the latest and greatest TeX documentation, which when pulled and run will update itself.
To ease deployment, IoT provides a ready-made configuration for Docker Compose, an orchestration tool for Docker containers. It uses the Caddy web server to provide automatic HTTPS with local certificates or, on public domains, Let’s Encrypt certificates.
After finishing TeXdoc online to a production-ready degree, the island turned to the development of another handy tool, Albatross. This command line tool, with a silly yet adorable name, solves a very common problem: finding system fonts that provide a certain glyph. Users may provide the glyphs themselves or their corresponding Unicode code points in hexadecimal notation.
IoT also migrated checkcites, a tool for checking missing or unused references, from Paulo’s personal repository to the island. The team also decided to rewrite it from Lua to Kotlin — this is still a work in progress. And the island is going from a monolithic implementation to a modular one, which is also a work in progress.
In 2020, IoT finished version 5 of arara, a major rewrite from Java to Kotlin, mainly working on features from user feedback, especially directory support and the processing of multiple files. The team got hooked by the idea of aligning release schedules of arara with TeX Live releases enabling IoT to make (small) breaking changes more often. So the island had big plans and started to work on version 6 right after releasing version 5. As with checkcites, the team walked the extra mile and arara went from a monolithic implementation to a modular one, plus an enhanced feature set and optimized workflow.
In version 5, the implementation had everything contained in one big block. In version 6, IoT made a split between an API, a core implementation, the engine and the CLI application to separate concerns. This was the first step in the direction of splitting out components that are bound to one platform. Aditionally, the team hopes to enable other people to develop their own tools based on the arara libraries if they wish to. With multiple library components this should be easy. The developers of the TeXify IDEA plugin expressed their interest in this to integrate proper arara support in TeXify.
For version 7, the team wants to take larger steps towards platform-independence. Hence, IoT will make use of Kotlin/Multiplatform (MPP) to use a single codebase for all target platforms. Some components will have to be rewritten, some need different interfaces for different platforms but in the end, the team hopes to provide an even more multitalented tool.
Up to now, arara has been developed as a file-based build tool. The tool does not track dependencies nor does it manage projects. You throw a file at it and it makes the best out of it. The team is evaluating support for projects and dependencies. Other feature candidates include cleaner logs and granularity switchs, new DSL-based rules and configurations, and better integration with existing workflows.
The team has many plans and hopes to realize as much as possible. The island is a vibrant environment for the development of TeX-related tools; IoT wants to enhance the user experience, from newbie to expert, and promote use and diffusion of modern methodologies and technologies. If you are interested in helping the island develop ideas or even implementing some code, visas for the island are free and easy to get, so feel free to reach out.
## 2021-08-24
### Some TeX Developments (by Joseph Wright)
Usually, I keep my day job (as a university lecturer in chemistry) and my LaTeX work separate. Of course, I use LaTeX at work for things like lecture handouts, but most of the time the two areas don’t directly intersect.
So it was quite interesting to be talking yesterday at a chemistry conference (the ACS Fall 2021 Meeting) about siunitx. I’d been invited by Stuart Chalk to a session on units and data reuse: much more like metrology/computer science than my usual day-to-day wet chemistry!
It was good to see that many of the things I do in siunitx fit into wider efforts by people who do day-to-day work on units. The idea of logical mark-up for unit input, the ability to decompose units into parts and the realities of less-than-ideal input from users were all there. Hopefully, siunitx will help with the work being done by groups such as DRUM (Digital Representation of Units of Measure) to make information more computer-readable. I’ll also be looking at QUDT for inspiration about the real technical detail of the myriad of units in real use.
I also managed to get in a few comments about some LaTeX work that’s important for data reuse more widely: tagged PDFs and tex4ht. So it was a pretty productive use of an evening!
## 2021-07-06
### TUG
#### TUG 2021 presentation proposal deadline is July 9
The deadline for presentation proposals for TUG'21 is July 9. Please send in submissions as soon as possible. The conference will be held online, August 5-8. More info: call for papers, register (no charge), conference home page.
## 2021-07-04
### LaTeX.net
#### Scientific WorkPlace/Word/Notebook discontinued
MacKichan Software, Inc. stopped it’s business on June 30, 2021. Their products Scientific WorkPlace (SWP), Scientific Word, and Scientific Notebook, that are based on LaTeX, will not be sold or supported anymore.
The future plan for Scientific Word is to become Open Source after removing non-free/non-open components.
Image by Theodore Norvell
## 2021-06-03
### TikZ
StackExchange, bekannt als StackOverflow, ist an Prosus verkauft worden f체r 1,8 Milliarden Dollar. Das beinhaltet die TeX StackExchange Q&A Seite (TeX.SE). Prosus ist ein Technology-Investor und eine Holding Company die bereits Unternehmen wie Udemy, Codecadamy und Brainly (“Your 24/7 homework helper”) besitzt. Nach $153 Millionen Investor-Kapital, Einstellen eines fr체heren Investment-Bankers als Kopf, mehreren Entlassungs-Runden, Ausscheiden von Moderatoren, Effizienter-Werden duch Standardisieren der Sites, Aussteige-Spekulationen, war es nicht wirklich 체berraschend. Die offizielle Kommunikation und Joel Spolskys Bekanntmachung sagen “business as usual” und dass alles genauso weiterl채uft. Also, nix zu sehen hier. Es gibt auch nichtkommerzielle (La)TeX Q&A Seiten und Foren, unterst체tzt durch TeX user groups und vor allem DANTE, wie: LaTeX.org, TeXwelt.de, TeXnique.fr, and goLaTeX.de. ### LaTeX.net #### StackExchange has been sold The StackExchange network by Stack Overflow Inc., has been sold to Prosus for 1.8 billion dollars. That includes the TeX Stack Exchange Q&A site aka TeX.SE. Prosus is a technology investor and holding company that already owns some learning sites such as Udemy, Codecadamy, and Brainly (“Your 24/7 homework helper”). After$153 Million funding, hiring a former investment banker to lead the company, several round of layoffs, community moderators leaving, becoming more efficient by standardizing site designs, exiting rumours, it was not surprising. Official communication and Joel Spolskys announcement say “business as usual” and that it would operate in the same way. Like, nothing to see here.
There are also not-for-profit (La)TeX Q&A sites and forums, supported by TeX user groups and especially DANTE, such as: LaTeX.org, TeXwelt.de, TeXnique.fr, and goLaTeX.de.
# The Spring 2021 LaTeX release is available
This year Spring in LaTeX’s counting is somewhat delayed, but this fits the weather—at least here in Germany were we had April weather throughout most of May. We plan to keep it this way in future releases: a first release in May/June and a second release around November as this better fits with the release cycle of the TeXLive distribution.
The focus of this release is to provide further important building blocks for the future production of reliable tagged PDF output (see the article LaTeX Tagged PDF — A blueprint for a large project that describes the project we are engaged in); these enhancements are discussed below.
### Extending the hook concept to paragraphs
Largely triggered by the need for better control of paragraph text processing, in particular when producing tagged PDF output, we have changed LaTeX so that the kernel gains control both at the start and at the end of each paragraph. This is done in a manner that is (or should be) transparent to both packages and documents. We have also included four public hooks to enable adding code to paragraphs in a controlled manner. The documentation on this is available as ltpara-doc.pdf.
These hooks will enable us to automatically tag paragraphs and enables us to identify when paragraphs are broken across columns or pages, because those need special handling in tagged PDF.
### Extending the hook concept to commands
With this release we extended the set of “generic” hooks to commands: in theory each document-level command has now two hooks cmd/<command>/before and cmd/<command>/after in which packages (or the user in the preamble) can add code using the hook management machinery.
If you know the etoolbox package, then you can think of them as being similar to the use of \preto and \appto from that package, but with the difference that if different packages try to do that, the added code chunks can be controlled and ordered as needed using the hook mechanism. The documentation for this functionality can be found in ltcmdhook-doc.pdf.
In practice, not all commands can accept such generic hooks: some (especially those that take optional arguments) will break if you try using an /after hook with them. However, many will and that allows us in the future to easily patch the many commands to enable tagged PDF without touching or updating package code.
### A large number of other enhancements and corrections
There are many other enhancements and corrections that we documented in the ltnews article for this release (and a few very minor ones that only made it into the changes.txt file). The most important ones from a user perspective are:
• Further improvements of file name parsing; in particular we made the parsing much faster again (it got a little slow with the functional enhancements we introduced in the last releases)
• Better handling of font series and font shape changes
• Improved copy & paste from documents produced with pdfTeX
But read the whole ltnews article because there may be other gems that are useful for you.
The new features and most of the important bug fixes made in this release are documented in “LaTeX2e News Issue 33”. This document can be found on the LaTeX2e news page where you will also find release information for earlier LaTeX releases.
Happy LaTeXing — Frank
## 2021-05-24
### TikZ
#### Das coffeestains-Paket
Nach einem kurzen Gespr채ch auf TeXnique.fr hat Patrick Bideault das coffeestains-Paket auf TikZ portiert. Das urspr체nglich von Hanno Rein in 2009 entworfene Paket erfuhr damit eine Modernisierung und l채uft einwandfrei mit pdfLaTeX, XeLaTeX, und LuaLaTeX auf TeX Live 2021. Damit steht einer weiteren breiten Anwendung in den Homeoffices dieser Welt nichts im Wege.
Ein Anwendungsbeispiel mit viel Kaffee:
\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage{blindtext}
\usepackage{coffeestains}
\begin{document}
\coffeestainA{1}{1}{0}{6cm}{4cm}
\coffeestainB{0.8}{1}{-60}{-4cm}{4cm}
\coffeestainC{0.3}{1}{180}{0cm}{0cm}
\coffeestainD{0.5}{0.5}{100}{-1cm}{2cm}
\blinddocument
\end{document}
Die Syntax ist, verk체rzt: \coffeestain(A|B|C|D){Transparenz}{Skalierung}{Drehwinkel}{X-Offset}{Y-Offset}. Mehr steht in der Dokumentation, die auch mit viel Kaffee entstanden ist.
## 2021-05-22
### TikZ
#### Flaggen der Welt
Wilhelm Haager hat im April 2021 das Paket worldflags veröffentlicht. Damit kann man Flaggen aller Nationen und einiger weiterer Gebiete und Organisationen in TikZ zeichnen, sowohl als TikZ-Bild als auch als pic-Baustein. Durch eine Vielzahl Optionen kann man Breite, Höhe, “Hängen”, Spiegel, Drehen und mehr einstellen. Die einfachste Nutzung ist geht schon z.B. mit
\worldflag{BR}
was eine brasilianische Flagge zeichnet:
Mit etwas mehr Arbeit anhand des Beispiels im Handbuch mit Fahnenstangen:
\documentclass[border=10pt]{standalone}
\usepackage{worldflags}
\begin{document}
\begin{tikzpicture}[x=1mm,y=1mm]
\def\w{30}\def\d{20}
color(1mm)=(brown); color(2mm)=(black)}
\flagsdefault[width=15mm,hang=20]
\pic (fr) [country=FR,width=16mm,rotate=-\w] at (\d,0) {worldflag};
\pic (de) [country=DE,width=15mm,rotate=\w,turn=180] at (-\d,0) {worldflag};
rotate around={-\w:(fr-nw)}](fr-nw)-|++(-2,-60)-|cycle;
rotate around={\w:(de-nw)}](de-nw)-|++(2,-60)-|cycle;
\node [rotate={50},below left = 1.5cm and -0.6cm of de-nw] {\TeX welt.de};
\node [rotate={-50},below left = 1.2cm and 0.9cm of fr-ne] {\TeX nique.fr};
\end{tikzpicture}
\end{document}
Die Flaggen wurden mithilfe der Konstruktions-Angaben von vexilla-mundi.com gezeichnet, einige komplexere Embleme wurden aus SVG-Daten von Wikipedia mittels Inkscape in TikZ-Code übersetzt.
## 2021-05-20
### LaTeX.net
#### Wenn mal was in den Planeten rutscht
Wie hier notiert, ist es ja total einfach, LaTeX als kompletten und aktuellen Compiler in Blogs online zu verwenden.
Während ich gerade ein 10 Jahre altes Buch überarbeite damit es aktualisiert wird, verwende ich pro Kapitel eine Blog-Seite, um die sich im Kapitel entwickelnden Codes auf einer einzigen Seite zu haben und mit einem Klick zu übersetzen und zusammen zu überarbeiten bis es final ist. Ich hab halt sonst keinen Editor, der 12 Code-Beispiele auf einer Seite hat und jeden Teil mit einem Klick übersetzt, und das eben auch mit dem Smartphone unterwegs.
Lustigerweise rutscht es in Feed-Aggregatoren wie planet.dante.de obwohl es als Draft gespeichert ist und eigentlich nicht öffentlich sichtbar sein sollte.
Daher, sorry für den noise auf dem DANTE Planeten für zumindest einen reingerutschten Beitrag, wo auch noch User-Testcode von einem Forum-Beitrag drin war. Eigentlich mache ich das sonst auf einer separaten Buch-Webseite, die allen Code direkt on-page compilierbar enthält, analog LaTeX-Cookbook.net.
Sehen wir uns demnächst mit der Buch-Webseite und mehr Inhalten.
### TUG
#### TUGboat 42:1 published
TUGboat volume 42, number 1, a regular issue, has been mailed to TUG members. It is also available online and from the TUG store. In addition, prior TUGboat issue 41:3 is now publicly available. Submissions for the next issue, the TUG 2021 conference proceedings, are welcome; the deadline for proposals is June 24 (early submissions are especially appreciated). Please consider joining or renewing your TUG membership if you haven't already (you'll get this issue immediately), and thanks.
## 2021-05-17
### Some TeX Developments (by Joseph Wright)
#### Moving from siunitx v2 to v3
With v3 of siunitx out, I am as expected getting quite a few questions about moving from v2. In the main, this is quite easy as there is a decent amount of compatibility code. Here, I’ll pick out a few cases where you might want some adjustments.
## Working with Overleaf
One thing that people sometimes need is to work with the latest version but allow their input to work with the older version: that’s particularly true if you work with people using Overleaf, as it will be some time before they update to v3. You can of course just stick to the v2 interfaces, but if you’d prefer to have v3 if possible, then you will need to define \qty and \unit (and maybe others) conditionally. I’d recommend doing that using
\usepackage{siunitx}
\ifdefined\qty\else
\ifdefined\NewCommandCopy
\NewCommandCopy\qty\SI
\else
\NewDocumentCommand\qty{O{}mm}{\SI[#1]{#2}{#3}}
\fi
\fi
\ifdefined\unit\else
\ifdefined\NewCommandCopy
\NewCommandCopy\unit\si
\else
\NewDocumentCommand\unit{O{}m}{\si[#1]{#2}}
\fi
\fi
That then leaves options, but almost always these should be set in the preamble, so are a ‘one shot’. You can of course add to my tests above to know which version is in use, and set selectively.
## Working with products or complex values
For people who’ve been using products or complex numbers in \SI in v2, one could use a similar approach to the above to ‘keep’ the functionality by setting it equivalent to the new \qtyproduct or \complexqty commands: of course, if you want both then you’ve got to make bigger changes. For example, to retain the ability to use products in \SI, you’d use
\usepackage{siunitx}
\ifdefined\qtyproduct\else
\ifdefined\DeclareCommandCopy
\DeclareCommandCopy\SI\qtyproduct
\else
\DeclareDocumentCommand\SI{O{}mm}{\qtyproduct[#1]{#2}{#3}}
\fi
\fi
at the cost that the code is a bit slower than \qty for input without products. Complex values would be handed the same way, just changing the command you use as a ‘replacement’.
## Using litres (liters)
In v2, \litre and \liter produced different output: that was not the best interface decision. So in v3 they are the same, but that means of course that you might see a change. Luckily, you can set the output you want and get the same in both v2 and v3.
\DeclareSIUnit\litre{l}
#### siunitx v3
I’ve just released version 3 of siunitx: its a major update, in which the internals have largely been re-written. The following is a short(ish) summary of the major benefits and changes.
## The benefits
The major changes under the hood mean I can get better performance out of version 3 than there was in version 2. For most users, you’ll see something like a two-times speed-up of any use of siunitx. That shows up most if you have complex tables.
The new font control system means that I have to do a lot less to match the running font. So it is a lot easier to ‘do nothing’ than it was with version 2 (where basically you have to undo all of the font changes made by siunitx to get back to where you started!).
There’s new functionality across the board for number processing, and that means I can do more. Most obviously, there is now the ability to round numbers based on their uncertainties. I’ve also removed the oddities and limitations for interaction between parts of the code. Uncertainties can now be formatted using the NIST approach: a long-standing request.
For programmers, there is now a formal documented code-level API and a full set of tests (running using l3build), so it’s a lot easier to be sure what is supposed to happen. You can also re-use bits of siunitx to support other code much more easily than in the past.
Finally, I’ve now got more ability to add new features: I now know how I’m going to deal with multi-part uncertainties, for example. That includes having proper internal structures to make future development easier.
## The changes
Now to the things to watch out for: taken from the new manual, and perhaps a bit more formal than the usual blog post!
A significant number of key-value settings have new, more descriptive, names. Where possible, older names are mapped to newer ones internally: you will be warned in the log if this is the case.
It is possible to use the LaTeX kernel mechanism to load the last version 2 release for documents that cannot be successfully processed using version 3. This can be achieved using
\usepackage{siunitx}[=2021-04-09]
or
\usepackage{siunitx}[=v2]
In version 3, the document commands have been revised to be more descriptive. As such, the commands \SI,\SIlist, \SIrange and \si remain available but are not recommended for use in new use.
Some changes have been made to the semantics of commands or options. Most notably
• prefixes cannot now be given without units;
• prefixes can only be interconverted with numbers as part of a quantity, not as stand-alone units.
The font control system has been completely re-written for version 3. The method used is entirely different from version 2. Emulation is therefore not provided for some aspects: if you need non-standard font settings, you will need to adjust your source.
The input approach for version 3 is slightly more structured and restricted than for version 2. As well as the updated names for document commands, this means that
• Products of numbers must now be given using the dedicated \numproduct and \qtyproduct commands;
• Quotients of numbers are only supported as literals;
• Complex values need to be given using the dedicated command \complexnum.
The letter used for a numerical tabular column can now be selected by the user: the letter S has been retained as the standard interface. The unit column (s) has been removed from this release. It can be emulated using the collcell package, for example
\usepackage{collcell}
\newcolumntype{s}{>{\collectcell\unit}c<{\endcollectcell}}
or
\usepackage{collcell}
\newcolumntype{s}{>{\collectcell\si}c<{\endcollectcell}}
A new approach has been taken to providing non-Latin symbols for use in units: these are now handled directly where needed, for example in the definition of the \micro prefix.
If you are using table-column-width to have fixed-width columns, you also now need table-fixed-width to set this option active.
## 2021-05-16
### LaTeX.net
#### Der Online-Compiler TeXlive.net
Ursprünglich auf TeX.co veröffentlicht.
Es gibt ja viele Internet-Foren, Blogs, Wikis und andere Webseiten mit Codebeispielen für TeX und LaTeX. Gerade in Foren ist es üblich, Problem-Beispiele zu posten, und Antworten enthalten oft vollständige Lösungs-Codes. Optimalerweise mit Screenshots zum Komfort aller Leser. Man kann sich den Code herauskopieren und in seinem eigenen LaTeX-Editor ausprobieren.
Was, wenn man den Code mit einem einzigen Klick direkt auf der Webseite übersetzen könnte? Am besten auch auf dem Tablet oder Mobiltelefon, wo auch immer man gerade liest?
Das geht nun mit TeXlive.net.
Am besten sieht man es am Beispiel:
\documentclass[border=10pt]{standalone}
\usepackage{smartdiagram}
\usepackage{metalogo}
\begin{document}
\smartdiagram[bubble diagram]{\TeX\ engines,
\TeX\ (dvi), pdf\TeX, \XeTeX, \LuaTeX, Con\TeX t}
\end{document}
Einfach “Run LaTeX here” klicken. Dann übersetzt LaTeX den Code und er wird hier direkt dargestellt. Durch Klicken auf >> rechts oben kann man die PDF-Datei speichern.
Auch gut zum Testen und ausprobieren: den Code kann man hier direkt auf der Webseite editieren und wieder auf den Ausgabe-erzeugen-Schalter klicken. Das finde ich extrem praktisch in Foren, wo man ein angegebenes Problembeispiel direkt bearbeiten und testen kann, um eine Lösung zu finden und mitzuteilen. Probier einfach aus, indem Du die Diagramm-Texte oben oder das unten folgende Mathematik-Beispiel etwas editierst und erneut übersetzt.
Wie hier zu sehen, erfolgt Angabe der Engine, des Formats, oder des Ausgabeformats durch einen Kommentar
% !TEX name
wobei name z.B. sein kann: latex, pdflatex, xelatex, lualatex, pdftex, luatex, xetex, context, oder für die Ausgabe pdfjs, pdf, log (Logfile), make4ht, LaTeXML or lwarp, und Tools wie makeindex mit Parametern. Siehe auch Beispiele und Dokumentation.
Die Auslastungs-Statistik von TeXlive.net zeigt, dass täglich ungefähr 2000 verschiedene Nutzer ca. 4000 Dokumente übersetzen, an Wochenenden weniger. Das kommt daher, weil TeXlive.net schon in vielen Webseiten genutzt wird und die Nutzer aktiv die Codebeispiele ausprobieren. Hier einige willkürliche Beispiele, die zeigen, dass es auf verschiedensten Web-Plattformen läuft:
TeXlive.net unterstützt ca. 20 Compiler Engines/Formate einschließlich (pdf)LaTeX, XeLaTeX, LuaLaTeX, plain (pdf)TeX, LuaTeX, XeTeX und ConTeXt sowie Ausgabe via pdfjs, Browser PDF plugin, HTML-Ausgaben mit make4ht, lwarp, oder LaTeXML und Tools wie makeindex, BiBTeX, und biber, kombinierbar.
Warum nicht auch direkt übersetzbaren Code in Twitter-Beiträge einbetten? Das geht mit LaTeX-Dokumenten direkt in einer URL, z.B.: texlive.net/run?$T_{f(x;a)}=\sum_{n=0}^\infty\frac{f^{(n)}(a)}{n!}$.
Zum Datenschutz: TeXlive.net als Compiler erhält den übergebenen Code, übersetzt ihn und liefert die Ausgabe zurück. Die bei der Übersetzung anfallenden Dateien (PDFs, Logfiles) werden in einer stündlichen Routine gelöscht wenn sie ab 1 Stunde alt sind, d.h. sie liegen 1-2 Stunden vor bis zur automatischen Löschung. Wie bei Webseiten üblich, sieht auch TeXlive.net die IP-Adresse des Aufrufenden (bzw. seines Providers). Webserver-Logdaten (für technische Zwecke (Troublehooting, Performance-Statistik, Schutz gegen Angriffsversuche) werden nach ab 14 Tagen Alter automatisch gelöscht.
Die Software für TeXlive.net wurde von David Carlisle geschrieben, ursprünglich für LearnLaTeX.org, eine multilinguale Tutorial-Seite für LaTeX-Einsteiger, die auch den Online-Compiler in den Lektionen verwendet. Der Server arbeitet mit einem aktuellen TeX Live 2021. Wie die obengenannten Foren und weiteren Webseiten läuft TeXlive.net auf von DANTE e.V. projektfinanzierter Hardware, das sind zwei bei Hetzner laufende Root-Server. Danke an DANTE dafür.
## 2021-05-10
### Some TeX Developments (by Joseph Wright)
#### siunitx v3 beta 2
Following up on the recent first beta for siunitx, I’ve now made a second beta available. There was only one issue picked up so far by testers, plus of course those I’ve spotted myself. In particular, I’ve allowed a way to set the text font manually if simply resetting back to the standard one doesn’t work. I’ve also sneaked in a late addition: the ability to parse and print uncertainties the way NIST seem to suggest they should appear.
Assuming that I get no major issues coming up, I plan to put this out as the first v3 release in a couple of weeks time: before the next LaTeX kernel update!
## 2021-05-09
### LaTeX.net
#### LaTeX Beginners Guide Chapter 7: Cross-Referencing
Internal draft for codes.
# The third and final LaTeX pre-release for 2021-06-01 is available for testing
A few days ago we submitted a new LaTeX development format to CTAN and by now this should be available to all users using MiKTeX or TeX Live (on any operating system).
Because of the freeze for TeXLive 2021 we have decided to move the release date for LaTeX from May to June, to give everybody enough time for testing the new release features.
## Main features of the second pre-release for 2021-06-01
The final pre-release contains all the features, corrections and enhancements that we intend to release in June. The more important ones are listed in the draft publication of LaTeX2e News Issue 33. A full list is given in the changes.txt files that are part of the distribution. Notable improvements are
• better support for copy-and-paste from LaTeX-generated PDF documents by including glyphtounicode mappings;
• support for producing several footnote marks to one footnote with the help of the \footref command;
• additional support for package and class option lists that use key/value syntax;
• extending the general hook management system to paragraphs and commands as discussed below.
### Extending the general hook management system to paragraphs and commands
In addition to the bug fixes and enhancements, the next release also extends LaTeX’s general hook management system by supporting paragraph hooks executed at the beginning and end of every paragraph, documented in ltpara-doc.pdf.
This functionality is essential for the production of automatically tagged PDF documents and resolves one of the major obstacles in this area. It is thus an important step in our multi-year journey towards accessible and well-tagged PDF documents. See articles in PDF, Tagging, Accessibility.
Even though this new functionality may not be of direct interest to most users (as long as it is not yet used for processing accessible PDF) it is nevertheless important that it gets tested to ensure that there aren’t any conflicts with existing packages that also try to manipulate the paragraph processing in one way or the other. So please make use of the development format whenever you have a chance, see below for how to do this with ease.
The release will also support generic hooks on all user-level commands; in theory that is, in practice there are some restrictions as explained in the documentation in ltcmdhooks-doc.pdf.
Again this is an important step towards tagged PDF as it will help integrating the necessary code in various user-level commands without extensive code alterations that would otherwise be required. In addition this functionality is also of interest to packages that for one or the other reason currently patch code of other packages or from the kernel as the hook management helps to do this in controlled ways avoiding typical incompatibilities between packages.
### Kernel support for the new LaTeX PDF management
We also added the necessary support in the LaTeX kernel and uploaded the new LaTeX PDF management — so far as a separate package for testing. This code is another important step towards well-tagged PDF documents as it provides backend-independent interfaces to central PDF dictionaries, tools to create annotations, form Xobjects, to embed files, and to handle PDF standards. During a test phase this code is provided through an external package named pdfmanagement-testphase. Please help with the testing here too. You can access the documentation through texdoc pdfmanagement-testphase.
## Outlook
This is the final prerelease, the same code (modulo any corrections found during testing) is planned as the official June 2021 release.
We are issuing this final pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.
This development format allows you to test the upcoming LaTeX release scheduled for 2021-06-01 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.
Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release in June hits the streets.
Processing your documents with the pre-release is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
If you encounter any issue with this prerelease, please open a bug report at https://github.com/latex3/latex2e/issues following the guidelines given there (especially providing a processable test document).
In case of incompatibility problems with the prerelease it is, of course, acceptable to report them to us, even if \RequirePackage{latexbug} tells you to report them elsewhere (it would help if you do that too).
Enjoy — Frank
## 2021-04-16
### Some TeX Developments (by Joseph Wright)
#### siunitx v3 beta
I’ve been talking about a new version of siunitx for ages. Progress has been slow but I’ve now put my back into it and got to a feature-complete version: I’m calling this v3.0.0-beta. As this is a beta release, it’s not ready for production just yet, but it is ready for proper testing. I’ve made the TDS-style zip file available here; if you know how to use this kind of file, please download and test!
As I’ve said before, there are a lot of internal improvements in the code. There are also some big changes which do show to users. The major changes are
• The name for commands for units and quantities have changed: \unit and \qty. The old names (\si and \SI) are still about, but I’d encourage people to move to the new ones.
• Font set up is entirely revised, which means that there are new settings to use if you want to adjust the output. The new approach should be faster and cleaner than the old one, but you might have to pick new options.
• Products of numbers now have a dedicated interface: \numproduct, with a matching \qtyproduct for quantities
• Complex numbers also have decided interfaces: \complexnum and \complexqty: this makes parsing a lot easier
• A small number of ideas have been removed: most notably parsing quotients
• I’ve updated the units provided to match the 9th SI Brochure: that means a few units are removed (for example ängström and bar)
To support users and to avoid breaking any documents, the new code is accompanied by a (likely) final version 2 file. That can be loaded using
\usepackage{siunitx}[=v2]
where needed.
What I’m looking for now is feedback on what works, what I’ve missed, etc. Feedback is best in issues on GitHub. You might notice I’m already planning v3.1 and v3.2: the new structures should make more development possible. But at the moment I’m mainly trying to finalise v3.0.
## 2021-04-08
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Gittermuster erstellen mit gridpapers
Hier ein Beispiel dafür, wie man mit dem gridpapers Paket Muster auf Papier bringen kann, hier ein Punktmuster.
%!TEX TS-program = Arara
% arara: pdflatex: {shell: yes}
\documentclass[12pt,ngerman]{scrartcl}
\areaset{8cm}{16cm}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{babel}
\pagestyle{empty}
\usepackage[pattern=dot,%
colorset=std,
geometry={left=2.25cm,right=1.25cm,top=1cm,bottom=1.25cm},%
textarea,%
patternsize={5mm},%
dotsize={1pt}
]{gridpapers}
\begin{document}
~
\end{document}
Auszug aus der A4-Seite:
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2021-03-13
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Dymo Labels mit LaTeX und ticket.sty gestalten
Hier ein kurzes Beispiel, wie man mit LaTeX auch Dymo-Labels erzeugen kann, im Beispiel für die Label-Größe 57*32mm. Zum allgemeinen Verständnis von ticket.sty siehe auch meinen DTK Artikel in Ausgabe 1/2021.
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage[landscape,paperheight=57mm,paperwidth=32mm,left=0mm,top=0mm,right=0mm,bottom=0mm]{geometry}
%\usepackage[sfdefault]{plex-sans}
\usepackage{palatino}
\begin{filecontents}[overwrite]{Dymo5732.tdf}
\unitlength=1mm
\hoffset=-25.4mm
\voffset=-29mm
\ticketNumbers{1}{1}
\ticketSize{57}{32} % Breite und Hoehe der Labels in mm
\ticketDistance{0}{0} % Abstand der Labels
\end{filecontents}
\usepackage[Dymo5732]{ticket}
\renewcommand{\ticketdefault}{}%
\makeatletter
\@boxedfalse % Rahmen um Ticket
\@emptycrossmarkfalse % Falzmarken
\@cutmarkfalse % Schnittmarken
\makeatother
\newcommand{\myticket}[2]{
\ticket{%
\put(10,10){\scalebox{#1}{\bfseries #2}}
}}
\newcommand{\myticketml}[4]{
\ticket{%
\put(5,20){\scalebox{#1}{\bfseries #2}}
\put(5,15){\scalebox{#1}{\bfseries #3}}
\put(5,10){\scalebox{#1}{\bfseries #4}}
}}
\begin{document}
\myticket{2}{Steuern}
\end{document}
PDF
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2021-03-09
### LaTeX.net
#### Compiling LaTeX online via TeXlive.net
Blogs, forums, Q&A sites, FAQ sites, and web sites in general can now provide one-click LaTeX compiling on smartphones, tablets, and PCs.
The TeXlive.net server provides a backend with a TeX Live 2020 installation. The server software was written by David Carlisle and is hosted on a virtual machine provided by Stefan Kottwitz, with financial support from DANTE for the hardware.
The tutorial site LearnLatex.org already switched to TeXlive.net.
That’s how it looks like on a web page:
\documentclass[border=10pt]{standalone}
\usepackage{smartdiagram}
\begin{document}
\smartdiagram[descriptive diagram]{
and line styles for nodes and arrows}},
{Position, {Place nodes using a matrix,
relative or absolute positioning}},
{Relation, Insert edges or arrows
between selected nodes},
{Label, Add labels on edges or arrows}}
\end{document}
Click on “Run LaTeX here” to open an embedded PDF viewer with the document output. And yes, you can edit the document right on the web page and compile again.
TeXLive.net, LaTeX.net and many further web sites are supported by DANTE e.V., the German language user group. Our 2021 DANTE spring meeting starts today, join us!
## 2021-03-07
### LaTeX.net
#### DANTE Frühjahrstagung 2021
The following text is in German because it’s about the German language user group meeting 2021.
Im vergangenen Jahr sind leider beide DANTE-Tagungen wegen der Pandemie ausgefallen.
Dieses Jahr wird die Frühjahrstagung stattfinden, jedoch wegen der Kontaktbeschränkungen komplett online.
Anmelden kann man sich online auf www.dante.de/veranstaltungen/dante2021/anmeldung/ und das ist kurz und einfach und kostenfrei.
Mitglieder erhalten später einen PIN-Code, mit dem man sich an Abstimmungen während der Mitgliederversammlung beteiligen kann. Wie es geht, wird dann in der Versammlung erläutert.
Wichtig: Die Anmeldung sollte bis spätestens Dienstag erfolgen.
Das Programm, vom 9. bis 11. März 2021:
• Dienstag, 9.3.: ab 19:30 Uhr Vorabendtreff
• Mittwoch,10.3.: 17 Uhr Begrüßung, danach 3 Vorträge zu
• Spaß mit LaTeX für Zuhaus-Unterricht, Videokonferenzen und mehr
• Lehr-Unterstützung durch automatisiert generierte personalisierte Aufgaben und Lösungen
• PDF Ressourcen-Management mit LaTeX als Baustein für barrierefreies PDF
• Donnerstag, 11.3.: ab 9 Uhr Mitgliederversammlung, danach Vorträge bis ca. 19 Uhr zu
• GUST e-foundry Schriftprojekt
• TikZ-Zeichnungen
• englischsprachiger TeX Frage/Antwort-Webseite
• Erstellen von ausfüllbaren PDF-Formularen mit LaTeX
• Erzeugung von TeX-Ausgaben aus XML
• Automatisiertem Tabellensatz aus XML und LaTeX
Siehe auch Programm und Tagungs-Seite.
Wie läuft das ab?
Basis ist die Videokonferenz-Software Zoom, lizensiert durch die Universität Magdeburg als Veranstalter. Teilnehmer erhalten einen Zugangs-Link mit Meeting-ID und Kennwort. Darüber kann man sich einloggen und mit einem Webbrowser oder der Zoom-App auf dem PC oder dem Handy teilnehmen. Da hat man zunächst einfach mal das passive Zuschauen und Zuhören der Vorträge, weiterhin kann man aber auch in aktive Räume wechseln zum Unterhalten in kleinerem Kreis. Das sieht man dann schon.
Das Teilnehmen sollte recht einfach sein – kommt dazu! Die Organisation war und ist bestimmt herausfordernd – vielen Dank an Mathias Magdowski, Martin Sievers, weitere Organisatoren und den Vorstand, und an die Vortragenden!
An dieser Stelle auch ein Danke von mir an DANTE für die Unterstützung bei den Serverkosten dieser Webseite LaTeX.net sowie der LaTeX-Foren TeXwelt.de, goLaTeX.de, LaTeX.org, TeXnique.fr, und weiteren Webseiten wie TeXfragen.de, LaTeX.net.br, TeXdoc.org, CTAN.net, TeXlive.net, TeX.my, TeXample.net, pgfplots.net, TeX-talk.net, mychemistry.eu, TeX.co, TeXblog.net und weiteren.
Photo by Raphael Schaller on Unsplash
# The second LaTeX pre-release for 2021-05-01 is available for testing
A few days ago we submitted a new LaTeX development format to CTAN and by now this should be available to all users using MiKTeX or TeX Live (on any operating system).
## Main features of the second pre-release for 2021-05-01
The first pre-release was just a copy of the main release for 2020-10-01 in order to avoid that people using the development release regularly get an old format.
The second pre-release now provides a number of smaller enhancements and resolves roughly forty issues. The more important ones are listed in the draft publication of LaTeX2e News Issue 33. A full list is given in the changes.txt files that are part of the distribution. Notable improvements are
• better support for copy-and-paste from LaTeX-generated PDF documents by including glyphtounicode mappings;
• support for producing several footnote marks to one footnote with the help of the \footref command;
• additional support for package and class option lists that use key/value syntax;
• extending the general hook management system to paragraphs as discussed below.
### Extending the general hook management system to paragraphs
In addition to the bug fixes and enhancements, this second pre-release also extends LaTeX’s general hook management system by supporting paragraph hooks executed at the beginning and end of every paragraph.
This functionality is essential for the production of automatically tagged PDF documents and resolves one of the major obstacles in this area. It is thus an important step in our multi-year journey towards accessible and well-tagged PDF documents. See articles in PDF, Tagging, Accessibility.
Even though this new functionality may not be of direct interest to most users (as long as it is not yet used for processing accessible PDF) it is nevertheless important that it gets tested to ensure that there aren’t any conflicts with existing packages that also try to manipulate the paragraph processing in one way or the other. So please make use of the development format whenever you have a chance, see below for how to do this with ease.
### Kernel support for the new LaTeX PDF management
We also added the necessary support in the LaTeX kernel and uploaded the new LaTeX PDF management — so far as a separate package for testing. This code is another important step towards well-tagged PDF documents as it provides backend-independent interfaces to central PDF dictionaries, tools to create annotations, form Xobjects, to embed files, and to handle PDF standards. During a test phase this code is provided through an external package named pdfmanagement-testphase. Please help with the testing here too. You can access the documentation through texdoc pdfmanagement-testphase.
## Outlook
We expect to produce a third and probably final pre-release adding some more features and enhancements in early April.
We are issuing this second pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.
This development format allows you to test the upcoming LaTeX release scheduled for 2021-05-01 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.
Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release in May hits the streets.
Processing your documents with the pre-release is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
Enjoy — Frank
## 2021-02-24
### TUG
#### TUG election deadline of March 1
Nominations for the TeX Users Group election for this year are due March 1 (7am PST; no extensions or exceptions). The positions of TUG president and of several directors are up for election. A nomination form and full details are available.
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Nützliche Kommandozeilen-Einzeiler für LaTeX
Unter https://gist.github.com/iwishiwasaneagle/2f91f63f3cb0107b94b501aa284a18ca gibt es eine Sammlung an nützlichen Einzeilern für die Arbeit mit LaTeX.
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2021-02-14
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Aktienkurse mit Python und LaTeX auswerten
Hier ein einfaches Beispiel, wie man mit Python und LaTeX ein PDF mit Kursinformationen erstellen kann.
Zuerst der Python-Teil, der die Apple-Kursdaten seit dem 1.1.2021 in einen Dataframe lädt und dann in eine LaTeX-Tabelle schreibt:
import pandas
history.to_latex('aapl.tex')
Dann noch der LaTeX-Teil, der a) den Python-Code aus dem LaTeX-Lauf heraus ausführt und b) die erzeugte Tabellen-Datei nur dann einbindet, wenn sie wirklich auch erzeugt wurde.
\documentclass[12pt,ngerman]{scrartcl}
\usepackage[a4paper, top=1cm,bottom=1cm,left=1cm, right=1cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage{booktabs}
\makeatletter
\newcommand{\testfileexists}[1]{%
\IfFileExists{#1}%
{\def\inputtestedfile{\@@input #1 }}
{\let\inputtestedfile\@empty}%
}
\makeatother
\begin{document}
\write18{python runpy.py}
\testfileexists{aapl}
\inputtestedfile
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
# A new team member?
In these rather dark times, some light-hearted news.
Courtesy of Paulo Cereda (the designer of our hummingbird) a picture of his pet camouflaging himself as a project member:
Looking forward to his contributions. — Enjoy Frank
## 2020-12-23
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Farbige Boxen in LaTeX mit tcolorbox
Hier einige Beispiele für farbige Boxen mit dem tcolorbox Paket, entnommen der Paketbeschreibung
\documentclass[12pt,ngerman]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{booktabs}
\usepackage{babel}
\usepackage{graphicx}
\usepackage{csquotes}
\usepackage{paralist}
\usepackage{xcolor}
\usepackage{blindtext}
\usepackage{microtype}
\usepackage{empheq}
\usepackage[most]{tcolorbox}
\tcbuselibrary{theorems}
\newtcbtheorem[number within=section]{mytheo}{My Theorem}%
{colback=green!5,colframe=green!35!black,fonttitle=\bfseries}{th}
\begin{document}
\begin{tcolorbox}
Hallo Welt!
\end{tcolorbox}
\begin{tcolorbox}
\blindtext
\end{tcolorbox}
This is another \textbf{tcolorbox}.
\tcblower
Here, you see the lower part of the box.
\end{tcolorbox}
\begin{mytheo}{This is my title}{theoexample}
This is the text of the theorem. The counter is automatically assigned and,
in this example, prefixed with the section number. This theorem is numbered with
\ref{th:theoexample}, it is given on page~\pageref{th:theoexample}.
\end{mytheo}
$$\tcbset{fonttitle=\footnotesize} \tcboxmath[colback=yellow!25!white,colframe=blue]{ a^2 = 16 } \quad \Rightarrow \quad \tcboxmath[colback=blue!25!white,colframe=red,title=Implication]% { a = 4 ~\vee~ a=-4. }$$
\newtcbox{\otherbox}[1][]{nobeforeafter,math upper,tcbox raise base,
enhanced,frame hidden,boxrule=0pt,interior style={top color=green!10!white,
bottom color=green!10!white,middle color=green!50!yellow},
fuzzy halo=1pt with green,#1}
\begin{empheq}[box=\otherbox]{align}
a&=\sin(z)\\
E&=mc^2 + \int_a^b x\, dx
\end{empheq}
$$\tcbhighmath{E} = \otherbox{mc^2}$$
\newtcolorbox{mybox}[2][]{colback=red!5!white,
colframe=red!75!black,fonttitle=\bfseries,
colbacktitle=red!85!black,enhanced,
attach boxed title to top center={yshift=-2mm},
title=#2,#1}
\begin{mybox}[colback=yellow]{Hello there}
This is my own box with a mandatory title
and options.
\end{mybox}
\begin{tcolorbox}[enhanced,
size=minimal,auto outer arc,
width=2.1cm,octogon arc,
colback=red,colframe=white,colupper=white,
fontupper=\fontsize{6mm}{6mm}\selectfont\bfseries\sffamily,
halign=center,valign=center,
square,arc is angular,
borderline={0.2mm}{-1mm}{red} ]
STOP
\end{tcolorbox}
\begin{tcolorbox}[enhanced,
size=minimal,auto outer arc,
width=2.1cm,octogon arc,
colback=green,colframe=white,colupper=black,
fontupper=\fontsize{6mm}{6mm}\selectfont\bfseries\sffamily,
halign=center,valign=center,
square,arc is angular,
borderline={0.2mm}{-1mm}{green}]
GO
\end{tcolorbox}
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2020-12-22
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Kurszertifikate mit LaTeX erstellen
Das pgfornaments Paket erlaubt es, spezielle Schmuckzeichen für beispielsweise Kurszertifikate zu nutzen. Hier ein Beispiel, das ich gern für die Teilnehmerinnen und Teilnehmer meiner LaTeX-Kurse nutze.
\documentclass[16pt,ngerman]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{booktabs}
\usepackage{eso-pic,calc}
\usepackage{babel}
\usepackage{graphicx}
\usepackage{csquotes}
\usepackage{paralist}
\usepackage{xcolor}
\usepackage[a4paper,landscape,bottom=1.5cm]{geometry} % left=0pt,right=0pt,top=0pt,bottom=0pt
\usepackage{palatino,dashrule}
\usepackage{pgfornament}
\pagestyle{empty}
\setlength{\parindent}{0pt}
\makeatletter
\begingroup
\setlength{\@tempdima}{5mm}%
\setlength{\@tempdimb}{\paperwidth-\@tempdima-3cm}%
\setlength{\@tempdimc}{\paperheight-\@tempdima}%
\put(\LenToUnit{\@tempdima},\LenToUnit{\@tempdimc}){%
\pgfornament[color=magenta,anchor=north west,width=3cm]{63}}
\put(\LenToUnit{\@tempdima},\LenToUnit{\@tempdima}){%
\pgfornament[color=magenta,anchor=south west,width=3cm,symmetry=h]{63}}
\put(\LenToUnit{\@tempdimb},\LenToUnit{\@tempdima+\paperheight-1cm}){%
\pgfornament[color=magenta,anchor=north east,width=3cm,symmetry=v]{63}}
\put(\LenToUnit{\@tempdimb},\LenToUnit{\@tempdima+\paperheight-21cm}){%
\pgfornament[color=magenta,anchor=south east,width=3cm,symmetry=c]{63}}
\endgroup
}
\let\strippt\strip@pt
\makeatother
\begin{document}
\centering\Huge
\textbf{Zertifikat}
\vspace{20mm}
\begin{center}
Max Mustermann%\hdashrule[0.75ex]{14cm}{1pt}{3mm}
\end{center}
\vspace{1cm}\huge
hat erfolgreich am zweitägigen \LaTeX-Kurs der Musteruni teilgenommen. \vspace{2cm}\LARGE\flushleft
Musterau, \hfill\hdashrule[0.75ex]{9.5cm}{1pt}{2mm}
\today
\begin{center}
\vfill\pgfornament[width=0.7\textwidth]{88}
\end{center}
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
#### Schöne Matrizen mit nicematrix
Um ansprechende Matrizen zu setzen gibt es mit dem nicematrix Paket ein recht neues Paket, das sich alle anschauen sollten, die viel mit Matrizen zu tun haben. Die folgenden Beispiele sind der Dokumentation entnommen, teilweise braucht man mehrere LaTeX-Läufe für das finale Ergebnis.
%!TEX TS-program = Arara
% arara: pdflatex: {shell: yes}
\documentclass[12pt,ngerman]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage{xcolor}
\usepackage{tikz}
\usepackage{siunitx}
\usepackage{nicematrix}
\NiceMatrixOptions{cell-space-top-limit = 1pt,cell-space-bottom-limit = 1pt}
\begin{document}
$$\begin{pmatrix} \frac12 & -\frac12 \\ \frac13 & \frac14 \\ \end{pmatrix} = \begin{pNiceMatrix} \frac12 & -\frac12 \\ \frac13 & \frac14 \\ \end{pNiceMatrix}$$
$$A = \begin{pNiceMatrix}[baseline=2] \frac{1}{\sqrt{1+p^2}} & p & 1-p \\ 1 & 1 & 1 \\ 1 & p & 1+p \end{pNiceMatrix}$$
\NiceMatrixOptions{cell-space-top-limit=1pt,cell-space-bottom-limit=1pt}
$$A=\begin{pNiceArray}{cc|cc}[baseline=line-3] \dfrac1A & \dfrac1B & 0 & 0 \\ \dfrac1C & \dfrac1D & 0 & 0 \\ \hline 0 & 0 & A & B \\ 0 & 0 & D & D \\ \end{pNiceArray}$$
$$\begin{NiceArray}{*{5}{c}}[hvlines] \diagbox{x}{y} & e & a & b & c \\ e & e & a & b & c \\ a & a & e & c & b \\ b & b & c & e & a \\ c & c & b & a & e \end{NiceArray}$$
\NiceMatrixOptions{code-for-first-row = \color{red},
code-for-first-col = \color{blue},
code-for-last-row = \color{green},
code-for-last-col = \color{magenta}}
$$\begin{pNiceArray}{cc|cc}[first-row,last-row=5,first-col,last-col,nullify-dots] & C_1 & \Cdots & & C_4 & \\ L_1 & a_{11} & a_{12} & a_{13} & a_{14} & L_1 \\ \Vdots & a_{21} & a_{22} & a_{23} & a_{24} & \Vdots \\ \hline & a_{31} & a_{32} & a_{33} & a_{34} & \\ L_4 & a_{41} & a_{42} & a_{43} & a_{44} & L_4 \\ & C_1 & \Cdots & & C_4 & \end{pNiceArray}$$
$$\begin{pNiceArray}{ScWc{1cm}c}[nullify-dots,first-row] {C_1} & \Cdots & & C_n \\ 2.3 & 0 & \Cdots & 0 \\ 12.4 & \Vdots & & \Vdots \\ 1.45 \\ 7.2 & 0 & \Cdots & 0 \end{pNiceArray}$$
$\begin{NiceMatrix}[ code-before = { \tikz \draw [fill = red!15] (row-7-|col-4) -- (row-8-|col-4) -- (row-8-|col-5) -- (row-9-|col-5) -- (row-9-|col-6) |- cycle ; } ]1 \\ 1 & 1 \\ 1 & 2 & 1 \\ 1 & 3 & 3 & 1 \\ 1 & 4 & 6 & 4 & 1 \\ 1 & 5 & 10 & 10 & 5 & 1 \\ 1 & 6 & 15 & 20 & 15 & 6 & 1 \\ 1 & 7 & 21 & 35 & 35 & 21 & 7 & 1 \\ 1 & 8 & 28 & 56 & 70 & 56 & 28 & 8 & 1 \end{NiceMatrix}$
$$\begin{bNiceMatrix} C[a_1,a_1] & \Cdots & C[a_1,a_n] & \hspace*{20mm} & C[a_1,a_1^{(p)}] & \Cdots & C[a_1,a_n^{(p)}] \\ \Vdots & \Ddots & \Vdots & \Hdotsfor{1} & \Vdots & \Ddots & \Vdots \\ C[a_n,a_1] & \Cdots & C[a_n,a_n] & & C[a_n,a_1^{(p)}] & \Cdots & C[a_n,a_n^{(p)}] \\ \rule{0pt}{15mm} & \Vdotsfor{1} & & \Ddots & & \Vdotsfor{1} \\ C[a_1^{(p)},a_1] & \Cdots & C[a_1^{(p)},a_n] & & C[a_1^{(p)},a_1^{(p)}] & \Cdots & C[a_1^{(p)},a_n^{(p)}] \\ \Vdots & \Ddots & \Vdots & \Hdotsfor{1} & \Vdots & \Ddots & \Vdots \\ C[a_n^{(p)},a_1] & \Cdots & C[a_n^{(p)},a_n] & & C[a_n^{(p)},a_1^{(p)}] & \Cdots & C[a_n^{(p)},a_n^{(p)}] \end{bNiceMatrix}$$
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
#### Das subcaption Paket als subfigure Ersatz
Um mehreren nebeneinander gesetzten Bildern separate Bildunterschriften zu geben, war das subfigure Paket lange Standard. Mit dem subcaption Paket von Axel Sommerfeldt gibt es einen würdigen Nachfolger, der aktiv gepflegt wird.
Hier ein Beispiel, zum Übersetzen bitte eigene Bilder nutzen:
\documentclass[12pt,ngerman]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage{graphicx}
\usepackage{subcaption}
\begin{document}
\begin{figure}
\centering
\subcaptionbox{Eine Katze \label{cat1}}
{\includegraphics[width=0.49\textwidth]{Bilder/Katze1}}
\subcaptionbox{Die selbe Katze \label{cat2}}
{\includegraphics[width=0.49\textwidth]{Bilder/Katze2}}
\caption{Zwei Katzenbilder}\label{katzenbilder}
\end{figure}
Abbildung \ref{cat1} auf Seite \pageref{katzenbilder}
Abbildung \ref{cat2} auf Seite \pageref{katzenbilder}
Abbildung \ref{katzenbilder} auf Seite \pageref{katzenbilder}
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
#### Flyer mit LaTeX gestalten
Um einen einfachen Flyer zu erstellen gibt es nichts besseres als die leaflet-Klasse. Hier ein einfaches Beispiel, die Katzenbilder muss man zum Übersetzen auskommentieren oder ersetzen.
\documentclass[12pt,ngerman]{leaflet}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{booktabs}
\usepackage{babel}
\usepackage{graphicx}
\usepackage{csquotes}
\usepackage{paralist}
\usepackage{xcolor}
\usepackage{palatino}
\usepackage{blindtext}
\usepackage{microtype}
\author{Uwe Ziegenhagen}
\title{Mein erster Flyer}
\begin{document}
\maketitle
\thispagestyle{empty}
\section{Foo}
\blindtext[2]
\section{Bar}
\includegraphics[width=\textwidth]{Bilder/Katze2}
\blindtext
\section{Hello}
\blindtext[4]
\section{World}
\blindtext
\section{Hallo Welt}
\blindtext
\includegraphics[width=\textwidth]{Bilder/Katze1}
\end{document}
leaflet-01
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2020-12-18
### Weblog von Markus Kohm
#### Alle Jahre wieder …
Hallo,
es ist ja fast so etwas wie eine Tradition, am Jahresende für alles mögliche zu Spenden aufzurufen. Ich bin da keine Ausnahme. Seit Jahren bitte ich immer mal wieder zu dieser Zeit, um Unterstützung für den Betrieb des Servers, auf dem komascript.de gehosted wird. Viele nehmen das dann auch zum Anlass, meine Wunschliste zu durchforsten und mir ein persönliches Geschenk zukommen zu lassen. Dieses Jahr soll das ein wenig, aber nicht ganz anders sein.
Während dieses Jahr für viele ein sehr hartes Jahr war, bin ich persönlich und auch meine Familie vergleichsweise gut bis hierher gekommen. Obwohl auch wir nicht von Covid-19 und anderen Krankheiten verschont blieben, bleibt mir vor allem die Solidarität, die wir dabei erfahren haben, in Erinnerung. Während andere sich über Maskenpflicht und Abstandsregeln aufgeregt haben, habe ich schlicht bedauert, dass dergleichen notwendig ist. Vielleicht ist es einfach leichter, dergleichen zu akzeptieren, wenn man unmittelbar erlebt hat, wie sogar bei relativ leichtem Verlauf, die Krankheit selbst eine weit größere Belastung ist als all diese Maßnahmen. Vielleicht bin ich auch einfach gewohnt, Kontakte auf Distanz zu pflegen. Dass mir das eine oder andere Hobby quasi weggebrochen ist, hatte schließlich den Vorteil, dass ich mich auf andere Dinge konzentrieren konnte.
Aber, wie gesagt, ich kenne auch Menschen, die nicht so leicht durch dieses Jahr gekommen sind. Nicht nur persönliche Freunde haben in diesem Jahr extreme Schicksalsschläge erlitten und leiden noch immer darunter. In aller Welt gibt es Menschen, die schon ohne Pandemie tagtäglich, um ihre Zukunft ringen. Durch die Pandemie ist dieses Los zusätzlich erschwert. Unter den Schwachen sind Kinder die Schwächsten. Jahr für Jahr ist mir deshalb die Sternsingeraktion ein besonderes Anliegen. Normalerweise ziehen in der Zeit von Weihnachten bis Dreikönig Kinder von Tür zu Tür und sammeln Spenden unter dem Motto: Kinder helfen Kindern. Mit dem Geld werden weltweit unterschiedliche Projekte unterstützt, die unmittelbar die Situation von Kindern verbessern helfen. Jedes Jahr wird ein Projekt besonders hervorgehoben. In diesem Jahr ist das die Hilfe für Kinder in der Ukraine. Normalerweise kommen dank des überwältigenden Engagements von einigen ehrenamtlichen Erwachsenen, aber vor allem vieler, vieler engagierter Kinder und spendenwilligen Erwachsenen aber auch Kindern(!) allein in unserer kleinen Gemeinde dadurch jährlich mehrere Tausend Euro zusammen. Im letzten Jahr waren es insgesamt 62,6 Mio. Euro für 1623 Projekte in 108 Ländern. Für die Empfängerprojekten ist das deutlich mehr als ein Tropfen auf den heißen Stein. In diesem Jahr ist auch das anders. Die Diözese Freiburg hat kurzfristig selbst das Einwerfen von Flyern mit Spendenaufrufen zur Sternsingeraktion in die Briefkästen wegen Corona vorerst untersagt. Es ist zu befürchten, dass damit eine wirklich wichtige Aktion, die mir sehr am Herzen liegt, weitgehend ausfällt. Daher habe ich beschlossen, dieses Jahr (erneut) darum zu bitten, mir eine persönliche Freude dadurch zu machen, zum Jahresende 2020 und zum Jahresanfang 2021 mich durch eine Spende an die Sternsingeraktion 2020/21 zu beschenken. Der Link führt direkt zur Sternsingersammlung meiner Seelsorgeeinheit. Auch 5€ können bereits helfen. Ich selbst erfahre natürlich nicht, wer da was gespendet hat. Wer mir einfach formlos mitteilt, dass er meinem Aufruf gefolgt ist und deshalb auch gerne auf meine Sponsorenliste möchte, den nehme ich natürlich gerne trotzdem in selbige auf. Beträge will ich gar keine wissen. Ihr könnt euch übrigens auch digital von den Sternsingern besuchen lassen.
Bitte seid in dieser Ausnahmezeit solidarisch. Wenn ihr gesund seid, wünsche ich euch es zu bleiben. Wenn ihr es leider nicht seid, wünsche ich euch, rasche und vollständige Genesung. Achtet auf euch selbst und noch viel mehr auf andere.
Bis demnächst
Markus
## 2020-12-05
### TeX & Friends (by Jürgen Fenn)
#### The future of text
Ein Lesetipp für die kommenden Wochen dürfte dieses Werk sein:
• Hegland, Frode, Hrsg. 2020. The Future of Text. 1. Auflage. Future Text Publishing. doi:10.48197/fot2020a, (zugegriffen: 5. Dezember 2020).
Worum geht es?
Welcome to Future Text Publishing, producers of ‘The Future of Text’, the largest survey of the future(s) of text ever undertaken.
The book is a collection of dreams for how we want text to evolve as well as how we understand our current textual infrastructures, how we view the history of writing, and much more. The aim is to make it inspire a powerfully rich future of text in a multitude of ways today and to still have value in a thousand years and beyond. It should serve as a record for how we saw the medium of text and how it relates to our world, our problems and each other in the early twenty first century.
Und das ganze ist open end angelegt. Die zweite Auflage wird ab Februar 2021 vorbereitet.
# Tagged PDF feasibility study published
At the TUG 2020 online conference we announced the start of a multi-year project to automatically generate tagged PDF with LaTeX, which is an important aspect of producing “accessible” documents. Back then we promised that further information about the project is forthcoming.
We have now added the feasibility study (which was the starting point for the project) to this website:
### LaTeX Tagged PDF Feasibility Evaluation Study
This forty-page document contains information about a multi-year project, started by the LaTeX Project Team in 2020, that will extend LaTeX to produce tagged, and hence accessible, PDF with minimal manual intervention. It explains in detail both the project goals and the tasks that need to be undertaken, concluding with a detailed project plan. It is our blueprint for for how we think the project should be undertaken.
The Introduction contains an overview of the benefits of the project and explains why LaTeX documents make a good starting point for the production of tagged PDF. More information about this blueprint and the project can be found in the article “LaTeX Tagged PDF — A blueprint for a large project” TUGboat, Volume 41-3 (2020), which will appear shortly.
The original version of this study dates from late 2019 and was addressed primarily to an audience within Adobe which consisted of engineers and managers with a wide knowledge of digital typography and electronic publishing but not necessarily much background within the specialized world of TeX, LaTeX and friends. This version of the study was updated in September 2020 with some minor redactions, corrections and clarifications.
In addition the TUGboat article referred to above is also available for reading:
### LaTeX Tagged PDF — A blueprint for a large project
• Frank Mittelbach
• Chris Rowley
• TUGboat 41:3, 2020
• Abstract
In Frank’s talk at the TUG 2020 online conference we announced the start of a multi-year project to enhance LaTeX to fully and naturally support the creation of structured document formats, in particular the “tagged PDF” format as required by accessibility standards such as PDF/UA.
In this short article we outline the background to this project and some of its history so far. We then describe the major features of the project and the tasks involved, of which more details can be found in the Feasibility Study that was prepared as the first part of our co-operation with Adobe.
This leads on to a description of how we plan to use the study as the basis for our work on the project and some details of our planned working methodologies, illustrated by what we have achieved so far and leading to a discussion of some of the obstacles we foresee.
Finally there is also a summary of recent, current and upcoming activities on and around the project.
You will find both documents, as well as other documents about the “Tagged PDF Project” and related topics, on the PDF, Tagging and Accessibility page in the publications area of the site.
## 2020-11-15
### TUG
#### TUGboat 41:3 published
TUGboat volume 41, number 3, a regular issue, has been mailed to TUG members. It is also available online and from the TUG store. In addition, prior TUGboat issue 41:2 is now publicly available. Submissions for the next issue are welcome; the deadline is March 31 (early submissions are especially appreciated). Please consider joining or renewing your TUG membership if you haven't already (you'll get this issue immediately), and thanks.
# Tutorial on the L3 programming layer (expl3)
In Spring 2020 the LaTeX3 programming language expl3 was integrated into the LaTeX format to make it directly accessible to package developers and for future LaTeX kernel programming. Since that date LaTeX announces itself with something like
LaTeX2e <2020-10-01> patch level 2
L3 programming layer <2020-10-27> xparse <2020-03-03>
Up to now the documentation for expl3 that we provide consists of a short introduction (expl3.pdf), its reference manual (interface3.pdf) and its source code (source3.pdf) all of which you can easily access using the texdoc program, e.g.,
texdoc interface3
What was missing, however, was a tutorial to help progammers to get familiar with the features and approaches when they want to use the L3 programming layer in their own packages. Such a tutorial has now been written by Ziyue “Alan” Xiang, currently a PhD student at Purdue University and we strongly recommend to check it out if you are interested in L3 programming or in understanding code written in it:
Thanks Alan for your work; it is much appreciated!
Enjoy — Frank
## 2020-11-02
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Warum TeXworks manchmal nicht die PDF Anzeige aktualisiert / When TeXworks does not update the PDF
Vor einiger Zeit fiel mir auf, dass TeXworks die PDF-Anzeige manchmal nicht aktualisiert. Wann genau dies aber geschah und wann nicht, konnte ich aber nicht feststellen. Gestern schließlich brachte eine Google-Suche nach „texworks not refreshing the pdf“ eine TSX-Frage [1] ans Licht, in der der Autor dieses Fehlverhalten untersucht hatte: Das PDF wurde immer dann nicht aktualisiert, wenn die entsprechende TeX-Datei im Wurzelverzeichnis eines Laufwerks lag. Muss man erst einmal drauf kommen…
Ein Bug-Request [2] war schnell geschrieben, in der neuesten Development-Version ist dieser Bug bereits gefixt.
English Summary
In TeXworks (at least in version 0.6.5) the PDF is not updated after compilation if the TeX file had been placed in a top-level directory. A bug report was raised, it will be fixed in future versions.
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2020-10-31
### LaTeX.net
#### Happy Helloween!
Lockdown is coming in Germany.
Time for some virtual Helloween. Did you visit CTAN today? Browse it if you are not scared!
And if you wonder what helloweenmath (in the article header image) is about – that’s today’s maths style. Examples from the manual:
# The fall 2020 LaTeX release is available
This release introduces a number of important enhancements.
### A general hook management system for LaTeX
Most LaTeX users and package writers will know the handful of hooks that LaTeX has been offering until now, the most important one perhaps being \AtBeginDocument. These are important hooks, but they are far too few so that in many cases package developers had to directly patch the internals of LaTeX. This resulted in many problems.
With the new hook management system, LaTeX will get many more hooks that package writers (and authors) can use to add code in a controlled and reliable way. New hooks have been added in a number of places by using the new system and more will follow over time. Available now are:
• Hooks to add code before and after environments (formerly offered through the etoolbox package);
• Hooks used when loading files, packages, or classes (similar to what the filehook package now provides);
• Hooks in the page-building process (e.g., functionality previously available through packages such as atbegshi or atveryend and a few others).
The important point here is not so much that the functionality of these packages has been integrated into the LaTeX kernel, but that the hook management system provides a single structured way for different packages to reliably add and order code. This will resolve many of the inter-package interoperability issues which formerly could be resolved (if at all) only by loading the packages in a specific order, or by the use of complex and fragile code inside the packages to account for various scenarios in user documents.
The hook management system is currently described in these three documents:
• texdoc lthooks — The description of the interfaces and the core hooks already added to the kernel.
• texdoc ltshipout — The documentation of the hooks available during the page production process.
• texdoc ltfilehook — hooks that can be used before or after a file gets loaded.
### Providing xparse as part of the format
In the previous release we added the LaTeX3 programming layer to the LaTeX format to improve the loading speed when packages using expl3 are used. In this release we are now extending this support by integrating xparse so that the extended interface for defining document-level commands becomes available out of the box.
This enables users and most importantly package developers to easily define LaTeX commands with multiple optional arguments or other syntax features with ease. For details, check out the xparse documentation, e.g., via texdoc xparse.
### Improving the font series handling
In the previous release we extended NFSS (the new font selection scheme) to better support modern fonts that offer different font faces, e.g., condensed, semi-bold, etc., and make them work seamlessly with each other. Experiences with the extended interface showed that for some use cases adequate support was still missing or that in special setups the algorithms sometimes selected a wrong font series value. These cases have now been resolved and additional support commands have been added. For example, with
\IfFontSeriesContextTF{〈context〉} {〈true code〉}{〈false code〉}
you can now define commands that behave differently depending on the current font series context. The 〈context〉 to check has to be specified as either bf or md. The command then chooses the 〈true code〉 or the 〈false code〉 based on where it is used (e.g., inside \textbf (or \bfseries) or not).
### A large number of other enhancements and corrections
There are nearly fifty other enhancements and corrections that we documented in the ltnews article for this release (and a few very minor ones that only made it into the changes.txtfile) The most important ones from a user perspective are:
• Support for length expression in coordinates of picture commands as an alternative to decimal numbers denoting a multiple of \unitlength, e.g., \put(0,.2\textheight){...}
• New commands to make copies of robust commands (\let wouldn’t work for them)
• A new \ShowCommand command to display the full definition of a robust command (works also on other commands)
But read the whole ltnews article because there may be other gems that are useful for you.
The new features and most the important bug fixes made in this release are documented in “LaTeX2e News Issue 32”. This document can be found on the LaTeX2e news page where you will also find release information for earlier LaTeX releases.
Happy LaTeXing — Frank
## 2020-09-27
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
Vermutlich ist es nicht so bekannt, dass man LaTeX-Pakete auch per REST-API auf CTAN hochladen kann. Das ist insbesondere dann praktisch, wenn man öfter Pakete aktualisieren muss, wie ich es beispielsweise mit der DTK Bibliografie mehrmals im Jahr mache.
Manfred Lotz vom CTAN-Team hat dazu ein Python-Skript geschrieben (https://gitlab.com/Lotz/pkgcheck/blob/master/ctan_upload.py), das diese API befüttert.
Ich habe sein Skript noch ein wenig angepasst (ich erstelle auch die ZIP-Datei damit und kopiere die richtigen Dateien an ihren Platz), mein Skript findet ihr im Github unter https://github.com/dante-ev/dtk-bibliography/blob/master/pack_and_upload_to_ctan.py. Für den Upload selbst benötigt man noch eine TOML-Datei, in der die Upload-Informationen als Key-Value-Paare stehen. Ein Beispiel für eine solche TOML-Datei findet ihr bei Manfred unter https://gitlab.com/Lotz/pkgcheck/-/blob/master/pkgcheck.toml.
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2020-09-22
### TUG
#### TUGboat 41:2 published
TUGboat volume 41, number 2, the TUG 2020 (online) proceedings, has been mailed to TUG members. It is also available online and from the TUG store. In addition, prior TUGboat issue 41:1 is now publicly available. Submissions for the next issue are welcome; the deadline is October 15. Please consider joining or renewing your TUG membership if you haven't already (you'll get this issue immediately), and thanks.
# Talks from the online TUG Conference 2020 are now available on YouTube
The first TUG online conference in July was quite a success with many interesting talks on many subjects of TeX usage and related topics. The talks are now appearing one after another on YouTube, thanks to the work of a few individuals who have prepared them (and the question/answer sessions) for publication.
If you have missed the conference (or if you want listen to one of the talks again) you will find them on the TeX Users Group Channel on YouTube. So far only a subset of the talks have been added; the remaining ones will probably appear pretty soon.
There are also several talks by members of the LaTeX Project team. These are:
Enjoy — Frank
# The third and final LaTeX pre-release for 2020-10-01 is available for testing
A few days ago we submitted a new LaTeX development format1 to CTAN and by now this should be available to all users using MiKTeX or TeX Live (on any operating system).
## Main features of the final pre-release for 2020-10-01
In the previous pre-releases, distributed in May and July, the following main features (besides bug fixes) were made available:
• The functionality of the xparse package was added directly to the LaTeX kernel.
• LaTeX’s font series handling was improved.
• A general hook management system was added to improve package interoperability and enable easier customization.
In this final prerelease we have fully integrated the hook management system (previously it was added at the end, overwriting earlier definitions in the kernel). In addition the following features were added:
• The picture environent now supports dimensions (and not only numbers multiplied by \unitlength) in places where coordinates have to be specified. This is basically incorporating into the kernel the functionality of the picture.sty package by Heiko Oberdiek.
• A \ShowCommand was added to show the definition of robust commands in an easy manner.
• A \NewCommandCopy was added to allow making copies of robust commands (which can’t be done using \let).
• docstrip and l3docstrip were merged so that one can now always use docstrip even with expl3-based sources.
### Other fixes and improvements
There have been a larger number of smaller bug fixes and enhancements. A full list of all fixes and additions is given in a draft version of ltnews32, which you should be able to read by running
texdoc ltnews32
on the command line (or by any other means available with your operating system—somewhere there should be a file called ltnews32.pdf that you can open with a PDF reader). The draft version of this file is also available from our website as LaTeX2e News Issue 32 draft.
### A general hook management system for LaTeX (the main feature of the 2020 fall release)
Most LaTeX users and package writers will know the handful of hooks that LaTeX has been offering until now, the most important one perhaps being \AtBeginDocument. These are important hooks, but they are far too few so that in many cases package developers had to directly patch the internals of LaTeX. This resulted in many problems.
With the new hook management system, LaTeX will get many more hooks that packages writers (and authors) can use to add code in a controlled and reliable way. New hooks have been added in a number of places by using the new system and more will follow over time. Available now are:
• Hooks to add code before and after environments (formerly offered through the etoolbox package);
• Hooks used when loading files, packages, or classes (similar to what the filehook package now provides);
• Hooks in the page-building process (e.g., functionality previously available through packages such as atbegshi or atveryend and a few others).
The important point here is not so much that the functionality of these packages has been integrated into the LaTeX kernel, but that the hook management system provides a single structured way for different packages to reliably add and order code. This will resolve many of the inter-package interoperability issues which formerly could be resolved (if at all) only by loading the packages in a specific order, or by the use of complex and fragile code inside the packages to account for various scenarios in user documents.
The hook management system is currently described in these three documents:
• texdoc lthooks — The description of the interfaces and the core hooks already added to the kernel.
• texdoc ltshipout — The documentation of the hooks available during the page production process.
• texdoc ltfilehook — hooks that can be used before or after a file gets loaded.
## Outlook
We expect this to be the final pre-release matching the code that goes into the 2020-10-01 release, except for any bug fixes that are found between now and the release date.
We are issuing this final pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.
This development format allows you to test the upcoming LaTeX release scheduled for 2020-10-01 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.
Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release hits the streets.
Processing your documents with the pre-release is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
Enjoy — Frank
1. The internal version number for this pre-release is LaTeX2e <2020-10-01> pre-release-8, the first 5 pre-releases just mirrored the patch releases we did for 2020-02-02.
## 2020-08-30
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Mailman Spammer mit Python blocken
Für Dante e.V. betreue ich einige E-Mail-Listen auf mailman-Basis, die seit einigen Tagen von Spammern geflutet werden. Jeden Tag sind dutzende bis hunderte Aufnahme-Requests in der Liste, die ich manuell wegwerfen müsste. Nachdem ich dies einmal händisch getan hatte, musste eine automatische Lösung gefunden werden.
Die Lösung bestand darin, einen Treiber für Firefox („geckodriver“) zu installieren, der das Fernsteuern des Browsers erlaubt. Dann kann mittels selenium Modul die Steuerung aus Python heraus erfolgen. Unten der wesentliche Quellcode als Basis für eigene Arbeiten, den Teil zum Erkennen von legitimen Anfragen habe ich weggelassen.
Nachtrag vom 25.10.2020: Siehe auch die Erweiterung unter https://www.uweziegenhagen.de/?p=4420
# -*- coding: utf-8 -*-
"""
"""
from selenium.webdriver import Firefox
from selenium.webdriver.firefox.options import Options
opts = Options()
#opts.set_headless() # Ich will sehen, wie selenium arbeitet
browser.implicitly_wait(3)
# einloggen
browser.get('<url panels')="" mailman="" search_form="browser.find_element_by_name('<passwortfeld_ID" admin="" des="">')
search_form.submit()
#wegwerfen Button pro Zeile
fields = browser.find_elements_by_xpath("//input[@value='3']")
emails = browser.find_elements_by_xpath('//td[contains(text(),"@")]')
if len(fields) == len(emails):
zipped_list = list(zip(emails, fields))
for i in zipped_list:
email, field = i
field.click()
</adminpasswort></url>
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
# The second LaTeX pre-release for 2020-10-01 is available for testing
A few days ago we submitted a new LaTeX development format1 to CTAN and by now this should be available to all users using MiKTeX or TeX Live (on any operating system).
## Main features of the second pre-release for 2020-10-01
The first pre-release, distributed at the end of May, had the following two main features (beside bug fixes):
• the functionality of the xparse package was added directly to the LaTeX kernel
• LaTeX’s font series handling was improved
This second pre-release adds one major new component to LaTeX: a general hook management system to improve package interoperability and enable easier customization and extension of LaTeX.
### A general hook management system for LaTeX
Most LaTeX users and package writers will know the handful of hooks that LaTeX has been offering until now, the most important one perhaps being \AtBeginDocument. These are important hooks, but they are far too few so that in many cases package developers had to directly patch the internals of LaTeX. Thus resulted in many problems.
With the new hook management system, LaTeX will get many more hooks that package writers (and authors) can use to add code in a controlled and reliable way. New hooks have been added in a number of places by using the new system and more will follow over time. Available now are:
• Hooks to add code before and after environments (formerly offered through the etoolbox package);
• Hooks used when loading files, packages, or classes (similar to what the filehook package now provides);
• Hooks in the page-building process (e.g., functionality previously available through packages such as atbegshi or atveryend and a few others).
The important point here is not so much that the functionality of these packages has been integrated into the LaTeX kernel, but that the hook management system provides a single structured way for different packages to reliably add and order code. This will resolve many of the inter-package interoperability issues which formerly could be resolved (if at all) only by loading the packages in a specific order, or by the use of complex and fragile code inside the packages to account for various scenarios in user documents.
The hook management system is currently described in these three documents (for the final release they will be consolidated):
• texdoc lthooks — The description of the interfaces and the core hooks already added to the kernel.
• texdoc ltshipout — The documentation of the hooks available during the page production process.
• texdoc ltfilehook — hooks that can be used before or after a file gets loaded.
### Other fixes and improvements
A full list of all fixes and additions is given in a draft version of ltnews32 which you should be able to read by running
texdoc ltnews32
on the command line (or by any other means available at your operating system—somewhere there should be a file called ltnews32.pdf that you can open with a PDF reader). The draft version of this file is also available from our website as LaTeX2e News Issue 32 draft.
## Outlook
We expect to produce a third and final pre-release incorporating the user feedback we receive and consolidating some of the documentation. A few additional outstanding issues are expected to get fixed as well, but nothing major — the main functionality planned for the fall release is available already now with the second pre-release.
We are issuing this second pre-release now in the hope that you will help us by making sure that all the enhancements and fixes we have provided are safe and that they do not have any undesired side effects, so please help with the testing if you can.
This development format allows you to test the upcoming LaTeX release scheduled for 2020-10-01 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problems beforehand but such an undertaking is necessarily incomplete, which is why we are asking for user testing.
Besides developers, we also ask ordinary users to try out the new release, because the more people that test the new format, the higher the chances that any hidden problems are identified before the final release in October hits the streets.
Processing your documents with the pre-release is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
Enjoy — Frank
1. The internal version number for the pre-release is LaTeX2e <2020-10-01> pre-release-7, the first 5 pre-releases just mirrored the patch releases we did for 2020-02-02.
# New articles by project members
We have added five articles recently published in TUGboat to the site.
• Enrico discusses aspects of mathematical typesetting,
• Frank’s article discusses a new package that implements an improved algorithm for float handling,
• Joseph looks a case changing in the Unicode world and the LaTeX3 tools available,
• Ulrike’s article gives a sort overview about the work going on in providing tagged PDF documents and
• Ulrike and Marcel discuss the use of LuaLaTeX with Harfbuzz in a case study.
You will find all of them on the Publications from 2020 page.
## 2020-07-19
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Appendixnotes für Beamer-Präsentationen
Remark: An English version of this article has been published on latex.net.
Stellen wir uns vor, dass wir in einer Präsentation eine Abschlussarbeit verteidigen müssen. Es kann sein, dass weitergehende Fragen kommen, die dann tiefergehend beantwortet werden müssen.
Wir könnten das entsprechende Material direkt in die Präsentation setzen, müssen dann beim Vortrag aber eventuell Folien überspringen, was auch kein guter Präsentationsstil ist. Die zusätzlichen Inhalte einfach nur ans Ende setzen ist auch schlecht, im schlimmsten Fall muss man dann während der Präsentation hin- und herspringen.
Eine elegante Lösung gibt es mit dem beamerappendixnote Paket. Es nutzt zwei Befehle, \appxnote und \printappxnotes, um Material für den Anhang zu integrieren.
Der erste Befehl erstellt den Link zum Anhang und den anzuzeigenden Link-Text, der zweite Befehl setzt alle Appendix-Notizen.
\documentclass[12pt,ngerman]{beamer}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage{beamerappendixnote}
\begin{document}
\begin{frame}
\frametitle{Some Beamer Slide}
\begin{itemize}
\item Some stuff
\item that requires
\item more background
\end{itemize}
\appxnote{Proof}{We can easily prove this.}
\end{frame}
\printappxnotes
\end{document}
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
### LaTeX.net
#### Sorting Glossaries with bib2gls
In previous posts I discussed the glossaries package (which can be extended with the glossaries-extra package) and also using makeindex or xindy to sort the terms that had been indexed in the document. This post describes another tool, bib2gls, which can be used instead of makeindex or xindy.
Makeindex and xindy are both general purpose indexing applications, but bib2gls was designed specifically for use with glossaries-extra and works in a very different way. With makeindex and xindy, commands like \gls add indexing information to an external file. This information consists of the sort value, hierarchical information (if the term has a parent entry), the associated formatting code to display the entry in the glossary and the location (normally the page number) where the indexing occurred. The indexing application sorts and collates this information and writes all the code needed to format the glossary in another file, which is input by \printglossary.
By contrast, bib2gls doesn’t create a file containing the code to typeset the glossary. Instead, it parses bib files containing definitions of terms, symbols and abbreviations, then selects the entries that are required by the document and writes the LaTeX code (using commands provided by glossaries-extra.sty) that defines these terms in a file that’s input by the preamble-only command \GlsXtrLoadResources. All the indexing information (such as the locations) is stored in internal fields associated with each entry. If a glossary is required, it can be displayed with \printunsrtglossary (or \printunsrtglossaries, which does \printunsrtglossary for each defined glossary).
This means that you can have a large database of all entries defined in a bib file (or across multiple bib files) that can be managed in an application such as jabref. If you have a document that only requires, say, 10 from a database of 1000 entries, then LaTeX only needs to use the resources required to define those 10 entries, which can improve the document build time.
## \printunsrtglossary
The \printunsrtglossaries command was briefly mentioned in an earlier post. When using bib2gls it helps to understand how \printunsrtglossary works. The “unsrt� part of the name stands for “unsorted� because this command simply iterates over all defined entries in the order in which they were defined. There is no attempt to sort entries or gather child entries, although letter group headings are inserted whenever a change in group is detected. As was previously illustrated, this can cause strange results. Consider the following example:
\documentclass{article}
\usepackage[style=indexgroup]{glossaries-extra}
\newglossaryentry{parrot}{name={parrot},
description={mainly tropical bird with bright plumage}
}
description={nocturnal insectivore with large claws}
}
\newglossaryentry{zebra}{name={zebra},
description={wild African horse with black-and-white stripes}
}
\newglossaryentry{duck}{name={duck},
description={a waterbird with webbed feet}
}
\newglossaryentry{aardvark}{name={aardvark},
description={nocturnal African burrowing mammal}
}
\newglossaryentry{macaw}{name={macaw},
parent={parrot},
description={long-tailed, colourful parrot}
}
\newglossaryentry{mallard}{name={mallard},
parent={duck},
description={dabbling duck with long body and broad bill}
}
\newglossaryentry{ara}{name={Ara},
parent={macaw},
description={neotropical genus of macaw}
}
\newglossaryentry{northernpintail}{name={northern pintail},
parent={duck},
description={long-necked, small-headed duck with curved back}
}
\newglossaryentry{anodorhynchus}{name={Anodorhynchus},
parent={macaw},
description={genus of large blue macaws}
}
\begin{document}
\printunsrtglossary
\end{document}
This produces a strange result (click to view larger version).
The list is in the order of definition. The parent key simply provides the hierarchical level for the benefit of the glossary style. The level starts at 0 for top-level (parentless) entries, then 1 for an entry that has a parent but no grandparent, 2 for an entry with a grandparent but no great-grandparent, etc. The glossary style may (or may not) apply a different format for entries according to their hierarchical level. In the case of the indexgroup style used here, different indenting is applied. In this example, this has led to a rather strange visual appearance that makes it look as though “macaw�, “mallard� and “northern pintail� are sub-items of “aardvark�, and the macaw genera appear to be sub-items of “mallard� and “northern pintail�.
The default behaviour of bib2gls is to hierarchically sort all the required entries before writing them to the file that’s input by \GlsXtrLoadResources. This means that \printunsrtglossary should then list them in an appropriate order.
While \printunsrtglossary iterates over all the entries for the given glossary, it inserts the group headers as follows:
1. If the current entry doesn’t have a parent, then:
1. find the group label associated with the current entry
2. if the group label is different to the previous group label then:
1. if there’s no previous group label just insert \glsgroupheading{label}
2. if there is a previous group label insert \glsgroupskip\glsgroupheading{label}
The way the group label is obtained depends on the glossaries-extra package options and on bib2gls settings. Whether or not the group heading is actually displayed depends on the glossary style. Some styles simply redefine \glsgroupheading to do nothing (but \glsgroupskip may still create a vertical space).
## Switching to bib2gls
Let’s rewrite the above example so that it uses bib2gls. The first thing that needs to be done is to create a bib file that contains all the entry definitions. If you already have an existing .tex file that contains all your entries then bib2gls comes with a convenient command-line application called convertgls2bib, which can parse a .tex file for commands like \newglossaryentry and \newabbreviation and create a bib file suitable for use with bib2gls. For example, if the above document is contained in the file myDoc.tex then run the following from a command prompt:
convertgls2bib -p myDoc.tex entries.bib
(The -p switch indicates that convertgls2bib should only parse the document preamble.) This will create the file entries.bib that contains the following:
% Encoding: UTF-8
@entry{parrot,
name = {parrot},
description = {mainly tropical bird with bright plumage}
}
description = {nocturnal insectivore with large claws}
}
@entry{zebra,
name = {zebra},
description = {wild African horse with black-and-white stripes}
}
@entry{duck,
name = {duck},
description = {a waterbird with webbed feet}
}
@entry{aardvark,
name = {aardvark},
description = {nocturnal African burrowing mammal}
}
@entry{macaw,
parent = {parrot},
name = {macaw},
description = {long-tailed, colourful parrot}
}
@entry{mallard,
parent = {duck},
name = {mallard},
description = {dabbling duck with long body and broad bill}
}
@entry{ara,
parent = {macaw},
name = {Ara},
description = {neotropical genus of macaw}
}
@entry{northernpintail,
parent = {duck},
name = {northern pintail},
description = {long-necked, small-headed duck with curved back}
}
@entry{anodorhynchus,
parent = {macaw},
name = {Anodorhynchus},
description = {genus of large blue macaws}
}
The definitions now need to be removed from myDoc.tex and the record package option is required. The stylemods option is also useful (but not essential). This will load the glossaries-extra-stylemods package, which modifies the predefined styles provided by glossaries.sty to make them easier to adjust and also to make them integrate better with bib2gls.
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
The \GlsXtrLoadResources command is also required. This writes information to the aux file for the benefit of bib2gls as well as inputting the file created by bib2gls (if it exists). By default, bib2gls will only select entries that have been indexed in the document (using commands like \gls) and any dependent entries. In this example, I want to select all entries that have been defined in my entries.bib file, which means I need to use the selection=all option.
\GlsXtrLoadResources[src=entries,selection=all]
The src option indicates the name or names of the bib files where the entry data is defined. In this case, there’s only one file. If I have additional files, they need to be specified in a comma-separated list. Note that this means that braces will be required to prevent the comma from being parsed as part of the key=value list. For example, if I also have entries in the file abbreviations.bib, then I would need:
\GlsXtrLoadResources[src={entries,abbreviations},selection=all]
The complete document is now:
\documentclass{article}
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
\begin{document}
\printunsrtglossary
\end{document}
The document build process is similar to using makeglossaries, but bib2gls is used instead:
pdflatex myDoc
bib2gls myDoc
pdflatex myDoc
(Alternatively, use xelatex etc instead of pdflatex.) This produces the glossary shown below:
The ordering is now correct: aardvark, armadillo, duck (with sub-entries mallard and northern pintail), parrot (with sub-entry macaw that has sub-entries Anadorhynchus and Ara) and zebra. However, there are no letter group headings, even though the indexgroup style has been used. This is because bib2gls doesn’t set the group labels by default (not all glossaries require them). If you need the glossary separated into letter groups then you should instruct bib2gls to set the group labels using the --group (or -g) switch:
pdflatex myDoc
bib2gls --group myDoc
pdflatex myDoc
If you are using arara you need to add the following lines to your document:
arara: pdflatex
arara: bib2gls: { group: on }
arara: pdflatex
(For other ways of integrating bib2gls into your document build see Incorporating makeglossaries or makeglossaries-lite or bib2gls into the document build.) With the --group switch, the glossary now looks like:
Naturally you also need to use a glossary style that supports groups.
If the document source is in the file myDoc.tex then bib2gls will create a file called myDoc.glstex that corresponds to the first \GlsXtrLoadResources command. If there are multiple instances of this command then myDoc-1.glstex will correspond to the second \GlsXtrLoadResources, myDoc-2.glstex will correspond to the third \GlsXtrLoadResources etc. These files simply contain LaTeX code and so can be inspected in a text editor.
In order to make it easier to perform minor adjustments, the glstex files provide wrapper commands. For example, terms that are defined with @entry in the bib file are defined in the glstex file using \bibglsnewentry, which has the definition provided before the first instance of its use:
\providecommand{\bibglsnewentry}[4]{%
\longnewglossaryentry*{#1}{name={#3},#2}{#4}%
}
This uses \longnewglossaryentry* instead of \newglossaryentry to allow for paragraph breaks in the description. If you try the above example document and look at the glstex file, you will see the entry definitions. These include the sort key for informational purposes. If you’re not sure why bib2gls ordered the entries a certain way, checking the sort key in the glstex file can show you the value used by the selected bib2gls sort method. For example, the “northern pintail� entry is defined in the glstex file as follows:
\bibglsnewentry{northernpintail}%
{parent={duck},
sort={northern|pintail|}}%
{northern pintail}%
{long-necked, small-headed duck with curved back}
Note that the sort value is northern|pintail| because the default sort method is a locale-sensitive word sort that discards spaces and (some) punctuation and marks up the end of each word with a marker (the pipe character | by default). Any remaining non-letter characters may by ignored by the comparison function (the comparator). This is appropriate for entries where the name is a word or phrase but may not be appropriate for other types of entries, such as symbols.
## Sort Fallbacks
In general, you typically shouldn’t set the sort field in the bib file, but instead use bib2gls’s fallback system to choose the most appropriate field. If the sort field is explicitly set then the fallback isn’t used. The fallback depends on the entry type used in the bib file. For example, if a term was defined in the bib file using @entry then the sort fallback is obtained from the name field. However, if the term was defined using @symbol (or @number) then the sort fallback is obtained from the label, and if the term was defined using @abbreviation (or @acronym) then the sort fallback is obtained from the short field
Suppose now that in addition to my entries.bib file described above, I also have a file called abbreviations.bib that contains:
% Encoding: UTF-8
@abbreviation{xml,
short={XML},
long={extensible markup language},
description={a markup language that defines a set of rules for
encoding documents}
}
@abbreviation{html,
short={HTML},
long={hypertext markup language},
description={the standard markup language for creating web pages}
}
and a file called constants.bib that contains:
% Encoding: UTF-8
@number{pi,
description={ratio of circumference of a circle to its diameter},
name={\ensuremath{\pi}},
user1={3.14159}
}
@number{e,
description={Euler's number},
name={\ensuremath{e}},
user1={2.71828}
}
@number{root2,
description={Pythagoras' constant},
name={\ensuremath{\surd2}},
user1={1.41421}
}
@number{gelfondscons,
description={Gelfond's constant},
name={\ensuremath{e^\pi}},
user1={23.140692}
}
@number{zero,
description={zero},
name={\ensuremath{0}}
}
@number{one,
description={one},
name={\ensuremath{1}}
}
I can now modify my document as follows:
\documentclass{article}
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
\setabbreviationstyle{long-short-desc}
\begin{document}
\printunsrtglossaries
\end{document}
Note that I have to set the abbreviation style before \GlsXtrLoadResources. This produces the following glossary:The sort value for the mathematical constants has been obtained from the label. For example, Pythagoras’ constant has the label root2 and so ends up in the “R� letter group, whereas π (which has the label pi) is in the “P� letter group. The sort value for the extensible markup language (XML) term has been obtained from the short field (XML) so it ends up in the “X� letter group. The fallback values can be changed. For example:
\documentclass{article}
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
\setabbreviationstyle{long-short-desc}
abbreviation-sort-fallback=long,
symbol-sort-fallback=description,
selection=all]
\begin{document}
\printunsrtglossaries
\end{document}
This will now use the long field as the fallback for abbreviations (@abbreviation or @acronym) and the description field as the fallback for symbols (@symbol or @number).The “extensible markup language (XML)� entry is now in the “E� letter group and Pythagoras’ constant is now in the “P� letter group, but π (pi) is now in the “R� letter group.
## Sub-Blocks
I’m now going to make a strange modification to the above document:
\documentclass{article}
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
\setabbreviationstyle{long-short-desc}
sort={en-reverse},
symbol-sort-fallback=description,
selection=all]
abbreviation-sort-fallback=long,
selection=all]
\begin{document}
\printunsrtglossary
\end{document}
This splits the data in the three bib files into three separate resource commands (\GlsXtrLoadResources).
The first \GlsXtrLoadResources selects all the terms defined in entries.bib and sorts them according to my locale (since there’s no language set in the document) which happens to be en-GB (British English). These terms are written to the myDoc.glstex file, which is input by the first resource command on the next LaTeX run.
The second command selects all the terms defined in constants.bib and sorts them according to en-reverse (reverse English, that is, Z–A) and writes them to myDoc-1.glstex, which is input by the second resource command.
The third command selects all the terms defined in abbreviations.bib and sorts them according to my locale and writes them to myDoc-2.glstex, which is input by the third resource command.
Remember that \printunsrtglossary simply iterates over all entries in the order in which they are defined (via commands like \longnewglossaryentry or \newabbreviation, not the order in which they are defined in the bib files). This results in the order: (first glstex file) aardvark and armadillo (both assigned to the “A� letter group), duck (assigned to the “D� letter group) followed by its child entries, parrot (assigned to the “P� letter group) followed by its descendants, zebra (assigned to the “Z� letter group) then (second glstex file) zero (assigned to the “Z� letter group), π (assigned to the “R� letter group), Pythagoras’ constant (assigned to the “P� letter group), one (assigned to the “O� letter group), Gelfond’s constant (assigned to the “G� letter group), and Euler’s number (assigned to the “E� letter group) then (third glstex file) extensible markup language (assigned to the “E� letter group) and hypertext markup language (assigned to the “H� letter group).
Note that there’s no visual indication between the sub-blocks. The “Z� letter group contains zebra from the end of the first sub-block and zero from the start of the second sub-block. The “E� letter group contains Euler’s number from the end of the second sub-block and extensible markup language from the start of the third sub-block. Note also that there are two “P� letter groups: one from the first sub-block and the other from the second.
This is a contrived example. It’s more typical to use multiple resource commands to process multiple glossaries that require different settings or to gather together all entries in a sub-block into a custom group. (See also Logical Glossary Divisions (type vs group vs parent).)
The following modification demonstrates custom groups:
\documentclass{article}
\usepackage[record,stylemods,style=indexgroup]{glossaries-extra}
\setabbreviationstyle{long-short-desc}
\glsxtrsetgrouptitle{cons}{Mathematical Constants}
group=cons,% group label
symbol-sort-fallback=description,
selection=all]
\glsxtrsetgrouptitle{abbrvs}{Abbreviations}
group=abbrvs,% group label
abbreviation-sort-fallback=long,
selection=all]
\begin{document}
\printunsrtglossary
\end{document}
This assigns the constants to a group labelled cons with the title “Mathematical Constants� and assigns the abbreviations to a group labelled abbrvs with the title “Abbreviations�.
## Multiple Glossaries
The following demonstrates multiple glossaries:
\documentclass{article}
\usepackage[abbreviations,symbols,record,stylemods=mcols]{glossaries-extra}
\setabbreviationstyle{long-short-desc}
type=symbols,
symbol-sort-fallback=description,
selection=all]
type=abbreviations,
abbreviation-sort-fallback=long,
selection=all]
\begin{document}
\printunsrtglossary[style=indexgroup]
\printunsrtglossary[type=symbols,style=mcolindex,nogroupskip]
\printunsrtglossary[type=abbreviations,style=index]
\end{document}
This uses the abbreviations and symbols package options to create the additional glossaries. Note that the use of multiple glossaries means that I can apply a different style to each glossary. (The stylemods=mcols option indicates to load glossary-mcols.sty as well as loading glossaries-extra-stylemods.sty.) The mcolindex style doesn’t display the group headings but it does still create a vertical gap with \glsgroupskip. I’ve added the nogroupskip option to suppress it. The index style likewise doesn’t show the group heading but does create a vertical gap. I haven’t used the nogroupskip option for the abbreviations glossary so the inter-group gap is visible.
The type=abbreviations resource option wasn’t actually necessary in the above example. Entries defined in the bib file with @abbreviation are written to the glstex file using the provided command:
\providecommand{\bibglsnewabbreviation}[4]{%
\newabbreviation[#2]{#1}{#3}{#4}%
}
Note that this uses \newabbreviation which automatically assigns the entry to the “abbreviations� glossary if the abbreviations package option is used. This means that both the main glossary and the abbreviations can be processed in one resource command:
\GlsXtrLoadResources[
src={entries,abbreviations},
abbreviation-sort-fallback=long,
selection=all]
This only needs to be split into two resource commands if there are conflicting settings. For example, suppose I want bib2gls to ignore the description fields in the abbreviations.bib file but not the entries.bib file. Then I would need:
\GlsXtrLoadResources[src={entries},selection=all]
\setabbreviationstyle{long-short}
ignore-fields={description},
selection=all]
## Categories
In an earlier post I mentioned categories, which can be assigned using the category key. It’s possible to assign this key using the resource command with the same name. For example, I could make all my entries in the constants.bib file have the category “symbol� like this:
\GlsXtrLoadResources[src={constants},
type=symbols,
category=symbol,
symbol-sort-fallback=description,
selection=all]
Alternatively I could use category={same as entry}, which would make the category the same as the bib entry type without the leading @ (in this case number), or category={same as type}, which would make the category the same as the type (in this case symbols), or category={same as base}, which would make the category the same as the basename of the bib file without the .bib extension (in this case constants).
The other post described how to define a post-link category hook using \glsdefpostlink. This allows additional content to be added after commands like \gls for a particular category. There’s a similar hook that’s implemented after the description is displayed with the standard glossary styles.
\glsdefpostdesc{category}{definition}
This is something you can also use with makeindex and xindy, but the bib2gls resource options make it easier to change the category for specific documents without having to alter the entry definition.
Some of the terms defined in constants.bib have the user1 field set to the approximate numerical value. Assigning a category and post-description hook makes it easy to display this value in the glossary. Note that the post-description hook comes before the punctuation inserted with the postdot or postpunc package options.
\documentclass{article}
\usepackage[postdot,abbreviations,symbols,record,stylemods={mcols}]{glossaries-extra}
\glsdefpostdesc{number}{%
\glsxtrifhasfield{useri}{\glscurrententrylabel}%
{\space ($\approx\glscurrentfieldvalue$)}{}%
}
type=symbols,
category={same as entry},
symbol-sort-fallback=description,
selection=all]
\setabbreviationstyle{long-short}
ignore-fields={description},
selection=all]
\begin{document}
\printunsrtglossary[style=indexgroup]
\printunsrtglossary[type=symbols,style=mcolindex,nogroupskip]
\printunsrtglossary[type=abbreviations,style=index]
\end{document}
For example, Euler’s number is now followed by “ (≈2.71828)�. The closing full stop (automatically inserted by the postdot package option) comes after the parenthetical material. Note that zero and one don’t have the user1 field set as the value given in the name field is the exact numerical value.
## Numeric Sorting
There are some numerical sorting methods available to use with bib2gls, such as sort=integer for integers or sort=double for double-precision floating point values. For locale-sensitive numbers (that include thousand separators) you need to use sort=numeric or sort=numberformat instead. Let’s suppose that I now want the mathematical constants ordered according to their approximate value. As before I can use symbol-sort-fallback to change the fallback field to user1, but that will leave a blank sort value for zero and one, which don’t have that field set.
With bib2gls version 2.7 or above, I can use the field concatenation operator symbol-sort-fallback=user1+name. This will construct the sort fallback value from a combination of the user1 value and the name. This means that, for example, Euler’s number will have the sort value 2.71828 \ensuremath{e} and “one� will have the sort value \ensuremath{1}. The non-numeric content can then be stripped off using:
sort-replace={{[^0-9\string\.\string\-]+}{}}
The following is a modification of the previous example document. I’ve decided to provide my own custom glossary for the mathematical constants instead of using the one provided by the symbols package option for illustrative purposes.
\documentclass{article}
\usepackage[postdot,abbreviations,record,stylemods={mcols}]{glossaries-extra}
\glsdefpostdesc{number}{%
\glsxtrifhasfield{useri}{\glscurrententrylabel}%
{\space ($\approx\glscurrentfieldvalue$)}{}%
}
\newglossary*{constants}{Mathematical Constants}
type=constants,
category={same as entry},
sort=double,
symbol-sort-fallback=user1+name,
sort-replace={{[^0-9\string\.\string\-]+}{}},
selection=all]
\setabbreviationstyle{long-short}
ignore-fields={description},
selection=all]
\begin{document}
\printunsrtglossary[style=indexgroup]
\printunsrtglossary[type=constants,style=mcolindex,nogroupskip]
\printunsrtglossary[type=abbreviations,style=index]
\end{document}
The list of mathematical constants is now ordered according to the associated numeric value: 0, 1, Pythagoras’ constant (1.41421), Euler’s number (2.71828), π (3.14159) and Gelfond’s constant (23.140692). Note that the main glossary and list of abbreviations are still ordered according to the locale-sensitive word sort method.
(If you decide to change the glossary label, you may need to delete the glstex files before you can rebuild the document.)
## The TeX Parser Library
When determining the sort value, bib2gls uses the TeX Parser Library if the value contains any of the following symbols: \ { } or $. This library isn’t a proper TeX engine and has to interpret TeX fragments outside of the complete document code, but it does understand a limited number of commands and is able to convert some common kernel symbol commands into the closest matching Unicode character. It also has some limited understanding of a few packages, such as siunitx, pifont and upgreek. To find the complete list run bib2gls from the command line with the --list-known-packages switch: bib2gls --list-known-packages If a command is unknown bib2gls will ignore it. This means that the sort value can end up empty if it originally consisted solely of unknown commands. Suppose now I want the mathematical constants from the previous example to be ordered according to the name (symbol-sort-fallback=name). When sorting symbols, it’s better to use a character code comparator rather than the locale-sensitive word method (which can discard non-letters). In the example document below I’ve used sort=letter-case, which is a case-sensitive character code sort method. \documentclass{article} \usepackage[postdot,abbreviations,record,stylemods={mcols}]{glossaries-extra} \GlsXtrLoadResources[src={entries},selection=all] \glsdefpostdesc{number}{% \glsxtrifhasfield{useri}{\glscurrententrylabel}% {\space ($\approx\glscurrentfieldvalue$)}{}% } \newglossary*{constants}{Mathematical Constants} \GlsXtrLoadResources[src={constants}, type=constants, category={same as entry}, sort=letter-case, symbol-sort-fallback=name, selection=all] \setabbreviationstyle{long-short} \GlsXtrLoadResources[src={abbreviations}, ignore-fields={description}, selection=all] \begin{document} \printunsrtglossary[style=indexgroup] \printunsrtglossary[type=constants,style=mcolindex,nogroupskip] \printunsrtglossary[type=abbreviations,style=index] \end{document} The main glossary and list of abbreviations are still ordered according to the locale-sensitive word sort but the list of mathematical constants is now ordered according to the character code of the interpreted sort value. The order is now: 0, 1, e (Euler’s number), eğ�œ‹ (Gelfond’s constant), √2 (Pythagoras’ constant) and ğ�œ‹ (pi). Note that ğ�œ‹ is the Unicode character Mathematical italic small pi U+1D70B (rather than the Greek lowercase Ï€ U+03C0). The square root symbol √ is the Unicode character U+221A, so √ comes before ğ�œ‹. ## @preamble As with bibtex, @preamble may be used in the bib file to provide commands that are used by one or more of the entries. The contents of @preamble are copied to the glstex file to ensure that the commands are defined in the document, but the contents are also supplied to the TeX parser library so that it can recognise those commands in the sort value, if required. The use of \providecommand to define the entries means that you can have an alternative definition in the document, but it must be defined before the glstex file is input. For example, suppose I have a file called books.bib that contains the following: @preamble{"\providecommand{\nameart}[2]{#2}"} @index{thehobbit, name={\nameart{The}{Hobbit}} } @index{ataleoftwocities, name={\nameart{A}{Tale of Two Cities}} } This provides the command \nameart which ignores its first argument and just does the second. This means that the TeX parser library will interpret \nameart{The}{Hobbit} as simply “Hobbitâ€�. A different definition can be provided in the document: \documentclass{article} \usepackage[record]{glossaries-extra} \newcommand{\nameart}[2]{#1 #2} \GlsXtrLoadResources[src=books,selection=all] \begin{document} \printunsrtglossary \end{document} This means that the articles “Aâ€� and “Theâ€� will be ignored when sorting. This results in the order: The Hobbit, A Tale of Two Cities because bib2gls only picks up the definition in @preamble not the one in the document. (@index is like @entry but doesn’t require a description. This can look a little odd when there’s no extra information, such as the location list.) The @preamble can also be used to supply alternative definitions for commands provided by packages in the document that bib2gls doesn’t recognise. Suppose, for example, that I need to use commands provided by marvosym, such as \Email. These commands aren’t recognised by the TeX parser library and so will be ignored if they occur in the sort value. The @preamble can be used to provide definitions that expand to the closest matching Unicode character. If \providecommand is used it won’t override the definition provided by marvosym. For example, I could create a file called pictographs.bib that contains: @preamble{"\providecommand{\Email}{\symbol{"1F584}} \providecommand{\Letter}{\symbol{"1F582}} \providecommand{\Mobilefone}{\symbol{"1F581}} \providecommand{\Telefon}{\symbol{"1F57F}}" } @symbol{email, name={\Email}, description={email} } @symbol{envelope, name={\Letter}, description={letter} } @symbol{phone, name={\Mobilefone}, description={mobile phone} } @symbol{landline, name={\Telefon}, description={telephone} } The document can then sort the name by character code: \documentclass{article} \usepackage{marvosym} \usepackage[record]{glossaries-extra} \GlsXtrLoadResources[src=pictographs, sort=letter-case, symbol-sort-fallback=name, selection=all ] \begin{document} \printunsrtglossary \end{document} The list is now in the order 🕿 (U+1F57F) telephone, ğŸ–� (U+1F581) mobile phone, 🖂 (U+1F582) letter, 🖄 (U+1F584) email. If there’s a possiblity that the contents of @preamble may cause a problem if they are copied into the glstex file, you can prevent the contents from being written using the write-preamble=false resource option. The contents will still be provided to the TeX parser library. If you want to prevent the contents from being interpreted use the interpret-preamble=false option. ## 2020-07-17 ### LaTeX Project #### Online TUG Conference 24-26 July 2020 # The first online TUG conference will happen 24-26 July 2020 You probably heard this already from other sources and maybe already registered, but if not, now is the time. Next week the annual TeX Users Group Conference will be broadcast live: to watch the presentations and otherwise participate all you need to do is to register. This year registration is free of charge, because the costs for an online event are much lower, so all that is needed to attend is the registration. A number of people from the LaTeX Project Team are giving presentations: Javier, Joseph, Marcel and myself. You will find many interesting and exciting talks in the program schedule and while some may be at inconvenient hours, depending on your location, most are probably at reasonable times. If not there are plans to make the talks available afterwards (no details yet), but live or partly live events are usually more fun in my opinion. So go ahead and register yourself if you are interested and let’s make this the biggest TeX conference in years! Enjoy — Frank ## 2020-07-14 ### LaTeX.net #### Managing beamer background materials with beamerappendixnote Imagine you are in a situation where you need to defend your thesis. Besides the actual presentation slides you have prepared lots of additional slides, just in case someone asks for the details of your proofs, etc. You could put them to the end of your presentation and manually jump there and back which I do clearly not recommend as it destroys the “natural flow” of your presentation. It is way better to use hyperlinks to get directly to the corresponding note and back. Until today I created these links manually, now I discovered a package named beamerappendixnote which automates these steps. Let’s have a look at the following example which loads the beamerappendixnote package. It uses two commands, \appxnote and \printappxnotes. The first creates the named link to the appendix and the text to be displayed, the latter command outputs all the appendixnotes. \documentclass[12pt,ngerman]{beamer} \usepackage[T1]{fontenc} \usepackage{babel} \usepackage{beamerappendixnote} \begin{document} \begin{frame} \frametitle{Some Beamer Slide} \begin{itemize} \item Some stuff \item that requires \item more background \end{itemize} \appxnote{Proof}{We can easily prove this.} \end{frame} \printappxnotes \end{document} ## 2020-07-10 ### LaTeX.net #### TUG 2020 program schedule online Great progress in a few days! Now there are 224 registered participants. And the program schedule with times and abstracts is online now: tug.org/tug2020/sched.html ## 2020-07-03 ### LaTeX.net #### TeX Users Group meeting 2020 online and for free This year’s annual TeX users conference will be held online via Zoom (an online meeting solution). This 41th TUG meeting will happen July 24-26, 2020, and registration and attendance is for free. No flight to pay, no hotel costs, no risk – check out the program! Until today, 166 participants registered, and 36 presentations are listed. Topics include • LaTeX online services (learnlatex.org, LaTeX-on-HTTP, Overleaf, texlive.info) • Tools (Make, Pandoc, Python) • Teaching LaTeX • Typography (conveying emotional charge in text, church material) • Fonts (Monotype, HarfBuzz, Malayalam, history) • Accessibility • Interviews (biber author, babel maintainer) and more, during sessions, workshops, keynotes, and connecting with users wordwide. The event contains video streams either live or prerecorded plus live discussion, and separate online rooms for “coffee talks”. For more information and attending, • read the program • visit the event site • write to [email protected] if you have a question The easiest way to attend a TUG meeting – see you there? ## 2020-06-29 ### LaTeX.net #### Protected: Cert This content is password protected. To view it please enter your password below: ## 2020-06-28 ### LaTeX.net #### Creating bilingual Beamer slides For a lecture on Python I have been looking for a way to create bilingual slides in a single document. Based on https://tex.stackexchange.com/questions/443714/bilingual-slides-beamer-comment-package-and-non-ascii-characters-umlauts-dia and https://tex.stackexchange.com/questions/203412/using-a-generic-way-to-evaluate-global-document-options I have compiled the following example. One simply needs to set the babel language in the document options to switch between German and English. \documentclass[ngerman]{beamer} \usepackage{comment} \makeatletter \newif\if@ngerman \newif\if@option@ngerman \DeclareOption{ngerman}{% \@ngermantrue \@option@ngermantrue } \ProcessOptions*\relax \newcommand*{\ifngerman}{% \if@ngerman \expandafter\@firstoftwo \else \expandafter\@secondoftwo \fi } \makeatother \ifngerman{ \usepackage[main=ngerman]{babel} \includecomment{DE} \excludecomment{EN} }{ \usepackage[main=english]{babel} \includecomment{EN} \excludecomment{DE} } \begin{document} \begin{DE} \begin{frame}[fragile]{Hallo Welt} Hallo Welt \end{frame} \end{DE} \begin{EN} \begin{frame}[fragile]{Hello World} Hello World \end{frame} \end{EN} \end{document} Photo by Alex Litvin on Unsplash #### Typesetting todo lists with fontawesome and the tasks package The following example shows, how todo lists and similar documents can be typeset with the tasks package, a spin-off of the exSheets package to generate task-like environments. In this example we define three tasks environments (for TODO, PROGRESSING, DONE), for each environment we use a different symbol from the fontawesome package, a collection of more than 600 logos, many of them related to internet and WWW. One could also use these packages to e.g. get entries from a Trello board, see the article in my blog (German): https://www.uweziegenhagen.de/?p=4228 \documentclass[12pt,english]{article} \usepackage[T1]{fontenc} \usepackage{babel} \usepackage{tasks} \usepackage{fontawesome} \NewTasksEnvironment[label=\faHandORight,label-width=15pt]{todo}[*](1) \NewTasksEnvironment[label=\faHandRockO,label-width=15pt]{progress}[*](1) \NewTasksEnvironment[label=\faThumbsOUp,label-width=15pt]{done}[*](1) \begin{document} \section*{TODO} \begin{todo} * Water the plants * Shop for groceries * Sort newspapers \end{todo} \section*{PROGRESSING} \begin{progress} * Clean the basement * Sort \LaTeX\ books * Reinstall Linux server \end{progress} \section*{DONE} \begin{done} * Finish tax declaration * Reinstall Windows server * Reconfigure SSH access \end{done} \end{document} ## 2020-06-27 ### LaTeX.net #### A Beamer Template for MINT Lectures As a lecturer for MINT lectures I wanted to create a Beamer template where individual lectures could be compiled separately as well as in a collection of all slides. After polishing the template for a few semesters an initial version of the template has been uploaded to Github (https://github.com/UweZiegenhagen/MINT-Lecture-Slide-Template). Feel free to send pull requests, comments and proposals. ## 2020-06-22 ### Reden ist Silber ¶ Druckerey Blog (Martin Z. Schröder, Drucker) #### Pedaltiegel mit Schwungrad zu verkaufen Er hat mir seit 2004 treu gedient. Briefpapier, Eheurkunden, Einladungen, kleine Plakate und das zweite der bibliophilen Büchlein von Max Goldt sowie die Umschläge der Bände 2 bis 4 wurden auf dieser Maschine gedruckt. Aber nun steht sie seit Jahren still. Wird nur noch alle paar Monate der Pflege-Routine unterzogen, entstaubt, ein wenig geölt und gestreichelt. Es wird Zeit, daß der Nußknacker einen neuen Rumpelkutscher findet. Gebaut wurde diese Maschine um 1900 von der Maschinenfabrik »Emil Kahle« in Leipzig-Paunsdorf. Ich habe sie in einem nicht verwendbaren Zustand aus einem Privatmuseum gekauft, woraus sie aus Platzmangel weichen mußte. Zu dritt hievten wir sie mit Mühe auf einem Transporter. In Berlin legten wir einen dicken Strick um die vor dem Haus Schonensche Straße 38 stehende Laterne und ließen das Fundament langsam auf einer Schräge aus Brettern ins Souterrain. Anno 2003 hatte ich diese Werkstatt erst bezogen. Wir bekamen sie aber nicht aufgestellt. Die Maschine lag schwer auf dem Boden und ließ sich von uns dreien nicht aufrichten. Da rief ich eine Freundin an und bat sie, mir ihren Sohn mit ein paar von dessen Freunden zu leihen. Dieser Sohn war nämlich damals ein junger Polizist und Kampfsportler. Er kam rasch mit seinen Freunden nach dem Fußballtrainig vorbei, und drei der überbreiten Herren stellten die Maschine spielerisch auf die Füße. Anschließend mußten einige Teile neu gedreht werden. Damals noch ohne CNC-Fräsen. Und ich mußte erst einmal eine Zeichnung der Walzenspindeln und Laufräder anfertigen. Ein Schlosser nahm sich der Sache an. Und der Tischlermeister Horst Wrede aus Emmen baute die fehlende Ablage, deren Maße ich einem alten Buch über ähnliche Maschinen so ungefähr entnehmen konnte. Ein zweiter Schlosser, damals noch auf einem Hof in der Kastanienallee, in der es heute nur noch ständig wechselnde Firlefanzgeschäfte gibt, baute mir die Befestigung für den Aufzug und eine Muffe zum Festhalten des Schwungrades. Anschließend wurden die vier Walzen neu mit Gummi bezogen. Und dann verdiente diese Maschine zusammen mit einem Handtiegel nicht nur meinen Lebensunterhalt, sondern auch das Geld für meinen ersten Heidelberger Tiegel. Der ihr dann die Arbeit abnahm. Im Jahr 2013 zog die Maschine mit mir nach Weißensee in die jetzige Werkstatt. Aber hier hatte sie kaum noch zu tun, obwohl sie, das ist einer ihrer Vorzüge, ein etwas größeres Druckformat als der Heidelberger hat und auch über das Format weit herausragende Materialen bedrucken kann. Nun ist es also an der Zeit für einen neuen Standort, und für 3500 Euro brutto kann die Maschine abgeholt werden. ## 2020-06-21 ### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen) #### Mehrsprachige Beamerfolien erstellen – Teil 2 Basierend auf dem letzten Blog-Artikel dazu und einer Frage, die ich 2014 auf TSX gestellt habe, habe ich den Code für mehrsprachige Beamer-Folien angepasst. \documentclass[ngerman]{beamer} \usepackage{comment} \makeatletter \newif\if@ngerman \newif\if@option@ngerman \DeclareOption{ngerman}{% \@ngermantrue \@option@ngermantrue } \ProcessOptions*\relax \newcommand*{\ifngerman}{% \if@ngerman \expandafter\@firstoftwo \else \expandafter\@secondoftwo \fi } \makeatother \ifngerman{ \usepackage[main=ngerman]{babel} \includecomment{DE} \excludecomment{EN} }{ \usepackage[main=english]{babel} \includecomment{EN} \excludecomment{DE} } \begin{document} \begin{DE} \begin{frame}[fragile]{Hallo Welt} Hallo Welt \end{frame} \end{DE} \begin{EN} \begin{frame}[fragile]{Hello World} Hello World \end{frame} \end{EN} \end{document} ### Uwe Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik. üääüüöü–üöü–üöü– ## 2020-06-20 ### LaTeX.net #### The Island of TeX The islander’s talk at DANTE 2020. ## 2020-06-08 ### LaTeX.net #### About LaTeX.net On LaTeX-Community.org, founded January 2007, many authors published articles about LaTeX and related tools. The site has been renamed to LaTeX.net. The article database has been changed from Joomla to a modern WordPress CMS. The accompanying forum has been renamed to LaTeX.org. The LaTeX network is actually more than just this. Here comes a list. These sites are maintained by Stefan Kottwitz. All of the servers and web sites here are supported by DANTE e.V., the German speaking TeX user group. For several years now, DANTE covered the provider and hardware costs for two professional servers that have enough resources to run various virtual machines for different purposes. This is what runs on this DANTE supported hardware: ## Forums ## Galleries ## Software Archives and Mirrors ## FAQs ## Blogs ## Tools Photo by Taylor Vick on Unsplash ## 2020-06-06 ### LaTeX.net #### Semi-automatic plotting Producing data plots is an important part of doing research work. Making good looking plots is not easy, and getting them right as well is a real challenge. Perhaps the best way of producing plots, whether for use with LaTeX or otherwise, is to use the pgfplots package. For a general overview of using pgfplots effectively, see my TUGBoat article . Using a programmatic approach to plotting has several advantages, as the plots you get are easy to keep consistent. That’s particularly useful if several people are preparing plots: using a GUI-based approach, it’s hard for multiple workers to stick exactly to the same look. So it is worth putting some effort into setting up templates for pgfplots: basic .tex files which can be modified easily and reused multiple times. Putting a bit of effort into developing templates also makes it easier to use data directly from a lot of specialist systems. Many data file formats can be read as either comma or space separated files, but it can take a little effort to get this right. So by working on the basics, you can save yourself time later. There is another advantage to setting up well documented templates. Not everyone is a LaTeX expert: in my area, most people are not even day to day LaTeX users. So making clear templates which can be used by altering a few key settings is a great way to make LaTeX results accessible to more people. ## Setting up Before you can start developing a template, you need of course to have some data and produce a one-off plot. That process is covered in the TUGBoat article I mentioned earlier. There are then two big things to worry about: generalising the .tex, and adding enough comments to let other people use the template. That second point very important, as is talking to other people to get things right: there’s no use in creating a template that no-one can use! As an example, I’ll use a plot of an infra-red spectrum: this is similar to one in the TUGBoat article. The original version looks like this: \documentclass{standalone} \usepackage[T1]{fontenc} \usepackage{helvet} \sansmath \renewcommand{\rmfamily}{\sffamily} \usepackage{pgfplots} \pgfplotsset { compat = newest, every tick/.append style = thin } \pgfkeys{/pgf/number format/set thousands separator = } \usepackage{siunitx} \sisetup{mode = text} \begin{document} \begin{tikzpicture}[font = \sffamily] \begin{axis} [ x dir = reverse, xlabel = Wavenumber/\si{\per\centi\metre}, xmax = 2100, xmin = 1800, ylabel = Milliabsorbance, ymax = 34 ] \addplot[color = black, mark = none] table {example.txt}; \node[coordinate, pin = {[rotate=90]right:1884}] at (axis cs:1884,1.3) { }; \node[coordinate, pin = {[rotate=90]right:1922}] at (axis cs:1922,1.3) { }; \node[coordinate, pin = {[rotate=90]right:1965}] at (axis cs:19651,1.3) { }; \node[coordinate, pin = {[rotate=90]right:1965}] at (axis cs:1965,1.3) { }; \node[coordinate, pin = {[rotate=90]right:2076}] at (axis cs:2076,1.3) { }; \end{axis} \end{tikzpicture} ## From one plot to many plots There are several things to notice about the example. First, there are no comments: that’s fine for me (provided I remember how it works), but what about my coworkers? Second, everything is hard coded, for example the file containing the raw data, which is pretty hard to find. Third, I had to pre-modify the data file to get it working: the .txt file is based on an instrument file which is in a text format but which contains lines I needed to remove and scale. Finally, there is a lot of repetition in the pin part, which would be better handled using a loop. The most important change to make is probably adding comments: that’s true of any form of programming. In this case, that means labelling up the lines which should be changed, and saying what should go in them. So for example I would the settings for the axes to read \begin{axis} [ x dir = reverse, xlabel = Wavenumber/\si{\per\centi\metre}, xmax = 2100, % Alter "2100" to change x-max xmin = 1800, % Alter "1800" to change x-min ylabel = Milliabsorbance, % Set ymax value to allow space for labels % Alter "34" to set y-max, or comment out for autoscale ymax = 34 ] Making the template more flexible means moving some parts to macros which stand out. In this template, the most important thing is where the data comes from. So I would make that a macro right at the start of the file % The file name for the raw data goes here \newcommand*{\datafile}{example.txt} Later in the file, I then use \addplot[color = black, mark = none] table {\datafile}; Of course, I could have simply added a comment, but that does not work so well for this type of ‘hidden’ setting. I find that the key-value lists used a lot by pgfplots work fine with comments, but for other settings using a well-named macro works better. Making templates that work directly from instrument data rather than having to post-process in a spreadsheet can require a bit of effort. Provided you can save data in a text format (space-, tab- or comma-delimited), the pay-off is that you only have to do the job once, and can then forget about the problem: if you have to post-process every time, it’s easy to make mistakes. In the example, I had to remove some lines at the start of the instrument file to make it usable: easy to set up using \addplot[color = black, mark = none] table[skip first n = 2] {\datafile}; Dealing with comma-separated files is also easy \pgfplotsset{table/col sep = comma} (the standard setting for pgfplots is whitespace delimited). Scaling or shifting data points is sometimes necessary, and again pgfplots can help as it will work with expressions for x and y, not just values. We can therefore have something like \addplot[color = black, mark = none] table [ skip first n = 4, x expr = \thisrowno{0} + 10, y expr = 1000000 * \thisrowno{1} ] where the column numbers for a table start at 0 (usually the x value) and work up. Of course, if the values you need to shift or multiply by are variable at all, you can store them as commands. Finally, we can use loops to deal with repetition. I pointed out that where I added some text markers in the original, things were repetitive and a loop would work \pgfplotsinvokeforeach{1884,1922,1965,2076}{% Alter numbers as needed \node[coordinate, pin = {[rotate=90]right:#1}] at (axis cs:#1,23) { }; % Alter "1.3" to set height of labels } TikZ experts might wonder why I haven’t used \pgfforeach here: it doesn’t work! ## Putting it together So what does the completed template look like? % Template for plotting a single IR spectrum % The file name for the raw data goes here \newcommand*{\datafile}{example.asc} \documentclass{standalone} \usepackage[T1]{fontenc} \usepackage{helvet} \usepackage[EULERGREEK]{sansmath} \sansmath \renewcommand{\rmfamily}{\sffamily} \usepackage{pgfplots} \pgfplotsset { compat = newest, every tick/.append style = thin } \pgfkeys{/pgf/number format/set thousands separator = } \usepackage{siunitx} \sisetup{mode = text} \begin{document} \begin{tikzpicture}[font = \sffamily] \begin{axis} [ x dir = reverse, xlabel = Wavenumber/\si{\per\centi\metre}, xmax = 2100, % Alter "2100" to change x-max xmin = 1800, % Alter "1800" to change x-min ylabel = Milliabsorbance, % Set ymax value to allow space for labels ymax = 34 % Alter "34" to set y-max, or comment out for autoscale ] \addplot[color = black, mark = none] table[skip first n = 2] {\datafile}; % A list of labels: put all of the positions in the list. \pgfplotsinvokeforeach{1884,1922,1965,2076}{% Alter numbers as needed \node[coordinate, pin = {[rotate=90]right:#1}] at (axis cs:#1,23) { }; % Alter "1.3" to set height of labels } \end{axis} \end{tikzpicture} \end{document} The result is shown in the figure. ## Programming for flexibility Of course, you can make templates as simple or as complex as you like. For example, we have some data that can come from one of three machines. Two save directly in text-based files, but the formats are different. The third can only export data, in .csv format, which is different again from the other two! I could have written three templates, but as my non-LaTeX using colleagues need to use them too, a programmatic approach looked better. So I worked out the three different settings needed, then set up some code to work out the file extension and set up accordingly % The file name for the raw data goes here \newcommand*{\datafile}{100mvn.ocw} % Change "100mvn.par" % This does the auto-detection of file type % You don't need to change anything \newcommand*{\xcolumn}{0} \newcommand*{\ycolumn}{1} \newcommand*{\ignorelines}{0} \newcommand*{\ext}{} \newcommand*{\getext}{} \def\getext#1.#2\stop{% \expandafter\ifx\expandafter\relax\detokenize{#2}\relax \renewcommand{\ext}{#1}% \expandafter\getextaux \else \expandafter\getext \fi #2\stop } \newcommand*{\getextaux}{} \def\getextaux#1\stop{% \ifnum\pdfstrcmp{\ext}{par}=0 % \renewcommand*{\ignorelines}{110} \renewcommand*{\xcolumn}{2} \renewcommand*{\ycolumn}{3} \else \ifnum\pdfstrcmp{\ext}{ocw}=0 % \renewcommand*{\ignorelines}{2} \AtBeginDocument{% \pgfplotsset{table/col sep = space} } \fi \fi } \expandafter\getext\datafile.\stop You might not want to go that far, but the point is that using LaTeX gives you the possibility to program this kind of thing. You only need to set it up once, so it is worth considering. ## Conclusions With a bit of effort, you can use pgfplots to produce sophisticated templates that can be used to produce high quality plots with ease. This helps you keep you data presentation consistent, and can also be used where several workers have to produce similar output: vital if one person (you!) is to avoid doing all of the work. #### TikZ Library for Structural Analysis At university it is always a very time consuming work to create new assignments, and tests; especially when those tasks include drawing graphics. In the field of structural engineering those small structures are a key part for teaching. For this reason I developed, in cooperation with the Institute for Structural Analysis at the Graz University of Technology, a TikZ library for Structural Analysis. There are two different types of libraries available: one for 2D structures (structuralanalysis.sty) and one for 3D structures (3dstructuralanalysis.sty). In the following article only the 2D library will be discussed, but the principles and methods are the same for 3D structures. ### Contents ### Principles TikZ is a very powerful tool; however, unfortunately not everyone is used to this part of LaTeX. Therefore, in addition to the creation of the library the second goal was to keep the usage as simple as possible. So that: • anyone can use this library without (deeper) knowledge in TikZ • skilled users can easily modify and customise the code • the principle of this library can be used for any other library ### Getting Started #### Installation Download the .sty file in the right directory and add it to the LaTeX file like: \usepackage{structuralanalysis} #### LaTeX Environment Like every TikZ graph, needs also this library the \begin{tikzpicture} ... \end{tikzpicture} environment. ### Elements #### Basic Commands The library provides 10 different commands: • \point • \beam • \support • \hinge • \load or \lineload and \temperature • \internalforces • \dimensioning • \influenceline • \notation • \addon For each element (command) are different options available. Obligatory options are marked with {curley brackets} and optional values are marked with [square brackets]. The first type is a must have criteria. In contrast, the optional input is not required to be entered. An easy example is the following single force: \load{type}{insertion point}[rotation][length or included angle][loaddistance]; #### Manual More specific information about the elements and their options can be found in the manual. The manual is written in German, but section 1 provides a table with all elements and options; furthermore, the code is also given for each picture in the manual. ### Examples The easiest way to create a structure is the list above, starting with \point and ending with \addon. The following examples shall give a first impression how drawings can be generated. In the manual both examples are explained in detail. #### 2D Simplified Roof \begin{tikzpicture} \scaling{.65}; \point{a}{0}{1}; \point{b}{3}{1}; \point{c}{11}{3}; \point{d}{19}{1}; \point{e}{22}{1}; \point{f}{3}{0}; \point{g}{11}{-2}; \point{h}{19}{0}; \beam{1}{a}{b}[0][1]; \beam{1}{b}{c}[1][1]; \beam{1}{c}{d}[1][1]; \beam{1}{d}{e}[1][0]; \beam{1}{f}{b}; \beam{1}{d}{h}; \beam{2}{f}{g}; \beam{2}{g}{h}; \beam{2}{g}{c}; \support{1}{f}; \support{2}{h}; \hinge{1}{f}; \hinge{1}{h}; \hinge{1}{g}; \hinge{2}{c}[<!-- no bbcode -->b][d]; \lineload{2}{a}{b}[1][1][.5]; \lineload{2}{b}{c}; \dimensioning{1}{a}{b}{-2.5}[$3,0$]; \dimensioning{1}{b}{c}{-2.5}[$8,0$]; \dimensioning{1}{c}{d}{-2.5}[$8,0$]; \dimensioning{1}{d}{e}{-2.5}[$3,0$]; \dimensioning{2}{f}{a}{-1}[$1,0$]; \dimensioning{2}{g}{f}{-1}[$2,0$]; \dimensioning{2}{a}{c}{-1}[$2,0$]; \influenceline{a}{e}{3}[.3]; \notation{1}{a}{$1$}[left]; \notation{1}{b}{$2$}[below right=2mm]; \notation{1}{c}{$3$}; \notation{1}{d}{$4$}[above]; \notation{1}{e}{$5$}[above]; \notation{1}{f}{$6$}[left=2mm]; \notation{1}{g}{$7$}[below=2mm]; \notation{1}{h}{$8$}[right=2mm]; \notation{4}{f}{g}[$S$]; \end{tikzpicture} #### 3D Support Construction By using the library 3dstructuralanalysis, the following graph can be created in a very short time: \setcoords{-25}{10}[1][1.2] \setaxis{2} %\showpoint \begin{tikzpicture}[coords] \dpoint{a}{0}{0}{0}; \dpoint{b}{3}{0}{0}; \dpoint{c}{6}{0}{0}; \dpoint{d}{9}{0}{0}; \dpoint{e}{12}{0}{0}; \dpoint{f}{0}{3}{0}; \dpoint{g}{3}{3}{0}; \dpoint{h}{6}{3}{0}; \dpoint{i}{9}{3}{0}; \dpoint{j}{12}{3}{0}; \daxis{1}{a}; \dbeam{1}{f}{b}; \dbeam{1}{b}{h}; \dbeam{1}{h}{d}; \dbeam{1}{d}{j}; \dbeam{3}{a}{e}; \dbeam{3}{f}{j}; \dbeam{3}{a}{f}; \dbeam{3}{b}{g}; \dbeam{3}{c}{h}; \dbeam{3}{d}{i}; \dbeam{3}{e}{j}; \dsupport{1}{b}; \dsupport{1}{h}[0][0]; \dsupport{1}{d}[0]; \dhinge{2}{b}[f][h][1]; \dhinge{2}{h}[<!-- no bbcode-->b][d][1]; \dhinge{2}{d}[h][j][1]; \dlineload{5}{0}{f}{b}[.5][.5][.11]; \dlineload{5}{0}{b}{h}[.5][.5][.11]; \dlineload{5}{0}{h}{d}[.5][.5][.11]; \dlineload{5}{0}{d}{j}[.5][.5][.11]; \ddimensioning{xy}{f}{g}{4.5}[$3~m$]; \ddimensioning{xy}{g}{h}{4.5}[$3~m$]; \ddimensioning{xy}{h}{i}{4.5}[$3~m$]; \ddimensioning{xy}{i}{j}{4.5}[$3~m$]; \ddimensioning{yx}{e}{j}{13}[$3~m$]; \dnotation{1}{f}{$q=10~kN/m$}[above left=3mm]; \dnotation{1}{b}{$A$}[below left]; \dnotation{1}{h}{$C$}[right=2mm]; \dnotation{1}{d}{$B$}[below left]; \end{tikzpicture} ### Downloads ### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen) #### Mehrsprachige Beamer-Folien erstellen Unter https://tex.stackexchange.com/questions/443714/bilingual-slides-beamer-comment-package-and-non-ascii-characters-umlauts-dia gibt es ein gutes Beispiel, wie man mehrsprachige Beamer-Folien erstellen kann. Je nach gesetztem \newcommand{\lvlang}{EN} wird entweder die englische oder deutsche Version erzeugt. Der Code müsste sich noch verbessern lassen, wenn man beispielsweise globale Klassenoptionen wie english oder ngerman auswertet. Nachtrag: Siehe dazu https://www.uweziegenhagen.de/?p=4352 Hier ein vollständiges Beispiel: \documentclass{beamer} \newcommand{\lvlang}{EN} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{comment} \long\def\WriteCommentLine#1{\immediate\write\CommentStream{\unexpanded{#1}}} \let\ThisComment\WriteCommentLine \usepackage{ifthen} \newcommand{\iflvlangde}[2]{% \ifthenelse{\equal{\lvlang}{DE}}{#1}{#2}% } \makeatletter \iflvlangde{ \usepackage[main=ngerman]{babel} \includecomment{DE} \excludecomment{EN} }{ \usepackage[main=english]{babel} \includecomment{EN} \excludecomment{DE} } \makeatother \begin{document} \begin{DE} \begin{frame}[fragile]{Hallo Welt} Hallo Welt \end{frame} \end{DE} \begin{EN} \begin{frame}[fragile]{Hello World} Hello World \end{frame} \end{EN} \end{document} ### Uwe Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik. üääüüöü–üöü–üöü– ### LaTeX.net #### Drawing with the tikz-3dplot Package When I started working on my thesis dissertation using LaTeX, I discovered the TikZ package for drawing vector-based figures. I needed a way to easily draw three-dimensional figures, and so I put together a few handy tools in the tikz-3dplot package. This package builds on TikZ, providing an easy way to rotate the perspective when drawing three-dimensional shapes using basic shapes in a tikzpicture environment. Let’s explore some examples of what tikz-3dplot can do. – A contribution to the LaTeX and Graphics contest – This article is available for reading and for download in pdf format ### The Basics Let’s draw a cube, with side length of 2. To help illustrate the comparison, we’ll draw a grid in the xy plane, and also show the x, y, and z axes. \begin{tikzpicture} [cube/.style={very thick,black}, grid/.style={very thin,gray}, axis/.style={->,blue,thick}] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[grid] (\x,-0.5) -- (\x,2.5); \draw[grid] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[axis] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[axis] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[axis] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the top and bottom of the cube \draw[cube] (0,0,0) -- (0,2,0) -- (2,2,0) -- (2,0,0) -- cycle; \draw[cube] (0,0,2) -- (0,2,2) -- (2,2,2) -- (2,0,2) -- cycle; %draw the edges of the cube \draw[cube] (0,0,0) -- (0,0,2); \draw[cube] (0,2,0) -- (0,2,2); \draw[cube] (2,0,0) -- (2,0,2); \draw[cube] (2,2,0) -- (2,2,2); \end{tikzpicture} \tdplotsetmaincoords{60}{125} \begin{tikzpicture} [tdplot_main_coords, cube/.style={very thick,black}, grid/.style={very thin,gray}, axis/.style={->,blue,thick}] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[grid] (\x,-0.5) -- (\x,2.5); \draw[grid] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[axis] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[axis] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[axis] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the top and bottom of the cube \draw[cube] (0,0,0) -- (0,2,0) -- (2,2,0) -- (2,0,0) -- cycle; \draw[cube] (0,0,2) -- (0,2,2) -- (2,2,2) -- (2,0,2) -- cycle; %draw the edges of the cube \draw[cube] (0,0,0) -- (0,0,2); \draw[cube] (0,2,0) -- (0,2,2); \draw[cube] (2,0,0) -- (2,0,2); \draw[cube] (2,2,0) -- (2,2,2); \end{tikzpicture} In the default configuration, shown on the left, the xy plane lies in the same plane as the page. The z-axis extends down and to the left, giving the illusion of depth. This is a useful representation of a three-dimensional space as is, but gives little in the range of customization. The tikz-3dplot package can redefine the perspective for viewing this three-dimensional space. In the tikz-3dplot configuration, the z-axis points in the vertical direction, and the viewed perspective of the xy plane can be specified using the user-specified values θ and φ (in degrees). These angles define the direction from which the three-dimensional space is viewed, using the standard definition of the polar and azimuthal angles from polar coordinates. To specify the display orientation, use the command \tdplotsetmaincoords{θ}{φ} before the tikzpicture environment, and include the tdplot_main_coords style within any drawing command. Alternatively, as seen in this example, you can include the tdplot_main_coords style within the global style settings of the tikzpicture environment. As suggested by the name, tdplot_main_coords, I refer to this coordinate frame as the “main” coordinate frame. It provides the base through which you can perform all drawing operations. It may seem a bit restrictive that the z-axis of the main coordinate frame can only the vertical direction. If you wish to define a more general orientation, there is a second, “rotated” coordinate frame that can be specified relative to the orientation of the main coordinate frame. Let’s take a look at this cube example again, drawn in the rotated coordinate frame. \tdplotsetmaincoords{60}{120}% \tdplotsetrotatedcoords{0}{20}{0}% \begin{tikzpicture} [tdplot_rotated_coords, cube/.style={very thick,black}, grid/.style={very thin,gray}, axis/.style={->,blue,thick}, rotated axis/.style={->,purple,thick}] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[grid] (\x,-0.5) -- (\x,2.5); \draw[grid] (-0.5,\y) -- (2.5,\y); } %draw the main coordinate frame axes \draw[axis,tdplot_main_coords] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[axis,tdplot_main_coords] (0,0,0) -- (0,3,0) node[anchor=north west]{$y$}; \draw[axis,tdplot_main_coords] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the rotated coordinate frame axes \draw[rotated axis] (0,0,0) -- (3,0,0) node[anchor=west]{$x'$}; \draw[rotated axis] (0,0,0) -- (0,3,0) node[anchor=south west]{$y'$}; \draw[rotated axis] (0,0,0) -- (0,0,3) node[anchor=west]{$z'$}; %draw the top and bottom of the cube \draw[cube] (0,0,0) -- (0,2,0) -- (2,2,0) -- (2,0,0) -- cycle; \draw[cube] (0,0,2) -- (0,2,2) -- (2,2,2) -- (2,0,2) -- cycle; %draw the edges of the cube \draw[cube] (0,0,0) -- (0,0,2); \draw[cube] (0,2,0) -- (0,2,2); \draw[cube] (2,0,0) -- (2,0,2); \draw[cube] (2,2,0) -- (2,2,2); \end{tikzpicture} Here, I show the axes for both the main coordinate frame (xyz) and rotated coordinate frame (xyz‘). Using the command \tdplotsetrotatedcoords{θz}{θy}{θz}, the rotated coordinate frame is defined by taking the orientation of the main coordinate frame, and then performing the Euler angle rotations (θz, θy, θz) (in degrees) to define the rotated coordinate frame. The coordinate transformation for the rotated coordinate frame is stored in the tdplot_rotated_coords style. In this example, I simply rotated about the y-axis of the main coordinate frame. ### Examples Defining tdplot_main_coord and tdplot_rotated_coords is just the beginning. tikz-3dplot provides a bunch of handy tools to make it easier to work in a three-dimensional space. #### Defining Coordinates For example, the command \tdplotsetcoord{r}{θ}{φ} defines a coordinate using spherical coordinates r, θ, φ. More than that, this handy command also defines points that can be useful for projections on the axes and their shared planes. Consider the following example, where the coordinate (P) is defined in the three-dimensional space using spherical polar coordinates. \tdplotsetmaincoords{60}{120} \begin{tikzpicture} [scale=3, tdplot_main_coords, axis/.style={->,blue,thick}, vector/.style={-stealth,red,very thick}] %standard tikz coordinate definition using x, y, z coords \coordinate (O) at (0,0,0); %tikz-3dplot coordinate definition using r, theta, phi coords \tdplotsetcoord{P}{.8}{55}{60} %draw axes \draw[axis] (0,0,0) -- (1,0,0) node[anchor=north east]{$x$}; \draw[axis] (0,0,0) -- (0,1,0) node[anchor=north west]{$y$}; \draw[axis] (0,0,0) -- (0,0,1) node[anchor=south]{$z$}; %draw a vector from O to P \draw[vector] (O) -- (P); \end{tikzpicture} \tdplotsetmaincoords{60}{120} \begin{tikzpicture} [scale=3, tdplot_main_coords, axis/.style={->,blue,thick}, vector/.style={-stealth,red,very thick}, vector guide/.style={dashed,red,thick}] %standard tikz coordinate definition using x, y, z coords \coordinate (O) at (0,0,0); %tikz-3dplot coordinate definition using r, theta, phi coords \tdplotsetcoord{P}{.8}{55}{60} %draw axes \draw[axis] (0,0,0) -- (1,0,0) node[anchor=north east]{$x$}; \draw[axis] (0,0,0) -- (0,1,0) node[anchor=north west]{$y$}; \draw[axis] (0,0,0) -- (0,0,1) node[anchor=south]{$z$}; %draw a vector from O to P \draw[vector] (O) -- (P); %draw guide lines to components \draw[vector guide] (O) -- (Pxy); \draw[vector guide] (Pxy) -- (P); \end{tikzpicture} In the left diagram, it is hard to identify where the vector lies in the three-dimensional space. In the right diagram, I make use of the (automatically generated) projection coordinate (Pxy), which lies in the xy plane below (P), to illustrate the orientation of the vector. #### Drawing Circles and Arcs To draw a circle or arc, the \tdplotdrawarc command is provided. Here, you specify the center of the circle/arc, the radius, the start and end angles, and label notes. Here are a couple examples that use arcs and circles. \tdplotsetmaincoords{60}{120} \begin{tikzpicture} [scale=3, tdplot_main_coords, axis/.style={->,blue,thick}, vector/.style={-stealth,red,very thick}, vector guide/.style={dashed,red,thick}, angle/.style={red,thick}] %standard tikz coordinate definition using x, y, z coords \coordinate (O) at (0,0,0); %tikz-3dplot coordinate definition using r, theta, phi coords \tdplotsetcoord{P}{.8}{55}{60} %draw axes \draw[axis] (0,0,0) -- (1,0,0) node[anchor=north east]{$x$}; \draw[axis] (0,0,0) -- (0,1,0) node[anchor=north west]{$y$}; \draw[axis] (0,0,0) -- (0,0,1) node[anchor=south]{$z$}; %draw a vector from O to P \draw[vector] (O) -- (P); %draw guide lines to components \draw[vector guide] (O) -- (Pxy); \draw[vector guide] (Pxy) -- (P); %draw an arc illustrating the angle defining the orientation \tdplotdrawarc[angle]{(O)}{.35}{0}{60}{anchor=north}{$\phi$} %define the rotated coordinate frame to lie in the "theta plane" \tdplotsetthetaplanecoords{55} \tdplotdrawarc[tdplot_rotated_coords,angle]{(O)}{.35}{0}{55} {anchor=south west}{$\theta$} \end{tikzpicture} \tdplotsetmaincoords{55}{5} \begin{tikzpicture} [scale=3, tdplot_main_coords, curve/.style={red,densely dotted,thick}] \coordinate (O) at (0,0,0); \foreach \angle in {-90,-75,...,90} { %calculate the sine and cosine of the angle \tdplotsinandcos{\sintheta}{\costheta}{\angle}% %define a point along the z-axis through which to draw %a circle in the xy-plane \coordinate (P) at (0,0,\sintheta); %draw the circle in the main frame \tdplotdrawarc[curve]{(P)}{\costheta}{0}{360}{}{} %define the rotated coordinate frame based on the angle \tdplotsetthetaplanecoords{\angle} %draw the circle in the rotated frame \tdplotdrawarc[curve,tdplot_rotated_coords]{(O)}{1}{0}{360}{}{} } \end{tikzpicture} The left example is an extension of the vector example shown earlier. An arc was added in the xy plane to illustrate the azimuthal angle, φ, and another arc was added to illustrate the polar angle, θ. In the right example, a series of circles are drawn to represent longitudinal and latitudinal lines on a sphere. To make these examples, a few useful helper functions are used. First, the \tdplotsetthetaplanecoords{φ} function gives a convenient way of placing rotated coordinate frame such that the xy‘ plane is lined up to draw the polar angle, θ. Second, the \tdplotsinandcos{\sintheta}{\costheta}{θ} command takes the specified angle, θ (in degrees), and stores the sine and cosine value of that angle in the macros \sintheta and \costheta. Note that you can use any name in place of \sintheta and \costheta for your convenience. #### Drawing Surfaces Drawing lines and curves can be great fun, but what if you wanted to represent a solid object with opaque surfaces? With proper planning and careful consideration of which surfaces are drawn first, you can render simple shapes. \tdplotsetmaincoords{60}{125} \begin{tikzpicture} [tdplot_main_coords, grid/.style={very thin,gray}, axis/.style={->,blue,thick}, cube/.style={opacity=.5,very thick,fill=red}] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[grid] (\x,-0.5) -- (\x,2.5); \draw[grid] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[axis] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[axis] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[axis] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the bottom of the cube \draw[cube] (0,0,0) -- (0,2,0) -- (2,2,0) -- (2,0,0) -- cycle; %draw the back-right of the cube \draw[cube] (0,0,0) -- (0,2,0) -- (0,2,2) -- (0,0,2) -- cycle; %draw the back-left of the cube \draw[cube] (0,0,0) -- (2,0,0) -- (2,0,2) -- (0,0,2) -- cycle; %draw the front-right of the cube \draw[cube] (2,0,0) -- (2,2,0) -- (2,2,2) -- (2,0,2) -- cycle; %draw the front-left of the cube \draw[cube] (0,2,0) -- (2,2,0) -- (2,2,2) -- (0,2,2) -- cycle; %draw the top of the cube \draw[cube] (0,0,2) -- (0,2,2) -- (2,2,2) -- (2,0,2) -- cycle; \end{tikzpicture} \tdplotsetmaincoords{60}{125} \begin{tikzpicture}[ tdplot_main_coords, grid/.style={very thin,gray}, axis/.style={->,blue,thick}, cube/.style={very thick,fill=red}, cube hidden/.style={very thick,dashed}] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[grid] (\x,-0.5) -- (\x,2.5); \draw[grid] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[axis] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[axis] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[axis] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the front-right of the cube \draw[cube] (2,0,0) -- (2,2,0) -- (2,2,2) -- (2,0,2) -- cycle; %draw the front-left of the cube \draw[cube] (0,2,0) -- (2,2,0) -- (2,2,2) -- (0,2,2) -- cycle; %draw the top of the cube \draw[cube] (0,0,2) -- (0,2,2) -- (2,2,2) -- (2,0,2) -- cycle; %draw dashed lines to represent hidden edges \draw[cube hidden] (0,0,0) -- (2,0,0); \draw[cube hidden] (0,0,0) -- (0,2,0); \draw[cube hidden] (0,0,0) -- (0,0,2); \end{tikzpicture} The left example uses fill color transparency to illustrate surfaces hidden behind others. Here, the covered and back edges of the cube are distinguished by having the fill for the front surfaces drawn over top. The right example has opaque front surfaces of the cube drawn first, and then the back edges are illustrated using dashed lines. In both situations, the order of drawing depends on the perspective. If you change the orientation of the coordinate frame, you will need to be careful about whether the drawing order needs to change. In the case with dashed lines, you may even need to reassign roles to the components of the object. Another example of surface plots is the \tdplotsphericalsurfaceplot command. This command was developed to allow me to plot complex spherical harmonics, where the radius and hue of the surface is plotted as a function of the polar and azimuthal angles. \tdplotsetmaincoords{70}{135} \begin{tikzpicture}[scale=4,line join=bevel,tdplot_main_coords, fill opacity=.5] \pgfsetlinewidth{.2pt} \tdplotsphericalsurfaceplot[parametricfill]{72}{36}{sin(\tdplottheta)*cos(\tdplottheta)}{black}{\tdplotphi}% {\draw[color=black,thick,->] (0,0,0) -- (1,0,0) node[anchor=north east]{$x$};}% {\draw[color=black,thick,->] (0,0,0) -- (0,1,0) node[anchor=north west]{$y$};}% {\draw[color=black,thick,->] (0,0,0) -- (0,0,1) node[anchor=south]{$z$};}% \end{tikzpicture} Here, I am plotting the function r = sin(θ)cos(θ), and using φ as the parameter to choose the surface fill hue. The instructions for \tdplotsphericalsurfaceplot define the angular step sizes, the function to plot, the line style, the fill style, and instructions for drawing axes. Unlike the manual surface plot examples shown earlier, the \tdplotsphericalsurfaceplot command does the work of determining how to appropriately draw the surface so that surfaces and edges drawn on the back side are appropriately rendered below those on the front. The only downside with this is that it takes some time to render, so you may want to look into externalizing these figures. ### Limitations When drawing shapes in tikz-3dplot, only simple shapes like line segments and arcs behave properly, whereas more involved shapes like rectangles and grids do not adhere to the sense of rotated coordinate system. Let’s look at the first example again, where we use the rectangle command to draw the top and bottom of the cube, rather than a series of line segments. \begin{tikzpicture} %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[gray,very thin] (\x,-0.5) -- (\x,2.5); \draw[gray,very thin] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[->] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[->] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[->] (0,0,0) -- (0,0,3) node[anchor=west]{$z$}; %draw the top and bottom of the cube \draw[very thick] (0,0,0) rectangle (2,2,0); \draw[very thick] (0,0,2) rectangle (2,2,2); %draw the edges of the cube \draw[very thick] (0,0,0) -- (0,0,2); \draw[very thick] (0,2,0) -- (0,2,2); \draw[very thick] (2,0,0) -- (2,0,2); \draw[very thick] (2,2,0) -- (2,2,2); \end{tikzpicture} \tdplotsetmaincoords{60}{125} \begin{tikzpicture}[tdplot_main_coords] %draw a grid in the x-y plane \foreach \x in {-0.5,0,...,2.5} \foreach \y in {-0.5,0,...,2.5} { \draw[gray,very thin] (\x,-0.5) -- (\x,2.5); \draw[gray,very thin] (-0.5,\y) -- (2.5,\y); } %draw the axes \draw[->] (0,0,0) -- (3,0,0) node[anchor=west]{$x$}; \draw[->] (0,0,0) -- (0,3,0) node[anchor=west]{$y$}; \draw[->] (0,0,0) -- (0,0,3) node[anchor=west]{$z\$};
%draw the top and bottom of the cube
\draw[very thick] (0,0,0) rectangle (2,2,0);
\draw[very thick] (0,0,2) rectangle (2,2,2);
%draw the edges of the cube
\draw[very thick] (0,0,0) -- (0,0,2);
\draw[very thick] (0,2,0) -- (0,2,2);
\draw[very thick] (2,0,0) -- (2,0,2);
\draw[very thick] (2,2,0) -- (2,2,2);
\end{tikzpicture}
If you look carefully at the rotated diagram, you’ll notice that the rectangles are drawn with the correct beginning and end points, but the overall shape conforms to the original coordinate system of the page.
For more information, I recommend you have a look at the package, located at www.ctan.org/pkg/tikz-3dplot.
About the Author:Jeff Hein is the author of the tikz-3dplot package. He maintains a blog for this package on tikz3dplot.wordpress.com.
# The first LaTeX prerelease for 2020-10-01 is available for testing
A few days ago we have submitted a new LaTeX development format1 to CTAN and by now it should be available to all users using MiKTeX or TeX Live (on any operating system).
This format allows you to test the upcoming LaTeX release scheduled for 2020-10-01 with your documents or packages. Such testing is particularly important for package maintainers to verify that changes to the core LaTeX haven’t introduced incompatibilities with existing code. We try to identify any such problem beforehand, but such an undertaking is necessarily incomplete, which is why we ask for user testing.
Besides developers we also ask ordinary users to try out the new release candidate, because the more people are testing the new format, the higher the chances that any hidden problems are identified before the final release in February hits the streets.
Processing your documents with the prerelease is straight forward. All you have to do is to replace the invocation command by appending -dev to the executable, e.g., on the command line you would run
pdflatex-dev myfile or lualatex-dev myfile or xelatex-dev myfile
instead of using pdflatex, lualatex or xelatex. If you use an integrated editing environment, then it depends on the system how to configure it to use an alternative format; but in any case the necessary modification should be straight forward.
## Main features of the first prerelease for 2020-10-01
We have been quite busy (did Corona help?) and so already this first prerelease contains close to thirty smaller and larger fixes and enhancements. A full list is given in a draft version of ltnews32 which you should be able to read by running
texdoc ltnews32
on the command line (or by any other means available at your operating system—somewhere there should be a file called ltnews32.pdf that you can open with a PDF reader). The draft version is also available from our website as LaTeX2e News Issue 32 draft.
In this post I only touch two of the most important topics, but many others are worth exploring too, so please check that documentation out.
### Providing xparse as part of the format
In the previous release we added the LaTeX3 programming layer to the LaTeX format to improve the loading speed when packages using expl3 are used (such as fontspec or xparse). In the upcoming release we are now extending this support by integrating xparse so that the extended interface for defining document-level commands becomes available out of the box.
This enables users and most importantly package developers to easily define LaTeX commands with multiple optional arguments or other syntax features with ease. For details, check out the xparse documentation, e.g., via texdoc xparse.
### Improving the font series handling
In the previous release we extended NFSS (the new font selection scheme) to better support modern fonts that offer different font faces, e.g., condensed, semi-bold, etc., and make them work seamlessly with each other. Experiences with the extended interface showed that for some use cases adequate support was still missing or that in special setups the algorithms sometimes selected a wrong font series value. These cases have now been resolved and additional support commands have been added. For example, with
\IfFontSeriesContextTF{〈context〉} {〈true code〉}{〈false code〉}
you can now define commands that behave differently depending on the current font series context. The 〈context〉 to check has to be specified as either bf or md. The command then chooses the 〈true code〉 or the 〈false code〉 based on where it is used (e.g., inside \textbf (or \bfseries) or not).
## Outlook
We issue the first prerelease now in the hope that you will help by making sure that all the enhancements and fixes inside are safe and without any undesired side effects, so please help with the testing if you can.
We expect further extensions (currently under development) to be added in a second prerelease, in particular a general hook management system for LaTeX, so stay tuned.
Enjoy — Frank
1. The internal version number for the pre-release is LaTeX2e <2020-10-01> pre-release-6, the earlier prereleases just mirrored the patch releases we did for 2020-02-02.
## 2020-05-27
### TUG
#### TUG 2020 conference: July 24-26, online via zoom
The TUG'20 conference will take place online via Zoom, from July 24-26, 2020. Registration is free of charge but requested in advance. We have posted the registration form and call for presentation proposals. We also need volunteers in several areas for the conference to be a success. Thanks, and hope to see you there!
## 2020-05-24
### Uwes kleines Technikblog - Kategorie LaTeX (by Uwe Ziegenhagen)
#### Beamer-Vorlage für (MINT)-Vorlesungen
Ich habe heute die erste Version einer Beamer-Vorlage für Vorlesungen auf github hochgeladen. Ziel war es, sowohl einzelne Module (Vorlesungen) als auch den kompletten Foliensatz erzeugen zu können. Die Vorlage eignet sich nicht nur für MINT-Veranstaltungen, mein Fokus lag aber auf dem sauberen Einbinden von Quellcodes, was bei geisteswissenschaftlichen Vorlesungen vielleicht nicht der Hauptfokus ist.
Die Dateien finden sich unter https://github.com/UweZiegenhagen/MINT-Lecture-Slide-Template
Pull Requests, Kommentare und Vorschläge werden gern gesehen.
Als nächstes baue ich noch Beispiele für die von mir definierten Befehle ein, die ein vereinfachtes Einbetten von Grafiken und Quellcodes erlauben.
### Uwe
Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.
üääüüöü–üöü–üöü–
## 2020-05-22
### LaTeX.net
#### goLaTeX Forum Updated
Auch auf Deutsch / in German: TeX.co
In April I did a pretty big software update on goLaTeX.de, and added more features since then.
What’s new? For example:
• The display is automatically adjusted, so it’s much better readable on smart phones. (before vs. now)
• Embedding images is easier
• More options for faster navigation
• Better protection agains spam (thanks to stopforumspam.com)
• Markdown support for easier input
For interested readers there’s a short description of the update procedure.
Thanks to DANTE for supporting the server operation!
Photo by Markus Winkler on Unsplash
## 2020-05-20
### LaTeX.net
#### DANTE
DANTE, “Deutschsprachige Anwendervereinigung TeX e.V.”, is a registered non-profit association of TeX users. It was founded April 14, 1989 in Heidelberg, Germany.
Its purpose is to support TeX and LaTeX mainly for German speaking people, by providing information, software, and support.
DANTE is an important supporter of the international TeX world too, such as by providing the central services for the Comprehensive TeX Archive Network, CTAN. Furthermore, it supports projects, such as font development, LaTeX development, user and developer meetings.
DANTE also supports web forums, FAQ sites, wikis, and further sites by covering the recurring server hosting costs since years. Thanks in the name of thousands registered users and countless anonymous LaTeX web surfers!
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http://www.mathworks.com/matlabcentral/fileexchange/25925-using-doxygen-with-matlab?requestedDomain=www.mathworks.com&nocookie=true | Highlights from Using Doxygen with Matlab
4.48148
4.5 | 30 ratings Rate this file 48 Downloads (last 30 days) File Size: 87.4 KB File ID: #25925 Version: 1.8
Using Doxygen with Matlab
by
Fabrice (view profile)
23 Nov 2009 (Updated )
Extracts automatically comments from your Matlab .m files using Doxygen to generate documentation
Editor's Notes:
This file was selected as MATLAB Central Pick of the Week
File Information
Description
This package allows you to extract automatically comments from your Matlab .m files using Doxygen to generate documentation.
This package provides :
- a perl script (m2cpp.pl) used to filter the .m files so that Doxygen can understand them
- a template for the Doxyfile file (configuration file for Doxygen) which has to be modified according to the location of your code
- documentationGuidelines.m, an .m file which describes how you should comment your code so that Doxygen can extract it and create nice documentation
- classDocumentationExample.m : an .m file describing possible comment for classes
- all the documentation (html format) automatically generated by Doxygen from the two .m files (see Doc/html/index.html), which provides informations about installation and how to write Doxygen comments.
Installation details :
- You need to have the Doxygen software installed (version 1.5.9 or newer required (tested with version 1.7.1))
- You need to have perl installed (perl is shipped with Matlab, located usually in $matlabroot\sys\perl\win32\bin) - unzip the DoxygenMatlab.zip to C:\DoxygenMatlbab (for example) - get the Doxyfile file from the C:\DoxygenMatlbab directory and replace the default Doxyfile provided by Doxygen - edit the Doxyfile file (or use the DoxyWizard tool provided by Doxygen) to modify a few settings : o EXTENSION_MAPPING=.m=C++ o FILTER_PATTERN=*m=C:\DoxygenMatlbab\m2cpp.pl o PERL_PATH=<path to your perl version> o INPUT=<directory where your documented code is located> o OUTPUT_DIRECTORY=<directory where you want to generate your documentation> o STRIP_FORM_PATH=<directory where your documented code is located> Note for Windows users : In certain circumstances, the association between .pl files and the perl executable is not well configured, leading to "Argument must contain filename -1 at C:\DoxygenMatlab\m2cpp.pl line 4" when running doxygen. To work around this issue, you should execute the following lines in a Windows command prompt ("cmd") : assoc .pl=PerlScript ftype PerlScript=C:\Program Files\MATLAB\R2010b\sys\perl\win32\bin\perl.exe %1 %* (don't forget to replace the path to the perl.exe file with yours in the line above) MATLAB release MATLAB 7.6 (R2008a) Other requirements - works with Matlab R2008a to R2010b - Doxygen 1.5.9 or newer required (tested with version 1.7.2) - perl required (usually shipped with Matlab) Tags for This File Please login to tag files. Please login to add a comment or rating. Comments and Ratings (72) 24 Jun 2016 Simone Gaiarin Simone Gaiarin (view profile) Since this code has not been updated since 2011, I've update this code to a github repository. I hope people will contribute to it in terms of code and documentation. Here is the code: https://github.com/simgunz/doxymatlab I'll try to include some of the patches proposed below. Comment only 09 Jun 2016 Thom DeCarlo Thom DeCarlo (view profile) Using this on OS X required a couple modifications. 1 - change "/usr/bin/perl.exe" to "/usr/bin/perl" 2 - run dos2unix on m2cpp.pl Also, as noted on 18 Nov 2010 by Guillaume JACQUENOT, function declarations with continued lines ("...\n") do not work properly. Otherwise, this script has been a great help! Comment only 10 Apr 2016 mmeyer89 mmeyer89 (view profile) Useful work, however it did not work well with namespaces. Here is my fix. 1. Add in the beginning of m2cpp following code # Extract namespace my$namespace = '';
foreach(split /\//, $fname) { if($_ =~ /^\+/) {
$namespace =$namespace.substr($_, 1).'.'; } } 2. Set$namespace as prefix to $className Example: Replace$classDef = "class ".$className.":public$classInheritance";
by
$classDef = "class ".$namespace.$className.":public$classInheritance";
The inherits are detected correctly and the list of classes is also grouped by namespace. I'm happy with the result.
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24 Mar 2016 Felipe Viana
Felipe Viana (view profile)
Great contribution. Thanks!!!
10 Oct 2015 Manpreet Dhimam
Manpreet Dhimam (view profile)
Hello,
I am generating a Doxygen documentaion for .m file.Firstly I generate it by simply editing the doxygen.conf file, I add FILE_PATTERNS= .m and EXTENSION_MAPPING= .m=c++. But it did not produce correct documentation of .m file. Now I am following your post "Using Doxygen with matlab and download "Doxygenmatlab" package. I have tried to understand all things, But unable to understand. Guide me what I have to do?
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17 Apr 2015 iamnotshaw
iamnotshaw (view profile)
possible typos in the instructions and doxyfile. should be FILTER_PATTERNS
otherwise doxygen ignoring the tag
30 Mar 2015 Ingo
Ingo (view profile)
Great file, using it since a long time.
However, now finally changed to Windows 7 I get the error/warning message warning: "Warning: Found ';' while parsing initializer list! (doxygen could be confused by a macro call without semicolon)" and my .m files are not parsed any longer. Do anybody know the workaround?! (Sonsoles earlier had the same problem but didn´t posted the solution;-()
12 Dec 2014 Simone Gaiarin
Simone Gaiarin (view profile)
This script is great!
It would be fantastic to have also a method to generate the source browser correctly with the comments stripped.
I've tried to strip the comments from the source files with a perl filter used in FILTER_SOURCE_FILES. But then the hyperlinks from the documentation to the code are wrong.
Any suggestion on how to do this?
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07 Mar 2014 Steven
Steven (view profile)
I realized that comment in the function is not possible to extract by this filter even with "%>"
And function output parameter does not reveal in the documents also, if using a "..." for line break in the function name, the filter cannot parse it correctly.
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27 Feb 2014 Steven
Steven (view profile)
Cool and thanks! I finally make it work. Keep stuck at the error "Argument must contain filename"
I fix it using this solution
http://stackoverflow.com/questions/4234581/argv-is-empty-using-activeperl-in-windows-7
Option1 does not fix it well, but option2 does the trick.
26 Jan 2014 Mark Mikofski
Mark Mikofski (view profile)
try sphinx with the matlabdomain
https://pypi.python.org/pypi/sphinxcontrib-matlabdomain
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Thank you for creating this Fabrice.
I will take a look at it and provide feedback.
18 Jun 2013 Eckard
Eckard (view profile)
Hello Fabrice.
My name is Eckard Klotz. I\'m the developer behind the two sourceforge projects:
Moritz : http://sourceforge.net/projects/moritz/
MuLanPa : http://sourceforge.net/projects/mulanpa/
Both are open source freeware-projects and should be used as an extension of Doxygen to create algorithm describing diagrams like nassi shneiderman or uml activity diagrams.
Today in both projects.
The snapshot of the project Moritz
http://sourceforge.net/projects/moritz/files/Snapshots/2013_05_27/
contains in the windows-distribution Moritz2_WIN32_2013_05_27.zip
in the folder LangPack\pascxal your filter. You will find in the file
The following paragraphs:
Since this distribution contains doxygen-configurations also and
with the version 1.9.08 the languages Matlab and Pascal are
supported also two third-party filters are added in the associated
LangPack folders:
Matlab:
Filter: m2cpp.pl
Author: Fabrice
Internet:
http://www.mathworks.com/matlabcentral/fileexchange/25925-using-doxygen-with-matlab
Pascal:
Filter: pas2dox.exe
Author: Darren Bowles
Internet: http://sourceforge.net/projects/pas2dox
I hope that this is OK for you but please don't hesitate to argue if you
Best regards,
Eckard Klotz.
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23 May 2013 Sonsoles
Sonsoles (view profile)
Now it is working in my matlab but i want to know if with this GraphViz options are available. i mean class graphs and caller graphs among others.
Thanks again
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22 May 2013 Jason
Jason (view profile)
I had to update m2cpp.pl for line endings on my Mac. In VIM, I used ":set ff=unix" and that did the trick.
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16 May 2013 Sonsoles
Sonsoles (view profile)
Hello!! i am runing Doxygen in my matlab code and the question is, it should show some graph as well.
i got the following errors:
C:/Users/Sonsoles/Documents/Fortran/Kompressorkoden/get_o_over_c.m:23: warning: Found ';' while parsing initializer list! (doxygen could be confused by a macro call without semicolon)
C:/Users/Sonsoles/Documents/Fortran/Kompressorkoden/get_omega_s.m:21: warning: Found ';' while parsing initializer list! (doxygen could be confused by a macro call without semicolon)
C:/Users/Sonsoles/Documents/Fortran/Kompressorkoden/Xfunc.m:21: warning: class for member M::::::calculate:' cannot be found.
thanks for the help
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21 Feb 2013 Aurelien Queffurust
Aurelien Queffurust (view profile)
I am under Windows XP R2011b. When I run Doxygen , the perl file m2cpp.pl shows up on the screen for each M-file that is processing. I have to close the file manually.
Moreover , your perl file requires to change all our syntax since the filter extracts only lines beginning with %>. For function description, same issue , we have to use a specific syntax.
The other submission "mtoc++ - Doxygen filter for Matlab and tools " is better , it doesn't require any change in our codes.
I definitely prefer m2html which is plug and play.
29 Jan 2013 Håkan Håkan
Håkan Håkan (view profile)
Hello Fabrice!
Finally - poh - I have m2cpp running in Windows 8 with Matlab 7.0.4!
First I had problems with access rights for involved programs, had to set Run as administrator, also had to patch in registry to make perl accept command line arguments.
Then m2cpp.pl crashed at row 43. After having modified by inserting
"use FileHandle;" at first row
and replaced row 43
"open(my $in,$my_fic);"
by
"
my $in = new FileHandle; # Fix for old version of Perl$in-> open($my_fic); " things run nicely!!! Thanks for your submission Håkan Fridén [email protected] Comment only 14 Jan 2013 Peter Peter (view profile) Question: Is this supposed to work for call graphs, like on M2HTML? The *inheritance* graphs are being generated properly. But I don't see any call graphs for any of my functions or class methods. Thanks 09 Jan 2013 Snowred Wang Snowred Wang (view profile) ok I just found out that I have to use the \fn keyword with the input name written exactly the same as what m2cpp generates. For example, I need to add a line saying %> \fn my_func_name(in par1,in par2) Thanks for m2cpp a very nice work! Comment only 08 Jan 2013 Snowred Wang Snowred Wang (view profile) I'm trying to use it with doxygenwizard 1.8.2 under windows 7. I believe that I've followed all instructions but I just got an empty index.html page. What might be the problem? Below are my logs Adding custom extension mapping: .m will be treated as language c++ Searching for include files... Searching for example files... Searching for images... Searching for dot files... Searching for msc files... Searching for files to exclude Searching for files to process... Searching for files in directory C:/Project/xxx Reading and parsing tag files Preprocessing C:/Project/xxx/xxx1.m... Parsing file C:/Project/xxx/xxx1.m... Preprocessing C:/Project/xxx/xxx2.m... Parsing file C:/Project/xxx/xxx2.m... Building group list... Building directory list... Building namespace list... Building file list... Building class list... Associating documentation with classes... Computing nesting relations for classes... Building example list... Searching for enumerations... Searching for documented typedefs... Searching for members imported via using declarations... Searching for included using directives... Searching for documented variables... Building member list... Searching for friends... Searching for documented defines... Computing class inheritance relations... Computing class usage relations... Flushing cached template relations that have become invalid... Creating members for template instances... Computing class relations... Add enum values to enums... Searching for member function documentation... Building page list... Search for main page... Computing page relations... Determining the scope of groups... Sorting lists... Freeing entry tree Determining which enums are documented Computing member relations... Building full member lists recursively... Adding members to member groups. Computing member references... Inheriting documentation... Generating disk names... Adding source references... Adding xrefitems... Sorting member lists... Computing dependencies between directories... Generating citations page... Counting data structures... Resolving user defined references... Finding anchors and sections in the documentation... Combining using relations... Adding members to index pages... Generating style sheet... Generating example documentation... Generating file sources... Generating file documentation... Generating page documentation... Generating group documentation... Generating class documentation... Generating namespace index... Generating graph info page... Generating directory documentation... Generating index page... Generating page index... Generating module index... Generating namespace index... Generating namespace member index... Generating annotated compound index... Generating alphabetical compound index... Generating hierarchical class index... Generating member index... Generating file index... Generating file member index... Generating example index... finalizing index lists... symbol cache used 16/65536 hits=192 misses=16 lookup cache used 0/65536 hits=0 misses=0 finished... When enabling GENERATE_HTMLHELP the search engine (SEARCHENGINE) should be disabled. I'll do it for you. *** Doxygen has finished 04 Dec 2012 Sebastian Pliefke Sebastian Pliefke (view profile) 04 Dec 2012 Sebastian Pliefke Sebastian Pliefke (view profile) Hi, I really like the doxygen integration and I'll use it from now on. Only a minor feature is missing from my point of view. I would like to comment on class variables after the definition and not before. Is that somehow possible or is there a quick fix to enable the tool for that? e.g. classdef CameraModel properties ImageSize = [640 480]; %> Camera image size in pixel [x y] end end Sorry I'm not really familiar with perl so that I couldn't do it by myself. Sebi 02 Nov 2012 Giovanni Giovanni (view profile) Actually someone helped me already to solve the problem. The file m2cpp.pl is formatted for DOS. One has to reformat it for Linux in order to get everything to work correctly (I did it with the tofrodos package). The program is great :-) 02 Nov 2012 Giovanni Giovanni (view profile) It *almost* works for me and I suspect it may have to do with a Linux problem. I receive the following error messages sh: /media/sda5/Giovanni/Utilities/Matlab_utilities/Matlab_exchange_downloads/DoxygenMatlab/m2cpp.pl: not found and the html files after this do nto contain any documentation (as no c++-style comments are produced). The m2cpp.pl is there, though, I have tried to move it around and I still receive corresponding error messages. Could anyone tell me where I have to start looking for solving this problem? Thanks in advance. Comment only 18 Sep 2012 Aguilar Aguilar (view profile) Great contribution, thanks a lot! 19 Dec 2011 Tom Tom (view profile) Dear Fabrice, is your package able to document code that uses the old class specification (before use of "classdef")? Thanks a lot, Tom Comment only 26 Oct 2011 Brian Brian (view profile) 27 Sep 2011 Eckard Eckard (view profile) Hello everyone I get an error by using the pearl-script like follows: Reading and parsing tag files Preprocessing D:/Daten/Projekt../src/fcn.m... Can't use an undefined value as filehandle reference at D:\Daten\Projekt\..\Filter\m2cpp.pl line 47 (formaly line 53). Parsing file D:/Daten/Projekt/../src/fcn.m... I tried to implent the patches from Bastian (07.07.2011) but the only the line-number changed from 43 to 47. I use the pearl-version of Matlab 2009b on windows XP-SP3 together with Doxygen version 1.7.4 Thanks for your help, Eckard Klotz. Comment only 09 Jul 2011 Bastien Bastien (view profile) Fabrice, thanks again for this wonderful script. It would be a nice improvement to have some options to be able to hide some information in the documentation: -> hide the Hidden methods/properties for the public APIs. -> hide the set.my_property/get.my_property methods in the classes that are useless in the documentation Comment only 07 Jul 2011 Bastien Bastien (view profile) Fabrice, I have solved the previous package problem modifying the PERL script m2cpp.pl: at line 42 (after the foreach$my_fic)
$packages = ""; if ($my_fic =~ /^[^\+]*\+(.*)[\/\\].*\.m/g){
$packages =$1.".";
$packages =~ s/[\/\\]\+/\./g; } at lines 176 and 180 (when defining$classDef:
replace: $classDef = "class ".$className
by: $classDef = "class ".$package.$className With this patch, your code will be compatible with the Matlab Packages! Comment only 07 Jul 2011 Bastien Bastien (view profile) Fabrice, thanks for this nice script. However, is it possible to include support for packages? For example, if you have: ./+PackageName/ClassName.m ./ChildClassName.m where ChildClassName < PackageName.ClassName, then the script combined with Doxygen will create 2 different pages for ClassName: - one for ClassName containing the definitions of all methods and properties - one for PackageName.ClassName containing no definition at all (just the inheritance relational graph) Maybe you could use C++ namespaces to solve this bug? (or maybe Java packages are more suited to implement nested packages like ./+Package1/+Package2/MyClass.m) thanks a lot in advance if you can help with this! PS: for those like Cedric who have some troubles with the "< handle" inheritance, you must UPDATE your Doxygen installation :-) 26 Apr 2011 Ian Ian (view profile) Wonderful interface to doxygen, very easy to implement. One very small niggle is the shebang at the top of the perl script in the latest update points to perl.exe -- this needs to be edited before it will work on *nix / OS X... 11 Apr 2011 LeFlaux LeFlaux (view profile) Fabrice, thank you for your quick response. The flag was already set to YES. However, in the meantime I realized that doxygen works for private directories located in standard folders but not in class folders: foo/private/stuff.m % works foo/@myclass/stuff.m % works foo/@myclass/private/stuff.m % won't appear in doxygen Regards 06 Apr 2011 Fabrice Fabrice (view profile) LeFlaux, I guess you problem is a Doxygen issue (maybe the EXTRACT_PRIVATE is set to NO in your Doxyfile). If not, could you send me a test case so that I can reproduce your problem ? Comment only 25 Mar 2011 LeFlaux LeFlaux (view profile) Dear Fabrice, thank you for this great and useful piece of software! Just one little question: I got directories named private' in my Matlab-project. The documentation of .m files contained in such directories are not displayed. Any suggestions? Comment only 23 Mar 2011 Vincent Vincent (view profile) The same problem (see the post of the 11 Mar 2011) happens when the attribute name begins with "end" (for instance "endDate"). Comment only 22 Mar 2011 guillaume guillaume (view profile) Thx a lot for this great tool ! 18 Mar 2011 Vincent Vincent (view profile) I experienced a little problem when using it on "@" folder class definition. As strange as it looks, when the name of my function (defined in an external .m file inside the @ folder) begins with a "m" letter, the function does not appear in the generated class description. It works just fine when I change it in another letter. Any idea? thanks Comment only 11 Mar 2011 Evgeny Pr Evgeny Pr (view profile) Hi Fabrice, I noticed a small problem. At multiple inheritance from a class from a package-directory the base class name is defined incorrectly. For example: +My - package-directory BaseClass.m - base class in +My directory SomeClass.m - some class in +My directory "SomeClass" define: classdef SomeClass < My.BaseClass end When you create a documentation obtained that SomeClass is inherited from the "My", a not from "My.BaseClass" or "BaseClass". :) Comment only 02 Mar 2011 Fabrice Fabrice (view profile) Hi Cedric, - the inheritance syntax (classdef MyClass < handle) is fully supported by the m2cpp.pl script : could you send me a test file so that I can see why you experienced such errors using this syntax ? - your second problem is an encoding configuration issue in your Doxyfile (you shouldn't use the UTF-8 encoding but probably the ISO8859-1 encoding) Regards, Fabrice Comment only 16 Feb 2011 Cedric Boudinet Cedric Boudinet (view profile) It seems good, however I do encounter some problems: one of my scripts is a classdef deriving from 'handle' : classdef MyClass < handle the parser gives an error since < is not closed by a > Is there a way to avoid this ? Another problem is that the parser gives errors on non-ascii letters (é, è, ...) Comment only 22 Jan 2011 Jack Jack (view profile) I've been using and enjoying your product. I have a quick question though. 1)I am using Matlab 2007a with only fuctions, i.e., not classes. I cannot get doxygen to create any graphs, either using graphviz or the included graphing library. I'm familiar with doxygen, and was wondering if your product in conjunction with doxygen supports graph generation via function calls alone? I uses a similiar perl script posted somewhere online to convert from .m to .c and it could generate graphs in doxygen. Thank you for your time, the .m is included below, in which no graph is generated (I have graph generation enabled in doxygen and all the setting in expert are correct aslwell I believe). %> @brief Brief description of the function %> %> More detailed description. %> %> \latexonly %>$\bigl(\begin{smallmatrix}
%> a&b\\ c&d
%> \end{smallmatrix} \bigr)$%> \endlatexonly %> %> @param arg1 First argument %> @param arg2 Second argument %> %> @retval out1 return value for the first output variable %> @retval out2 % ====================================================================== function [out1, out2] = hhh( arg1, arg2) out1 = arg2; out2 = arg1; c = fb(out1); end % ====================================================================== %> @brief Brief description of the function %> %> More detailed description. %> %> \latexonly %>$\bigl(\begin{smallmatrix}
%> a&b\\ c&d
%> \end{smallmatrix} \bigr)$%> \endlatexonly %> %> @param arg1 First argument %> %> @retval out1 return value for the first output variable % ====================================================================== function [out1] = fb( arg1) out1 = arg2; end 2) when I use /latexonly /endlatex only Doxygen commands to put in a matrix in latex, my matrices/equations have the "///" comment denoted for c++, this is not a problem, but if there is an easy fix I'll like to know. Comment only 11 Dec 2010 Mikhail Konnik Mikhail Konnik (view profile) Thanks for the update, Fabrice! Works perfect. Linux users may find my tweaked Doxyfile for this m2cpp.pl tool useful: http://mikhailkonnik.pbworks.com/w/file/matlab2doxygen.zip By the way, does anybody know how to add citations to the documentation from Doxygen using LaTeX? I mean, one have \cite commands in the documentation, and those cited sources should appear in the doxygen-generated docs. Any ideas? 08 Dec 2010 LeFlaux LeFlaux (view profile) Just awesome! :) Thank You very much for this tool! Note on m2cpp.pl: Linux users should change the first line to #!/usr/bin/perl 18 Nov 2010 Guillaume JACQUENOT Guillaume JACQUENOT (view profile) This seems a good function. I notice a small bug When I declare a function on several lines, the different arguments are not recognized For example, something like this will produce warning, and won't be correctly displayed %> @param AAAAAA %> @param BBBBBBBB %> @param CCCC %> @param DDDDDDDD %> @param EEEEEEEEEE %> %> @retval Res return value for the first output variable %> @retval RTex return value for the second output variable function [Res,RTex] = Compute_residual(AAAAAA,BBBBBBBB,... CCCC,... DDDDDDDD,... EEEEEEEEEE) 12 Nov 2010 Fabrice Fabrice (view profile) I have just updated the m2cpp.pl script to better support : - @-folder class definition - multiple class inheritance (classdef a < b & c) - classes attributes (Sealed, Hidden,...) - events (transformed into enum Events in the generated documentation) - private / protected / pubic methods - private / protected / pubic properties - constant properties (with their initialization) - abstract classes (transformed into virtual functions in the generated documentation) - the ignored argument (~) in function declaration is now read and transformed into an ignoredArg in the generated documentation Comment only 10 Nov 2010 Evgeny Pr Evgeny Pr (view profile) Fabrice, please, update your files on fileexchange. Last version works fine! Comment only 09 Nov 2010 Simon Prince Simon Prince (view profile) Great utility, thanks. Question about using it with multiple-file classes - I get it to work with a class in a single file, but when I set up a class in an @folder, I don't seem to get the function based methods (in separate files) located within my doxygen derived class. 26 Oct 2010 green_fr green_fr (view profile) Another strange point with inheritance. Imagine class Father inherited by two classes Son1 and Son2. In Father there is a method Father::doIt() overloaded by Son1::doIt(), but inherited directly from Father by Son2. The strange point is that in Son2 documentation you’ll see comments about Father::doIt() (that is normal) followed by «Reimplemented in Son1» (that is weird — or may be this is a standard C++ documentation agreement ?) Comment only 26 Oct 2010 green_fr green_fr (view profile) I mean, with a brief form of abstract methods. With the following example : methods (Abstract) function calcPMInitiale(obj) end projection(obj, iteration) end The first method will be detected, but not the second (correct definition for MatLab). Comment only 26 Oct 2010 green_fr green_fr (view profile) But I think it doesn't work properly with abstract methods... Comment only 26 Oct 2010 green_fr green_fr (view profile) 24 Oct 2010 Evgeny Pr Evgeny Pr (view profile) A small correction to define classes (classdef (Hidden, Sealed) SomeClass) are handled correctly: if (/(^\s*classdef)\s*(\s*$$[\w,\s]+\s*$$)?\s*([\w\d_]+)\s*<?\s*([\w\d_]+)?(.*)/) Comment only 24 Oct 2010 Evgeny Pr Evgeny Pr (view profile) I think the problem with this line in the file "m2cpp pl": if (/(^\s*classdef)\s*(\s*$$Enumeration\s*$$)?\s*([\w\d_]+)\s*<?\s*([\w\d_]+)?(.*)/) "Enumeration" is undocumented attribute? I've corrected as follows: if (/(^\s*classdef)\s*(\s*$$[\w]+\s*$$)?\s*([\w\d_]+)\s*<?\s*([\w\d_]+)?(.*)/) and added the else condition: ... else {$className = $3;$classDef = "class ".$className.":public$4";
}
This works, but I think it is not quite correct.
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23 Oct 2010 Evgeny Pr
Evgeny Pr (view profile)
Hello!
I've found a bug.
Define a class with attributes:
classdef (Hidden) SomeClass < handle
end
...or with any other class attribute.
Such a definition is Parsed incorrectly.
Fabrice, You could fix this bug?
I don't understand anything in Perl. :)
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21 Oct 2010 Evgeny Pr
Evgeny Pr (view profile)
Hello!
Do not use Perl, which comes with Matlab! It does not work correctly. Use ActivePerl.
12 Oct 2010 Erik Gudmundson
Erik Gudmundson (view profile)
Thank you, Fabrice, for a really nice tool! It seems, as Felix has noted, that only classes contained in one single .m-file are supported, and not the folder (@-)structure. Furthermore, the private class-properties are displayed as public ones. Is there any chance that you could fix this? I'm aware that the Matlab style of Access, SetAccess, and GetAccess might be tricky, but it would be really helpful. Thanks a lot!
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29 Sep 2010 Mike
Mike (view profile)
Does this tool handle collaboration diagrams? When a class is composed using another class, it does not show up in the collaboration diagram. The collaboration diagram is always the same as the class diagram. Am I doing something wrong?
17 Sep 2010 Felix
Felix (view profile)
Thank you very much for this great tool.
Could it be that class hierarchies are not properly detected when the classes are in a package?
13 Aug 2010 Matt McDonnell
Matt McDonnell (view profile)
Fabrice,
Thanks for looking in to this, changing the extension from m to .m fixed the problem with 1.7.1.
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04 Aug 2010 Fabrice
Fabrice (view profile)
Matt,
I tried to use Doxygen 1.7.1 and I suppose I reproduced your problem.
I guess this is a Doxygen bug, but as a workaround, you could try to change the value of EXTENSION_MAPPING in the Doxyfile :
EXTENSION_MAPPING=.m=C++ (don't forget the dot before the 'm').
Could you tell me if it solved your problem ?
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30 Jul 2010 Matt McDonnell
Matt McDonnell (view profile)
Very nice tool - many thanks!
I found I had to use Doxygen 1.6.1, not 1.7.1 (latest).
I see from http://stackoverflow.com/questions/2701671/problem-with-input-filter-using-doxygen-1-6-3-on-windows-xp
you've seen something similar before.
21 May 2010 Fabrice
Fabrice (view profile)
Ed,
I changed the m2cpp.pl file so that unix users can use it.
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21 May 2010 Ed
Ed (view profile)
I had a problem using the script under Unix (Linux) since the first line of the perl script, which defines the interpreter to use (/usr/bin/perl), was terminated using a carriage-return (\r) instead of a line feed (\n). Because of this the perl interpreter could not be found. Since the first line only makes sense in a Unix environment, I think the line-ending character for the first line (at least) should be changed to a line-feed.
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07 May 2010 Fabrice
Fabrice (view profile)
Mike, you can comment only variables outside function block (this is a Doxygen limitation), that is :
- arguments passed to functions, for example :
%> @brief Description of the foo function
%> @param a this is a description of var a
%> @param b this is a description of var b
function foo(a, b)
...
end
- properties in a classdef definition, for example :
classdef foo
properties
%> this is a description of the var a
a
%> this is a description of the var b
b
..
end
...
end
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06 May 2010 Mikhail Konnik
Mikhail Konnik (view profile)
Fabrice, thank for the program!
The only question I have: is it possible to comment variables by such script? I mean, if I have
a = [1,2,3,4]; %> this is a description of the var
can it be displayed in doxygen-generated docs?
02 May 2010 Fabrice
Fabrice (view profile)
Lien-Chi,
Maybe your perl exe is not properly installed (it seems it is the case for the perl provided by Matlab). You could try the following workarounds :
1. Set the following variables in the Doxyfile :
INPUT_FILTER=perl m2cpp.pl
FILE_PATTERNS=*.m
2. If it doesn't work you should try to install ActivePerl : with this version of perl, everything is working fine.
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30 Apr 2010 Lien-Chi
Lien-Chi (view profile)
Why I got the following message? "Argument must contain filename -1 at C:\Users\user\Desktop\DoxygenMatlab\m2cpp.pl line 4"
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30 Mar 2010 Joydeep
Joydeep (view profile)
Nice! Would be useful if it can also generate enum classes by handling something like this,
classdef(Enumeration) Color < int32
enumeration
Red(0)
Green(1)
Yellow(2)
end
end
30 Mar 2010 Joydeep
Joydeep (view profile)
03 Feb 2010 Raymond
Raymond (view profile)
This is exactly what I was looking for, and to see that it works on subfunctions and object oriented code is simply brilliant. This is a wonderful replacement to mtoc that works wonderfully. Many kudos to the author for simplifying my life and increasing my productivity. Brilliant!
14 Nov 2010 1.5
* @-folder for classes
* multiple inheritance
* class attributes
* private / protected / public properties and methods
* abstract methods
* constant properties
* events
* ignored arguments (~)
06 Apr 2011 1.8
Fixed a few bugs :
- property names (and method names) beginning with end are now allowed (as pointed out by Vincent)
- inheritance with classes containing a dot is now supported (as pointed out by Evgeni Pr) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.714809775352478, "perplexity": 9405.901778962829}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218186774.43/warc/CC-MAIN-20170322212946-00415-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://crypto.stackexchange.com/questions/70881/gentry-halevi-s-fully-homomorphic-encryption-and-hermite-factor | # Gentry-Halevi’s Fully-Homomorphic Encryption and hermite factor
In section 7.2, page 18 in Chen-Nguyen paper regarding BKZ 2.0, they point out different Hermite factors related to Gentry-Halevi FHE.
More precisely, it is said that the critical Hermite factor for the "large" challenge with lattice dimension $$n=32768$$ is $$\delta = 1.0081^n$$.
How is this Hermite factor computed ?
• I think it has the following meaning. Each column corresponds to a specific challenge of Gentry-Halevi’s main challenges. You have to find the specific challenge (the links of the challenges are dead) and then calculate $||{\bf b}_1||/vol(L)^{1/n}.$ Then write it in the form $\delta^{n}.$ This form is useful, because many experiments have been made with different algorithms, and for the specific challenge, BKZ-130 (experimentally) outputs a basis with $\delta^n$ Hermite factor. – 111 Sep 21 '19 at 23:06
$$Root Hermite Factor=( B[0].norm() / ( L.volume() )^{(1/i)})^{(1/i)}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 3, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7672616839408875, "perplexity": 1315.115531868028}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703506640.22/warc/CC-MAIN-20210116104719-20210116134719-00796.warc.gz"} |
http://www.edcottrell.com/2010/07/20/from-the-shack-to-the-courthouse/?shared=email&msg=fail | # From The Shack to the Courthouse
Since I’ve mentioned the popular novel The Shack in a number of posts, it seems worthwhile to mention the latest real-life twist in the novel’s story. According to the LA Times, The Shack‘s author, William Paul Young, has sued pastors Wayne Jacobsen and Brad Cummings; the start-up the three created to publish the book initially, Windblown Media; and the book’s current publisher, Hachette. Young alleges that he is owed $8 million in royalties through December 2008, as well as other relief. Windblown has counterclaimed for$5 million. Meanwhile, Jacobsen and Cummings have filed an amended copyright filing with the Library of Congress.
I will refrain from commenting on the legal issues (or the legal posture of these cases, which is more than a little muddled in the article), but am posting this merely for general interest.
h/t: Tim Challies | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2203332483768463, "perplexity": 7087.121439841973}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698542932.99/warc/CC-MAIN-20161202170902-00028-ip-10-31-129-80.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/51725/when-trying-to-calculate-arc-length-what-is-the-easiest-way-to-approach-the-d | # When trying to calculate arc length, what is the easiest way to approach the $(dy/dx)^2$ portion?
When trying to calculate arc length, what is the easiest way to approach the $(dy/dx)^2$ portion?
If I have: $$x = \frac{1}{3}\sqrt{y}(y-3),\qquad 1\leq y\leq 9;$$
I take the derivative of the function and get $\frac{1}{2}y^{1/2} - \frac{1}{2}y^{-1/2}$.
Next I have to square the derivative and I got $$\frac{1}{4}y^{1/4} + \frac{1}{2} + \frac{1}{4}y^{-1}$$ after adding the 1 from the formula (for arc length) to it.
Now to condense everything into the formula up to that point I would have:
$$L = \int_1^9 \sqrt{ \frac{1}{4}y^{1/4} + \frac{1}{2} + \frac{1}{4}y^{-1}}$$
Now in order to get rid of that radical I would have to get some sort of perfect square but the trouble is sometimes it's difficult to see it right away, and I don't really see it in this one. Is there a better way to go about these problems other than just "looking" at it and trying to figure it out?a
-
As far as I can tell, you've (i) computed the derivative incorrectly; and you've (ii) squared incorrectly. – Arturo Magidin Jul 16 '11 at 3:43
@Arturo - I checked both parts against the solutions manual and they are correct. Actually I lied. Only the derivative is correct. Edit: Ok yeah I'm dumb, I squared incorrectly and I think that threw the problem off for me the rest of the way. I'll try it again. – Ryan Jul 16 '11 at 3:48
@Ryan: Yes, what is the square of $y^{1/2}$? And after you get it right, note that adding $1$ just changes the sign of the middle term. Does this suggest what your new expression might be the square of? – André Nicolas Jul 16 '11 at 3:53
@Ryan: I posted an answer assuming there is a typo in the title and in the first sentence. Instead of $dy/dx$ should be $dx/dy$, and that you want to evaluate $$\int_{1}^{9}\sqrt{1+\left( \frac{dx}{dy}\right) ^{2}}dy$$, because the derivative $dy/dx$ and the corresponding integral would become too complicated. – Américo Tavares Jul 16 '11 at 14:34
@Ryan: I was about to leave when I typed the comment, so I was wrong about (i). I had misinterpreted your original function, and realized the mistake when I edited the question; only to then be too rushed to fix the comment. Sorry if I misdirected you on that score. – Arturo Magidin Jul 17 '11 at 3:56
Updated. I assume there is a typo in the title and in the first sentence of the question, as I commented, and that you want to evaluate $\displaystyle\int_{1}^{9}\sqrt{1+\left( \dfrac{dx}{dy}\right) ^{2}}\mathrm{d}y$, where $x=\dfrac{1}{3}\sqrt{y}\left( y-3\right)$. Its derivative is
$$\dfrac{\mathrm{d}x}{\mathrm{d}y}=\dfrac{1}{2}y^{1/2}-\dfrac{1}{2}y^{-1/2}.$$
So
$$\left( \frac{1}{2}y^{1/2}-\frac{1}{2}y^{-1/2}\right) ^{2}=\frac{1}{4}y-% \frac{1}{2}+\frac{1}{4}y^{-1},$$
and
$$1+\left( \frac{1}{2}y^{1/2}-\frac{1}{2}y^{-1/2}\right) ^{2}=\frac{1}{4}y+% \frac{1}{2}+\frac{1}{4}y^{-1}.$$
Now in order to get rid of that radical I would have to get some sort of perfect square but the trouble is sometimes it's difficult to see it right away, and I don't really see it in this one. Is there a better way to go about these problems other than just "looking" at it and trying to figure it out?
Hint:
$$\frac{1}{4}y+\frac{1}{2}+\frac{1}{4}y^{-1}=\frac{1}{4}\frac{\left( y+1\right) ^{2}}{y},$$
or use the completing the square technique.
Note: most of the times inside the radical you have a function $f(y)$ which is not a perfect square nor anything similar. What you get as integrand is a radical $R(y)=\sqrt{f(y)}$. And you have to integrate it using the normal integration techniques: substitution or by parts. But it is not guaranteed that the integral has a closed form. However, in the present case you do obtain a closed form.
-
As I comented above this answer assumes there is a typo in the title and in the first sentence of the question. Instead of $dy/dx$ should be $dx/dy$, and OP wants to evaluate $$\int_{1}^{9}\sqrt{1+\left( \frac{dx}{dy}\right) ^{2}}dy,$$ because the derivative $dy/dx$ and the corresponding integral would become too complicated. – Américo Tavares Jul 16 '11 at 14:36 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9562870860099792, "perplexity": 116.43596105783237}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-27/segments/1435375098987.83/warc/CC-MAIN-20150627031818-00275-ip-10-179-60-89.ec2.internal.warc.gz"} |
http://tex.stackexchange.com/questions/9921/font-sabon-into-texworks | # Font “Sabon” into TeXworks
What has to be done to include a new font such as Sabon into TeXworks? I already have the necessary files, however, ´cause I´m a beginner with LaTex, I can´t manage to bring the files into TeXworks. Somebody able and interested to help me?
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Your question is a kind of category error: TeXWorks is a front end to a TeX Distribution, so there is no coherent way to "bring the files into TeXWorks" (since I'm assuming that you don't simply want to type your source files in Sabon within TeXWorks.) Are you asking about how to create LaTeX documents using the Sabon font? – Alan Munn Jan 31 '11 at 0:19
I'm assuming what Alan says in his note is right, and that you want to create documents using Sabon, not somehow use Sabon in TeXworks' GUI.
The easiest way then, is probably to use XeLaTeX. First, makse sure Sabon is installed and is accessible to other programs. Add the following to your LaTeX preamble:
``````\usepackage{fontspec}
\defaultfontfeatures{Mapping=tex-text}
\setmainfont{Sabon} % Or it might need to be \setmainfont{Sabon LT Std} or something
``````
To build your document, choose "XeLaTeX" from TeXworks's dropdown box.
Now, Sabon should be the main font of the document. For more information, see the fontspec package documentation.
- | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9581984281539917, "perplexity": 3823.1452477070206}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500815756.79/warc/CC-MAIN-20140820021335-00361-ip-10-180-136-8.ec2.internal.warc.gz"} |
http://prof.msoltys.com/?p=3252 | # Paper with Ryan McIntyre to appear in the Journal of Discrete Algorithms
Happy to announce that Ryan McIntyre’s masters thesis results, An improved upper bound and algorithm for clique covers (prelim), will be published as our joint paper in Journal of Discrete Algorithms.
Our paper is on indeterminate strings, which are important for their applicability in bioinformatics. (They have been considered, for example, in Christodoulakis 2015 and Helling 2017.)
An interesting feature of indeterminate strings is the natural correspondence with undirected graphs. One aspect of this correspondence is the fact that the minimal alphabet size of indeterminates representing any given undirected graph corresponds to the size of the minimal clique cover of this graph. This paper first considers a related problem proposed in Helling 2017: characterize \$latex\Theta_n(m)\$, which is the size of the largest possible minimal clique cover (i.e., an exact upper bound), and hence alphabet size of the corresponding indeterminate, of any graph on $n$ vertices and $m$ edges. We provide improvements to the known upper bound for $\Theta_n(m)$. Helling 2017 also presents an algorithm which finds clique covers in polynomial time. We build on this result with an original heuristic for vertex sorting which significantly improves their algorithm’s results, particularly in dense graphs.
This work was the result of building on Helling 2017 (see this post) and of a year of research undertaken by Ryan McIntyre under my (Michael Soltys) supervision at the California State University Channel Islands. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 6, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6784643530845642, "perplexity": 1429.931251029418}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371803248.90/warc/CC-MAIN-20200407152449-20200407182949-00195.warc.gz"} |
https://scholars.hkbu.edu.hk/en/publications/shrinkage-based-diagonal-hotellings-tests-for-high-dimensional-sm-2 | # Shrinkage-based diagonal Hotelling's tests for high-dimensional small sample size data
Kai Dong, Herbert Pang, Tiejun TONG*, Marc G. Genton
*Corresponding author for this work
Research output: Contribution to journalArticlepeer-review
11 Citations (Scopus)
## Abstract
High-throughput expression profiling techniques bring novel tools and also statistical challenges to genetic research. In addition to detecting differentially expressed genes, testing the significance of gene sets or pathway analysis has been recognized as an equally important problem. Owing to the "large p small n" paradigm, the traditional Hotelling's T2 test suffers from the singularity problem and therefore is not valid in this setting. In this paper, we propose a shrinkage-based diagonal Hotelling's test for both one-sample and two-sample cases. We also suggest several different ways to derive the approximate null distribution under different scenarios of p and n for our proposed shrinkage-based test. Simulation studies show that the proposed method performs comparably to existing competitors when n is moderate or large, but it is better when n is small. In addition, we analyze four gene expression data sets and they demonstrate the advantage of our proposed shrinkage-based diagonal Hotelling's test.
Original language English 127-142 16 Journal of Multivariate Analysis 143 https://doi.org/10.1016/j.jmva.2015.08.022 Published - 1 Jan 2016
## Scopus Subject Areas
• Statistics and Probability
• Numerical Analysis
• Statistics, Probability and Uncertainty
## User-Defined Keywords
• Diagonal Hotelling's test
• High-dimensional data
• Microarray data
• Null distribution
• Optimal variance estimation
## Fingerprint
Dive into the research topics of 'Shrinkage-based diagonal Hotelling's tests for high-dimensional small sample size data'. Together they form a unique fingerprint. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8291404843330383, "perplexity": 4701.935057344736}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585120.89/warc/CC-MAIN-20211017021554-20211017051554-00106.warc.gz"} |
http://mathhelpforum.com/trigonometry/229909-demonstration-envolving-complex-numbers-help-please.html | 1. Demonstration envolving Complex numbers!! Help please
Please someone help me.. I've an exam in 2 days ... The following problem makes me nuts.. I can't get it right..
Show that:
cos(∏ - alpha) + i cos (∏/2 - alpha)
-------------------------------------------- = cis (∏ - 2alpha)
cis (alpha)
I'm desperate... I've tried everything I know.. any help is appreciated
2. Re: Demonstration envolving Complex numbers!! Help please
Originally Posted by josepbigorra
Please someone help me.. I've an exam in 2 days ... The following problem makes me nuts.. I can't get it right..
Show that:
cos(∏ - alpha) + i cos (∏/2 - alpha)
-------------------------------------------- = cis (∏ - 2alpha)
cis (alpha)
I'm desperate... I've tried everything I know.. any help is appreciated
What have you tried? It's hard to give you advice when we don't know what you've tried.
I'd favor expanding out $cos( \pi - \alpha ) = cos(\pi)~cos(\alpha) + sin(\pi)~sin(\alpha) = -cos(\alpha)$ etc.
-Dan
3. Re: Demonstration envolving Complex numbers!! Help please
What I've tried is the following:
$cos (\pi- \alpha ) = - cos (\alpha )$
$i cos (\frac{\pi }{2} - \alpha ) = isin (\alpha )$
Then i proceed to the substitution in the expression from above, but I don't know how to continue.
4. Re: Demonstration envolving Complex numbers!! Help please
Originally Posted by topsquark
What have you tried? It's hard to give you advice when we don't know what you've tried.
I'd favor expanding out $cos( \pi - \alpha ) = cos(\pi)~cos(\alpha) + sin(\pi)~sin(\alpha) = -cos(\alpha)$ etc.
-Dan
What I've tried is the following:
Then i proceed to the substitution in the expression from above, but I don't know how to continue.
5. Re: Demonstration envolving Complex numbers!! Help please
Okay, you've got the $cos( \pi - \alpha )$ and $sin( \pi / 2 - \alpha )$ expressions. So you need to evaluate:
$\frac{-cos( \alpha ) + i ~sin( \alpha ) }{cos( \alpha ) + i~sin(\alpha)}$
You could do the division but recall Euler's theorem: $cos(x) + i~sin(x) = e^{ix}$. See what you can do with this.
-Dan
6. Re: Demonstration envolving Complex numbers!! Help please
Or "rationalize the denominator" by multiplying numerator and denominator by the conjugate of the denominator:
$\left(\frac{-cos(\alpha)+ isin(\alpha)}{cos(\alpha)+ isin(\alpha)}\right)\left(\frac{cos(\alpha)- isin(\alpha)}{cos(\alpha)- isin(\alpha)}\right)$
$= -cos^2(\alpha)+ sin^2(\alpha)+ 2sin(\alpha)cos(\alpha)$.
Now, what about that left side? $cis(\pi- 2\alpha)= cos(\pi- 2\alpha)+ isin(\pi- 2\alpha)= -cos(2\alpha)+ isin(2\alpha)$
So what are $cos(2\alpha)$ and $sin(2\alpha)$?
7. Re: Demonstration envolving Complex numbers!! Help please
Originally Posted by HallsofIvy
Or "rationalize the denominator" by multiplying numerator and denominator by the conjugate of the denominator:
$\left(\frac{-cos(\alpha)+ isin(\alpha)}{cos(\alpha)+ isin(\alpha)}\right)\left(\frac{cos(\alpha)- isin(\alpha)}{cos(\alpha)- isin(\alpha)}\right)$
$= -cos^2(\alpha)+ sin^2(\alpha)+ 2sin(\alpha)cos(\alpha)$.
Now, what about that left side? $cis(\pi- 2\alpha)= cos(\pi- 2\alpha)+ isin(\pi- 2\alpha)= -cos(2\alpha)+ isin(2\alpha)$
So what are $cos(2\alpha)$ and $sin(2\alpha)$?
My friend thanks a lot for the info... I managed to get the problem working.. I really appreciate your help | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 18, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9195080399513245, "perplexity": 2832.955256133005}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891814311.76/warc/CC-MAIN-20180223015726-20180223035726-00273.warc.gz"} |
https://plausibilitytheory.wordpress.com/2013/09/03/cricket-mythbusting-not-outs-and-averages/ | ## Cricket Mythbusting: Not-Outs and Averages
The usual batting average is defined as the total number of runs scored by a batsman (both out and not-out) divided by the number of outs (total number of completed innings). Under this definition, it is possible that players who often end the innings not out may get inflated batting averages.
Really!? I’d have hoped researchers would know better. This is a popular myth about batting averages that is not just wrong but actually the opposite of the truth. Getting a lot of not outs deflates your average. I will attempt to explain why without getting too technical.
It is well known that batters “get their eye in”. When first at the crease, batting is more difficult, and once the batter gets used to the conditions (the pitch, the bowler, their technique, etc) they get better. This is not just folklore, the effect can be detected in data. If a batter is currently fresh at the crease (i.e. they are on a low score), they are less good than if they have been batting for a while.
Consider two batters. Batter 1 scores $\{40, 12, 72, 6, 38, 0\}$. Batter 2 scores $\{5^*, 13^*, 11^*, 0, 4, 12^*, 3, 17^*, 10, 3^*, 12^*, 1^*, 5, 0^*, 61, 11\}$. Both batters scored 168 runs and were dismissed 6 times, for an average of 28. But who is better? Well, it looks like Batter 1 had three fairly good innings (40, 72, and 38) where they were able to get their eye in. But Batter 2 only had one innings where they scored above 20. Batter 2 scored their runs in more difficult circumstances, while not “warmed up”. Yet they still performed as well as Batter 1. Therefore, Batter 2 is probably better.
Another way to think of this is to imagine that you are on 5 not out (say). If you were able to complete your innings, how many extra runs would you score? Since you now have your eye in a little bit, the expected amount of extra runs is greater than your actual batting average. Not outs deflate your average because they rob you of the opportunity to score an additional amount of runs that is greater than your average, because you already have your eye in.
I am a senior lecturer in the Department of Statistics at The University of Auckland. Any opinions expressed here are mine and are not endorsed by my employer.
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### 5 Responses to Cricket Mythbusting: Not-Outs and Averages
1. Matt says:
I think the perception probably occurs because lower order batsmen and bowlers do have (I think) inflated averages, so that’s assumed to be the cause. I think the real cause is facing tired bowling and older balls and having generally more attacking fields. Take the recent Ashses series and look at Australia’s batting averages over the series http://stats.espncricinfo.com/the-ashes-2013/engine/records/averages/batting_bowling_by_team.html?id=7362;team=2;type=series. Pattinson had the 5th best average and Starc the 8th, better than Warner, Haddin and Khawaja. Both Pattinson and Starc appear to benefit from 2 NOs, but I think more significantly, were batting at the end of innings against tired bowlers and old balls and batting to fields that were set to try and get them out quickly rather than saving boundaries. If Pattinson and Starc batted in the middle order they would not have such high averages, and its not because they wouldn’t have those NOs.
As far as the game goes though, a run is a run, which is why I’ve always thought that bowling alrounders are hugely valuable (and a better bet than batting allrounders, like Watson). England looked a much better side with Bresnan at 8 than they did once he was injured.
2. “I think the perception probably occurs because lower order batsmen and bowlers do have (I think) inflated averages, so that’s assumed to be the cause. I think the real cause is facing tired bowling and older balls and having generally more attacking fields.”
That seems very plausible.
• Daz Voz says:
Similarly, we may assumed openers have _deflated_ averages.
I wonder whether there is any statistically significant difference between the average at number 1 and average at number 2.
3. Nico says:
I certainly agree with what you are getting at but I don’t like your scenario – in the six completed innings both batsman had wasn’t batsman one able to better fight through his challenging period to get his eye in and then score more? The fact batter two had another nine not outs just represent him getting more opportunity than player one and with that opportunity he bumped his average up by 12 runs.
4. Nico says:
In the short format cricket I think batsman should not be rewarded for a not out when that not out comes because the team is out of deliveries to face. Personally I would move to something like what Andrew suggested but also measure the number of not outs and volume of runs in those not outs in run chases. Those are the really valuable not outs but they get the same status as a player who finishes not out in a 100 run loss! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 2, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5681889653205872, "perplexity": 2471.1880497909083}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187822488.34/warc/CC-MAIN-20171017200905-20171017220905-00264.warc.gz"} |
https://worldwidescience.org/topicpages/a/adsorbed+organic+films.html | #### Sample records for adsorbed organic films
1. Computer simulations of adsorbed liquid crystal films
Science.gov (United States)
Wall, Greg D.; Cleaver, Douglas J.
2003-01-01
The structures adopted by adsorbed thin films of Gay-Berne particles in the presence of a coexisting vapour phase are investigated by molecular dynamics simulation. The films are adsorbed at a flat substrate which favours planar anchoring, whereas the nematic-vapour interface favours normal alignment. On cooling, a system with a high molecule-substrate interaction strength exhibits substrate-induced planar orientational ordering and considerable stratification is observed in the density profiles. In contrast, a system with weak molecule-substrate coupling adopts a director orientation orthogonal to the substrate plane, owing to the increased influence of the nematic-vapour interface. There are significant differences between the structures adopted at the two interfaces, in contrast with the predictions of density functional treatments of such systems.
2. Hydrophobic Porous Material Adsorbs Small Organic Molecules
Science.gov (United States)
Sharma, Pramod K.; Hickey, Gregory S.
1994-01-01
Composite molecular-sieve material has pore structure designed specifically for preferential adsorption of organic molecules for sizes ranging from 3 to 6 angstrom. Design based on principle that contaminant molecules become strongly bound to surface of adsorbent when size of contaminant molecules is nearly same as that of pores in adsorbent. Material used to remove small organic contaminant molecules from vacuum systems or from enclosed gaseous environments like closed-loop life-support systems.
3. Size selective hydrophobic adsorbent for organic molecules
Science.gov (United States)
Sharma, Pramod K. (Inventor); Hickey, Gregory S. (Inventor)
1997-01-01
The present invention relates to an adsorbent formed by the pyrolysis of a hydrophobic silica with a pore size greater than 5 .ANG., such as SILICALITE.TM., with a molecular sieving polymer precursor such as polyfurfuryl alcohol, polyacrylonitrile, polyvinylidene chloride, phenol-formaldehyde resin, polyvinylidene difluoride and mixtures thereof. Polyfurfuryl alcohol is the most preferred. The adsorbent produced by the pyrolysis has a silicon to carbon mole ratio of between about 10:1 and 1:3, and preferably about 2:1 to 1:2, most preferably 1:1. The pyrolysis is performed as a ramped temperature program between about 100.degree. and 800.degree. C., and preferably between about 100.degree. and 600.degree. C. The present invention also relates to a method for selectively adsorbing organic molecules having a molecular size (mean molecular diameter) of between about 3 and 6 .ANG. comprising contacting a vapor containing the small organic molecules to be adsorbed with the adsorbent composition of the present invention.
4. Interactions of organic contaminants with mineral-adsorbed surfactants
Science.gov (United States)
Zhu, L.; Chen, B.; Tao, S.; Chiou, C.T.
2003-01-01
Sorption of organic contaminants (phenol, p-nitrophenol, and naphthalene) to natural solids (soils and bentonite) with and without myristylpyridinium bromide (MPB) cationic surfactant was studied to provide novel insight to interactions of contaminants with the mineral-adsorbed surfactant. Contaminant sorption coefficients with mineral-adsorbed surfactants, Kss, show a strong dependence on surfactant loading in the solid. At low surfactant levels, the Kss values increased with increasing sorbed surfactant mass, reached a maximum, and then decreased with increasing surfactant loading. The Kss values for contaminants were always higher than respective partition coefficients with surfactant micelles (Kmc) and natural organic matter (Koc). At examined MPB concentrations in water the three organic contaminants showed little solubility enhancement by MPB. At low sorbed-surfactant levels, the resulting mineral-adsorbed surfactant via the cation-exchange process appears to form a thin organic film, which effectively "adsorbs" the contaminants, resulting in very high Kss values. At high surfactant levels, the sorbed surfactant on minerals appears to form a bulklike medium that behaves essentially as a partition phase (rather than an adsorptive surface), with the resulting Kss being significantly decreased and less dependent on the MPB loading. The results provide a reference to the use of surfactants for remediation of contaminated soils/sediments or groundwater in engineered surfactant-enhanced washing.
5. Structure and properties of water film adsorbed on mica surfaces
Science.gov (United States)
Zhao, Gutian; Tan, Qiyan; Xiang, Li; Cai, Di; Zeng, Hongbo; Yi, Hong; Ni, Zhonghua; Chen, Yunfei
2015-09-01
The structure profiles and physical properties of the adsorbed water film on a mica surface under conditions with different degrees of relative humidity are investigated by a surface force apparatus. The first layer of the adsorbed water film shows ice-like properties, including a lattice constant similar with ice crystal, a high bearing capacity that can support normal pressure as high as 4 MPa, a creep behavior under the action of even a small normal load, and a character of hydrogen bond. Adjacent to the first layer of the adsorbed water film, the water molecules in the outer layer are liquid-like that can flow freely under the action of external loads. Experimental results demonstrate that the adsorbed water layer makes the mica surface change from hydrophilic to weak hydrophobic. The weak hydrophobic surface may induce the latter adsorbed water molecules to form water islands on a mica sheet.
6. Ordered molecular layer structure of lubricating oil adsorbed films
Institute of Scientific and Technical Information of China (English)
2001-01-01
Low-angle X-ray diffraction has been applied to analyze the structure of stearic acid LB films and self-grown surface adsorbed films of aluminium product metalworking lubricants. The results show that LB films exhibit a good layer-like ordered structure in the normal direction of film-carrying surface, while in the tangential direction, they do not show a cyclically ordered molecular arrangement; as for the self-grown surface adsorbed films of aluminium sheet and strip metalworking lubricants, their molecules are orderly arranged to certain degree in both the tangential and the normal directions of film-carrying surface, and they have a short-range ordered structure. Moreover, the better the orientation of normal molecules is, the higher the oil film strength is, and the smaller the friction factor is.
7. Alpha spectrometry sample preparation using selectively adsorbing thin films
International Nuclear Information System (INIS)
Several years ago, Switzerland introduced limits for natural radionuclides in food, e.g. 1 Bq/l for 226Ra or 10 Bq/l for the sum of 238U and 234U in drinking water. To make enforcement by regional (cantonal) laboratories more attractive, simplified analytical methods had to be offered, at least for drinking water. A first step has been the development of radium adsorbing sheets. A 20 mm x 20 mm MnO2 film on a polyamide substrate adsorbs more than 80% of the radium present in a 100 ml water sample within 6 h. The film is thin enough to allow for high resolution alpha spectrometry. A second step now under way is to produce thin films, which selectively adsorb uranium. Actually, an ion exchange resin with diphosphonic and sulfonic acid groups is used for this purpose. Although not yet very thin, these films make possible energy resolutions far better than with any liquid scintillation alpha spectrometry method. Adsorption efficiencies are more than 80% after 20 h exposition to a 100 ml water sample (20 mm x 20 mm sheet). A third step is to have a system that measures radionuclide concentrations in water on-line. A prototype is presented where radionuclides are adsorbed on a film in contact with the water. A Si-detector placed on the other side of the film support counts the alphas passing through
8. Adsorbed Methane Film Properties in Nanoporous Carbon Monoliths
Science.gov (United States)
Soo, Yuchoong; Chada, Nagaraju; Beckner, Matthew; Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter
2013-03-01
Carbon briquetting can increase methane storage capacity by reducing the useless void volume resulting in a better packing density. It is a robust and efficient space-filling form for an adsorbed natural gas vehicle storage tank. To optimize methane storage capacity, we studied three fabrication process parameters: carbon-to-binder ratio, compaction temperature, and pyrolysis temperature. We found that carbon-to-binder ratio and pyrolysis temperature both have large influences on monolith uptakes. We have been able to optimize these parameters for high methane storage. All monolith uptakes (up to 260 bar) were measured by a custom-built, volumetric, reservoir-type instrument. The saturated film density and the film thickness was determined using linear extrapolation on the high pressure excess adsorption isotherms. The saturated film density was also determined using the monolayer Ono-Kondo model. Film densities ranged from ca. 0.32 g/cm3 - 0.37 g/cm3.The Ono-Kondo model also determines the binding energy of methane. Binding energies were also determined from isosteric heats calculated from the Clausius-Clapeyron equation and compared with the Ono-Kondo model method. Binding energies from Ono-Kondo were ca. 7.8 kJ/mol - 10 kJ/mol. Work funded by California Energy Commission Contract #500-08-022.
9. Preconcentration in gas or liquid phases using adsorbent thin films
Directory of Open Access Journals (Sweden)
Antonio Pereira Nascimento Filho
2006-03-01
Full Text Available The possibility of preconcentration on microchannels for organic compounds in gas or liquid phases was evaluated. Microstructures with different geometries were mechanically machined using poly(methyl methacrylate - PMMA as substrates and some cavities were covered with cellulose. The surfaces of the microchannels were modified by plasma deposition of hydrophilic or hydrophobic films using 2-propanol and hexamethyldisilazane (HMDS, respectively. Double layers of HMDS + 2-propanol were also used. Adsorption characterization was made by Quartz Crystal Measurements (QCM technique using reactants in a large polarity range that showed the adsorption ability of the structures depends more on the films used than on the capillary phenomena. Cellulose modified by double layer film showed a high retention capacity for all gaseous compounds tested. However, structures without plasma deposition showed low retention capacity. Microchannels modified with double layers or 2-propanol plasma films showed higher retention than non-modified ones on gas or liquid phase.
10. Aging of the nanosized photochromic WO3 films and the role of adsorbed water in the photochromism
Science.gov (United States)
Gavrilyuk, A. I.
2016-02-01
Here it has been reported on aging of the nanosized WO3 film, which is revealed is continuous reduction of the photochromic sensitivity over time. Water molecules physically adsorbed on the film surface from ambient air form donor-acceptor and hydrogen bonds, changing gradually the adsorption state to chemisorption which prevents an access of organic molecules that serve as hydrogen donors by the photochromism. The mechanism of the process has been investigated and discussed. The role of water in the photochromism has been highlighted. The difference in the efficiency for being of a hydrogen donor in the photochromic process between water and organic molecules is discussed.
11. Organic adsorbates on metal surfaces. PTCDA and NTCDA on AG(110)
Energy Technology Data Exchange (ETDEWEB)
Abbasi, Afshin
2010-02-22
Polyaromatic molecules functionalized with carboxylic groups have served as model systems for the growth of organic semiconducting films on a large variety of substrates. Most non-reactive substrates allow for a growth mode compatible with the bulk phase of the molecular crystal with two molecules in the unit cell, but some more reactive substrates including Ag(111) and Ag(110) can induce substantial changes in the first monolayer (ML). In the specific case of Ag(110), the adsorbate unit cell of both NTCDA and PTCDA resembles a brickwall structure, with a single molecule in the unit cell. From this finding, it can be concluded that the adsorbate-substrate interaction is stronger than typical inter-molecular binding energies in the respective bulk phases. In the present work, the interactions between small Ag(110) clusters and a single NTCDA or PTCDA molecule are investigated with different ab initio techniques. Four major ingredients contribute to the binding between adsorbate and substrate: Directional bonds between Ag atoms in the topmost layer and the oxygen atoms of the molecule, Pauli repulsion between filled orbitals of molecule and substrate, an attractive van-der-Waals interaction, and a negative net charge on the molecule inducing positive image charges in the substrate, resulting therefore in an attractive Coulomb interaction between these opposite charges. As both Hartree-Fock theory and density functional theory with typical gradient-corrected density functional do not contain any long range correlation energy required for dispersion interactions, we compare these approaches with the fastest numerical technique where the leading term of the van-der-Waals interaction is included, i.e. second order Moeller-Plesset theory (MP2). Both Hartree-Fock and density functional theory result in bended optimized geometries where the adsorbate is interacting mainly via the oxygen atoms, with the core of the molecule repelled from the substrate. Only at the MP2 level
12. Interactions between adsorbed macromolecules : measurements on emulsions and liquid films
NARCIS (Netherlands)
Vliet, van T.
1977-01-01
The aim of this study was to gain more insight into the factors, determining the inter- and intramolecular interactions between adsorbed macromolecules. To that end several experimental and theoretical approaches were followed, using well-defined systems. It was shown that these interactions could c
13. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films
International Nuclear Information System (INIS)
Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of 4He adsorbed on metallic films. In contrast to measurements of 4He adsorbed on all other insulating substrates, we have shown that 4He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, 4He adsorbed on sapphire and on Ag films and H2 adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs
14. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films
Energy Technology Data Exchange (ETDEWEB)
Kenny, T.W.
1989-05-01
Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of /sup 4/He adsorbed on metallic films. In contrast to measurements of /sup 4/He adsorbed on all other insulating substrates, we have shown that /sup 4/He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, /sup 4/He adsorbed on sapphire and on Ag films and H/sub 2/ adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs.
15. Preparation and characterization of a novel adsorbent for removing lipophilic organic from water
Institute of Scientific and Technical Information of China (English)
LIU; Huijuan; DAI; Ruihua; QU; Jiuhui; RU; Jia
2005-01-01
A novel composite adsorbent containing a kind of lipid-triolein is studied. The adsorbent is prepared by embedding triolein into cellulose acetate (CA) sphere. The preparation method, the physical-chemical properties of the adsorbent and the removal efficiency of two organochlorinated pesticides are studied. The adsorbent is stable in water and no triolein leaks into water for 465 h soaking. The adsorbent has high adsorption capacity for organochlorinated pesticides such as dieldrin and aldrin. The results suggest that triolein-containing adsorbent could serve as a good adsorbent for lipophilic organic pollutants. The adsorption rate for lipophilic pollutants is very fast and has relation with the logKow of the compounds.
16. Critical behavior of superfluid 4He films adsorbed in aerogel glass
International Nuclear Information System (INIS)
We present measurements of the superfluid density and heat capacity of thin films of 4He adsorbed in aerogel glass. We find that the critical behavior of the superfluid density for films with transition temperatures between 50 mK and 1 K is similar to that seen for films adsorbed on Vycor. Power-law behavior is observed over at least one order of magnitude in reduced temperature with an exponent ζ=0.63±0.03. This exponent is much smaller than the value 0.811±0.004 found when the pores were filled with helium. We also find that the exponent is unchanged by the addition of small amounts of 3He. These results are consistent with the existence of a correlation length that diverges at the superfluid transition. Unlike for full-pore 4He aerogel, the correlation length is long compared with all structural length scales throughout the superfluid density power-law regime, thus leading to the more bulklike critical behavior. The heat capacity of 4He films in aerogel shows no singularity like that seen for full-pore 4He aerogel or for thin films adsorbed in Vycor. We show that this result is consistent with the predictions of hyperuniversality given the long correlation lengths implied by the superfluid density measurements
17. Luminescence of 2,5-bis(2-benzoxazolylhydroquinone Molecules Adsorbed on Copper Island Film
Directory of Open Access Journals (Sweden)
Chayka K.
2005-12-01
Full Text Available Characteristics of photoluminescence spectra of polycrystalline 2,5-bis(2-benzoxazolylhydroquinone (BBHQ adsorbed on a copper island film have been studied in the conditions of laser excitation. The reflectivity, transmission and luminescence spectra have been measured in the temperature range of 600 – 800 K for a number of film thicknesses and annealing conditions. It has been found that annealing of the films induces changes in the islands’ morphologies. The spectral luminescence characteristics have been compared with those peculiar for the BBHQ solution in 3-metylpentan, for the BBHQ samples adsorbed on pure plane-parallel quartz plates and for the samples contained in quartz glass cell. The results have been used for interpretation of the spectra and estimation of the average amplification factor and the characteristics of molecular excitons in the crystals under investigation.
18. Anomalous conformational transitions in cytochrome C adsorbing to Langmuir-Blodgett films
Science.gov (United States)
Sankaranarayanan, Kamatchi; Nair, B. U.; Dhathathreyan, A.
2013-05-01
Helix to beta conformational transitions in proteins has attracted much attention due to their relevance to fibril formation which is implicated in many neurological diseases. This study reports on unusual conformational transition of cytochrome C adsorbing to hydrophilic surface containing pure cationic lipid and mixed Langmuir-Blodgett films (LB films) of cationic and neutral lipids. Evidence for conformational changes of the protein from its native helical state to beta sheet comes from Circular dichroic spectroscopy (CD spectroscopy). Analysis of these samples using High resolution TEM (HRTEM) shows a typical fibrillar pattern with each strand spacing of about 0.41 nm across which can be attributed to the repeat distance of interdigitated neighboring hydrogen-bonded ribbons in a beta sheet. Changes in contact angles of protein adsorbing to the LB films together with the increased mass uptake of water using quartz crystal microbalance (QCM) confirm the role of positive charges in the conformational transition. Dehydration of the protein resulting from the excess water entrainment in the polar planes of the cationic lipid in hydrophilic surface seems to trigger the refolding of the protein to beta sheet while it retains its native conformation in hydrophobic films. The results suggest that drastic conformational changes in CytC adsorbing to cationic lipids may be of significance in its role as a peripheral membrane protein.
19. Unusual Morphologies of Poly(vinyl alcohol) Thin Films Adsorbed on Poly(dimethylsiloxane) Substrates.
Science.gov (United States)
Karki, Akchheta; Nguyen, Lien; Sharma, Bhanushee; Yan, Yan; Chen, Wei
2016-04-01
Adsorption of poly(vinyl alcohol) (PVOH), 99% and 88% hydrolyzed poly(vinyl acetate), to poly(dimethylsiloxane) (PDMS) substrates was studied. The substrates were prepared by covalently attaching linear PDMS polymers of 2, 9, 17, 49, and 116 kDa onto silicon wafers. As the PDMS molecular weight/thickness increases, the adsorbed PVOH thin films progressively transition from continuous to discontinuous morphologies, including honeycomb and fractal/droplet. The structures are the result of thin film dewetting that occurs upon exposure to air. The PVOH film thickness does not vary significantly on these PDMS substrates, implicating the PDMS thickness as the cause for the morphology differences. The adsorbed PVOH thin films are less stable and have a stronger tendency to dewet on thicker, more liquid-like PDMS layers. When PVOH(99%) and PVOH(88%) thin films are compared, fractal and droplet morphologies are observed on high molecular weight PDMS substrates, respectively. The formation of the unique fractal features in the PVOH(99%) thin films as well as other crystalline and semicrystalline thin films is most likely driven by crystallization during the dehydration process in a diffusion-limited aggregation fashion. The only significant enhancement in hydrophilicity via PVOH adsorption was obtained on PDMS(2k), which is completely covered with a PVOH thin film. To mimic the lower receding contact angle and less liquid-like character of the PDMS(2k) substrate, light plasma treatment of the higher molecular weight PDMS substrates was carried out. On the treated PDMS substrates, the adsorbed PVOH thin films are in the more continuous honeycomb morphology, giving rise to significantly enhanced wettability. Furthermore, hydrophobic recovery of the hydrophilized PDMS substrates was not observed during a 1 week period. Thus, light plasma oxidation and subsequent PVOH adsorption can be utilized as a means to effectively hydrophilize conventional PDMS substrates. This study
20. Film morphology and orientation of amino silicone adsorbed onto cellulose substrate
International Nuclear Information System (INIS)
A series of amino silicones with different amino values were synthesized and adsorbed onto surfaces of cotton fibers and cellulose substrates. The film morphology, hydrophobic properties and surface composition of the silicones are investigated and characterized by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), contact angle measurement, X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance infrared (ATR-IR). The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton fibers and cellulose substrates and reduce the surface roughness significantly. Furthermore, the roughness becomes smaller with an increase in the amino value. All these results suggest that the orientation of amino silicone molecule is with the amino functional groups of amino silicone molecule adsorbed onto the cellulose interface while the main polymer chains and the hydrophobic Si-CH3 groups extend toward the air.
1. Competition between the superfluidity and the slippage of 4He films adsorbed on porous gold
International Nuclear Information System (INIS)
We have carried out QCM measurements for 4He films adsorbed on porous gold in the crossover region between the superfluidity and slippage. In relative low areal densities, the resonance frequency increases gradually below TS due to the slippage of solid film, while the superfluid onset is observed in high areal densities. In the crossover region, we observed a peculiar behavior: The increase in the resonance frequency below TS is suddenly suppressed at a certain temperature TD. From these observations, it is concluded that the superfluidity and the slippage of 4He competes with each other.
2. Comparative study of normal and branched alkane monolayer films adsorbed on a solid surface. I. Structure
DEFF Research Database (Denmark)
Enevoldsen, Ann Dorrit; Hansen, Flemming Yssing; Diama, A.;
2007-01-01
) tetracosane film is roughly the same as the bulk melting point, the surface strongly stabilizes the 2D squalane film such that its melting point is 91 K above its value in bulk. Therefore, squalane, like tetracosane, will be a poor lubricant in those nanoscale devices that require a fluid lubricant at room......The structure of a monolayer film of the branched alkane squalane (C30H62) adsorbed on graphite has been studied by neutron diffraction and molecular dynamics (MD) simulations and compared with a similar study of the n-alkane tetracosane (n-C24H52). Both molecules have 24 carbon atoms along their...... backbone and squalane has, in addition, six methyl side groups. Upon adsorption, there are significant differences as well as similarities in the behavior of these molecular films. Both molecules form ordered structures at low temperatures; however, while the melting point of the two-dimensional (2D...
3. Scandium-Triflate/Metal-Organic Frameworks: Remarkable Adsorbents for Desulfurization and Denitrogenation.
Science.gov (United States)
Khan, Nazmul Abedin; Jhung, Sung Hwa
2015-12-01
Scandium-triflate (Sc(OTf)3) was introduced for the first time on metal-organic frameworks (MOFs), to utilize acidic Sc(OTf)3 for adsorptive desulfurization and denitrogenation of fuel containing benzothiophene (BT), dibenzothiophene (DBT), quinoline (QUI), and indole (IND). A remarkable improvement in the adsorption capacity (about 65% based on the weight of adsorbents; 90% based on the surface area of the adsorbents) was observed with the Sc(OTf)3/MOFs as compared to the virgin MOFs for the adsorption of BT from liquid fuel. The basic QUI was also adsorbed preferentially onto the acidic Sc(OTf)3/MOFs. However, nonsupported Sc(OTf)3 showed negligible adsorption capacities. The improved adsorptive performance for BT, DBT, and QUI might be derived from acid-base interactions between the acidic Sc(OTf)3 and basic adsorbates. On the other hand, the Sc(OTf)3, loaded on MOFs, reduced the adsorption capacity for neutral IND due to lack of interaction between the neutral adsorbate and acidic adsorbent and the reduced porosities of the modified adsorbents. The reusability of the adsorbents was found satisfactory up to the fourth run. On the basis of the result, it is suggested that metal-triflates, such as Sc(OTf)3, can be prospective materials for adsorptive desulfurization/denitrogenation of fuels when supported on porous materials such as MOFs. PMID:26575418
4. Metallo-organic decomposition films
Science.gov (United States)
Gallagher, B. D.
1985-01-01
A summary of metallo-organic deposition (MOD) films for solar cells was presented. The MOD materials are metal ions compounded with organic radicals. The technology is evolving quickly for solar cell metallization. Silver compounds, especially silver neodecanoate, were developed which can be applied by thick-film screening, ink-jet printing, spin-on, spray, or dip methods. Some of the advantages of MOD are: high uniform metal content, lower firing temperatures, decomposition without leaving a carbon deposit or toxic materials, and a film that is stable under ambient conditions. Molecular design criteria were explained along with compounds formulated to date, and the accompanying reactions for these compounds. Phase stability and the other experimental and analytic results of MOD films were presented.
5. Heat capacity of quantum adsorbates: Hydrogen and helium on evaporated gold films
International Nuclear Information System (INIS)
The author has constructed an apparatus to make specific heat measurements of quantum gases adsorbed on metallic films at temperatures between 0.3 and 4 K. He has used this apparatus to study quench-condensed hydrogen films between 4 and 923 layers thick with J = 1 concentrations between 0.28 and 0.75 deposited on an evaporated gold surface. He has observed that the orientational ordering of the J = 1 molecules depends on the substrate temperature during deposition of the hydrogen film. He has inferred that the density of the films condensed at the lowest temperatures is 25% higher than in bulk H2 crystals and have observed that the structure of those films is affected by annealing at 3.4 K. The author has measured the J = 1 to J = 0 conversion rate to be comparable to that of the bulk for thick films; however, he found evidence that the gold surface catalyzes conversion in the first two to four layers. He has also used this apparatus to study films of 4He less than one layer thick adsorbed on an evaporated gold surface. He shows that the phase diagram of the system is similar to that for 4He/graphite although not as rich in structure, and the phase boundaries occur at different coverages and temperatures. At coverages below about half a layer and at sufficiently high temperatures, the 4He behaves like a two-dimensional noninteracting Bose gas. At lower temperatures and higher coverages, liquidlike and solidlike behavior is observed. The Appendix shows measurements of the far-infrared absorptivity of the high-Tc superconductor La1.87Sr0.13CuO4
6. A novel aminated polymeric adsorbent for removing refractory dissolved organic matter from landfill leachate treatment plant
Institute of Scientific and Technical Information of China (English)
ZHANG Long; LI Aimin; WANG Jinnan; LU Yufei; ZHOU Youdong
2009-01-01
Refractory dissolved organic matter (DOM) from landfill leachate treatment plant was with high dissolved organic carbon (DOC) content.An aminated polymeric adsorbent NDA-8 with tertiary amino groups and sufficient mesopore was synthesized, which exhibited high adsorption capacity to the DOM (raw water after coagulation).Resin NDA-8 performed better in the uptake of the DOM than resin DAX-8 and A100.Electrostatic attraction was considered as the decisive interaction between the adsorbent and adsorbate.Special attention was paid to the correlation between porous structure and adsorption capacity.The mesopore of NDA-8 played a crucial role during uptake of the DOM.In general, resin in chloride form performed a higher removal rate of DOC.According to the column adsorption test, total adsorption capacity of NDA-8 was calculated to 52.28 mg DOC/mL wet resin.0.2 mol/L sodium hydroxide solution could regenerate the adsorbent efficiently.
7. Extra adsorption and adsorbate superlattice formation in metal-organic frameworks
Science.gov (United States)
Sung Cho, Hae; Deng, Hexiang; Miyasaka, Keiichi; Dong, Zhiyue; Cho, Minhyung; Neimark, Alexander V.; Ku Kang, Jeung; Yaghi, Omar M.; Terasaki, Osamu
2015-11-01
Metal-organic frameworks (MOFs) have a high internal surface area and widely tunable composition, which make them useful for applications involving adsorption, such as hydrogen, methane or carbon dioxide storage. The selectivity and uptake capacity of the adsorption process are determined by interactions involving the adsorbates and their porous host materials. But, although the interactions of adsorbate molecules with the internal MOF surface and also amongst themselves within individual pores have been extensively studied, adsorbate-adsorbate interactions across pore walls have not been explored. Here we show that local strain in the MOF, induced by pore filling, can give rise to collective and long-range adsorbate-adsorbate interactions and the formation of adsorbate superlattices that extend beyond an original MOF unit cell. Specifically, we use in situ small-angle X-ray scattering to track and map the distribution and ordering of adsorbate molecules in five members of the mesoporous MOF-74 series along entire adsorption-desorption isotherms. We find in all cases that the capillary condensation that fills the pores gives rise to the formation of ‘extra adsorption domains’—that is, domains spanning several neighbouring pores, which have a higher adsorbate density than non-domain pores. In the case of one MOF, IRMOF-74-V-hex, these domains form a superlattice structure that is difficult to reconcile with the prevailing view of pore-filling as a stochastic process. The visualization of the adsorption process provided by our data, with clear evidence for initial adsorbate aggregation in distinct domains and ordering before an even distribution is finally reached, should help to improve our understanding of this process and may thereby improve our ability to exploit it practically.
8. Organic photovoltaic films
Directory of Open Access Journals (Sweden)
Jenny Nelson
2002-05-01
The last two years have seen an unprecedented growth of interest in solar cells made from organic electronic materials. This is partly due to the rapid growth of the photovoltaic market1, which has stimulated research into longer term, more innovative photovoltaic technologies, and partly to the development of organic electronic materials for display applications. The rapid progress in optoelectronic molecular materials has introduced a range of potential new photovoltaic materials, as well as an improved understanding of the capabilities of such materials and confidence in their application2.
9. Effect of γ-ray irradiation on adsorbents used in organic waste treatment
International Nuclear Information System (INIS)
Radioactive organic liquids (ROLs) are waste that require specific treatment. The Arvia process, developed by Arvia Technology Ltd., combines adsorption of organic material with electrochemical oxidation. This work focuses on the effect of γ-rays on the performance of adsorbents used in the Arvia process. Adsorbents used in this experimental study were provided by Arvia Technology Ltd. Specifically, Nyex 1000, a flake like carbon-based adsorbent, and Nyex 2105, a carbon-based adsorbent with a granular morphology. The γ-ray irradiation experiments were carried out using a Co-60 irradiator. The impact of irradiation on the microstructure, the adsorption capacity and the leaching of the 2 adsorbents were studied. The results show that no significant changes were detected in terms of structure, adsorption capacity and leaching of ions. The results of this paper are promising for the use of Nyex 1000 and Nyex 2105 as adsorbents in electrochemical waste treatment processes which involve high levels of γ-rays. The article is followed by the slides of the presentation
10. Photoconductivity of thin organic films
International Nuclear Information System (INIS)
Thin organic films were deposited on silicon oxide surfaces with golden interdigitated electrodes (interelectrode gap was 2 μm), and the film resistivities were measured in dark and under white light illumination. The compounds selected for the measurements include molecules widely used in solar cell applications, such as polythiophene (PHT), fullerene (C60), pyrelene tetracarboxylic diimide (PTCDI) and copper phthalocyanine (CuPc), as well as molecules potentially interesting for photovoltaic applications, e.g. porphyrin-fullerene dyads. The films were deposited using thermal evaporation (e.g. for C60 and CuPc films), spin coating for PHT, and Langmuir-Schaeffer for the layer-by-layer deposition of porphyrin-fullerene dyads. The most conducting materials in the series are films of PHT and CuPc with resistivities 1.2 x 103 Ω m and 3 x 104 Ω m, respectively. Under light illumination resistivity of all films decreases, with the strongest light effect observed for PTCDI, for which resistivity decreases by 100 times, from 3.2 x 108 Ω m in dark to 3.1 x 106 Ω m under the light.
11. Economic alpha spectrometry using silicon microsystems and selectively adsorbing thin films
International Nuclear Information System (INIS)
We present first results obtained with a monitor SARAD EQF 3020 containing three alpha detector microsystems measuring radon in air, attached radon daughters and unattached radon daughters respectively. The three components are measured quasicontinuousely with a temporal resolution of 2 hours. The measuring range is 1 to 10 MBq/m3 by low detection limit of 0.1 Bq/m3 equivalent radon concentration. The system was rested in buildings, caves, mines, waterworks and other places. Using silicon microsystem integrating on a few chips an alpha detector, an ADC, a memory and logics can be produced at far lower cost than if assembled from individual components. We have also developed thin films selectively adsorbing radium and uranium from aqueous solutions, e.g. drinking waters. These films have simply to be placed into the solution to be analyzed and accumulate radium and uranium with a high efficiency. The adsorption capacity of this films is by a 20 h exposure nearly 70% for radium in the solution. The films are eventually measured by alpha spectrometry and show energy resolutions of below 50 keV. These thin films considerably reduce preparation times and thus costs. Replacing in addition the conventional alpha spectrometer by one of our silicon microsystems leads to a very economic system for the analysis of radium and uranium in drinking water. (author). 6 refs, 6 figs
12. The onset of superfluidity in thin films of 4He adsorbed on ordered and disordered substrates
International Nuclear Information System (INIS)
The authors have completed a systematic study of the superfluid density of 4He films adsorbed on two substrates: exfoliated basal-plane graphite and 91% porosity aerogel glass. The authors measurements demonstrate a dramatic difference in the coverage-dependence of the superfluid density in these two systems. The onset of superfluidity in the aerogel system is similar to that observed in the case of other disordered substrates such as Vycor glass and mylar. The superfluid density at zero temperature is nearly proportional to coverage once the critical coverage for superfluidity is exceeded. The superfluid density for films adsorbed on graphite does not evolve in this simple fashion. The onset of superfluidity appears to occur near two layers, but the superfluid density increases very rapidly between 2.5 and 3 layers. This coverage regime is also characterized by a dramatic sharpening density and transition temperature remain essentially unchanged as the coverage is increased. We will discuss in the context of recent theoretical work on the onset of superfluidity in model Bose systems
13. Nanotribological properties of water films adsorbing atop, and absorbing below, graphene layers supported by metal substrates
Science.gov (United States)
Liu, Zijian; Curtis, C. K.; Stine, R.; Sheehan, P.; Krim, J.
The tribological properties of graphite, a common lubricant with known sensitivity to the presence of water, have been studied extensively at the macroscopic and microscopic scales. Although far less attention has been devoted to the tribological properties of graphene, it has been established that the tribological response to the presence of water is dissimilar from that of graphite. We report here a quartz crystal microbalance study of the nanotribological properties of water films adsorbed/absorbed on graphene layers prepared by either chemical decomposition on nickel(111) substrates or transfer of freestanding graphene layers to aluminum substrates. Sliding friction levels of the water films were also measured for metal surfaces in the absence of a graphene layer. We observe very high friction levels for water adsorbed atop graphene on Ni(111) and very low levels for water on aluminum. For the case of graphene/aluminum, the data indicate that the water is absorbing between the graphene layer and the aluminum. Dissipation levels moreover indicate the presence of an interstitial water increases sliding friction between the graphene and the aluminum substrate Work supported by NSF and NRL.
14. Organic thin-film photovoltaics
OpenAIRE
Liu, Miaoyin
2010-01-01
Zusammenfassung Zur Verbesserung der Leistungsumwandlung in organischen Solarzellen sind neue Materialien von zentraler Bedeutung, die sämtliche Erfordernisse für organische Photovoltaik-Elemente erfüllen. In der vorliegenden Arbeit „Organic thin-film photovoltaics“ wurden im Hinblick auf ein besseres Verständnis der Zusammenhänge zwischen molekularer Struktur und der Leistungsfähigkeit neue Materialien in „bulk-heterojunction“ Solarzellen und in Festphasen-Farbstoffsensibilisierten ...
15. Comparative study of normal and branched alkane monolayer films adsorbed on a solid surface. II. Dynamics
DEFF Research Database (Denmark)
Enevoldsen, Ann Dorrit; Hansen, Flemming Yssing; Diama, A.;
2007-01-01
The dynamics of monolayer films of the n-alkane tetracosane (n-C24H52) and the branched alkane squalane (C30H62) adsorbed on graphite have been studied by quasielastic and inelastic neutron scattering and molecular dynamics (MD) simulations. Both molecules have 24 carbon atoms along their carbon...... backbone, and squalane has an additional six methyl side groups symmetrically placed along its length. The authors' principal objective has been to determine the influence of the side groups on the dynamics of the squalane monolayer and thereby assess its potential as a nanoscale lubricant. To investigate...... analysis of the quasielastic scattering. They conclude that there are no major differences in the monolayer dynamics caused by intramolecular branching. It remains to be seen whether this similarity in monolayer dynamics also holds for the lubricating properties of these molecules in confined geometries...
16. Low cost adsorbents for the removal of organic pollutants from wastewater.
Science.gov (United States)
Ali, Imran; Asim, Mohd; Khan, Tabrez A
2012-12-30
Water pollution due to organic contaminants is a serious issue because of acute toxicities and carcinogenic nature of the pollutants. Among various water treatment methods, adsorption is supposed as the best one due to its inexpensiveness, universal nature and ease of operation. Many waste materials used include fruit wastes, coconut shell, scrap tyres, bark and other tannin-rich materials, sawdust and other wood type materials, rice husk, petroleum wastes, fertilizer wastes, fly ash, sugar industry wastes blast furnace slag, chitosan and seafood processing wastes, seaweed and algae, peat moss, clays, red mud, zeolites, sediment and soil, ore minerals etc. These adsorbents have been found to remove various organic pollutants ranging from 80 to 99.9%. The present article describes the conversion of waste products into effective adsorbents and their application for water treatment. The possible mechanism of adsorption on these adsorbents has also been included in this article. Besides, attempts have been made to discuss the future perspectives of low cost adsorbents in water treatment. PMID:23023039
17. Relaxation of surface stress induced by an organic adsorbate: PTCDA on vicinal Ag(111)
Energy Technology Data Exchange (ETDEWEB)
Pollinger, Florian; Vrdoljak, Pavo; Fertig, Dominik; Schmitt, Stefan; Kumpf, Christian; Schoell, Achim; Umbach, Eberhard [Universitaet Wuerzburg, Experimentelle Physik II, Am Hubland, 97074 Wuerzburg (Germany); Tian, Zhen; Sander, Dirk; Kirschner, Juergen [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany)
2007-07-01
Self-organization of metallic surfaces on large scales can be induced by the adsorption of organic molecules and has been observed in several experiments. One example is the growth of 3,4,9,10-perylenetetracarboxylic-acid dianhydride (PTCDA) on stepped (8.5 -vicinal) Ag(111) surfaces. At elevated temperatures, the adsorbate molecules lead to a bunching of substrate steps, which agglomerate to facets of critical sizes. The facets arrange in a coverage-dependent grating-like pattern on a mesoscopic length scale. The resulting order requires a long-range interaction which is mediated by the substrate. It can be explained by a change of surface stress induced by the adsorbate layer. Experimentally, such a change is directly accessible by an optical cantilever bending technique. We monitored the bending of a faceting thin Ag(10 8 7) crystal with this method in order to quantify the occurring relaxation of surface stress.
18. Direct Measurement of Adsorbed Gas Redistribution in Metal–Organic Frameworks
Energy Technology Data Exchange (ETDEWEB)
Chen, Ying-Pin [Texas A & M Univ., College Station, TX (United States); Liu, Yangyang [Texas A & M Univ., College Station, TX (United States); Liu, Dahuan [Texas A & M Univ., College Station, TX (United States); Beijing Univ. of Chemical Technology (China); Bosch, Mathieu [Texas A & M Univ., College Station, TX (United States); Zhou, Hong-Cai [Texas A & M Univ., College Station, TX (United States)
2015-03-04
Knowledge about the interactions between gas molecules and adsorption sites is essential to customize metal-organic frameworks (MOFs) as adsorbents. The dynamic interactions occurring during adsorption/desorption working cycles with several states are especially complicated. Even so, the gas dynamics based upon experimental observations and the distribution of guest molecules under various conditions in MOFs have not been extensively studied yet. In this work, a direct time-resolved diffraction structure envelope (TRDSE) method using sequential measurements by in situ synchrotron powder X-ray diffraction has been developed to monitor several gas dynamic processes taking place in MOFs: infusion, desorption, and gas redistribution upon temperature change. The electron density maps indicate that gas molecules prefer to redistribute over heterogeneous types of sites rather than to exclusively occupy the primary binding sites. We found that the gas molecules are entropically driven from open metal sites to larger neighboring spaces during the gas infusion period, matching the localized-to-mobile mechanism. In addition, the partitioning ratio of molecules adsorbed at each site varies with different temperatures, as opposed to an invariant distribution mode. Equally important, the gas adsorption in MOFs is intensely influenced by the gas–gas interactions, which might induce more molecules to be accommodated in an orderly compact arrangement. This sequential TRDSE method is generally applicable to most crystalline adsorbents, yielding information on distribution ratios of adsorbates at each type of site.
19. Solid waste from leather industry as adsorbent of organic dyes in aqueous-medium
Energy Technology Data Exchange (ETDEWEB)
Oliveira, Luiz C.A. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil)]. E-mail: [email protected]; Goncalves, Maraisa [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Oliveira, Diana Q.L. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Guerreiro, Mario C. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Guilherme, Luiz R.G. [Universidade Federal de Lavras, Depto. de Ciencia do solo, CEP 37200.000, Lavras-MG (Brazil); Dallago, Rogerio M. [URI-Campus Erechim, Av. 7 Setembro 1621, Centro, CEP 99700-000, Depto de Quimica, Erechim-RS (Brazil)
2007-03-06
The industrial tanning of leather usually produces considerable amounts of chromium-containing solid waste and liquid effluents and raises many concerns on its environmental effect as well as on escalating landfill costs. Actually, these shortcomings are becoming increasingly a limiting factor to this industrial activity that claims for alternative methods of residue disposals. In this work, it is proposed a novel alternative destination of the solid waste, based on the removal of organic contaminants from the out coming aqueous-residue. The adsorption isotherm pattern for the wet blue leather from the Aurea tanning industry in Erechim-RS (Brazil) showed that these materials present high activity on adsorbing the reactive red textile dye as well as other compounds. The adsorbent materials were characterized by IR spectroscopy and SEM and tested for the dye adsorption (reactive textile and methylene blue dyes). The concentrations of dyes were measured by UV-vis spectrophotometry and the chromium extraction from leather waste was realized by basic hydrolysis and determined by atomic absorption. As a low cost abundant adsorbent material with high adsorption ability on removing dye methylene blue (80 mg g{sup -1}) and textile dye reactive red (163 mg g{sup -1}), the leather waste is revealed to be a interesting alternative relatively to more costly adsorbent materials.
20. Solid waste from leather industry as adsorbent of organic dyes in aqueous-medium
International Nuclear Information System (INIS)
The industrial tanning of leather usually produces considerable amounts of chromium-containing solid waste and liquid effluents and raises many concerns on its environmental effect as well as on escalating landfill costs. Actually, these shortcomings are becoming increasingly a limiting factor to this industrial activity that claims for alternative methods of residue disposals. In this work, it is proposed a novel alternative destination of the solid waste, based on the removal of organic contaminants from the out coming aqueous-residue. The adsorption isotherm pattern for the wet blue leather from the Aurea tanning industry in Erechim-RS (Brazil) showed that these materials present high activity on adsorbing the reactive red textile dye as well as other compounds. The adsorbent materials were characterized by IR spectroscopy and SEM and tested for the dye adsorption (reactive textile and methylene blue dyes). The concentrations of dyes were measured by UV-vis spectrophotometry and the chromium extraction from leather waste was realized by basic hydrolysis and determined by atomic absorption. As a low cost abundant adsorbent material with high adsorption ability on removing dye methylene blue (80 mg g-1) and textile dye reactive red (163 mg g-1), the leather waste is revealed to be a interesting alternative relatively to more costly adsorbent materials
1. Evaluation of organic and inorganic adsorbents for the removal of uranium and plutonium from process streams
Energy Technology Data Exchange (ETDEWEB)
Herald, W.R.; Koenst, J.W.; Luthy, D.F.
1977-01-01
Mound Laboratory is evaluating macroporous, ion exchange resins for the removal of plutonium, uranium, and various colloids from process waste treatment effluents. A number of organic ion exchange resins were evaluated for removal of /sup 238/Pu(IV), /sup 238/Pu(VI), and /sup 233/U(VI) from water using batch isotherm tests. The capacity and equilibrium distribution coefficients were compared with each other and with bone char, an inorganic adsorbent consisting of hydroxyapatite (HAP). The various types of adsorbents showed that the extent of removal and the equilibrium coefficients (Kd) were functions of pH. For removal of polymeric plutonium, /sup 238/Pu(IV), the best results were achieved using the inorganic adsorbent, bone char (hydroxyapatite), at pH 7. However, macroporous, weak base, anion exchange resins also showed reasonable Kd values at pH 7. Therefore, the best removal of polymeric plutonium can be achieved using chemisorption or weak base anionic exchange, indicating strongly ionized anions. Excellent results for removal of /sup 238/Pu(VI) were achieved using macroporous, strong base, anion exchange resins and macroporous, strong acid, cation exchange resins. For removal of ionic /sup 233/U(VI), the strongly acidic cation exchangers gave the better results; the Kd values were on the order of 10/sup 2/ better than bone char. Again, performance was strongly dependent upon pH. Adsorbent resins which remove constituents by physical adsorption did not perform well for uranium removal.
2. Atomic force microscopy measurements of topography and friction on dotriacontane films adsorbed on a SiO2 surface
DEFF Research Database (Denmark)
Trogisch, S.; Simpson, M.J.; Taub, H.;
2005-01-01
We report comprehensive atomic force microscopy (AFM) measurements at room temperature of the nanoscale topography and lateral friction on the surface of thin solid films of an intermediate-length normal alkane, dotriacontane (n-C32H66), adsorbed onto a SiO2 surface. Our topographic and frictional...... images, recorded simultaneously in the contact mode, reveal a multilayer structure in which one to two layers of molecules adsorb adjacent to the SiO2 surface oriented with their long axis parallel to the interface followed by partial layers of molecules oriented perpendicular to the surface. The...
3. Organic and Inorganic Dyes in Polyelectrolyte Multilayer Films
Directory of Open Access Journals (Sweden)
Vincent Ball
2012-12-01
Full Text Available Polyelectrolyte multilayer films are a versatile functionalization method of surfaces and rely on the alternated adsorption of oppositely charged species. Among such species, charged dyes can also be alternated with oppositely charged polymers, which is challenging from a fundamental point of view, because polyelectrolytes require a minimal number of charges, whereas even monovalent dyes can be incorporated during the alternated adsorption process. We will not only focus on organic dyes but also on their inorganic counterparts and on metal complexes. Such films offer plenty of possible applications in dye sensitized solar cells. In addition, dyes are massively used in the textile industry and in histology to stain textile fibers or tissues. However, the excess of non bound dyes poses serious environmental problems. It is hence of the highest interest to design materials able to adsorb such dyes in an almost irreversible manner. Polyelectrolyte multilayer films, owing to their ion exchange behavior can be useful for such a task allowing for impressive overconcentration of dyes with respect to the dye in solution. The actual state of knowledge of the interactions between charged dyes and adsorbed polyelectrolytes is the focus of this review article.
4. Adsorbed films of three-patch colloids: continuous and discontinuous transitions between thick and thin films.
Science.gov (United States)
Dias, C S; Araújo, N A M; Telo da Gama, M M
2014-09-01
We investigate numerically the role of spatial arrangement of the patches on the irreversible adsorption of patchy colloids on a substrate. We consider spherical three-patch colloids and study the dependence of the kinetics on the opening angle between patches. We show that growth is suppressed below and above minimum and maximum opening angles, revealing two absorbing phase transitions between thick and thin film regimes. While the transition at the minimum angle is continuous, in the directed percolation class, that at the maximum angle is clearly discontinuous. For intermediate values of the opening angle, a rough colloidal network in the Kardar-Parisi-Zhang universality class grows indefinitely. The nature of the transitions was analyzed in detail by considering bond flexibility, defined as the dispersion of the angle between the bond and the center of the patch. For the range of flexibilities considered we always observe two phase transitions. However, the range of opening angles where growth is sustained increases with flexibility. At a tricritical flexibility, the discontinuous transition becomes continuous. The practical implications of our findings and the relation to other nonequilibrium transitions are discussed. PMID:25314441
5. XPS study of the surfactant film adsorbed onto growing titania nanoparticles
International Nuclear Information System (INIS)
TiO2 particles, prepared by following a sol-gel preparative route, were submitted to hydrothermal growing stages in the presence of an anionic surfactant, sodium dodecyl-sulfate (SDS), at solution pH values corresponding, respectively, to positive surface charges and to the isoelectric point of the oxide. The concentration of the surfactant in the aqueous solution was varied in order to produce different conditions of self-aggregation between the amphiphilic molecules. XPS analyses were performed on the aged and dried precursors to characterize the surfactant films adsorbed onto the oxide. The regions of Ti 2p, O 1s, and C 1s were specifically investigated. The samples, calcined at 600 deg. C, were characterized for phase composition-crystallinity, by X-ray diffraction, and for surface area. The role played by the oxide-surfactant interactions and by the surfactant self-aggregation phenomena in affecting the physico-chemical properties of the powders is discussed
6. Development of adsorbent for the simultaneous removal of organic and inorganic contaminants from aqueous solution.
Science.gov (United States)
Choi, J W; Chung, S G; Hong, S W; Kim, D J; Lee, S H
2011-01-01
In this study, a modified adsorbent, alginate complex beads, was prepared and applied to the removal of mixed contaminants from wastewater. The alginate complex beads were generated by the immobilization of powdered activated carbon and synthetic zeolites onto alginate gel beads, which were then dried at 110 °C for 20 h until the diameter had been reduced to 1 mm. This dry technique increased the hardness of the adsorbent to assure its durability and application. The adsorption onto the alginate complex beads of organic and inorganic compounds, as target contaminants, was investigated by performing both equilibrium and kinetic batch experiments. From the adsorption isotherms, according to the Langmuir equation, the alginate complex bead was capable of effectively removing benzene, toluene, zinc and cadmium. From kinetic batch experiments, the removal efficiencies of benzene, toluene, zinc and cadmium were found to be 66.5, 92.4, 74.1 and 76.7%, respectively, for initial solution concentrations of 100 mg L(-1). The results indicated that the adsorbent developed in this study has the potential to be a promising material for the removal of mixed pollutants from industrial wastewater or contaminated groundwater. PMID:22020474
7. Ionic liquids supported on metal-organic frameworks: remarkable adsorbents for adsorptive desulfurization.
Science.gov (United States)
Khan, Nazmul Abedin; Hasan, Zubair; Jhung, Sung Hwa
2014-01-01
Acidic ionic-liquids (IL) supported on metal-organic frameworks (MOFs) have been shown to be beneficial for adsorptive desulfurization. A remarkable improvement in the adsorption capacity (ca. 71%) was observed in for ILs supported on MIL-101 compared with virgin MIL-101. The improved adsorptive performance might be explained by the acid-base interactions between the acidic ionic liquid and basic benzothiophene (BT). Moreover, from this study, it can be suggested that porous MOFs, supported with ionic liquids, may introduce a new class of highly porous adsorbents for the efficient adsorption of various compounds. PMID:24390909
8. Mixed waste remediation using HUMASORB trademark -- an adsorbent to remove organic and inorganic contaminants
International Nuclear Information System (INIS)
The groundwater contamination at different Department of Energy (DOE) and other similar industrial sites is complex due to the presence of both volatile organic compounds (VOC) and heavy metals. ARCTECH, Inc. is developing a process based on HUMASORB trademark--a humic acid based adsorbent, to remove heavy metal, radionuclide and organic contaminants from groundwater and surface water streams in one processing step. The properties of HUMASORBtrademark that are useful for mixed waste remediation include: high cation exchange capacity; ability to chelate metals; and ability to adsorb organics. The starting materials for the development of HUMASORBtrademark is actosol reg-sign, a humic acid based soil amendment product manufactured by ARCTECH, Inc. Humic acid isolated from actosol reg-sign was purified, and cross-linked by different methods to make HUMASORB trademark. This material was then used for contaminant removal from both an actual waste stream from a Superfund site and simulated waste streams containing contaminants such as heavy metals, radionuclides, chlorinated and fuel hydrocarbons. Adsorption and metal sorption isotherms were developed for different contaminants
9. The effects of adsorbing organic pollutants from super heavy oil wastewater by lignite activated coke.
Science.gov (United States)
Tong, Kun; Lin, Aiguo; Ji, Guodong; Wang, Dong; Wang, Xinghui
2016-05-01
The adsorption of organic pollutants from super heavy oil wastewater (SHOW) by lignite activated coke (LAC) was investigated. Specifically, the effects of LAC adsorption on pH, BOD5/COD(Cr)(B/C), and the main pollutants before and after adsorption were examined. The removed organic pollutants were characterized by Fourier transform infrared spectroscopy (FTIR), Boehm titrations, gas chromatography-mass spectrometry (GC-MS), and liquid chromatography with organic carbon detection (LC-OCD). FTIR spectra indicated that organic pollutants containing -COOH and -NH2 functional groups were adsorbed from the SHOW. Boehm titrations further demonstrated that carboxyl, phenolic hydroxyl, and lactonic groups on the surface of the LAC increased. GC-MS showed that the removed main organic compounds are difficult to be degraded or extremely toxics to aquatic organisms. According to the results of LC-OCD, 30.37 mg/L of dissolved organic carbons were removed by LAC adsorption. Among these, hydrophobic organic contaminants accounted for 25.03 mg/L. Furthermore, LAC adsorption was found to increase pH and B/C ratio of the SHOW. The mechanisms of adsorption were found to involve between the hydrogen bonding and the functional groups of carboxylic, phenolic, and lactonic on the LAC surface. In summary, all these results demonstrated that LAC adsorption can remove bio-refractory DOCs, which is beneficial for biodegradation. PMID:26808249
10. Metallo-Organic Decomposition (MOD) film development
Science.gov (United States)
Parker, J.
1986-01-01
The processing techniques and problems encountered in formulating metallo-organic decomposition (MOD) films used in contracting structures for thin solar cells are described. The use of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques performed at Jet Propulsion Laboratory (JPL) in understanding the decomposition reactions lead to improvements in process procedures. The characteristics of the available MOD films were described in detail.
11. Performance of non-coconut base adsorbers in removal of iodine and organic iodides
International Nuclear Information System (INIS)
Systems for the removal of radioactive iodine and organic iodides have used impregnated coconut shell activated carbons almost exclusively. Coconut shell carbons have some disadvantages: their geographical origin determines their trace chemical content; pore structures and impregnant effectiveness are highly dependent on activation and impregnation techniques. The authors report laboratory performance of a group of iodine-organic iodide adsorbers using bases other than coconut shell carbon. These have been evaluated in conformity with USAEC Regulatory Guide 1.52 and RDT M16 1T. Performance with regard to 131I2 and CH3131I penetration and high-temperature elution have equaled or exceeded both the requirements of Guide 1.52 and results on typical coconut-shell carbons. Some performance outside Guide 1.52 ranges is included. Experimental problems in simulated LOCA testing are discussed. (U.S.)
12. Mixed waste: The treatment of organic radioactive waste by means of adsorbents
International Nuclear Information System (INIS)
Full text: The work described in this paper has been carried in the radioactive waste treatment facilities of the Nuclear Research Center Lo Aguirre, CEN LA, which are operated by Radioactive Waste Management Unit, UGDR. This last, centralizes its activities in order to manage all radioactive waste generated in the country due to the nuclear development. Features of danger and risks presented by organic radioactive liquid waste, make the need to develop a practicable alternative for its treatment and to allow the conditioning towards a suitable final disposal The raw material for this work, is an organic liquid waste arising from scintillation techniques, contaminated with Tritium. This mixed waste has to be treated and then conditioned in a solid form within a 200 I container, according with actual acceptance criteria for our temporary store for radioactive waste. The best formulation which allows to immobilize the liquid waste was determined. The first step consists in the adsorption treatment that waste is humbled. From the available adsorbents, two types were studied: adsorption granulat and diatomaceous earth. From the waste management standpoint, results with diatomaceous earth present physical characteristics better than the other Following, the second stage is the immobilization, which is achieved in a cement matrix made with puzzolanic cement (Polpaico 400) made in Chile. Later, due to cost and availability in the country, the diatomaceous earth is selected for the study, in the form of celite which is comparatively economic. The best mixture, with regard to physical feature, has the following composition: a 0.35 (w/w) water/cement ratio, which represents the needed quantity to obtain workability in the mixture, and it is the minimum amount of water to hydrating the cement; a waste/adsorbent ratio of 0.5 (v/v), in which the organic liquid is completely adsorbed and it is incorporated into the crystalline system of the solid form; and an adsorbed waste
13. Ellipsometry of functional organic surfaces and films
CERN Document Server
Hinrichs, Karsten
2013-01-01
Ellipsometry is the method of choice to determin the properties of surfaces and thin films. It provides comprehensive and sensitive characterization in a contactless and non-invasive measurements. This book gives a state-of-the-art survey of ellipsometric investigations of organic films and surfaces, from laboratory to synchrotron applications, with a special focus on in-situ use in processing environments and at solid-liquid interfaces.
14. Injection currents in thin disordered organic films
International Nuclear Information System (INIS)
Analytic model of barrier-limited injection of charge carriers from metal electrodes into organic film, which was introduced by Arkhipov and co-workers, is modified, considering effects of multiple image charges and injection from both electrodes. Limits of applicability of Arkhipov's model are discussed. Variations from Arkhipov's model are important, if film thickness is comparable with Onsager length
15. Low concentration CO2 capture using physical adsorbents: Are Metal-Organic Frameworks becoming the new benchmark materials?
KAUST Repository
Belmabkhout, Youssef
2016-03-30
The capture and separation of traces and concentrated CO2 from important commodities such as CH4, H2, O2 and N2, is becoming important in many areas related to energy security and environmental sustainability. While trace CO2 concentration removal applications have been modestly studied for decades, the spike in interest in the capture of concentrated CO2 was motivated by the need for new energy vectors to replace highly concentrated carbon fuels and the necessity to reduce emissions from fossil fuel-fired power plants. CO2 capture from various gas streams, at different concentrations, using physical adsorbents, such as activated carbon, zeolites, and metal-organic frameworks (MOFs), is attractive. However, the adsorbents must be designed with consideration of many parameters including CO2 affinity, kinetics, energetics, stability, capture mechanism, in addition to cost. Here, we perform a systematic analysis regarding the key technical parameters that are required for the best CO2 capture performance using physical adsorbents. We also experimentally demonstrate a suitable material model of Metal Organic Framework as advanced adsorbents with unprecedented properties for CO2 capture in a wide range of CO2 concentration. These recently developed class of MOF adsorbents represent a breakthrough finding in the removal of traces CO2 using physical adsorption. This platform shows colossal tuning potential for more efficient separation agents.
16. Effect of alkane chain length and counterion on the freezing transition of cationic surfactant adsorbed film at alkane mixture - water interfaces.
Science.gov (United States)
Tokiwa, Yuhei; Sakamoto, Hiroyasu; Takiue, Takanori; Aratono, Makoto; Matsubara, Hiroki
2015-05-21
Penetration of alkane molecules into the adsorbed film gives rise to a surface freezing transition of cationic surfactant at the alkane-water interface. To examine the effect of the alkane chain length and counterion on the surface freezing, we employed interfacial tensiometry and ellipsometry to study the interface of cetyltrimethylammonium bromide and cetyltrimethylammonium chloride aqueous solutions against dodecane, tetradecane, hexadecane, and their mixtures. Applying theoretical equations to the experimental results obtained, we found that the alkane molecules that have the same chain length as the surfactant adsorb preferentially into the surface freezing film. Furthermore, we demonstrated that the freezing transition temperature of cationic surfactant adsorbed film was independent of the kind of counterion. PMID:25932500
17. Organic silicon compounds anf hydrogen sulfide removal from biogas by mineral and adsorbent
Science.gov (United States)
Choi, J.
2015-12-01
Biogas utilized for energy production needs to be free from organic silicon compounds and hydrogen sulfide , as their burning has damaging effects on utilities and humans; organic silicon compounds and hydrogen sulfide can be found in biogas produced from biomass wastes, due to their massive industrial use in synthetic product,such as cosmetics, detergents and paints.Siloxanes and hydrogen sulfide removal from biogas can be carried out by various methods (Ajhar et al., 2010); aim of the present work is to find a single practical andeconomic way to drastically and simultaneously reduce both hydrogen sulfide and the siloxanes concentration to less than 1 ppm. Some commercial activated carbons previously selected (Monteleoneet al., 2011) as being effective in hydrogen sulfide up taking have been tested in an adsorption measurement apparatus, by flowing both hydrogen sulphide and volatile siloxane (Decamethycyclopentasiloxane or D5) in a nitrogen stream,typically 25-300 ppm D5 over N2, through an clay minerals, Fe oxides and Silica; the adsorption process was analyzed by varying some experimental parameters (concentration, grain size, bed height). The best silica shows an adsorption capacity of 0.2 g D5 per gram of silica. The next thermo gravimetric analysis (TGA) confirms the capacity data obtained experimentally by the breakthrough curve tests.The capacity results depend on D5 and hydrogen sulphide concentrations. A regenerative silica process is then carried out byheating the silica bed up to 200 ° C and flushing out the adsorbed D5 and hydrogen sulphide samples in a nitrogen stream in athree step heating procedure up to 200 ° C. The adsorption capacity is observed to degrade after cyclingthe samples through several adsorption-desorption cycles.
18. The inter-adsorbate interaction mediated by Shockley-type surface state electrons and dipole moment: Cs and Ba atoms absorbed on Ag (1 1 1) films
International Nuclear Information System (INIS)
Through first-principles investigation, we display the formation process of Shockley-type surface states which emerges on silver thin films along Ag (1 1 1) orientation with increasing thicknesses from 6 to 21 layers. We look at the surface state band for various adatoms adsorbed on 6, 12, 18 layers strained Ag (1 1 1) films with different coverage, and discuss the long range interaction mediated by surface state electrons. We discovered that film's thickness can modulate the surface state mediated interaction drastically, but the dipole–dipole repulsive interaction is not affected by slab thickness. This factor had never been discussed in detail. Therefore, adatoms adsorbed on thin films have strong attractive interaction which leads to small adsorption separation and the tendency of island formation. For different coverage or different adsorbate types, both surface states and dipole moment are modulated. The three factors, film's thickness, adsorbate coverage and adatoms types, could help us learn more about the interactions between adatoms and exploit advanced ways to control surface geometry structures of self-assembly.
19. Methyl red removal from water by iron based metal-organic frameworks loaded onto iron oxide nanoparticle adsorbent
Energy Technology Data Exchange (ETDEWEB)
Dadfarnia, S., E-mail: [email protected] [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Haji Shabani, A.M.; Moradi, S.E. [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Emami, S. [Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)
2015-03-01
Highlights: • Synthesis and characterization of (Fe{sub 3}O{sub 4}@MIL-100(Fe)). • Studying the capability of (Fe{sub 3}O{sub 4}@MIL-100(Fe)) for the removal of methyl red. • Studying the adsorption kinetic of MR on (Fe{sub 3}O{sub 4}@MIL-100(Fe)). • Studying the adsorption thermodynamic of MR on (Fe{sub 3}O{sub 4}@MIL-100(Fe)). • Introduction of a sorbent with high capacity for MR removal. - Abstract: The objective followed by this research is the synthesis of iron based metal organic framework loaded on iron oxide nanoparticles (Fe{sub 3}O{sub 4}@MIL-100(Fe)) and the study of its capability for the removal of methyl red. Effective parameters in the selection of a new adsorbent, i.e. adsorption capacity, thermodynamics, and kinetics were investigated. All the studies were carried out in batch experiments. Removal of methyl red from aqueous solutions varied with the amount of adsorbent, methyl red contact time, initial concentration of dye, adsorbent dosage, and solution pH. The capability of the synthesized adsorbent in the removal of methyl red was compared with the metal organic framework (MIL-100(Fe)) and iron oxide nanoparticles. The results show that Fe{sub 3}O{sub 4}@MIL-100(Fe) nanocomposite exhibits an enhanced adsorption capacity.
20. Methyl red removal from water by iron based metal-organic frameworks loaded onto iron oxide nanoparticle adsorbent
International Nuclear Information System (INIS)
Highlights: • Synthesis and characterization of (Fe3O4@MIL-100(Fe)). • Studying the capability of (Fe3O4@MIL-100(Fe)) for the removal of methyl red. • Studying the adsorption kinetic of MR on (Fe3O4@MIL-100(Fe)). • Studying the adsorption thermodynamic of MR on (Fe3O4@MIL-100(Fe)). • Introduction of a sorbent with high capacity for MR removal. - Abstract: The objective followed by this research is the synthesis of iron based metal organic framework loaded on iron oxide nanoparticles (Fe3O4@MIL-100(Fe)) and the study of its capability for the removal of methyl red. Effective parameters in the selection of a new adsorbent, i.e. adsorption capacity, thermodynamics, and kinetics were investigated. All the studies were carried out in batch experiments. Removal of methyl red from aqueous solutions varied with the amount of adsorbent, methyl red contact time, initial concentration of dye, adsorbent dosage, and solution pH. The capability of the synthesized adsorbent in the removal of methyl red was compared with the metal organic framework (MIL-100(Fe)) and iron oxide nanoparticles. The results show that Fe3O4@MIL-100(Fe) nanocomposite exhibits an enhanced adsorption capacity
1. Novel magnetic Fe3O4-C nanoparticles as adsorbents for removal of organic dyes from aqueous solution
International Nuclear Information System (INIS)
Highlights: → In this work, novel magnetic Fe3O4-C nanoparticles have been synthesized and employed as high efficient adsorbent for removal cationic dyes from polluted water. → While up to now, little study is done on adsorption of dyes by the Fe3O4-C nanoparticles. → Hence, here we provide a simply and environment friendly method for removal of cationic dyes or other pollutants from water. - Abstract: The magnetic Fe3O4/C core-shell nanoparticles have been synthesized by a simple strategy and used as adsorbents for removal of organic dyes from aqueous solution. The resulting products are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectra (FTIR). Adsorption performances of the nanomaterial adsorbents are tested with removal of methylene blue (MB) and cresol red (CR) from aqueous solution. The effects of solution pH value, adsorption time and capacity of the nanocomposites have been fully investigated. The results reveal that the nanospheres can be easily manipulated by an external magnetic field with high separation efficiency. In addition, the process is clean and safe for purifying water pollution. The prepared Fe3O4/C complex nanomaterials could thus be used as promising adsorbents for the remove organic dyes, especially, cationic dye, from polluted water.
2. Low concentration volatile organic pollutants removal in combined adsorber-desorber-catalytic reactor system
Directory of Open Access Journals (Sweden)
Arsenijević Zorana
2008-01-01
Full Text Available The removal of volatile organic compounds (VOCs from numerous emission sources is of crucial importance due to more rigorous demands on air quality. Different technologies can be used to treat the VOCs from effluent gases: absorption, physical adsorption, open flame combustion, thermal and catalytic incineration. Their appropriateness for the specific process depends on several factors such as efficiency, energy consumption, secondary pollution, capital investments etc. The distinctive features of the catalytic combustion are high efficiency and selectivity toward benign products, low energy consumption and absence of secondary pollution. The supported noble catalysts are widely used for catalytic incineration due to their low ignition temperatures and high thermal and chemical stability. In our combined system adsorption and desorption are applied in the spouted bed with draft tube (SBDT unit. The annular zone, loaded with sorbent, was divided in adsorption and desorption section. Draft tube enabled sorbent recirculation between sections. Combustion of desorbed gases to CO2 and water vapor are realized in additive catalytic reactor. This integrated device provided low concentrations VOCs removal with reduced energy consumption. Experiments were conducted on a pilot unit of 220 m3/h nominal capacity. The sorbent was activated carbon, type K81/B - Trayal Corporation, Krusevac. A sphere shaped commercial Pt/Al2O3 catalyst with "egg-shell" macro-distribution was used for the investigation of xylene deep oxidation. Within this paper the investigations of removal of xylene vapors, a typical pollutant in production of liquid pesticides, in combined adsorber/desorber/catalytic reactor system is presented.
3. Surface morphology and thickness of a multilayer film composed of strong and weak polyelectrolytes: Effect of the number of adsorbed layers, concentration and type of salts
International Nuclear Information System (INIS)
Self-assembled multilayered films were prepared by alternate deposition of a strong cationic polyelectrolyte, poly(trimethylammonium ethyl methacrylate chloride) and a pH-dependant anionic polyelectrolyte, poly(acrylic acid). The layer-by-layer adsorption was followed in-situ by optical fixed-angle reflectometry and after drying by ellipsometry. A recently developed 'substrate thickness method' was applied to calculate the adsorbed amount of polymer from the reflectometric signal. Surface film morphology was imaged before and after drying with atomic force microscopy (AFM). Influence of the number of adsorbed layers, concentration and type of salts on the multilayer growth was examined. The number of adsorbed layers produced a specific effect on the reflectometric signal which is linked to the refractive index of the film. Adjustment of the adsorbed amount of polyelectrolytes was done by changing sodium chloride salt concentration within a range of 10-3 to 10-1 M. AFM observations showed a significant evolution in surface morphology and a maximum of surface roughness for films built-up at 10-2 M. Experiments were then carried out at 10-3 M in either barium chloride or zinc chloride salts. In the presence of Ba2+ and Zn2+ ions, adsorption of 5 bilayers is completely modified and the surface morphology was smoother than the multilayers obtained using sodium chloride salt
4. Treatment of Adsorbable Organic Halides from Recycled Paper Industry Wastewater using a GAC-SBBR Pilot Plant System
OpenAIRE
Khadum, A.A.H.; Rahman, R.A.; Mohamad, A.B.; S.R.S. Abdullah; M.H. Muhamad
2011-01-01
Wastewater originating from recycled paper industry is known to be potentially toxic/inhibitory. Adsorbable Organic Halides (AOX) are among the toxic constituents generated from the recycled paper industry. The problems associated with AOX in the environment are their accumulation in the food chain and their persistence in nature. Hence, it is imperative to improve the effluent quality emanating from the recycled paper industry in order to meet the future discharge limits. One the plausible t...
5. Use of Low-cost Adsorbents to Chlorophenols and Organic Matter Removal of Petrochemical Wastewater
Directory of Open Access Journals (Sweden)
Aretha Moreira de Oliveira
2013-11-01
Full Text Available The removal of 2,4 diclorophenol (2,4-DCF and 2,4,6 trichlorophenol (2,4,6 TCF present in petrochemical wastewater was evaluated using low-cost adsorbents, such as chitin, chitosan and coconut shells. Batch studies showed that the absorption efficiency for 2,4 DCF and 2,4,6 TCF follow the order: chitosan > chitin > coconut shells. Langmuir and Freundlich models have been applied to experimental isotherms data, to better understand the adsorption mechanisms. Petrochemical wastewater treatment with fixed bed column system using chitinous adsorbents showed a removal of COD (75% , TOG (90% and turbidity (74-89%.
6. Entropy-Driven Conformational Control of α,ω-Difunctional Bidentate-Dithiol Azo-Based Adsorbates Enables the Fabrication of Thermally Stable Surface-Grafted Polymer Films.
Science.gov (United States)
Lee, Han Ju; Jamison, Andrew C; Lee, T Randall
2016-06-22
Thermally stable radical initiator monolayers were prepared from uniquely designed α,ω-difunctional adsorbates with bidentate headgroups for the growth of nanoscale polymer films on metal surfaces. The length of the spacer separating the bidentate headgroups was varied to afford 4,4'-(diazene-1,2-diyl)bis(N-(16-(3,5-bis(mercaptomethyl)phenoxy)hexadecyl)-4-cyanopentanamide) (B16), 4,4'-(diazene-1,2-diyl)bis(N-(16-(3,5-bis(mercapto-methyl)phenoxy)decyl)-4-cyanopentanamide) (B10), and 4,4'-(diazene-1,2-diyl)bis(N-(4-(3,5-bis(mercaptomethyl)phenoxy)butyl)-4-cyanopentanamide) (B4). The structural features of the self-assembled monolayers (SAMs) derived from B16, B10, and B4 were characterized by X-ray photoelectron spectroscopy (XPS), ellipsometry, and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and compared to those derived from an analogous α,ω-difunctional adsorbate with monodentate headgroups, 4,4'-(diazene-1,2-diyl)bis(4-cyano-N-(16-mercaptohexadecyl)pentanamide (M). These studies demonstrate that the conformation (i.e., hairpin vs standing up) of the bidentate initiator adsorbates on gold surfaces was easily controlled by adjusting the concentration of the adsorbates in solution. The results of solution-phase thermal desorption tests revealed that the radical initiator monolayers generated from B16, B10, and B4 exhibit an enhanced thermal stability when compared to those generated from M. Furthermore, a study of the growth of polymer films was performed to evaluate the utility of these new bidentate adsorbate SAMs as film-development platforms for new functional materials and devices. Specifically, surface-grafted polystyrene films were successfully generated from SAMs derived from B16. In contrast, attempts to grow polystyrene films from SAMs derived from M under a variety of analogous conditions were unsuccessful. PMID:27219525
7. NMR diffusion and relaxation measurements of organic molecules adsorbed in porous media
International Nuclear Information System (INIS)
a bipolar form of the pulsed field gradient has proved to be an efficient method for both reducing the cross-term between the applied and internal gradient and reducing the eddy current dead time. Without the use of a bipolar sequence, the measured diffusivities are likely to be underestimated. In order to get sufficient attenuation of the signal a stimulated-echo sequence together with magnetic field gradients have been used. It was then possible to increase the z-storage period to compensate for insufficient gradient strength. However, the employed diffusion probe and gradient power supply are able to generate magnetic field gradients that make the z-storage period unnecessary. In this work we also present a spin-echo analogue to the 13-interval PFGSTE sequence presented by Cotts et al., a so-called 11-interval bipolar PFGSE sequence. Conclusions: The molecular dynamics of four organic adsorbates confined in porous materials have been investigated. The confinement gives rise to substantial changes in the phase behaviour and molecular dynamics. From the line shape of the confined substances a narrow-line component superimposed on a broad resonance is observed at temperatures well below the transition point of the bulk material. This narrow-line component is, in the freezing region, attributed to the surface layer and the undercooled liquid in the smaller pores that remains unfrozen. In the low-temperature region, the narrow-line component corresponds to the surface layer, while the broad component originates from the crystalline phase at the centre of the pores. The persistent surface layer does not appear to crystallize at all, and a relatively high diffusion rate of this liquid-like phase is observed over a wide temperature range, even well below the transition point of the bulk material. However, with decreasing temperature T2 of the molecules in the surface layer becomes shorter and the contribution to the NMR signal decreases gradually. For pivalic acid and
8. Neutron scattering study of 36 Ar monolayer films adsorbed on graphite
DEFF Research Database (Denmark)
Taub, H.; da Costa Carneiro, Kim; Kjems, Jørgen;
1977-01-01
scattered from 36 Ar monolayers in the nominally in-plane configuration can be reasonably well described at low temperatures by a 2D harmonic-phonon model while the scattering in the out-of-plane configuration seems to be best represented in terms of a resonant coupling of the monolayer film to out......-of-plane collective motions of the graphite substrate. There is some evidence of renormalization of the in-plane transverse modes of the monolayer at higher temperatures; however, the in-plane longitudinal modes and the out-of-plane modes do not appear to be similarly affected....
9. Third Sound Generation in Superfluid 4He Films Adsorbed on Multiwall Carbon Nanotubes
Science.gov (United States)
Iaia, Vito; Menachekanian, Emin; Williams, Gary
2014-03-01
A technique is developed for generating third sound in superfluid 4He films coating the surface of multiwall carbon nanotubes. Third sound is a thickness and temperature wave of the helium film, and in our case we detect the temperature oscillations with a carbon resistance bolometer. The nanotubes are packed in an annular resonator that is vibrated with a mechanical shaker assembly consisting of a permanent magnet mounted on springs, and surrounded by a superconducting coil. The coil is driven with an oscillating current, vibrating the cell at that frequency. Sweeping the drive frequency over the range 100-200 Hz excites the resonant third sound mode of the cell, seen as a high-Q signal in the FFT analysis of the bolometer signal. A problem with our original cell was that the mechanical drive would also shake the dilution refrigerator cooling the cell to low temperatures, and increasing the drive would start to heat up the refrigerator and the cell, which were rigidly coupled together. A new configuration now suspends the cell as a pendulum on a string, with thermal contact made by copper wires. Piezo sensor measurements show this reduces the vibration reaching the refrigerator by two orders of magnitude, which should allow measurements at lower temperatures.
10. Scanning tunneling microscopy studies of organic monolayers adsorbed on the rhodium(111) crystal surface
Energy Technology Data Exchange (ETDEWEB)
Cernota, Paul D.
1999-08-01
Scanning Tunneling Microscopy studies were carried out on ordered overlayers on the (111) surface of rhodium. These adsorbates include carbon monoxide (CO), cyclohexane, cyclohexene, 1,4-cyclohexadiene, para-xylene, and meta-xylene. Coadsorbate systems included: CO with ethylidyne, CO with para- and meta-xylene, and para-xylene with meta-xylene. In the case of CO, the structure of the low coverage (2x2) overlayer has been observed. The symmetry of the unit cell in this layer suggests that the CO is adsorbed in the 3-fold hollow sites. There were also two higher coverage surface structures with ({radical}7x{radical}7) unit cells. One of these is composed of trimers of CO and has three CO molecules in each unit cell. The other structure has an additional CO molecule, making a total of four. This extra CO sits on a top site.
11. Adsorption of organic layers over electrodeposited magnetite (Fe3O4) thin films
International Nuclear Information System (INIS)
Research highlights: → Adherent low roughness magnetite films ranging from 80 nm to 3.75 μm-thick were electrodeposited on Au/glass substrates under galvanostatic control. → X-ray diffraction and magnetic measurements corroborates the purity of the electrodeposited magnetite. → Both dodecanethiol and oleic acid are shown to adsorb on the magnetite prepared at low temperature, significantly inducing the hydrophobicity of the surface. → Contact angle and voltammetric measurements, as well as XPS confirm the monolayers formation. - Abstract: The formation of monolayers of two organic compounds (oleic acid and dodecanethiol) over magnetite films was studied. Magnetite films ranging from 80 nm to 3.75 μm-thick were electrodeposited on Au on glass substrates under galvanostatic control, with deposition parameters optimized for minimum surface roughness. Films were characterised by SEM and AFM, showing granular deposits with a low rms roughness of 5-40 nm measured over an area of 1 μm2. The growth rate was estimated by measuring cross-sections of the thin films. Pure magnetite with an fcc structure is observed in XRD diffractograms. The adsorption of both oleic acid and dodecanethiol on the magnetite films was tested by immersing them in ethanol solutions containing the organic molecules, for different deposition time, temperature and cleaning procedure. Monolayer formation in both cases was studied by contact angle and voltammetric measurements, as well as XPS.
12. Hybrid inorganic-organic adsorbents Part 1: Synthesis and characterization of mesoporous zirconium titanate frameworks containing coordinating organic functionalities.
Science.gov (United States)
Griffith, Christopher S; De Los Reyes, Massey; Scales, Nicholas; Hanna, John V; Luca, Vittorio
2010-12-01
A series of functional hybrid inorganic-organic adsorbent materials have been prepared through postsynthetic grafting of mesoporous zirconium titanate xerogel powders using a range of synthesized and commercial mono-, bis-, and tris-phosphonic acids, many of which have never before been investigated for the preparation of hybrid phases. The hybrid materials have been characterized using thermogravimetric analysis, diffuse reflectance infrared (DRIFT) and 31P MAS NMR spectroscopic techniques and their adsorption properties studied using a 153Gd radiotracer. The highest level of surface functionalization (molecules/nm2) was observed for methylphosphonic acid (∼3 molecules/nm2). The level of functionalization decreased with an increase in the number of potential surface coordinating groups of the phosphonic acids. Spectral decomposition of the DRIFT and 31P MAS NMR spectra showed that each of the phosphonic acid molecules coordinated strongly to the metal oxide surface but that for the 1,1-bis-phosphonic acids and tris-phosphonic acids the coordination was highly variable resulting in a proportion of free or loosely coordinated phosphonic acid groups. Functionalization of a porous mixed metal oxide framework with the tris-methylenephosphonic acid (ATMP-ZrTi-0.33) resulted in a hybrid with the highest affinity for 153Gd3+ in nitric acid solutions across a wide range of acid concentrations. The ATMP-ZrTi-0.33 hybrid material extracted 153Gd3+ with a Kd value of 1×10(4) in 0.01 M HNO3 far exceeding that of the other hybrid phases. The unfunctionalized mesoporous mixed metal oxide had negligible affinity for Gd3+ (Kdcapacity of the ATMP-ZrTi-0.33 hybrid phase for Gd3+ has been determined to be about 0.005 mmol/g in 0.01 M HNO3. This behavior and that of the other hybrid phases suggests that the surface-bound ATMP ligand functions as a chelating ligand toward 153Gd3+ under these acidic conditions. PMID:21073158
13. Two-Factor Model of Soil Suction from Capillarity, Shrinkage, Adsorbed Film, and Intra-aggregate Structure
CERN Document Server
Chertkov, V Y
2014-01-01
The objective of this work is to derive the soil water retention from the soil structure without curve-fitting and only using the physical parameters found irrespective of an experimental retention curve. Two key points underlie the work: (i) the soil suction at drying coincides with that of the soil intra-aggregate matrix and contributive clay; and (ii) both the soil suction and volume shrinkage at drying depend on the same soil water content. In addition the two following results are used: (i) the available two-factor (capillarity and shrinkage) model of clay suction enables one to connect a clay suction and clay water content using the clay matrix structure; and (ii) the recent reference shrinkage curve model based on the concepts of intra-aggregate soil structure permits one to connect the soil water content at shrinkage with the water content of the contributive clay. With that the available two-factor model was essentially modified and, in particular, the effect of adsorbed water film was taken into acc...
14. Magnetic niobia as adsorbent of organic contaminants in aqueous medium: effect of temperature and pH
International Nuclear Information System (INIS)
This work describes novel materials based on pure iron oxide and iron oxide/niobia composite to produce a magnetic adsorbent. These materials were prepared with synthetic iron oxide and characterized by powder XRD, SEM, FTIR, TPR and Moessbauer spectroscopy. Results showed that the main iron oxides formed were goethite (α FeOOH) and maghemite (γFe2O3) with small particle size. The iron oxide and iron oxide/niobia composite showed high adsorption ability for organic compounds. The positive enthalpy indicated an endothermic adsorption process suggesting physical adsorption. (author)
15. A New Experimental Method to Determine the Henry’s Law Constant of a Volatile Organic Compound Adsorbed in Soil
OpenAIRE
2015-01-01
This paper presents a new mechanical method to determine Henry’s law constant (HLC) of a volatile organic compound (VOC). This method is an extension of the one proposed by Ouoba et al. (2010) to determine the water activity in porous media. This work focuses on TCE and aims at characterizing its liquid-vapor equilibrium in various cases in the form of a pure liquid phase or dissolved in an aqueous solution, adsorbed or not in a natural soil. A liquid phase is disposed in a closed chamber who...
16. Tribochemical synthesis of nano-lubricant films from adsorbed molecules at sliding solid interface: Tribo-polymers from α-pinene, pinane, and n-decane
Science.gov (United States)
He, Xin; Barthel, Anthony J.; Kim, Seong H.
2016-06-01
The mechanochemical reactions of adsorbed molecules at sliding interfaces were studied for α-pinene (C10H16), pinane (C10H18), and n-decane (C10H22) on a stainless steel substrate surface. During vapor phase lubrication, molecules adsorbed at the sliding interface could be activated by mechanical shear. Under the equilibrium adsorption condition of these molecules, the friction coefficient of sliding steel surfaces was about 0.2 and a polymeric film was tribochemically produced. The synthesis yield of α-pinene tribo-polymers was about twice as much as pinane tribo-polymers. In contrast to these strained bicyclic hydrocarbons, n-decane showed much weaker activity for tribo-polymerization at the same mechanical shear condition. These results suggested that the mechanical shear at tribological interfaces could induce the opening of the strained ring structure of α-pinene and pinane, which leads to polymerization of adsorbed molecules at the sliding track. On a stainless steel surface, such polymerization reactions of adsorbed molecules do not occur under typical surface reaction conditions. The mechanical properties and boundary lubrication efficiency of the produced tribo-polymer films are discussed.
17. An investigation of the sorption/desorption of organics from natural waters by solid adsorbents and anion exchangers
International Nuclear Information System (INIS)
The results of laboratory and operational tests at thermal and nuclear power stations on anion exchangers and solid adsorbents of makeup water treatment plants with regard to the sorption/desorption of organic substances in natural water and condensate are presented. The resins Amberlite trademark IRA-67, IRA-900, IRA-958Cl, Purolite registered 2 A-500P, DowexTM3 Marathon, and others were tested. Retention of up to 60-80% of the ''organic'' material on the anion exchangers and organic absorbers installed at different places in the technological scheme of the water processing unit was attained. The possibility of a partial ''poisoning'' of the resins and the degradation of the working characteristics over the first year of operation are discussed. (orig.)
18. Uenbinding'' an adsorbed organic molecule: K plus PTCDA on Ag(110)
Energy Technology Data Exchange (ETDEWEB)
Bauer, Oliver; Schmitz, Christoph H.; Fiedler, Benjamin; Sokolowski, Moritz [Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn (Germany); Mercurio, Giuseppe; Subach, Sergey; Tautz, Frank Stefan [Institut fuer Bio- und Nanosysteme 3, Forschungszentrum Juelich (Germany)
2010-07-01
We have doped the well-known brick-wall structure of pristine PTCDA which is present in the monolayer on the Ag(110) surface with potassium (K) and investigated the induced structural and electronic changes at the interface. SPA-LEED measurements reveal that the structural order of the PTCDA molecules is strongly altered upon K dosing: A variety of co-existing binary phases is observed within the monolayer. In addition we have conducted XPS and NIXSW measurements on K+PTCDA/Ag(110). The photoemission experiments indicate that the K atoms preferentially interact with the carboxylic groups of the co-adsorbed PTCDA molecules. This interpretation is further supported by the NIXSW results: The adsorption geometries of the carboxylic and the anhydride oxygen (O) atoms are highly influenced by the presence of K on the surface, the bonding distances are extended. The adsorption height of the perylene core is also increased by K doping. Hence we conclude that the local Ag-O bonds at the interface are partially lifted by the co-adsorbed K and that K and Ag atoms compete for the interaction with the carboxylic groups of PTCDA while the bonding across the interface is weakened.
19. Effects of molecule-insulator interaction on geometric property of a single phthalocyanine molecule adsorbed on an ultrathin NaCl film
Science.gov (United States)
Miwa, Kuniyuki; Imada, Hiroshi; Kawahara, Shota; Kim, Yousoo
2016-04-01
The adsorption structure and orientation of a metal-free phthalocyanine (H2Pc ) and a magnesium phthalocyanine (MgPc) on a bilayer of NaCl films were investigated both theoretically and experimentally by means of first-principles calculations based on density functional theory and by scanning tunneling microscopy. H2Pc is adsorbed with its center over the sodium cation, and H-N bonds in the molecule are aligned with the [100] or [010] surface direction of a bilayer (001)-terminated NaCl film. The most stable structures of MgPc on the NaCl film show two kinds of orientations corresponding to the molecule rotated by ±7∘ relative to the [110] surface direction, with the Mg cation positioned over the chlorine anion in both cases. The energetic barrier for switching between these orientations is as low as 9.0 meV, and during an STM measurement, an orientational change of MgPc can be observed. The interaction between the adsorbed molecule and the NaCl film were analyzed in terms of dispersion interaction, Mg-Cl chemical bonding, and electrostatic interaction. It is found that the small electrostatic interaction between the molecule and the film gives a dominant contribution to determining the molecular orientation. Our detailed and comprehensive studies of the molecule-insulator interaction will provide knowledge to understand and control the properties of molecules on an insulating material.
20. Organic thin films and surfaces directions for the nineties
CERN Document Server
Ulman, Abraham
1995-01-01
Physics of Thin Films has been one of the longest running continuing series in thin film science consisting of 20 volumes since 1963. The series contains some of the highest quality studies of the properties ofvarious thin films materials and systems.In order to be able to reflect the development of todays science and to cover all modern aspects of thin films, the series, beginning with Volume 20, will move beyond the basic physics of thin films. It will address the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Ther
1. Mixture diffusion of adsorbed organic compounds in metal-organic frameworks as studied by magic-angle spinning pulsed-field gradient nuclear magnetic resonance
International Nuclear Information System (INIS)
The magic-angle spinning (MAS) and pulsed-field gradient nuclear magnetic resonance (PFG NMR) techniques have been combined using a commercially available microimaging system providing a gradient in the magic-angle direction of up to ±2.6 T m-1, together with a narrow bore MAS probe. By narrowing the spectral linewidths, detection of the single and mixed molecular species adsorbed in porous material and their respective mobilities becomes possible. Here, we report on protocols for MAS PFG NMR measurements, new methods for the indispensable sample alignment along the MAS rotational axis and gradient direction and first experimental results of diffusion studies on n-hexane and benzene adsorbed in the metal-organic framework MOF-5.
2. Ultrathin organic semiconductor films--soft matter effect.
Science.gov (United States)
Wang, Tong; Yan, Donghang
2014-05-01
The growth of organic semiconductor thin films has been a crucial issue in organic electronics, especially the growth at the early stages. The thin-film phase has been found to be a common phenomenon in many organic semiconductor thin films, which is closely related with the weak van der Waals interaction between organic molecules, the long-range interaction between organic molecules and the substrate, as well as the soft matter characteristics of ultrathin films. The growth behavior and soft matter characteristics of the thin-film phase have great effects on thin film morphology and structure, for example, the formation and coalescence of grain boundaries, which further influences the performance of organic electronic devices. The understanding of thin-film phase and its intrinsic quality is necessary for fabricating large-size, highly ordered, continuous and defect-free ultrathin films. This review will focus on the growth behavior of organic ultrathin films, i.e., the level of the first several molecular layers, and provide an overview of the soft matter characteristics. PMID:24548597
3. Linear and nonlinear surface spectroscopy of supported size selected metal clusters and organic adsorbates
Energy Technology Data Exchange (ETDEWEB)
Thaemer, Martin Georg
2012-03-08
The spectroscopic investigation of supported size selected metal clusters over a wide wavelength range plays an important role for understanding their outstanding catalytic properties. The challenge which must be overcome to perform such measurements is the difficult detection of the weak spectroscopic signals from these samples. As a consequence, highly sensitive spectroscopic methods are applied, such as surface Cavity Ringdown Spectroscopy and surface Second Harmonic Generation Spectroscopy. The spectroscopic apparatus developed is shown to have a sensitivity which is high enough to detect sub-monolayer coverages of adsorbates on surfaces. In the measured spectra of small supported silver clusters of the sizes Ag{sub 4}2, Ag{sub 2}1, Ag{sub 9}, and Ag atoms a stepwise transition from particles with purely metallic character to particles with molecule-like properties can be observed within this size range.
4. Structure and spectroscopy of hydrogen adsorbed in a nickel metal–organic framework
International Nuclear Information System (INIS)
Highlights: • D2 adsorbed in Ni2(dobdc) exhibits a close metal-D2 distance of 2.20(1) Å. • H2 quantum rotational levels determined for 3 adsorption sites. • Layering of H2 over D2 reveal the transitions of H2 at the second adsorption site. - Abstract: The structure of Ni2(dobdc) (dobdc4− = 2,5-dioxido-1,4-benzenedicarboxylate) as a function of deuterium adsorption has been determined through the application of in situ neutron powder diffraction. Detailed information concerning the local adsorption potential for hydrogen at each site has also been probed using inelastic neutron scattering techniques. These results are compared to those previously published on isostructural analogs and the Ni2+ variant shows the shortest deuterium-metal distance in the M2(dobdc) series (M = Mg, Zn, Co, Fe) that have been studied so far
5. Multilayer bonding using a conformal adsorbate film (CAF) for the fabrication of 3D monolithic microfluidic devices in photopolymer
International Nuclear Information System (INIS)
Reliable microfabrication processes and materials compatible with complementary metal-oxide semiconductor (CMOS) technology are required by industry for the mass production of complex and highly miniaturized lab-on-a-chip systems. Photopolymers are commonly used in the semiconductor industry, and are suitable for the integration of multilayer structures onto CMOS substrates. This paper describes a novel photopolymer bonding process compatible with CMOS technology for the fabrication of three-dimensional monolithic microfluidic devices. The process consists of the formation of a conformal adsorbate film (CAF) approximately 15 nm thick on a patterned photopolymer layer (KMPR), thereby increasing the number of open polymer chains at the bonding interface and acting as an ultra-thin adhesive layer. This thin adhesive layer is made of the same photopolymer as the microfluidic structures, but has a substantially lower crosslinking density so it will be able to make better bonds during a thermocompressive bonding step. This CAF treatment substantially improves the bonding yield between two patterned and previously crosslinked photopolymer layers because both optimum structure strength (to resist deformation during bonding) and bonding strength from epoxy crosslinking can be achieved. We demonstrate high bonding yields of up to 99% of the useful area of the substrate after three successive bonding steps. With this technique, up to six layers have been bonded in a single device. Unlike previously reported methods the quality of bonding is mostly decoupled from soft-bake parameters and crosslinking level of the previously patterned layers. Three differentbonding processes were characterized to describe the bonding mechanism and the differences between the presented method and the partial-crosslinking bonding method. Capillary filling experiments were performed in microchannels of multilayer structures built with the CAF technique, without any observable leakage between
6. Removing organic contaminants with bifunctional iron modified rectorite as efficient adsorbent and visible light photo-Fenton catalyst
International Nuclear Information System (INIS)
Highlights: ► Rectorite was modified by ultrasonic-assisted ion-exchange and hydrolysis. ► The pillaring increased the layer-to-layer spacing of rectorite. ► The iron-modified rectorite was found to be an excellent adsorbent. ► The iron-modified rectorite showed good visible light photocatalytic ability. ► FeR was highly chemically stable with a wide operating range of pH. - Abstract: Iron-modified rectorite (FeR) was prepared as both adsorbent and catalyst. The iron modification increased layer-to-layer spacing and surface area of rectorite, leading to much increased adsorption of Rhodamine B (RhB) on rectorite. The maximum adsorption capacity of RhB on FeR reached 101 mg g−1 at pH 4.5, being 11 folds of that on the unmodified one. The iron modification also enabled rectorite to have efficient visible light photocatalytic ability. The apparent rate constant for the degradation of RhB (80 μM) at 298 K and pH 4.5 in the presence of H2O2 (6.0 mM) and FeR (0.4 g L−1) was evaluated to be 0.0413 min−1 under visible light and 0.122 min−1 under sunlight, respectively. The analysis with electron spin resonance spin-trapping technique supported that the iron modified rectorite effectively catalyzed the decomposition of H2O2 into hydroxyl radicals. On the basis of the characterization and analysis, the new bifunctional material was well clarified as both adsorbent and photocatalyst in the removing of organic pollutants.
7. Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine
International Nuclear Information System (INIS)
Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency
8. Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine
Energy Technology Data Exchange (ETDEWEB)
Lin, Kun-Yi Andrew, E-mail: [email protected] [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Chen, Shen-Yi [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Jochems, Andrew P. [New Mexico Bureau of Geology & Mineral Resources and New Mexico Institute of Mining & Technology, Socorro, NM (United States)
2015-06-15
Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency.
9. Removal of hexenuronic acid by xylanase to reduce adsorbable organic halides formation in chlorine dioxide bleaching of bagasse pulp.
Science.gov (United States)
Nie, Shuangxi; Wang, Shuangfei; Qin, Chengrong; Yao, Shuangquan; Ebonka, Johnbull Friday; Song, Xueping; Li, Kecheng
2015-11-01
Xylanase-aided chlorine dioxide bleaching of bagasse pulp was investigated. The pulp was pretreated with xylanase and followed a chlorine dioxide bleaching stage. The ATR-FTIR and XPS were employed to determine the surface chemistry of the control pulp, xylanase treated and chlorine dioxide treated pulps. The hexenuronic acid (HexA) could obviously be reduced after xylanase pretreatment, and the adsorbable organic halides (AOX) were reduced after chlorine dioxide bleaching. Compared to the control pulp, AOX could be reduced by 21.4-26.6% with xylanase treatment. Chlorine dioxide demand could be reduced by 12.5-22% to achieve the same brightness. The ATR-FTIR and XPS results showed that lignin and hemicellulose (mainly HexA) were the main source for AOX formation. Xylanase pretreatment could remove HexA and expose more lignin, which decreased the chlorine dioxide demand and thus reduced formation of AOX. PMID:26263004
10. Biogas from MSW landfill: Composition and determination of chlorine content with the AOX (adsorbable organically bound halogens) technique
International Nuclear Information System (INIS)
An exhaustive characterization of the biogas from some waste disposal facilities has been carried out. The analysis includes the main components (methane, carbon dioxide, nitrogen and oxygen) as well as trace components such as hydrogen sulphide, ammonia and VOCs (volatile organic compounds) including siloxanes and halogenated compounds. VOCs were measured by GC/MS (Gas Chromatography/Mass Spectrometry) using two different procedures: thermal desorption of the Tenax TA and Carbotrap 349 tubes and SPME (Solid Phase Micro-Extraction). A method has been established to measure the total halogen content of the biogas with the AOX (adsorbable organically bound halogens) technique. The equipment used to analyze the samples was a Total Organic Halogen Analyzer (TOX-100). Similar results were obtained when comparing the TOX (Total Organic Halogen) values with those obtained by GC/MS. The halogen content in all the samples was under 22 mg Cl/Nm3 which is below the limit of 150 mg/Nm3 proposed in the Spanish Regulations for any use of the biogas. The low chlorine content in the biogas studied, as well as the low content of other trace compounds, makes it suitable for use as a fuel for electricity generating engines
11. Fluorescent thin gel films using organic dyes and pigments
Science.gov (United States)
Nakazumi, Hiroyuki; Takashi, Tarao; Taniguchi, Shin-ichi; Nanto, Hidehito
1997-10-01
New organic-inorganic fluorescent thin gel films included with laser dyes or fluorescent organic pigments have been prepared for display application. The florescent dyes (benzoxazolium, pyrromethene, and rhodamine dyes) and super-fine particles of fluorescent pigments (coumarin and perylene) were successfully incorporated into thin silicate gel films prepared from tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), and methoxysilane oligomer (MTSO) under acid catalyzed hydrolysis. The blue, green, and red luminescence were observed from these thin films (thickness: 100 - 400 nm), respectively. Fluorescence spectra, fluorescent quantum yield and lifetime of thin gel films are examined. Fluorescent peaks for most of dyes and pigments used in gel films were similar to those in solution, and fluorescent lifetime for dyes and pigments used in gel films were 2.9 - 4.5 ns. Photostability of fluorescent gel films is dependent on fluorescent organic dyes and pigments used and/or silicate gel matrixes. Coumarin and perylene pigments have higher fluorescent quantum yield in gel film prepared from MTSO. The large Stokes shift was observed in fluorescent gel film using coumarin and benzoxazolium dyes. The coumarin and perylene pigments are significantly photo- stable in gel film prepared from MTSO, and photodegradation of perylene red after irradiation of 500 W Xi-lamp for 30 min is below 20%.
12. Prediction of capacity factors for aqueous organic solutes adsorbed on a porous acrylic resin
Science.gov (United States)
Thurman, E.M.
1978-01-01
The capacity factors of 20 aromatic, allphatic, and allcycllc organic solutes with carboxyl, hydroxyl, amine, and methyl functional groups were determined on Amberlite XAD-8, a porous acrylic resin. The logarithm of the capacity factor, k???, correlated inversely with the logarithm of the aqueous molar solubility with significance of less than 0.001. The log k???-log solubility relationship may be used to predict the capacity of any organic solute for XAD-8 using only the solubility of the solute. The prediction is useful as a guide for determining the proper ratio of sample to column size In the preconcentration of organic solutes from water. The inverse relationship of solubility and capacity is due to the unfavorable entropy of solution of organic solutes which affects both solubility and sorption.
13. Studying of kinetic growth of organic thin films
Directory of Open Access Journals (Sweden)
J.P. Weszka
2009-07-01
Full Text Available Purpose: of this paper: Studying of growth kinetic of organic thin film prepared by vacuum thermal evaporation technology.Design/methodology/approach: Applying of quartz crystal microbalance to thickness control of organic thin films deposition process.Findings: Results of this issue suggesting that the kinetics of organic thin films is depending of current flowing through the crucible (crucible temperature.Research limitations/implications: Kinetics of vacuum evaporation of thin film is different from that of inorganic thin films during the growth process.Practical implications: The means of connect the quartz crystal microbalance MSV 1843/AB with vacuum chamber, function and means of thickness and deposition rate measuring has been described. This scientific paper include also description of researching results of kinetics of organic and metallic thin film evaporation process by MSV 1843/AB quartz crystal microbalance and verification these results by comparing them with results from other measuring techniques.Originality/value: Controlling thickness of thermally evaporated organic thin film during the film growth process.
14. Techniques expérimentales pour l'étude des films monomoléculaires adsorbés sur un substrat Experimental Techniques for Analysing the Monomolecular Films Absorbed on a Substrate
Directory of Open Access Journals (Sweden)
Jacquet M.
2006-11-01
Full Text Available Cet article a pour but de donner un aperçu des différentes méthodes les plus couramment utilisées dans l'étude des films monomoléculaires adsorbés sur un substrat massif et d'orienter l'utilisateur vers l'une ou l'autre de ces méthodes. Pour chacune d'elles, le fondement théorique, l'information fournie et la sensibilité de la mesure sont précisés. Une des difficultés réside dans le fait que les échantillons utilisés sont massifs et que les quantités adsorbées mises en jeu sont de ce fait toujours extrêmement petites. The aim of this article is to toke a look at the different methods most commonly used for analyzing the monomolecular films adsorbed on a massive substrate and to guide users toward one or another of these methods. For each of them, the theoretical validity, the information available and the measurement sensitivity are given. One of the difficulties lies in the fact that the samples used are massive and the adsorbed amounts involved are hence always extremely minute.
15. Electrochemical Behavior of Organic Film With Nano Silica
Institute of Scientific and Technical Information of China (English)
GONG Li; LU Tan-ping
2004-01-01
Organic-inorganic composite films were prepared by adding different amount of nano-SiO2into water soluble acrylic resin (AC) on hot-dip galvanized steel sheet. The electrochemical behavior of nano SiO2 modified acrylic resin films in 5 % NaCl solution were studied by electrochemical measurement techniques. Results indicate when there are 8% ～ 12% SiO2 in organic film, it can shows an analogous passivation propertyin anodic polarization curves, increase anodic polarization function of galvanized coating, retarde lectrode reaction more efficiently. The reason is that either SiO2 in organic film occur chemical reaction with Zn, produce stable zinc silicate compound; or as aresult of dissolve-redeposit of SiO2 in the film.
16. Advanced Structural Characterization of Organic Thin Films
DEFF Research Database (Denmark)
Gu, Yun
of small molecule and polymer layers is indicated by Flory- Huggins theory for the triisopropylsilylethynl pentacene (TIPS-PEN) and polystyrene blend films. In order to investigate the phase separated layers in the ink-jet printed films, we propose a method to measure diraction Bragg peaks by X...
17. Characterization of interfaces between metals and organic thin films by electron and ion spectroscopies
Energy Technology Data Exchange (ETDEWEB)
Schmid, Martin
2012-01-18
In this thesis, interfaces between metals and organic thin films have been characterized with photoelectron and ion-scattering spectroscopies. Two different classes of metal/organic interfaces were examined in detail. First, interfaces which can be mainly characterized by relatively weak coordinative interactions between substrate and adsorbate. Second, interfaces which are mostly determined, or even created, by chemical reactions between different adsorbates or between adsorbates and substrate. Typical examples from the first class are metalated tetrapyrrole monolayers on Ag(111) and Au(111) single-crystal substrates. In this study, a focus was set to the interaction between iron and cobalt tetrapyrroles with Ag(111) or Au(111) substrates. A detailed examination of the corresponding photoelectron spectra revealed that the adsorbatesubstrate interaction is associated with a charge transfer from the metallic substrate to the Fe(II) or Co(II) ions within the tetrapyrrole units. The examination of cobalt(II) phthalocyanine monolayers further led to the conclusion that the magnetic moment, as present in unperturbed CoPc molecules, is efficiently quenched by the contact to the Ag(111) surface and the associated charge transfer. Similar investigations on Au(111) substrates gave evidence for possible adsorption site effects, further complicating the adsorbate/substrate interaction. Furthermore the formation of two-dimensional structures of poly(p-phenylene-terephthalamide) (PPTA, trademark Kevlar) on Ag(111) was closely examined. The Ag(111) surface does not only provide the geometrical boundary for the formation of the 2D covalent structures, but, moreover, actively participates in the reaction; after the adsorption of TPC molecules, a scission of the C-Cl bond, in particular at temperatures above 120 K, was evident. The resulting radical fragments appear stable and can act as reaction partners for the co-adsorbed PPD units. The chlorine atoms reside on the surface even
18. AMBIENT LEVEL VOLATILE ORGANIC COMPOUND (VOC) MONITORING USING SOLID ADSORBANTS - RECENT U.S. EPA STUDIES
Science.gov (United States)
Ambient air spiked with 1-10 ppbv concentrations of 41 toxic volatile organic compounds (VOCs) listed in U.S. Environmental Protection Agency (EPA) Compendium Method TO-14A was monitored using solid sorbents for sample collection and a Varian Saturn 2000 ion trap mass spectrome...
19. Composition of Organic Compounds Adsorbed on PM10 in the Air Above Maribor.
Science.gov (United States)
Miuc, Alen; Vončina, Ernest; Lečnik, Uroš
2015-01-01
Organic compounds in atmospheric particulate matterabove Maribor were analysed in 120 samples of PM10 sampled according to the EN 12341:2014 reference method. Organic compounds compositions were investigated together with the primary and secondary sources of air pollution. Silylation as derivatisation method was used for the GC/MS determination of volatile and semi-volatile polar organic compounds. Distribution of fatty acids, n-alkanes and iso-alkanes, phthalate esters, siloxanes, different sterols, various sugars and sugar alcohols, compounds of lignin and resin acids, dicarboxylic acids from photochemical reactions, PAHs, organic nitrogen compounds and products from secondary oxidation of monoterpenes were determined. The use of silicone grease for the purpose of lubricating the impact surface of the air sampler caused higher values of gravimetric determination. Solid particles may have been bounced from the surface of a greasy impact plate and re-entrained within the air stream and then collected on a sample filter. The carryover of siloxanes was at least from 5% up to 15% of the accumulated particles weight, depending on ambient temperature. This was the reason that the gravimetric results for determination of PM10 according to the standard EN 12341:2014 were overestimated. PMID:26680711
20. A Neutron-Diffraction Study of the Solid Layers at the Liquid Solid Boundary in 4He-Films Adsorbed on Graphite
DEFF Research Database (Denmark)
da Costa Carneiro, Kim; Passell, L.; Thomlinson, W.;
1981-01-01
A neutron scattering study of the structure of 4He films adsorbed on graphite is reported. Diffraction from helium monolayers at a temperature of 1.2K shows the formation of an incommensurate, triangular-lattice solid of high density. As the coverage is increased above two layers, the diffraction...... pattern changes indicating solidification of a second layer. The observed two-layer patterns can be indexed with either a pair of incommensurate, triangular-lattice solid layers of different densities or a close-packed bilayer; the experimental information available is not sufficient to make a more...
1. Fabrication and characterization of advanced Organic Thin Film Transistors
OpenAIRE
Scaldaferri, Rossana
2009-01-01
The thesis aims to the development of Organic Thin Film Transistors and more complex devices based on organic materials. The experimental work demonstrates the possibility to manufacture transistors and more complex circuits with innovative polymers and technologies, leading to an experimental validation of the possibility to realize all-organic devices.
2. Removal of methylene blue from aqueous solutions by an adsorbent based on metal-organic framework and polyoxometalate
International Nuclear Information System (INIS)
A metal-organic framework (Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate) composite based on polyoxometalate (H6P2W18O62) was synthesized by a simple one-pot solvent-thermal method and applied as an adsorbent to remove methylene blue (MB) from aqueous solution. The chemical structure, morphology and thermostability of the composite were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TG) and N2 adsorption–desorption isotherms. The removal rate of the composite H6P2W18O62@Cu3(BTC)2 was greater than that of the pure Cu3(BTC)2, especially at higher initial concentrations, showing that the adsorption performance of porous Cu3(BTC)2 can be improved through the modification of H6P2W18O62. The effect factors containing the initial concentration, contact time, initial solution pH and temperature of MB adsorption onto the composite were systematically explored. The experimental isotherm data was found to fit the Freundlich model well and the process of MB adsorption onto H6P2W18O62@Cu3(BTC)2 was controlled by the pseudo-second-order kinetic model. The thermodynamic parameters illustrated that the adsorption was spontaneous and exothermic process. These results show that designing a metal-organic framework composite is a quite promising strategy to achieve extreme application for metal-organic framework. - Graphical abstract: Comparison of removal rate for MB in pure Cu3(BTC)2 and H6P2W18O62@Cu3(BTC)2 at different initial concentration. - Highlights: • Metal-organic framework (MOF) composite in the adsorption application was proposed. • The adsorption rate of MOF was improved by introducing polyoxometalates. • The adsorption isotherm and kinetic was used to describe the adsorption mechanism. • The thermodynamic parameters on the composite were thoroughly investigated
3. Organic nanostructured thin film devices and coatings for clean energy
CERN Document Server
Zhang, Sam
2010-01-01
Authored by leading experts from around the world, the three-volume Handbook of Nanostructured Thin Films and Coatings gives scientific researchers and product engineers a resource as dynamic and flexible as the field itself. The first two volumes cover the latest research and application of the mechanical and functional properties of thin films and coatings, while the third volume explores the cutting-edge organic nanostructured devices used to produce clean energy. This third volume, Organic Nanostructured Thin Film Devices and Coatings for Clean Energy, addresses various aspects of the proc
4. Thin-film organic photonics molecular layer deposition and applications
CERN Document Server
Yoshimura, Tetsuzo
2011-01-01
Among the many atomic/molecular assembling techniques used to develop artificial materials, molecular layer deposition (MLD) continues to receive special attention as the next-generation growth technique for organic thin-film materials used in photonics and electronics. Thin-Film Organic Photonics: Molecular Layer Deposition and Applications describes how photonic/electronic properties of thin films can be improved through MLD, which enables precise control of atomic and molecular arrangements to construct a wire network that achieves ""three-dimensional growth"". MLD facilitates dot-by-dot--o
5. Mechanisms of Heat Transfer in Porous Crystals Containing Adsorbed Gases: Applications to Metal-Organic Frameworks
Science.gov (United States)
Babaei, Hasan; Wilmer, Christopher E.
2016-01-01
We have studied the mechanisms of heat transfer in a porous crystal-gas mixture system, motivated by the not insignificant challenge of quickly dissipating heat generated in metal-organic frameworks (MOFs) due to gas adsorption. Our study reveals that the thermal conductance of the system (crystal and gas) is dominated by lattice thermal conductivity in the crystal, and that conductance is reduced as the concentration of gas in the pores increases. This mechanism was observed from classical molecular simulations of a monatomic gas in an idealized porous crystal structure. We show that the decreased conductivity associated with increased gas concentration is due to phonon scattering in the crystal due to interactions with gas molecules. Calculations of scattering rates for two phonon modes reveal that scattering of the lowest frequency mode scales linearly with gas density. This result suggests that the probability of a phonon-gas collision is simply proportional to the number of gas molecules in the pore.
6. Femtomagnetism in graphene induced by core level excitation of organic adsorbates
Science.gov (United States)
Ravikumar, Abhilash; Baby, Anu; Lin, He; Brivio, Gian Paolo; Fratesi, Guido
2016-01-01
We predict the induction or suppression of magnetism in the valence shell of physisorbed and chemisorbed organic molecules on graphene occurring on the femtosecond time scale as a result of core level excitations. For physisorbed molecules, where the interaction with graphene is dominated by van der Waals forces and the system is non-magnetic in the ground state, numerical simulations based on density functional theory show that the valence electrons relax towards a spin polarized configuration upon excitation of a core-level electron. The magnetism depends on efficient electron transfer from graphene on the femtosecond time scale. On the other hand, when graphene is covalently functionalized, the system is magnetic in the ground state showing two spin dependent mid gap states localized around the adsorption site. At variance with the physisorbed case upon core-level excitation, the LUMO of the molecule and the mid gap states of graphene hybridize and the relaxed valence shell is not magnetic anymore. PMID:27089847
7. Tunneling spectroscopy of highly ordered organic thin films
OpenAIRE
Törker, Michael
2003-01-01
In this work, a Au(100) single crystal was used as substrate for organic molecular beam epitaxy. Highly ordered organic thin films of the molecules 3,4,9,10-perylenetetracarboxylic-3,4,9,10-dianhydrid (PTCDA) and hexa-peri-hexabenzo-coronene (HBC) as well as organic-organic heterostructures on reconstructed Au(100) were prepared. The molecular arrangement was characterized in Scanning Tunneling Microscopy and Low Energy Electron Diffraction investigations. Scanning Tunneling Spectroscopy data...
8. NMR Study of HD Adsorbed in a Z-type Metal-Organic Framework
International Nuclear Information System (INIS)
We report the results of measurements of the nuclear spin-lattice and spin-spin relaxation rates of hydrogen deuteride trapped in the mesoporous cages of a metal organic framework (MOF) for temperatures 2.2 < T < 50 K There is considerable interest in the use of this class of materials for hydrogen storage because of the high density of adsorption. NMR studies can provide important information about the molecular interactions and dynamics inside the cages of the MOF structure. Samples were studied with filling factors of 0.1 and 1.0 molecules per cage as determined by the adsorption isotherm at 77 K The results show strong peaks in the relaxation times at several well defined temperatures that are very different from the adsorption energy levels. The origin of these peaks is discussed in terms of the quantization of the translational degrees of freedom of the molecules inside the cages and the associated discrete energy levels. Measurements of the nuclear spin-spin relaxation times also provide an important measure of the diffusivity of hydrogen through the MOF structure which is a critical parameter for the use of MOFs for storage and transport.
9. Aluminium fumarate metal-organic framework: A super adsorbent for fluoride from water.
Science.gov (United States)
Karmakar, Sankha; Dechnik, Janina; Janiak, Christoph; De, Sirshendu
2016-02-13
Potential of aluminium fumarate metal organic framework (MOF) for fluoride removal from groundwater has been explored in this work. The laboratory produced MOF exhibited characteristics similar to the commercial version. MOF was found to be micro-porous with surface area of 1156 m(2)/g and average pore size 17Å. Scanning electron micrograph of the AlFu MOF showed minute pores and texture was completely different from either of the parent materials. Change in the composition of AlFu MOF after fluoride adsorption was evident from powder X-ray diffraction analysis. Thermal stability of the AlFu MOF up to 700K was established by thermo-gravimetric analysis. Incorporation of fluoride phase after adsorption was confirmed by X-ray fluorescence analysis. As observed from FTIR study, hydroxyl ions in AlFu MOF were substituted by fluoride. 0.75 g/l AlFu MOF was good enough for complete removal of 30 mg/l fluoride concentration in feed solution. The maximum adsorption capacity for fluoride was 600, 550, 504 and 431 mg/g, respectively, at 293, 303, 313 and 333K. PMID:26513559
10. Preparation and characterization of humic acid-carbon hybrid materials as adsorbents for organic micro-pollutants.
Science.gov (United States)
Radwan, Emad K; Abdel Ghafar, Hany H; Moursy, Ahmed S; Langford, Cooper H; Bedair, Ahmed H; Achari, Gopal
2015-08-01
The present work involves the preparation of novel adsorbent materials by the insolubilization and hybridization of humic acid (HA) with carbon. The prepared materials were characterized by N2 adsorption, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, solid-state (13)C cross polarization magic angle spinning nuclear magnetic resonance, and low-field nuclear magnetic resonance (NMR) relaxometry on wetted samples. The water solubility of these materials and the lack of effect of oxidants were also confirmed. With this background, the adsorption capacities toward phenol, 2,4,6-tricholrophenol, and atrazine were evaluated, using these as model compounds for organic micropollutants of concern in water. Experimental results show that the prepared materials are mesoporous and have a higher surface area than humic acid and even than the porous carbon in the case of carbon coating. They retain the basic features of the starting materials with lowered functional group content. Moreover, there are interesting new features. NMR relaxometry shows that equilibration of water uptake is very fast, making use in water simple. They have higher adsorption capacities than the pure materials, and they can be applied under a wide range of environmental conditions. PMID:25874433
11. Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures
Directory of Open Access Journals (Sweden)
Bruno Pignataro
2013-03-01
Full Text Available This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-equilibrium conditions.
12. Reversible CO Scavenging via Adsorbate-Dependent Spin State Transitions in an Iron(II)-Triazolate Metal-Organic Framework.
Science.gov (United States)
Reed, Douglas A; Xiao, Dianne J; Gonzalez, Miguel I; Darago, Lucy E; Herm, Zoey R; Grandjean, Fernande; Long, Jeffrey R
2016-05-01
A new metal-organic framework, Fe-BTTri (Fe3[(Fe4Cl)3(BTTri)8]2·18CH3OH, H3BTTri =1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene)), is found to be highly selective in the adsorption of CO over a variety of other gas molecules, making it extremely effective, for example, in the removal of trace CO from mixtures with H2, N2, and CH4. This framework not only displays significant CO adsorption capacity at very low pressures (1.45 mmol/g at just 100 μbar), but, importantly, also exhibits readily reversible CO binding. Fe-BTTri utilizes a unique spin state change mechanism to bind CO in which the coordinatively unsaturated, high-spin Fe(II) centers of the framework convert to octahedral, low-spin Fe(II) centers upon CO coordination. Desorption of CO converts the Fe(II) sites back to a high-spin ground state, enabling the facile regeneration and recyclability of the material. This spin state change is supported by characterization via infrared spectroscopy, single crystal X-ray analysis, Mössbauer spectroscopy, and magnetic susceptibility measurements. Importantly, the spin state change is selective for CO and is not observed in the presence of other gases, such as H2, N2, CO2, CH4, or other hydrocarbons, resulting in unprecedentedly high selectivities for CO adsorption for use in CO/H2, CO/N2, and CO/CH4 separations and in preferential CO adsorption over typical strongly adsorbing gases like CO2 and ethylene. While adsorbate-induced spin state transitions are well-known in molecular chemistry, particularly for CO, to our knowledge this is the first time such behavior has been observed in a porous material suitable for use in a gas separation process. Potentially, this effect can be extended to selective separations involving other π-acids. PMID:27097297
13. High-resolution ellipsometric study of an n-alkane film, dotriacontane, adsorbed on a SiO2 surface
DEFF Research Database (Denmark)
Volkmann, U.G.; Pino, M.; Altamirano, L.A.;
2002-01-01
alkane/SiO2 interfacial region differs qualitatively from that which occurs in the surface freezing effect at the bulk alkane fluid/vapor interface. In that case, there is again a perpendicular film phase adjacent to the air interface but no parallel film phase intervenes between it and the bulk alkane...... present at higher coverages. In addition, we have performed high-resolution ellipsometry and stray-light measurements on dotriacontane films deposited from solution onto highly oriented pyrolytic graphite substrates. After film deposition, these substrates proved to be less stable in air than SiO2....
14. Electrodeposition of hybrid ZnO/organic dye films
Energy Technology Data Exchange (ETDEWEB)
Moya, Monica; Mari, Bernabe; Mollar, Miquel [Department de Fisica Aplicada-IDF, Universitat Politecnica de Valencia, Cami de Vera s/n, 46022 Valencia (Spain)
2011-06-15
The viability of the electrodeposition as a suitable technique for preparing new porous hybrid materials has been tested in this paper. Hybrid ZnO films with two different organic dyes: Eosin-Y and Tetrasulphonated-Cu-phtalocyanine were prepared. Their physical and chemical properties as well as their dependence on the growth conditions were investigated. It is found that the type of dye has a big influence on the morphology and porosity of hybrid films. Open and connected pores are created in hybrid ZnO/Eosin-Y films while both open and closed pores coexist in hybrid ZnO/Tetrasulfonated-Cu-phthalocyanine. As one of the promising applications of hybrid materials is photovoltaic conversion of sunlight, photoelectrochemical characterization of hybrid films is also reported. Photocurrent generation owing to both contributions ZnO and Eosin-Y is observed in ZnO/Eosin-Y films but no photocurrent has been observed in ZnO/Tetrasulfonated-Cu-phthalocyanine films. SEM micrographs of hybrid ZnO films grown in aqueous bath; (Left) ZnO/Eosin-Y films grown at 70 C, -0.9 V (Right) ZnO/Ts-CuPc films grown at 70 C, -0.9 V. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
15. Falling film evaporators: organic solvent regeneration in nuclear fuel reprocessing
International Nuclear Information System (INIS)
The aim of this work was to improve knowledge about working of falling film evaporators used in nuclear fuel reprocessing plants for organic solvent regeneration. The first part deals with a non evaporation film. An original film thickness measuring technique was used; infrared thermography. It gave indications on hydrodynamics and wave amplitude and pointed out thermocapillary forces to be the cause of bad wetting of the heated wall. By another way we showed that a small slit spacing on the film distributor, an enhanced surface roughness and an important liquid flow rate favour a better wetting. The second part deals with evaporation of a binary solvent mixture. Experiments in an industrial evaporator corroborated the fact that it is essential for the efficiency of the apparatus to work at high flow rates. We propose an over-simple model which can be used to estimate performances of co-current falling film evaporators of the process
16. Langmuir-Blodgett films of molecular organic materials
Energy Technology Data Exchange (ETDEWEB)
Talham, Daniel R; Yamamoto, Takashi [Department of Chemistry, University of Florida, Gainesville, FL 32611-7200 (United States); Meisel, Mark W [Department of Physics, Center for Condensed Matter Science, University of Florida, Gainesville, FL 32611-8440 (United States)], E-mail: [email protected]
2008-05-07
Langmuir-Blodgett methods are perhaps the original approach for achieving controlled deposition of organic thin films. Molecules are first organized into a monolayer array on the surface of water before transfer as a monolayer onto solid supports. Molecular monolayers, multilayers, and multilayered heterostructures can be achieved. The capability of exercising such control over thin film assemblies has attracted materials chemists and physicists to develop Langmuir-Blodgett films for studies on organic conductors, magnets, non-linear optics, rectifiers, and intermolecular electron transfer. This article reviews objectives in each of these areas and selects some specific examples from the literature to highlight the state of the art, mostly from the point of view of the chemical systems that are studied. Mixed organic/inorganic hybrid films represent a new direction for Langmuir-Blodgett films in materials science, combining conventional inorganic solid-state phenomena with the properties of the organic networks, and recent examples, taken principally from the authors' work, are highlighted.
17. Fundamentals of laser-assisted fabrication of inorganic and organic films
DEFF Research Database (Denmark)
Schou, Jørgen
2008-01-01
The standard method for producing films by laser-assisted methods, Pulsed Laser Deposition (PLD) will be reviewed. The films considered are usually inorganic films, but also films of organic materials have been produced. Also the deposition of organic films by MAPLE (Matrix Assisted Pulsed Laser...
18. Thin films by metal-organic precursor plasma spray
International Nuclear Information System (INIS)
While most plasma spray routes to coatings utilize solids as the precursor feedstock, metal-organic precursor plasma spray (MOPPS) is an area that the authors have investigated recently as a novel route to thin film materials. Very thin films are possible via MOPPS and the technology offers the possibility of forming graded structures by metering the liquid feed. The current work employs metal-organic compounds that are liquids at standard temperature-pressure conditions. In addition, these complexes contain chemical functionality that allows straightforward thermolytic transformation to targeted phases of interest. Toward that end, aluminum 3,5-heptanedionate (Al(hd)3), triethylsilane (HSi(C2H5)3 or HSiEt3), and titanium tetrakisdiethylamide (Ti(N(C2H5)2)4 or Ti(NEt2)4) were employed as precursors to aluminum oxide, silicon carbide, and titanium nitride, respectively. In all instances, the liquids contain metal-heteroatom bonds envisioned to provide atomic concentrations of the appropriate reagents at the film growth surface, thus promoting phase formation (e.g., Si-C bond in triethylsilane, Ti-N bond in titanium amide, etc.). Films were deposited using a Sulzer Metco TriplexPro-200 plasma spray system under various experimental conditions using design of experiment principles. Film compositions were analyzed by glazing incidence x-ray diffraction and elemental determination by x-ray spectroscopy. MOPPS films from HSiEt3 showed the formation of SiC phase but Al(hd)3-derived films were amorphous. The Ti(NEt2)4 precursor gave MOPPS films that appear to consist of nanosized splats of TiOCN with spheres of TiO2 anatase. While all films in this study suffered from poor adhesion, it is anticipated that the use of heated substrates will aid in the formation of dense, adherent films.
19. Removal of methylene blue from aqueous solutions by an adsorbent based on metal-organic framework and polyoxometalate
Energy Technology Data Exchange (ETDEWEB)
Liu, Xiaoxia; Luo, Jing; Zhu, Yating; Yang, Yun; Yang, Shuijin, E-mail: [email protected]
2015-11-05
A metal-organic framework (Cu{sub 3}(BTC){sub 2}, BTC = 1,3,5-benzenetricarboxylate) composite based on polyoxometalate (H{sub 6}P{sub 2}W{sub 18}O{sub 62}) was synthesized by a simple one-pot solvent-thermal method and applied as an adsorbent to remove methylene blue (MB) from aqueous solution. The chemical structure, morphology and thermostability of the composite were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TG) and N{sub 2} adsorption–desorption isotherms. The removal rate of the composite H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} was greater than that of the pure Cu{sub 3}(BTC){sub 2}, especially at higher initial concentrations, showing that the adsorption performance of porous Cu{sub 3}(BTC){sub 2} can be improved through the modification of H{sub 6}P{sub 2}W{sub 18}O{sub 62}. The effect factors containing the initial concentration, contact time, initial solution pH and temperature of MB adsorption onto the composite were systematically explored. The experimental isotherm data was found to fit the Freundlich model well and the process of MB adsorption onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} was controlled by the pseudo-second-order kinetic model. The thermodynamic parameters illustrated that the adsorption was spontaneous and exothermic process. These results show that designing a metal-organic framework composite is a quite promising strategy to achieve extreme application for metal-organic framework. - Graphical abstract: Comparison of removal rate for MB in pure Cu{sub 3}(BTC){sub 2} and H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} at different initial concentration. - Highlights: • Metal-organic framework (MOF) composite in the adsorption application was proposed. • The adsorption rate of MOF was improved by introducing polyoxometalates. • The adsorption isotherm and kinetic was used to
20. Liquid crystals for organic thin-film transistors
OpenAIRE
Iino, Hiroaki; Usui, Takayuki; Hanna, Jun-ichi
2015-01-01
Crystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,...
1. Organic Thin-Film Transistor (OTFT-Based Sensors
Directory of Open Access Journals (Sweden)
Daniel Elkington
2014-04-01
Full Text Available Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.
2. Thin film Encapsulations of Flexible Organic Light Emitting Diodes
Directory of Open Access Journals (Sweden)
Tsai Fa-Ta
2016-01-01
Full Text Available Various encapsulated films for flexible organic light emitting diodes (OLEDs were studied in this work, where gas barrier layers including inorganic Al2O3 thin films prepared by atomic layer deposition, organic Parylene C thin films prepared by chemical vapor deposition, and their combination were considered. The transmittance and water vapor transmission rate of the various organic and inorgabic encapsulated films were tested. The effects of the encapsulated films on the luminance and current density of the OLEDs were discussed, and the life time experiments of the OLEDs with these encapsulated films were also conducted. The results showed that the transmittance are acceptable even the PET substrate were coated two Al2O3 and Parylene C layers. The results also indicated the WVTR of the PET substrate improved by coating the barrier layers. In the encapsulation performance, it indicates the OLED with Al2O3 /PET, 1 pair/PET, and 2 pairs/PET presents similarly higher luminance than the other two cases. Although the 1 pair/PET encapsulation behaves a litter better luminance than the 2 pairs/PET encapsulation, the 2 pairs/PET encapsulation has much better life time. The OLED with 2 pairs/PET encapsulation behaves near double life time to the 1 pair encapsulation, and four times to none encapsulation.
3. Chemical Annealing of Zinc Tetraphenylporphyrin Films: Effects on Film Morphology and Organic Photovoltaic Performance
KAUST Repository
Trinh, Cong
2012-07-10
We present a chemical annealing process for organic thin films. In this process, a thin film of a molecular material, such as zinc tetraphenylporphyrin (ZnTPP), is exposed to a vapor of nitrogen-based ligand (e.g., pyrazine, pz, and triazine, tz), forming a film composed of the metal-ligand complex. Fast and quantitative formation of the complex leads to marked changes in the morphology and optical properties of the film. X-ray diffraction studies show that the chemical annealing process converts amorphous ZnTPP films to crystalline ZnTPP•ligand films, whose porphryin planes lie nearly parallel to the substrate (average deviation is 8° for the ZnTPP•pz film). Organic solar cells were prepared with ZnTPP donor and C 60 acceptor layers. Devices were prepared with and without chemical annealing of the ZnTPP layer with a pyrazine ligand. The devices with chemically annealed ZnTPP donor layer show an increase in short-circuit current (J SC) and fill factor (FF) relative to analogous unannealed devices, presumably because of enhanced exciton diffusion length and improved charge conductivity. The open circuit voltages (V OC) of the chemically annealed devices are lower than their unannealed counterpart because of enhanced polaron pair recombination at the donor/acceptor heterojunction. A net improvement of 5-20% in efficiency has been achieved, after chemical annealing of ZnTPP films with pyrazine. © 2012 American Chemical Society.
4. Light trapping in thin film organic solar cells
Directory of Open Access Journals (Sweden)
Zheng Tang
2014-10-01
Full Text Available A major issue in organic solar cells is the poor mobility and recombination of the photogenerated charge carriers. The active layer has to be kept thin to facilitate charge transport and minimize recombination losses. However, optical losses due to inefficient light absorption in the thin active layers can be considerable in organic solar cells. Therefore, light trapping schemes are critically important for efficient organic solar cells. Traditional light trapping schemes for thick solar cells need to be modified for organic thin film solar cells in which coherent optics and wave effects play a significant role. In this review, we discuss the light trapping schemes for organic thin film solar cells, which includes geometric engineering of the structure of the solar cell at the micro and nanoscale, plasmonic structures, and more.
5. Cognitive ability experiment with photosensitive organic molecular thin films
CERN Document Server
Barille, R; Ortyl, E; Kucharski, S; Nunzi, J M; Barille, Regis; Ahmadi-Kandjani, Sohrab; Ortyl, Ewelina; Kucharski, Stanislaw; Nunzi, Jean-Michel
2006-01-01
We present an optical experiment which permits to evaluate the information exchange necessary to self-induce cooperatively a well-organized pattern in a randomly activated molecular assembly. A low-power coherent beam carrying polarization and wavelength information is used to organize a surface relief grating on a photochromic polymer thin film which is photo-activated by a powerful incoherent beam. We demonstrate experimentally that less than 1% of the molecules possessing information cooperatively transmit it to the entire photo-activated polymer film.
6. Morphology of polymer-based films for organic photovoltaics
OpenAIRE
Ruderer, Matthias A.
2012-01-01
In this thesis, polymer-based films are examined for applications in organic photovoltaics. Polymer-fullerene, polymer-polymer and diblock copolymer systems are characterized as active layer materials. The focus is on experimental parameters influencing the morphology formation of the active layer in organic solar cells. Scattering and imaging techniques provide a complete understanding of the internal structure on different length scales which is compared to spectroscopic and photovoltaic pr...
7. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films
Science.gov (United States)
David, Carey E.
1996-01-01
Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.
8. Study of neural cells on organic semiconductor ultra thin films
Energy Technology Data Exchange (ETDEWEB)
Bystrenova, Eva; Tonazzini, Ilaria; Stoliar, Pablo; Greco, Pierpaolo; Lazar, Adina; Dutta, Soumya; Dionigi, Chiara; Cacace, Marcello; Biscarini, Fabio [ISMN-CNR, Bologna (Italy); Jelitai, Marta; Madarasz, Emilia [IEM- HAS, Budapest (Hungary); Huth, Martin; Nickel, Bert [LMU, Munich (Germany); Martini, Claudia [Dept. PNPB, Univ. of Pisa (Italy)
2008-07-01
Many technological advances are currently being developed for nano-fabrication, offering the ability to create and control patterns of soft materials. We report the deposition of cells on organic semiconductor ultra-thin films. This is a first step towards the development of active bio/non bio systems for electrical transduction. Thin films of pentacene, whose thickness was systematically varied, were grown by high vacuum sublimation. We report adhesion, growth, and differentiation of human astroglial cells and mouse neural stem cells on an organic semiconductor. Viability of astroglial cells in time was measured as a function of the roughness and the characteristic morphology of ultra thin organic film, as well as the features of the patterned molecules. Optical fluorescence microscope coupled to atomic force microscope was used to monitor the presence, density and shape of deposited cells. Neural stem cells remain viable, differentiate by retinoic acid and form dense neuronal networks. We have shown the possibility to integrate living neural cells on organic semiconductor thin films.
9. Metal-organic frameworks: A thin film opening
Science.gov (United States)
Sumby, Christopher J.
2016-04-01
The properties of metal-organic frameworks -- promising for a myriad of applications -- can be commonly tuned by judicious choice of the building blocks used to prepare the material. Now, simply downsizing a rigid, non-porous MOF to a thin film has been shown to endow it with dynamic, gate-opening-type guest uptake behaviour.
10. Fundamentals of laser-assisted fabrication of inorganic and organic films
DEFF Research Database (Denmark)
Schou, Jørgen
The standard method for producing films by laser-assisted methods, Pulsed Laser Deposition (PLD) will be reviewed. The films considered are usually inorganic films, but also films of organic materials have been produced. Also the deposition of organic films by MAPLE (Matrix Assisted Pulsed Laser...... Evaporation), in which the target is replaced by a frozen matrix containing a few per cent film material, will be reviewed....
11. Theoretical and experimental studies of the recovery of volatile organic compounds from waste air streams in the thermal swing adsorption system with closed-loop regeneration of adsorbent
International Nuclear Information System (INIS)
Highlights: • The TSA process for VOCs recovery from the waste air was studied. • The closed-loop adsorbent regeneration method was used. • A mathematical model was developed to simulate the TSA process. • The toluene–Sorbonorit 4 activated carbon system was studied. • We proved that toluene can be recovered in moderate condensation temperature range. - Abstract: The cyclic thermal swing adsorption (TSA) process for volatile organic compounds (VOCs) recovery from the waste air is studied theoretically and experimentally. Toluene is chosen as the volatile organic compound. Activated carbon Sorbonorit 4 is used as an adsorbent. The TSA cycle is operated in three steps: an adsorption step with cold feed, a desorption step with hot purge gas and a cooling step with cold inert gas. The desorption and cooling are affected by nitrogen circulated through a heater, an adsorber and a condenser. A nonequilibrium, nonisothermal mathematical model is developed to simulate temperature and concentration breakthrough curves for both adsorption and desorption steps. The computer simulation results are compared with the experimental data. A bench scale fixed bed adsorption unit was used for the experimental study. It is shown that the theoretical model predicts the experimental results well. The computer simulation results are used to study the effect of the purge gas and condensation temperature on the process efficiency
12. Change in surface states of Ag(111) thin films upon adsorption of a monolayer of PTCDA organic molecules
International Nuclear Information System (INIS)
The change in the electronic structure of silver thin films of different thicknesses with the Ag( 111) orientation due to the interaction with an adsorbed monolayer of ordered organic molecules of 3,4,9,10-perylene-tetracarboxylic acid dianhydride (PTCDA) has been investigated in terms of density functional theory. It has been shown that one of the two surface states of the pure films transforms into an unocc upied interface state due to the interaction so that all the main features of the initial state are retained. The relation of the resulting state to the unoccupied state experimentally observed in the PTCDA/Ag( 111 ) system by scanning tunneling and two-photon photoemission spectroscopy has been discussed.
13. Self-organized structures in soft confined thin films
Indian Academy of Sciences (India)
Ashutosh Sharma
2005-10-01
We present a mini-review of our recent work on spontaneous, self-organized creation of mesostructures in soft materials like thin films of polymeric liquids and elastic solids. These very small scale, highly confined systems are inherently unstable and thus self-organize into ordered structures which can be exploited for MEMS, sensors, opto-electronic devices and a host of other nanotechnology applications. In particular, mesomechanics requires incorporation of intermolecular interactions and surface tension forces, which are usually inconsequential in classical macroscale mechanics. We point to some experiments and quasi-continuum simulations of self-organized structures in thin soft films which are germane not only to nanotechnology, but also to a spectrum of classical issues such as adhesion/debonding, wetting, coatings, tribology and membranes.
14. Fabrication of a room-temperature NO2 gas sensor based on WO3 films and WO3/MWCNT nanocomposite films by combining polyol process with metal organic decomposition method
International Nuclear Information System (INIS)
Research highlights: → In this study, we fabricated a room-temperature NO2 gas sensor based on WO3/MWCNT nanocomposite film by combining polyol process with metal organic decomposition method. → The response of the WO3/MWCNT nanocomposite film to NO2 gas increased dramatically when a few MWCNTs were added to the WO3 film. → New electrical paths and depletion layers formed in the WO3/MWCNT nanocomposite film were used to explain the high sensitivity of WO3/MWCNT nanocomposite film. - Abstract: Polyol process was combined with metal organic decomposition (MOD) method to fabricate a room-temperature NO2 gas sensor based on a tungsten oxide (WO3) film and another a nanocomposite film of WO3/multi-walled carbon nanotubes (WO3/MWCNTs). X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the structure and morphology of the fabricated films. Comparative gas sensing results indicated that the sensor that was based on the WO3/MWCNT nanocomposite film exhibited a much higher sensitivity than that based on a WO3 film in detecting NO2 gas at room temperature. Microstructural observations revealed that MWCNTs were embedded in the WO3 matrix. Therefore, a model of potential barriers to electronic conduction in the composite material was used to suggest that the high sensitivity is associated with the stretching of the two depletion layers at the surface of the WO3 film and at the interface of the WO3 film and the MWCNTs when detected gases are adsorbed at room temperature. The sensor that is based on a nanocomposite film of WO3/MWCNT exhibited a strong response in detecting very low concentrations of NO2 gas at room temperature and is practical because of the ease of its fabrication.
15. Exploration of exciton delocalization in organic crystalline thin films
Science.gov (United States)
Hua, Kim; Manning, Lane; Rawat, Naveen; Ainsworth, Victoria; Furis, Madalina
The electronic properties of organic semiconductors play a crucial role in designing new materials for specific applications. Our group recently found evidence for a rotation of molecular planes in phthalocyanines that is responsible for the disappearance of a delocalized exciton in these systems for T >150K.................()().......1 In this study, we attempt to tune the exciton delocalization of small organic molecules using strain effects and alloying different molecules in the same family. The exciton behavior is monitored using time- and polarization resolved photolumniscence (PL) spectroscopy as a function of temperature. Specifically, organic crystalline thin films of octabutoxy phthalocyanine (H2OBPc), octyloxy phthalocyanines and H-bonded semiconductors such as the quinacridone and indigo derivatives are deposited on flexible substrates (i.e. Kapton and PEN) using an in-house developed pen-writing method.........2 that results in crystalline films with macroscopic long range order. The room temperature PL studies show redshift and changes in polarization upon bending of the film. Crystalline thin films of alloyed H2OBPc and octabutoxy naphthalocyanine with ratios ranging from 1:1 to 100:1 fabricated on both sapphire and flexible substrates are also explored using the same PL spectroscopy to elucidate the behaviors of delocalized excitons. .1N. Rawat, et al., J Phys Chem Lett 6, 1834 (2015). 2R. L. Headrick, et al., Applied Physics Letters 92, 063302 (2008). NSF DMR-1056589, NSF DMR-1062966.
16. Thin films by metal-organic precursor plasma spray
Energy Technology Data Exchange (ETDEWEB)
Schulz, Douglas L.; Sailer, Robert A.; Payne, Scott; Leach, James; Molz, Ronald J. [North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Sulzer Metco (United States) Inc., Westbury, New York 11590-2724 (United States)
2009-07-15
While most plasma spray routes to coatings utilize solids as the precursor feedstock, metal-organic precursor plasma spray (MOPPS) is an area that the authors have investigated recently as a novel route to thin film materials. Very thin films are possible via MOPPS and the technology offers the possibility of forming graded structures by metering the liquid feed. The current work employs metal-organic compounds that are liquids at standard temperature-pressure conditions. In addition, these complexes contain chemical functionality that allows straightforward thermolytic transformation to targeted phases of interest. Toward that end, aluminum 3,5-heptanedionate (Al(hd){sub 3}), triethylsilane (HSi(C{sub 2}H{sub 5}){sub 3} or HSiEt{sub 3}), and titanium tetrakisdiethylamide (Ti(N(C{sub 2}H{sub 5}){sub 2}){sub 4} or Ti(NEt{sub 2}){sub 4}) were employed as precursors to aluminum oxide, silicon carbide, and titanium nitride, respectively. In all instances, the liquids contain metal-heteroatom bonds envisioned to provide atomic concentrations of the appropriate reagents at the film growth surface, thus promoting phase formation (e.g., Si-C bond in triethylsilane, Ti-N bond in titanium amide, etc.). Films were deposited using a Sulzer Metco TriplexPro-200 plasma spray system under various experimental conditions using design of experiment principles. Film compositions were analyzed by glazing incidence x-ray diffraction and elemental determination by x-ray spectroscopy. MOPPS films from HSiEt{sub 3} showed the formation of SiC phase but Al(hd){sub 3}-derived films were amorphous. The Ti(NEt{sub 2}){sub 4} precursor gave MOPPS films that appear to consist of nanosized splats of TiOCN with spheres of TiO{sub 2} anatase. While all films in this study suffered from poor adhesion, it is anticipated that the use of heated substrates will aid in the formation of dense, adherent films.
17. Reference spectra of important adsorbed organic and inorganic phosphate binding forms for soil P speciation using synchrotron-based K-edge XANES spectroscopy.
Science.gov (United States)
Prietzel, Jörg; Harrington, Gertraud; Häusler, Werner; Heister, Katja; Werner, Florian; Klysubun, Wantana
2016-03-01
Direct speciation of soil phosphorus (P) by linear combination fitting (LCF) of P K-edge XANES spectra requires a standard set of spectra representing all major P species supposed to be present in the investigated soil. Here, available spectra of free- and cation-bound inositol hexakisphosphate (IHP), representing organic P, and of Fe, Al and Ca phosphate minerals are supplemented with spectra of adsorbed P binding forms. First, various soil constituents assumed to be potentially relevant for P sorption were compared with respect to their retention efficiency for orthophosphate and IHP at P levels typical for soils. Then, P K-edge XANES spectra for orthophosphate and IHP retained by the most relevant constituents were acquired. The spectra were compared with each other as well as with spectra of Ca, Al or Fe orthophosphate and IHP precipitates. Orthophosphate and IHP were retained particularly efficiently by ferrihydrite, boehmite, Al-saturated montmorillonite and Al-saturated soil organic matter (SOM), but far less efficiently by hematite, Ca-saturated montmorillonite and Ca-saturated SOM. P retention by dolomite was negligible. Calcite retained a large portion of the applied IHP, but no orthophosphate. The respective P K-edge XANES spectra of orthophosphate and IHP adsorbed to ferrihydrite, boehmite, Al-saturated montmorillonite and Al-saturated SOM differ from each other. They also are different from the spectra of amorphous FePO4, amorphous or crystalline AlPO4, Ca phosphates and free IHP. Inclusion of reference spectra of orthophosphate as well as IHP adsorbed to P-retaining soil minerals in addition to spectra of free or cation-bound IHP, AlPO4, FePO4 and Ca phosphate minerals in linear combination fitting exercises results in improved fit quality and a more realistic soil P speciation. A standard set of P K-edge XANES spectra of the most relevant adsorbed P binding forms in soils is presented. PMID:26917141
18. Direct observation of epitaxial organic film growth: temperature-dependent growth mechanisms and metastability.
Science.gov (United States)
Marchetto, Helder; Schmidt, Thomas; Groh, Ullrich; Maier, Florian C; Lévesque, Pierre L; Fink, Rainer H; Freund, Hans-Joachim; Umbach, Eberhard
2015-11-21
The growth of the first ten layers of organic thin films on a smooth metallic substrate has been investigated in real-time using the model system PTCDA on Ag(111). The complex behaviour is comprehensively studied by electron microscopy, spectroscopy and diffraction in a combined PEEM/LEEM instrument revealing several new phenomena and yielding a consistent picture of this layer growth. PTCDA grows above room temperature in a Stranski-Krastanov mode, forming three-dimensional islands on a stable bi-layer, in competition with metastable 3rd and 4th layers. Around room temperature this growth mode changes into a quasi layer-by-layer growth, while at temperatures below about 250 K a Vollmer-Weber-like behaviour is observed. By means of laterally resolved soft X-ray absorption spectroscopy the orientation of all adsorbed molecules is found to be homogeneously flat lying on the surface, even during the growth process. The films grow epitaxially, showing long-range order with rotational domains. For the monolayer these domains could be directly analysed, showing an average size of several micrometers extending over substrate steps. PMID:26462749
19. Crystalline-to-plastic phase transitions in molecularly thin n-dotriacontane films adsorbed on solid surfaces
DEFF Research Database (Denmark)
Cisternas, Edgardo; Corrales, T. P.; del Campo, V.;
2009-01-01
identify with a solid-solid phase transition. At higher coverages, we observed additional steps in the ellipsometric signal that we identify with a solid-solid phase transition in multilayer islands (similar to 333 K) and with the transition to the rotator phase in bulk crystallites (similar to 337 K......), respectively. After considering three alternative explanations, we propose that the step upward in the ellipsometric signal observed at similar to 331 K on heating the submonolayer film is the signature of a transition from a perpendicular monolayer phase to a denser phase in which the alkane chains contain on...
20. Controlling Listeria monocytogenes on Pork Meat with Combinations of Lyophilized Cell-adsorbed Bacteriocin of Lactobacillus curvatus CWBI-B28 and Organic Acids or Salts
Directory of Open Access Journals (Sweden)
Privat Kouakou
2016-06-01
Full Text Available The main aim of this study was to see if the antilisterial action of lyophilized cell-adsorbed bacteriocin from Lactobacillus curvatus CWBI-B28 might be reinforced by simultaneous treatment with an organic acid or salt. Slices of raw pork (lean bacon inoculated with Listeria monocytogenes (at 102 cfu/g meat were either vacuum packaged directly and stored at 4°C or treated prior to packaging with a solution containing either lyophilized cell-adsorbed bacteriocin from Lactobacillus curvatus CWBI-B28 (at 1 g/100 mL, an organic acid or salt, or both. The organic acids/salts used were acetic acid, lactic acid, sodium acetate, sodium diacetate, potassium sorbate, and potassium benzoate and the concentrations of the corresponding solutions were calculated so as to treat each slice with approximately 0.1, 0.3, or 0.5 mg acid/salt. Of the antimicrobials used alone, LCaB had the strongest inhibitory effect (a 1-Log reduction in the Listeria cfu count after two weeks, followed by an increase. In combination with LCaB, three antimicrobials had a much more drastic effect: acetic acid, sodium diacetate, and potassium benzoate. At the highest acid/salt concentration tested in such combinations, Listeria became undetectable after one or two weeks and remained so until the end of the 6-week experiment.
1. Organic Dielectrics Influence the Crystallographic Structure of Pentacene Thin Films
International Nuclear Information System (INIS)
Full text: X-ray diffraction as well as atomic force microscopy experiments have been performed to investigate thin films of pentacene. The films were deposited on thermally grown SiO2 pre-covered by different organic layers. Modifying substrates that the substrate pre-treatments have a strong impact on the performance of the device as well as on the growth of the active layer. However, there are few reports about the influence on the crystalline properties of pentacene. In this work three different systems have been investigated. For one sample series vacuum deposited polymeric Parylene C - with varying thicknesses - was used as the dielectric layer. A second series of dielectric layers was prepared by spin coating a photoreactive polymer (PBHND [poly(bicyclo[2.2.1]hept-5-ene-2,3-(2- nitrobenzyl)dicarboxylate)]) onto the wafer. Subsequently the samples were exposed to UV-light for different time spans. For the third class of systems, a self assembled film of T-SC/SA [4-(2-(trichlorosilyl)ethyl)benzene-1-sulfonyl chloride (TSC), 30% sulfonic acid T-SA] was used to modify the SiOx surface. From the obtained x-ray data we find that the investigated pentacene films are polymorphic and consist of the two commonly observed crystal phases, namely the thin film phase and the Campbell phase. On weakly interacting substrates, these phases are typically oriented with their (001) lattice planes parallel to the substrate surface. Yet in the present investigation it is found that for some dielectric layers the (001) planes of the thin film phase are tilted approximately 3o and of the Campbell phase about 10o with respect to the substrate surface. These small deviations in the structure have a large influence to the in-plane diffraction patterns. Therefore, the changes in the patterns can be unambiguously attributed to the change of preferred orientation. (author)
2. Printed organic thin-film transistor-based integrated circuits
International Nuclear Information System (INIS)
Organic electronics is moving ahead on its journey towards reality. However, this technology will only be possible when it is able to meet specific criteria including flexibility, transparency, disposability and low cost. Printing is one of the conventional techniques to deposit thin films from solution-based ink. It is used worldwide for visual modes of information, and it is now poised to enter into the manufacturing processes of various consumer electronics. The continuous progress made in the field of functional organic semiconductors has achieved high solubility in common solvents as well as high charge carrier mobility, which offers ample opportunity for organic-based printed integrated circuits. In this paper, we present a comprehensive review of all-printed organic thin-film transistor-based integrated circuits, mainly ring oscillators. First, the necessity of all-printed organic integrated circuits is discussed; we consider how the gap between printed electronics and real applications can be bridged. Next, various materials for printed organic integrated circuits are discussed. The features of these circuits and their suitability for electronics using different printing and coating techniques follow. Interconnection technology is equally important to make this product industrially viable; much attention in this review is placed here. For high-frequency operation, channel length should be sufficiently small; this could be achievable with a combination of surface treatment-assisted printing or laser writing. Registration is also an important issue related to printing; the printed gate should be perfectly aligned with the source and drain to minimize parasitic capacitances. All-printed organic inverters and ring oscillators are discussed here, along with their importance. Finally, future applications of all-printed organic integrated circuits are highlighted. (paper)
3. Film stresses and electrode buckling in organic solar cells
KAUST Repository
Brand, Vitali
2012-08-01
We investigate the film stresses that develop in the polymer films and metal electrodes of poly(3-hexyl thiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) organic solar cells. A compressive biaxial stress of ∼-36 MPa was measured in PEDOT:PSS while a tensile stress of ∼6 MPa was measured in the BHJ layer. We then analyze the effect of electrode deposition rate on the film stresses in the Al electrode. Compressive stresses of ∼-100 to -145 MPa in the Al electrode lead to a buckling instability resulting in undulating electrode surface topography. The BHJ layer was found to have the lowest cohesion (∼1.5-1.8 J/m 2) among the layers of the solar cell and dependent on the Al electrode deposition rate. The cohesive failure path in the BHJ layer exhibited the same periodicity and orientation of the Al electrode buckling topography. We discuss the implications of the film stresses on damage processes during device fabrication and operation. © 2012 Elsevier B.V. All rights reserved.
4. Adsorption energy and geometry of adsorbed organic molecules on Au(111) probed by surface-state photoemission
Energy Technology Data Exchange (ETDEWEB)
Ziroff, Johannes; Forster, Frank [Universitaet Wuerzburg, Experimentelle Physik II, D-97074 Wuerzburg (Germany); Reinert, Friedrich [Universitaet Wuerzburg, Experimentelle Physik II, D-97074 Wuerzburg (Germany); Forschungszentrum Karlsruhe, Gemeinschaftslabor fuer Nanoanalytik, D-76021 Karlsruhe (Germany)
2009-07-01
The modification of the Au(111) surface states by an adsorbed monolayer of large {pi}-conjugated molecules (PTCDA, NTCDA, CuPc) was investigated by high-resolution angle-resolved photoelectron spectroscopy. We determined binding energy, band mass, and Rashba-splitting and discuss the results in the context of rare-gas adsorption on noble metals. This comparison allows the determination of the bonding strength of the adsorbates, found to be physisorptive with derived binding energies per molecule of 2.0 eV for PTCDA and 1.5 eV for NTCDA. We will also present a superstructure model for the NTCDA/Au(111) system, deduced from low energy electron diffraction images in combination with band-backfolding of the Tamm and Shockley states. The coverage dependent evolution of the surface states was also investigated for the three molecules, giving evidence for a dilute-phase growth of the CuPc molecule on the Au(111) surface.
5. Development of adsorbents from used tire rubber. Their use in the adsorption of organic and inorganic solutes in aqueous solution
Energy Technology Data Exchange (ETDEWEB)
Troca-Torrado, Cesar; Alexandre-Franco, Maria; Fernandez-Gonzalez, Carmen; Gomez-Serrano, Vicente [Extremadura Univ., Badajoz (Spain). Dept. de Quimica Organica e Inorganica; Alfaro-Dominguez, Manuel [Extremadura Univ., Badajoz (Spain). Dept. de Ingenieria Mecanica, Energetica y de los Materiales
2011-02-15
Using used tire rubber (UTR), carbonaceous adsorbents (CAs) were prepared by chemical treatment of the material with HCl, HNO{sub 3} and NaOH aqueous solutions and by heat treatment at 900 C for 2 h in N{sub 2} atmosphere (H900). UTR and the UTR-derived products were first characterized in terms of texture by N{sub 2} adsorption at - 196 C and of oxygen surface groups by FT-IR spectroscopy and pH of the point of zero charge (pH{sub pzc}). Then, the products were tested as adsorbents of phenol, p-aminophenol, p-nitrophenol, and p-chlorophenol and of chromium, cadmium, mercury and lead in aqueous solution. The development of porosity is very poor in UTR and in the chemically treated products. H900 is the only CA with a better developed porosity, mainly in the regions of meso and macropores. pH{sub pzc} is close to 7.0 for most of the CAs. As an exception to the rule, pH{sub pzc} is 8.4 for H900. For this CA, the adsorption of all the adsorptives is greater. Usually, adsorption kinetics are fast. This is so in particular for p-nitrophenol and p-chlorophenol, on the one side, and for mercury and lead, on the other side. Adsorption is much higher for mercury and lead than for the remaining adsorptives. (author)
6. Graphene nanosheets as novel adsorbents in adsorption, preconcentration and removal of gases, organic compounds and metal ions
International Nuclear Information System (INIS)
Due to their high adsorption capacities, carbon-based nanomaterials such as carbon nanotubes, activated carbons, fullerene and graphene are widely used as the currently most promising functional materials. Since its discovery in 2004, graphene has exhibited great potential in many technological fields, such as energy storage materials, supercapacitors, resonators, quantum dots, solar cells, electronics, and sensors. The large theoretical specific surface area of graphene nanosheets (2630 m2·g−1) makes them excellent candidates for adsorption technologies. Further, graphene nanosheets could be used as substrates for decorating the surfaces of nanoparticles, and the corresponding nanocomposites could be applied as novel adsorbents for the removal of low concentrated contaminants from aqueous solutions. Therefore, graphene nanosheets will challenge the current existing adsorbents, including other types of carbon-based nanomaterials. - Highlights: • The recent progress of application of graphene in adsorption was presented. • The design and practical application of graphene based composites was discussed. • The future trends and prospects of graphene were analyzed and proposed
7. Cellulose nanocrystals as organic nanofillers for transparent polycarbonate films
International Nuclear Information System (INIS)
Cellulose nanocrystals (CNCs) produced by sulfuric acid hydrolysis as organic nanofillers were dispersed into polycarbonate (PC) in organic solution through a solvent exchange procedure, and their influence on the optical, mechanical, and thermal properties of the resulting composite films were studied. It is demonstrated that due to the good dispersion of the nanofillers in the polymeric matrix, the formation of strong hydrogen bonds between carbonyl groups of PC and hydroxyl groups of the CNCs can be achieved, leading to a simultaneous reinforcement effect on mechanical and thermal properties of the composite films. Moreover, it was further found that the existence of nanofillers in the composite efficiently hindered the main thermal degradation pathways of PC involving the chain scission at carbonate linkage and rearrangement of carbonate groups. Compared with neat PC, the composite film with 3 wt% CNCs has an increase of about 30.6 % in tensile strength, 27.3 % in Young’s modulus, and 3.3 % in maximum decomposition temperature, but still remain quite transparent.
8. Multifunctional organic thin films and their electronic/optical properties
Science.gov (United States)
Shao, Yan
The concept of multifunctional organic thin films and their electronic/optical properties has been applied to organic functional device design, fabrication, and characterization. The organic devices involve organic light-emitting diodes (OLEDs) and organic photovoltaic devices (OPV) in this dissertation. In the research of graded junction structure of OLEDs, two kinds of naturally-formed graded junction (NFGJ) structures, sharp and shallow graded junctions, can be formed using single thermal evaporation boat loaded with uniformly mixed charge transport and light-emitting materials. OLEDs with NFGJ have been demonstrated in Chapter 3; the performance is comparable to the heterojunction OLEDs, but with better device lifetime. A novel method to prepare highly uniform mixed organic solid solutions through a high temperature and high-pressure fusion process has been demonstrated in Chapter 4. A series of fused organic solid solution (FOSS) compounds with NPD doped with different organic emitting dopants were prepared and DSC technique was utilized to determine the thermal characteristics. For the first time, the schematic phase diagram for this binary system has been obtained. High performance OLEDs of single color and white emission were fabricated and the device properties were characterized. In Chapter 5, an efficient photovoltaic heterojunction of tetracene and fullerene has been investigated and high performance organic solar cells have been demonstrated by thermal deposition and successive heat treatment. The preliminary conclusion for this enhancement is discussed and supported by atomic force microscopy images, absorption spectra and x-ray diffraction analysis. Additionally, an effective organic photovoltaic heterojunction based on the typical triplet material PtOEP was demonstrated. It is believed that introducing appropriate organic materials with long exciton lifetime is a very promising way to improve photovoltaic performance.
9. Two-Dimensional Organic-Inorganic Hybrid Perovskite Photonic Films.
Science.gov (United States)
Meng, Ke; Gao, Shanshan; Wu, Longlong; Wang, Geng; Liu, Xin; Chen, Gang; Liu, Zhou; Chen, Gang
2016-07-13
Organic-inorganic hybrid perovskites have created enormous expectations for low-cost and high-performance optoelectronic devices. In prospect, future advancements may derive from reaping novel electrical and optical properties beyond pristine perovskites through microscopic structure design and engineering. Herein, we report the successful preparation of two-dimensional inverse-opal perovskite (IOP) photonic films, featuring unique nanostructures and vivid colors. Further compositional and structural managements promise optical property and energy level tunability of the IOP films. They are further functionalized in solar cells, resulting in colorful devices with respectable power conversion efficiency. Such concept has not been previously applied for perovskite-based solar cells, which could open a route for more versatile optoelectronic devices. PMID:27267266
10. Orbital tomography for highly symmetric adsorbate systems
Science.gov (United States)
Stadtmüller, B.; Willenbockel, M.; Reinisch, E. M.; Ules, T.; Bocquet, F. C.; Soubatch, S.; Puschnig, P.; Koller, G.; Ramsey, M. G.; Tautz, F. S.; Kumpf, C.
2012-10-01
Orbital tomography is a new and very powerful tool to analyze the angular distribution of a photoemission spectroscopy experiment. It was successfully used for organic adsorbate systems to identify (and consequently deconvolute) the contributions of specific molecular orbitals to the photoemission data. The technique was so far limited to surfaces with low symmetry like fcc(110) oriented surfaces, owing to the small number of rotational domains that occur on such surfaces. In this letter we overcome this limitation and present an orbital tomography study of a 3,4,9,10-perylene-tetra-carboxylic-dianhydride (PTCDA) monolayer film adsorbed on Ag(111). Although this system exhibits twelve differently oriented molecules, the angular resolved photoemission data still allow a meaningful analysis of the different local density of states and reveal different electronic structures for symmetrically inequivalent molecules. We also discuss the precision of the orbital tomography technique in terms of counting statistics and linear regression fitting algorithm. Our results demonstrate that orbital tomography is not limited to low-symmetry surfaces, a finding which makes a broad field of complex adsorbate systems accessible to this powerful technique.
11. A rapid microwave-assisted synthesis of a sodium-cadmium metal-organic framework having improved performance as a CO2 adsorbent for CCS.
Science.gov (United States)
Palomino Cabello, Carlos; Arean, Carlos Otero; Parra, José B; Ania, Conchi O; Rumori, P; Turnes Palomino, G
2015-06-01
We report on a facile and rapid microwave-assisted method for preparing a sodium-cadmium metal-organic framework (having coordinatively unsaturated sodium ions) that considerably shortens the conventional synthesis time from 5 days to 1 hour. The obtained (Na,Cd)-MOF showed an excellent volumetric CO2 adsorption capacity (5.2 mmol cm(-3) at 298 K and 1 bar) and better CO2 adsorption properties than those shown by the same metal-organic framework when synthesized following a more conventional procedure. Moreover, the newly prepared material was found to display high selectivity for adsorption of carbon dioxide over nitrogen, and good regenerability and stability during repeated CO2 adsorption-desorption cycles, which are the required properties for any adsorbent intended for carbon dioxide capture and sequestration (CSS) from the post-combustion flue gas of fossil fuelled power stations. PMID:25939594
12. Thin Film Solar Cells: Organic, Inorganic and Hybrid
Science.gov (United States)
Dankovich, John
2004-01-01
Thin film solar cells are an important developing resource for hundreds of applications including space travel. In addition to being more cost effective than traditional single crystal silicon cells, thin film multi-crystaline cells are plastic and light weight. The plasticity of the cells allows for whole solar panels to be rolled out from reams. Organic layers are being investigated in order to increase the efficiency of the cells to create an organic / inorganic hybrid cell. The main focus of the group is a thin film inorganic cell made with the absorber CuInS2. So far the group has been successful in creating the layer from a single-source precursor. They also use a unique method of film deposition called chemical vapor deposition for this. The general makeup of the cell is a molybdenum back contact with the CuInS2 layer, then CdS, ZnO and aluminum top contacts. While working cells have been produced, the efficiency so far has been low. Along with quantum dot fabrication the side project of this that is currently being studied is adding a polymer layer to increase efficiency. The polymer that we are using is P3OT (Poly(3-octylthiopene-2,5-diyll), retroregular). Before (and if) it is added to the cell, it must be understood in itself. To do this simple diodes are being constructed to begin to look at its behavior. The P3OT is spin coated onto indium tin oxide and silver or aluminum contacts are added. This method is being studied in order to find the optimal thickness of the layer as well as other important considerations that may later affect the composition of the finished solar cell. Because the sun is the most abundant renewable, energy source that we have, it is important to learn how to harness that energy and begin to move away from our other depleted non-renewable energy sources. While traditional silicon cells currently create electricity at relatively high efficiencies, they have drawbacks such as weight and rigidness that make them unattractive
13. Controlled Growth of Ultrathin Film of Organic Semiconductors by Balancing the Competitive Processes in Dip-Coating for Organic Transistors.
Science.gov (United States)
Wu, Kunjie; Li, Hongwei; Li, Liqiang; Zhang, Suna; Chen, Xiaosong; Xu, Zeyang; Zhang, Xi; Hu, Wenping; Chi, Lifeng; Gao, Xike; Meng, Yancheng
2016-06-28
Ultrathin film with thickness below 15 nm of organic semiconductors provides excellent platform for some fundamental research and practical applications in the field of organic electronics. However, it is quite challenging to develop a general principle for the growth of uniform and continuous ultrathin film over large area. Dip-coating is a useful technique to prepare diverse structures of organic semiconductors, but the assembly of organic semiconductors in dip-coating is quite complicated, and there are no reports about the core rules for the growth of ultrathin film via dip-coating until now. In this work, we develop a general strategy for the growth of ultrathin film of organic semiconductor via dip-coating, which provides a relatively facile model to analyze the growth behavior. The balance between the three direct factors (nucleation rate, assembly rate, and recession rate) is the key to determine the growth of ultrathin film. Under the direction of this rule, ultrathin films of four organic semiconductors are obtained. The field-effect transistors constructed on the ultrathin film show good field-effect property. This work provides a general principle and systematic guideline to prepare ultrathin film of organic semiconductors via dip-coating, which would be highly meaningful for organic electronics as well as for the assembly of other materials via solution processes. PMID:27267545
14. Quantification of LEED measurements. II. Application to epitaxial organic films
Energy Technology Data Exchange (ETDEWEB)
Meissner, Matthias; Sojka, Falko; Gruenewald, Marco; Forker, Roman; Fritz, Torsten [University of Jena, Institute of Solid State Physics, Max-Wien-Platz 1, 07743 Jena (Germany)
2012-07-01
Low energy electron diffraction (LEED) on epitaxial layers is a powerful tool to examine long-range ordering at the interface. However, due to limitations like distortion of the LEED images, often additional efforts have to be made in order to derive precise epitaxial relations. Based on LEED images corrected for their distortion and calibrated by means of a Si(111)-7 x 7 diffraction pattern, a home-made algorithm finds the LEED spots belonging to a certain structure and fits a lattice to all those spots simultaneously. This provides us with absolute lattice parameters within a small error margin. Additionally, in the case of organic-inorganic epitaxy, measurements at higher energies can be used to relate the adsorbate lattice to the substrate lattice and derive the epitaxy matrix. The precision of this procedure will be evaluated on the basis of two systems: (a) 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on epitaxial graphene, featuring two different PTCDA phases, one known, the other not; (b) Tin-phthalocyanine (SnPc) on Au(111), not being described in literature yet.
15. High performance small-molecule organic thin film transistors
Science.gov (United States)
Kuo, Chung-Chen
The roadmap of developing microelectronics has a new branch: organic electronics. Organic electronics, which utilizes the electrical properties of organic materials in the active or passive layers, is an emerging technology that has received much attention. In conjunction with today's demands for new materials and devices, many technologies have emerged for developing organic electronics and consolidating applications and markets. An organic thin-film transistor is the essential device in this paradigm in addition to organic photodiodes and organic light emitting diodes. This thesis presents advances made in design and fabrication of organic thin-film transistors (OTFTs) using small-molecule organic semiconductors (pentacene, anthradithiophene, and their derivatives) as the active layer with record device performance. In this work OTFT test structures fabricated on oxidized silicon substrates were utilized to provide a convenient substrate, gate contact, and gate insulator for the processing and characterization of vapor-deposited organic materials and their transistors. By developing a gate dielectric treatment using silane coupling agents the performance and yield of pentacene OTFTs was improved and a field-effect mobility of larger than 2 cm2/V-s was achieved. Such device performance is comparable to a-Si:H TFTs and have the potential for electronic applications. In addition, the first direct photolithographic process for top contacts to pentacene OTFTs on oxidized silicon with an acceptable performance (a field-effect mobility of 0.3 cm2/V-s, an on/off current ratio of 10 7, and a subthreshold slope of 1 V/decade) was developed. The multiple layer photoresist process demonstrated the feasibility of creating source and drain metallic electrodes on vapor-deposited pentacene thin films with a resolution less than 10 mum. Subsequently, solution-processed OTFTs were then investigated and high performance transistors, with field-effect mobilities > 1 cm2/V-s and an
16. Semiconducting Organic Thin Film Devices with Large Magnetoresistance
Science.gov (United States)
Sheng, Y.; Mermer, Ö.; Veeraraghavan, G.; Nguyen, T. D.; Francis, T. L.; Wohlgenannt, M.
2006-03-01
A comprehensive study on a recently discovered, large magnetoresistance (MR) effect in sandwich devices comprised of nonmagnetic electrodes and organic thin films is performed. Devices were fabricated from pi-conjugated polymers and small molecular weight compounds in combination with different electrode materials, and characterized extensively at different voltages, temperatures, and at weak magnetic fields from DC up to 100 kHz in frequency. The MR effect shows only weak temperature dependence and is independent of the sign and direction of the magnetic field. The effect reaches up to 10% in a magnetic field of 10 mT at room temperature. To illustrate a potential application of the effect, we demonstrate a prototype organic LED (OLED) touchscreen using the MR effect. To the best of our knowledge, the discovered effect is not adequately described by any of the MR mechanisms known to date.
17. Stabilization of organic thin film transistors by ion implantation
Energy Technology Data Exchange (ETDEWEB)
Fraboni, B., E-mail: [email protected] [CNISM and Dipartimento di Fisica, Universita di Bologna, viale Berti Pichat 6/2, 40127 Bologna (Italy); Cosseddu, P. [Dipartimento di Ingegneria Elettrica ed Elettronica, Universita di Cagliari, piazza d' Armi, 09123 Cagliari, Italy and CNR-INFM S3 via Campi 213/a 41100 Modena (Italy); Wang, Y.Q.; Schulze, R.K. [Los Alamos National Laboratory MS-K771 Los Alamos NM 87545 (United States); Cavallini, A. [CNISM and Dipartimento di Fisica, Universita di Bologna, viale Berti Pichat 6/2, 40127 Bologna (Italy); Nastasi, M. [Los Alamos National Laboratory MS-K771 Los Alamos NM 87545 (United States); Bonfiglio, A. [Dipartimento di Ingegneria Elettrica ed Elettronica, Universita di Cagliari, piazza d' Armi, 09123 Cagliari, Italy and CNR-INFM S3 via Campi 213/a 41100 Modena (Italy)
2012-08-01
We report on the effects of low energy ion implantation (N and Ne) in the reduction and control of the degradation of pentacene organic thin film transistors (OTFTs) due to the exposure to atmosphere (i.e. oxygen and water). We have observed that a controlled damage depth distribution preserves the functionality of the devices, even if ion implantation induces significant molecular structure modifications, in particular a combination of dehydrogenation and carbonification effects. No relevant changes in the pentacene thin film thickness have been observed. The two major transport parameters that characterize OTFT performance are the carrier mobility and the threshold voltage. We have monitored the effectiveness of this process in stabilizing the device by monitoring the carrier mobility and the threshold voltage over a long time (over 2000 h). Finally, we have assessed by depth resolved X-ray Photoemission Spectroscopy analyses that, by selectively implanting with ions that can react with the hydrocarbon matrix (e.g. N{sup +}), it is possible to locally modify the charge distribution within the organic layer.
18. Optical analysis of trap states in amorphous organic semiconductor films
Energy Technology Data Exchange (ETDEWEB)
Graaf, Harald; Borczyskowski, Christian von [Center of Nanostructured Materials and Analytics, Chemnitz University of Technology (Germany); Friedriszk, Frank [Center of Nanostructured Materials and Analytics, Chemnitz University of Technology (Germany); Institut fuer Physik, Universitaet Rostock (Germany)
2010-07-01
Increasing interest is drawn on thin organic semiconductor films in opto-electronic devices. While for applications like field-effect transistors and photovoltaic cells highly ordered morphologies resulting in higher charge carrier mobilities are requested, for other purposes like organic light emitting diodes amorphous arrangement of the molecules is needed. Here lower mobilities increase the recombination rate leading to a higher photon yield. In such systems trap states can influence dramatically the luminescence in its intensity and spectral regime. We show recent results on amorphous films of a perylene dye with a rather high concentration of trap states. These trap states act as sinks for the excitons and leads therefore to a clear shift of the luminescence to the red compared to the monomer emission. Temperature depended and time resolved measurements give a clear hint for the population of the traps from the exciton band. Comparisons with previous electrical measurements lead us to the assumption, that these traps are also dominating the charge carrier mobility within the material.
19. Dependence of interfacial film organization on lipid molecular structure.
Science.gov (United States)
Matyszewska, Dorota; Sek, Slawomir; Jabłonowska, Elżbieta; Pałys, Barbara; Pawlowski, Jan; Bilewicz, Renata; Konrad, Fabian; Osornio, Yazmin M; Landau, Ehud M
2014-09-30
Combination of surface analytical techniques was employed to investigate the interfacial behavior of the two designed lipids-N-stearoylglycine (1) and its bulky neutral headgroup-containing derivative N-stearoylvaline ethyl ester (2)-at the air-solution interface and as transferred layers on different substrates. Formation of monolayers at the air-water interface was monitored on pure water and on aqueous solutions of different pH. Crystallization effects were visualized at pure water by recording the hystereses in the Langmuir-Blodgett (LB) isotherms and by transferring the layers onto mica, gold (111), and ITO (indium-tin oxide on glass) electrodes. Subphase pH affects the morphology and patch formation in monolayers of 1, as evidenced by BAM measurements. At pH 8.2, formation of well-ordered crystallites is observed, which upon compression elongate according to predominantly 1-D growth mechanism to form a dense layer of crystallites. This effect is not observed in monolayers of 2, whose headgroup is not protonated. The orientation of layers of 1 transferred to the solid supports is also pH dependent, and their stability can be related to formation of a hydrogen-bonded networks. AFM images of 1 exhibited platelets of multilayer phase. The IR spectra of the ITO substrates covered by 1 indicated formation of hydrogen bonds between the amide groups. The nature of the adsorption layer and its organization as a function of potential were studied in-depth by EC STM using Au(111) as the substrate. A model showing the arrangement of hydrogen bonds between adsorbed molecules is presented and related to the observed organization of the layer. PMID:25229461
20. Nanoporous carbon derived from a metal organic framework as a new kind of adsorbent for dispersive solid phase extraction of benzoylurea insecticides
International Nuclear Information System (INIS)
We describe the preparation of nanoporous carbon using a metal-organic framework (MOF) as a template and furfuryl alcohol as the source for carbon. The MOF consists of a zeolitic framework (ZIF-8) that was obtained from 2-methylimidazole and Zn(II) ions. ZIF-8 was soaked with furfuryl alcohol which then was carbonized at 900 °C. The resulting nanoporous carbon (MOF-C) exhibits a high specific surface area and a large pore volume. It was used as a dispersive solid-phase adsorbent for the preconcentration of the benzoylurea insecticides diflubenzuron, triflumuron, hexaflumuron and teflubenzuron from water and tangerine samples. Under optimized conditions, the methods exhibits excellent extraction performance. The insecticides can be quantified via HPLC with UV detection in the 0.5 to 100 ng mL−1 concentration range in case of spiked tap water, and in the 2.0 to 200 ng g−1 concentration range in case of tangerines. The limits of detection range from 0.10 to 0.23 ng mL−1 in case of water samples, and from 0.34 to 0.71 ng g−1 for tangerine sample (at an S/N ratio of 3). Mean recoveries range from 91.7 to 107.9 %, with relative standard deviations of <7.1 %. The results indicate that the method was efficient for the preconcentration of trace levels of benzoylurea insecticides from water and tangerine samples. Conceivably, this new adsorbent has a large potential with respect to the enrichment of other organic pollutants from various kinds of samples. (author)
1. Bilayer Photoresist Insulator for High Performance Organic Thin-Film Transistors on Plastic Films
International Nuclear Information System (INIS)
A novel bilayer photoresist insulator is applied in flexible vanadyl-phthalocyanine (VOPc) organic thin-film transistors (OTFTs). The micron-size patterns of this photoresisit insulator can be directly defined only by photolithography without the etching process. Furthermore, these OTFTs exhibit high field-effect mobility (about 0.8 cm2/Vs) and current on/off ratio (about 106). In particular, they show rather low hysteresis (< 1 V). The results demonstrate that this bilayer photoresist insulator can be applied in large-area electronics and in the facilitation of patterning insulators. (cross-disciplinary physics and related areas of science and technology)
2. Organic and inorganic-organic thin film structures by molecular layer deposition: A review.
Science.gov (United States)
Sundberg, Pia; Karppinen, Maarit
2014-01-01
The possibility to deposit purely organic and hybrid inorganic-organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD), is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD) technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic-organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications. PMID:25161845
3. Organic and inorganic–organic thin film structures by molecular layer deposition: A review
Directory of Open Access Journals (Sweden)
Pia Sundberg
2014-07-01
Full Text Available The possibility to deposit purely organic and hybrid inorganic–organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD, is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic–organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications.
4. Influence of organic acids on kinetic release of chromium in soil contaminated with leather factory waste in the presence of some adsorbents.
Science.gov (United States)
Taghipour, Marzieh; Jalali, Mohsen
2016-07-01
In this study, batch experiments were conducted to investigate the effects of nanoparticles (NPs) (MgO, ZnO, TiO2) and clay minerals (bentonite, zeolite) on the release of chromium (Cr) from leather factory waste (LFW) and LFW treated soil using organic acids. Chromium release from all treatments was studied in the presence of citric acid, oxalic acid and CaCl2 solutions. The results showed that, in all treatments, organic acids released more Cr than inorganic salt (CaCl2). The release of Cr by citric acid was higher than that by oxalic acid. In LFW treated soil and LFW, the release of Cr from the all treatments with NPs was less than that from the clay mineral treatments. On the other hand, in the presence of organic acids, Cr release by NPs and clay minerals decreased. Two kinetic models including pseudo-first- and pseudo-second-order model were tested to describe the time dependent Cr release data. Among the kinetic models used, the pseudo-second-order model generally gave the best fits to experimental data. Before and after release experiments, Cr in LFW, treated LFW, control soil and LFW treated soils were fractionated. In all treatments, the greatest amounts of Cr were found in the residual fraction (RES). The organic acids were effective in reducing the exchangeable (EXC), bound to organic matter (OM) and bound to carbonate (CAR) fractions of Cr in all treatments, whereas, after release of Cr from treated soils, Cr remained mainly in the RES fraction. The application of NPs and clay minerals in soil led to a significant transformation of Cr from mobile fractions to the RES fraction. Therefore, organic ligands played a dominant role in mobility and bioavailability of Cr and the removal of Cr by adsorbents. PMID:27139119
5. QSAR models for removal rates of organic pollutants adsorbed by in situ formed manganese dioxide under acid condition.
Science.gov (United States)
Su, Pingru; Zhu, Huicen; Shen, Zhemin
2016-02-01
Manganese dioxide formed in oxidation process by potassium permanganate exhibits promising adsorptive capacity which can be utilized to remove organic pollutants in wastewater. However, the structure variances of organic molecules lead to wide difference of adsorption efficiency. Therefore, it is of great significance to find a general relationship between removal rate of organic compounds and their quantum parameters. This study focused on building up quantitative structure activity relationship (QSAR) models based on experimental removal rate (r(exp)) of 25 organic compounds and 17 quantum parameters of each organic compounds computed by Gaussian 09 and Material Studio 6.1. The recommended model is rpre = -0.502-7.742 f(+)x + 0.107 E HOMO + 0.959 q(H(+)) + 1.388 BOx. Both internal and external validations of the recommended model are satisfied, suggesting optimum stability and predictive ability. The definition of applicability domain and the Y-randomization test indicate all the prediction is reliable and no possibility of chance correlation. The recommended model contains four variables, which are closely related to adsorption mechanism. f(+)x reveals the degree of affinity for nucleophilic attack. E HOMO represents the difficulty of electron loss. q(H(+)) reflect the distribution of partial charge between carbon and hydrogen atom. BO x shows the stability of a molecule. PMID:26490942
6. Organic Thin Film Devices for Displays and Lighting
Science.gov (United States)
Weiss, Oliver J.; Krause, Ralf; Paetzold, Ralph
Organic materials can be used for fabrication of, e.g., electronic circuits, solar cells, light sensors, memory cells and light emitting diodes. Especially organic light emitting diodes (OLEDs) are increasingly attractive because of their huge market potential. The feasibility of efficient OLEDs was first shown in 1987 [3]. Only about ten years later the first product, a display for car radios, entered the market. Today monochrome and full colour OLED-displays can be found in many applications replacing established flat panel display technologies like TFT-LCDs. This substitution is a consequence of the outstanding attributes of OLED technology: Organic light emitting displays are self-emissive, thin, video capable and in addition they show a wide temperature operation range and allow a viewing angle of nearly 180 degree in conjunction with a low power consumption. As performance has steadily increased over the last years, today OLEDs are also under investigation as next generation light source. In contrast to inorganic LEDs, they can be built as flat 2-dimensional light sources that are lightweight, colour tunable, and potentially cheap. This will open up new degrees of freedom in design leading also to completely new applications. In this contribution we will have a brief view on the history of organic electroluminescent materials before we introduce the basic principles of OLEDs with a focus on the physical processes leading to light generation in thin organic films. Along with an overview of different concepts and technologies used to build OLEDs, the current status of OLED development will be illustrated. The last part focuses on the challenges that have to be overcome to enable a sustainable success in the display and lighting markets.
7. Preparation of organic thin-film field effect transistor
Institute of Scientific and Technical Information of China (English)
2002-01-01
The organic thin-film field effect transistor was prepared through vacuum deposition by using teflon as di-electric material. Indium-tin-oxide acted as the source and drain electrodes. Copper phthalocyanine and teflon were used as the semiconductor layer and dielectric layer, respectively. The gate electrode was made of Ag. The channel length between the source and drain was 50 μm. After preparing the source and drain electrodes by lithography, the copper phthalocyanine layer, teflon layer and Ag layerwere prepared by vacuum deposition sequentially. The field effect electron mobility of the device reached 1.1×10ˉ6 cm2/(V@s), and the on/off current ratio reached 500.
8. Organically Modified Nanoclay-Reinforced Rigid Polyurethane Films
Science.gov (United States)
Park, Yong Tae; Qian, Yuqiang; Lindsay, Chris; Stein, Andreas; Macosko, Christopher
2012-02-01
The nanodispersion of vermiculite in polyurethanes was investigated to produce organoclay-reinforced rigid gas barrier films. Reducing gas transport can improve the insulation performance of closed cell polyurethane foam. In a previous study, the dispersion of vermiculite in polyurethanes without organic modification was not sufficient due to the non-uniform dispersion morphology. When vermiculite was modified by cation exchange with long-chain quaternary ammonium cations, the dispersion in methylene diphenyl diisocyanate (MDI) was significantly improved. Dispersion was improved by combining high intensity dispersive mixing with efficient distributive mixing. Polymerization conditions were also optimized in order to provide a high state of nanodispersion in the polyurethane nanocomposite. The dispersions were characterized using rheological, microscopic and scattering/diffraction techniques. The final nanocomposites showed enhancement of mechanical properties and reduction in permeability to carbon dioxide at low clay concentration (around 2 wt percent).
9. Adsorbate-modified growth of ultrathin rare-earth oxide films on silicon and complementary studies of cerium oxide on ruthenium
International Nuclear Information System (INIS)
Rare-earth oxides (REOx) are extensively investigated due to their extraordinary physical and chemical properties, which essentially arise from the unfilled 4f electron shell, in order to reveal the nature of these exceptional properties and ultimately to utilize them for multiple technological applications. To maintain the exponential increase in integration density in CMOS technology, which is also known as Moore s law, there is a strong desire for ultrathin, well-ordered, epitaxial REOx layers with a precisely engineered interface, which is essential for reliable, ultrahigh-performance devices. So far this has been considerably impeded by RE-promoted silicon oxidation, leading to amorphous silicon oxide and RE silicon formation. By using complementary synchrotron radiation methods such as X-ray standing waves (XSW), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), structural and spectroscopic information are inferred simultaneously from ultrathin ceria and lanthana films grown on chlorine, silver and gallium passivated silicon(111). In general, it is revealed that the chemical and structural composition of the interface and the crystallinity of ultrathin REOx layers on silicon can be precisely controlled by adsorbate-mediated growth. This might represent a crucial step towards a perfectly engineered interface, eventually allowing for the integration of REOx as high-k gate oxides in microelectronics. In catalysis inverse model catalysts are studied with the aim of getting an in-depth understanding of the basic principles of catalysis. These model systems are employed to study, e. g., the nature of active sites and the reaction pathways in complex catalytic converters. However, a lot remains unknown about the chemical activity and selectivity as a function of the growth mechanism, structure and morphology of these model systems. The powerful spectroscopic photoemission and low-energy electron microscope, which is able to reveal the surface
10. Optical properties of organic films, multilayers and plasmonic metal-organic waveguides fabricated by organic molecular beam deposition
Science.gov (United States)
Wickremasinghe, Niranjala D.
In this thesis, the optical properties of tris (8-hydroxyquinoline) aluminum (Alq3) and 3,5,9,10-perylentetracarboxylic dianhydride (PTCDA) organic films, PTCDA/ Alq3 multilayers and plasmonic Alq3 -metal waveguides are investigated. The organic films and heterostructures used for this work were fabricated by organic molecular beam deposition (OMBD). We investigated the quenching of the light emission in Alq3 films grown on a Si substrate as a function of cw laser excitation intensity at varying temperatures from 15 to 300 K. The saturation of the singlet-singlet annihilation coefficient was measured with spectrally-integrated (SI) photoluminescence (PL) using a photodiode. The bimolecular quenching coefficient was further studied with time-resolved (TR) PL as a function of 100 fs pulse fluences. The PL quenching is attributed to the annihilation of trapped excitons at Alq3 nanocrystal grain boundaries. The saturation is explained by the limited density of available trapping states at the grain boundaries. Our interpretation is supported by structural investigations of ultrathin Alq3 films with atomic force microscopy (AFM), scanning electron microscopy (SEM) and by comparing the experimental data with calculations using a coupled rate equation model. The wavelength dispersion of the refractive indices of PTCDA and Alq 3 layers and of PTCDA/Alq3 multilayer waveguides grown on Pyrex substrates was investigated. The m-line technique, an evanescent prism coupling technique, was used to determine the layers' thickness and the in-plane (TE modes) and normal (TM modes) refractive indices. The potential for controlling the refractive index dispersion and anisotropy by tailored organic multilayer waveguides is discussed.
11. Organic crystalline films for optical applications and related methods of fabrication
Science.gov (United States)
Leyderman, Alexander (Inventor); Cui, Yunlong (Inventor)
2003-01-01
The present invention provides organic single crystal films of less than 20 .mu.m, and devices and methods of making such films. The crystal films are useful in electro-optical applications and can be provided as part of an electro-optical device which provides strength, durability, and relative ease of manipulation of the mono-crystalline films during and after crystal growth.
12. The Self-Assembly of Nano-Objects Code: Applications to supramolecular organic monolayers adsorbed on metal surfaces
CERN Document Server
Roussel, Thomas
2012-01-01
The Self-Assembly of Nano-Objects (SANO) code we implemented demonstrates the ability to predict the molecular self-assembly of different structural motifs by tuning the molecular building blocks as well as the metallic substrate. It consists in a two-dimensional Grand Canonical Monte-Carlo (GCMC) approach developed to perform atomistic simulations of thousands of large organic molecules self-assembling on metal surfaces. Computing adsorption isotherms at room temperature and spanning over the characteristic sub-micrometric scales, we confront the robustness of the approach with three different well-known systems: ZnPcCl8 on Ag(111), CuPcF16 on Au(111) and PTBC on Ag(111). We retrieve respectively their square, oblique and hexagonal supramolecular tilling. The code incorporates generalized force fields to describe the molecular interactions, which provides transferability and versatility to many organic building blocks and metal surfaces.
13. Organic and inorganic contaminants removal from water with biochar, a renewable, low cost and sustainable adsorbent--a critical review.
Science.gov (United States)
Mohan, Dinesh; Sarswat, Ankur; Ok, Yong Sik; Pittman, Charles U
2014-05-01
Biochar is used for soil conditioning, remediation, carbon sequestration and water remediation. Biochar application to water and wastewater has never been reviewed previously. This review focuses on recent applications of biochars, produced from biomass pyrolysis (slow and fast), in water and wastewater treatment. Slow and fast pyrolysis biochar production is briefly discussed. The literature on sorption of organic and inorganic contaminants by biochars is surveyed and reviewed. Adsorption capacities for organic and inorganic contaminants by different biochars under different operating conditions are summarized and, where possible, compared. Mechanisms responsible for contaminant remediation are briefly discussed. Finally, a few recommendations for further research have been made in the area of biochar development for application to water filtration. PMID:24636918
14. The Self-Assembly of Nano-Objects Code: Applications to supramolecular organic monolayers adsorbed on metal surfaces
OpenAIRE
Roussel, Thomas; Vega, Lourdes F.
2012-01-01
The Self-Assembly of Nano-Objects (SANO) code we implemented demonstrates the ability to predict the molecular self-assembly of different structural motifs by tuning the molecular building blocks as well as the metallic substrate. It consists in a two-dimensional Grand Canonical Monte-Carlo (GCMC) approach developed to perform atomistic simulations of thousands of large organic molecules self-assembling on metal surfaces. Computing adsorption isotherms at room temperature and spanning over th...
15. Computational Redox Potential Predictions: Applications to Inorganic and Organic Aqueous Complexes, and Complexes Adsorbed to Mineral Surfaces
OpenAIRE
Krishnamoorthy Arumugam; Udo Becker
2014-01-01
Applications of redox processes range over a number of scientific fields. This review article summarizes the theory behind the calculation of redox potentials in solution for species such as organic compounds, inorganic complexes, actinides, battery materials, and mineral surface-bound-species. Different computational approaches to predict and determine redox potentials of electron transitions are discussed along with their respective pros and cons for the prediction of redox potentials. Subs...
16. Biogas from MSW landfill: Composition and determination of chlorine content with the AOX (adsorbable organically bound halogens) technique
OpenAIRE
Rey Martínez, María Dolores; Font Montesinos, Rafael; Aracil, Ignacio
2013-01-01
An exhaustive characterization of the biogas from some waste disposal facilities has been carried out. The analysis includes the main components (methane, carbon dioxide, nitrogen and oxygen) as well as trace components such as hydrogen sulphide, ammonia and VOCs (volatile organic compounds) including siloxanes and halogenated compounds. VOCs were measured by GC/MS (Gas Chromatography/Mass Spectrometry) using two different procedures: thermal desorption of the Tenax TA and Carbotrap 349 tubes...
17. Structure of the Buried Metal-Molecule Interface in Organic Thin Film Devices
DEFF Research Database (Denmark)
Hansen, Christian Rein; Sørensen, Thomas Just; Glyvradal, Magni; Larsen, Jacob; Eisenhardt, Sara H.; Bjørnholm, Thomas; Nielsen, Martin Meedom; Feidenhans'l, Robert Krarup; Laursen, Bo Wegge
2009-01-01
comparison of XR data for the five-layer Pb2+ arachidate LB film before and after vapor deposition of the Ti/Al top electrode, a detailed account of the structural damage to the organic film at the buried metal-molecule interface is obtained. We find that the organized structure of the two topmost LB layers...
18. Influence of surface chemistry on the structural organization of monomolecular protein layers adsorbed to functionalized aqueous interfaces
DEFF Research Database (Denmark)
Lösche, M.; Piepenstock, M.; Diederich, A.;
1993-01-01
The molecular organization of streptavidin (SA) bound to aqueous surface monolayers of biotin-functionalized lipids and binary lipid mixtures has been investigated with neutron reflectivity and electron and fluorescence microscopy. The substitution of deuterons (2H) for protons (1H), both in...... dependence of the structural properties of such self-assembled SA monolayers on the surface chemistry was observed: the lateral protein density depends on the length of the spacer connecting the biotin moiety and its hydrophobic anchor. The hydration of the lipid head groups in the protein-bound state...
19. Organic-Inorganic Hybrid Polymers as Adsorbents for Removal of Heavy Metal Ions from Solutions: A Review
Directory of Open Access Journals (Sweden)
Babak Samiey
2014-01-01
Full Text Available Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores, assembling of nanobuilding blocks (e.g., layered or core-shell compounds and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied.
20. Electro-optical Properties of Ultra-Thin Organic Films
OpenAIRE
Hodges, Ping Y.
2001-01-01
Electro-optical properties of thin film are of great interest owing to the perpetual demand for miniaturization and higher speed devices for communication, electronic, and biomedical applications. The thickness of polymer films developed for these applications has decreased dramatically making interfacial effects significant. It is well documented that, in submicron thickness range, both film/substrate & film/air interface are critical. In this study, we probe the dynamics of electro-optic...
1. The structure of deuterated benzene films adsorbed on the graphite (0001) basal plane: what happens below and above the monolayer coverage?
OpenAIRE
Bahn, Emanuel; Hedgeland, Holly; Jardine, Andrew P.; Henry, Paul F.; Hansen, Thomas C.; Fouquet, Peter
2014-01-01
An exact description of the interactions in aromatic carbon systems is a key condition for the design of carbon based nanomaterials. In this paper we investigate the binding and adsorbate structure of the simplest prototype system in this class – the single aromatic ring molecule benzene on graphite. We have collected neutron diffraction data of the ordered phase of deuterated benzene, C6D6, adsorbed on the graphite (0001) basal plane surface. We examined relative coverages from 0.15 up to 1....
2. Structural properties of organic Langmuir-Blodgett thin films using atomic force microscopy
International Nuclear Information System (INIS)
The Langmuir-Blodgett (LB) thin film deposition technique is an elegant method in thin film technology to fabricate ultra-thin organic LB films on the nanoscale. This technique allows us to make monolayer or multilayer ultra-thin LB films by sequentially transferring monolayers from a water surface onto a solid substrate. During the last decade many scientists have a significant interest in Langmuir-Blodgett films because of potential applications of such films, which have many potential applications in physics, chemistry, biology and molecular electronics. There are a number of techniques such as Atomic Force Microscopy, Surface Plasmon Resonance, X-ray diffraction, Infra-red and Raman Spectroscopy, Ellipsometry etc that can be used to characterise and evaluate the optical and structural information of monolayer and multilayer organic LB films. In this work organic materials have been used to fabricate an ultra-thin LB film using a computer controlled alternate layer Langmuir-Blodgett trough. Atomic Force Microscopy (AFM) is employed to investigate the structural properties of such LB films. All results of the structural properties for organic ultra-thin LB films will be discussed in this paper
3. Assembly of europium organic framework–gold nanoparticle composite thin films on silicon substrate
International Nuclear Information System (INIS)
Metal organic frameworks are a sub-class of coordination polymers and rapidly generating huge research interests in several technological areas. One of the emerging areas of their potential applications is the photovoltaics. The present study proposes the assembly of europium organic framework–gold nanoparticle nanocomposite thin film on silicon substrate. Microscopic, X-ray diffraction, surface area measurement and thermal studies have indicated the formation of the desired thin film. Spectral studies have been used to highlight their solid state optical property. Current–voltage studies have established semiconducting property of the above thin films. - Highlights: • Thin film of europium organic framework/gold nanoparticles is prepared on silicon. • Fairly homogeneous films with a roughness factor of 5–10 nm are obtained. • Above thin films offer solid-state photoluminescence and semiconducting properties
4. Assembly of europium organic framework–gold nanoparticle composite thin films on silicon substrate
Energy Technology Data Exchange (ETDEWEB)
Deep, Akash, E-mail: [email protected] [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30 C, Chandigarh 160030 (India); Academy of Scientific and Innovative Research, CSIR-CSIO, Sector 30 C, Chandigarh 160030 (India); Kaur, Rajnish [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30 C, Chandigarh 160030 (India); Academy of Scientific and Innovative Research, CSIR-CSIO, Sector 30 C, Chandigarh 160030 (India); Kumar, Parveen [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30 C, Chandigarh 160030 (India); Kumar, Pawan; Paul, A.K. [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30 C, Chandigarh 160030 (India); Academy of Scientific and Innovative Research, CSIR-CSIO, Sector 30 C, Chandigarh 160030 (India)
2014-08-28
Metal organic frameworks are a sub-class of coordination polymers and rapidly generating huge research interests in several technological areas. One of the emerging areas of their potential applications is the photovoltaics. The present study proposes the assembly of europium organic framework–gold nanoparticle nanocomposite thin film on silicon substrate. Microscopic, X-ray diffraction, surface area measurement and thermal studies have indicated the formation of the desired thin film. Spectral studies have been used to highlight their solid state optical property. Current–voltage studies have established semiconducting property of the above thin films. - Highlights: • Thin film of europium organic framework/gold nanoparticles is prepared on silicon. • Fairly homogeneous films with a roughness factor of 5–10 nm are obtained. • Above thin films offer solid-state photoluminescence and semiconducting properties.
5. Computational Redox Potential Predictions: Applications to Inorganic and Organic Aqueous Complexes, and Complexes Adsorbed to Mineral Surfaces
Directory of Open Access Journals (Sweden)
Krishnamoorthy Arumugam
2014-04-01
Full Text Available Applications of redox processes range over a number of scientific fields. This review article summarizes the theory behind the calculation of redox potentials in solution for species such as organic compounds, inorganic complexes, actinides, battery materials, and mineral surface-bound-species. Different computational approaches to predict and determine redox potentials of electron transitions are discussed along with their respective pros and cons for the prediction of redox potentials. Subsequently, recommendations are made for certain necessary computational settings required for accurate calculation of redox potentials. This article reviews the importance of computational parameters, such as basis sets, density functional theory (DFT functionals, and relativistic approaches and the role that physicochemical processes play on the shift of redox potentials, such as hydration or spin orbit coupling, and will aid in finding suitable combinations of approaches for different chemical and geochemical applications. Identifying cost-effective and credible computational approaches is essential to benchmark redox potential calculations against experiments. Once a good theoretical approach is found to model the chemistry and thermodynamics of the redox and electron transfer process, this knowledge can be incorporated into models of more complex reaction mechanisms that include diffusion in the solute, surface diffusion, and dehydration, to name a few. This knowledge is important to fully understand the nature of redox processes be it a geochemical process that dictates natural redox reactions or one that is being used for the optimization of a chemical process in industry. In addition, it will help identify materials that will be useful to design catalytic redox agents, to come up with materials to be used for batteries and photovoltaic processes, and to identify new and improved remediation strategies in environmental engineering, for example the
6. Dramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materials
KAUST Repository
Nugent, Patrick
2014-07-21
The effects of pore size reduction on the dynamics of hydrogen sorption in metal-organic materials (MOMs) were elucidated by studying SIFSIX-2-Cu and its doubly interpenetrated polymorph SIFSIX-2-Cu-i by means of sorption, inelastic neutron scattering (INS), and computational modeling. SIFSIX-2-Cu-i exhibits much smaller pore sizes, which possess high H2 sorption affinity at low loadings. Experimental H2 sorption measurements revealed that the isosteric heat of adsorption (Qst) for H2 in SIFSIX-2-Cu-i is nearly two times higher than that for SIFSIX-2-Cu (8.6 vs. 4.6 kJ mol-1). The INS spectrum for H2 in SIFSIX-2-Cu-i is rather unique for a porous material, as only one broad peak appears at low energies near 6 meV, which simply increases in intensity with loading until the pores are filled. The value for this rotational transition is lower than that in most neutral metal-organic frameworks (MOFs), including those with open Cu sites (8-9 meV), which is indicative of a higher barrier to rotation and stronger interaction in the channels of SIFSIX-2-Cu-i than the open Cu sites in MOFs. Simulations of H2 sorption in SIFSIX-2-Cu-i revealed two hydrogen sorption sites in the MOM: direct interaction with the equatorial fluorine atom (site 1) and between two equatorial fluorine atoms on opposite walls (site 2). The calculated rotational energy levels and rotational barriers for the two sites in SIFSIX-2-Cu-i are in good agreement with INS data. Furthermore, the rotational barriers and binding energies for site 2 are slightly higher than that for site 1, which is consistent with INS results. The lowest calculated transition for the primary site in SIFSIX-2-Cu is also in good agreement with INS data. In addition, this transition in the non-interpenetrating material is higher than any of the sites in SIFSIX-2-Cu-i, which indicates a significantly weaker interaction with the host as a result of the larger pore size. This journal is © the Partner Organisations 2014.
7. Electromagnetic Scattering from Rough Sea Surface with PM Spectrum Covered by an Organic Film
Institute of Scientific and Technical Information of China (English)
WANG Rui; GUO Li-Xin; WANG An-Qi; WU Zhen-Sen
2011-01-01
The rough sea surface covered by an organic film will cause attenuation of capillarity waves, which implies that the organic films play an important role in rough sea surface processes. We focus on a one-dimensional(1D)rough sea surface with the Pierson-Moskowitz(PM)spectrum distributed to the homogeneous insoluble organic slicks. First, the impact of the organic film on the PM surface spectrum is presented, as well as that of the correlation length, the rms height and slope of the rough sea surface. The damping effect of the organic film changes the physical parameters of the rough sea surface. For example, the organic film will reduce the rms height and slopee of the rough sea surface, which results in the attenuation of the high-frequency components of the PM spectrum leading to modification of the surface PM spectrum. Then, the influence of the organic film on the electromagnetic(EM) scattering coefficients from PM rough sea surface covered by the organic film is investigated and discussed in detail, compared with the clean PM rough sea surface through the method of moments.
8. Electroless plating of honeycomb and pincushion polymer films prepared by self-organization.
Science.gov (United States)
Yabu, Hiroshi; Hirai, Yuji; Shimomura, Masatsugu
2006-11-01
This report describes the fabrication and electroless plating of regular porous and pincushion-like polymer structures prepared by self-organization. Honeycomb-patterned films were prepared by simple casting of polymer solution under applied humid air and pincushion structures by peeling off the top layer of the former films. Silver-deposited honeycomb-patterned films and pincushion films were obtained by simple electroless plating of the respective original structures. XPS revealed Ag deposition on the honeycomb-patterned film. After thermal decomposition or solvent elution of the template polymer, unique metal mesoscopic structures were obtained. PMID:17073508
9. Magnetic porous carbon derived from a Zn/Co bimetallic metal-organic framework as an adsorbent for the extraction of chlorophenols from water and honey tea samples.
Science.gov (United States)
Li, Menghua; Wang, Junmin; Jiao, Caina; Wang, Chun; Wu, Qiuhua; Wang, Zhi
2016-05-01
A novel magnetic porous carbon derived from a bimetallic metal-organic framework, Zn/Co-MPC, was prepared by introducing cobalt into ZIF-8. Magnetic porous carbon that possesses magnetic properties and a large specific surface area was firstly fabricated by the direct carbonization of Zn/Co-ZIF-8. The prepared magnetic porous carbon material was characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, N2 adsorption, and vibrating sample magnetometry. The prepared magnetic porous carbon was used as a magnetic solid-phase extraction adsorbent for the enrichment of chlorophenols from water and honey tea samples before high-performance liquid chromatography analysis. Several experimental parameters that could influence the extraction efficiency were investigated and optimized. Under the optimum conditions, good linearities (r > 0.9957) for all calibration curves were obtained with low limits of detection, which are in the range of 0.1-0.2 ng mL(-1) for all the analytes. The results showed that the prepared magnetic porous carbon had an excellent adsorption capability toward the target analytes. PMID:26991637
10. Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: A comparative study of waste-polymer-based,coal-based activated carbon, and carbon nanotubes
Institute of Scientific and Technical Information of China (English)
Fei Lian; Chun Chang; Yang Du; Lingyan Zhu; Baoshan Xing; Chang Liu
2012-01-01
Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE),1,3-dichlorobenzene (DCB),1,3-dinitrobenzene (DNB) and γ-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared.The adsorbents included three polymer-based activated carbons,one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT).The polymerbased activated carbons were prepared using KOH activation from waste polymers:polyvinyl chloride (PVC),polyethyleneterephthalate (PET) and tire rubber (TR).Compared with F400 and MWNT,activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs,attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures.Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect.In contrast,due to the molecular sieving effect,their adsorption on HCH was lower.MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.
11. The structure of organic langmuir films on liquid metal surfaces
International Nuclear Information System (INIS)
Langmuir films (LFs) on water have long been studied for their interest for basic science and their numerous applications in chemistry, physics, materials science and biology. We present here A-resolution synchrotron X-ray studies of the structure of stearic acid LFs on a liquid mercury surface. At low coverage, ≥110 A2/mol, a 2D gas phase of flat-lying molecules is observed. At high coverage, ≤23 A2/mol, two different hexatic phases of standing-up molecules are observed. At intermediate coverage, 52≤A≤110 A2/mol, novel single- and double-layered phases of flat-lying molecular dimers are found, exhibiting a 1D in-layer order. Such flat-lying phases were not hitherto observed in any LF. Measurements on LFs of fatty acids of other chain lengths indicate that this structure is generic to chain molecules on mercury, although the existence of some of the flat-lying phases, and the observed phase sequence, depend on the chain length. Organic LFs on Hg, and in particular the new flat-lying phases, should provide a broader nano-structural tunability range for molecular electronic device construction than most solid-supported self-assembled monolayers used at present
12. Perylene Diimide Based Nanofabric'' Thin Films for Organic Photovoltaic Cells
Science.gov (United States)
Carter, Austin; Park, June Hyoung; Min, Yong; Epstein, Arthur
2011-03-01
We report progress in using a perylene diimide (PDI) nanofabric as an effective electron accepting nanostructure for organic photovoltaics (OPV). A key challenge in OPV continues to be the recovery of electrons after charge separation due to the relatively poor mobility of C60 and related materials. A series of PDI compounds and complexes have been synthesized and used to fabricate nanofibers and thin films using solution and vacuum deposition techniques. Overlaping PDI-based nanofibers form a fast electron-transporting nanofabric'' that has been characterized (AFM, PL, UV-vis, etc.) and can be blended with electron donating materials. A solution-processible OPV configuration containing a nanofabric heterojunction (FHJ) of poly(3-hexylthiophene) and the PDI nanofabric was investigated. We observed a significant improvement in power-conversion efficiency due in part to expansion of the interfacial area and the presence of high mobility electron pathways to the LiF/Al electrode. This work is supported by the Wright Center for Photovoltaic Innovation and Commercialization, the Institute for Materials Research and the Center for Affordable Nanoengineering of Polymeric Biomedical Devices.
13. Metal–organic coordinated multilayer film formation: Quantitative analysis of composition and structure
International Nuclear Information System (INIS)
Metal–organic coordinated multilayers are self-assembled thin films fabricated by alternating solution–phase deposition of bifunctional organic molecules and metal ions. The multilayer film composed of α,ω-mercaptoalkanoic acid and Cu (II) has been the focus of fundamental and applied research with its robust reproducibility and seemingly simple hierarchical architecture. However, internal structure and composition have not been unambiguously established. The composition of films up to thirty layers thick was investigated using Rutherford backscattering spectrometry and particle induced X-ray emission. Findings show these films are copper enriched, elucidating a 2:1 ratio for the ion to molecule complexation at the metal–organic interface. Results also reveal that these films have an average layer density similar to literature values established for a self-assembled monolayer, indicating a robust and stable structure. The surface structures of multilayer films have been characterized by contact angle goniometry, ellipsometry, and scanning probe microscopy. A morphological transition is observed as film thickness increases from the first few foundational layers to films containing five or more layers. Surface roughness analysis quantifies this evolution as the film initially increases in roughness before obtaining a lower roughness comparable to the underlying gold substrate. Quantitative analysis of topographical structure and internal composition for metal–organic coordinated multilayers as a function of number of deposited layers has implications for their incorporation in the fields of photonics and nanolithography. - Highlights: • Layer-by-layer deposition is examined by scanning probe microscopy and ion beam analysis. • Film growth undergoes morphological evolution during foundational layer deposition. • Image analysis quantified surface features such as roughness, grain size, and coverage. • Molecular density of each film layer is found to
14. Protection of MoO{sub 3} high work function by organic thin film
Energy Technology Data Exchange (ETDEWEB)
Wang, Chenggong; Irfan, Irfan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Gao, Yongli [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Institute for Super-microstructure and Ultrafast Process in Advanced Materials (ISUPAM), Central South University, Changsha, Hunan 410083 (China)
2014-11-03
The effects of air exposure are investigated for molybdenum trioxide (MoO{sub 3}) covered with organic thin films using ultraviolet photoemission spectroscopy. It is found that the severe drop of the work function of MoO{sub 3} by air exposure is substantially reduced by the organic thin films. Both CuPc and C{sub 60} are used for the investigations. The results indicate that the MoO{sub 3} surface can be passivated by approximately two monolayers of organic thin films against exposure to air.
15. Fluorescence dynamics of microsphere-adsorbed sunscreens
Science.gov (United States)
Krishnan, R.
2005-03-01
Sunscreens are generally oily substances which are prepared in organic solvents, emulsions or dispersions with micro- or nanoparticles. These molecules adsorb to and integrate into skin cells. In order to understand the photophysical properties of the sunscreen, we compare steady-state and time-resolved fluorescence in organic solvent of varying dielectric constant ɛ and adsorbed to polystyrene microspheres and dispersed in water. Steady-state fluorescence is highest and average fluorescence lifetime longest in toluene, the solvent of lowest ɛ. However, there is no uniform dependence on ɛ. Sunscreens PABA and padimate-O show complex emission spectra. Microsphere-adsorbed sunscreens exhibit highly non-exponential decay, illustrative of multiple environments of the adsorbed molecule. The heterogeneous fluorescence dynamics likely characterizes sunscreen adsorbed to cells.
16. Organic ultrathin film adhesion on compliant substrate using scratch test technique
OpenAIRE
Boddaert, Xavier; Covarel, Grégory; Ben Saïd, Bassem; Mattei, Mylene; Benaben, Patrick; Bois, Jérôme
2012-01-01
International audience Many adhesion test techniques have been developed to measure the adhesion energy of thin films but they are hard to implement in the case of submicron organic thin films deposited on a flexible substrate. Recently the feasibility and repeatability of the scratch test technique as a tool for testing the adhesion and the damage behaviour of ultra-thin films on polymer substrates has been demonstrated. However, direct comparison of the critical load between samples was ...
17. Deposition of metal oxide films and nanostructures by methods derived from photochemical metal organic deposition
OpenAIRE
Xin ZHANG
2009-01-01
In this research, methods for the deposition of patterned films and nanostructures were developed from photochemical metal organic deposition (PMOD). Positive lithographic PMOD was demonstrated with films of titanium (IV) di-n-butoxide bis(2-ethylhexanoate) (Ti(OBun)2(eh)2), titanium (IV) diisopropoxide bis(2,4-pentanedionate), and zirconium (IV) di-n-butoxide bis(2,4-pentanedionate). The photochemistry of these complexes in films was studied by FTIR, AES, and XRD. Photo-induced reactivity an...
18. Comparison of physicomechanical properties of films prepared from organic solutions and aqueous dispersion of Eudragit RL
OpenAIRE
H Afrasiabi Garekani; M. Shahabi; F Sadeghi
2011-01-01
Background and the purpose of the study: Mechanical properties of films prepared from aqueous dispersion and organic solutions of Eudragit RL were assessed and the effects of plasticizer type, concentration and curing were examined. Methods: Films were prepared from aqueous dispersion and solutions of Eudragit RL (isopropyl alcohol-water 9:1) containing 0, 10 or 20% (based on polymer weight) of PEG 400 or Triethyl Citrate (TEC) as plasticizer using casting method. Samples of films were stored...
19. Mesoscale control of organic crystalline thin films: effects of film morphology on the performance of organic transistors
Energy Technology Data Exchange (ETDEWEB)
Kim, Jaekyun; Park, Sungkyu [Chung-Ang University, Seoul (Korea, Republic of); Kim, Yonghoon [Sungkyunkwan University, Suwon (Korea, Republic of)
2014-08-15
We report mesoscale control of small molecular 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) crystalline thin films by varying the solute concentration in the fluidic channel method. A stepwise increase in the TIPS-pentacene concentration in the solution enabled us to prepare highly-crystallized ribbons, thin films, and thick films in a mesoscale range, respectively. All three types of deposited films exhibited an in-plane crystalline nature of (001) direction being normal to the substrate as well as crystalline domain growth parallel to the direction of the receding meniscus inside the fluidic channel. In addition, the film's morphology and thickness were found to have a great influence on the field-effect mobility of the transistors, and the highest average and maximum mobilities were achieved from transistors with thin-film semiconductor channels.
20. Erbium-doped yttria thin films prepared by metal organic decomposition for up-conversion
International Nuclear Information System (INIS)
Er:Y2O3 thin films have been obtained by spin coating process. Precursor solutions were prepared using nitrates as metal precursors and water as solvent. Citric, malic, and lactic acids were used as complexant. Investigations on resin compositions and on their coating parameters have been made, leading to crack-free thin films with citric and malic acids after direct deposition under standard room conditions (temperature, pressure and atmosphere). The films are homogeneous with a low root mean square roughness, less than 2.5 nm. We demonstrated that the nature of the carboxylic acid is the key point to obtain high quality thin films on silicon substrates from 20 nm up to 230 nm thick, while the film porosity is related to the number of carbon in the acid molecule. All films exhibit up-conversion luminescence in the near infrared and in the visible range, under 1.54 μm laser excitation. Furthermore, the up-conversion luminescence intensity increases with the applied annealing temperature on the films, due to an improvement of their crystallinity and to the total decomposition of organics. - Highlights: • We deposit films by spin-coating, using aqueous precursor solutions. • No special control of atmosphere is needed during all the process. • The organics are the key parameter for controlling the quality of films. • Multilayer have been obtained with all carboxylic acids we have studied. • All films exhibit an up-conversion property
1. Erbium-doped yttria thin films prepared by metal organic decomposition for up-conversion
Energy Technology Data Exchange (ETDEWEB)
Andriamiadamanana, Christian, E-mail: [email protected] [LCMCP UMR7574 CNRS/UPMC/Chimie Paristech, 11 Rue Pierre et Marie Curie, F-75235 Paris (France); IRDEP, UMR 7174 CNRS/EDF/Chimie ParisTech, 6 Quai Watier, F-78401 Chatou (France); Ibanez, Alain [Institut Néel, UPR2940, CNRS/Université Joseph Fourier, 25 rue des Martyrs, BP166, F-38042, Grenoble Cedex 9 (France); Ferrier, Alban [LCMCP UMR7574 CNRS/UPMC/Chimie Paristech, 11 Rue Pierre et Marie Curie, F-75235 Paris (France); Joudrier, Anne-Laure [LCMCP UMR7574 CNRS/UPMC/Chimie Paristech, 11 Rue Pierre et Marie Curie, F-75235 Paris (France); IRDEP, UMR 7174 CNRS/EDF/Chimie ParisTech, 6 Quai Watier, F-78401 Chatou (France); Lombez, Laurent [IRDEP, UMR 7174 CNRS/EDF/Chimie ParisTech, 6 Quai Watier, F-78401 Chatou (France); Liotaud, Marine [Institut Néel, UPR2940, CNRS/Université Joseph Fourier, 25 rue des Martyrs, BP166, F-38042, Grenoble Cedex 9 (France); Guillemoles, Jean-François [IRDEP, UMR 7174 CNRS/EDF/Chimie ParisTech, 6 Quai Watier, F-78401 Chatou (France); Pellé, Fabienne [LCMCP UMR7574 CNRS/UPMC/Chimie Paristech, 11 Rue Pierre et Marie Curie, F-75235 Paris (France)
2013-06-30
Er:Y{sub 2}O{sub 3} thin films have been obtained by spin coating process. Precursor solutions were prepared using nitrates as metal precursors and water as solvent. Citric, malic, and lactic acids were used as complexant. Investigations on resin compositions and on their coating parameters have been made, leading to crack-free thin films with citric and malic acids after direct deposition under standard room conditions (temperature, pressure and atmosphere). The films are homogeneous with a low root mean square roughness, less than 2.5 nm. We demonstrated that the nature of the carboxylic acid is the key point to obtain high quality thin films on silicon substrates from 20 nm up to 230 nm thick, while the film porosity is related to the number of carbon in the acid molecule. All films exhibit up-conversion luminescence in the near infrared and in the visible range, under 1.54 μm laser excitation. Furthermore, the up-conversion luminescence intensity increases with the applied annealing temperature on the films, due to an improvement of their crystallinity and to the total decomposition of organics. - Highlights: • We deposit films by spin-coating, using aqueous precursor solutions. • No special control of atmosphere is needed during all the process. • The organics are the key parameter for controlling the quality of films. • Multilayer have been obtained with all carboxylic acids we have studied. • All films exhibit an up-conversion property.
2. Highly Crystalline Films of Organic Small Molecules with Alkyl Chains Fabricated by Weak Epitaxy Growth.
Science.gov (United States)
Zhu, Yangjie; Chen, Weiping; Wang, Tong; Wang, Haibo; Wang, Yue; Yan, Donghang
2016-05-12
Because side-chain engineering of organic conjugated molecules has been widely utilized to tune organic solid-state optoelectronic properties, the achievement of their high-quality films is important for realizing high-performance devices. Here, highly crystalline films of an organic molecule with short alkyl chains, 5,8,15,18-tetrabutyl-5,8,15,18-tetrahydroindolo[3,2-a]indole[30,20:5,6]quinacridone (C4-IDQA), are fabricated by weak epitaxy growth, and highly oriented, large-area, and continuous films are obtained. Because of the soft matter properties, the C4-IDQA molecules can adjust themselves to realize commensurate epitaxy growth on the inducing layers and exhibited good lattice matching in the thin film phase. The crystalline phase is also observed in thicker C4-IDQA films. The growth behavior of C4-IDQA on the inducing layer is further investigated, including the strong dependence of film morphologies on substrate temperatures and deposition rates due to the poor diffusion ability of C4-IDQA molecules. Moreover, highly crystalline films and high electron field-effect mobility are also obtained for the small molecule N,N'-dioctyl-3,4:9,10-perylene tetracarboxylic diimide (C8-PTCDI), which demonstrate that the weak epitaxy growth method could be an effective way to fabricate highly crystalline films of organic small molecules with flexible side chains. PMID:27116036
3. Properties of alumina films by atmospheric pressure metal-organic chemical vapour deposition
NARCIS (Netherlands)
Haanappel, V.A.C.; Corbach, van H.D.; Fransen, T.; Gellings, P.J.
1994-01-01
Thin alumina films were deposited at low temperatures (290–420°C) on stainless steel, type AISI 304. The deposition process was carried out in nitrogen by metal-organic chemical vapour deposition using aluminum tri-sec-butoxide. The film properties including the protection of the underlying substrat
4. Using Organic Light-Emitting Electrochemical Thin-Film Devices to Teach Materials Science
Science.gov (United States)
Sevian, Hannah; Muller, Sean; Rudmann, Hartmut; Rubner, Michael F.
2004-01-01
Materials science can be taught by applying organic light-emitting electrochemical thin-film devices and in this method students were allowed to make a light-emitting device by spin coating a thin film containing ruthenium (II) complex ions onto a glass slide. Through this laboratory method students are provided with the opportunity to learn about…
5. Organization of copper nanoclusters in Langmuir–Blodgett films
Indian Academy of Sciences (India)
G Hemakanthi; Aruna Dhathathreyan; T Ramasami
2002-02-01
Stable nanoclusters of Cu were synthesized using Langmuir–Blodgett films of octadecylsuccinic acid (ODSA) as template. The Langmuir–Blodgett films of ODSA formed from subphase containing copper ions were first subjected to sulphidation (S) using sodium sulphide and then hydrogenated (H) using hydrogen gas. Diffuse reflectance UV-visible spectroscopy (DIR-UV-vis), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) used to characterize these films indicated the formation of Cu(0) metallic clusters ranging in size from 3 ∼ 10 nm.
6. Organic-organic interfaces and unoccupied electronic states of thin films of perylene and naphthalene derivatives
DEFF Research Database (Denmark)
Kamounah, Fadhil S.; Komolov, A.S; Juul Møller, Preben;
2005-01-01
,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA, Fig. 1c) film surfaces, respectively, in order to form organic–organic interfaces so that molecules constituting the interfacing layers differ by the substituent group. The surface potential and the density of unoccupied electron states (DOUS) located 5–25 eV above the Fermi...... level (EF) were measured during the film deposition using an incident beam of low-energy electrons according to the total current electron spectroscopy (TCS) method. Analysis of the TCS data allowed us to assign the π( band located 5–7.5 eV above EF for all the four films under study and the higher...
7. Influence of organic films on the evaporation and condensation of water in aerosol
OpenAIRE
Davies, James F.; Miles, Rachael E H; Haddrell, Allen E; Reid, Jonathan P.
2013-01-01
Uncertainties in quantifying the kinetics of evaporation and condensation of water fromatmospheric aerosol are a significant contributor to the uncertainty in predicting cloud droplet number and the indirect effect of aerosols on climate. The influence of aerosol particle surface composition, particularly the impact of surface active organic films, on the condensation and evaporation coefficients remains ambiguous. Here, we report measurements of the influence of organic films on the evaporat...
8. Adaptive hydrophobic and hydrophilic interactions of mussel foot proteins with organic thin films
OpenAIRE
Yu, J; Kan, Y.; M. Rapp; Danner, E; Wei, W.; Das, S.; Miller, DR; Chen, Y.; Waite, JH; Israelachvili, JN
2013-01-01
The adhesion of mussel foot proteins (Mfps) to a variety of specially engineered mineral and metal oxide surfaces has previously been investigated extensively, but the relevance of these studies to adhesion in biological environments remains unknown. Most solid surfaces exposed to seawater or physiological fluids become fouled by organic conditioning films and biofilms within minutes. Understanding the binding mechanisms of Mfps to organic films with known chemical and physical properties the...
9. Combinatorial Techniques to Efficiently Investigate and Optimize Organic Thin Film Processing and Properties
OpenAIRE
Hans-Werner Schmidt; Ober, Christopher K.; Christian Neuber; Tristan Kolb; Florian Wieberger
2013-01-01
In this article we present several developed and improved combinatorial techniques to optimize processing conditions and material properties of organic thin films. The combinatorial approach allows investigations of multi-variable dependencies and is the perfect tool to investigate organic thin films regarding their high performance purposes. In this context we develop and establish the reliable preparation of gradients of material composition, temperature, exposure, and immersion time. Furth...
10. Organic thin film field effect transistor made with soluble Al(OH) phthalocyanine
Czech Academy of Sciences Publication Activity Database
Janus, K.; Lutsyk, P.; Nešpůrek, Stanislav
Wroclaw: Oficyna Wydawnicza Politechniki Wroclawskiej, 2008. s. 76. ISBN 978-83-7493-399-5. [International Conference on Electrical and Related Properties of Organic Solids /11./. 13.07.2008-17.07.2008, Piechowice] R&D Projects: GA AV ČR KAN401770651 EU Projects: European Commission(XE) 35859 - BIMORE Institutional research plan: CEZ:AV0Z40500505 Keywords : organic thin film * phthalocyanine film s * field effect transistor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
11. Pulsed injection metal organic chemical vapour deposition and characterisation of thin CaO films
International Nuclear Information System (INIS)
Thin films of CaO were grown on silicon (Si) and lanthanum aluminate (LaAlO3) substrates by pulsed injection metal-organic chemical vapour deposition in a vertical injection MOCVD system. Growth parameters were systematically varied to study their effect on film growth and quality and to determine the optimal growth conditions for this material. Film quality and growth rate were evaluated by atomic force microscopy, X-ray diffraction and Rutherford Backscattering Spectroscopy measurements. Optimised conditions allowed growing transparent, single phase films textured along the (0 0 l) direction.
12. Adhesive flexible barrier film, method of forming same, and organic electronic device including same
Energy Technology Data Exchange (ETDEWEB)
Blizzard, John Donald; Weidner, William Kenneth
2013-02-05
An adhesive flexible barrier film comprises a substrate and a barrier layer disposed on the substrate. The barrier layer is formed from a barrier composition comprising an organosilicon compound. The adhesive flexible barrier film also comprises an adhesive layer disposed on the barrier layer and formed from an adhesive composition. A method of forming the adhesive flexible barrier film comprises the steps of disposing the barrier composition on the substrate to form the barrier layer, disposing the adhesive composition on the barrier layer to form the adhesive layer, and curing the barrier layer and the adhesive layer. The adhesive flexible barrier film may be utilized in organic electronic devices.
13. Adsorbate-modified growth of ultrathin rare-earth oxide films on silicon and complementary studies of cerium oxide on ruthenium; Adsorbat-modifiziertes Wachstum ultraduenner Seltenerdoxid-Filme auf Silizium und komplementaere Studien von Ceroxid auf Ruthenium
Energy Technology Data Exchange (ETDEWEB)
Kaemena, Bjoern
2013-11-27
Rare-earth oxides (REOx) are extensively investigated due to their extraordinary physical and chemical properties, which essentially arise from the unfilled 4f electron shell, in order to reveal the nature of these exceptional properties and ultimately to utilize them for multiple technological applications. To maintain the exponential increase in integration density in CMOS technology, which is also known as Moore s law, there is a strong desire for ultrathin, well-ordered, epitaxial REOx layers with a precisely engineered interface, which is essential for reliable, ultrahigh-performance devices. So far this has been considerably impeded by RE-promoted silicon oxidation, leading to amorphous silicon oxide and RE silicon formation. By using complementary synchrotron radiation methods such as X-ray standing waves (XSW), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), structural and spectroscopic information are inferred simultaneously from ultrathin ceria and lanthana films grown on chlorine, silver and gallium passivated silicon(111). In general, it is revealed that the chemical and structural composition of the interface and the crystallinity of ultrathin REOx layers on silicon can be precisely controlled by adsorbate-mediated growth. This might represent a crucial step towards a perfectly engineered interface, eventually allowing for the integration of REOx as high-k gate oxides in microelectronics. In catalysis inverse model catalysts are studied with the aim of getting an in-depth understanding of the basic principles of catalysis. These model systems are employed to study, e. g., the nature of active sites and the reaction pathways in complex catalytic converters. However, a lot remains unknown about the chemical activity and selectivity as a function of the growth mechanism, structure and morphology of these model systems. The powerful spectroscopic photoemission and low-energy electron microscope, which is able to reveal the surface
14. Organic ferroelectric gate field-effect transistor memory using high-mobility rubrene thin film
Science.gov (United States)
Kanashima, Takeshi; Katsura, Yuu; Okuyama, Masanori
2014-01-01
An organic ferroelectric gate field-effect transistor (FET) memory has been fabricated using an organic semiconductor of rubrene thin film with a high mobility and a gate insulating layer of poly(vinylidene fluoride-tetrafluoroethylene) [P(VDF-TeFE)] thin film. A rubrene thin-film sheet was grown by physical vapor transport (PVT), and placed onto a spin-coated P(VDF-TeFE) thin-film layer, and Au source and drain electrodes were formed on this rubrene thin film. A hysteresis loop of the drain current-gate voltage (ID-VG) characteristic has been clearly observed in the ferroelectric gate FET, and is caused by the ferroelectricity. The maximum drain current is 1.5 × 10-6 A, which is about two orders of magnitude larger than that of the P(VDF-TeFE) gate FET using a pentacene thin film. Moreover, the mobility of this organic ferroelectric gate FET using rubrene thin film is 0.71 cm2 V-1 s-1, which is 35 times larger than that of the FET with pentacene thin film.
15. Processing and performance of organic insulators as a gate layer in organic thin film transistors fabricated on polyethylene terephthalate substrate
Indian Academy of Sciences (India)
Saumen Mandal; Monica Katiyar
2013-08-01
Fabrication of organic thin film transistor (OTFT) on flexible substrates is a challenge, because of its low softening temperature, high roughness and flexible nature. Although several organic dielectrics have been used as gate insulator, it is difficult to choose one in absence of a comparative study covering processing of dielectric layer on polyethylene terephthalate (PET), characterization of dielectric property, pentacene film morphology and OTFT characterization. Here, we present the processing and performance of three organic dielectrics, poly(4-vinylphenol) (PVPh), polyvinyl alcohol (PVA) and poly(methylmethacrylate) (PMMA), as a gate layer in pentacene-based organic thin film transistor on PET substrate. We have used thermogravimetric analysis of organic dielectric solution to determine annealing temperature for spin-coated films of these dielectrics. Comparison of the leakage currents for the three dielectrics shows PVA exhibiting lowest leakage (in the voltage range of −30 to +30 V). This is partly because solvent is completely eliminated in the case of PVA as observed by differential thermogravimetric analysis (DTGA). We propose that DTGA can be a useful tool to optimize processing of dielectric layers. From organic thin film transistor point of view, crystal structure, morphology and surface roughness of pentacene film on all the dielectric layers were studied using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM).We observe pyramidal pentacene on PVPh whereas commonly observed dendritic pentacene on PMMA and PVA surface. Pentacene morphology development is discussed in terms of surface roughness, surface energy and molecular nature of the dielectric layer.
16. Characterisation of molecular thin films grown by organic molecular beam deposition
CERN Document Server
Bayliss, S M
2000-01-01
This work concerns the growth and characterisation of molecular thin films in an ultra high vacuum regime by organic molecular beam deposition (OMBD). Films of three different molecular materials are grown, namely free base phthalocyanine (H sub 2 Pc), perylene 3,4,9,10-tetracarboxylic dianhydride (PTCDA) and aluminium tris-8-hydroxyquinoline (Alq sub 3). The relationship between the growth parameters such as film thickness, growth rate, and substrate temperature during and after growth, and the structural, optical and morphological properties of the film are investigated. These investigations are carried out using various ex-situ techniques. X-ray diffraction, Raman spectroscopy and electronic absorption spectroscopy are used to probe the bulk film characteristics, whilst Nomarski microscopy and atomic force microscopy are used to study the surface morphology. Three different levels of influence of the growth parameters on the film properties are observed. In the case of H sub 2 Pc, two crystal phases are fo...
17. Detection of volatile organic compounds using optical fibre long period grating modified with metal organic framework thin films
Science.gov (United States)
Hromadka, Jiri; Tokay, Begum; Korposh, Sergiy; James, Stephen; Tatam, Ralph P.
2015-09-01
An optical fibre long period grating (LPG) modified with a thin film of ZIF-8, a zeolitic immidazol framework (ZIF) material, a subgroup of the metal organic framework (MOF) family, was employed for the detection of organic vapours. ZIF-8 film was deposited onto the surface of the LPG using an in-situ crystallization technique. The sensing mechanism is based on the measurement of the refractive index (RI) change induced by the penetration of the chemical molecules into the ZIF-8 pores. An LPG modified with 5 growth cycles of ZIF-8 responded to exposure to methanol and ethanol vapours.
18. Tracing the 4000 year history of organic thin films: From monolayers on liquids to multilayers on solidsa)
Science.gov (United States)
Greene, J. E.
2015-03-01
The recorded history of organic monolayer and multilayer thin films spans approximately 4000 years. Fatty-acid-based monolayers were deposited on water by the ancients for applications ranging from fortune telling in King Hammurabi's time (˜1800 BC, Mesopotamia) to stilling choppy waters for sailors and divers as reported by the Roman philosopher Pliny the Elder in ˜78 AD, and then much later (1774) by the peripatetic American statesman and natural philosopher Benjamin Franklin, to Japanese "floating-ink" art (suminagashi) developed ˜1000 years ago. The modern science of organic monolayers began in the late-1800s/early-1900s with experiments by Lord Rayleigh and the important development by Agnes Pockels, followed two decades later by Irving Langmuir, of the tools and technology to measure the surface tension of liquids, the surface pressure of organic monolayers deposited on water, interfacial properties, molecular conformation of the organic layers, and phase transitions which occur upon compressing the monolayers. In 1935, Katherine Blodgett published a landmark paper showing that multilayers can be synthesized on solid substrates, with controlled thickness and composition, using an apparatus now known as the Langmuir-Blodgett (L-B) trough. A disadvantage of LB films for some applications is that they form weak physisorbed bonds to the substrate. In 1946, Bigelow, Pickett, and Zisman demonstrated, in another seminal paper, the growth of organic self-assembled monolayers (SAMs) via spontaneous adsorption from solution, rather than from the water/air interface, onto SiO2 and metal substrates. SAMs are close-packed two-dimensional organic crystals which exhibit strong covalent bonding to the substrate. The first multicomponent adsorbed monolayers and multilayer SAMs were produced in the early 1980s. Langmuir monolayers, L-B multilayers, and self-assembled mono- and multilayers have found an extraordinarily broad range of applications including controlled wetting
19. Tracing the 4000 year history of organic thin films: From monolayers on liquids to multilayers on solids
Energy Technology Data Exchange (ETDEWEB)
Greene, J. E. [University of Illinois, Urbana, Illinois 61801 (United States); Linköping University, 581 83 Linköping (Sweden); National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)
2015-03-15
The recorded history of organic monolayer and multilayer thin films spans approximately 4000 years. Fatty-acid-based monolayers were deposited on water by the ancients for applications ranging from fortune telling in King Hammurabi's time (∼1800 BC, Mesopotamia) to stilling choppy waters for sailors and divers as reported by the Roman philosopher Pliny the Elder in ∼78 AD, and then much later (1774) by the peripatetic American statesman and natural philosopher Benjamin Franklin, to Japanese “floating-ink” art (suminagashi) developed ∼1000 years ago. The modern science of organic monolayers began in the late-1800s/early-1900s with experiments by Lord Rayleigh and the important development by Agnes Pockels, followed two decades later by Irving Langmuir, of the tools and technology to measure the surface tension of liquids, the surface pressure of organic monolayers deposited on water, interfacial properties, molecular conformation of the organic layers, and phase transitions which occur upon compressing the monolayers. In 1935, Katherine Blodgett published a landmark paper showing that multilayers can be synthesized on solid substrates, with controlled thickness and composition, using an apparatus now known as the Langmuir-Blodgett (L-B) trough. A disadvantage of LB films for some applications is that they form weak physisorbed bonds to the substrate. In 1946, Bigelow, Pickett, and Zisman demonstrated, in another seminal paper, the growth of organic self-assembled monolayers (SAMs) via spontaneous adsorption from solution, rather than from the water/air interface, onto SiO{sub 2} and metal substrates. SAMs are close-packed two-dimensional organic crystals which exhibit strong covalent bonding to the substrate. The first multicomponent adsorbed monolayers and multilayer SAMs were produced in the early 1980s. Langmuir monolayers, L-B multilayers, and self-assembled mono- and multilayers have found an extraordinarily broad range of applications including
20. Tracing the 4000 year history of organic thin films: From monolayers on liquids to multilayers on solids
International Nuclear Information System (INIS)
The recorded history of organic monolayer and multilayer thin films spans approximately 4000 years. Fatty-acid-based monolayers were deposited on water by the ancients for applications ranging from fortune telling in King Hammurabi's time (∼1800 BC, Mesopotamia) to stilling choppy waters for sailors and divers as reported by the Roman philosopher Pliny the Elder in ∼78 AD, and then much later (1774) by the peripatetic American statesman and natural philosopher Benjamin Franklin, to Japanese “floating-ink” art (suminagashi) developed ∼1000 years ago. The modern science of organic monolayers began in the late-1800s/early-1900s with experiments by Lord Rayleigh and the important development by Agnes Pockels, followed two decades later by Irving Langmuir, of the tools and technology to measure the surface tension of liquids, the surface pressure of organic monolayers deposited on water, interfacial properties, molecular conformation of the organic layers, and phase transitions which occur upon compressing the monolayers. In 1935, Katherine Blodgett published a landmark paper showing that multilayers can be synthesized on solid substrates, with controlled thickness and composition, using an apparatus now known as the Langmuir-Blodgett (L-B) trough. A disadvantage of LB films for some applications is that they form weak physisorbed bonds to the substrate. In 1946, Bigelow, Pickett, and Zisman demonstrated, in another seminal paper, the growth of organic self-assembled monolayers (SAMs) via spontaneous adsorption from solution, rather than from the water/air interface, onto SiO2 and metal substrates. SAMs are close-packed two-dimensional organic crystals which exhibit strong covalent bonding to the substrate. The first multicomponent adsorbed monolayers and multilayer SAMs were produced in the early 1980s. Langmuir monolayers, L-B multilayers, and self-assembled mono- and multilayers have found an extraordinarily broad range of applications including
1. Water Pollution and Treatments Part I: Evaluation of Organic, Inorganic and Marine Products as Adsorbents For Petroleum Pollutants Present In Aqueous Wastes
International Nuclear Information System (INIS)
The main objective of the present work is to perform a comparative laboratory study using an adsorption technique for oil removal from the waste water drained to sea from refineries, offshore and/or onshore petroleum installations. Different crushed adsorbent materials, namely, cotton fibers, charcoal, petroleum coke, agriculture wastes (such as, rice straws, wheat stems, milled dry leaves and lignin), inorganic adsorbents (such as sand, and bricks) and a marine Product (such as sponge) are included in this study. They were tested for oil recovery from laboratory prepared oily salt water samples. Two different Egyptian crude oils varying in their properties and several refined products (gasoline, kerosene, gas oil, diesel oil, fuel oil, lubricating oil) and skimmed oil were employed. Their adsorptive efficiencies were tested. Good results were obtained with sponge and cotton fibers. The used agricultural wastes show better adsorption compared with coke and inorganic adsorbents.
2. A flexible organic active matrix circuit fabricated using novel organic thin film transistors and organic light-emitting diodes
KAUST Repository
Gutiérrez-Heredia, Gerardo
2010-10-04
We present an active matrix circuit fabricated on plastic (polyethylene naphthalene, PEN) and glass substrates using organic thin film transistors and organic capacitors to control organic light-emitting diodes (OLEDs). The basic circuit is fabricated using two pentacene-based transistors and a capacitor using a novel aluminum oxide/parylene stack (Al2O3/ parylene) as the dielectric for both the transistor and the capacitor. We report that our circuit can deliver up to 15 μA to each OLED pixel. To achieve 200 cd m-2 of brightness a 10 μA current is needed; therefore, our approach can initially deliver 1.5× the required current to drive a single pixel. In contrast to parylene-only devices, the Al2O 3/parylene stack does not fail after stressing at a field of 1.7 MV cm-1 for >10 000 s, whereas \\'parylene only\\' devices show breakdown at approximately 1000 s. Details of the integration scheme are presented. © 2010 IOP Publishing Ltd.
3. In-Line Sputtered Gallium and Aluminum Codoped Zinc Oxide Films for Organic Solar Cells
Directory of Open Access Journals (Sweden)
Shang-Chou Chang
2014-01-01
Full Text Available Gallium and aluminum codoped zinc oxide (GAZO films were deposited at different temperatures by in-line sputtering. Aluminum is thermally unstable compared to other elements in GAZO films. The grains of GAZO films increase with deposition temperature. Coalescence between grains was observed for GAZO films deposited at 250°C. The deposition temperature exhibits positive influence on crystallinity, and electrical and optical properties of GAZO films. The carrier concentration and mobility of GAZO films increase, while the electrical resistivity of GAZO films decreases with deposition temperature. The average optical transmittance of GAZO films rises with deposition temperature. In-line sputtering demonstrates a potential method with simplicity, mass production, and large-area deposition to produce GAZO films with good electrical and optical quality. The electrical resistivity of 4.3 × 10−4 Ω cm and the average optical transmittance in the visible range from 400 to 800 nm of 92% can be obtained for GAZO films deposited at 250°C. The hybrid organic solar cells (OSC were fabricated on GAZO-coated glass substrates. Blended poly(3-hexylthiophene (P3HT and [6,6]-phenyl C61 butyric acid methyl ester (PCBM were the photoactive materials in OSC. The power conversion efficiency of OSC is 0.65% for the OSC with the 250°C deposited GAZO electrode.
4. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition
Energy Technology Data Exchange (ETDEWEB)
Liang, Yangang; Zhang, Xiaohang; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Takeuchi, Ichiro, E-mail: [email protected] [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); Yao, Yangyi; Hsu, Wei-Lun; Dagenais, Mario [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20740 (United States)
2016-01-15
We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.
5. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition
International Nuclear Information System (INIS)
We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH3NH3PbI3 thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure
6. The Dynamics and Structures of Adsorbed Surfaces
DEFF Research Database (Denmark)
Nielsen, M; Ellenson, W. D.; McTague, J. P.
1978-01-01
Reviews neutron scattering work performed on films of simple gas atoms and molecules adsorbed primarily on graphite surfaces. Exfoliated graphite substrates such as Grafoil were first used in this kind of measurements about five years ago and new results have been reported at an increasing pace. ...
7. Study of intermolecular interactions in hetero-organic thin films
OpenAIRE
2013-01-01
The interest in organic semiconductors is based on their great potential to serve as active materials in electronic devices such as organic light-emitting diodes or organic photovoltaic cells. The performance of these molecular assemblies does not only depend on the properties of the organic bulk materials but also on the interfaces formed by the contact between different materials. Therefore, the physical properties of interfaces between metal contacts and organic materials have been studied...
8. In situ ellipsometry — A powerful tool for monitoring alkali doping of organic thin films
Energy Technology Data Exchange (ETDEWEB)
Haidu, F.; Ludemann, M.; Schäfer, P.; Gordan, O.D., E-mail: [email protected]; Zahn, D.R.T.
2014-11-28
The changes of the optical properties of several organic thin films induced by potassium doping were monitored using in situ spectroscopic ellipsometry. The samples were prepared in a high vacuum chamber by organic molecular deposition. Then, potassium (K) was evaporated by passing current through K getters. The three different organic molecules used, show very distinct and different spectral behaviour upon doping. While for Tris-(8-hydroxyquinoline)-aluminium(III) and N,N′-Di-[(1-naphthyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4,4′-diamine only small shifts of the spectral features were noticed, Manganese Phthalocyanine revealed significant changes of the optical properties induced by the K doping. This work indicates that the K doping process can have a dramatic effect on the electronic and the optical properties of the organic molecules, but the effect on the optical spectra remains specific for each organic molecule used, and cannot be easily predicted. - Highlights: • Monitoring organic film growth and doping with in situ spectroscopic ellipsometry • K doped organic thin films • Optical properties of organic thin films change by K doping. • The changes in the optical spectra remain specific for each organic molecule used.
9. Facile preparation of continuous indium metal-organic framework thin films on indium tin oxide glass
International Nuclear Information System (INIS)
Continuous indium metal-organic framework thin films of In12O(OH)12[(OH)4·(H2O)5)][BTC]6 (MIL-96(In)) (BTC = 1,3,5-benzenetricarboxylate) were prepared on indium tin oxide glass by in situ solvothermal growth method. The structure of the films was confirmed by X-ray diffraction. The growth process and the possible growth mechanism of MIL-96(In) films were investigated by a scanning electron microscopy. Furthermore, the influence of the reaction conditions on the morphology and thickness of films was studied. The best crack-free, continuous film with thickness of approximate 6 μm was obtained at the proper concentrations of InCl3 and H3BTC of 25.0 mmol·l−1 at 100 °C for 12 h. - Highlights: • Continuous indium metal-organic framework thin films are prepared. • The growth process and the possible growth mechanism of thin films are investigated. • Indium tin oxide glass promotes the homogeneous nucleation of thin films
10. Ordered organic thin films self-assembled from the vapor phase
Science.gov (United States)
Debe, M. K.
1993-01-01
Organic films self-assembled from a liquid phase, as in Langmuir-Blodgett or adsorption from solution, have received much attention in the past decade as techniques to achieve highly oriented-ordered polymeric thin films. Many organic compounds including some of the same fatty acids have been vapor deposited as well. However, organic pigments and dyes comprise a major class of important materials which have very low solubilities yet excellent thermal stabilities, making them ideally suited for film deposition from the vapor phase. Surprisingly, such molecular systems exhibit a significant propensity to self order, a high sensitivity to deposition parameters, and a range of microstructural forms that cannot be duplicated by the less energetic mechanisms associated with solution adsorption processes. Molecular solids such as heterocyclic polynuclear aromatics are excellent candidates for film formation by vacuum deposition means. Over the past decade, our work and that of others investigating a wide variety of perylene and phthalocyanine derivatives identified five deposition parameters that can significantly affect film morphology, physical microstructure, and type and extent of ordering developed in vacuum and vapor transport grown films. These parameters are substrate temperature, deposition rate, substrate chemistry and epitaxy, ambient gas convective flows, and post deposition annealing. Examples of how each of these conditions manifest themselves in the film structure and ordering, most frequently revealed by scanning electron microscopy, reflection absorption infrared spectroscopy (RAIR), and grazing incidence x-ray diffraction (GIX), are presented.
11. VERUCLAY – a new type of photo-adsorbent active in the visible light range: modification of montmorillonite surface with organic surfactant
Science.gov (United States)
Montmorillonite K10 was treated with VeruSOL-3, a biodegradable and food-grade surfactant mixture of coconut oil, castor oil and citrus extracts, to manufacture a benign catalytic adsorbent that is active in the visible light. Veruclay was characterized by SEM, XRD, TGA, UVDRS, a...
12. Batch Scale Removal of an Organic Pollutant Amaranth Dye from Aqueous Solution using Pisum sativum Peels and Arachis hypogaea Shells as Adsorbents
International Nuclear Information System (INIS)
The goal of this study was to utilize low cost and environmentally friendly adsorbents for batch scale removal of Amaranth dye from aqueous medium. Peels of Pisum sativum (Pea) and Arachis hypogaea (Peanut) were utilized to investigate their dye removing capacity. The optimized adsorption conditions for Pisum sativum (P.S.P) and Arachis hypogaea (A.H.S) were: adsorbent dose; 0.6 and 0.4 g, contact time; 45 and 10 minutes, pH; 2.0 for both, agitation speed; 150 and 100 rpm and temperature; 60 and 50 degree C for P.S.P and A.H.S respectively. The adsorption data well suited to Langmuir isotherm. Maximum adsorption capacities were found to be 144.93 and 10.53 mg/g for P.S.P and A.H.S respectively. Feasibility of the process was indicated by negative values of thermodynamic parameters delta G/sup 0/ for both adsorbents. Kinetic studies indicated that adsorption of Amaranth dye from aqueous medium by Pisum sativum peels and Arachis hypogaea shells followed pseudo-seconder order kinetics. It was concluded that Pisum sativum peels are more effective adsorbent for removal of Amaranth from aqueous solution as compared to Arachis hypogaea shells. (author)
13. Analysis of surface films on lithium in various organic electrolytes
Energy Technology Data Exchange (ETDEWEB)
Kominato, A.; Yasukawa, E.; Sato, N.; Ijuuin, T.; Asahina, H.; Mori, S. [Mitsubishi Chemical Corp., Ibaraki (Japan). Tsukuba Research Center
1997-10-01
The surface films formed on lithium metal in ethylene carbonate (EC)+dimethyl carbonate (DMC) containing LiPF{sub 6}, LiClO{sub 4} and LiN(SO{sub 2}CF{sub 3}){sub 2} electrolytes were analysed by using Auger electron spectroscopy (AES), temperature-programmed decomposition mass spectrography (TPD-MS), FT-IR, ion chromatography (IC) and atomic adsorption spectroscopy (AAS). The morphology of the film was observed by using scanning electron microscopy (SEM). The film formed in the LiPF{sub 6} solution exhibited spherical morphology and was found to contain LiF, lithium oxide compounds (most of which seems to be inorganic), (CH{sub 2}OCO{sub 2}Li){sub 2} and CH{sub 3}OCO{sub 2}Li. The films in LiClO{sub 4} and LiN(SO{sub 2}CF{sub 3}){sub 2} were dendritic and contained the lithium oxide compounds, (CH{sub 2}OCO{sub 2}Li){sub 2} and CH{sub 3}OCO{sub 2}Li. (orig.)
14. Poly(methyl methacrylate) films for organic vapour sensing
CERN Document Server
Capan, R; Hassan, A K; Tanrisever, T
2003-01-01
Optical constants and fabrication parameters are investigated using surface plasmon resonance (SPR) studies on spun films of poly(methyl methacrylate) (PMMA) derivatives in contact with two different dielectric media. A value of 1.503 for the refractive index of PMMA films produced from a solution having concentration of 1 mg ml sup - sup 1 at the speed of 3000 rpm is in close agreement with the data obtained from ellipsometric measurements. The film thickness shows a power-law dependence on the spin speed but the thickness increases almost linearly with the concentration of the spreading solution. These results are in good agreement with the hydrodynamic theory for a low-viscosity and highly volatile liquid. On the basis of SPR measurements under dynamic conditions, room temperature response of PMMA films to benzene vapours is found to be fast, highly sensitive and reversible. The sensitivity of detection of toluene, ethyl benzene and m-xylene is much smaller than that of benzene.
15. Exciton-polaron quenching in organic thin-film transistors studied by fluorescence lifetime imaging microscopy
DEFF Research Database (Denmark)
Jensen, Per Baunegaard With; Leißner, Till; Osadnik, Andreas;
Organic semiconductors show great potential in electronic and optical applications. However, a major challenge is the degradation of the semiconductor materials that cause a reduction in device performance. Here, we present our investigations of Organic Thin Film Transistors (OTFT) based on the...
16. Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications
Indian Academy of Sciences (India)
S Philip Anthony; Shatabdi Porel; D Narayana Rao; T P Radhakrishnan
2005-11-01
Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which form perfectly polar assemblies in their crystalline state are found to organize as uniaxially oriented crystallites in vapor deposited thin films on glass substrate. Optical second harmonic generation from these films is investigated. A simple protocol is developed for the in-situ fabrication of highly monodisperse silver nanoparticles in a polymer film matrix. The methodology can be used to produce free-standing films. Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated.
17. Nucleation and strain-stabilization during organic semiconductor thin film deposition.
Science.gov (United States)
Li, Yang; Wan, Jing; Smilgies, Detlef-M; Bouffard, Nicole; Sun, Richard; Headrick, Randall L
2016-01-01
The nucleation mechanisms during solution deposition of organic semiconductor thin films determine the grain morphology and may influence the crystalline packing in some cases. Here, in-situ optical spectromicroscopy in reflection mode is used to study the growth mechanisms and thermal stability of 6,13-bis(trisopropylsilylethynyl)-pentacene thin films. The results show that the films form in a supersaturated state before transforming to a solid film. Molecular aggregates corresponding to subcritical nuclei in the crystallization process are inferred from optical spectroscopy measurements of the supersaturated region. Strain-free solid films exhibit a temperature-dependent blue shift of optical absorption peaks due to a continuous thermally driven change of the crystalline packing. As crystalline films are cooled to ambient temperature they become strained although cracking of thicker films is observed, which allows the strain to partially relax. Below a critical thickness, cracking is not observed and grazing incidence X-ray diffraction measurements confirm that the thinnest films are constrained to the lattice constants corresponding to the temperature at which they were deposited. Optical spectroscopy results show that the transition temperature between Form I (room temperature phase) and Form II (high temperature phase) depends on the film thickness, and that Form I can also be strain-stabilized up to 135 °C. PMID:27600905
18. Biological activities of organic compounds adsorbed onto ambient air particles: comparison between the cities of Teplice and Prague during the summer and winter seasons 2000-2001
Energy Technology Data Exchange (ETDEWEB)
Binkova, Blanka; Cerna, Milena; Pastorkova, Anna; Jelinek, Richard; Benes, Ivan; Novak, Jiri; Sram, Radim J
2003-04-09
The capital of the Czech Republic, Prague, appears today to be one of the most polluted residential areas in the country, whereas air pollution in the Northern Bohemia region (the former 'Black Triangle Region') has substantially decreased during the last decade, especially with respect to the gaseous pollutant SO{sub 2}. This study evaluated the biological activities of complex mixtures of organic compounds adsorbed onto ambient air particles (PM10) collected during the summer and winter seasons of 2000-2001 at three monitoring sites - Teplice (TP), Prague-Smichov (PRG-SM) (city centre) and Prague-Libus (PRG-LB) (suburban area). The following short-term in vitro assays with strikingly different endpoints were used: a bacterial mutagenicity test using the Salmonella typhimurium tester strain TA98 and YG1041, an acellular assay (CT DNA) combined with {sup 32}P-postlabelling to evaluate DNA adduct-forming potency and the chick embryotoxicity screening test (CHEST). The results of the mutagenicity test with the YG1041 strain, the acellular genotoxicity (DNA adducts) and the embryotoxicity tests responded to the amount of eight carcinogenic polycyclic aromatic hydrocarbons (PAHs) analysed in the EOM (dichloromethane extractable organic matter) samples tested. Nevertheless, the biological effects of the EOM did not differ between locations. The highest biological activity of the ambient air in terms of organic compounds associated with particles (per unit volume of air) was seen in the Prague city centre during both summer and winter seasons. At this location, B[a]P concentration ranged from 0.1 to 8.9 ng/m{sup 3} (mean 0.3 and 3.6 ng/m{sup 3} for summer and winter seasons, respectively), 13 PAHs ranged from 11 to 343 ng/m{sup 3} (mean 52 and 160 ng/m{sup 3} for summer and winter seasons, respectively). Generally, using in vitro tests, higher ambient air activity was found in the winter season as compared with the summer season at all three monitoring sites
19. Organic thin film transistor integration a hybrid approach
CERN Document Server
Li, Flora; Wu, Yiliang; Ong, Beng S
2013-01-01
Research on organic electronics (or plastic electronics) is driven by the need to create systems that are lightweight, unbreakable, and mechanically flexible. With the remarkable improvement in the performance of organic semiconductor materials during the past few decades, organic electronics appeal to innovative, practical, and broad-impact applications requiring large-area coverage, mechanical flexibility, low-temperature processing, and low cost. Thus, organic electronics appeal to a broad range of electronic devices and products including transistors, diodes, sensors, solar cells, lighting
20. Comparison of physicomechanical properties of films prepared from organic solutions and aqueous dispersion of Eudragit RL
Directory of Open Access Journals (Sweden)
H Afrasiabi Garekani
2011-05-01
Full Text Available Background and the purpose of the study: Mechanical properties of films prepared from aqueous dispersion and organic solutions of Eudragit RL were assessed and the effects of plasticizer type, concentration and curing were examined. Methods: Films were prepared from aqueous dispersion and solutions of Eudragit RL (isopropyl alcohol-water 9:1 containing 0, 10 or 20% (based on polymer weight of PEG 400 or Triethyl Citrate (TEC as plasticizer using casting method. Samples of films were stored in oven at 60ºC for 24 hrs (Cured. The stress-strain curve was obtained for each film using material testing machine and tensile strength, elastic modulus, %elongation and work of failure were calculated. Results and major conclusion: The films with no plasticizer showed different mechanical properties depending on the vehicle used. Addition of 10% or 20% of plasticizer decreased the tensile strength and elastic modulus and increased %elongation and work of failure for all films. The effect of PEG400 on mechanical properties of Eudragit RL films was more pronounced. The differences in mechanical properties of the films due to vehicle decreased by addition of plasticizer and increase in its concentration. Curing process weakened the mechanical properties of the films with no plasticizer and for films with 10% plasticizer no considerable difference in mechanical properties was observed before and after curing. For those with 20% plasticizer only films prepared from aqueous dispersion showed remarkable difference in mechanical properties before and after curing. Results of this study suggest that the mechanical properties of the Eudragit RL films were affected by the vehicle, type of plasticizer and its concentration in the coating liquid.
1. Surface-enhanced fluorescence and surface-enhanced Raman scattering of ultrathin layers of bichromophoric antenna systems adsorbed on silver nanoisland films
International Nuclear Information System (INIS)
We investigated a novel bichromophoric antenna system, characterized by energy transfer between a naphthalene group acting as the donor and a benzofurazane group acting as the acceptor. We studied the spectroscopic properties (infrared, Raman, UV-vis and fluorescence) of self-assembled monolayers of this molecular antenna on Ag nanoisland films and the energy-transfer process upon irradiation at 300 nm.
2. Indium-Doped Zinc Oxide Thin Films as Effective Anodes of Organic Photovoltaic Devices
Directory of Open Access Journals (Sweden)
Ziyang Hu
2011-01-01
Full Text Available Indium-doped zinc oxide (IZO thin films were prepared by low-cost ultrasonic spray pyrolysis (USP. Both a low resistivity (3.13×10−3 Ω cm and an average direct transmittance (400∼1500 nm about 80% of the IZO films were achieved. The IZO films were investigated as anodes in bulk-heterojunction organic photovoltaic (OPV devices based on poly(3-hexylthiophene and [6,6]-phenyl C61-butyric acid methyl ester. The device fabricated on IZO film-coated glass substrate showed an open circuit voltage of 0.56 V, a short circuit current of 8.49 mA cm-2, a fill factor of 0.40, and a power conversion efficiency of 1.91%, demonstrating that the IZO films prepared by USP technique are promising low In content and transparent electrode candidates of low-cost OPV devices.
3. Flexible barrier film, method of forming same, and organic electronic device including same
Energy Technology Data Exchange (ETDEWEB)
Blizzard, John; Tonge, James Steven; Weidner, William Kenneth
2013-03-26
A flexible barrier film has a thickness of from greater than zero to less than 5,000 nanometers and a water vapor transmission rate of no more than 1.times.10.sup.-2 g/m.sup.2/day at 22.degree. C. and 47% relative humidity. The flexible barrier film is formed from a composition, which comprises a multi-functional acrylate. The composition further comprises the reaction product of an alkoxy-functional organometallic compound and an alkoxy-functional organosilicon compound. A method of forming the flexible barrier film includes the steps of disposing the composition on a substrate and curing the composition to form the flexible barrier film. The flexible barrier film may be utilized in organic electronic devices.
4. Simulation of heterojunction organic thin film devices and exciton diffusion analysis in stacked-hetero device
Science.gov (United States)
Kamohara, Itaru; Townsend, Mark; Cottle, Bob
2005-01-01
A two-dimensional device simulation methodology for organic heterojunction thin film devices has been developed. Multilayer organic light emitting diodes, organic thin film heterojunction field effect transistors, and stacked heterojunction organic complementary devices were simulated. Heterojunction organic layer devices have been analyzed using a two-dimensional simulator with heterointerface models and organic material specific models. The stacked heterojunction organic double carrier device exhibits both horizontal and vertical carrier flow in the organic thin film. This unique dual-directional carrier flow shows efficient electron-hole recombination resulting in exciton generation in the organic heterojunction layers. Furthermore, the enhanced behavior of the generated excitons has been analyzed using a self-consistent exciton diffusion model. The vertical (thickness) diffusion of the excitons and the lateral (along heterointerface) diffusion (accompanied by exciton hopping) were simulated. The exciton diffusion model is applicable to electroluminescent characteristics in organic devices. This feature is one of the essential differences between the present model for high-injected polymer devices and conventional drift-diffusion transport in nonpolymer semiconductor devices.
5. Fine structures of organic photovoltaic thin films probed by frequency-shift electrostatic force microscopy
Science.gov (United States)
Araki, Kento; Ie, Yutaka; Aso, Yoshio; Matsumoto, Takuya
2016-07-01
The localized charge and electrostatic properties of organic photovoltaic thin films are predominating factors for controlling energy conversion efficiency. The surface potential and electrostatic structures of organic photovoltaic thin films were investigated by frequency shift mode Kelvin force microscopy (KFM) and electrostatic force microscopy (EFM). The KFM images of a poly[2-methoxy-5-(3‧,7‧-dimethyloctyloxy)-1,4-phenylene vinylene]/phenyl-C61-butyric-acid-methyl ester (PCBM) blend thin film reveals that the PCBM domains precipitate as the topmost layer on the thin films. We find fine structures that were not observed in the topography and KFM images. The bias dependence of the EFM images suggests that the EFM contrast reflects the field-induced polarization, indicating the presence of charge trapping sites.
6. Tetracene films for light-emitting transistors: chemical and physical effects of the organic dielectric substrates
Science.gov (United States)
Santato, Clara; Cicoira, Fabio; Bertolazzi, Simone
2010-03-01
Tetracene vacuum-sublimed films have been used to demonstrate the first Organic Light Emitting Field Effect Transistor (OLEFET), in 2003. Because of their planar configuration, OLEFET are excellent systems to study fundamental processes such as charge injection, transport, and light emission in organic semiconductor films. OLEFET are intensively investigated for applications in active matrix full-color displays and, ultimately, lasers. Since the first Tetracene-OLEFET, a number of excellent studies have been reported on vacuum-sublimed as well as solution-processed films of organic semiconductors incorporated into OLEFET. Investigating the role played by the surface substrate chemistry and establishing sound structure-property relationships in organic semiconductor films incorporated into OLEFET structures are the keys to understand and improve the optoelectronic characteristics of OLEFET. Here we present our results on the morphological, structural, light-emission, and charge transport properties in field-effect transistor configuration of vacuum-sublimed tetracene films deposited on chemically and physically different organic dielectric substrates (HMDS- and OTS-treated SiO2, polystyrene, parylene, PMMA).
7. Corrosion protection by sonoelectrodeposited organic films on zinc coated steel.
Science.gov (United States)
Et Taouil, Abdeslam; Mahmoud, Mahmoud Mourad; Lallemand, Fabrice; Lallemand, Séverine; Gigandet, Marie-Pierre; Hihn, Jean-Yves
2012-11-01
A variety of coatings based on electrosynthesized polypyrrole were deposited on zinc coated steel in presence or absence of ultrasound, and studied in terms of corrosion protection. Cr III and Cr VI commercial passivation were used as references. Depth profiling showed a homogeneous deposit for Cr III, while SEM imaging revealed good surface homogeneity for Cr VI layers. These chromium-based passivations ensured good protection against corrosion. Polypyrrole (PPy) was also electrochemically deposited on zinc coated steel with and without high frequency ultrasound irradiation in aqueous sodium tartrate-molybdate solution. Such PPy coatings act as a physical barrier against corrosive species. PPy electrosynthesized in silent conditions exhibits similar properties to Cr VI passivation with respect to corrosion protection. Ultrasound leads to more compact and more homogeneous surface structures for PPy, as well as to more homogeneous distribution of doping molybdate anions within the film. Far better corrosion protection is exhibited for such sonicated films. PMID:22516111
8. Implantation and annealing effects in molecular organic films
CERN Document Server
Pakhomov, G L; Shashkin, V I; Tura, J M; Ribo, J M; Ottaviano, L
2002-01-01
Ion implantation and annealing effects on the surface of phthalocyanine thin films have been studied by means of atomic force microscopy and electron spectroscopy for chemical analysis. Both the topology and the chemical composition of the surface are affected by irradiation. The influence of the irradiation dose is shown. The chemical degradation of the layer results mainly in the decrease of atomic concentration of nitrogen and chlorine, and in the increase of atomic concentration of oxygen. At highest dose, carbonization becomes important. Furthermore, N 1s, C 1s and Cl 2p core levels testify that the formation of new chemical species occurs in implanted pthalocyanine films. All these processes are modified by subsequent heat treatment in different ways, depending on the applied implantation fluence.
9. A Naphthalenediimide-Based Metal-Organic Framework and Thin Film Exhibiting Photochromic and Electrochromic Properties.
Science.gov (United States)
Xie, Yi-Xin; Zhao, Wen-Na; Li, Guo-Chang; Liu, Peng-Fei; Han, Lei
2016-01-19
A multifunctional metal-organic framework, NBU-3, has been explored as a 2D three-connected network based on a naphthalenediimide-based ligand. The NBU-3 crystals display photochromic properties, and NBU-3 thin films on FTO substrates exhibit electrochromic properties. NBU-3 is the first example of MOF materials containing both photochromic and electrochromic properties, which can be desirable for thin film devices. PMID:26713454
10. Nanostructuring on zinc phthalocyanine thin films for single-junction organic solar cells
Science.gov (United States)
Chaudhary, Dhirendra K.; Kumar, Lokendra
2016-05-01
Vertically aligned and random oriented crystalline molecular nanorods of organic semiconducting Zinc Phthalocyanine (ZnPc) have been grown on ITO coated glass substrate using solvent volatilization method. Interesting changes in surface morphology were observed under different solvent treatment. Vertically aligned nanorods of ZnPc thin film were observed in the films treated with acetone, where as the random oriented nanorods were observed in the films treated with chloroform. The X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) have been used for characterization of nanostructures. The optical properties of the nanorods have been investigated by UV-Vis. absorption spectroscopy.
11. Wrinkling of YBa2Cu3O7-x film prepared by trifluoroacetate metal organic deposition
Science.gov (United States)
Jin, L. H.; Li, C. S.; Yu, Z. M.; Feng, J. Q.; Zhang, S. N.; Sulpice, A.; Wang, Y.; Zhang, P. X.
2015-11-01
YBa2Cu3O7-x (YBCO) films with wrinkles have been fabricated on LaAlO3(1 0 0) substrates by trifluoroacetate metal organic deposition (TFA-MOD). The decomposition behavior of YBCO-TFA gel and the formation mechanism of wrinkles were analyzed by thermal analysis, Fourier transform infrared spectroscopy, and atomic force microscopy. The effects of wrinkles on the texture, microstructure and critical current density of the final crystallized film were also investigated by X-ray diffraction and scanning electron microscopy. The heating rate in the decomposition process was a crucial parameter to control the wavelength and wave amplitude of wrinkles on the surface of YBCO precursor film. Furthermore, the wrinkles of precursor films were transformed into the ridges of crystallized films during the crystallization process. Large ridges resulted in the degradation of texture of YBCO crystallized films. The decrease of critical current density (Jc) of YBCO crystallized films could be ascribed to the formation of ridges, the segregated phases and the degradation of texture. It suggested that the smooth morphology of YBCO precursor films would be beneficial to the enhancement of Jc value.
12. Solution-Processed Organic Thin-Film Transistor Array for Active-Matrix Organic Light-Emitting Diode
Science.gov (United States)
Harada, Chihiro; Hata, Takuya; Chuman, Takashi; Ishizuka, Shinichi; Yoshizawa, Atsushi
2013-05-01
We developed a 3-in. organic thin-film transistor (OTFT) array with an ink-jetted organic semiconductor. All layers except electrodes were fabricated by solution processes. The OTFT performed well without hysteresis, and the field-effect mobility in the saturation region was 0.45 cm2 V-1 s-1, the threshold voltage was 3.3 V, and the on/off current ratio was more than 106. We demonstrated a 3-in. active-matrix organic light-emitting diode (AMOLED) display driven by the OTFT array. The display could provide clear moving images. The peak luminance of the display was 170 cd/m2.
13. Molecular Dynamics Study of Ionic Liquid Film Based on [emim][Tf2N] and [emim][TfO] Adsorbed on Highly Oriented Pyrolytic Graphite
Institute of Scientific and Technical Information of China (English)
XUE Xiang-gui; ZHAO Li; L(U) Zhong-yuan; QIAN Hu-iun
2013-01-01
Molecular dynamics simulation was used to study the ionic liquid(IL) crystalline film based on 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide([emim][Tf2N]) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate([emim][TfO]) on the graphite surface.Our results show that the cations are parallelly dis-tributed to the surface in the l/2 monolayer(ML) crystalline film.The [Tf2N] anions are parallel to the surface with the oxygen atoms at the bottom,whereas the [TfO] anions are perpendicularly distributed to the surface also with the oxygen atoms at the bottom in the 1/2 ML crystalline film.It has been found that the IL-vapor interface strongly influences the arrangement of ions at the interface.The anions in the top layer with the oxygen atoms outmost turn over to make themselves with the F atoms outmost so as to form C-H...O hydrogen bonds with the cations.The calculated orientational ordering shows that in the outmost layer at the IL-vapor interface,the cation rings present either parallel or perpendicular to the surface at 350 K.
14. Singlet Exciton Lifetimes in Conjugated Polymer Films for Organic Solar Cells
Directory of Open Access Journals (Sweden)
Stoichko D. Dimitrov
2016-01-01
Full Text Available The lifetime of singlet excitons in conjugated polymer films is a key factor taken into account during organic solar cell device optimization. It determines the singlet exciton diffusion lengths in polymer films and has a direct impact on the photocurrent generation by organic solar cell devices. However, very little is known about the material properties controlling the lifetimes of singlet excitons, with most of our knowledge originating from studies of small organic molecules. Herein, we provide a brief summary of the nature of the excited states in conjugated polymer films and then present an analysis of the singlet exciton lifetimes of 16 semiconducting polymers. The exciton lifetimes of seven of the studied polymers were measured using ultrafast transient absorption spectroscopy and compared to the lifetimes of seven of the most common photoactive polymers found in the literature. A plot of the logarithm of the rate of exciton decay vs. the polymer optical bandgap reveals a medium correlation between lifetime and bandgap, thus suggesting that the Energy Gap Law may be valid for these systems. This therefore suggests that small bandgap polymers can suffer from short exciton lifetimes, which may limit their performance in organic solar cell devices. In addition, the impact of film crystallinity on the exciton lifetime was assessed for a small bandgap diketopyrrolopyrrole co-polymer. It is observed that the increase of polymer film crystallinity leads to reduction in exciton lifetime and optical bandgap again in agreement with the Energy Gap Law.
15. Singlet Exciton Lifetimes in Conjugated Polymer Films for Organic Solar Cells
KAUST Repository
Dimitrov, Stoichko
2016-01-13
The lifetime of singlet excitons in conjugated polymer films is a key factor taken into account during organic solar cell device optimization. It determines the singlet exciton diffusion lengths in polymer films and has a direct impact on the photocurrent generation by organic solar cell devices. However, very little is known about the material properties controlling the lifetimes of singlet excitons, with most of our knowledge originating from studies of small organic molecules. Herein, we provide a brief summary of the nature of the excited states in conjugated polymer films and then present an analysis of the singlet exciton lifetimes of 16 semiconducting polymers. The exciton lifetimes of seven of the studied polymers were measured using ultrafast transient absorption spectroscopy and compared to the lifetimes of seven of the most common photoactive polymers found in the literature. A plot of the logarithm of the rate of exciton decay vs. the polymer optical bandgap reveals a medium correlation between lifetime and bandgap, thus suggesting that the Energy Gap Law may be valid for these systems. This therefore suggests that small bandgap polymers can suffer from short exciton lifetimes, which may limit their performance in organic solar cell devices. In addition, the impact of film crystallinity on the exciton lifetime was assessed for a small bandgap diketopyrrolopyrrole co-polymer. It is observed that the increase of polymer film crystallinity leads to reduction in exciton lifetime and optical bandgap again in agreement with the Energy Gap Law.
16. Wavelength Dispersive X-ray Fluorescence Spectrometry for the Analysis of Organic Polymer Film
International Nuclear Information System (INIS)
Recently, many studies have been focused on the thin films because there are numerous industrial processes relevant to thin films such as fuel cells, sensors, lubricants, coatings, and so on. Physical and chemical properties of solid surface have been modified by ultra-thin coatings such as Langmuir-Blodgett (LB) method with a variety of types of organic functional materials for the specific purposes in many applications. In addition, the layer-by-layer technique using polyelectrolyte films are now of interest as biosensors, electrochromic and electroluminescent devices, etc. In general, several methods such as X-ray or neutron reflectivity, and quartz crystal microbalance (QCM) have been utilized for the thin film analysis. These optical techniques can measure the film thicknesses up to hundreds of nanometers while X-ray photoelectron spectroscopy is widely used to study a few nanometers thick films. Other methods such as X-ray Photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atom force microscopy (AFM) have also been used in the film analysis in spite of some disadvantages for each method. X-ray fluorescence (XRF) has long been used as a rapid and simple analytical tool for the analysis of elemental composition of materials. XRF technique is suitable for on-line or in-line real-time monitoring because it is a non-destructive and rapid analysis with good precision and good accuracy at low cost. The aim of this work is to develop a new analytical technique for the quantitative analysis of polymer film on metal substrate. In the present study, Compton peak profile was investigated under different experimental conditions by using wavelength-dispersive XRF (WD-XRF). Compared to energy-dispersive XRF (ED-XRF), WD-XRF is more adequate in an accurate quantitative analysis of thin organic film
17. How long may a breath sample be stored for at -80 °C? A study of the stability of volatile organic compounds trapped onto a mixed Tenax:Carbograph trap adsorbent bed from exhaled breath.
Science.gov (United States)
Kang, S; Paul Thomas, C L
2016-01-01
Thermal desorption is used extensively in exhaled breath volatile organic compound (VOC) analysis, and it is often necessary to store the adsorbent tube samples before analysis. The possible introduction of storage artefacts is an important potential confounding factor in the development of standard methodologies for breath sampling and analysis. The stability of VOCs trapped from breath samples onto a dual bed Tenax(®) TA:Carbograph adsorbent tube and stored -80°C was studied over 12.5 month. 25 samples were collected from a single male participant over 3 h and then stored at -80 °C. Randomly selected adsorbent tubes were subsequent analysed by thermal desorption-gas chromatography-mass spectrometry at 5 times points throughout the 12.5 month of the study. Toluene-d8, decane-d22 and hexadecane-d34 internal standards were used to manage the instrument variability throughout the duration of the study. A breath-matrix consisting of 161 endogenous and 423 exogenous VOC was created. Iterative orthogonal partial least squared discriminant analysis (OPLS-DA) and principal components analysis (PCA) indicated that it was not possible to detect storage artefacts at 1.5 month storage. By 6 month storage artefacts were discernible with significant changes observed for 27% of the recovered VOC. Endogenous VOC were observed to be more susceptible to storage. A paired two-tailed t-test on the endogenous compounds indicated that the maximum storage duration under these conditions was 1.5 month with 94% of the VOCs stable. This study indicates that a prudent approach is best adopted for the storage of adsorbent samples; storage times should be minimised, and storage time examined as a possible discriminatory factor in multivariate analysis. PMID:27272219
18. Molecular Adsorber Coating
Science.gov (United States)
Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory
2011-01-01
A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.
19. Controlled Microstructure and Photochromism of Inorganic-organic Thin Films by Ultrasound
Institute of Scientific and Technical Information of China (English)
2007-01-01
A series of inorganic-organic thin films based on uniformly dispersed nanoparticles of polyoxometalates (POM)entrapped in polyacrylamide (PAM) matrix were prepared by ultrasonic method with different irradiation time.The microstructure, photochromic behavior and mechanism of the films were studied by transmission electron microscopy (TEM), ultraviolet-visible spectra (UV-VIS) and Fourier transform-infrared spectroscopy (FT-IR).The microstructure and photochromic properties of the hybrid thin films could be controlled by ultrasound.TEM image revealed that the average size of phosphotungstic acid (PWA) nanoparticles decreased from 20 to 10 nm with the ultrasound irradiation time from 30 to 60 min. After irradiated with ultraviolet light,the transparent films changed from colorless to blue and showed reversible photochromism. The hybrid film, with ultrasound irradiation for 60 min had higher photochromic efficiency and faster bleaching reaction than the one with ultrasound irradiation for 30 min. FT-IR spectra showed that the Keggin geometry of heteropolyoxometalate was still preserved inside the composites, and the interactions between polyanions and polymer matrix increased as the ultrasound time prolonged. It is suggested that the mechanism of the different photochromic properties for the inorganic-organic thin films is the variation of the microstructure and interfacial interactions induced by ultrasound.
20. Optical properties of organic semiconductor thin films. Static spectra and real-time growth studies
Energy Technology Data Exchange (ETDEWEB)
Heinemeyer, Ute
2009-07-20
The aim of this work was to establish the anisotropic dielectric function of organic thin films on silicon covered with native oxide and to study their optical properties during film growth. While the work focuses mainly on the optical properties of Diindenoperylene (DIP) films, also the optical response of Pentacene (PEN) films during growth is studied for comparison. Spectroscopic ellipsometry and differential reflectance spectroscopy are used to determine the dielectric function of the films ex-situ and in-situ, i.e. in air and in ultrahigh vacuum. Additionally, Raman- and fluorescence spectroscopy is utilized to characterize the DIP films serving also as a basis for spatially resolved optical measurements beyond the diffraction limit. Furthermore, X-ray reflectometry and atomic force microscopy are used to determine important structural and morphological film properties. The absorption spectrum of DIP in solution serves as a monomer reference. The observed vibronic progression of the HOMO-LUMO transition allows the determination of the Huang-Rhys parameter experimentally, which is a measure of the electronic vibrational coupling. The corresponding breathing modes are measured by Raman spectroscopy. The optical properties of DIP films on native oxide show significant differences compared to the monomer spectrum due to intermolecular interactions. First of all, the thin film spectra are highly anisotropic due to the structural order of the films. Furthermore the Frenkel exciton transfer is studied and the energy difference between Frenkel and charge transfer excitons is determined. Real-time measurements reveal optical differences between interfacial or surface molecules and bulk molecules that play an important role for device applications. They are not only performed for DIP films but also for PEN films. While for DIP films on glass the appearance of a new mode is visible, the spectra of PEN show a pronounced energy red-shift during growth. It is shown how the
1. Thin aligned organic polymer films for liquid crystal devices
International Nuclear Information System (INIS)
This project was designed to investigate the possibility of producing alignment layers for liquid crystal devices by cross-linking thin films containing anisotropic polymer bound chromophores via irradiation with polarised ultraviolet light. Photocross-linkable polymers find use in microelectronics, liquid crystal displays, printing and UV curable lacquers and inks; so there is an increasing incentive for the development of new varieties of photopolymers in general. The synthesis and characterisation of two new photopolymers that are suitable as potential alignment layers for liquid crystal devices are reported in this thesis. The first polymer contains the anthracene chromophore attached via a spacer unit to a methacrylate backbone and the second used a similarly attached aryl azide group. Copolymers of the new monomers with methyl methacrylate were investigated to establish reactivity ratios in order to understand composition drift during polymerisation. (author)
2. Thin aligned organic polymer films for liquid crystal devices
CERN Document Server
Foster, K E
1997-01-01
This project was designed to investigate the possibility of producing alignment layers for liquid crystal devices by cross-linking thin films containing anisotropic polymer bound chromophores via irradiation with polarised ultraviolet light. Photocross-linkable polymers find use in microelectronics, liquid crystal displays, printing and UV curable lacquers and inks; so there is an increasing incentive for the development of new varieties of photopolymers in general. The synthesis and characterisation of two new photopolymers that are suitable as potential alignment layers for liquid crystal devices are reported in this thesis. The first polymer contains the anthracene chromophore attached via a spacer unit to a methacrylate backbone and the second used a similarly attached aryl azide group. Copolymers of the new monomers with methyl methacrylate were investigated to establish reactivity ratios in order to understand composition drift during polymerisation.
3. XANES analysis of tribochemical and thermal films generating from some organic polysulfides
Institute of Scientific and Technical Information of China (English)
YI Hongling; ZENG Xiangqiong; CAO Yan; REN Tianhui; M. Kasrai; G. M. Bancroft
2006-01-01
X-ray absorption near edge structure (XANES) spectroscopy has been firstly used to characterize the chemical nature of tribochemical and thermal films generated from alkyl, benzyl and acylcontaining organic polysulfides. It has been found that the thermal films generated from these polysulfides are mainly composed of FeSO4, and alkyl disulfides also exist in the subsurface and bulk of thermal films generated from acyl-containing polysulfides. Under tribochemical conditions, the composition of film is dependent on the molecular structure of the additives.Namely, the tribochemical film generated from alkyl polysulfide is composed of alkyl disulfide in the out surface, a mixture of FeSO4, FeS2 and sulfoxide in the subsurface, and FeSO4 in the bulk; the composition of the tribochemical film for benzyl polysulfide consists of FeSO4 in the out surface, while the composition in subsurface and bulk is the same as the alkyl polysulfide. For acyl-containing polysulfides, the tribochemical films consist of alkyl disulfide in the out surface, and FeS2 in the subsurface and bulk.
4. Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers
International Nuclear Information System (INIS)
Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method. Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (EITO ≈ 96.7 GPa, EHKUST−1 ≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered. Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices
5. Nanomechanical investigation of thin-film electroceramic/metal-organic framework multilayers
Energy Technology Data Exchange (ETDEWEB)
Best, James P., E-mail: [email protected], E-mail: [email protected], E-mail: [email protected]; Michler, Johann; Maeder, Xavier [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Liu, Jianxi; Wang, Zhengbang; Tsotsalas, Manuel; Liu, Jinxuan; Gliemann, Hartmut; Weidler, Peter G.; Redel, Engelbert, E-mail: [email protected], E-mail: [email protected], E-mail: [email protected]; Wöll, Christof, E-mail: [email protected], E-mail: [email protected], E-mail: [email protected] [Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Röse, Silvana [Preparative Macromolecular Chemistry, Institute for Chemical Technology and Polymer Chemistry (ICTP), Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76128 Karlsruhe (Germany); Institute for Biological Interfaces (IBG), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Oberst, Vanessa [Institute of Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Walheim, Stefan [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)
2015-09-07
Thin-film multilayer stacks of mechanically hard magnetron sputtered indium tin oxide (ITO) and mechanically soft highly porous surface anchored metal-organic framework (SURMOF) HKUST-1 were studied using nanoindentation. Crystalline, continuous, and monolithic surface anchored MOF thin films were fabricated using a liquid-phase epitaxial growth method. Control over respective fabrication processes allowed for tuning of the thickness of the thin film systems with a high degree of precision. It was found that the mechanical indentation of such thin films is significantly affected by the substrate properties; however, elastic parameters were able to be decoupled for constituent thin-film materials (E{sub ITO} ≈ 96.7 GPa, E{sub HKUST−1} ≈ 22.0 GPa). For indentation of multilayer stacks, it was found that as the layer thicknesses were increased, while holding the relative thickness of ITO and HKUST-1 constant, the resistance to deformation was significantly altered. Such an observation is likely due to small, albeit significant, changes in film texture, interfacial roughness, size effects, and controlling deformation mechanism as a result of increasing material deposition during processing. Such effects may have consequences regarding the rational mechanical design and utilization of MOF-based hybrid thin-film devices.
6. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices
Energy Technology Data Exchange (ETDEWEB)
Macedo, Andreia G. [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Grova, Isabel R.; Ackcelrud, Leni [Laboratorio de Polimeros Paulo Scarpa, Departamento de Quimica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Reis, Francoise T.; Sartorelli, Maria L. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Roman, Lucimara S., E-mail: [email protected] [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil)
2012-05-01
In this work, porous ordered TiO{sub 2} films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.
7. Ordered nanocolumn-array organic semiconductor thin films with controllable molecular orientation
Science.gov (United States)
Yang, Bingchu; Duan, Haichao; Zhou, Conghua; Gao, Yongli; Yang, Junliang
2013-12-01
Ordered nanocolumn-array phthalocynine semiconductor thin films with controllable molecular orientation were fabricated by combining molecular template growth (MTG) and glancing angle deposition (GLAD) techniques. The pre-deposited planar perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA) molecular template layer induces phthalocynine molecules arrange with a lying-down molecular orientation, in which the π-π stacking is vertical to the substrate improving the charge transport along the vertical direction; While the GLAD technique supports the formation of nanocolumn-array thin films, supplying a much larger exposed surface area than the conventional compact thin films. The ordered nanocolumn-array thin films with controllable molecular orientation fabricated by combining MTG and GLAD techniques show the potentials to fabricate ordered bulk heterojunction for improving the performance in organic photovoltaics.
8. Mapping chemical concentration in binary thin organic films via multi-wavelength scanning absorption microscopy (MWSAM)
International Nuclear Information System (INIS)
The composition and thickness of binary thin organic films is determined by measuring the optical absorption at multiple wavelengths across the film surface and performing a component analysis fit to absorption standards for the materials. The multiple laser wavelengths are focused onto the surface using microscope objectives and raster scanned across the film surface using a piezo-electric actuator X–Y stage. All of the wavelengths are scanned simultaneously with a frequency division multiplexing system used to separate the individual wavelength response. The composition values are in good quantitative agreement with measurements obtained by scanning transmission x-ray microscopy (STXM). This new characterization technique extends quantitative compositional mapping of thin films to thickness regimes beyond that accessible by STXM. (paper)
9. Tunable electrical conductivity in oriented thin films of tetrathiafulvalene-based covalent organic framework
Energy Technology Data Exchange (ETDEWEB)
Cai, SL; Zhang, YB; Pun, AB; He, B; Yang, JH; Toma, FM; Sharp, ID; Yaghi, OM; Fan, J; Zheng, SR; Zhang, WG; Liu, Y
2014-09-16
Despite the high charge-carrier mobility in covalent organic frameworks (COFs), the low intrinsic conductivity and poor solution processability still impose a great challenge for their applications in flexible electronics. We report the growth of oriented thin films of a tetrathiafulvalene-based COF (TTF-COF) and its tunable doping. The porous structure of the crystalline TTF-COF thin film allows the diffusion of dopants such as I-2 and tetracyanoquinodimethane (TCNQ) for redox reactions, while the closely packed 2D grid sheets facilitate the cross-layer delocalization of thus-formed TTF radical cations to generate more conductive mixed-valence TTF species, as is verified by UV-vis-NIR and electron paramagnetic resonance spectra. Conductivity as high as 0.28 S m(-1) is observed for the doped COF thin films, which is three orders of magnitude higher than that of the pristine film and is among the highest for COF materials.
10. Layer-by-layer deposited organic/inorganic hybrid multilayer films containing noncentrosymmetrically orientated azobenzene chromophores.
Science.gov (United States)
Kang, En-Hua; Bu, Tianjia; Jin, Pengcheng; Sun, Junqi; Yang, Yanqiang; Shen, Jiacong
2007-07-01
Organic/inorganic hybrid multilayer films with noncentrosymmetrically orientated azobenzene chromophores were fabricated by the sequential deposition of ZrO2 layers by a surface sol-gel process and subsequent layer-by-layer (LbL) adsorption of the nonlinear optical (NLO)-active azobenzene-containing polyanion PAC-azoBNS and poly(diallyldimethylammonium chloride) (PDDA). Noncentrosymmetric orientation of the NLO-active azobenzene chromophores was achieved because of the strong repulsion between the negatively charged ZrO(2) and the sulfonate groups of the azobenzene chromophore in PAC-azoBNS. Regular deposition of ZrO(2)/PAC-azoBNS/PDDA multilayer films was verified by UV-vis absorption spectroscopy and quartz crystal microbalance measurements. Both UV-vis absorption spectroscopy and transmission second harmonic generation (SHG) measurements confirmed the noncentrosymmetric orientation of the azobenzene chromophores in the as-prepared ZrO2/PAC-azoBNS/PDDA multilayer films. The square root of the SHG signal (I(2omega)(1/2)) increases with the increase of the azobenzene graft ratio in PAC-azoBNS as the number of deposition cycles of the ZrO(2)/PAC-azoBNS/PDDA films remains the same, while the second-order susceptibility chi(zzz)(2) of the film decreases with the increase of the azobenzene graft ratio. Furthermore, the present method was successfully extended to realize the noncentrosymmetric orientation of azobenzene chromophores in multilayer films when small organic azobenzene compounds with carboxylic acid and/or hydroxyl groups at one end and sulfonate groups at the other end were used. The present method was characterized by its simplicity and flexibility in film preparation, and it is anticipated to be a facile way to fabricate second-order nonlinear optical film materials. PMID:17555337
11. Film-coupled nanoparticles by atomic layer deposition: Comparison with organic spacing layers
Energy Technology Data Exchange (ETDEWEB)
Ciracì, Cristian, E-mail: [email protected]; Mock, Jack J.; McGuire, Felicia; Liu, Xiaojun; Smith, David R. [Center for Metamaterials and Integrated Plasmonics and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Chen, Xiaoshu; Oh, Sang-Hyun [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)
2014-01-13
Film-coupled nanoparticle systems have proven a reliable platform for exploring the field enhancement associated with sub-nanometer sized gaps between plasmonic nanostructures. In this Letter, we present a side-by-side comparison of the spectral properties of film-coupled plasmon-resonant, gold nanoparticles, with dielectric spacer layers fabricated either using atomic layer deposition or using organic layers (polyelectrolytes or self-assembled monolayers of molecules). In either case, large area, uniform spacer layers with sub-nanometer thicknesses can be accurately deposited, allowing extreme coupling regimes to be probed. The observed spectral shifts of the nanoparticles as a function of spacer layer thickness are similar for the organic and inorganic films and are consistent with numerical calculations taking into account the nonlocal response of the metal.
12. V2O5 thin film deposition for application in organic solar cells
Science.gov (United States)
Arbab, Elhadi A. A.; Mola, Genene Tessema
2016-04-01
Vanadium pentoxide V2O5 films were fabricated by way of electrochemical deposition technique for application as hole transport buffer layer in organic solar cell. A thin and uniform V2O5 films were successfully deposited on indium tin oxide-coated glass substrate. The characterization of surface morphology and optical properties of the deposition suggest that the films are suitable for photovoltaic application. Organic solar cell fabricated using V2O5 as hole transport buffer layer showed better devices performance and environmental stability than those devices fabricated with PEDOT:PSS. In an ambient device preparation condition, the power conversion efficiency increases by nearly 80 % compared with PEDOT:PSS-based devices. The devices lifetime using V2O5 buffer layer has improved by a factor of 10 over those devices with PEDOT:PSS.
13. Metallo-organic decomposition for superconductive YBa2Cu3O7-x film
International Nuclear Information System (INIS)
Polycrystalline Y-Ba-Cu-O thin films have been deposited on alumina and sapphire substrates by using a metallo-organic decomposition method. The metallo-organic precursors of yttrium, barium, and copper metal-carboxylates have been synthesized and dissolved in a common solvent to make the ink. Deposition of the ink was made by a multi-layer spin-on coating followed by a thermal treatment. The treated films were polycrystalline, and the electrical results showed an onset temperature of about 90 K and a zero resistance temperature of 75 K. A mechanism has been postulated for the thermal decomposition of the compounds to the superconductive film. The principle of thermodynamics on this method is discussed
14. Maximum probing depth of low-energy photoelectrons in an amorphous organic semiconductor film
Energy Technology Data Exchange (ETDEWEB)
Ozawa, Yusuke [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Nakayama, Yasuo, E-mail: [email protected] [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Machida, Shin’ichi; Kinjo, Hiroumi [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Ishii, Hisao [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Center for Frontier Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)
2014-12-15
Highlights: • Photoelectron attenuation lengths (AL) through amorphous organic films were examined. • In the energy range below 9 eV, AL fluctuates unlike a prediction by universal curve. • AL of photoelectron yield spectroscopy (PYS) measurements was found to be ∼3.6 nm. • PYS signals still survived through an 18 nm-thick film despite such a moderate AL. • This indicates buried interfaces in practical organic devices can be accessed by PYS. - Abstract: The attenuation length (AL) of low energy photoelectrons inside a thin film of a π-conjugated organic semiconductor material, 2,2′,2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole), was investigated using ultraviolet photoelectron spectroscopy (UPS) and photoelectron yield spectroscopy (PYS) to discuss their probing depth in amorphous organic thin films. The present UPS results indicated that the AL is 2–3 nm in the electron energy range of 6.3–8.3 eV with respect to the Fermi level, while the PYS measurements which collected the excited electrons in a range of 4.5–6 eV exhibited a longer AL of 3.6 nm. Despite this still short AL in comparison to a typical thickness range of electronic devices that are a few tens of nm-thick, the photoemission signal penetrating through further thicker (18 nm) organic film was successfully detected by PYS. This fact suggests that the electronic structures of “buried interfaces” inside practical organic devices are accessible using this rather simple measurement technique.
15. Strongly Dichroic Organic Films via Controlled Assembly of Modular Aromatic Charge-Transfer Liquid Crystals.
Science.gov (United States)
Bé, Ariana Gray; Tran, Cheryl; Sechrist, Riley; Reczek, Joseph J
2015-10-01
The formation of highly anisotropic organic thin films based on the designed self-assembly of mixed-stack liquid crystals is reported. A series of alkoxyanthracene donors is combined in a modular fashion with a naphthalenediimide acceptor to generate new charge-transfer columnar liquid crystals. Materials characterization and molecular modeling provides insight into structure-function relationships in these organic materials that lead to the striking bulk dichroic properties of certain molecular assemblies. PMID:26375256
16. Organic donor-acceptor thin film systems. Towards optimized growth conditions
Energy Technology Data Exchange (ETDEWEB)
Keller, Kerstin Andrea
2009-06-30
In this work the preparation of organic donor-acceptor thin films was studied. A chamber for organic molecular beam deposition was designed and integrated into an existing deposition system for metallic thin films. Furthermore, the deposition system was extended by a load-lock with integrated bake-out function, a chamber for the deposition of metallic contacts via stencil mask technique and a sputtering chamber. For the sublimation of the organic compounds several effusion cells were designed. The evaporation characteristic and the temperature profile within the cells was studied. Additionally, a simulation program was developed, which calculates the evaporation characteristics of different cell types. The following processes were integrated: evaporation of particles, migration on the cell walls and collisions in the gas phase. It is also possible to consider a temperature gradient within the cell. All processes can be studied separately and their relative strength can be varied. To verify the simulation results several evaporation experiments with different cell types were employed. The thickness profile of the prepared thin films was measured position-dependently. The results are in good agreement with the simulation. Furthermore, the simulation program was extended to the field of electron beam induced deposition (EBID). The second part of this work deals with the preparation and characterization of organic thin films. The focus hereby lies on the charge transfer salt (BEDT-TTF)(TCNQ), which has three known structure variants. Thin films were prepared by different methods of co-evaporation and were studied with optical microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy (EDX).The formation of the monoclinic phase of (BEDT-TTF)(TCNQ) could be shown. As a last part tunnel structures were prepared as first thin film devices and measured in a He{sub 4} cryostat. (orig.)
17. Thermal stability and partial dewetting of crystalline organic thin films: 3,4,9,10-perylenetetracarboxylic dianhydride on Ag(111)
OpenAIRE
Krause, B.; Dürr, A. C.; Schreiber, F.; Dosch, H.; Seeck, O
2003-01-01
The thermal stability and dewetting effects of crystalline organic thin films on inorganic substrates have been investigated for a model system for organic epitaxy, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on Ag(111). The thin films deposited under a variety of growth conditions have been annealed stepwise and studied by in situ x-ray diffraction and noncontact atomic force microscopy. It has been found that comparatively smooth films deposited at temperatures T(g)less than or sim...
18. Solvent Vapor Treatment Effects on Poly(3-hexylthiophene Thin Films and its Application for Interpenetrating Heterojunction Organic Solar Cells
Directory of Open Access Journals (Sweden)
Masanori Ozaki
2010-11-01
Full Text Available The solvent vapor treatment (SVT for poly(3-hexylthiophene (PAT6 films and its application to interpenetrating heterojunction organic solar cells have been studied. It was found that SVT could improve the crystallinity and electrical characteristics of the PAT6 films. We fabricated organic solar cells with an interpenetrating structure of PAT6 and fullerenes utilizing the SVT process, and discuss the improved performance of the solar cells by taking the film crystallinity, optical properties, and morphology into consideration.
19. The Perfect Organism: the intruder of the Alien films as a bio-fictional construct
DEFF Research Database (Denmark)
Baron, Christian
2016-01-01
his film Quest for Fire (1981), as well as the fictional biology of the intruder in Ridley Scott’s Alien (1979) and some of its sequels, it introduces the notion of bio-fictional constructs as a term used to denote fictive and quasi-fictive organisms whose life cycle is either fully or partially...
20. Organic thin film transistors with polymer brush gate dielectrics synthesized by atom transfer radical polymerization
DEFF Research Database (Denmark)
Pinto, J.C.; Whiting, G.L.; Khodabakhsh, S.;
2008-01-01
Low operating voltage is an important requirement that must be met for industrial adoption of organic field-effect transistors (OFETs). We report here solution fabricated polymer brush gate insulators with good uniformity, low surface roughness and high capacitance. These ultra thin polymer films...
1. Antifouling polymeric films against marine organisms. Kaiyo seibutsu fuchaku boshi to kobunshi
Energy Technology Data Exchange (ETDEWEB)
Yamamori, N. (Nippon Paint Co. Ltd., Tokyo (Japan))
1991-07-15
An introduction is made on prevention of marine organisms from depositing on bridges and vessels, and on anti-fouling function of highly anti-fouling silicone resin and hydrolytic resins. First, in the case of silicone rubber, its surface is hydrophobic making it more difficult for sticking constituent (glycoprotein) in a depositing organism to deposit, in addition to its resilience, which sheds off easily the deposited organisms by its impact resilience. On the one hand, organism deposition can be prevented by means of micro-domain structure. Further, a description is given on the hydrolytic resins as to their anti-fouling agent releasing mechanism in hydrolytic paint film, and capability of prolonging the anti-fouling life by means of making the film thicker because the anti-fouling life is proportional to film thickness. In addition, explanations are given on elusion mechanism of hydrolytic resins, their behaviors in anti-fouling agent dispersion, the importance of controlling the elusion since the film elusion amount is an important factor to determine the release amount of the dispersed anti-fouling agent and the anti-fouling life, and the improvement of anti-fouling performance of the resins by means of adding monobasic acid into copper-acrylic resin. 9 refs., 13 figs., 8 tabs.
2. Large nonlinear optical activity from hybrid inorganic–organic films with fluorinated benzene as isolation group
International Nuclear Information System (INIS)
Two azo chromophores containing fluorinated benzene and alkyl chain as isolation group were designed and synthesized, respectively, and the corresponding alkoxysilane dyes were obtained by coupling 3-isocyanatopropyltriethoxysilane with the chromophores. The molecular structures were verified by elemental analysis, hydrogen nuclear magnetic resonance, and Fourier transform infrared spectrum. Followed by a sol–gel process of the alkoxysilane dyes, inorganic–organic hybrid films were prepared by spin-coating. After electric poling, these hybrid films show the higher nonlinear optical (NLO) response than their analog containing chromophore DR1. Furthermore, the fluorinated benzene group exhibits better enhanced effect than the flexible alkyl group. The highest NLO coefficients (d33) of the hybrid film containing fluorinated benzene group was determined to be 140.5 pm V−1 at the chromophore concentration of 40%. - Highlights: • Inorganic-organic hybrid films are prepared via sol-gel process of alkoxysilane dyes • Nonlinear optical properties of hybrid films are investigated • Fluorinated benzene group effectively improves the nonlinear optical property
3. Organic luminescent materials. First results on synthesis and characterization of Alq{sub 3} thin films
Energy Technology Data Exchange (ETDEWEB)
Baldacchini, G.; Gagliardi, S.; Montereali, R.M.; Pace, A. [ENEA, Centro Ricerche Frascati, Frascati, RM (Italy). Div. Fisica Applicata; Balaji Pode, R. [Nagpur University, Nagpur (India). Dept. of Physics
2000-07-01
Inorganic semiconductor diodes brought a technological revolution in the field of efficient light and laser sources in the last 20 years. New development in this field are expected from organic compounds, thanks to their low cost of synthesis and the relative easiness of growth as thin films. In particular, electrically pumped luminescent devices based on organic thin layers are among the most promising systems for next generation flat panel displays and semiconductor lasers. The tris - (8-hydroxy quinoline)-aluminium complex-Alq{sub 3} - is one of the most studied electro luminescent materials. In this paper, after a short introduction regarding historical development in the field, are reported preliminary results on the growth of Alq{sub 3} films and on their optical and spectroscopic characterization. [Italian] Negli ultimi 20 anni i diodi semiconduttori hanno portato una rivoluzione tecnologica nel campo delle sorgenti luminose e laser. Un nuovo sviluppo possibile in questo campo sono i composti organici, grazie al basso costo di sintesi e la relativa facilita' di crescerli in forma di film sottile. In particolare, dispositivi luminescenti pompati elettricamente basati su film sottili di materiali organici sono promettenti per una nuova generazione di display per schermi piatti e laser a Alq{sub 3} e' uno dei materiali elettroluminescenti piu' studiati. In questo rapporto, dopo una breve introduzione sullo sviluppo storico in questo campo, presentiamo i nostri primi risultati sulla crescita e caratterizzazione ottica di film di Alq{sub 3}.
4. Lithography-Free Broadband Ultrathin-Film Absorbers with Gap-Plasmon Resonance for Organic Photovoltaics.
Science.gov (United States)
Choi, Minjung; Kang, Gumin; Shin, Dongheok; Barange, Nilesh; Lee, Chang-Won; Ko, Doo-Hyun; Kim, Kyoungsik
2016-05-25
Strategies to confine electromagnetic field within ultrathin film emerge as essential technologies for applications from thin-film solar cells to imaging and sensing devices. We demonstrate a lithography-free, low-cost, large-scale method to realize broadband ultrathi-film metal-dielectric-metal (MDM) absorbers, by exploiting gap-plasmon resonances for strongly confined electromagnetic field. A two-steps method, first organizing Au nanoparticles via thermal dewetting and then transferring the nanoparticles to a spacer-reflector substrate, is used to achieve broader absorption bandwidth by manipulating geometric shapes of the top metallic layer into hemiellipsoids. A fast-deposited nominal Au film, instead of a conventional slow one, is employed in the Ostwald ripening process to attain hemiellipsoidal nanoparticles. A polymer supported transferring step allows a wider range of dewetting temperature to manipulate the nanoparticles' shape. By incorporating circularity with ImageJ software, the geometries of hemiellipsoidal nanoparticles are quantitatively characterized. Controlling the top geometry of MDM structure from hemisphere to hemiellipsoid increases the average absorption at 500-900 nm from 23.1% to 43.5% in the ultrathin film and full width at half-maximum of 132-324 nm, which is consistently explained by finite-difference time-domain simulation. The structural advantages of our scheme are easily applicable to thin-film photovoltaic devices because metal electrodes can act as metal reflectors and semiconductor layers as dielectric spacers. PMID:27160410
5. Optical performance of mesostructured composite silica film loaded with organic dye.
Science.gov (United States)
Guli, Mina; Chen, Shijian; Zhang, Dingke; Li, Xiaotian; Yao, Jianxi; Chen, Lei; Xiao, Li
2014-01-10
A mesoporous composite silica film loaded with organic dye has been successfully synthesized by a solgel reaction process and a simple postgrafting method at room temperature. The composite film was characterized by x-ray diffraction, transmission electron microscopy, UV-Vis, photoluminescence (PL) spectra, and laser performance, and the results confirmed the existence of dyes in the channels of the silica film. A blue-shift and fluorescence property in the PL spectrum was observed from the composite film compared with that of dye molecules in C₂H₅OH solution. The spectrum narrowing phenomena has been observed when the composite film is pumped at λp=355 nm by a Nd:YAG pulsed laser. A narrower, higher peak was observed in emission spectra from the mesostructured composite silica film compared with the PL spectrum of dye in C₂H₅OH solution. There is a substantial reduction in the full width at half-maximum of the emitting light, which results in peaks with linewidths of 26 nm or more. This collapse of the emission spectrum is one of the signatures of the presence of amplified spontaneous emission. PMID:24514063
6. Roughness development in electrodeposited soft magnetic CoNiFe films in the presence of organic additives
Directory of Open Access Journals (Sweden)
STEVE RIEMER
2003-05-01
Full Text Available The effects of three additives, sodium lauryl sulfate (NaLS, saccharin (Sacc, and NaLS + Sacc, on roughness development during the electrodeposition of CoNiFe films were investigated. The characterization of these films by atomic force microscopy shows that the electrodeposits produced from NaLS containing solution result in a rough surface. The role of NaLS surfactant is to change the interfacial tension and clean non-polar species like hydrogen bubbles from the surface. In Sacc containing solution, the evolution of a smooth surface is controlled by adsorbed Sacc molecule at the interface. The kinetic roughening of these deposits was investigated by dynamic scaling analysis. It was demonstrated that the roughness of CoNiFe films, obtained in the presence of NaLS + Sacc additives, was also dependent on current density, roughness of substrate, and the temperature of plating bath.
7. High-efficiency THz modulator based on phthalocyanine-compound organic films
International Nuclear Information System (INIS)
We report a high efficiency, broadband terahertz (THz) modulator following a study of phthalocyanine-compound organic films irradiated with an external excitation laser. Both transmission and reflection modulations of each organic/silicon bilayers were measured using THz time-domain and continuous-wave systems. For very low intensities, the experimental results show that AlClPc/Si can achieve a high modulation factor for transmission and reflection, indicating that AlClPc/Si has a superior modulation efficiency compared with the other films (CuPc and SnCl2Pc). In contrast, the strong attenuation of the transmitted and reflected THz waves revealed that a nonlinear absorption process takes place at the organic/silicon interface
8. High-efficiency THz modulator based on phthalocyanine-compound organic films
Science.gov (United States)
He, Ting; Zhang, Bo; Shen, Jingling; Zang, Mengdi; Chen, Tianji; Hu, Yufeng; Hou, Yanbing
2015-02-01
We report a high efficiency, broadband terahertz (THz) modulator following a study of phthalocyanine-compound organic films irradiated with an external excitation laser. Both transmission and reflection modulations of each organic/silicon bilayers were measured using THz time-domain and continuous-wave systems. For very low intensities, the experimental results show that AlClPc/Si can achieve a high modulation factor for transmission and reflection, indicating that AlClPc/Si has a superior modulation efficiency compared with the other films (CuPc and SnCl2Pc). In contrast, the strong attenuation of the transmitted and reflected THz waves revealed that a nonlinear absorption process takes place at the organic/silicon interface.
9. High-efficiency THz modulator based on phthalocyanine-compound organic films
Energy Technology Data Exchange (ETDEWEB)
He, Ting; Zhang, Bo, E-mail: [email protected], E-mail: [email protected]; Shen, Jingling, E-mail: [email protected], E-mail: [email protected]; Zang, Mengdi; Chen, Tianji [Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Hu, Yufeng; Hou, Yanbing [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China)
2015-02-02
We report a high efficiency, broadband terahertz (THz) modulator following a study of phthalocyanine-compound organic films irradiated with an external excitation laser. Both transmission and reflection modulations of each organic/silicon bilayers were measured using THz time-domain and continuous-wave systems. For very low intensities, the experimental results show that AlClPc/Si can achieve a high modulation factor for transmission and reflection, indicating that AlClPc/Si has a superior modulation efficiency compared with the other films (CuPc and SnCl{sub 2}Pc). In contrast, the strong attenuation of the transmitted and reflected THz waves revealed that a nonlinear absorption process takes place at the organic/silicon interface.
10. Solution coating of large-area organic semiconductor thin films with aligned single-crystalline domains
KAUST Repository
Diao, Ying
2013-06-02
Solution coating of organic semiconductors offers great potential for achieving low-cost manufacturing of large-area and flexible electronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of thin-film morphology. Here, we report an approach - termed fluid-enhanced crystal engineering (FLUENCE) - that allows for a high degree of morphological control of solution-printed thin films. We designed a micropillar-patterned printing blade to induce recirculation in the ink for enhancing crystal growth, and engineered the curvature of the ink meniscus to control crystal nucleation. Using FLUENCE, we demonstrate the fast coating and patterning of millimetre-wide, centimetre-long, highly aligned single-crystalline organic semiconductor thin films. In particular, we fabricated thin films of 6,13-bis(triisopropylsilylethynyl) pentacene having non-equilibrium single-crystalline domains and an unprecedented average and maximum mobilities of 8.1±1.2 cm2 V-1 s -1 and 11 cm2 V-1 s-1. FLUENCE of organic semiconductors with non-equilibrium single-crystalline domains may find use in the fabrication of high-performance, large-area printed electronics. © 2013 Macmillan Publishers Limited. All rights reserved.
11. Combinatorial Techniques to Efficiently Investigate and Optimize Organic Thin Film Processing and Properties
Directory of Open Access Journals (Sweden)
Hans-Werner Schmidt
2013-04-01
Full Text Available In this article we present several developed and improved combinatorial techniques to optimize processing conditions and material properties of organic thin films. The combinatorial approach allows investigations of multi-variable dependencies and is the perfect tool to investigate organic thin films regarding their high performance purposes. In this context we develop and establish the reliable preparation of gradients of material composition, temperature, exposure, and immersion time. Furthermore we demonstrate the smart application of combinations of composition and processing gradients to create combinatorial libraries. First a binary combinatorial library is created by applying two gradients perpendicular to each other. A third gradient is carried out in very small areas and arranged matrix-like over the entire binary combinatorial library resulting in a ternary combinatorial library. Ternary combinatorial libraries allow identifying precise trends for the optimization of multi-variable dependent processes which is demonstrated on the lithographic patterning process. Here we verify conclusively the strong interaction and thus the interdependency of variables in the preparation and properties of complex organic thin film systems. The established gradient preparation techniques are not limited to lithographic patterning. It is possible to utilize and transfer the reported combinatorial techniques to other multi-variable dependent processes and to investigate and optimize thin film layers and devices for optical, electro-optical, and electronic applications.
12. Nanoscale aluminum concaves for light-trapping in organic thin-films
Science.gov (United States)
Goszczak, Arkadiusz Jarosław; Adam, Jost; Cielecki, Paweł Piotr; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten
2016-07-01
Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation technique. Local ablation spots, corresponding to field enhancement on the ridge edges of the aluminum concave nanostructures, are observed in surface-covering polymer films, and confirmed with FDTD studies. The field enhancement leads to improved light absorption in the applied polymer layers, which may be used as an efficient method for enhancing the power conversion efficiency of organic solar cells.
13. Trapping light with micro lenses in thin film organic photovoltaic cells.
Science.gov (United States)
Tvingstedt, Kristofer; Dal Zilio, Simone; Inganäs, Olle; Tormen, Massimo
2008-12-22
We demonstrate a novel light trapping configuration based on an array of micro lenses in conjunction with a self aligned array of micro apertures located in a highly reflecting mirror. When locating the light trapping element, that displays strong directional asymmetric transmission, in front of thin film organic photovoltaic cells, an increase in cell absorption is obtained. By recycling reflected photons that otherwise would be lost, thinner films with more beneficial electrical properties can effectively be deployed. The light trapping element enhances the absorption rate of the solar cell and increases the photocurrent by as much as 25%. PMID:19104592
14. Quantitative analysis and optimization of gravure printed metal ink, dielectric, and organic semiconductor films.
Science.gov (United States)
Higgins, Stuart G; Boughey, Francesca L; Hills, Russell; Steinke, Joachim H G; Muir, Beinn V O; Campbell, Alasdair J
2015-03-11
Here we demonstrate the optimization of gravure printed metal ink, dielectric, and semiconductor formulations. We present a technique for nondestructively imaging printed films using a commercially available flatbed scanner, combined with image analysis to quantify print behavior. Print speed, cliché screen density, nip pressure, the orientation of print structures, and doctor blade extension were found to have a significant impact on the quality of printed films, as characterized by the spreading of printed structures and variation in print homogeneity. Organic semiconductor prints were observed to exhibit multiple periodic modulations, which are correlated to the underlying cell structure. PMID:25646647
15. Electric dipolar interaction assisted growth of single crystalline organic thin films
Energy Technology Data Exchange (ETDEWEB)
Jin-ming, Cai [Material Science and Technology Division, Oak Ridge National Laboratory; Yu-Yang, Zhang [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Hao, Hu [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Li-Hong, Bao [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Li-Da, Pan [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Wei, Tang [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Guo, Li [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Shi-Xuan, Du [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Jian, Shen [Material Science and Technology Division, Oak Ridge National Laboratory; Hong-Jun, Gao [Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2010-01-01
We report on a forest-like-to-desert-like pattern evolution in the growth of an organic thin film observed by using an atomic force microscope. We use a modified diffusion limited aggregation model to simulate the growth process and are able to reproduce the experimental patterns. The energy of electric dipole interaction is calculated and determined to be the driving force for the pattern formation and evolution. Based on these results, single crystalline films are obtained by enhancing the electric dipole interaction while limiting effects of other growth parameters.
16. Nanoscale aluminum concaves for light-trapping in organic thin-films
DEFF Research Database (Denmark)
Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten
2016-01-01
Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation...... technique. Local ablation spots, corresponding to field enhancement on the ridge edges of the aluminum concave nanostructures, are observed in surface-covering polymer films, and confirmed with FDTD studies. The field enhancement leads to improved light absorption in the applied polymer layers, which may be...... used as an efficient method for enhancing the power conversion efficiency of organic solar cells....
17. In situ spectroelectrochemical and theoretical study on the oxidation of a 4H-imidazole-ruthenium dye adsorbed on nanocrystalline TiO2 thin film electrodes.
Science.gov (United States)
Zhang, Ying; Kupfer, Stephan; Zedler, Linda; Schindler, Julian; Bocklitz, Thomas; Guthmuller, Julien; Rau, Sven; Dietzek, Benjamin
2015-11-28
Terpyridine 4H-imidazole-ruthenium(II) complexes are considered promising candidates for use as sensitizers in dye sensitized solar cells (DSSCs) by displaying broad absorption in the visible range, where the dominant absorption features are due to metal-to-ligand charge transfer (MLCT) transitions. The ruthenium(III) intermediates resulting from photoinduced MLCT transitions are essential intermediates in the photoredox-cycle of the DSSC. However, their photophysics is much less studied compared to the ruthenium(II) parent systems. To this end, the structural alterations accompanying one-electron oxidation of the RuIm dye series (including a non-carboxylic RuIm precursor, and, carboxylic RuImCOO in solution and anchored to a nanocrystalline TiO2 film) are investigated via in situ experimental and theoretical UV-Vis absorption and resonance Raman (RR) spectroelectrochemistry. The excellent agreement between the experimental and the TDDFT spectra derived in this work allows for an in-depth assignment of UV-Vis and RR spectral features of the dyes. A concordant pronounced wavelength dependence with respect to the charge transfer character has been observed for the model system RuIm, and both RuImCOO in solution and attached on the TiO2 surface. Excitation at long wavelengths leads to the population of ligand-to-metal charge transfer states, i.e. photoreduction of the central ruthenium(III) ion, while high-energy excitation features an intra-ligand charge transfer state localized on the 4H-imidazole moiety. Therefore, these 4H-imidazole ruthenium complexes investigated here are potential multi-photoelectron donors. One electron is donated from MLCT states, and additionally, the 4H-imidazole ligand reveals electron-donating character with a significant contribution to the excited states of the ruthenium(III) complexes upon blue-light irradiation. PMID:26478575
18. Comparison of Structural and Electrochemical Properties of V2O5 Thin Films Prepared by Organic/Inorganic Precursors
International Nuclear Information System (INIS)
Vanadium pentoxide thin films were produced from organic and inorganic precursors by sol gel dip-coating method. Fourier transform infrared spectroscopy and UV Vis spectroscopy were made to figure out structural properties of the films. Electrochemical properties were investigated by cyclic voltammetry. The shape of the curves was in agreement with a typical diffusion controlled cyclic voltammograms of amorphous V2O5 films for a reversible lithium ion intercalation/deintercalation process showing yellow–green–blue multi-electrochromism. V2O5 films, synthesized from organic precursor, indicated lower band gap energy, higher charge capacity as well as homogeneous and low granule size compared to inorganic route
19. Recent progress on thin-film encapsulation technologies for organic electronic devices
Science.gov (United States)
Yu, Duan; Yang, Yong-Qiang; Chen, Zheng; Tao, Ye; Liu, Yun-Fei
2016-03-01
Among the advanced electronic devices, flexible organic electronic devices with rapid development are the most promising technologies to customers and industries. Organic thin films accommodate low-cost fabrication and can exploit diverse molecules in inexpensive plastic light emitting diodes, plastic solar cells, and even plastic lasers. These properties may ultimately enable organic materials for practical applications in industry. However, the stability of organic electronic devices still remains a big challenge, because of the difficulty in fabricating commercial products with flexibility. These organic materials can be protected using substrates and barriers such as glass and metal; however, this results in a rigid device and does not satisfy the applications demanding flexible devices. Plastic substrates and transparent flexible encapsulation barriers are other possible alternatives; however, these offer little protection to oxygen and water, thus rapidly degrading the devices. Thin-film encapsulation (TFE) technology is most effective in preventing water vapor and oxygen permeation into the flexible devices. Because of these (and other) reasons, there has been an intense interest in developing transparent barrier materials with much lower permeabilities, and their market is expected to reach over 550 million by 2025. In this study, the degradation mechanism of organic electronic devices is reviewed. To increase the stability of devices in air, several TFE technologies were applied to provide efficient barrier performance. In this review, the degradation mechanism of organic electronic devices, permeation rate measurement, traditional encapsulation technologies, and TFE technologies are presented.
20. Preparation and characterization of LaNiO3 films grown by metal–organic deposition
Indian Academy of Sciences (India)
Yao Wang; Guofang Zhang; Chengshan Li; Guo Yan; Yafeng Lu
2011-12-01
We have investigated the synthesis and characterization of LaNiO3 (LNO) layers deposited on YSZ (100) substrate by metal–organic deposition (MOD). Texture, morphology and electrical properties of the LaNiO3 films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and electrical resistivity measurement. It has been found that the formation of (ℎ00) orientation depends on pyrolysis temperature, annealing temperature and thickness of LaNiO3 layers. The LaNiO3 films prepared under optimal condition indicate highly (ℎ00) orientation and a rather smooth surface. The LaNiO3 films show a metallic behaviour in the measured temperature range.
1. Inverted organic solar cells employing RGO/TiOx composite films as electron transport layers
International Nuclear Information System (INIS)
Reduced graphene oxide (RGO)/titanium oxide (TiOx) (RGO/TiOx) composite films are successfully prepared by a sol-gel method. Inverted organic solar cells incorporating RGO/TiOx composite as electron transport layer and MoO3 as hole transport layer were fabricated. A short-circuit current of 9.85 mA/cm2 and power conversion efficiency of 3.82% are achieved by using the RGO/TiOx composite films with 0.083 mg/mL of RGO in TiO2 colloidal solution as electron transport layers for the inverted solar cells based on P3HT and PCBM, which are increased by 14.8% and 26.1% compared with the reference device without RGO, respectively. Impedance measurements revealed that the significantly enhanced efficiency was attributed to the RGO/TiOx composite films with efficient electron transport
2. Nanobiohybrid structures based on the organized films of photosensitive membrane proteins
International Nuclear Information System (INIS)
The fundamental principles and technologies for the design of stable film systems based on biomembranes, photosensitive membrane proteins and complexes (retinal-containing proteins, reaction centres of photosynthetic bacteria, light-harvesting complexes of photosystems I and II), including their associates with metal and metal oxide nanoparticles or quantum dots are described. The advantages of controlled incorporation of the semiconductor or plasmonic nanocrystals into the biohybrid film structures are analyzed, first of all, the increase in the wavelength range of solar light harvesting and effective transfer of collected energy to the biological chromophores. Particular attention is devoted to the production of ultrathin and highly organized films at interfaces as the key stage of the design of nanobiohybrid materials with particular properties for photovoltaics, optoelectronics and nanophotonics. The bibliography includes 182 references
3. High mobility InN films grown by metal-organic vapor phase epitaxy
International Nuclear Information System (INIS)
We have grown single crystalline InN films on sapphire substrate using metal-organic vapor phase epitaxy (MOVPE). Electron mobility exceeding 1100 cm2/V sec was obtained for the as-grown films, with a donor concentration of 1-2 x 1019 cm-3. The observed mobility was higher than other reports using the MOVPE technique, and was comparable to the best results with similar carrier concentration using molecular beam epitaxy. Photoluminescence measurement showed a broad emission near 1.6 μm, indicating a likely narrow bandgap similar to many recent reports on InN. X-ray photoelectron spectroscopic analysis revealed little oxygen in the InN films grown. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
4. Transporting method for adsorbing tower and the adsorbing tower
International Nuclear Information System (INIS)
A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)
5. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region
KAUST Repository
Chakraborty, Anutosh
2009-07-07
The Henry coefficients of a single component adsorbent + adsorbate system are calculated from experimentally measured adsorption isotherm data, from which the heat of adsorption at zero coverage is evaluated. The first part of the papers relates to the development of thermodynamic property surfaces for a single-component adsorbent + adsorbate system1 (Chakraborty, A.; Saha, B. B.; Ng, K. C.; Koyama, S.; Srinivasan, K. Langmuir 2009, 25, 2204). A thermodynamic framework is presented to capture the relationship between the specific surface area (Ai) and the energy factor, and the surface structural and the surface energy heterogeneity distribution factors are analyzed. Using the outlined approach, the maximum possible amount of adsorbate uptake has been evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH° for (i) carbonaceous materials, metal organic frameworks (MOFs), carbon nanotubes, zeolites + hydrogen, and (ii) activated carbons + methane systems. The proposed theoretical framework of At and AH0 provides valuable guides for researchers in developing advanced porous adsorbents for methane and hydrogen uptake. © 2009 American Chemical Society.
6. Self-assembly of ferromagnetic organic-inorganic perovskite-like films.
Science.gov (United States)
Akhtar, Naureen; Polyakov, Alexey O; Aqeel, Aisha; Gordiichuk, Pavlo; Blake, Graeme R; Baas, Jacob; Amenitsch, Heinz; Herrmann, Andreas; Rudolf, Petra; Palstra, Thomas T M
2014-12-10
Perovskite-based organic-inorganic hybrids hold great potential as active layers in electronics or optoelectronics or as components of biosensors. However, many of these applications require thin films grown with good control over structure and thickness--a major challenge that needs to be addressed. The work presented here is an effort towards this goal and concerns the layer-by-layer deposition at ambient conditions of ferromagnetic organic-inorganic hybrids consisting of alternating CuCl4-octahedra and organic layers. The Langmuir-Blodgett technique used to assemble these structures provides intrinsic control over the molecular organization and film thickness down to the molecular level. Magnetic characterization reveals that the coercive field for these thin films is larger than that for solution-grown layered bulk crystals. The strategy presented here suggests a promising cost effective route to facilitate the excellently controlled growth of sophisticated materials on a wide variety of substrates that have properties relevant for the high density storage media and spintronic devices. PMID:25059565
7. [Effects of white organic light-emitting devices using color conversion films on electroluminescence spectra].
Science.gov (United States)
Hou, Qing-Chuan; Wu, Xiao-Ming; Hua, Yu-Lin; Qi, Qing-Jin; Li, Lan; Yin, Shou-Gen
2010-06-01
The authors report a novel white organic light-emitting device (WOLED), which uses a strategy of exciting organic/ inorganic color conversion film with a blue organic light-emitting diode (OLED). The luminescent layer of the blue OLED was prepared by use of CBP host blended with a blue highly fluorescent dye N-BDAVBi. The organic/inorganic color conversion film was prepared by dispersing a mixture of red pigment VQ-D25 and YAG : Ce3+ phosphor in PMMA. The authors have achieved a novel WOLED with the high color stability by optimizing the thickness and fluorescent pigment concentration of the color conversion film. When the driving voltage varied between 6 and 14 V, the color coordinates (CIE) varied slightly from (0.354, 0.304) to (0.357, 0.312) and the maximum current efficiency is about 5.8 cd x A(-1) (4.35 mA x cm(-2)), the maximum brightness is 16 800 cd x m(-2) at the operating voltage of 14 V. PMID:20707129
8. Substrate mediated growth of organic semiconducting thin films; Templateffekte bei der Strukturierung organischer Halbleiterfilme
Energy Technology Data Exchange (ETDEWEB)
Goetzen, Jan
2010-09-17
Since electronic properties of molecular materials are closely related to their structural order a precise control of the molecular packing and crystalline orientation of thin films is of vital interest for an optimization of organic electronic devices. Of particular interest in this respect is the initial stage of film formation which is largely governed by the interplay of intermolecular and molecule-substrate interactions. One approach to control the molecular film structure is based on substrate mediated growth. In this respect we have studied structural properties of thin films of pentacene, pentacene- 5,7,12,14-tetrone and perfluoro-pentacene which were grown onto various substrates including metals, metal oxides and graphite. On metal surfaces the molecules initially form a chemisorbed monolayer where molecules even can be uniformly aligned when using appropriate substrates with twofold symmetry. Further deposition, however, is accompanied by a pronounced dewetting and formation of disjoined islands which results from a large structural mismatch between the molecular arrangement in the monolayer and the crystalline phase. In some cases it is possible to orient such islands by utilizing step mediated nucleation and decoration of step bunches which allows the preparation of azimuthally well oriented elongated islands. On single crystalline oxides the growth parallels the situation found before for SiO{sub 2} where islands of upright oriented molecules are formed. The growth on graphite is somewhat particular since the lattice provides a natural template for acenes yielding epitaxially ordered monolayer films with planar adsorption geometry like in case of metals. Interestingly, however, no dewetting occurs upon further growth and instead rather smooth films are formed. The detailed analysis for the case of pentacene showed that the substrate-molecule interaction actually is weaker than the intermolecular interaction so that multilayer films can lift the
9. Polymer assisted solution processing of Ti-doped indium oxide transparent conducting thin films for organic solar cells
International Nuclear Information System (INIS)
Highlights: • Polymer assisted solution process. • Ti-doped indium oxide (TIO) transparent conducting films. • Replacement of sputtered ITO with polymer-assisted-solution-coated TIO films. • High mobility transparent conducting films. • Application of polymer-assisted-solution-coated TIO films to organic solar cells. - Abstract: We report the preparation and evaluation of Ti-doped indium oxide (TIO) transparent conducting films by a polymer-assisted solution (PAS) process, as well as the evaluation of this type of film as a transparent cathode in an inverted organic solar cell (IOCS). Both Ti- and In-PASs have been synthesized by coordinating Ti- and In-anionic complexes with polyethyleneimine. The final TIO–PAS was formed by mixing Ti-PAS into In-PAS with a Ti concentration between 1 at.% and 7 at.%. The TIO–PAS was spin-coated onto glass substrates to form uniform thin films of Ti-doped indium oxide, which were then annealed at high temperature. The optimum Ti concentration to achieve the best electrical and optical properties of PAS–TIO films was found to be 3 at.%. With the film thickness of 650 nm, PAS–TIO films had a sheet resistance of 65 Ω/sq and an optical transmittance greater than 85%. The feasibility of PAS-coated TIO thin film as a transparent electrode was evaluated by applying it to the fabrication of IOSCs, which showed the energy conversion efficiency of 4.60%
10. Organosilicon Ion-Exchange and Complexing Adsorbents
Institute of Scientific and Technical Information of China (English)
M. Voronkov; N. Vlasova; Yu. Pozhidaev; L. Belousova
2005-01-01
@@ 1Introduction Modification of mineral synthetic or natural substrates by organosilicon G-functionally substituted monomers, copolycondensation of the latter with organic and organosilicon compounds, and hydrolytic polycondensation of these monomers are the most widely used methods of synthesis of organosilicon adsorbents.
11. Improvement of the outcoupling efficiency of an organic light-emitting device by attaching microstructured films
Science.gov (United States)
Lin, Hoang-Yan; Lee, Jiun-Haw; Wei, Mao-Kuo; Dai, Ching-Liang; Wu, Chia-Fang; Ho, Yu-Hsuan; Lin, Hung-Yi; Wu, Tung-Chuan
2007-07-01
In this paper, we present and analyse the optical characteristics, such as spectral shift, CIE coordinates, viewing angle dependence, luminous current efficiency and luminous power efficiency, of an organic light-emitting device (OLED) with a commercial diffuser film or a brightness-enhancement film (BEF) attached. Compared to a planar green OLED, the luminous current efficiencies of the OLED with an attached diffuser film or BEF increase by 29% and 23%, respectively. The overall luminous power efficiencies are enhanced by 28% and 7%. Compared to the planar green device, we observe blue shifts at different viewing angles when microstructured films are attached, which is the evidence that the waveguiding modes are being extracted. In our planar OLED, the peak wavelength blue shifts and the full width at the half maximum (FWHM) decrease with increasing viewing angles due to the microcavity effect. When the diffuser is attached, the spectral peak has a constant blue shift (6 nm) compared to that of the planar OLED. On the other hand, in the BEF case, the spectral shift depends on the viewing angle (2-12 nm blue shifts from 0 to 80°). This is due to the different operating principles (scattering and redirected light) of the diffuser and BEF. Since the transmittance spectra of both the diffuser film and the BEF are flat over the visible range, it is suitable for lighting applications by using white OLED. When attaching the films on a commercial white OLED, the luminous current efficiencies of the OLED with an attached diffuser film or BEF increase by 34% and 31%, respectively. The overall luminous power efficiencies are enhanced by 42% and 8%.
12. An anode with aluminum doped on zinc oxide thin films for organic light emitting devices
International Nuclear Information System (INIS)
Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by DC reactive magnetron sputtering method. Films were deposited at a substrate temperature of 150-bar oC in 0.03 Pa of oxygen pressure. The electrical and optical properties of the film with the Al-doping amount of 2 wt% in the target were investigated. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 2 wt%, the lowest electrical resistivity was 4x10-4Ωcm and the average transmission in the visible range 400-700 nm was more than 90%. The AZO film was used as an anode contact to fabricate organic light-emitting diodes. The device performance was measured and the current efficiency of 2.9 cd/A was measured at a current density of 100 mA/cm2
13. Molecular organization in the thin films of chloroaluminium hexadecafluorophthalocyanine revealed by polarized Raman spectroscopy
International Nuclear Information System (INIS)
The molecular arrangement in the thin films of chloroaluminium hexadecafluorophthalocyanine (AlClPcF16) grown by physical vapor deposition has been studied using atomic force microscopy and optical spectroscopy techniques. It was shown that AlClPcF16 films, 20 nm thick, prepared on the quartz substrate at 60 °C are well organized and characterized by a predominantly co-facial parallel arrangement of molecules vertical to the surface. According to the polarized Raman spectroscopy measurements, the mean tilt angle between the AlClPcF16 species and the substrate surface was found to be 75 ± 5°. All intense bands in the experimental Infrared and Raman spectra of AlClPcF16 were assigned using density functional theory calculations. The theoretically predicted geometry and wavenumbers are in a good agreement with the experimental values. Apart from this, the temperature dependence of vapor pressure and sublimation enthalpy of AlClPcF16 were determined by the Knudsen effusion method. - Highlights: • Aluminium hexadecafluorophthalocyanine films were grown by physical vapor deposition. • Orientation of molecules in the films was studied using polarized Raman spectroscopy. • Films have a co-facial parallel arrangement of molecules vertical to the surface. • Temperature dependence of vapor pressure was determined by Knudsen effusion method
14. Organic self-assembled layer-by-layer thin films for second-order nonlinear optics
Science.gov (United States)
Guzy, Matthew T.
Layer-by-layer deposition techniques were used to fabricate films with second order nonlinear optical (NLO) properties. These materials are key to the development of electro-optic modulators used in fiber optic communication systems. Performance benefits and lower manufacturing costs are driving the development of organic NLO materials as replacements for inorganic crystalline materials such as lithium niobate. The layer-by-layer deposition technique in which polyelectrolytes are deposited on a surface by electrostatic effects is called the Ionically Self-Assembled Monolayer or ISAM method. The role of the optically inactive polycation's structure on deposition and chromophore orientation was studied by fabricating films with several different polycations. While the specific interactions responsible for chromophore orientation in ISAM films remains unclear, hydrogen bonding and electrostatic effects are ruled out as the sole sources of orientation. The highest values of chi(2) were observed under pH conditions that resulted in flat and thin layers. The relationship between pH and the optical homogeneity of the film was also explored. Deposition of polymers under pH conditions in which the polymer chains were aggregated in solution results in films that are not suitable for use in devices. In this work, a new layer-by-layer deposition technique was developed. Coined hybrid deposition, it relies on covalent bonds and electrostatic interactions for film fabrication. Optically inactive polyamines were used as sources of positive charges and as binding sites with optically active low molecular weight chromophores functionalized with a reactive triazine ring and negative charged sulfonate groups. Polar ordering of the chromophores was obtained when the deposition was done under conditions in which covalent bonding was the preferred attachment mechanism for the chromophore molecules. pH conditions in which electrostatic attachment dominated resulted in poorer orientation
15. Dielectric properties of crystalline organic molecular films in the limit of zero overlap
Energy Technology Data Exchange (ETDEWEB)
D’Avino, Gabriele, E-mail: [email protected] [Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, BE-7000 Mons, Belgium and Department of Physics, University of Liège, Allée du 6 Août 17, BE-4000 Liège (Belgium); Vanzo, Davide; Soos, Zoltán G., E-mail: [email protected] [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)
2016-01-21
We present the calculation of the static dielectric susceptibility tensor and dipole field sums in thin molecular films in the well-defined limit of zero intermolecular overlap. Microelectrostatic and charge redistribution approaches are applied to study the evolution of dielectric properties from one to a few molecular layers in films of different conjugated molecules with organic electronics applications. Because of the conditional convergence of dipolar interactions, dipole fields depend on the shape of the sample and different values are found in the middle layer of a thick film and in the bulk. The shape dependence is eliminated when depolarization is taken into account, and the dielectric tensor of molecular films converges to the bulk limit within a few molecular layers. We quantify the magnitude of surface effects and interpret general trends among different systems in terms of molecular properties, such as shape, polarizability anisotropy, and supramolecular organization. A connection between atomistic models for molecular dielectrics and simpler theories for polarizable atomic lattices is also provided.
16. Dielectric properties of crystalline organic molecular films in the limit of zero overlap
International Nuclear Information System (INIS)
We present the calculation of the static dielectric susceptibility tensor and dipole field sums in thin molecular films in the well-defined limit of zero intermolecular overlap. Microelectrostatic and charge redistribution approaches are applied to study the evolution of dielectric properties from one to a few molecular layers in films of different conjugated molecules with organic electronics applications. Because of the conditional convergence of dipolar interactions, dipole fields depend on the shape of the sample and different values are found in the middle layer of a thick film and in the bulk. The shape dependence is eliminated when depolarization is taken into account, and the dielectric tensor of molecular films converges to the bulk limit within a few molecular layers. We quantify the magnitude of surface effects and interpret general trends among different systems in terms of molecular properties, such as shape, polarizability anisotropy, and supramolecular organization. A connection between atomistic models for molecular dielectrics and simpler theories for polarizable atomic lattices is also provided
17. Continuous, Highly Flexible, and Transparent Graphene Films by Chemical Vapor Deposition for Organic Photovoltaics
KAUST Repository
Gomez De Arco, Lewis
2010-05-25
We report the implementation of continuous, highly flexible, and transparent graphene films obtained by chemical vapor deposition (CVD) as transparent conductive electrodes (TCE) in organic photovoltaic cells. Graphene films were synthesized by CVD, transferred to transparent substrates, and evaluated in organic solar cell heterojunctions (TCE/poly-3,4- ethylenedioxythiophene:poly styrenesulfonate (PEDOT:PSS)/copper phthalocyanine/fullerene/bathocuproine/aluminum). Key to our success is the continuous nature of the CVD graphene films, which led to minimal surface roughness (∼ 0.9 nm) and offered sheet resistance down to 230 Ω/sq (at 72% transparency), much lower than stacked graphene flakes at similar transparency. In addition, solar cells with CVD graphene and indium tin oxide (ITO) electrodes were fabricated side-by-side on flexible polyethylene terephthalate (PET) substrates and were confirmed to offer comparable performance, with power conversion efficiencies (η) of 1.18 and 1.27%, respectively. Furthermore, CVD graphene solar cells demonstrated outstanding capability to operate under bending conditions up to 138°, whereas the ITO-based devices displayed cracks and irreversible failure under bending of 60°. Our work indicates the great potential of CVD graphene films for flexible photovoltaic applications. © 2010 American Chemical Society.
18. Thin-film encapsulation of the air-sensitive organic-based ferrimagnet vanadium tetracyanoethylene
Energy Technology Data Exchange (ETDEWEB)
Froning, I. H.; Harberts, M.; Yu, H.; Johnston-Halperin, E., E-mail: [email protected] [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Lu, Y. [Department of Chemistry, The Ohio State University, Columbus, Ohio 43210-1173 (United States); Epstein, A. J. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Department of Chemistry, The Ohio State University, Columbus, Ohio 43210-1173 (United States)
2015-03-23
The organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]{sub x∼2}) has demonstrated potential for use in both microwave electronics and spintronics due to the combination of high temperature magnetic ordering (T{sub C} > 600 K), extremely sharp ferromagnetic resonance (peak to peak linewidth of 1 G), and low-temperature conformal deposition via chemical vapor deposition (deposition temperature of 50 °C). However, air-sensitivity leads to the complete degradation of the films within 2 h under ambient conditions, with noticeable degradation occurring within 30 min. Here, we demonstrate encapsulation of V[TCNE]{sub x∼2} thin films using a UV-cured epoxy that increases film lifetime to over 710 h (30 days) as measured by the remanent magnetization. The saturation magnetization and Curie temperature decay more slowly than the remanence, and the coercivity is unchanged after 340 h (14 days) of air exposure. Fourier transform infrared spectroscopy indicates that the epoxy does not react with the film, and magnetometry measurements show that the presence of the epoxy does not degrade the magnetic properties. This encapsulation strategy directly enables a host of experimental protocols and investigations not previously feasible for air-sensitive samples and lays the foundation for the development of practical applications for this promising organic-based magnetic material.
19. Highly Non-Linear Optical (NLO) organic crystals and films. Electrooptical organic materials
Science.gov (United States)
Mcmanus, Samuel P.; Rosenberger, Franz; Matthews, John
1987-01-01
Devices employing nonlinear optics (NLO) hold great promise for important applications in integrated optics, optical information processing and telecommunications. Properly designed organics possess outstanding optical and electrooptical properties which will substantially advance many technologies including electrooptical switching, optical amplification for communications, and parallel processing for hybrid optical computers. A brief comparison of organic and inorganic materials is given.
20. Growth of thin films of organic nonlinear optical materials by vapor growth processes - An overview and examination of shortfalls
Science.gov (United States)
Frazier, D. O.; Penn, B. G.; Witherow, W. K.; Paley, M. S.
1991-01-01
Research on the growth of second- and third-order nonlinear optical (NLO) organic thin film by vapor deposition is reviewed. Particular attention is given to the experimental methods for growing thin films of p-chlorophenylurea, diacetylenes, and phthalocyanines; characteristics of the resulting films; and approaches for advancing thin film technology. It is concluded that the growth of NLO thin films by vapor processes is a promising method for the fabrication of planar waveguides for nonlinear optical devices. Two innovative approaches are proposed including a method of controlling the input beam frequency to maximize nonlinear effects in thin films and single crystals, and the alternate approach to the molecular design of organic NLO materials by increasing the transition dipole moment between ground and excited states of the molecule.
1. Formation of molecular doping patterns in organic-inorganic hybrid films by a capillary electrophoresis doping technique
International Nuclear Information System (INIS)
A new technique is proposed for the fabrication of fine patterns of molecular doping in organic-inorganic hybrid materials by the combination of capillary electrophoresis doping (CED) and photolithography. The UV-induced polymerization of - -- C=C - -- bonds in organic groups yields a fine contrast of structures with the desired pattern in organic-inorganic hybrid films, and CED treatment introduces functional molecules only into unirradiated regions to form the doping patterns of molecules inside the films. The fine patterning of rhodamine-6G doping with from 2 to 4 μm resolution is demonstrated in hybrid films of 10 μm thickness.
2. Self-organization of crystalline domains in originally amorphous perylene diimide films
International Nuclear Information System (INIS)
Thin films (100-150 nm) of 1,6,7,10-tetra-chloro-N, N'-dimethyl-perylene-tetracarboxylic- bisimide (Cl4MePTCDI) were grown by physical vapour deposition on glass and characterized as being widely amorphous with a rather small degree of intermolecular electronic coupling. A slow reorganization process was detected upon conditioning the films in air by optical microscopy. Polarized microscopy and scanning force microscopy revealed the formation of crystalline domains. Locally resolved absorption and photoluminescence measurements were used to analyse changes in intermolecular coupling. Individual domains were studied by micro-photoluminescence and temperature-dependent photoluminescence was used to characterize the degree of intermolecular coupling in the crystalline domains. The results are discussed in view of recently proposed applications of such perylene imides with a twisted aromatic core in organic inverters and organic photovoltaic cells
3. Low voltage copper phthalocyanine organic thin film transistors with a polymer layer as the gate insulator
International Nuclear Information System (INIS)
Low voltage organic thin film transistors (OTFTs) were created using polymethyl-methacrylate-co g-lyciclyl-methacrylate (PMMA-GMA) as the gate dielectric. The OTFTs performed acceptably at supply voltages of about 10 V. From a densely packed copolymer brush, a leakage current as low as 2 x 10-8 A/cm2 was obtained. From the measured capacitance-insulator frequency characteristics, a dielectric constant in the range 3.9-5.0 was obtained. By controlling the thickness of the gate dielectric, the threshold voltage was reduced from -3.5 to -2.0 V. The copper phthalocyanine (CuPc) based organic thin film transistor could be operated at low voltage and 1.2 x 10-3 cm2/(V·s) mobility. (semiconductor devices)
4. Performance improvement in pentacene organic thin film transistors by inserting a C60 ultrathin layer
Institute of Scientific and Technical Information of China (English)
Sun Qin-Jun; Xu Zheng; Zhao Su-Ling; Zhang Fu-Jun; Gao Li-Yan
2011-01-01
The contact effect on the performances of organic thin film transistors is studied here. A C60 ultrathin layer is inserted between Al source-drain electrode and pentacene to reduce the contact resistance. By a 3 nm C60 modification,the injection harrier is lowered and the contact resistance is reduced. Thus, the field-effect mobility increases from 0.12to 0.52 cm2/(V.s). It means that inserting a C60 ultra thin layer is a good method to improve the organic thin film transistor (OTFT) performance. The output curve is simulated by using a charge drift model. Considering the contact of OTFTs should be carried out.
5. High brightness phosphorescent organic light emitting diodes on transparent and flexible cellulose films
International Nuclear Information System (INIS)
Organic light-emitting diodes (OLED) were fabricated on flexible and transparent reconstituted cellulose obtained from wood pulp. Cellulose is naturally available, abundant, and biodegradable and offers a unique substrate alternative for the fabrication of flexible OLEDs. Transparent cellulose material was formed by dissolution of cellulose in an organic solvent (dimethyl acetamide) at elevated temperature (165 °C) in the presence of a salt (LiCl). The optical transmission of 40-μm thick transparent cellulose sheet averaged 85% over the visible spectrum. High brightness and high efficiency thin film OLEDs were fabricated on transparent cellulose films using phosphorescent Ir(ppy)3 as the emitter material. The OLEDs achieved current and luminous emission efficiencies as high as 47 cd A−1 and 20 lm W−1, respectively, and a maximum brightness of 10 000 cd m−2. (paper)
6. High mobility high efficiency organic films based on pure organic materials
Science.gov (United States)
Salzman, Rhonda F.; Forrest, Stephen R.
2009-01-27
A method of purifying small molecule organic material, performed as a series of operations beginning with a first sample of the organic small molecule material. The first step is to purify the organic small molecule material by thermal gradient sublimation. The second step is to test the purity of at least one sample from the purified organic small molecule material by spectroscopy. The third step is to repeat the first through third steps on the purified small molecule material if the spectroscopic testing reveals any peaks exceeding a threshold percentage of a magnitude of a characteristic peak of a target organic small molecule. The steps are performed at least twice. The threshold percentage is at most 10%. Preferably the threshold percentage is 5% and more preferably 2%. The threshold percentage may be selected based on the spectra of past samples that achieved target performance characteristics in finished devices.
7. Photosensitive organized organic films in the light of bound electromagnetic waves
Science.gov (United States)
Sekkat, Zouheir; Knoll, Wolfgang
1997-01-01
This paper describes recent advances in the field of photochromic polymeric structures for optical data storage. In particular, we discuss photo-induced effects in supramolecular assemblies containing azobenzene molecules (e.g. Langmuir-Blodgett-Kuhn structures and ultrathin silane layers). Reorientation of azobenzenes in these structures is compared to that observed in spin-cast films. Photoisomerization and photo-induced orientation of azobenzene molecules is studied at the molecular level by means of azosilane molecules chemisorbed on silicon oxide substrates. The study of the thermal back isomerization reaction of the azobenzene molecules in these layers reveals steric hindrance at the molecular level. These ultra-thin photochromic self-assembled monolayers (SAMs) exhibit persistent dichroism upon linearly polarized light irradiation. This dichroism could be both written and erased by irradiation with light of an appropriate wavelength. In addition, the sign of this dichroism can be inverted by choosing the appropriate polarization of the irradiating light, thus showing a 'smart communication' between the light polarization and the ultra-thin photochromic layers. Photoisomerization also induces reversible changes in the optical thickness of these molecularly thin SAMs. Langmuir- Blodgett-Kuhn (LBK) multilayer assemblies of 'hairy-rod' polyglutamates with stiff main chains and flexible side chains containing photochromic azo units exhibit a highly optically anisotropic structure when the azo molecules are in the trans form, and a nearly optically isotropic structure when the azo molecules are in the cis form. The trans \$ARLR cis photoisomerization of the azo molecules switches them between a highly oriented trans configuration and a bend cis configuration, thus turning the anisotropy 'on' and 'off.' In contrast to spin-cast polymer films containing azobenzene units, photoselection under polarized light irradiation does not occur in these LBK structures. The
8. High index of refraction films for dielectric mirrors prepared by metal-organic chemical vapor deposition
International Nuclear Information System (INIS)
A wide variety of metal oxides with high index of refraction can be prepared by Metal-Organic Chemical Vapor Deposition. We present some recent optical and laser damage results on oxide films prepared by MOCVD which could be used in a multilayer structure for highly reflecting (HR) dielectric mirror applications. The method of preparation affects both optical properties and laser damage threshold. 10 refs., 8 figs., 4 tabs
9. Hybrid organic-inorganic coatings and films containing conducting polyaniline nanoparticles
Czech Academy of Sciences Publication Activity Database
Špírková, Milena; Stejskal, Jaroslav; Prokeš, J.
2004-01-01
Roč. 212, č. 1 (2004), s. 343-348. ISSN 1022-1360. [Electrical and Related Properties of Polymers and Other Organic Solids /9./. Prague, 14.07.2002-18.07.2002] R&D Projects: GA AV ČR KSK4050111; GA ČR GA203/01/0735 Institutional research plan: CEZ:AV0Z4050913 Keywords : atomic force microscopy * films * hybrid networks Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.691, year: 2004
10. Comparative study of the growth of sputtered aluminum oxide films on organic and inorganic substrates
OpenAIRE
Sellner, Stefan; Gerlach, Alexander; Kowarik, Stefan; Schreiber, Frank; Dosch, Helmut; Meyer, Stephan; Pflaum, Jens; Ulbricht, Gerhard
2007-01-01
We present a comparative study of the growth of the technologically highly relevant gate dielectric and encapsulation material aluminum oxide in inorganic and also organic heterostructures. Atomic force microscopy studies indicate strong similarities in the surface morphology of aluminum oxide films grown on these chemically different substrates. In addition, from X-ray reflectivity measurements we extract the roughness exponent \\beta of aluminum oxide growth on both substrates. By renormalis...
11. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks
OpenAIRE
Wencai Zhou; Christof Wöll; Lars Heinke
2015-01-01
The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs), is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM), the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diff...
12. Improved sensor selectivity for chemical vapors using organic thin-film transistors
OpenAIRE
Royer, James Edward
2012-01-01
Organic thin-film transistors (OTFTs) offer unique methods for chemical vapor detection due to multiple device parameters which are influenced by reactive gases. The simplest conventional readout for OTFT sensors is the drain current; however, the drain current is dependent on changes in fundamental device characteristics such as mobility and/or threshold voltage. The chemical properties of the analyte determine whether the mobility or threshold voltage response is dominant for the OTFT. The ...
13. Photoactive self-assembled monolayers for optically switchable organic thin-film transistors
OpenAIRE
Salinas, Michael; Halik, Marcus
2013-01-01
We investigate the photoconductive and photovoltaic effects in organic thin-film transistors with thin hybrid dielectrics composed of aluminum oxide and self-assembled monolayers (SAMs). By using SAM molecules with an electro-optical functionality tuning of the photoinduced charge transfer at the interface of semiconductor and SAM upon illumination with laser light can be achieved. Control of the threshold voltage by the SAM composition enables the optical operation of the transistors without...
14. Organic Self-Assembled Layer-by-Layer Thin Films for Second-Order Nonlinear Optics
OpenAIRE
Guzy, Matthew Thomas
2003-01-01
Layer-by-layer deposition techniques were used to fabricate films with second order nonlinear optical (NLO) properties. These materials are key to the development of electro-optic modulators used in fiber optic communication systems. Performance benefits and lower manufacturing costs are driving the development of organic NLO materials as replacements for inorganic crystalline materials such as lithium niobate. The layer-by-layer deposition technique in which polyelectrolytes are deposit...
15. Ultraselective Gas Separation by Nanoporous Metal-Organic Frameworks Embedded in Gas-Barrier Nanocellulose Films.
Science.gov (United States)
Matsumoto, Makoto; Kitaoka, Takuya
2016-03-01
Metal-organic frameworks (MOFs) are synthesized at carboxy groups on crystalline TEMPO-oxidized cellulose nanofibers (TOCNs). MOF-TOCN films coated on a paper filter have a hierarchical structure from the nano- to macroscale, and demonstrate a high CO2 /CH4 selectivity, over 120 for CO2 at a high gas flux, by the combination of the nanoporous MOFs and the gas-barrier TOCNs, which have strong affinity with each other. PMID:26669724
16. Langmuir-Blodgett films of micron-sized organic and inorganic colloids.
Science.gov (United States)
Reculusa, Stéphane; Perrier-Cornet, Romain; Agricole, Béatrice; Héroguez, Valérie; Buffeteau, Thierry; Ravaine, Serge
2007-12-28
Multilayered films starting with silica or polymer particles in the micron-size range have been prepared using the Langmuir-Blodgett technique. The polymer particles made of highly cross-linked cores and hydrophilic shells were elaborated through a precipitation polymerization method that allows formation of particles with a low polydispersity. The influence of the surface function, the differences between organic and inorganic systems, and the characterization of these materials by means of reflectance infrared spectroscopy are also discussed. PMID:18060168
17. The formation of organic (propolis films)/inorganic (layered crystals) interfaces for optoelectronic applications
Science.gov (United States)
Drapak, S. I.; Bakhtinov, A. P.; Gavrylyuk, S. V.; Kovalyuk, Z. D.; Lytvyn, O. S.
2008-10-01
Propolis (honeybee glue) organic films were prepared from an alcoholic solution on the surfaces of inorganic layered semiconductors (indium, gallium and bismuth selenides). Atomic force microscopy (AFM) and X-ray diffraction (XRD) are used to characterize structural properties of an organic/inorganic interfaces. It is shown that nanodimensional linear defects and nanodimensional cavities of various shapes are formed on the van der Waals (VDW) surfaces of layered crystals as a result of chemical interaction between the components of propolis (flavonoids, aminoacids and phenolic acids) and the VDW surfaces as well as deformation interaction between the VDW surfaces and propolis films during their polymerization. The nanocavities are formed as a result of the rupture of strong covalent bonds in the upper layers of layered crystals and have the shape of hexagons or triangles in the (0001) plane. The shape, lateral size and distribution of nanodimensional defects on the VDW surfaces depends on the type of crystals, the magnitude and distribution of surface stresses. We have obtained self-organized nanofold structures of propolis/InSe interface. It is established that such heterostructures have photosensitivity in the infrared range hν<1.2 eV (the values of energy gap are 1.2 eV for InSe and 3.07 eV for propolis films at room temperature).
18. The response of quartz crystals coated with thin fatty acid film to organic gases
International Nuclear Information System (INIS)
We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C14), palmitic acid (C16), stearic acid (C18), and arachidic acid (C20) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic gases was higher for higher molecular-weight gas, and we found that quartz crystals coated with stearic-acid LB film were more sensitive to organic gas than bare quartz crystals at room temperature
19. The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers
Science.gov (United States)
Hsu, Yu-Jen
Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by
20. NEXAF/XPS study of organic molecules adsorbed on rutile TiO2(110) and Al2O3/ Ni3Al(111) substrates
OpenAIRE
Naboka, Michael
2014-01-01
The spectroscopic studies of metal oxide surface interaction with different organic molecules have been performed for the needs of organic electronics, heterogeneous catalysis and surface chemistry. Three different systems: terephthalic acid (TPA) on rutile TiO2(110), azobenzene on rutile-TiO2(110), and tetracene on Al2O3/Ni3Al (111) were investigated.
1. An introduction to ultrathin organic films from Langmuir-Blodgett to self-assembly
CERN Document Server
Ulman, Abraham
1991-01-01
The development of oriented organic monomolecular layers by the Langmuir-Blodgett (LB) and self-assembly (SA) techniques has led researchers toward their goal of assembling individual molecules into highly ordered architectures. Thus the continually growing contribution of LB and SA systems to the chemistry and physics of thin organic films is widely recognized. Equally well-known is the difficulty in keeping up to date with the burgeoning multidisciplinary research in this area. Dr. Ulman provides a massive survey of the available literature. The book begins with a section on analytical tools
2. The interaction of organic adsorbate vibrations with substrate lattice waves in methyl-Si(111)-(1 × 1)
International Nuclear Information System (INIS)
A combined helium atom scattering and density functional perturbation theory study has been performed to elucidate the surface phonon dispersion relations for both the CH3-Si(111)-(1 × 1) and CD3-Si(111)-(1 × 1) surfaces. The combination of experimental and theoretical methods has allowed characterization of the interactions between the low energy vibrations of the adsorbate and the lattice waves of the underlying substrate, as well as characterization of the interactions between neighboring methyl groups, across the entire wavevector resolved vibrational energy spectrum of each system. The Rayleigh wave was found to hybridize with the surface rocking libration near the surface Brillouin zone edge at both the M¯-point and K¯-point. The calculations indicated that the range of possible energies for the potential barrier to the methyl rotation about the Si-C axis is sufficient to prevent the free rotation of the methyl groups at a room temperature interface. The density functional perturbation theory calculations revealed several other surface phonons that experienced mode-splitting arising from the mutual interaction of adjacent methyl groups. The theory identified a Lucas pair that exists just below the silicon optical bands. For both the CH3- and CD3-terminated Si(111) surfaces, the deformations of the methyl groups were examined and compared to previous experimental and theoretical work on the nature of the surface vibrations. The calculations indicated a splitting of the asymmetric deformation of the methyl group near the zone edges due to steric interactions of adjacent methyl groups. The observed shifts in vibrational energies of the -CD3 groups were consistent with the expected effect of isotopic substitution in this system
3. The interaction of organic adsorbate vibrations with substrate lattice waves in methyl-Si(111)-(1 × 1)
Energy Technology Data Exchange (ETDEWEB)
Brown, Ryan D.; Hund, Zachary M.; Sibener, S. J., E-mail: [email protected] [The James Franck Institute and Department of Chemistry, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637 (United States); Campi, Davide; Bernasconi, M. [Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); O’Leary, Leslie E.; Lewis, Nathan S. [Beckman Institute and Kavli Nanoscience Institute, Division of Chemistry and Chemical Engineering, 210 Noyes Laboratory, 127-72, California Institute of Technology, Pasadena, California 91125 (United States); Benedek, G. [Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Donostia International Physics Center (DIPC), Universidad del País Vasco (EHU), 20018 Donostia / San Sebastian (Spain)
2014-07-14
A combined helium atom scattering and density functional perturbation theory study has been performed to elucidate the surface phonon dispersion relations for both the CH{sub 3}-Si(111)-(1 × 1) and CD{sub 3}-Si(111)-(1 × 1) surfaces. The combination of experimental and theoretical methods has allowed characterization of the interactions between the low energy vibrations of the adsorbate and the lattice waves of the underlying substrate, as well as characterization of the interactions between neighboring methyl groups, across the entire wavevector resolved vibrational energy spectrum of each system. The Rayleigh wave was found to hybridize with the surface rocking libration near the surface Brillouin zone edge at both the M{sup ¯}-point and K{sup ¯}-point. The calculations indicated that the range of possible energies for the potential barrier to the methyl rotation about the Si-C axis is sufficient to prevent the free rotation of the methyl groups at a room temperature interface. The density functional perturbation theory calculations revealed several other surface phonons that experienced mode-splitting arising from the mutual interaction of adjacent methyl groups. The theory identified a Lucas pair that exists just below the silicon optical bands. For both the CH{sub 3}- and CD{sub 3}-terminated Si(111) surfaces, the deformations of the methyl groups were examined and compared to previous experimental and theoretical work on the nature of the surface vibrations. The calculations indicated a splitting of the asymmetric deformation of the methyl group near the zone edges due to steric interactions of adjacent methyl groups. The observed shifts in vibrational energies of the -CD{sub 3} groups were consistent with the expected effect of isotopic substitution in this system.
4. Influence of deposition parameters on morphology, growth and structure of crystalline and amorphous organic thin films : (the case of perylene and alpha-NPD)
OpenAIRE
Niyamakom, Phenwisa
2008-01-01
A growing research effort in organic electronics has been developped rapidly to utilize the electronic and optical properties of organic materials (polymers and oligomers) and hybrids (organic-inorganic composites) through novel material synthesis, thin film deposition techniques and many mores. Several applications, e.g. organic thin film transistors (OTFTs) and organic light emitting devices (OLEDs), have been envisioned in both academic research and industry. An understanding of thin film ...
5. INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY
Energy Technology Data Exchange (ETDEWEB)
Teague, L.; Moth, M.; Anthony, J.
2012-05-03
Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in I{sub SD} during operation (V{sub G}=-40 V, V{sub SD}= -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.
6. Deposition of highly (111)-oriented PZT thin films by using metal organic chemical deposition
CERN Document Server
Bu, K H; Choi, D K; Seong, W K; Kim, J D
1999-01-01
Lead zirconate titanate (PZT) thin films have been grown on Pt/Ta/SiNx/Si substrates by using metal organic chemical vapor deposition with Pb(C sub 2 H sub 5) sub 4 , Zr(O-t-C sub 4 H sub 9) sub 4 , and Ti(O-i-C sub 3 H sub 7) sub 4 as source materials and O sub 2 as an oxidizing gas. The Zr fraction in the thin films was controlled by varying the flow rate of the Zr source material. The crystal structure and the electrical properties were investigated as functions of the composition. X-ray diffraction analysis showed that at a certain range of Zr fraction, highly (111)-oriented PZT thin films with no pyrochlore phases were deposited. On the other hand, at low Zr fractions, there were peaks from Pb-oxide phases. At high Zr fractions, peaks from pyrochlore phase were seen. The films also showed good electrical properties, such as a high dielectric constant of more than 1200 and a low coercive voltage of 1.35 V.
7. Charge Transfer-Induced Molecular Hole Doping into Thin Film of Metal-Organic Frameworks.
Science.gov (United States)
Lee, Deok Yeon; Kim, Eun-Kyung; Shrestha, Nabeen K; Boukhvalov, Danil W; Lee, Joong Kee; Han, Sung-Hwan
2015-08-26
Despite the highly porous nature with significantly large surface area, metal-organic frameworks (MOFs) can be hardly used in electronic and optoelectronic devices due to their extremely poor electrical conductivity. Therefore, the study of MOF thin films that require electron transport or conductivity in combination with the everlasting porosity is highly desirable. In the present work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity are synthesized using layer-by-layer and doctor blade coating techniques followed by iodine doping. The as-prepared and doped films are characterized using FE-SEM, EDX, UV/visible spectroscopy, XPS, current-voltage measurement, photoluminescence spectroscopy, cyclic voltammetry, and incident photon to current efficiency measurements. In addition, the electronic and semiconductor properties of the MOF films are characterized using Hall Effect measurement, which reveals that, in contrast to the insulator behavior of the as-prepared MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by charge transfer-induced hole doping into the frameworks. The observed charge transfer-induced hole doping phenomenon is also confirmed by calculating the densities of states of the as-prepared and iodine doped MOFs based on density functional theory. Photoluminescence spectroscopy demonstrates an efficient interfacial charge transfer between TiO2 and iodine doped MOFs, which can be applied to harvest solar radiations. PMID:26226050
8. Spin coated graphene films as the transparent electrode in organic photovoltaic devices
International Nuclear Information System (INIS)
Many research efforts have been devoted to the replacement of the traditional indium–tin-oxide (ITO) electrode in organic photovoltaics. Solution-based graphene has been identified as a potential replacement, since it has less than two percent absorption per layer, relative high carrier mobility, and it offers the possibility of deposition on large area and flexible substrates, compatible with roll to roll manufacturing methods. In this work, soluble reduced graphene films with high electrical conductivity and transparency were fabricated and incorporated in poly(3-hexylthiophene) [6,6]-phenyl-C61-butyric acid methyl ester photovoltaic devices, as the transparent electrode. The graphene films were spin coated on glass from an aqueous dispersion of functionalized graphene, followed by a reduction process combining hydrazine vapor and annealing under argon, in order to reduce the sheet resistance. The photovoltaic devices obtained from the graphene films showed lower performance than the reference devices with ITO, due to the higher sheet resistance (2 kΩ/sq) and the poor hydrophilicity of the spin coated graphene films.
9. Characterization of amorphous organic thin films, determination of precise model for spectroscopic ellipsometry measurements
Energy Technology Data Exchange (ETDEWEB)
Farahzadi, Azadeh, E-mail: [email protected] [Institute of Physics (IA), RWTH Aachen University of Technology, 52056 Aachen (Germany); Beigmohamadi, Maryam; Niyamakom, Phenwisa; Kremers, Stephan [Institute of Physics (IA), RWTH Aachen University of Technology, 52056 Aachen (Germany); Meyer, Nico; Heuken, Michael [AIXTRON AG, Kackertstr. 15-17, 52072 Aachen (Germany); Wuttig, Matthias [Institute of Physics (IA), RWTH Aachen University of Technology, 52056 Aachen (Germany)
2010-09-01
The optical properties of tris(8-hydroxyquinoline) aluminum (Alq{sub 3}), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1-1'biphenyl-4,4''diamine ({alpha}-NPD) and other amorphous organic materials for OLEDs application, e.g. 4,4-bis(2,2-diphenyl vinyl)-1,1-biphenyl (DPVBI) and Spiro-DPVBI have been studied by multi-angle spectroscopic ellipsometry (SE). The thin films of these materials have been deposited by organic vapor phase deposition (OVPD). The structural characterization has been performed using atomic force microscopy (AFM) and X-ray reflectometry (XRR). Comparison of the measurements using these different independent techniques enables the precise determination of the optical model for dielectric function of these thin films. The detail analyses on Alq{sub 3} and {alpha}-NPD show that the Kim model with Gaussian broadening provides a significantly better fit to the ellipsometry data than the frequently used harmonic oscillator model. This conclusion is further proved by performing similar measurements on other amorphous organic samples for OLEDs application, e.g. DPVBI and Spiro-DPVBI. This result can be explained by the characteristic features of electronic states in organic molecules.
10. Characterization of amorphous organic thin films, determination of precise model for spectroscopic ellipsometry measurements
International Nuclear Information System (INIS)
The optical properties of tris(8-hydroxyquinoline) aluminum (Alq3), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1-1'biphenyl-4,4''diamine (α-NPD) and other amorphous organic materials for OLEDs application, e.g. 4,4-bis(2,2-diphenyl vinyl)-1,1-biphenyl (DPVBI) and Spiro-DPVBI have been studied by multi-angle spectroscopic ellipsometry (SE). The thin films of these materials have been deposited by organic vapor phase deposition (OVPD). The structural characterization has been performed using atomic force microscopy (AFM) and X-ray reflectometry (XRR). Comparison of the measurements using these different independent techniques enables the precise determination of the optical model for dielectric function of these thin films. The detail analyses on Alq3 and α-NPD show that the Kim model with Gaussian broadening provides a significantly better fit to the ellipsometry data than the frequently used harmonic oscillator model. This conclusion is further proved by performing similar measurements on other amorphous organic samples for OLEDs application, e.g. DPVBI and Spiro-DPVBI. This result can be explained by the characteristic features of electronic states in organic molecules.
11. Polysilsesquioxanes for Gate-Insulating Materials of Organic Thin-Film Transistors
Directory of Open Access Journals (Sweden)
Kimihiro Matsukawa
2012-01-01
Full Text Available Printable organic thin-film transistor (O-TFT is one of the most recognized technical issues nowadays. Our recent progress on the formation of organic-inorganic hybrid thin films consists of polymethylsilsesquioxane (PMSQ, and its applications for the gate-insulating layer of O-TFTs are introduced in this paper. PMSQ synthesized in toluene solution with formic acid catalyst exhibited the electric resistivity of higher than 1014 Ω cm after thermal treatment at 150°C, and the very low concentration of residual silanol groups in PMSQ was confirmed. The PMSQ film contains no mobile ionic impurities, and this is also important property for the practical use for the gate-insulating materials. In the case of top-contact type TFT using poly(3-hexylthiophene (P3HT with PMSQ gate-insulating layer, the device properties were comparable with the TFTs having thermally grown SiO2 gate-insulating layer. The feasibility of PMSQ as a gate-insulating material for O-TFTs, which was fabricated on a flexible plastic substrate, has been demonstrated. Moreover, by the modification of PMSQ, further functionalities, such as surface hydrophobicity, high permittivity that allows low driving voltage, and photocurability that allows photolithography, could be appended to the PMSQ gate-insulating layers.
12. Hemolysis effect and calcium-phosphate precipitation of heat-organic-film treated magnesium
Institute of Scientific and Technical Information of China (English)
GAO Jia-cheng; QIAO Li-ying; LI Long-chuan; WANG Yong
2006-01-01
A heat-organic-films process was employed to induce calcium-phosphate apatites formation on magnesium, consequently the corrosion resistance and hemolysis properties of magnesium were improved for biomedical applications. Firstly, magnesium samples were heat-treated at 773 K for 10 h; secondly, stearic acid films were coated on the surface of the heat-treated magnesium.Then the surface modified magnesium was soaked in simulated body fluid (SBF) to test its corrosion resistance. The results show that the heat treatment process allows magnesium to form a dense oxide layer with a thickness of around 20 μm, thereby the surface modified magnesium has higher corrosion resistance. After 24 h in SBF island apatite was deposited on magnesium. The unevenly precipitates were characterized by XRD and FTIR as the mixture of hydroxyapatite(HA) and octacalcium phosphate(OCP). The preliminary hemolysis experiment indicates that untreated magnesium has hemolytic effect (about 60%); whereas the heat-organic film treated samples has no hemolytic effect. The mechanism of fast nucleation and growth of calcium-phosphate apatites on surface modified magnesium in SBF was also discussed.
13. Organic solar cells based on liquid crystalline and polycrystalline thin films
Science.gov (United States)
Yoo, Seunghyup
This dissertation describes the study of organic thin-film solar cells in pursuit of affordable, renewable, and environmentally-friendly energy sources. Particular emphasis is given to the molecular ordering found in liquid crystalline or polycrystalline films as a way to leverage the efficiencies of these types of cells. Maximum efficiencies estimated based on excitonic character of organic solar cells show power conversion efficiencies larger than 10% are possible in principle. However, their performance is often limited due to small exciton diffusion lengths and poor transport properties which may be attributed to the amorphous nature of most organic semiconductors. Discotic liquid crystal (DLC) copper phthalocyanine was investigated as an easily processible building block for solar cells in which ordered molecular arrangements are enabled by a self-organization in its mesophases. An increase in photocurrent and a reduction in series resistance have been observed in a cell which underwent an annealing process. X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements suggest that structural and morphological changes induced after the annealing process are related to these improvements. In an alternative approach, p-type pentacene thin films prepared by physical vapor deposition were incorporated into heterojunction solar cells with C60 as n-type layers. Power conversion efficiencies of 2.7% under broadband illumination (350--900 nm) with a peak external quantum efficiency of 58% have been achieved with the broad spectral coverage across the visible spectrum. Analysis using an exciton diffusion model shows this efficient carrier generation is mainly due to the large exciton diffusion length of pentacene films. Joint XRD and AFM studies reveal that the highly crystalline nature of pentacene films can account for the observed large exciton diffusion length. In addition, the electrical characteristics are studied as a function of light intensity using
14. Fabrication of continuous mesoporous organic-inorganic nanocomposite films for corrosion protection of stainless steel in PEM fuel cells
International Nuclear Information System (INIS)
Graphical abstract: Ordered mesoporous organic-inorganic composite film has been achieved by sol-gel and spin-coating techniques. We believe that the mesoporous composite films have a potential application as a protect coating of bipolar plate material. Display Omitted Research highlights: → Ordered mesoporous composite film was deposited on the 304 stainless steel. → This composite film exhibited excellent protective performance in 0.5 M H2SO4. → The film exhibited a high surface tension with water contact angle close to 90o. - Abstract: The organic-inorganic composite film was deposited on the 304 stainless steel as bipolar plate material for proton exchange membrane fuel cells by spin-coating method. As shown by XRD, N2 adsorption-desorption and TEM, the composite films exhibit ordered mesoporous structures. The corrosion tests in 0.5 M H2SO4 system displayed that, compared with 304SS, the composite films made corrosion potential shifted to positive direction by 250-1000 mV (SCE) and corrosion current decreased by 1-3 orders of magnitude. Wherein, the C-50-60% composite film showed the optimal protective performance, its corresponding potentiostatic polarization process was extremely stable in the simulated fuel cells environment.
15. Electrical and physicochemical properties of Poly(3,4-ethylenedioxythiophene)-based organic-inorganic hybrid conductive thin films
International Nuclear Information System (INIS)
Conductive polymer coating precursors were prepared using poly (3, 4-ehtylenedioxythiophene) (PEDOT) and three kinds of silane precursors (Q type, T type, and bridged T type) through an in-situ organic/inorganic hybrid sol-gel process. The spin-coated precursor films on Poly(ethyleneterephthalate) substrate exhibited fairly good surface resistance (∼ 104 Ω/□), transparency (∼ 80%) and pencil hardness (2 - 4 H). The solvent resistance of the film using 2, 5-bis (triethoxysilyl)-3, 4-ethylenedioxythiophene (BTES-EDOT) was excellent as compared with the films that used silane precursors due to a high degree of BTES-EDOT crosslinking in the hybrid film. Moreover, EDOT moiety in the BTES-EDOT molecule may contribute to homogeneous dispersion of the PEDOT in the organic-inorganic hybrid film.
16. Concurrent photocatalytic hydrogen production and organic degradation by a composite catalyst film in a two-chamber photo-reactor
OpenAIRE
X. Wang; LI, XY
2013-01-01
A novel visible light-driven photocatalyst film, MoS2/Ag/TiO2, was synthesized on a glass-fiber membrane. The composite catalyst film had a multi-layer structure with Ag as nanoconjunctions between the MoS2 and TiO2 layers. The catalyst film performed well for both photocatalytic hydrogen production and organic degradation in a two-chamber photo-reactor under either solar or visible light. Hydrogen was produced in the cathode side chamber while the model organic was decomposed in the anode si...
17. SUPERCRITICAL FLUID EXTRACTION OF PARTICULATE AND ADSORBENT MATERIALS
Science.gov (United States)
The report is a summary of work performed by PNL on the extraction of semivolatile organic materials (SVOCs), for example, polynuclear aromatic compounds, from various adsorbents and environmental matrices, using supercritical fluids (SCFs) as extractants. The results of the work...
18. Metal–organic framework thin films with well-controlled growth directions confirmed by x-ray study
Directory of Open Access Journals (Sweden)
Kazuya Otsubo
2014-12-01
Full Text Available Metal–organic frameworks (MOFs have attracted the attention of a variety of researchers because of their structural diversity and designability, and their varied physical properties based on their uniform microporosity. While MOFs are interesting as bulk materials, future applications in functional nanomaterials will require the use of MOFs as thin films, and to achieve this, several thin-film fabrication techniques have been developed. These techniques have provided rational design of a variety of MOF thin films; however, oriented crystal growth of a MOF thin film, which is mainly confirmed by X-ray diffraction, remains a challenge that should be addressed. In this article, we review thin-film fabrications and characterizations, and structural features of MOF thin films with perfect crystalline orientation.
19. Co-sputtered oxide thin film encapsulated organic electronic devices with prolonged lifetime
Energy Technology Data Exchange (ETDEWEB)
Wong, F.L.; Fung, M.K.; Ng, C.Y.; Ng, A.; Bello, I.; Lee, S.T.; Lee, C.S., E-mail: [email protected]
2011-11-30
Effective top-side thin film encapsulation for organic light-emitting devices (OLEDs) was achieved by deposition of a multi-layer water diffusion barrier stack to protect the device against moisture permeation. The barrier stack was formed by alternative depositions of co-oxide and fluorocarbon (CF{sub x}) films. The co-oxide layer was fabricated by magnetron co-sputtering of silicon dioxide (SiO{sub 2}) and aluminum oxide (Al{sub 2}O{sub 3}). While the CF{sub x} layer was formed by plasma enhanced chemical vapor deposition. The water vapor transmission rate of the optimized diffusion barrier stack can be down to 10{sup -6} g/m{sup 2}/day. The OLEDs encapsulated with the multilayer stack have been shown to have operation lifetime of over 18,000 h which is nearly the same as devices with conventional glass-cover encapsulation.
20. High efficiency THz-wave modulators based on conjugated polymer-based organic films
Science.gov (United States)
He, Ting; Zhang, Bo; Wang, Guo-cui; Zang, Meng-di; Hou, Yan-bing; Shen, Jing-ling
2016-02-01
A study of the modulation mechanisms of conjugated polymer-based organic films and high-efficiency, broadband and all-optically controlled terahertz modulators based on these films is presented in this paper. Under very low-level external laser excitation, modulation efficiency of more than 99% is achieved using MEH-PPV/Si, PFO/Si and F8BT/Si bilayers. By analyzing the changes in the photo-excited carrier density and photoconductivity with changes in the external laser intensity, we introduce a nonlinear photo-induced absorption process to explain the strong attenuation mechanism for the transmitted terahertz waves. Finally, a simple THz communication test is carried out to demonstrate the potential future applications of the high-efficiency all-optically controlled terahertz modulator.
1. Improved Performance by a Double-Insulator Layer in Organic Thin-Film Transistors
Institute of Scientific and Technical Information of China (English)
WANG Wei; SHI Jia-Wei; GUO Shu-Xu; ZHANG Hong-Mei; QUAN Bao-Fu; MA Dong-Ge
2006-01-01
@@ Organic thin film transistors based on pentacene are fabricated by the method of full evaporation. The thickness of insulator film can be controlled accurately, which influences the device operation voltage markedly. Compared to the devices with a single-insulator layer, the electric performance of devices by using a double-insulator as the gate dielectric has good improvement. It is found that the gate leakage current can be reduced over one order of magnitude, and the on-state current can be enhanced over one order of magnitude. The devices with double-insulator layer exhibit field-effect mobility as large as 0.14 cm2/Vs and near the zero threshold voltage.The results demonstrate that using a proper double insulator as the gate dielectrics is an effective method to fabricate OTFTs with high electrical performance.
2. Charge Transport in Thin Organic Semiconducting Films: Seebeck and Field Effect Studies
Science.gov (United States)
Böhm, W.; Fritz, T.; Leo, K.
1997-03-01
We have investigated the charge transport properties of vapor-deposited thin organic films, using the Seebeck effect for determining conduction type and Fermi energy and the field effect to measure mobility and total charge carrier density. We show that the combination of both techniques gives a complete picture of the electrical properties of the films. Wir untersuchen den Ladungsträgertransport in aufgedampften dünnen organischen Schichten, wobei der Seebeck-Effekt zur Bestimmung des Leitfähigkeitstyps und der Lage des Ferminiveaus und der Feldeffekt zur Bestimmung der Leitfähigkeit und der gesamten Ladungsträgerdichte benutzt wird. Es wird gezeigt, daß durch die Kombination beider Methoden ein geschlossenes Bild der elektrischen Eigenschaften erhalten wird.
3. High efficiency THz-wave modulators based on conjugated polymer-based organic films
International Nuclear Information System (INIS)
A study of the modulation mechanisms of conjugated polymer-based organic films and high-efficiency, broadband and all-optically controlled terahertz modulators based on these films is presented in this paper. Under very low-level external laser excitation, modulation efficiency of more than 99% is achieved using MEH-PPV/Si, PFO/Si and F8BT/Si bilayers. By analyzing the changes in the photo-excited carrier density and photoconductivity with changes in the external laser intensity, we introduce a nonlinear photo-induced absorption process to explain the strong attenuation mechanism for the transmitted terahertz waves. Finally, a simple THz communication test is carried out to demonstrate the potential future applications of the high-efficiency all-optically controlled terahertz modulator. (paper)
4. Solution-processed hybrid organic-inorganic complementary thin-film transistor inverter
Science.gov (United States)
Cheong, Heajeong; Kuribara, Kazunori; Ogura, Shintaro; Fukuda, Nobuko; Yoshida, Manabu; Ushijima, Hirobumi; Uemura, Sei
2016-04-01
We investigated hybrid organic-inorganic complementary inverters with a solution-processed indium-gallium-zinc-oxide (IGZO) n-channel thin-film transistor (TFT) and p-channel TFTs using the high-uniformity polymer poly[2,5-bis(alkyl)pyrrolo[3,4-c]pyrrolo-1,4(2H,5H)-dione-alt-5,5-di(thiophene-2-yl)-2,2-(E)-2-(2-(thiophen-2-yl)vinyl)thiophene] (PDVT-10). The IGZO TFT was fabricated at 150 °C for 1 min. It showed a high field-effect mobility of 0.9 cm2·V-1·s-1 and a high on/off current ratio of 107. A hybrid complementary inverter was fabricated by combining IGZO with a PDVT-10 thin-film transistor and its operation was confirmed.
5. FABRICATION AND CHARACTERIZATION OF ORGANIC THIN FILMS WITH NANO—STRUCTURE
Institute of Scientific and Technical Information of China (English)
TakashiH,Noritaka; ChenGuorong; 等
2002-01-01
A novel method of thin film formation of organic materials with nano-strucure has been successfully developed by using vacuum technique is proposed. The diarylethene(C18H18N2S2)was selected as a model compound for the evaluation of this method.Polymer,we found that the tendency of dye dispersion into the polymer is as follows:PC>PBzMA>PMMA>PHPMA,where no dispersion is observed for PHPMA under the condition of 115℃ for 24 hours ,Thin film of polymer alloy composed of PMMA and polystylene(PS) was loaded into a glass ample with diarylethene,and treated for three days at 100℃,Dispersed state of the dye was evaluated by transmission electron microscope,and concluded that the dye is distributed only in PS domains selectively.Photochromic properties of the PS domain will be evaluated by using a scanning nearfield optical microscope.
6. Determination of the transport levels in thin films of organic semiconductors
Energy Technology Data Exchange (ETDEWEB)
Krause, Stefan
2009-07-27
The approach of using the combination of Ultraviolet (UPS) and Inverse Photoemission (IPS) to determine the transport levels in thin films of organic semiconductors is the scope of this work. For this matter all influences on the peak position and width in Photoelectron Spectroscopy are discussed with a special focus on organic semiconductors. Many of these influences are shown with experimental results of the investigation of diindenoperylene on Ag(111). These findings are applied to inorganic semiconductors silicon in order to establish the use of UPS and IPS on a well-understood system. Finally, the method is used to determine the transport level of several organic semiconductors (PTCDA, Alq3, CuPc, DIP, PBI-H4) and the corresponding exciton binding energies are calculated by comparison to optical absorption data. (orig.)
7. Ultra-thin films of polysilsesquioxanes possessing 3-methacryloxypropyl groups as gate insulator for organic field-effect transistors
International Nuclear Information System (INIS)
Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups as an organic moiety of the side chain were synthesized by sol–gel condensation copolymerization of the corresponding trialkoxysilanes. The ultra-thin PSQ film with a radical initiator and a cross-linking agent was prepared by a spin-coating method, and the film was cured integrally at low temperatures of less than 120 °C through two different kinds of polymeric reactions, which were radical polymerization of vinyl groups and sol–gel condensation polymerization of terminated silanol and alkoxy groups. The obtained PSQ film showed the almost perfect solubilization resistance to acetone, which is a good solvent of PSQ before polymerization. It became clear by atomic force microscopy observation that the surface of the PSQ film was very smooth at a nano-meter level. Furthermore, pentacene-based organic field-effect transistor (OFET) with the PSQ film as a gate insulator showed typical p-channel enhancement mode operation characteristics and therefore the ultra-thin PSQ film has the potential to be applicable for solution-processed OFET systems. - Highlights: ► Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups were synthesized. ► The ultra-thin PSQ film could be cured at low temperatures of less than 120 °C. ► The PSQ film showed the almost perfect solubilization resistance to organic solvent. ► The surface of the PSQ film was very smooth at a nano-meter level. ► Pentacene-based organic field-effect transistor with the PSQ film was fabricated.
8. Effects of Alloying on the Optical Properties of Organic-Inorganic Lead Halide Perovskite Thin Films
Energy Technology Data Exchange (ETDEWEB)
Ndione, Paul F.; Li, Zhen; Zhu, Kai
2016-09-07
Complex refractive index and dielectric function spectra of organic-inorganic lead halide perovskite alloy thin films are presented, together with the critical-point parameter analysis (energy and broadening) of the respective composition. Thin films of methylammonium lead halide alloys (MAPbI3, MAPbBr3, MAPbBr2I, and MAPbBrI2), formamidinium lead halide alloys (FAPbI3, FAPbBr3, and FAPbBr2I), and formamidinium cesium lead halide alloys [FA0.85Cs0.15PbI3, FA0.85Cs0.15PbBrI2, and FA0.85Cs0.15Pb(Br0.4I0.6)3] were studied. The complex refractive index and dielectric functions were determined by spectroscopic ellipsometry (SE) in the photon energy range of 0.7-6.5 eV. Critical point energies and optical transitions were obtained by lineshape fitting to the second-derivative of the complex dielectric function data of these thin films as a function of alloy composition. Absorption onset in the vicinity of the bandgap, as well as critical point energies and optical band transition shift toward higher energies as the concentration of Br in the films increases. Cation alloying (Cs+) has less effect on the optical properties of the thin films compared to halide mixed alloys. The reported optical properties can help to understand the fundamental properties of the perovskite materials and also be used for optimizing or designing new devices.
9. In-situ study of pn-heterojunction interface states in organic thin film transistors
International Nuclear Information System (INIS)
In this paper, we have investigated the density of pn-heterojunction interface states by evaluating the threshold voltage shift with in-situ measurement of electrical characteristics of a sandwich fluorinated copper phthalocyanine/pentacene thin film transistor with various thicknesses of pentacene thin films. A threshold voltage (VT) undergoes a significant shift from + 20.6 to + 0.53 V with increasing the thickness of pentacene. When the thickness of pentacene is more than a critical thickness of 15 nm, VT undergoes hardly any shift. On the other hand, the value of mobility is lightly decreased with increasing the thickness of pentacene due to the effect of the bulk current. Thus the VT shift is attributed to the increase of drain current in the sandwich device. In order to explain the VT shift, a model was assumed in the linear region of thin film transistor operation and the VT shift agrees with a tan−1 function of film thickness. The total charge density (Q0) of 1.53 × 10−7 C/cm2 (9.56 × 1011 electrons or holes/cm2) was obtained. Furthermore, the VT shift and Q0 could be adjusted by selecting a p-type semiconductor. - Highlights: • A threshold voltage was in-situ measured in an organic sandwich thin film transistor. • Density of pn-heterojunction interface states by evaluating the threshold voltage shift. • The threshold voltage shift attributes to the increase of drain current. • In order to explain the threshold voltage shift, a model was assumed
10. Zeolite thin film-coated spherical end-face fiber sensors for detection of trace organic vapors
Science.gov (United States)
Ning, Xiangping; Zhao, Chun Liu; Yang, Jingyi; Chan, Chi Chiu
2016-04-01
A novel zeolite thin film-coated spherical end face fiber sensor for detection of trace organic vapors was experimentally demonstrated. The spherical end-face was fabricated by electrical arc discharge on the end face of a standard single-mode fiber. The proposed sensor comprise of the fiber's spherical end-face covered with a layer of zeolite thin film. The zeolite film and spherical end face constituted an arc-shaped inline Fabry-Perot (F-P) cavity, which improves the interference performance. The trace chemical vapor concentration was measured by monitoring the shift of F-P interference wavelength which induced by the organic vapor molecular adsorption of the zeolite film. The proposed trace organic vapors sensor performed with the enhanced sensitivity 0.91 nm/ppm with the range from 0 to 70 ppm.
11. Nanostructured thin films for organic photovoltaic cells and organic light-emitting diodes
Science.gov (United States)
Zheng, Ying
2009-12-01
Achieving efficient organic optoelectronic devices, such as organic photovoltaic (OPV) cells and organic light-emitting diodes (OLEDs), relies on the understanding of the formation of various organic nanostructures as well as the fundamental of physical processes in device operation. The research presented in this thesis systematically investigates the controlled growth of organic nanostructure through different approaches and their relationship to OPV cell performance. Moreover, new materials and device structure are explored to achieve efficient OLEDs, which also provide further insight of the physical processes governing the performance of these devices. We first investigated the phase separation process in a molecular mixed donor-acceptor (D -- A) bulk heterojunction (BHJ) composed of pentacene and C60 suing a combination of experimental and computational approaches. Both experiment characterization and the MD simulation reveals that strong aggregation of pentacene exists in the pentacene:C60 mixtures due to the strong pi -- pi interaction among pentacene molecules. By controlling the processing conditions to suppress the pentacene aggregation to nanoscale leads to higher device efficiency as the more photogenerated excitons are able to reach the D -- A interface and contribute to the photocurrent. To circumvent the limits on phase separated D -- A mixed heterojunction, an interdigitated D -- A BHJ is synthesized through the oblique angle deposition (OAD) of copper phthalocyanine (CuPc). The morphology of CuPc nanorod arrays grown under the OAD process can be controlled by careful selection of the processing conditions, and we have achieved a high density, vertically aligned, polycrystalline CuPc nanorod array with nanorod size as small as 20-30 nm. Successful infiltration of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) into the optimized CuPc nanorod arrays has resulted in doubling of the power conversion efficiency of the OPV cell over planar
12. Organic and organic-inorganic hybrid polymer thin films deposited by PECVD using TEOS and cyclohexene for ULSI interlayer-dielectric application
Science.gov (United States)
Seo, Hyeon Jin; Nam, Sang-Hun; Kim, Sungsoo; Boo, Jin-Hyo
2015-11-01
Organic and organic-inorganic hybrid polymer thin films were deposited on Si(1 0 0) substrates at various ratios of TEOS (tetraethoxysilane) to cyclohexene by the plasma enhanced chemical vapor deposition (PECVD) method. The as-grown polymerized thin films were first analyzed by FT-IR and XPS. The results of FT-IR showed that the hybrid polymer thin films were polymerized with each fragmented precursor. The XPS results showed the chemical species and binding energies of each species. The Si 2p core-level spectra from the hybrid polymer thin film showed the status of the Si oxidation number. Impedance analysis was utilized for the measurement of the capacitance values and I-V curves, and an ultra low-k value and leakage current density of 1.75 and 10-9 A/cm2 at 1 MV/cm were obtained, respectively.
13. Effect of fractal silver electrodes on charge collection and light distribution in semiconducting organic polymer films
Energy Technology Data Exchange (ETDEWEB)
Chamousis, RL; Chang, LL; Watterson, WJ; Montgomery, RD; Taylor, RP; Moule, AJ; Shaheen, SE; Ilan, B; van de Lagemaat, J; Osterloh, FE
2014-08-21
Living organisms use fractal structures to optimize material and energy transport across regions of differing size scales. Here we test the effect of fractal silver electrodes on light distribution and charge collection in organic semiconducting polymer films made of P3HT and PCBM. The semiconducting polymers were deposited onto electrochemically grown fractal silver structures (5000 nm x 500 nm; fractal dimension of 1.71) with PEDOT:PSS as hole-selective interlayer. The fractal silver electrodes appear black due to increased horizontal light scattering, which is shown to improve light absorption in the polymer. According to surface photovoltage spectroscopy, fractal silver electrodes outperform the flat electrodes when the BHJ film thickness is large (>400 nm, 0.4 V photovoltage). Photocurrents of up to 200 microamperes cm(-2) are generated from the bulk heterojunction (BHJ) photoelectrodes under 435 nm LED (10-20 mW cm(-2)) illumination in acetonitrile solution containing 0.005 M ferrocenium hexafluorophosphate as the electron acceptor. The low IPCE values (0.3-0.7%) are due to slow electron transfer to ferrocenium ion and due to shunting along the large metal-polymer interface. Overall, this work provides an initial assessment of the potential of fractal electrodes for organic photovoltaic cells.
14. Synchrotron-radiation XPS analysis of ultra-thin silane films: Specifying the organic silicon
Science.gov (United States)
Dietrich, Paul M.; Glamsch, Stephan; Ehlert, Christopher; Lippitz, Andreas; Kulak, Nora; Unger, Wolfgang E. S.
2016-02-01
The analysis of chemical and elemental in-depth variations in ultra-thin organic layers with thicknesses below 5 nm is very challenging. Energy- and angle-resolved XPS (ER/AR-XPS) opens up the possibility for non-destructive chemical ultra-shallow depth profiling of the outermost surface layer of ultra-thin organic films due to its exceptional surface sensitivity. For common organic materials a reliable chemical in-depth analysis with a lower limit of the XPS information depth z95 of about 1 nm can be performed. As a proof-of-principle example with relevance for industrial applications the ER/AR-XPS analysis of different organic monolayers made of amino- or benzamidosilane molecules on silicon oxide surfaces is presented. It is demonstrated how to use the Si 2p core-level region to non-destructively depth-profile the organic (silane monolayer) - inorganic (SiO2/Si) interface and how to quantify Si species, ranging from elemental silicon over native silicon oxide to the silane itself. The main advantage of the applied ER/AR-XPS method is the improved specification of organic from inorganic silicon components in Si 2p core-level spectra with exceptional low uncertainties compared to conventional laboratory XPS.
15. Chemical characterization of a marine conditioning film
Digital Repository Service at National Institute of Oceanography (India)
Garg, A.; Jain, A.; Bhosle, N.B.
in marine waters. Abundance and composition of neutral sugars and its composition are useful tools to assess the sources of organic matter (Cowie and Hedges, 1984; Skoog and Benner, 1997; D’Souza et al., 2005). Carbohydrate polymers appear to play... procedures and substratum surface properties may influence the chemical composition and the amount of the adsorbed material (Little and Zsolnay, 1985; Taylor et al., 1997; Compere et al., 2001). Changes in the chemical composition of the conditioning film...
16. The importance of spinning speed in fabrication of spin-coated organic thin film transistors: Film morphology and field effect mobility
International Nuclear Information System (INIS)
We have investigated the film morphology and the field effect mobility of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) thin films which were formed by spin coating on the SiO2 substrate with solution-processed graphene electrodes. The domain size and the density of aggregates in the C8-BTBT film showed the same dependence on the spinning speed. These competitive two factors (domain size and density of aggregates) give an optimum spinning speed, at which the field effect mobility of C8-BTBT transistor showed a maximum (2.6 cm2/V s). This result indicates the importance of spinning speed in the fabrication of solution processed organic thin film transistors by spin coating.
17. Filter-adsorber aging assessment
International Nuclear Information System (INIS)
An aging assessment of high-efficiency particulate (HEPA) air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission's (USNRC) Nuclear Plant Aging Research (NPAR) Program. This evaluation of the general process in which characteristics of these two components gradually change with time or use included the compilation of information concerning failure experience, stressors, aging mechanisms and effects, and inspection, surveillance, and monitoring methods (ISMM). Stressors, the agents or stimuli that can produce aging degradation, include heat, radiation, volatile contaminants, and even normal concentrations of aerosol particles and gasses. In an experimental evaluation of degradation in terms of the tensile breaking strength of aged filter media specimens, over forty percent of the samples did not meet specifications for new material. Chemical and physical reactions can gradually embrittle sealants and gaskets as well as filter media. Mechanisms that can lead to impaired adsorber performance are associated with the loss of potentially available active sites as a result of the exposure of the carbon to airborne moisture or volatile organic compounds. Inspection, surveillance, and monitoring methods have been established to observe filter pressure drop buildup, check HEPA filters and adsorbers for bypass, and determine the retention effectiveness of aged carbon. These evaluations of installed filters do not reveal degradation in terms of reduced media strength but that under normal conditions aged media can continue to effectively retain particles. However, this degradation may be important when considering the likelihood of moisture, steam, and higher particle loadings during severe accidents and the fact it is probable that the filters have been in use for an extended period
18. All solution processed organic thin film transistor-backplane with printing technology for electrophoretic display
Science.gov (United States)
Lee, Myung W.; Song, C.K.
2012-01-01
In this study, solution processes were developed for backplane using an organic thin film transistor (OTFT) as a driving device for an electrophoretic display (EPD) panel. The processes covered not only the key device of OTFTs but also interlayer and pixel electrodes. The various materials and printing processes were adopted to achieve the requirements of devices and functioning layers. The performance of OTFT of the backplane was sufficient to drive EPD sheet by producing a mobility of 0.12 cm2/v x sec and on/off current ratio of 10(5).
19. Detection of saliva-range glucose concentrations using organic thin-film transistors
Science.gov (United States)
Elkington, D.; Belcher, W. J.; Dastoor, P. C.; Zhou, X. J.
2014-07-01
We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors for salivary glucose.
20. Detection of saliva-range glucose concentrations using organic thin-film transistors
Energy Technology Data Exchange (ETDEWEB)
Elkington, D.; Belcher, W. J.; Dastoor, P. C.; Zhou, X. J. [Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308 (Australia)
2014-07-28
We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors for salivary glucose.
1. High performance Mo adsorbent PZC
Energy Technology Data Exchange (ETDEWEB)
Anon.
1998-10-01
We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)
2. Electronic properties of the n-type PDI8-CN2 organic semiconductor at the interface with SiO2: addressing the role of adsorbed water molecules by means of optical second-harmonic generation
International Nuclear Information System (INIS)
We investigate the interfacial electronic properties of N,N’-bis(n-octyl)-(1,7 and 1,6)-dicyanoperylene-3,4:9,10-bisdicarboximide (PDI8-CN2) organic semiconductor films grown on silicon dioxide (SiO2) by polarization-resolved second harmonic generation optical spectroscopy. The analysis shows a non-uniform distribution of charge carriers in PDI8-CN2, whose spatial profile is affected by hydrophobic passivation of SiO2 surfaces by hexamethyldisilazane. An interpretation model strengthened by photoluminescence analysis is developed, based on the presence of the net charge localized at the SiO2 surface and on consequent charge redistribution in the organic semiconductor. Considerations are expounded suggesting a common and ‘universal’ mechanism for the bias stress effect in p-channel and n-channel organic field-effect transistors, related to proton migration toward SiO2 gate dielectrics. (paper)
3. Positronium chemistry in porous adsorbents
International Nuclear Information System (INIS)
Kinetic studies on the annihilation of orthopositronium in porous adsorbents have been performed using lifetime spectroscopy. The positron source applied was 22Na with 0.2 MBq activity. The adsorbents investigated were silica gels of different particle size and pore structure. The appearance of the long-lived component in the lifetime spectra can be explained by the diffusion of the orthopositronium into the pores affected by the particle size and the pore size of the adsorbent, the coverage on it and the chemical nature of the adsorbate. The long-term aim of the work is to determine and to explain these effects. (author)
4. Microchip electrophoresis with background electrolyte containing polyacrylic acid and high content organic solvent in cyclic olefin copolymer microchips for easily adsorbed dyes.
Science.gov (United States)
Wei, Xuan; Sun, Ping; Yang, Shenghong; Zhao, Lei; Wu, Jing; Li, Fengyun; Pu, Qiaosheng
2016-07-29
Plastic microchips can significantly reduce the fabrication cost but the adsorption of some analytes limits their application. In this work, background electrolyte containing ionic polymer and high content of organic solvent was adopted to eliminate the analyte adsorption and achieve highly efficient separation in microchip electrophoresis. Two dyes, rhodamine 6G (Rh6G) and rhodamine B (RhB) were used as the model analytes. By using methanol as the organic solvent and polyacrylic acid (PAA) as a multifunctional additive, successful separation of the two dyes within 75μm id. microchannels was realized. The role of PAA is multiple, including viscosity regulator, selectivity modifier and active additive for counteracting analyte adsorption on the microchannel surface. The number of theoretical plate of 7.0×10(5)/m was attained within an effective separation distance of 2cm using background electrolyte consisting 80% methanol, 0.36% PAA and 30mmol/L phosphate at pH 5.0. Under optimized conditions, relative standard deviations of Rh6G and RhB detection (n=5) were no more than 1.5% for migration time and 2.0% for peak area, respectively. The limit of detection (S/N=3) was 0.1nmol/L for Rh6G. The proposed technique was applied in the determination of both Rh6G and RhB in chilli powder and lipstick samples with satisfactory recoveries of 81.3-103.7%. PMID:27371017
5. Studies on applications of functional organic-thin-films for lithography on semiconductor device production
International Nuclear Information System (INIS)
This report describes some experimental results of studies in an attempt to contribute to the development of ultra-fine lithography which is used for the manufacture of semiconductor devices with design rule below 0.5 μm, and contains (1) manufacture of the exposure apparatus, (2) establishment of the resist process technology, and (3) preparation of the resist materials. The author designed and manufactured the KrF excimer laser stepper which is supposed to be most promising for practical uses. In the resist processing technology, the water-soluble contrast enhanced lithography (CEL) process was developed and this process has advantages is that high pattern contrast and large focus depth latitude were easily obtained. Finally, for resist materials, use of Langmuir-Blodgett (LB) films was investigated since the LB technique provides the method to prepare extremely thin organic films which are uniform in molecular level, and the reaction mechanism of the LB films of unsaturated compounds under irradiation with high energy beams was elucidated. (author)
6. Natural organic matter interactions with polyamide and polysulfone membranes: Formation of conditioning film
KAUST Repository
Gutierrez, Leonardo
2015-03-31
A conditioning film changes the physicochemical properties of the membrane surface and strongly affects subsequent fouling behavior. Results from this Atomic Force Microscopy study indicate that Natural Organic Matter (NOM) characteristics, membrane surface properties, and solution chemistry are fundamental during conditioning film formation. Repulsive forces were observed between HUM (humic-NOM) and Polyamide (PA) or Polysulfone (PS) membranes during approach in Na+ and Ca2+ solutions. However, repulsive and attractive forces were randomly recorded during BIOP (biopolymer-NOM) approach to both membranes, possibly caused by low electrostatic repulsion, hydrogen bonding, and presence of chemically/physically heterogeneous regions on membrane surfaces. During retracting, Ca2+ ions increased HUM adhesion to PA and PS membrane, indicating cation bridging/complexation as dominant interacting mechanism for this isolate. BIOP adsorption on PS and PA membrane was stronger than HUM under similar solution conditions, where hydrogen bonding would play an important role. Additionally, irrespective of solution conditions, higher adhesion energy was recorded on PS than on PA membrane for both NOM isolates, indicating membrane hydrophobicity as an important interacting factor. Results from this research will advance our understanding of conditioning film formation for NOM isolates and membranes of different physicochemical characteristics.
7. Apple, carrot, and hibiscus edible films containing plant antimicrobials inactivate Salmonella Newport in packaged organic leafy greens
Science.gov (United States)
The increased demand for organic leafy green may raise the risk of foodborne illness outbreaks due to consumption of contaminated produce. Edible films incorporated with natural antimicrobials have the potential to be used as ingredients into organic bagged salads to control contamination from path...
8. Metal-organic chemical vapour deposition of lithium manganese oxide thin films via single solid source precursor
Directory of Open Access Journals (Sweden)
Oyedotun K.O.
2015-12-01
Full Text Available Lithium manganese oxide thin films were deposited on sodalime glass substrates by metal organic chemical vapour deposition (MOCVD technique. The films were prepared by pyrolysis of lithium manganese acetylacetonate precursor at a temperature of 420 °C with a flow rate of 2.5 dm3/min for two-hour deposition period. Rutherford backscattering spectroscopy (RBS, UV-Vis spectrophotometry, X-ray diffraction (XRD spectroscopy, atomic force microscopy (AFM and van der Pauw four point probe method were used for characterizations of the film samples. RBS studies of the films revealed fair thickness of 1112.311 (1015 atoms/cm2 and effective stoichiometric relationship of Li0.47Mn0.27O0.26. The films exhibited relatively high transmission (50 % T in the visible and NIR range, with the bandgap energy of 2.55 eV. Broad and diffused X-ray diffraction patterns obtained showed that the film was amorphous in nature, while microstructural studies indicated dense and uniformly distributed layer across the substrate. Resistivity value of 4.9 Ω·cm was obtained for the thin film. Compared with Mn0.2O0.8 thin film, a significant lattice absorption edge shift was observed in the Li0.47Mn0.27O0.26 film.
9. Thermodynamic study of fatty acids adsorption on different adsorbents
International Nuclear Information System (INIS)
This work has as objective the study about the adsorption behavior of fatty acids (acetic, propionic, and butyric) on activated carbon and on modified and unmodified montmorillonite clays as a function of temperature and initial concentration of the adsorbate, through adsorption isotherms and their thermodynamic parameters (ΔG, ΔH, and ΔS). The activated carbon presented a higher adsorption capacity due to its relatively large surface area, compared to others adsorbents. The polar characteristic of fatty acids decreased with the increase in the length of non-polar hydrocarbon chain, improving the affinity between the activated carbon (non-polar adsorbent) and the acids. The adsorption capacity of modified montmorillonite (polar adsorbent) was favored due to the presence of the organic cation among its layers, which make the surface more hydrophobic and organophilic when compared to the unmodified montmorillonite surface. The amount of fatty acids adsorbed in the adsorbents surface increased with the concentration, at constant temperature, and decreased with the increase of temperature, at constant concentration. The amount of fatty acids adsorbed in the three adsorbents was related to the surface area and polarity of the adsorbent, concentration and solubility of the adsorbate and temperature of the solution. The negative values of ΔG and ΔH showed that the adsorption on activated carbon and on modified and unmodified montmorillonite clays was a spontaneous and an exothermic process. The decrease in the values of ΔG, with the increase of temperature, demonstrated that the adsorption was benefited by the high temperature and the positive values of ΔS showed that the fatty acids molecules were in a more randomic condition in the adsorbed state than in solution. The experimental results obtained at the temperatures of (298, 303, 313, and 323) K showed that experimental data were well represented by the Langmuir and Freundlich isotherms models
10. Electrokinetic investigations of solid/organic liquid dispersions: Effects of temperature treatment of the solid and alkyl chain length of adsorbed amines
Energy Technology Data Exchange (ETDEWEB)
Jada, A.; Siffert, B.; Eleli-Letsango, J. [Centre de Recherches sur la Physico-Chimie des Surfaces Solides 24, avenue du President Kenedy 68200 MULHOUSE (France)
1996-01-01
Zeta potential of two oxides TiO{sub 2} and Al{sub 2}O{sub 3}, dispersed in various organic solvents were measured at room temperature. The inorganic particles were dried at temperatures ranging from 100 to 500{degree}C for several days and were allowed to cool under vacuum just before use. Electrokinetic investigations of TiO{sub 2} particles in n-alkylamine-hexane solutions with various amine chain lengths (C{sub n}H{sub 2n+1}NH{sub 2}, n=1{endash}10) were also done and allowed the determination of the shear plane position in the eventual electric double layer surrounding the solid surface. Furthermore, in order to estimate the thickness {delta} of the electrical double layer surrounding the solid surface, DLVO theory was applied to TiO{sub 2} particles dispersed in n-hexane, in the presence of butylamine. {copyright} {ital 1996 American Institute of Physics.}
11. I. Fundamental Practicum: Temperature Measurements of Falling Droplets, July, 1989. II. Industrial Practicum: Interaction and Effect of Adsorbed Organics on Reference Clays and Reservoir Rock, April, 1988. III. Apprenticeship Practicum: Studies of Group XIII Metal Inclusion Complexes, March, 1987
Science.gov (United States)
Wells, Mark Richard
The temperature of 225 μm decane droplets falling through a hot, quiescent, oxygen -free environment were measured using laser-induced exciplex fluorescence thermometry. The temperature of the droplets was found to increase approximately 0.42^ circC/^circC increase in the environment temperature as the environment temperature was increased to 250^circ C. Less than 10% evaporation of the droplets was observed at the highest environment temperatures. This represents one of the first successful applications of a remote-sensing technique for the temperature determination of droplets in a dynamic system. Industrial practicum. The industrial practicum report, entitled "Interaction and Effect of Adsorbed Organics on Reference Clays and Reservoir Rock," is a discussion of the measurement of the effect adsorbed organic material, especially from crude petroleum, has on the surface area, cation exchange capacity, and zeta potential of reference clay material and reservoir rock. In addition, the energetics of adsorption of a petroleum extract onto several reference clays and reservoir rock were measured using both flow and batch microcalorimetry. These results are very important in evaluating and understanding the wettability of reservoir rock and its impact on the recovery of crude oil from a petroleum reservoir. Apprenticeship practicum. "Studies of Group XIII Metal Inclusion Complexes" investigates the structure and dynamics of liquid inclusion complexes having the general formula (R_4N) (Al_2 Me_6I) cdot (C_6H_6) _{rm x}. ^1H and ^{13}C spin-lattice relaxation times, nuclear Overhauser enhancements, and molecular correlation times were measured as well as diffusion coefficients of the various species in solution. The dynamics of transfer between "guest" and free solvent molecules were measured using a variety of techniques. The inherent structure of liquid inclusion complexes as an ordered medium for homogeneous catalysis was studied using hydrogenation catalyzed by
12. Structural measurements of polymer-fullerene blend films for organic photovoltaics
Science.gov (United States)
Delongchamp, Dean
2011-03-01
Organic photovoltaic (OPV) technology has the potential to greatly lower the cost of solar cell fabrication by enabling ink-based deposition of active layers. In bulk heterojunction (BHJ) OPV devices, the power conversion efficiency critically depends on the distribution of the polymer absorber and the fullerene electron acceptor (e.g., the blend morphology). I will describe measurement methods to probe the structure of OPV devices, with a focus on the morphology of the BHJ layer. For example, the vertical distribution of absorber and electron acceptor in BHJ films follows segregation behavior similar to that of miscible polymer blends. The top (air) interface becomes rich in the polymer absorber, whereas the bottom interface composition depends on the substrate surface energy. Thin film transistors fabricated from BHJs can therefore exhibit ambipolar or hole-only transport depending on the dielectric, because of different interfacial segregation. We extend these results to practical photovoltaic devices by comparing BHJs cast upon hole transport layers that have similar work functions but different surface energies. This study includes the application of variable angle spectroscopic ellipsometry (VASE) to BHJ films, and emphasizes the importance of absorber anisotropy and vertical heterogeneity in the optical model. Additional results will describe the nanometer-scale structure in the BHJ interior. The application of solid-state nuclear magnetic resonance (SS-NMR) can reveal details about the segregation of absorber and acceptor in a BHJ film. Nanoscale BHJ morphology information can also be collected using tomographic transmission electron microscopy (TEM). Together these measurements allow us to reveal a detailed picture of BHJ morphology, explain how the morphology originates from materials and processing choices, and relate the morphology to device performance and stability.
13. Transparent conductive PVP/AgNWs films for flexible organic light emitting diodes by spraying method
Science.gov (United States)
Hu, Jun-tao; Mei, Wen-juan; Ye, Kang-li; Wei, Qing-qing; Hu, Sheng
2016-05-01
In this study, a simple spraying method is used to prepare the transparent conductive films (TCFs) based on Ag nanowires (AgNWs). Polyvinylpyrrolidone (PVP) is introduced to modify the interface of substrate. The transmittance and bending performance are improved by optimizing the number of spraying times and the solution concentration and controlling the annealing time. The spraying times of 20, the concentration of 2 mg/mL and the annealing time of 10 min are chosen to fabricate the PVP/AgNWs films. The transmittance of PVP/AgNWs films is 53.4%—67.9% at 380—780 nm, and the sheet resistance is 30 Ω/□ which is equivalent to that of commercial indium tin oxide (ITO). During cyclic bending tests to 500 cycles with bending radius of 5 mm, the changes of resistivity are negligible. The performance of PVP/AgNW transparent electrodes has little change after being exposed to the normal environment for 1 000 h. The adhesion to polymeric substrate and the ability to endure bending stress in AgNWs network films are both significantly improved by introducing PVP. Spraying method makes AgNWs form a stratified structure on large-area polymer substrates, and the vacuum annealing method is used to weld the AgNWs together at junctions and substrates, which can improve the electrical conductivity. The experimental results indicate that PVP/AgNW transparent electrodes can be used as transparent conductive electrodes in flexible organic light emitting diodes (OLEDs).
14. Fabrication of organically modified oxygen sensing film based on fluorescent quenching
Institute of Scientific and Technical Information of China (English)
XIN LingLing; XIAO LaiLong; ZHAO Li; CHEN Xi; WANG XiaoRu
2007-01-01
An organically modified silicate (ORMOSIL) as a matrix for oxygen-sensitive sensor, in which dimethyldimethoxysilane was selected as an organic modifier in the precursor, is described. The sensing film with tris-(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) as an indicator developed in this paper was characterized by efficient quenching by oxygen. Blue light-emitting diodes ((max ＝ 475 nm) were employed as light excitation source. The linear range of the dissolved oxygen was from 0.5 to 16 (g/mL. The measured RSD was 2%, the response time (t95) was 60 s, and the determination limit was 0.2 (g/mL. A portable and inexpensive luminescence-based sensor was established and applied to the determination of dissolved oxygen in the surface water.
15. Spectroscopic studies of organic-inorganic composite film cured by low energy electron beam
International Nuclear Information System (INIS)
Liquid epoxidized natural rubber acrylate (LENRA) film was reinforced with silica particles formed in-situ via sol gel process. Combination of these two components produces organic-inorganic composites. Tetraethyl orthosilicate (TEOS) was used as precursor material for silica generation. Sol gel reactions was carried out at different concentrations of TEOS i.e. between 10 and 50 phr. The compounds that contain silica were crosslinked by electron beam. Structural properties studies were carried out by Fourier Transform Infrared Spectrometer (FTIR). It was found that miscibility between organic and inorganic components improved with the presence of silanol groups (Si-OH) and polar solvent i.e. THF, via hydrogen bonding formation between siloxane and LENRA. Morphology study by the transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed in-situ generated silica particles were homogenous and well dispersed at any concentrations of TEOS. (author)
16. Flexible Electronics: Integration Processes for Organic and Inorganic Semiconductor-Based Thin-Film Transistors
Directory of Open Access Journals (Sweden)
Fábio F. Vidor
2015-07-01
Full Text Available Flexible and transparent electronics have been studied intensively during the last few decades. The technique establishes the possibility of fabricating innovative products, from flexible displays to radio-frequency identification tags. Typically, large-area polymeric substrates such as polypropylene (PP or polyethylene terephthalate (PET are used, which produces new requirements for the integration processes. A key element for flexible and transparent electronics is the thin-film transistor (TFT, as it is responsible for the driving current in memory cells, digital circuits or organic light-emitting devices (OLEDs. In this paper, we discuss some fundamental concepts of TFT technology. Additionally, we present a comparison between the use of the semiconducting organic small-molecule pentacene and inorganic nanoparticle semiconductors in order to integrate TFTs suitable for flexible electronics. Moreover, a technique for integration with a submicron resolution suitable for glass and foil substrates is presented.
17. Percolation of Carbon Nanoparticles in Poly(3-Hexylthiophene Enhancing Carrier Mobility in Organic Thin Film Transistors
Directory of Open Access Journals (Sweden)
Chang-Hung Lee
2014-01-01
Full Text Available To improve the field-effect mobility of all-inkjet-printed organic thin film transistors (OTFTs, a composite material consisted of carbon nanoparticles (CNPs and poly(3-hexylthiophene (P3HT was reported by using homemade inkjet-printing system. These all-inkjet-printed composite OTFTs represented superior characteristics compared to the all-inkjet-printed pristine P3HT OTFTs. To investigate the enhancement mechanism of the blended materials, the percolation model was established and experimentally verified to illustrate the enhancement of the electrical properties with different blending concentrations. In addition, experimental results of OTFT contact resistances showed that both contact resistance and channel resistance were halved. At the same time, X-ray diffraction measurements, Fourier transform infrared spectra, ultraviolet-visible light, and photoluminescence spectra were also accomplished to clarify the material blending effects. Therefore, this study demonstrates the potential and guideline of carbon-based nanocomposite materials in all-inkjet-printed organic electronics.
18. Sulfometuron incorporation in cationic micelles adsorbed on montmorillonite.
Science.gov (United States)
Mishael, Yael Golda; Undabeytia, Tomas; Rytwo, Giora; Papahadjopoulos-Sternberg, Brigitte; Rubin, Baruch; Nir, Shlomo
2002-05-01
The aim of this study was to understand the interactions between alkylammonium cations present as monomers and micelles and a clay mineral, montmorillonite, to develop slow release formulations of anionic herbicides, such as sulfometuron (SFM) whose leaching in soils is an environmental and economic problem. In the proposed formulation the herbicide is incorporated in positively charged micelles of quaternary amine cations, which in turn adsorb on the negatively charged clay. The adsorption of hexadecyltrimethylammonium (HDTMA) and octadecyltrimethylammonium (ODTMA) on montmorillonite was studied above and below their critical micelle concentrations (CMC). At concentrations above the CMC, the loading exceeded the clay's cation exchange capacity (CEC) and indicated higher affinity of the cation with the longer alkyl chain. An adsorption model could adequately simulate adsorption at concentrations below the CMC, and yield fair predictions for the effect of ionic strength. The model indicated that above the CMC adsorbed micelles contributed significantly to the amount of ODTMA adsorbed. Evidence for adsorption of ODTMA micelles on montmorillonite was provided by X-ray diffraction, freeze-fracture electron microscopy, and dialysis bag measurements. SFM was not adsorbed directly on the clay mineral, and adsorbed at low levels, when the organic cation was adsorbed as monomers. In contrast, a large fraction of SFM adsorbed on the clay mineral when incorporated in micelles that adsorbed on the clay. PMID:11982411
19. Selective sorption of perfluorooctane sulfonate on molecularly imprinted polymer adsorbents
Institute of Scientific and Technical Information of China (English)
Shubo DENG; Danmeng SHUAI; Qiang YU; Jun HUANG; Gang YU
2009-01-01
Perfluorooctane sulfonate (PFOS), as a potential persistent organic pollutant, has been widely detected in water environments, and has become a great concern in recent years. PFOS is very stable and difficult to decompose using conventional techniques. Sorption may be an attractive method to remove it from water. In this study, the molecularly imprinted polymer (MIP) adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate (PFOS) from water. The MIP adsorbents using perfluorooctanoic acid (PFOA) as the template had good imprinting effects and could selectively remove PFOS from aqueous solution. The sorption behaviors including sorption kinetics,isotherms, and effect of pH, salt, and competitive anions were investigated. Experimental results showed that the sorption of PFOS On the MIP adsorbents was very fast, pH-dependent, and highly selective. The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents. The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations, which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface. The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS. The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.
20. Optical and Morphological Studies of Thermally Evaporated PTCDI-C8 Thin Films for Organic Solar Cell Applications
Directory of Open Access Journals (Sweden)
Ronak Rahimi
2013-01-01
Full Text Available PTCDI-C8 due to its relatively high photosensitivity and high electron mobility has attracted much attention in organic semiconductor devices. In this work, thin films of PTCDI-C8 with different thicknesses were deposited on silicon substrates with native silicon dioxide using a vacuum thermal evaporator. Several material characterization techniques have been utilized to evaluate the structure, morphology, and optical properties of these films. Their optical constants (refractive index and extinction coefficient have been extracted from the spectroscopic ellipsometry (SE. X-ray reflectivity (XRR and atomic force microscopy (AFM were employed to determine the morphology and structure as well as the thickness and roughness of the PTCDI-C8 thin films. These films revealed a high degree of structural ordering within the layers. All the experimental measurements were performed under ambient conditions. PTCDI-C8 films have shown to endure ambient condition which allows pots-deposition characterization.
1. Stopping power of fluorides and semiconductor organic films for low-velocity protons
International Nuclear Information System (INIS)
A combined experimental and theoretical study of the energy loss of protons in fluorides and organic films is presented. The measurements were performed in fresh AlF3, LiF, and N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxdiimide (EP-PTCDI) evaporated in situ on self-supported C or Ag foils, covering the very low energy range from 25 keV down to 0.7 keV. The transmission method is used in combination with time-of-flight (TOF) spectrometry. In the case of fluorides with large band gap energies (AlF3 and LiF), the experimental stopping power increases almost linearly with the mean projectile velocity showing a velocity threshold at about 0.1 a.u. These features are well reproduced by a model based on quantum scattering theory that takes into account the velocity distribution and the excitation of the active 2p electrons in the F- anions, and the properties of the electronic bands of the insulators. In the case of the semiconductor organic film with a lower gap, the experimental stopping power increases linearly with the mean projectile velocity without presenting a clear threshold. This trend is also reproduced by the proposed model.
2. Diffusion of metal atoms on organic thin films studied by PEEM
International Nuclear Information System (INIS)
Full text: Recently there has been much interest in organic devices. The stability of metal microstructure deposited on organic films is crucial for these devices of higher integration. In this study, we measured photoelectron emission microscopy (PEEM) images of metals (In, Au, Al) microstructure, deposited onto perylene-3,4,9,10-tetracarboxylic acid-dianhydride (PTCDA) thin films prepared on MoS2 substrate through a mesh (10μm x 10μm square opening, 25μm periodicity). In PEEM experiments, a D2 lamp (hv 2, the PEEM images showed a periodic triangle pattern, although the deposited shape of the In microstructure was square. The triangular shape area was larger than the mesh opening, indicating that In atoms diffuse to three lateral directions. The three directions of diffusion were found to correspond with surface crystal axes of MoS2. Such three directional diffusion was not observed for Au/PTCDA/MoS2, Al/PTCDA/MoS2, In(1 Angstroms)/PTCDA(submonolayer)/MoS2 and In/MoS2. These results suggest that the diffusion originates from (1) strong chemical interaction between PTCDA and In, and (2) the molecular packing structure of PTCDA which depends on substrate surfaces
3. The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers
Science.gov (United States)
Hsu, Yu-Jen
Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by
4. The response of quartz crystals coated with thin fatty acid film to organic gases
CERN Document Server
Jin, C N; Kim, K H; Kwon, Y S
1999-01-01
We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C sub 1 sub 4), palmitic acid (C sub 1 sub 6), stearic acid (C sub 1 sub 8), and arachidic acid (C sub 2 sub 0) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic gases was higher for higher molecular-weight gas, and we found that quar...
5. The influence of a polymeric adhesion layer on gate insulators in organic thin-film-transistors
International Nuclear Information System (INIS)
The electrical characteristics of organic thin-film-transistors (OTFTs) can be improved by inserting an adhesion layer on the gate dielectric prior to the deposition of the organic semiconductor. A polyimide (PI) film was used as polymeric adhesion layer deposited on an inorganic gate insulator such as silicon dioxide (SiO2) or silicon nitride (SiNx), and the adhesion layer was formed by using a vapor deposition polymerization (VDP), instead of a spin-coating process. The molecular ordering of pentacene could be enhanced by using a PI adhesion layer which has a lower surface energy and roughness than SiO2 or SiNx. We also investigated the electrical characteristics of OTFTs for different thickness of the PI adhesion layer. The OTFTs with an adhesion layer attained on on/off ratio of ∼ 106, a threshold voltage of -0.8 ∼ 4 V, and a subthreshold slope of 2.0 ∼ 2.5 V/decade. Especially, a field effect mobility, of about 0.01 cm2/Vs was obtained for bare SiO2 and SiNx, whereas with an adhesion layer, as improved value of 0.1 ∼ 0.4 cm2/Vs was obtained, which depended on the thickness of the PI layer.
6. Bi2O3 nanoparticles encapsulated in surface mounted metal-organic framework thin films
Science.gov (United States)
Guo, Wei; Chen, Zhi; Yang, Chengwu; Neumann, Tobias; Kübel, Christian; Wenzel, Wolfgang; Welle, Alexander; Pfleging, Wilhelm; Shekhah, Osama; Wöll, Christof; Redel, Engelbert
2016-03-01
We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye.We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00532b
7. Preparation and characterization of BiFeO3 thin films by the LPD on OH-functionalized organic SAMs
Institute of Scientific and Technical Information of China (English)
2010-01-01
BiFeO3 (BFO) thin films were grown on OH-functionalized organic self-assembled monolayers (SAMs) via liquid-phase deposition (LPD) method at a temperature below 100°C. The BiFeO3 thin films were induced to synthesize on the OH-functionalized organic OTS monolayers prepared on hydroxylated glass substrate by self-assembling technique. The hydrophilic characteristic of the as-prepared OTS-SAMs was measured by contact angle tester. The crystal phase composition, microstructure and topography of the as-synthesized BFO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and atomic force microscope (AFM), respectively. Results show that compact and homogeneous BFO thin films can be formed on the OH-functionalized SAMs at low temperature.
8. MOLECULAR DYNAMICS SIMULATION OF SELF-ORGANIZED STRUCTURE IN MICRO-PHASE SEPARATION OF NANO-SCALE FILM
Institute of Scientific and Technical Information of China (English)
Dexiang Tang; Wei Ge; Jinghai Li
2004-01-01
Self-organization in thin micro-films has shown potential for the production of microelements with specific structures and functions; however, little is known about its mechanism of formation. A 2-D molecular dynamics (MD)simulation on this process is carried out in this paper for films between two parallel walls (substrates) under different initial conditions. The films consist of two immiscible components (A and B). The simulation results in alternative columns perpendicular to the walls, which are rich either in A or in B molecules, respectively, apparently owing to their different interactions with the walls. The characteristic breadths of the columns depend on the distance between the two walls. By providing microscopic details of the self-organization processes and the resulted structures, MD simulation proves itself as a unique way for analyzing the dynamics of thin films.
9. The influence of sediment particle size on the properties of adsorbed dissolved organic matter in the Yangtze Estuary and its interactions with As/Sb.
Science.gov (United States)
Wang, Ying; Zhang, Manman; Zhang, Di; Shen, Zhenyao
2016-04-15
The characteristics of dissolved organic matter (DOM) extracted from sediments with four particle sizes (200μm) in the Yangtze Estuary were compared. The differences in their binding capacities for individual fluorescent components with As/Sb were studied using fluorescence-quenching titrations combined with excitation-emission matrix (EEM) spectra. The results indicated that the particle size influenced the quality and quantity of extracted DOM. With increasing particle size, the extracted DOM content, value of UV280 and acidic functional group content of the DOM decreased. Three protein-like components (C2, C3 and C4) and one humic-like component (C1) were identified using the parallel factor analysis (PARAFAC) model. Wherein, protein-like material dominated in DOM on different particle-size fractions and possessed a stronger complex capacity with As/Sb. A significant positive correlation between the complexation capacity of extracted DOM from samples, as well as with the acidic functional group content, was observed. PMID:26965093
10. Structural features of resorcinol–formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics
Energy Technology Data Exchange (ETDEWEB)
Gun’ko, Vladimir M., E-mail: [email protected] [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Turov, Vladimir V. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Leboda, Roman; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine)
2013-10-15
Products of resorcinol–formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (C{sub w} = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if C{sub w} = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp{sup 3} C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.
11. Structural features of resorcinol-formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics
Science.gov (United States)
Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Turov, Vladimir V.; Leboda, Roman; Skubiszewska-Zięba, Jadwiga; Urubkov, Iliya V.
2013-10-01
Products of resorcinol-formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (Cw = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if Cw = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp3 C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.
12. Identification of urushi coated films taken from ancient Buddha images by using PIXE, FT-IR, and organic elemental analysis
International Nuclear Information System (INIS)
Six types of samples including urushi, urushi tree and black coating films taken from ancient Buddha images were examined by analyses of PIXE, organic element and FT-IR to identify with urushi or another material. Based on the results of three analytical experiments above mentioned, the coating materials aging over hundreds of years were identified with weathered urushi films mixed with other material. Further investigation may reveal the urushi coating techniques used in the past. (author)
13. Identification of urushi coated films taken from ancient Buddha images by using PIXE, FT-IR, and organic elemental analysis
Energy Technology Data Exchange (ETDEWEB)
Kagemori, N.; Umemura, K.; Yoshimura, T.; Inoue, M.; Kawai, S. [Wood Research Institute, Kyoto Univ., Uji, Kyoto (Japan); Yano, K. [Tokyo National University of Fine Arts and Music, Uenokouen, Tokyo (Japan); Sera, K. [Cyclotron Research Center, Iwate Medical Univ., Takizawa, Iwate (Japan); Futatsugawa, S. [Nishina Memorial Cyclotron Center, Japan Radioisotope Association, Takizawa, Iwate (Japan); Nakamura, Y. [Kyoto National Museum, Higashiyama, Kyoto (Japan)
1999-07-01
Six types of samples including urushi, urushi tree and black coating films taken from ancient Buddha images were examined by analyses of PIXE, organic element and FT-IR to identify with urushi or another material. Based on the results of three analytical experiments above mentioned, the coating materials aging over hundreds of years were identified with weathered urushi films mixed with other material. Further investigation may reveal the urushi coating techniques used in the past. (author)
14. Syntheses of Amine Type Adsorbents with Emulsion Graft Polymerization of Glycidyl Methacrylate
International Nuclear Information System (INIS)
Radiation-induced graft polymerization is attractive technique for preparing metal-ion adsorbents. This technique enables to introduce aiming function onto trunk polymers such as polymeric films, fibers, nonwoven fabric, and hollow fibers. The reactive monomer of glycidyl methacrylate (GMA) has been widely used for the syntheses of metal-ion adsorbents. This is because the GMA contains an epoxy group which can react easily with amine derivatives. Therefore, GMA-grafted polymer can be converted to various kinds of metal-ions adsorbents. Generally, GMA can be grafted by using organic solvent such as methanol and dimethyl sulfoxide. We found that the emulsion of GMA was available for effective grafting. In this case, the solvent is water so that the emulsion graft polymerization promises to be the green chemistry. In the present study, the GMA was grafted onto polyethylene fiber (PE fiber) in the emulsion system. Polyoxyethylene sorbitan monolaurate (Tween 20) was used as a surfactant to prepare the micelles of GMA in water. Graft polymerization of GMA micelles was investigated on the conditions of the total dose of irradiation, the monomer concentration, the surfactant concentration, the reaction time, and the reaction temperature
15. In situ preparation of biomimetic thin films and their surface-shielding effect for organisms in high vacuum.
Directory of Open Access Journals (Sweden)
Hiroshi Suzuki
Full Text Available Self-standing biocompatible films have yet to be prepared by physical or chemical vapor deposition assisted by plasma polymerization because gaseous monomers have thus far been used to create only polymer membranes. Using a nongaseous monomer, we previously found a simple fabrication method for a free-standing thin film prepared from solution by plasma polymerization, and a nano-suit made by polyoxyethylene (20 sorbitan monolaurate can render multicellular organisms highly tolerant to high vacuum. Here we report thin films prepared by plasma polymerization from various monomer solutions. The films had a flat surface at the irradiated site and were similar to films produced by vapor deposition of gaseous monomers. However, they also exhibited unique characteristics, such as a pinhole-free surface, transparency, solvent stability, flexibility, and a unique out-of-plane molecular density gradient from the irradiated to the unirradiated surface of the film. Additionally, covering mosquito larvae with the films protected the shape of the organism and kept them alive under the high vacuum conditions in a field emission-scanning electron microscope. Our method will be useful for numerous applications, particularly in the biological sciences.
16. One-step growth of lanthanoid metal-organic framework (MOF) films under solvothermal conditions for temperature sensing.
Science.gov (United States)
Liu, Xue; Fu, Wentian; Bouwman, Elisabeth
2016-05-25
A one-step direct solvothermal synthesis of an Ln metal-organic framework (MOF) film is reported. The LnHL (Ln = Tb and Gd) films that were deposited on a Gd2O3 subtrate are continuous and smooth. The Gd0.9Tb0.1HL film can be used as a ratiometric thermometer, showing good linear behaviour in the temperature range of 110-250 K with a sensitivity up to 0.8% K(-1). PMID:27147478
17. Molecular beam deposition and polymerization of parylene-N ultrathin films: Effective buffers in organic light emitting diodes
International Nuclear Information System (INIS)
Highlights: • Parylene-N (PPXN) films prepared by using a home-made Knudsen Cell were identified and characterized. • 1 nm PPXN thin films were inserted at different locations in the hole transport layers of organic light emitting diodes. • For an optimized PPXN inserted organic light emitting diodes, current efficiency improvement of 11% was achieved. • The device current efficiency improvement and the current density variation under operation were discussed. - Abstract: Ultrathin Parylene-N (PPXN) films were prepared by using a home-made Knudsen Cell (KC). The PPXN films were identified by infrared (IR) spectra. The morphology and insulativity of PPXN films were measured by atomic force microscope (AFM) and current density versus voltage (j–V) characteristics. Well controlled 1-nm-thick PPXN thin films were inserted at different locations in the N′-bis(naphthalene-1-yl)-N, N′-bis(phenyl) benzidine (NPB) layers of organic light emitting diodes (OLEDs) with the structure of ITO/NPB/tris (8-hydroxyquinolato) aluminum (Alq3)/LiF/Al. For an optimized PPXN inserted structure, current efficiency of 6.27 cd/A was achieved, 11% higher than the 5.64 cd/A of the control one with 1-nm-thick PPXN buffer inserted at the anode interface. The device current efficiency improvement is due to the electron blocking of PPXN buffers, and the current density variation of devices under operation was explained by tunneling barrier reduction
18. In situ intercalation dynamics in inorganic-organic layered perovskite thin films.
Science.gov (United States)
Ahmad, Shahab; Kanaujia, Pawan K; Niu, Wendy; Baumberg, Jeremy J; Vijaya Prakash, G
2014-07-01
The properties of layered inorganic semiconductors can be manipulated by the insertion of foreign molecular species via a process known as intercalation. In the present study, we investigate the phenomenon of organic moiety (R-NH3I) intercalation in layered metal-halide (PbI2)-based inorganic semiconductors, leading to the formation of inorganic-organic (IO) perovskites [(R-NH3)2PbI4]. During this intercalation strong resonant exciton optical transitions are created, enabling study of the dynamics of this process. Simultaneous in situ photoluminescence (PL) and transmission measurements are used to track the structural and exciton evolution. On the basis of the experimental observations, a model is proposed which explains the process of IO perovskite formation during intercalation of the organic moiety through the inorganic semiconductor layers. The interplay between precursor film thickness and organic solution concentration/solvent highlights the role of van der Waals interactions between the layers, as well as the need for maintaining stoichiometry during intercalation. Nucleation and growth occurring during intercalation matches a Johnson-Mehl-Avrami-Kolmogorov model, with results fitting both ideal and nonideal cases. PMID:24905435
19. In Situ Intercalation Dynamics in Inorganic–Organic Layered Perovskite Thin Films
Science.gov (United States)
2014-01-01
The properties of layered inorganic semiconductors can be manipulated by the insertion of foreign molecular species via a process known as intercalation. In the present study, we investigate the phenomenon of organic moiety (R-NH3I) intercalation in layered metal-halide (PbI2)-based inorganic semiconductors, leading to the formation of inorganic–organic (IO) perovskites [(R-NH3)2PbI4]. During this intercalation strong resonant exciton optical transitions are created, enabling study of the dynamics of this process. Simultaneous in situ photoluminescence (PL) and transmission measurements are used to track the structural and exciton evolution. On the basis of the experimental observations, a model is proposed which explains the process of IO perovskite formation during intercalation of the organic moiety through the inorganic semiconductor layers. The interplay between precursor film thickness and organic solution concentration/solvent highlights the role of van der Waals interactions between the layers, as well as the need for maintaining stoichiometry during intercalation. Nucleation and growth occurring during intercalation matches a Johnson–Mehl–Avrami–Kolmogorov model, with results fitting both ideal and nonideal cases. PMID:24905435
20. Electrochemical fabrication of copper-containing metal-organic framework films as amperometric detectors for bromate determination.
Science.gov (United States)
Shi, Erbin; Zou, Xiaoqin; Liu, Jia; Lin, Huiming; Zhang, Feng; Shi, Shaoxuan; Liu, Fenghua; Zhu, Guangshan; Qu, Fengyu
2016-05-01
A facile electrochemical plating strategy has been employed to prepare the electroactive metal-organic framework film (NENU-3) onto a copper electrode in the acid electrolyte containing 1,3,5-benzenetricarboxylic acid (H3BTC) and phosphotungstic acid (PTA). The as-made NENU-3 films have been characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses (TGA). These analyses indicate that NENU-3 films have high phase purity and high stability. Further, different electrochemical techniques are utilized for measuring the electrochemical behaviors of the NENU-3 film electrodes. Accordingly, the kinetic parameters of a NENU-3 film electrode towards the electrocatalytic reduction of bromate are obtained, including the electron transfer coefficient (α), the catalytic rate constant (ks), and the diffusion coefficient (D). The film electrodes present excellent electrocatalytic ability for the bromate reduction, and can be used successfully for the amperometric detection of bromate. Under the optimized conditions, the proposed sensor exhibits a wide linear range (0.05-72.74 mM) and a lower detection limit (12 μM) measured by chronoamperometry (CA). Moreover, the films possess high electrochemical stability and strong anti-interference capability in the bromate detection process. It has been demonstrated that the electrochemical plating method reported here offers a reliable and efficient way to fabricate MOF films on conductive substrates for bromate detection. PMID:27054956
CERN Document Server
Lewis, S P; Lewis, Steven P.; Rappe, Andrew M.
1996-01-01
The vibrational properties of carbon monoxide adsorbed to the copper (100) surface are explored within density functional theory. Atoms of the substrate and adsorbate are treated on an equal footing in order to examine the effect of substrate--adsorbate coupling. This coupling is found to have a significant effect on the vibrational modes, particularly the in-plane frustrated translation, which mixes strongly with substrate phonons and broadens into a resonance. The predicted lifetime due to this harmonic decay mechanism is in excellent quantitative agreement with experiment.
2. Sub-micron phase coexistence in small-molecule organic thin films revealed by infrared nano-imaging
Science.gov (United States)
Westermeier, Christian; Cernescu, Adrian; Amarie, Sergiu; Liewald, Clemens; Keilmann, Fritz; Nickel, Bert
2014-06-01
Controlling the domain size and degree of crystallization in organic films is highly important for electronic applications such as organic photovoltaics, but suitable nanoscale mapping is very difficult. Here we apply infrared-spectroscopic nano-imaging to directly determine the local crystallinity of organic thin films with 20-nm resolution. We find that state-of-the-art pentacene films (grown on SiO2 at elevated temperature) are structurally not homogeneous but exhibit two interpenetrating phases at sub-micrometre scale, documented by a shifted vibrational resonance. We observe bulk-phase nucleation of distinct ellipsoidal shape within the dominant pentacene thin-film phase and also further growth during storage. A faint topographical contrast as well as X-ray analysis corroborates our interpretation. As bulk-phase nucleation obstructs carrier percolation paths within the thin-film phase, hitherto uncontrolled structural inhomogeneity might have caused conflicting reports about pentacene carrier mobility. Infrared-spectroscopic nano-imaging of nanoscale polymorphism should have many applications ranging from organic nanocomposites to geologic minerals.
3. Nanostructured films of inorganic-organic hybrid materials for application in photovoltaics; Nanostrukturierte Filme aus anorganisch-organischen Hybridmaterialien fuer die Photovoltaik
Energy Technology Data Exchange (ETDEWEB)
Perlich, Jan
2009-06-25
Nanostructured thin films of crystalline TiO{sub 2} for applications in photovoltaics were studied. The fabrication of the thin films is based on a hybrid approach. The anorganic metal oxide prepared via a sol-gel synthesis is structurated by the template properties of the applied organic block-copolymer. Via the film epitaxy by means of centrifugal coating first hybrid films (polymer-nanocomposite films) were fabricated, which were changed by calcination into crystalline TiO{sub 2} films with taylored morphology. The successful development of novel preparation approaches to the adaption to consisting conditions in the application field of photovoltaics contains a route to the fine-tuning of the morphology as well as the fabrication of hierarchical morphologies in different configurations. The structural study of the single nanostructurated TiO{sub 2} films up to the functional multilayer arrangement as photovoltaic demonstration cell was performed with conventionally imaging methods, as for instance scanning force microscopy and electron microscopy as well as the special small-angle X-ray scattering method under rigid incident angle (GISAXS). [German] Es wurden nanostrukturierte duenne Filme aus kristallinem TiO{sub 2} fuer Anwendungen in der Photovoltaik untersucht. Die Herstellung der duennen Filme basiert auf einem Hybridansatz. Das ueber eine Sol-Gel-Synthese bereitgestellte anorganische Metalloxid wird durch die Template-Eigenschaften des eingesetzten organischen Block-Copolymers strukturiert. Ueber die Filmaufbringung mittels Schleuderbeschichtung wurden zunaechst Hybridfilme (Polymer-Nanokompositfilme) hergestellt, die durch Kalzinierung in kristalline TiO{sub 2}-Filme mit massgeschneiderter Morphologie umgewandelt werden. Die erfolgreiche Entwicklung von neuartigen Praeparationsansaetzen zur Adaption an bestehende Gegebenheiten im Anwendungsgebiet der Photovoltaik beinhaltet eine Route zur Feineinstellung der Morphologie sowie die Herstellung von
4. Photocatalytic hydrogen generation with simultaneous organic degradation by a visible light-driven CdS/ZnS film catalyst
International Nuclear Information System (INIS)
Highlights: • CdS/ZnS/Ru film catalyst is able to produce H2 under visible light. • The photocatalyst is capable of both H2 production and organic degradation. • ZnS layer improves the photoreactivity and stability of the CdS film. • CdS/ZnS/Ru in formic acid produces 123 mmol H2 and removes 1.9 g COD/m2-h. -- Abstract: A layered CdS/ZnS catalyst film was synthesized on glass using the stepped chemical bath deposition method. The film catalyst was shown as visible light-driven photocatalyst capable of producing H2 under visible light. The ZnS outer layer helped suppress the recombination of photo-generated electron–hole pairs on the CdS base layer, leading to faster H2 generation. The use of the ZnS layer also greatly improved the stability of the catalyst film and prevented the leaching of Cd2+ from the CdS layer. Deposition of Ru on the catalyst film further increased its photoreactivity for H2 production. The photocatalyst was effective in H2 production together with the degradation of model organic substances, such as formic acid, methanol, and ethanol. The greatest H2 production rates were achieved using the CdS/ZnS/Ru film in the formic acid solution at 123 μmol/m2-h under visible light and 135 mmol/m2-h under the simulated solar light. The corresponding theoretical reduction rates of chemical oxygen demand (COD) were 1.9 and 2.1 g/m2-h, respectively. As the multilayer CdS/ZnS/Ru film catalyst can be easily separated from water, it has a great potential for simultaneous photocatalytic hydrogen generation and organic wastewater treatment using solar energy
5. THE USE OF LOW COST ADSORBENTS FOR PURIFICATION WASTEWATER
OpenAIRE
Višekruna, Antonija; Štrkalj, Anita; Marinić Pajc, Ljiljana
2011-01-01
Adsorption is one of the effective methods of advanced wastewater treatment, which industries employ to reduce hazardous organic and inorganic wastes in effluents. The use of low cost adsorbent has been investigated as a replacement for current costly methods of removing toxic substances from wastewater. In this article, the use of low cost adsorbents for the removal of toxic substances from wastewater has been reviewed.
6. Fabrication of single-phase ε-GaSe films on Si(100) substrate by metal organic chemical vapor deposition
International Nuclear Information System (INIS)
Single-phase ε-gallium selenide (GaSe) films were fabricated on Si(100) substrate by metal organic chemical vapor deposition using dual-source precursors: triethylgallium (TEG) and hydrogen selenide (H2Se) with the flow ratio of [H2Se]/[TEG] being maintained at 1.2. In particular, an arsine (AsH3) flow was introduced to the Si substrate before the film deposition to induce an arsenic (As)-passivation effect on the substrate. The crystalline structure of GaSe films prepared was analyzed using X-ray diffraction and the surface morphology of them was characterized by scanning electron microscopy. It was found that the film quality could be improved by the As-passivation effect. The optical properties of the films were studied by temperature dependent photoluminescence (PL) measurements. PL spectra obtained with different distributions and intensities favored for resolving the superior material quality of the films produced on the substrate with As-passivation compared to those produced on the substrate without As-passivation. The former was dominated by the excitonic emissions for the whole temperature range of 20–300 K examined, while the latter was initially dominated by the defect-related emission at 1.907 eV for a low-temperature range ≦ 80 K and then became dominated by the weak excitonic emission band instead. The ε modification of GaSe films prepared was further recognized by the Raman scattering measurements conducted at room temperature. - Highlights: • Gallium selenide (GaSe) layered structures are fabricated on Si(100) substrate. • Metal–organic chemical vapor deposition is used for film fabrication. • Arsenic-passivation effects of Si substrate on the GaSe film quality are analyzed. • Photoluminescence measurements of GaSe polycrystals are reported
7. Preparation of Composited Graphene/PEDOT:PSS Film for Its Possible Application in Graphene-based Organic Solar Cells
Institute of Scientific and Technical Information of China (English)
YU Yue; LI Meicheng; CHU Lihua; YU Hakki; Wodtke A M; ZHAO Yan; ZHANG Zhongmo
2015-01-01
The interface between graphene and organic layers is a key factor responsible for the performance of gra-phene-based organic solar cells (OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film . Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited gra-phene/PEDOT:PSS film on graphene-based OSCs.
8. Zeolites as alcohol adsorbents from aqueous solutions
Directory of Open Access Journals (Sweden)
Cekova Blagica
2006-01-01
Full Text Available The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.
9. The effect of dissolved organic carbon on bacterial adhesion to conditioning films adsorbed on glass from natural seawater collected during different seasons
NARCIS (Netherlands)
Bakker, D.P.; Klijnstra, J.W.; Busscher, H.J.; Mei, H.C. van der
2003-01-01
Adhesion of three marine bacterial strains, i.e. Marinobacter hydrocarbonoclasticus, Psychrobacter sp. and Halomonas pacifica with different cell surface hydrophobicities was measured on glass in a stagnation point flow chamber. Prior to bacterial adhesion, the glass surface was conditioned for 1 h
10. The effect of dissolved organic carbon on bacterial adhesion to conditioning films adsorbed on glass from natural seawater collected during different seasons
NARCIS (Netherlands)
Bakker, DP; Klijnstra, JW; Busscher, HJ; van der Mei, HC
2003-01-01
Adhesion of three marine bacterial strains, i.e. Marinobacter hydrocarbonoclasticus , Psychrobacter sp. and Halomonas pacifica with different cell surface hydrophobicities was measured on glass in a stagnation point flow chamber. Prior to bacterial adhesion, the glass surface was conditioned for 1 h
11. Poly(3-hexylthiophene) films by electrospray deposition for crystalline silicon/organic hybrid junction solar cells
Energy Technology Data Exchange (ETDEWEB)
Hiate, Taiga; Miyauchi, Naoto; Tang, Zeguo; Ishikawa, Ryo; Ueno, Keiji; Shirai, Hajime [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura, Saitama 858-3676 (Japan)
2012-10-15
The electrospray deposition (ESD) of poly(3-hexylthiophene) (P3HT) and conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) on P3HT for use in crystalline silicon/organic hybrid heterojunction solar cells on CZ crystalline silicon (c-Si) (100) wafer was investigated using real-time characterization by spectroscopic ellipsometry (SE). In contrast to the nonuniform deposition of products frequently obtained by conventional spin-coating, a uniform deposition of P3HT and PEDOT:PSS films were achieved on flat and textured hydrophobic c-Si(100) wafers by adjusting the deposition conditions. The c-Si/P3HT/PEDOT:PSS heterojunction solar cells exhibited efficiencies of 4.1 and 6.3% on flat and textured c-Si(100) wafers, respectively. These findings suggest that ESD is a promising method for the uniform deposition of P3HT and PEDOT:PSS films on flat and textured hydrophobic substrates. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
12. Photo-induced halide redistribution in organic-inorganic perovskite films.
Science.gov (United States)
deQuilettes, Dane W; Zhang, Wei; Burlakov, Victor M; Graham, Daniel J; Leijtens, Tomas; Osherov, Anna; Bulović, Vladimir; Snaith, Henry J; Ginger, David S; Stranks, Samuel D
2016-01-01
Organic-inorganic perovskites such as CH3NH3PbI3 are promising materials for a variety of optoelectronic applications, with certified power conversion efficiencies in solar cells already exceeding 21%. Nevertheless, state-of-the-art films still contain performance-limiting non-radiative recombination sites and exhibit a range of complex dynamic phenomena under illumination that remain poorly understood. Here we use a unique combination of confocal photoluminescence (PL) microscopy and chemical imaging to correlate the local changes in photophysics with composition in CH3NH3PbI3 films under illumination. We demonstrate that the photo-induced 'brightening' of the perovskite PL can be attributed to an order-of-magnitude reduction in trap state density. By imaging the same regions with time-of-flight secondary-ion-mass spectrometry, we correlate this photobrightening with a net migration of iodine. Our work provides visual evidence for photo-induced halide migration in triiodide perovskites and reveals the complex interplay between charge carrier populations, electronic traps and mobile halides that collectively impact optoelectronic performance. PMID:27216703
13. Photo-induced halide redistribution in organic-inorganic perovskite films
Science.gov (United States)
Dequilettes, Dane W.; Zhang, Wei; Burlakov, Victor M.; Graham, Daniel J.; Leijtens, Tomas; Osherov, Anna; Bulović, Vladimir; Snaith, Henry J.; Ginger, David S.; Stranks, Samuel D.
2016-05-01
Organic-inorganic perovskites such as CH3NH3PbI3 are promising materials for a variety of optoelectronic applications, with certified power conversion efficiencies in solar cells already exceeding 21%. Nevertheless, state-of-the-art films still contain performance-limiting non-radiative recombination sites and exhibit a range of complex dynamic phenomena under illumination that remain poorly understood. Here we use a unique combination of confocal photoluminescence (PL) microscopy and chemical imaging to correlate the local changes in photophysics with composition in CH3NH3PbI3 films under illumination. We demonstrate that the photo-induced brightening' of the perovskite PL can be attributed to an order-of-magnitude reduction in trap state density. By imaging the same regions with time-of-flight secondary-ion-mass spectrometry, we correlate this photobrightening with a net migration of iodine. Our work provides visual evidence for photo-induced halide migration in triiodide perovskites and reveals the complex interplay between charge carrier populations, electronic traps and mobile halides that collectively impact optoelectronic performance.
14. Self-organized films from cellulose I Nanofibrils using the layer-by-layer technique.
Science.gov (United States)
Aulin, Christian; Johansson, Erik; Wågberg, Lars; Lindström, Tom
2010-04-12
The possibility of forming self-organized films using only charge-stabilized dispersions of cellulose I nanofibrils with opposite charges is presented, that is, the multilayers were composed solely of anionically and cationically modified microfibrillated cellulose (MFC) with a low degree of substitution. The build-up behavior and the properties of the layer-by-layer (LbL)-constructed films were studied using a quartz crystal microbalance with dissipation (QCM-D) and stagnation point adsorption reflectometry (SPAR). The adsorption behavior of cationic/anionic MFC was compared with that of polyethyleneimine (PEI)/anionic MFC. The water contents of five bilayers of cationic/anionic MFC and PEI/anionic MFC were approximately 70 and 50%, respectively. The MFC surface coverage was studied by atomic force microscopy (AFM) measurements, which clearly showed a more dense fibrillar structure in the five bilayer PEI/anionic MFC than in the five bilayer cationic/anionic MFC. The forces between the cellulose-based multilayers were examined using the AFM colloidal probe technique. The forces on approach were characterized by a combination of electrostatic and steric repulsion. The wet adhesive forces were very long-range and were characterized by multiple adhesive events. Surfaces covered by PEI/anionic MFC multilayers required more energy to be separated than surfaces covered by cationic/anionic MFC multilayers. PMID:20196583
15. Light-induced processes on atoms and clusters confined in nanoporous silica and organic films
Science.gov (United States)
Moi, L.; Burchianti, A.; Bogi, A.; Marinelli, C.; Maibohm, C.; Mariotti, E.
2007-03-01
The study of light induced processes on atoms and nanoparticles confined in organic films or in dielectric structures is motivated both by fundamental interest and applications in optics and photonics. Depending on the light intensity and frequency and the kind of confinement, different processes can be activated. Among them photodesorption processes have a key role. Non thermal light induced atomic desorption has been observed from siloxane and paraffin films previously exposed to alkali vapors. This effect has been extensively investigated and used both to develop photo-atom sources and to load magneto-optical traps. Recently we observed huge photodesorption of alkali atoms embedded in nanoporous silica. In this case the atomic photodesorption causes, by properly tuning the light frequency, either formation or evaporation of clusters inside the silica matrix. Green-blue light desorbs isolated adatoms from the glass surface eventually producing clusters, whereas red-near infrared (NIR) light causes cluster evaporation due to direct excitation of surface plasmon oscillations. Green-blue light induces cluster formation taking advantage of the dense atomic vapor, which diffuses through the glass nano-cavities. Both processes are reversible and even visible to the naked eye. By alternatively illuminating the porous glass sample with blue-green and red-NIR light we demonstrate that the glass remembers the illumination sequences behaving as an effective rereadable and rewritable optical medium.
16. In situ vibrational spectroscopy of thin organic films confined at the solid-solid interface
CERN Document Server
Haydock, S A
2002-01-01
Raman scattering was used to study thin films, of hexadecane, octamethyltetrasiloxane (OMCTS), 1-undecanol and Langmuir-Blodgett (LB) monolayers consisting of zinc stearate, zinc arachidate and zinc behenate, all at the solid-solid interface. This thesis contains the first unenhanced Raman spectrum of an organic monolayer confined in the contact between two solid surfaces. The LB monolayers were also investigated with sum-frequency spectroscopy in order that comparisons could be made between results from the two techniques. Thin films were confined between an optical prism and an optical lens at pressures ranging from 30 MPa to 200 MPa. I have shown that the deposited LB monolayers were conformationally ordered and that this high degree of order was retained at applied pressures of up to 200 MPa. However, the application of pressure caused the hydrocarbon chains to tilt from the surface normal. The changes observed in the overall intensity of the Raman spectra on formation of the solid-solid contact can be ex...
17. Efficiency of photodesorption of Rb atoms collected on polymer organic film in vapor-cell
CERN Document Server
Atutov, Sergey N; Chubakov, Pavel A; Plekhanov, Alexander I
2010-01-01
The efficiency of photodesorption of Rb atoms previously collected on polymer organic film has been studied in detail. This study was carried out in a glass cell of which the inner surface was covered with (poly)dimethylsiloxane (PDMS) film and illuminated by a photographic flash lamp. The desorption dynamic of the Rb atoms density in the cell caused by the illumination was studied using an Rb resonance lamp as a source of probing light. It was determined that about 25 percent of the total Rb atoms embedded on the cell walls can be desorbed by single flash from the lamp and almost 50 percent are desorbed by a sequence of several light pulses. Our result might help to construct an efficient light-driven source of atoms for a new type magneto optical trap for atoms in extremely low vapor density or very weak atomic flux of such artificial alkaline atoms as Francium. We believe that the collection and photodesorption of particles could be used for the development of sensors for the trace detection of various ele...
18. Impedimetric and amperometric bifunctional glucose biosensor based on hybrid organic-inorganic thin films.
Science.gov (United States)
Wang, Huihui; Ohnuki, Hitoshi; Endo, Hideaki; Izumi, Mitsuru
2015-02-01
A novel glucose biosensor with an immobilized mediator was studied using electrochemical impedance spectroscopy (EIS) and amperometry measurements. The biosensor has a characteristic ultrathin form and is composed of a self-assembled monolayer anchoring glucose oxidase (GOx) covered with Langmuir-Blodgett (LB) films of Prussian blue (PB). The immobilized PB in the LB films acts as a mediator and enables the biosensor to work under a low potential (0.0V vs. Ag/AgCl). In the EIS measurements, a dramatic decrease in charge transfer resistance (Rct) was observed with sequential addition of glucose, which can be attributed to enzymatic activity. The linearity of the biosensor response was observed by the variation of the sensor response (1/Rct) as a function of glucose concentration in the range 0 to 25mM. The sensor also showed linear amperometric response below 130mM glucose. The organic-inorganic system of GOx and PB nanoclusters demonstrated bifunctional sensing action, both amperometry and EIS modes, as well as long sensing stability for 4 days. PMID:25014167
19. Inverted organic light-emitting diodes using different transparent conductive oxide films as a cathode
Science.gov (United States)
Takada, Makoto; Kobayashi, Takashi; Nagase, Takashi; Naito, Hiroyoshi
2016-03-01
We report on poly(dioctylfluorene-alt-benzothiadiazole) (F8BT) based inverted organic light-emitting diodes (iOLEDs) using commercially available transparent conductive oxide (TCO) films as a cathode, indium tin oxide (ITO), Ga doped ZnO (GZO), and Al doped ZnO (AZO). The ITO, GZO, and AZO glasses work as an electron-injecting layer (EIL) and cathode. The device configuration that we prepared is ITO, GZO, or AZO/F8BT/MoO3/Au. The device characteristics of these iOLEDs are almost comparable to those of conventional iOLEDs with ZnO films prepared by spray pyrolysis as an EIL, indicating that the electron injection properties of ITO, GZO, or AZO as a cathode are similar to those of ZnO layer in conventional iOLEDs. These results demonstrate the low-cost fabrication of iOLEDs utilizing commercially available TCO glasses as a cathode without deposition of ZnO layers on ITO glass.
20. Flexible suspended gate organic thin-film transistors for ultra-sensitive pressure detection
Science.gov (United States)
Zang, Yaping; Zhang, Fengjiao; Huang, Dazhen; Gao, Xike; di, Chong-An; Zhu, Daoben
2015-03-01
The utilization of organic devices as pressure-sensing elements in artificial intelligence and healthcare applications represents a fascinating opportunity for the next-generation electronic products. To satisfy the critical requirements of these promising applications, the low-cost construction of large-area ultra-sensitive organic pressure devices with outstanding flexibility is highly desired. Here we present flexible suspended gate organic thin-film transistors (SGOTFTs) as a model platform that enables ultra-sensitive pressure detection. More importantly, the unique device geometry of SGOTFTs allows the fine-tuning of their sensitivity by the suspended gate. An unprecedented sensitivity of 192 kPa-1, a low limit-of-detection pressure of <0.5 Pa and a short response time of 10 ms were successfully realized, allowing the real-time detection of acoustic waves. These excellent sensing properties of SGOTFTs, together with their advantages of facile large-area fabrication and versatility in detecting various pressure signals, make SGOTFTs a powerful strategy for spatial pressure mapping in practical applications.
1. Sensitivity of the threshold voltage of organic thin-film transistors to light and water
Energy Technology Data Exchange (ETDEWEB)
Feng, Cong; Marinov, Ognian; Deen, M. Jamal; Selvaganapathy, Ponnambalam Ravi [McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1 (Canada); Wu, Yiliang [Xerox Research Centre, 2660 Speakman Dr., Mississauga, Ontario L5K 2L1 (Canada)
2015-05-14
Analyses of extensive experiments with organic thin-film transistors (OTFTs) indicate that the threshold voltage V{sub T} of an OTFT has a temporal differential sensitivity. In particular, V{sub T} changes initially by changing the light illumination intensity or making/removing a contact of water with the organic semiconductor. Keeping the conditions stationary, then the initial shift of V{sub T} diminishes, since the time dependence of V{sub T} gradually recovers the OTFT to the state before applying the change in the environmental conditions. While still causing a differential and time-variant shift of V{sub T}, the deionized water does not have a dramatic impact on OTFTs that use the polymer DKPP-βT (diketopyrrolopyrrole β-unsubstituted quaterthiophene) as the active semiconductor material. Observations for the impact of water are made from experiments with an OTFT that has a microfluidic channel on the top the electrical channel, with the water in the microfluidic channel in direct contact with the electrical channel of the OTFT. This arrangement of electrical and microfluidic channels is a novel structure of the microfluidic OTFT, suitable for sensing applications of liquid analytes by means of organic electronics.
2. Flexible All-organic, All-solution Processed Thin Film Transistor Array with Ultrashort Channel.
Science.gov (United States)
Xu, Wei; Hu, Zhanhao; Liu, Huimin; Lan, Linfeng; Peng, Junbiao; Wang, Jian; Cao, Yong
2016-01-01
Shrinking the device dimension has long been the pursuit of the semiconductor industry to increase the device density and operation speed. In the application of thin film transistors (TFTs), all-organic TFT arrays made by all-solution process are desired for low cost and flexible electronics. One of the greatest challenges is how to achieve ultrashort channel through a cost-effective method. In our study, ultrashort-channel devices are demonstrated by direct inkjet printing conducting polymer as source/drain and gate electrodes without any complicated substrate's pre-patterning process. By modifying the substrate's wettability, the conducting polymer's contact line is pinned during drying process which makes the channel length well-controlled. An organic TFT array of 200 devices with 2 μm channel length is fabricated on flexible substrate through all-solution process. The simple and scalable process to fabricate high resolution organic transistor array offers a low cost approach in the development of flexible and wearable electronics. PMID:27378163
3. Quasi-unipolar pentacene films embedded with fullerene for non-volatile organic transistor memories
International Nuclear Information System (INIS)
Quasi-unipolar non-volatile organic transistor memory (NOTM) can combine the best characteristics of conventional unipolar and ambipolar NOTMs and, as a result, exhibit improved device performance. Unipolar NOTMs typically exhibit a large signal ratio between the programmed and erased current signals but also require a large voltage to program and erase the memory cells. Meanwhile, an ambipolar NOTM can be programmed and erased at lower voltages, but the resulting signal ratio is small. By embedding a discontinuous n-type fullerene layer within a p-type pentacene film, quasi-unipolar NOTMs are fabricated, of which the signal storage utilizes both electrons and holes while the electrical signal relies on only hole conduction. These devices exhibit superior memory performance relative to both pristine unipolar pentacene devices and ambipolar fullerene/pentacene bilayer devices. The quasi-unipolar NOTM exhibited a larger signal ratio between the programmed and erased states while also reducing the voltage required to program and erase a memory cell. This simple approach should be readily applicable for various combinations of advanced organic semiconductors that have been recently developed and thereby should make a significant impact on organic memory research
4. New diarylmethanofullerene derivatives and their properties for organic thin-film solar cells
Directory of Open Access Journals (Sweden)
Daisuke Sukeguchi
2009-02-01
Full Text Available A number of diarylmethanofullerene derivatives were synthesized. The cyclopropane ring of the derivatives has two aryl groups substituted with electron-withdrawing and -donating groups, the latter with long alkyl chains to improve solubility in organic solvents, an important property in processing cells. First reduction potentials of most derivatives were less negative than that of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, which is possibly ascribed to their electron-withdrawing nature. Organic thin-film photovoltaic cells fabricated with poly(3-hexylthiophene (P3HT as the electron-donor and diarylmethanofullerene derivatives as the electron-acceptor material were examined. The {(methoxycarbonylphenyl[bis(octyloxyphenyl]methano}fullerene showed power conversion efficiency as high as PCBM, but had higher solubility in a variety of organic solvents than PCBM. The Voc value was higher than that of PCBM, which is derived from the electron-donating (octyloxyphenyl group, possibly raising the LUMO level. Photovoltaic effects of the devices fabricated with the derivatives having some electron-withdrawing groups were also examined.
5. The effect of pH and DNA concentration on organic thin-film transistor biosensors
KAUST Repository
2012-03-01
Organic electronics are beginning to attract more interest for biosensor technology as they provide an amenable interface between biology and electronics. Stable biosensor based on electronic detection platform would represent a significant advancement in technology as costs and analysis time would decrease immensely. Organic materials provide a route toward that goal due to their compatibility with electronic applications and biological molecules. In this report, we detail the effects of experimental parameters, such as pH and concentration, toward the selective detection of DNA via surface-bound peptide nucleic acid (PNA) sequences on organic transistor biosensors. The OTFT biosensors are fabricated with thin-films of the organic semiconductor, 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF), in which they exhibit a stable mobility of 0.2 cm 2 V -1 s -1 in buffer solutions (phosphate-buffer saline, pH 7.4 or sodium acetate, pH 7). Device performance were optimized to minimize the deleterious effects of pH on gate-bias stress such that the sensitivity toward DNA detection can be improved. In titration experiments, the surface-bound PNA probes were saturated with 50 nM of complementary target DNA, which required a 10-fold increase in concentration of single-base mismatched target DNA to achieve a similar surface saturation. The binding constant of DNA on the surface-bound PNA probes was determined from the concentration-dependent response (titration measurements) of our organic transistor biosensors. © 2011 Elsevier B.V. All rights reserved.
6. Organic molecular thin films as next-generation functional materials; Jisedai kinosei sozai to shite no yuki bunshi usumaku
Energy Technology Data Exchange (ETDEWEB)
Harima, H. [Hiroshima University, Hiroshima (Japan)
1998-08-25
Molecular materials as functional materials for the next generation are described. The thin film illuminates when a voltage is applied across two electrodes installed on both sides of a thin film fabricated of fluorescent dye. This phenomenon is called electroluminescence, and such a thin film is now being studied as a new display medium which may replace the CRT and liquid crystal. Molecular materials are under study as information recording materials. Photochromism is a process in which organic molecules reversibly change between two states different from each other in absorption spectrum under different irradiation, and the changes may be recorded as digital information. There is a super-high density recording system now drawing attention, which uses PHB (photochemical hole burning). In this system, laser beams different in wavelength are projected upon a spot in a thin film, which is a polymeric film with organic molecules dispersed therein, for the recording of more than several hundred pieces of information. It is expected that the new system will achieve a density 3 to 4 orders higher than that of the current optical recording system. The porphyrin thin film should also be named, which converts optical energy into electrical energy. 7 refs., 2 figs., 1 tab.
7. Effects of Plasma Polymer Films and Their Deposition Powers on the Barrier Characteristics of the Multilayer Encapsulation for Organic Devices.
Science.gov (United States)
Kim, Hoonbae; Ban, Wonjin; Kwon, Sungruel; Yong, Sanghyun; Chae, Heeyeop; Jung, Donggeun
2016-05-01
Organic electronic devices (OEDs) are quite suitable for use in flexible devices due to their ruggedness and flexibility. A number of researchers have studied the use of OEDs on flexible substrates in transparent, flexible devices in the near future. However, water and oxygen can permeate through the flexible substrates and can reduce the longevity of OEDs made from organic materials, which are weak to moisture and oxygen. In order to prevent the degradation of the OEDs, researchers have applied an encapsulation layer to the flexible substrates. In this study, Al2O3/plasma polymer film/Al2O3 multi-layers were deposited on polyethylene-naphthalate substrates through a combination of atomic layer deposition and plasma-enhanced chemical vapor deposition (PECVD). The plasma polymer film, which is located between the Al2O3 films, is deposited via PECVD with the use of a tetrakis(trimethylsilyloxy)silane precursor. The power of the plasma deposition varied from 10 to 50 W. The hydrophobicity of the plasma polymer film surfaces was investigated by measuring the water contact angle. The chemical structures of the plasma polymer films were measured via ex-situ Fourier transform infrared analysis. The permeation curves of the various films were analyzed by performing a calcium (Ca)-test. PMID:27483936
8. Metal-Organic Framework Thin Films as Stationary Phases in Microfabricated Gas-Chromatography Columns.
Energy Technology Data Exchange (ETDEWEB)
Read, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sillerud, Colin Halliday [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2016-01-01
The overarching goal of this project is to integrate Sandia's microfabricated gas-chromatography ( GC) columns with a stationary phase material that is capable of retaining high-volatility chemicals and permanent gases. The successful integration of such a material with GCs would dramatically expand the repertoire of detectable compounds for Sandia's various microanalysis systems. One such promising class of candidate materials is metal-organic frameworks (MOFs). In this report we detail our methods for controlled deposition of HKUST-1 MOF stationary phases within GC columns. We demonstrate: the chromatographic separation of natural gas; a method for determining MOF film thickness from chromatography alone; and the first-reported GC x GC separation of natural gas -- in general -- let alone for two disparate MOF stationary phases. In addition we determine the fundamental thermodynamic constant for mass sorption, the partition coefficient, for HKUST-1 and several light hydrocarbons and select toxic industrial chemicals.
9. Transient phases during fast crystallization of organic thin films from solution
Directory of Open Access Journals (Sweden)
Jing Wan
2016-01-01
Full Text Available We report an in situ microbeam grazing incidence X-ray scattering study of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT organic semiconductor thin film deposition by hollow pen writing. Multiple transient phases are observed during the crystallization for substrate temperatures up to ≈93 °C. The layered smectic liquid-crystalline phase of C8-BTBT initially forms and preceedes inter-layer ordering, followed by a transient crystalline phase for temperature >60 °C, and ultimately the stable phase. Based on these results, we demonstrate a method to produce extremely large grain size and high carrier mobility during high-speed processing. For high writing speed (25 mm/s, mobility up to 3.0 cm2/V-s has been observed.
10. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks
Directory of Open Access Journals (Sweden)
Wencai Zhou
2015-06-01
Full Text Available The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs, is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM, the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1, whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.
11. Preparation and characteristics of flexible all-organic thin-film field-effect transistor
Institute of Scientific and Technical Information of China (English)
QIU Yong; HU Yuanchuan; Dong Guifang; WANG Liduo; Xie Junfeng; MA Yaning
2003-01-01
All-organic thin-film field-effect transistor was prepared on flexible poly(ethylene-terephthalate) (PET) substrate. Poly(methyl-methacrylate) (PMMA) and pentacene are used as a dielectric layer and a semiconductor layer, respectively. The hole mobility of the transistor can reach 2.10×10-2 cm2/Vs, and the on/off current ratio was larger than 105. The performances of the transistor, when the substrate is cured under different radius, were also measured. It was found that the device performance did not change when the curly direction was vertical to the channel length direction and when the curly direction was parallel to the channel length direction with 3.67 cm curvature radius, the mobility of the device increased by more than 20% and the on/off ratio decreased more than one order.
12. Transient phases during fast crystallization of organic thin films from solution
Science.gov (United States)
Wan, Jing; Li, Yang; Ulbrandt, Jeffrey G.; Smilgies, Detlef-M.; Hollin, Jonathan; Whalley, Adam C.; Headrick, Randall L.
2016-01-01
We report an in situ microbeam grazing incidence X-ray scattering study of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) organic semiconductor thin film deposition by hollow pen writing. Multiple transient phases are observed during the crystallization for substrate temperatures up to ≈93 °C. The layered smectic liquid-crystalline phase of C8-BTBT initially forms and preceedes inter-layer ordering, followed by a transient crystalline phase for temperature >60 °C, and ultimately the stable phase. Based on these results, we demonstrate a method to produce extremely large grain size and high carrier mobility during high-speed processing. For high writing speed (25 mm/s), mobility up to 3.0 cm2/V-s has been observed.
13. Flexible, all-organic ammonia sensor based on dodecylbenzene sulfonic acid-doped polyaniline films
International Nuclear Information System (INIS)
A stable chlorobenzene dispersion of conducting polyaniline (PANI) has been obtained by doping emeraldine base with dodecylbenzene sulfonic acid (DBSA) and studied by spectrophotometric measurements in the UV-vis-IR range. The electrical properties of PANI: DBSA films obtained from the above dispersion have been investigated under different temperature and relative humidity conditions. All-organic chemoresistive devices have been developed by spin-coating the PANI: DBSA dispersion on flexible substrates, and then by depositing electrodes on the top, from a carbon nanotube conducting ink. Sensing tests performed under exposition to calibrated amounts of ammonia reveal that these simple and inexpensive sensors are able to detect ammonia at room temperature in a reliable way, with a sensitivity linearly related to concentration in the range between 5 ppm and 70 ppm.
14. A water-gated organic thin film transistor as a sensor for water-borne amines.
Science.gov (United States)
Algarni, Saud A; Althagafi, Talal M; Naim, Abdullah Al; Grell, Martin
2016-06-01
The p-type semiconducting polymer Poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) displays innate sensitivity to water-borne amines. We demonstrate this with the help of water-gated PBTTT thin film transistors (TFTs). When octylamine is added to the gating water, TFTs respond with a significantly reduced saturated drain current. Underlying TFT drift is minimised by initial conditioning, and remaining drift can be accounted for by normalising current response to the current level under purge immediately before exposure. Normalised current response vs. amine concentration is reproducible between different transistors, and can be modelled by a Langmuir surface adsorption isotherm, which suggests physisorption of analyte at the PBTTT surface, rather than bulk penetration. Same PBTTT transistors do not respond to 1- octanol, confirming the specific affinity between amines and thiophene- based organic semiconductors. PMID:27130096
15. Pentacene organic thin-film transistors on flexible paper and glass substrates
International Nuclear Information System (INIS)
Pentacene-based organic thin-film transistors (OTFTs) were fabricated on several types of flexible substrate: commercial photo paper, ultra-smooth specialty paper and ultra-thin (100 μM) flexible glass. The transistors were fabricated entirely through dry-step processing. The transconductance and field-effect mobility of OTFTs on photo paper reached values of ∼0.52 mS m−1 and ∼0.1 cm2 V −1 s−1, respectively. Preliminary results on the lifetime of OTFTs on photo paper yielded stable transconductance and mobility values over a period of more than 250 h. The comparable characteristics of OTFTs fabricated on widely available, low cost paper and high quality expensive liquid crystal display glass indicate the potential importance of cellulose-based electronic devices. (paper)
16. Laboratory Studies of Hydrocarbon Nucleation on Tholin Particles and Thin Organic Films: Application to Titan's Atmosphere
Science.gov (United States)
Curtis, Daniel B.; Glandorf, David L.; Toon, Owen B.; Tolbert, Margaret A.; McKay, Christopher P.; Khare, Bishun N.
2001-01-01
Titan, Saturn's largest satellite, has a thick nitrogen/methane atmosphere. In Titan's lower atmosphere, methane is saturated or supersaturated with respect to nucleation and may form clouds. To better characterize the properties of Titan's methane clouds we have measured the saturation ratio required to obtain butane nucleation, S (sub crit), on Titan tholin material and organic films. We find a critical saturation ratio for butane on tholin particles of S (sub crit) = 1.40, suggesting high supersaturations are required for nucleation. If methane is similar to butane, we expect high supersaturations of methane as well. This could favor the formation of a small number of large particles, consistent with recent measurements of methane rain on Titan.
17. Effect of curing temperature on nano-silver paste ink for organic thin-film transistors.
Science.gov (United States)
Kim, Minseok; Koo, Jae Bon; Baeg, Kang-Jun; Noh, Yong-Young; Yang, Yong Suk; Jung, Soon-Won; Ju, Byeong-Kwon; You, In-Kyu
2012-04-01
Silver (Ag) metal electrode having 20 microm channel length was printed by reverse offset printing (ROP) using nano-silver paste ink for the source/drain of organic thin-film transistors (OTFT). Specific resistance and surface roughness of printed Ag electrodes with increasing curing temperature were investigated, and surface morphology and grain growth mechanism were systematically verified using a scanning electron microscope (SEM) and atomic force microscope (AFM) in order to obtain an optimized ROP Ag electrode. The Ag electrode was applied to fabricate top-gate/bottom-contact poly(3-hexylthiophene) OTFT devices, which showed reproducible OTFT characteristics such as the field-effect mobility, threshold voltage, and an on/off-current ratio of -10(-3) cm2/Vs, 0.36 V, and -10(2), respectively. PMID:22849104
18. Effects of neutral particle beam on nano-crystalline silicon thin films, with application to thin film transistor backplane for flexible active matrix organic light emitting diodes
Energy Technology Data Exchange (ETDEWEB)
Jang, Jin Nyoung; Song, Byoung Chul; Lee, Dong Hyeok [Dept. of Display and Semiconductor Physics, Korea University, Chungnam (Korea, Republic of); Yoo, Suk Jae; Lee, Bonju [National Fusion Research Institute, 52, Yuseong-Gu, Deajeon, 305-333 (Korea, Republic of); Hong, MunPyo, E-mail: [email protected] [Dept. of Display and Semiconductor Physics, Korea University, Chungnam (Korea, Republic of)
2011-08-01
A novel deposition process for nano-crystalline silicon (nc-Si) thin films was developed using neutral beam assisted chemical vapor deposition (NBaCVD) technology for the application of the thin film transistor (TFT) backplane of flexible active matrix organic light emitting diode (AMOLED). During the formation of a nc-Si thin film, the energetic particles enhance nano-sized crystalline rather microcrystalline Si in thin films. Neutral Particle Beam (NPB) affects the crystallinity in two ways: (1) NPB energy enhances nano-crystallinity through kinetic energy transfer and chemical annealing, and (2) heavier NPB (such as Ar) induces damage and amorphization through energetic particle impinging. Nc-Si thin film properties effectively can be changed by the reflector bias. As increase of NPB energy limits growing the crystalline, the performance of TFT supports this NPB behavior. The results of nc-Si TFT by NBaCVD demonstrate the technical potentials of neutral beam based processes for achieving high stability and reduced leakage in TFT backplanes for AMOLEDs.
19. Impact of universal mobility law on polycrystalline organic thin-film transistors
Science.gov (United States)
Raja, Munira; Donaghy, David; Myers, Robert; Eccleston, Bill
2012-10-01
We have developed novel analytical models for polycrystalline organic thin-film transistor (OTFT) by employing new concepts on the charge carrier injection to polysilicon thin-films. The models, also incorporate the effect of contact resistance associated with the poor ohmic nature of the contacts. The drain current equations of the OTFT, both in the quasi-diffusion and quasi-drift regimes, predict temperature dependencies on essential material and device parameters. Interestingly, under the drift regime, the polycrystalline OTFT model reveals similar power dependencies on the applied voltages, to those of purely disordered model developed by utilizing the universal mobility law (UML). Such similarities are not thought to be coincidental since the effect of gate voltage on surface potential is influenced by the Fermi level pinning in the grain boundary. Nonetheless, the best fits on the data of 6,13-bis(tri-isopropylsilylethynyl) OTFTs are attained with the proposed polycrystalline rather than the disordered model, particularly at low gate voltages where the diffusive component is dominant. Moreover, in order to understand the effect of grain boundaries, we devise a relationship for the dependency of the effective mobility on carrier concentration, assuming a crystalline region to be in direct contact with a disordered region. Interestingly, we find a similar dependency as the UML in purely disordered materials, which further signifies the conduction to be limited by the grain boundaries. Subsequently, an analytical model for the variation of the effective mobility with gate voltage is established. Such models are vital in assisting the development of more accurate designs of the novel organic circuits.
20. Ordered conducting polymer multilayer films and its application for hole injection layers in organic light-emitting devices
International Nuclear Information System (INIS)
We reported a controlled architecture growth of layer-ordered multilayer film of poly(3,4-ethylene dioxythiophene) (PEDOT) via a modified Langmuir-Blodgett (LB) method. An in situ polymerization of 3,4-ethylene dioxythiophene (EDOT) monomer in multilayer LB film occurred for the formation of ordered conducting polymer embedded multilayer film. The well-distribution of conducting polymer particles was characterized by secondary-ion mass spectrometry (SIMS). The conducting film consisting of ordered PEDOT ultrathin layers was investigated as a hole injection layer for organic light-emitting diodes (OLEDs). The results showed that, compared to conventional spin-coating PEDOT film and electrostatic self-assembly (ESA) film, the improved performance of OLEDs was obtained after using ordered PEDOT LB film as hole injection layer. It also indicated that well-ordered structure of hole injection layer was attributed to the improvement of OLED performance, leading to the increase of charged carrier mobility in hole injection layer and the recombination rate of electrons and holes in the electroluminescent layer.
1. Ordered conducting polymer multilayer films and its application for hole injection layers in organic light-emitting devices
Science.gov (United States)
Xu, Jianhua; Yang, Yajie; Yu, Junsheng; Jiang, Yadong
2009-01-01
We reported a controlled architecture growth of layer-ordered multilayer film of poly(3,4-ethylene dioxythiophene) (PEDOT) via a modified Langmuir-Blodgett (LB) method. An in situ polymerization of 3,4-ethylene dioxythiophene (EDOT) monomer in multilayer LB film occurred for the formation of ordered conducting polymer embedded multilayer film. The well-distribution of conducting polymer particles was characterized by secondary-ion mass spectrometry (SIMS). The conducting film consisting of ordered PEDOT ultrathin layers was investigated as a hole injection layer for organic light-emitting diodes (OLEDs). The results showed that, compared to conventional spin-coating PEDOT film and electrostatic self-assembly (ESA) film, the improved performance of OLEDs was obtained after using ordered PEDOT LB film as hole injection layer. It also indicated that well-ordered structure of hole injection layer was attributed to the improvement of OLED performance, leading to the increase of charged carrier mobility in hole injection layer and the recombination rate of electrons and holes in the electroluminescent layer.
2. Electric and ferroelectric properties of PZT/BLT multilayer films prepared by photochemical metal-organic deposition
Energy Technology Data Exchange (ETDEWEB)
Park, Hyeong-Ho; Lee, Hong-Sub [Department of Ceramic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Ku, Seoul 120-749 (Korea, Republic of); Park, Hyung-Ho [Department of Ceramic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Ku, Seoul 120-749 (Korea, Republic of)], E-mail: [email protected]; Hill, Ross H. [4D Labs and Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Hwang, Yun Taek [Research and semiconductor Division, Hynix semiconductor Inc., Icheon-si, Kyoungki-do 467-701 (Korea, Republic of)
2009-01-15
The electric and ferroelectric properties of lead zirconate titanate (PZT) and lanthanum-substituted bismuth titanate (BLT) multilayer films prepared using photosensitive precursors were characterized. The electric and ferroelectric properties were investigated by studying the effect of the stacking order of four ferroelectric layers of PZT or BLT in 4-PZT, PZT/2-BLT/PZT, BLT/2-PZT/BLT, and 4-BLT multilayer films. The remnant polarization values of the 4-BLT and BLT/2-PZT/BLT multilayer films were 12 and 17 {mu}C/cm{sup 2}, respectively. Improved ferroelectric properties of the PZT/BLT multilayer films were obtained by using a PZT intermediate layer. The films which contained a BLT layer on the Pt substrate had improved leakage currents of approximately two orders of magnitude and enhanced fatigue resistances compared to the films with a PZT layer on the Pt substrate. These improvements are due to the reduced number of defects and space charges near the Pt electrodes. The PZT/BLT multilayer films prepared by photochemical metal-organic deposition (PMOD) possessed enhanced electric and ferroelectric properties, and allow direct patterning to fabricate micro-patterned systems without dry etching.
3. Ultrathin and ultrasmooth Au films as transparent electrodes in ITO-free organic light-emitting devices.
Science.gov (United States)
Bi, Yan-Gang; Feng, Jing; Ji, Jin-Hai; Chen, Yang; Liu, Yu-Shan; Li, Yun-Fei; Liu, Yue-Feng; Zhang, Xu-Lin; Sun, Hong-Bo
2016-05-21
An ultrathin, ultrasmooth and flexible Au film as an alternative of the indium-tin oxide (ITO) electrode in organic light-emitting devices (OLEDs) has been reported. The 7 nm Au film shows excellent surface morphology, optical and electronic characteristics including a root-mean-square roughness of 0.35 nm, a high transparency of 72% at 550 nm, and a sheet resistance of 23.75 Ω sq(-1). These features arise from the surface modification of the glass substrate by using a SU-8 film, which fixes metal atoms via chemical bond interactions between Au and SU-8 film to suppress the island growth mode. A 17% enhancement in current efficiency has been obtained from the OLEDs based on the ultrathin Au electrodes compared to that of the devices with the ITO electrodes. The OLEDs with the ultrathin Au/SU-8 anodes exhibit high flexibility and mechanical robustness. PMID:27128168
4. MODIFICATION OF CARBONACEOUS ADSORBENTS WITH MANGANESE COMPOUNDS
OpenAIRE
Irina Ginsari; Larisa Postolachi; Vasile Rusu; Oleg Petuhov; Tatiana Goreacioc; Tudor Lupascu; Raisa Nastas
2015-01-01
Four series of samples containing manganese supported carbonaceous adsorbents were prepared. Obtained results reveal the importance of surface chemistry of carbonaceous adsorbents on the manganese loading.
5. A computational chemical study of penetration and displacement of water films near mineral surfaces
Directory of Open Access Journals (Sweden)
Larter Steve R
2001-08-01
Full Text Available A series of molecular dynamics simulations have been performed on organic–water mixtures near mineral surfaces. These simulations show that, in contrast to apolar compounds, small polar organic compounds such as phenols can penetrate through thin water films to adsorb on these mineral surfaces. Furthermore, additional simulations involving demixing of an organic–water mixture near a surfactant-covered mineral surface demonstrate that even low concentrations of adsorbed polar compounds can induce major changes in mineral surface wettability, allowing sorption of apolar molecules. This strongly supports a two-stage adsorption mechanism for organic solutes, involving initial migration of small polar organic molecules to the mineral surface followed by water film displacement due to co-adsorption of the more apolar organic compounds, thus converting an initial water-wet mineral system to an organic-covered surface. This has profound implications for studies of petroleum reservoir diagenesis and wettability changes.
6. Hydrophobic plasma polymerized hexamethyldisilazane thin films: characterization and uses
Directory of Open Access Journals (Sweden)
Alexsander Tressino de Carvalho
2006-03-01
Full Text Available Hexametildisilazane (HMDS plasma polymerized thin films obtained using low frequency power supplies can be used to make adsorbent films and turn surfaces hydrophobic. The aim of this work was to verify the hydrophobicity and adsorption properties of HMDS thin films (with and without the addition of oxygen, resulting in double or single layer films obtained using an inductive reactor powered with a 13.56 MHz power supply. Single and double layer thin films were deposited on silicon for film characterization, polypropylene (PP for ultraviolet (UVA/UVC resistance tests, piezoelectric quartz crystal for adsorption tests. The double layer (intermixing of HMDS plasma polymerized films and HMDS plasma oxidized surfaces showed a non-continuous layer. The films showed good adhesion to all substrates. Infrared analysis showed the presence of CHn, SiCH3, SiNSi and SiCH2Si within the films. Contact angle measurements with water showed hydrophobic surfaces. UVA/UVC exposure of the films resulted in the presence of cross-linking on carbonic radicals and SiCH2Si formation, which resulted in a possible protection of PP against UVA/UVC for a duration of up to two weeks. Adsorption tests showed that all organic reactants were adsorbed but not water. Plasma etching (PE using O2 showed that even after 15 minutes of exposure the films do not change their hydrophobic characteristic but were oxidized. The results point out that HMDS films can be used: for ultraviolet protection of flexible organic substrates, such as PP, for sensor and/or preconcentrator development, due to their adsorption properties, and in spatial applications due to resistance for O2 attack in hostile conditions, such as plasma etching.
7. Low-voltage polymer/small-molecule blend organic thin-film transistors and circuits fabricated via spray deposition
Energy Technology Data Exchange (ETDEWEB)
Hunter, By Simon; Anthopoulos, Thomas D., E-mail: [email protected] [Department of Physics and Centre for Plastic Electronics, Imperial College London, South Kensington SW7 2AZ (United Kingdom); Ward, Jeremy W.; Jurchescu, Oana D. [Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109 (United States); Payne, Marcia M.; Anthony, John E. [Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506 (United States)
2015-06-01
Organic thin-film electronics have long been considered an enticing candidate in achieving high-throughput manufacturing of low-power ubiquitous electronics. However, to achieve this goal, more work is required to reduce operating voltages and develop suitable mass-manufacture techniques. Here, we demonstrate low-voltage spray-cast organic thin-film transistors based on a semiconductor blend of 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene and poly(triarylamine). Both semiconductor and dielectric films are deposited via successive spray deposition in ambient conditions (air with 40%–60% relative humidity) without any special precautions. Despite the simplicity of the deposition method, p-channel transistors with hole mobilities of >1 cm{sup 2}/Vs are realized at −4 V operation, and unipolar inverters operating at −6 V are demonstrated.
8. Evaluating phosphorus availability in soils receiving organic amendment application using the Diffusive Gradients in Thin-films (DGT) technique
OpenAIRE
Kane, David
2013-01-01
Phosphorus is a resource in finite supply. Use of organic amendments in agriculture can be a sustainable alternative to inorganic P, provided it can meet crop requirements. However a lack of consistent knowledge of plant P availability following application of organic amendments, limits its potential. Studies suggest chemical extraction procedures, may not reflect plant available P. The Diffusive Gradients in Thin-films (DGT) technique is based on natural diffusion of P via a hydrogel and sor...
9. Monolithically integrated, flexible display of polymer-dispersed liquid crystal driven by rubber-stamped organic thin-film transistors
International Nuclear Information System (INIS)
This letter describes the monolithic integration of rubber-stamped thin-film organic transistors with polymer-dispersed liquid crystals (PDLCs) to create a multipixel, flexible display with plastic substrates. We report the electro-optic switching behavior of the PDLCs as driven by the organic transistors, and we show that our displays operate robustly under flexing and have a contrast comparable to that of newsprint. [copyright] 2001 American Institute of Physics
10. Thiol anchoring and catalysis of gold nanoparticles at the liquid interface of thin-organic film-modified electrodes
OpenAIRE
Mirceski, Valentin; Aleksovska, Angela; Pejova, Biljana; Ivanovski, Vladimir; Mitrova, Biljana; Mitreska, Nikolina; Gulaboski, Rubin
2014-01-01
The deposition of in-situ formed gold nanoparticles at the liquid/liquid (L/L) interface is studied by means of thin-organic-film-modified electrodes (TFE). The degree of ordering and aggregation of gold nanoparticles can be tuned by adding a lipophilic and hydrophilic thiol in the organic and aqueous phase, respectively. The ordered thiol-anchored gold nanoparticles exhibit pronounced catalytic effect toward electron-transfer reactions across the L/L interface.
11. Studying the ion transfer across liquid interface of thin organic-film-modified electrodes in the presence of glucose oxidase
OpenAIRE
Mirceski, Valentin; Mitrova, Biljana; Ivanovski, Vladimir; Mitreska, Nikolina; Aleksovska, Angela; Gulaboski, Rubin
2015-01-01
A coupled electron-ion transfer reaction at thin organic-film-modified electrodes (TFE) is studied in the presence of glucose oxidase (GOx) under voltammetric conditions. TFE consists of a graphite electrode modified with a nitrobenzene solution of decamethylferrocene (DMFC) as a redox mediator and tetrabuthylammonium perchlorate as an organic-supporting electrolyte, in contact with aqueous buffer solutions containing percholarte ions and GOx. The redox turnover of DMFC coupled with perchl...
12. Characterizations of arsenic-doped zinc oxide films produced by atmospheric metal-organic chemical vapor deposition
International Nuclear Information System (INIS)
p-type ZnO films were prepared by atmospheric metal-organic chemical vapor deposition technique using arsine (AsH3) as the doping source. The electrical and optical properties of arsenic-doped ZnO (ZnO:As) films fabricated at 450–600 °C with various AsH3 flow rates ranging from 8 to 21.34 μmol/min were analyzed and compared. Hall measurements indicate that stable p-type ZnO films with hole concentrations varying from 7.2 × 1015 to 5.8 × 1018 cm−3 could be obtained. Besides, low temperature (17 K) photoluminescence spectra of all ZnO:As films also demonstrate the dominance of the line related to the neutral acceptor-bound exciton. Moreover, the elemental identity and chemical bonding information for ZnO:As films were examined by X-ray photoelectron spectroscopy. Based on the results obtained, the effects of doping conditions on the mechanism responsible for the p-type conduction were studied. Conclusively, a simple technique to fabricate good-quality p-type ZnO films has been recognized in this work. Depositing the film at 550 °C with an AsH3 flow rate of 13.72 μmol/min is appropriate for producing hole concentrations on the order of 1017 cm−3 for it. Ultimately, by increasing the AsH3 flow rate to 21.34 μmol/min for doping and depositing the film at 600 °C, ZnO:As films with a hole concentration over 5 × 1018 cm−3 together with a mobility of 1.93 cm2V−1 s−1 and a resistivity of 0.494 ohm-cm can be achieved.
13. Effect of fluorine plasma treatment with chemically reduced graphene oxide thin films as hole transport layer in organic solar cells
Energy Technology Data Exchange (ETDEWEB)
Yu, Youn-Yeol; Kang, Byung Hyun; Lee, Yang Doo; Lee, Sang Bin; Ju, Byeong-Kwon, E-mail: [email protected]
2013-12-15
The inorganic materials such as V{sub 2}O{sub 5}, MoO{sub 3} and WO{sub 3} were investigated to replace PEDOT:PSS as hole transport layer (HTL) in organic electronic devices such as organic solar cells (OSCs) and organic lighting emission diodes. However, these methods require vacuum techniques that are long time process and complex. Here, we report about plasma treatment with SF{sub 6} and CF{sub 4} using reactive ion etching on reduced graphene oxide (rGO) thin films that are obtained using an eco-friendly method with vitamin C. The plasma treated rGO thin films have dipoles since they consist of covalent bonds with fluorine on the surface of rGO. This means it is possible to increase the electrostatic potential energy than bare rGO. Increased potential energy on the surface of rGO films is worth applying organic electronic devices as HTL such as OSCs. Consequently, the power conversion efficiency of OSCs increased more than the rGO films without plasma treatment.
14. Plasma-polymerized films providing selective affinity to the polarity of vaporized organic solvents
International Nuclear Information System (INIS)
Plasma-polymerized films (PPFs) were fabricated as recognition membranes for a vapor-sensing device, and their affinity to vaporized organic solvents was evaluated with surface plasmon resonance. The affinity we intended to create is the selective sorption of the vaporized organic solvents depending on their polarity. For this purpose, acetonitrile, ethylenediamine (EDA), styrene, hexamethyldisiloxane (HMDSO), and hexamethyldisilazane were used to fabricate PPFs. Vaporized methanol, ethanol, and 1-propanol were used as high-polar solvents to be analyzed. Hexane, toluene, and p-xylene were used as low-polar solvents. As a result, the HMDSO-PPF with 97.3o of contact angle was found to provide affinity to the low-polar solvents. In contrast, the EDA-PPF with 7.1o of contact angle provided affinity to the high-polar solvents. Observations of the surface morphology of the HMDSO- and EDA-PPFs with a scanning electron microscope revealed that they are composed of nano-scale islands.
15. Roll-printed organic thin-film transistor using patterned poly(dimethylsiloxane) (PDMS) stamp.
Science.gov (United States)
Jo, Jeongdai; Yu, Jong-Su; Lee, Taik-Min; Kim, Dong-Soo; Kim, Kwang-Young
2010-05-01
The roll-printed gate, source, and drain electrodes of organic thin-film transistors (OTFTs) were fabricated by gravure printing or gravure-offset printing using patterned poly(dimethylsiloxane) (PDMS) stamp with various channel lengths and low-resistance silver (Ag) pastes on flexible 150 x 150 mm2 plastic substrates. Bottom-contact roll-printed OTFTs used polyvinylphenol (PVP) as polymeric dielectric and bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) as organic semiconductor; they were formed by spin coating or ink-jetting. Depending on the choice of roll-printing method, the printed OTFTs obtained had a field-effect mobility of between 0.08 and 0.1 cm2/Vs, an on/off current ratio of between 10(4) and 10(5), and a subthreshold slope of between 1.96 and 2.32 V/decade. The roll-printing using patterned PDMS stamp and soluble processes made it possible to fabricate a printed OTFT with a channel length of between 12 to 74 microm on a plastic substrate; this was not previously possible using traditional printing techniques. The proposed fabrication process was 20 steps shorted than conventional fabrication techniques. PMID:20359007
16. Overview of recent developments in organic thin-film transistor sensor technology
International Nuclear Information System (INIS)
Bio and chemical sensing represents one of the most attractive applications of organic electronics and of Organic Thin Film Transistors(OTFTs) in particular. The implementation of miniaturized portable systems for the detection of chemical analytes as well as of biological species, is still a challenge for the sensor' community. In this respect OTFTs appear as a new class of sensors able, in principle, to overcome some of the commercial sensors drawbacks. As far as volatile analytes are concerned, commercially available sensing systems, such as metal oxide based chemi-resistors, offer great stability but rather poor selectivity. In spite of the improved selectivity offered by organic chemi-resistors the reliability of such devices is not yet satisfactory proven. On the other hand, complex odors recognition, but also explosives or pathogen bacteria detection are currently being addressed by sensor array systems, called e-noses, that try to mimic the mammalian olfactory system. Even though potentially very effective, this technology has not yet reached the performance level required by the market mostly because miniaturization and cost effective production issues. OTFT sensors can offer the advantage of room temperature operation and deliver high repeatable responses. Beside, they show very good selectivity properties. In fact, they implement organic active layers, which behave as sensing layers as well. This improves OTFTs sensitivity towards different chemical and biological analytes as organic materials can be properly chemically tailored to achieve differential detection and potentially even discrimination of biological species. In addiction to this, OTFTs are also able to offer the unique advantages of multi-parametric response and a gate bias enhanced sensitivity. Recently thin dielectric low-voltage OTFTs have also been demonstrated. Their implementation in low power consumption devices has attracted the attention of the organic electronic community. But such
17. The Production of Organic-Inorganic Compound Film-Coated Urea and the Characteristics of Its Nutrient Release
Institute of Scientific and Technical Information of China (English)
ZOU Hong-tao; WANG Yao-sheng; SONG Hao-wen; HAN Yan-yu; YU Na; ZHANG Yu-ling; DANG Xiu-li; HUANG Yi; ZHANG Yu-long
2009-01-01
The effect of different concentrations of natural macromolecular compound on the characteristics of nutrient release in the membrane materials of organic-inorganic compound film-coated urea was discussed,and the optimal concentrations for better nutrient release was proposed.The characteristics of nutrient release of film-coated urea were evaluated by soil column leaching experiment.Organic-inorganic compound film-coated urea showed good characteristics of nutrient release,which could be well simulated by Logistic curve.The two parameters in this curve,a and r,can be used to present nutrient release of film-coated urea,and followed the order of B ＞ C ＞ A and C ＜ B ＜ A,respectively,indicating that the release was stronger with the increasing concentration of natural maeromolecular compound in the membrane,which implied better controllability of nutrient release.The concentration of 5% of natural macromolecular compound showed better characteristic of nutrient release and can be utilized as a membrane material combined with inorganic mineral powders to develop film-coated slow-release fertilizer.
18. P-type indium oxide thin film for the hole-transporting layer of organic solar cells
International Nuclear Information System (INIS)
Efficient organic solar cells (OSCs) based on regioregular of poly (3-hexylthiophene): fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester composites have been fabricated on fluorine-doped tin oxide coated glass substrates by using a sputtered indium oxide film as a hole-transporting layer (HTL). Optimized parameters for p-type In2O3 layer fabrication have been obtained through In2O3 layer sputtering temperature modulation. Based on this HTL, photovoltaic devices have been fabricated, and a power conversion efficiency up to 1.32% has been achieved. With the help of X-ray photoelectron spectroscopy and Hall-effect measurements, we conclude that the formation of In(OH)3/InOOH on the surface of In2O3 film could increase the electrical resistivity of films and affect the performance of OSC further. - Highlights: ► The p-type In2O3 films were fabricated using the magnetron sputtering method. ► The p-type In2O3 films have been applied to the hole-transporting layer. ► The formation of In(OH)3/InOOH affects the performance of organic solar cells.
19. In situ vibrational spectroscopy of thin organic films confined at the solid-solid interface
International Nuclear Information System (INIS)
Raman scattering was used to study thin films, of hexadecane, octamethyltetrasiloxane (OMCTS), 1-undecanol and Langmuir-Blodgett (LB) monolayers consisting of zinc stearate, zinc arachidate and zinc behenate, all at the solid-solid interface. This thesis contains the first unenhanced Raman spectrum of an organic monolayer confined in the contact between two solid surfaces. The LB monolayers were also investigated with sum-frequency spectroscopy in order that comparisons could be made between results from the two techniques. Thin films were confined between an optical prism and an optical lens at pressures ranging from 30 MPa to 200 MPa. I have shown that the deposited LB monolayers were conformationally ordered and that this high degree of order was retained at applied pressures of up to 200 MPa. However, the application of pressure caused the hydrocarbon chains to tilt from the surface normal. The changes observed in the overall intensity of the Raman spectra on formation of the solid-solid contact can be explained by changes in electric field strengths, but this interpretation cannot be made in the case of the SF spectra. The SF signal arising from the monolayer confined between the two solid surfaces was often much lower than predicted, and this is discussed in terms of structural changes and transfer of monolayer material from one surface to the other. Liquid lubricants were squeezed almost completely out of the solid-solid contact at pressures of 40 MPa. However, the use of a total internal reflection (TIR) excitation geometry in the Raman experiments increased the sensitivity of this technique sufficiently for spectra to be obtained from sub-monolayer amounts of material that had collected in small surface defects, with acquisition times of minutes. (author)
20. Hydrophilic property of SiO2/TiO2 double layer films
International Nuclear Information System (INIS)
The hydrophilicity of the SiO2(top)/TiO2(under) double layer films prepared by vacuum evaporation was investigated. The as-deposited SiO2/TiO2 double layer films showed very good hydrophilicity (water contact angle: ∼0o). Their hydrophilicity, however, is deteriorated by the organic contamination adsorbed on the film but the hydrophilicity can be recovered by UV light irradiation. TOF-SIMS (time-of-flight secondary-ion-mass-spectrometry) measurements revealed that the amount of organic compounds adsorbed on the films decreased with the UV light irradiation. Secondarily, the amount of both Si-OH and Ti-OH groups changed little by the UV light irradiation. Thus, it can be concluded that the hydrophilicity of the SiO2/TiO2 double layer films is due to the stable Si-OH groups and the photo-catalytic TiO2 underlayer maintains the hydrophilicity of the double layer films by decomposing organic contaminants on the film surface. This SiO2/TiO2 double layer film has been in practical use for the automobiles' exterior rear view mirrors
1. Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films
KAUST Repository
Ren, Yi
2011-07-01
Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities to selectively anneal certain components of the device, while leaving others intact. On the downside, these interactions are complex and rather unpredictable, requiring further investigation. We propose a novel methodology to investigate solvent-film interactions, based on use of an in situ quartz crystal microbalance with dissipation (QCM-D) capability and in situ grazing incidence wide angle X-ray scattering (GIWAXS). These methods make it possible to investigate both qualitatively and quantitatively the solvent vapor uptake, the resulting softening and changes (reversible and/or irreversible) in crystallinity. Using this strategy, we have investigated the solvent vapor annealing of traditional donor and acceptor materials, namely poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM). We find these materials retain their rigid structure during toluene vapor annealing and do not dewet. We also investigated the toluene vapor annealing of several newly proposed acceptor molecules (pentacene-based) modified with various silyl groups and electron withdrawing groups to tune the packing structure of the acceptor domains and energy levels at the donor-acceptor interface. We found a dramatic effect of the electron-withdrawing group on vapor uptake and whether the film remains rigid, softens, or dissolves completely. In the case of trifluoromethyl electron-withdrawing group, we found the film dissolves, resulting in complete and irreversible loss of long range order. By contrast, the cyano group prevented loss of long range order, instead promoting crystallization in some cases. The silyl groups had a secondary effect in comparison to these. In the last part of the thesis, we investigated the
2. Effect of Polymer Binders on UV-Responsive Organic Thin-Film Phototransistors with Benzothienobenzothiophene Semiconductor.
Science.gov (United States)
Ljubic, Darko; Smithson, Chad S; Wu, Yiliang; Zhu, Shiping
2016-02-17
The influence of polymer binders on the UV response of organic thin-film phototransistors (OTF-PTs) is reported. The active channel of the OTF-PTs was fabricated by blending a UV responsive 2,7-dipenty-[1]benzothieno[2,3-b][1]benzothiophene (C5-BTBT) as small molecule semiconductor and a branched unsaturated polyester (B-upe) as dielectric binder (ratio 1:1). To understand the influence of the polymer composition on the photoelectrical properties and UV response of C5-BTBT, control blends were prepared using common dielectric polymers, namely, poly(vinyl acetate) (PVAc), polycarbonate (PC), and polystyrene (PS), for comparison. Thin-film morphology and nanostructure of the C5-BTBT/polymer blends were investigated by means of optical and atomic force microscopy, and powder X-ray diffraction, respectively. Electrical and photoelectrical characteristics of the studied OTF-PTs were evaluated in the dark and under UV illumination with a constant light intensity (P = 3 mW cm(-2), λ = 365 nm), respectively, using two- and three-terminal I-V measurements. Results revealed that the purposely chosen B-upe polymer binder strongly affected the UV response of OTF-PTs. A photocurrent increase of more than 5 orders of magnitude in the subthreshold region was observed with a responsivity as high as 9.7 AW(-1), at VG = 0 V. The photocurrent increase and dramatic shift of VTh,average (∼86 V) were justified by the high number of photogenerated charge carriers upon the high trap density in bulk 8.0 × 10(12) cm(-2) eV(-1) generated by highly dispersed C5-BTBT in B-upe binder. Compared with other devices, the B-upe OTF-PTs had the fastest UV response times (τr1/τr2 = 0.5/6.0) reaching the highest saturated photocurrent (>10(6)), at VG = -5 V and VSD = -60 V. The enhanced UV sensing properties of B-upe based OTF-PTs were attributed to a self-induced thin-film morphology. The enlarged interface facilitated the electron withdrawing/donating functional groups in the polymer chains in
3. Preparation of TiO2 thin film by the LPD method on functionalized organic self-assembled monolayers
Institute of Scientific and Technical Information of China (English)
2009-01-01
In this paper, uniform titania (TiO2) films have been formed at 50℃ on silanol SAMs by the liquid-phase deposition (LPD) method at a temperature below 100℃. OTS (Octadecyltrichloro-Silane) selfassembled monolayers (SAMs) on glass wafers were used as substrates for the deposition of titanium dioxide thin films. This functionalized organic surface has shown to be effective for promoting the growth of films from titanic aqueous solutions by the LPD method at a low temperature below 100℃. The crystal phase composition, microstructure and topography of the as-prepared films were characterized by various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicate that the as-prepared thin films are purely crystallized anatase TiO2 constituted by nanorods after being annealed at 500℃. The pH values, concentration of reactants, and deposition temperatures play important roles in the growth of TiO2 thin films.
4. Preparation of TiO2 thin film by the LPD method on functionalized organic self-assembled monolayers
Institute of Scientific and Technical Information of China (English)
HE ZhongLiang; YU ZhiWei; MIAO HongYan; TAN GuoQiang; LIU Yan
2009-01-01
In this paper, uniform titania (TiO2) films have been formed at 50℃ on silanol SAMs by the liquid-phase deposition (LPD) method at a temperature below 100℃. OTS (Octadecyltrichloro-Silane) self-assembled monolayers (SAMs) on glass wafers were used as substrates for the deposition of titanium dioxide thin films. This functionalized organic surface has shown to be effective for promoting the growth of films from titanic aqueous solutions by the LPD method at a low temperature below 10012. The crystal phase composition, microstructure and topography of the as-prepared films were characterized by various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicate that the as-prepared thin films are purely crystallized anatase TiO2 constituted by nanorods after being annealed at 500℃. The pH values, concentration of reactants, and deposition temperatures play important roles in the growth of TiO2 thin films.
5. Method for Aluminum Oxide Thin Films Prepared through Low Temperature Atomic Layer Deposition for Encapsulating Organic Electroluminescent Devices
Directory of Open Access Journals (Sweden)
Hui-Ying Li
2015-02-01
Full Text Available Preparation of dense alumina (Al2O3 thin film through atomic layer deposition (ALD provides a pathway to achieve the encapsulation of organic light emitting devices (OLED. Unlike traditional ALD which is usually executed at higher reaction n temperatures that may affect the performance of OLED, this application discusses the development on preparation of ALD thin film at a low temperature. One concern of ALD is the suppressing effect of ambient temperature on uniformity of thin film. To mitigate this issue, the pumping time in each reaction cycle was increased during the preparation process, which removed reaction byproducts and inhibited the formation of vacancies. As a result, the obtained thin film had both high uniformity and density properties, which provided an excellent encapsulation performance. The results from microstructure morphology analysis, water vapor transmission rate, and lifetime test showed that the difference in uniformity between thin films prepared at low temperatures, with increased pumping time, and high temperatures was small and there was no obvious influence of increased pumping time on light emitting performance. Meanwhile, the permeability for water vapor of the thin film prepared at a low temperature was found to reach as low as 1.5 × 10−4 g/(m2·day under ambient conditions of 25 °C and 60% relative humidity, indicating a potential extension in the lifetime for the OLED.
6. Fabrication of water-stable organic transistors using crystalline rubrene thin-film and polymer-treated dielectric (Presentation Recording)
Science.gov (United States)
Kim, Jaejoon; Lee, Hyoek Moo; Cho, Sung Oh
2015-10-01
For the real application of organic electronics, stable operation of electronic devices in humid or aqueous condition is essential and desirable. However, most of organic semiconductors were very weak to the oxygen or water and especially, cannot be operated well in aqueous condition without an encapsulation. Here, we present water-stable organic thin-film transistors with highly crystallized rubrene and polymer-treated dielectrics. These high water-stability could be achieved by two factors. First, rubrene, a well-known p-type semiconducting material, showed high air and water stability after the crystallization of abrupt heating'. By the fabrication and aqueous operation of rubrene thin film transistor, we could show the water stability of crystallized thin-film rubrene. Such high environmental stability is attributed to the fact that rubrene has comparatively low HOMO level of -5.4 eV and large bandgap energy of 3.2 eV and that the rubrene thin-film is composed of well-interconnected orthorhombic rubrene crystals. Second, the polymer-treatment of dielectrics can enhance long-term water stability of fabricated rubrene thin-film transistor. By the complete immersion test of transistors, we could characterize the increase of water-stability after the treatment of dielectrics with cross-linked polymer. For this purpose, polystyrene is cross-linked by electron irradiation and the water penetration into semiconductor/dielectric interface was decreased due to the decreased surface energy of polymer dielectric compared to the SiO₂. The fabricated rubrene thin-film transistors showed a field-effect mobility of ~0.5 cm2V-1s-1 and long-term stability under ambient and aqueous conditions. Also, we investigated their potential applications in chemical or bio sensors.
7. Preparation of Titanium Oxide-containing Organic Film by Dipping Ti(OR)4 and Cold Plasma oxidizing on PET
International Nuclear Information System (INIS)
Low temperature process to prepare titanium oxide film on the surface of PET was investigated in this study. The substrates were pre-treated by oxygen plasma activated procedure, and then spin coating of Ti(OR)4 precursor solution was carried out to prepare Ti-containing organic films. Finally, O2 plasma was employed to decompose organic compounds and oxidize Ti to form oxides. Oxygen plasma post treatment can oxidize the organic compounds to form titanium oxide carbon subsequently. From the IR and ESCA analysis could be observed that -CH bond decreases and Ti-O, C-O bonds increase after O2 plasma treatment. Their surface hydrophilicity was enhanced by UV-irradiation, the degree of water contact angle decreased from 60 deg. to 10 deg.
8. A Boltzmann-weighted hopping model of charge transport in organic semicrystalline films
KAUST Repository
Kwiatkowski, Joe J.
2011-01-01
We present a model of charge transport in polycrystalline electronic films, which considers details of the microscopic scale while simultaneously allowing realistically sized films to be simulated. We discuss the approximations and assumptions made by the model, and rationalize its application to thin films of directionally crystallized poly(3-hexylthiophene). In conjunction with experimental data, we use the model to characterize the effects of defects in these films. Our findings support the hypothesis that it is the directional crystallization of these films, rather than their defects, which causes anisotropic mobilities. © 2011 American Institute of Physics.
9. Hybrid composite of screen-printed inorganic thermoelectric film and organic conducting polymer for flexible thermoelectric power generator
International Nuclear Information System (INIS)
TEG (Thermoelectric power generator) modules are attractive energy harvesters, as they can deliver electrical output power from the temperature difference of all sorts of things. Recently, growing interests in self-powered wearable mobile electronics provoke the necessity of flexible TEG modules. However, the technology on flexible TEG modules is still at a very early stage. Here we demonstrate flexible high-performance TEG modules using a screen-printed inorganic thermoelectric thick film and organic conducting polymer hybrid composite. By infiltrating the organic conducting polymer, poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), into the micropores of the screen-printed thermoelectric thick film, the flexibility of the module is greatly enhanced without degradation of the output characteristics of the module. This work provides a promising new approach which has the potential to achieve a flexible high-performance TEG module. - Highlights: • Hybrid composite of inorganic TE film and organic conducting polymer was prepared. • Addition of PEDOT:PSS to the TE film provided a 10% increment in the ZT value. • The flexible TEG module using the composite have successfully demonstrated. • The proposed method is simple, cheap, and mass-production friendly. • The strategy is applicable in self-powered wearable mobile electronics
10. Numerical Study on the Contribution of Convective Mass Transfer Inside High-Porosity Adsorbents in the VOC Adsorption Process
DEFF Research Database (Denmark)
Zhang, Ge; He, Wenna; Fang, Lei;
2013-01-01
The transfer mechanism of volatile organic compounds (VOCs) being trapped inside the various types of adsorbents is usually regarded as mere diffusion. This paper investigated the contribution of convective mass transfer inside the adsorbents used for VOC air-cleaning. The adsorbents are typicall...
11. Effect of titanium oxide–polystyrene nanocomposite dielectrics on morphology and thin film transistor performance for organic and polymeric semiconductors
International Nuclear Information System (INIS)
Previous studies have shown that organic thin film transistors with pentacene deposited on gate dielectrics composed of a blend of high K titanium oxide–polystyrene core–shell nanocomposite (TiO2–PS) with polystyrene (PS) perform with an order of magnitude increase in saturation mobility for TiO2–PS (K = 8) as compared to PS devices (K = 2.5). The current study finds that this performance enhancement can be translated to alternative small single crystal organics such as α-sexithiophene (α-6T) (enhancement factor for field effect mobility ranging from 30-100× higher on TiO2–PS/PS blended dielectrics as compared to homogenous PS dielectrics). Interestingly however, in the case of semicrystalline polymers such as (poly-3-hexylthiophene) P3HT, this dramatic enhancement is not observed, possibly due to the difference in processing conditions used to fabricate these devices (film transfer as opposed to thermal evaporation). The morphology for α-sexithiophene (α-6T) grown by thermal evaporation on TiO2–PS/PS blended dielectrics parallels that observed in pentacene devices. Smaller grain size is observed for films grown on dielectrics with higher TiO2–PS content. In the case of poly(3-hexylthiophene) (P3HT) devices, constructed via film transfer, morphological differences exist for the P3HT on different substrates, as discerned by atomic force microscopy studies. However, these devices only exhibit a modest (2×) increase in mobility with increasing TiO2–PS content in the films. After annealing of the transferred P3HT thin film transistor (TFT) devices, no appreciable enhancement in mobility is observed across the different blended dielectrics. Overall the results support the hypothesis that nucleation rate is responsible for changes in film morphology and device performance in thermally evaporated small molecule crystalline organic semiconductor TFTs. The increased nucleation rate produces organic polycrystalline films with small grain size which are
12. Methyl blue dyed polyethylene oxide films: Optical and electrochemical characterization and application as a single layer organic device
Science.gov (United States)
Kamath, Archana; Raghu, S.; Devendrappa, H.
2016-01-01
A single layer organic device employing methyl blue (MB) dyed polyethylene oxide (PEO) film has been fabricated and studied. The cyclic voltammetry was used to estimate the redox potential and energy band diagram of the device. The polymer film with highest concentration of the dye in PEO (PMB2%) possessing highest conductivity exhibited energy band gap of 2.62 eV with HOMO and LUMO values of 5.34 and 2.72 eV respectively. Based on cyclic voltammetry data, the electron affinity, ionization potential and energy band diagram of the device are discussed.
13. Krypton retention on solid adsorbents
International Nuclear Information System (INIS)
Radioactive krypton-85 is released to the atmosphere in the off-gas from nuclear reprocessing plants. Three main methods have been suggested for removal of krypton from off-gas streams: cryogenic distillation; fluorocarbon absorption; and adsorption on solid sorbents. Use of solid adsorbents is the least developed of these methods, but offers the potential advantages of enhanced safety and lower operating costs. An experimental laboratory program was developed that will be used to investigate systematically many solid adsorbents (such as zeolites, i.e., mordenites) for trapping krypton in air. The objective of this investigation is to find an adsorbent that is more economical than silver-exchanged mordenite. Various physical and chemical characteristics such as adsorption isotherms, decontamination factors, co-adsorption, regeneration, and the mechanism and kinetics of noble gas adsorption were used to characterize the adsorbents. In the experimental program, a gas chromatograph using a helium ionization detector was used to measure the krypton in air before and after the adsorbent bed. This method can determine directly decontamination factors greater than 100
14. The multiscale simulation of metal organic chemical vapor deposition growth dynamics of GaInP thin film
Institute of Scientific and Technical Information of China (English)
2010-01-01
As a Group III–V compound, GaInP is a high-efficiency luminous material. Metal organic chemical vapor deposition (MOCVD) technology is a very efficient way to uniformly grow multi-chip, multilayer and large-area thin film. By combining the computational fluid dynamics (CFD) and the kinetic Monte Carlo (KMC) methods with virtual reality (VR) technology, this paper presents a multiscale simulation of fluid dynamics, thermodynamics, and molecular dynamics to study the growth process of GaInP thin film in a vertical MOCVD reactor. The results of visualization truly and intuitively not only display the distributional properties of the gas’ thermal and flow fields in a MOCVD reactor but also display the process of GaInP thin film growth in a MOCVD reactor. The simulation thus provides us with a fundamental guideline for optimizing GaInP MOCVD growth.
15. Enhanced electrical properties of pentacene-based organic thin-film transistors by modifying the gate insulator surface
Science.gov (United States)
Tang, J. X.; Lee, C. S.; Chan, M. Y.; Lee, S. T.
2008-09-01
A reliable surface treatment for the pentacene/gate dielectric interface was developed to enhance the electrical transport properties of organic thin-film transistors (OTFTs). Plasma-polymerized fluorocarbon (CFx) film was deposited onto the SiO 2 gate dielectric prior to pentacene deposition, resulting in a dramatic increase of the field-effect mobility from 0.015 cm 2/(V s) to 0.22 cm 2/(V s), and a threshold voltage reduction from -14.0 V to -9.9 V. The observed carrier mobility increase by a factor of 10 in the resulting OTFTs is associated with various growth behaviors of polycrystalline pentacene thin films on different substrates, where a pronounced morphological change occurs in the first few molecular layers but the similar morphologies in the upper layers. The accompanying threshold voltage variation suggests that hole accumulation in the conduction channel-induced weak charge transfer between pentacene and CFx.
16. Structural and morphological evolution of cerium oxide thin film on silicon prepared by metal-organic decomposition route
International Nuclear Information System (INIS)
Thin film of cerium oxide (CeO2) were prepared on silicon (Si) substrate by metal organic decomposition route. 0.25 M of cerium (III) acetylacetonate (acac) was used as starting materials with the addition of methanol and acetic acid as solvents. Oxide conversion of the film by thermal treatment was conducted at temperature ranging from 400 degree Celsius to 1000 degree Celsius for 15 min in argon ambient. X-ray diffraction (XRD) analysis utilizing Cukα radiation (Model Brukker DiffracPlus), Filmetrics system measurement, field emission scanning electron microscope (FESEM) (Model Zeiss Supra 35 VP FESEM) and atomic force microscopy (AFM) (Model SII Nanonavi) were employed to characterize the phase formed and morphologies of the film produced. (author)
17. Evaluation of a cesium adsorbent grafted with ammonium 12-molybdophosphate
Science.gov (United States)
Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji
2016-02-01
A fibrous cesium (Cs) adsorbent was developed using radiation-induced graft polymerization with a cross-linked structure containing a highly stable adsorption ligand. The ligand, ammonium 12-molybdophosphate (AMP), was successfully introduced onto the fibrous polyethylene trunk material. The resulting Cs adsorbent contained 36% nonwoven fabric polyethylene (NFPE), 1% AMP, 2% triallyl isocyanurate (TAIC) and 61% glycidyl methacrylate (GMA). The adsorbent's Cs adsorption capacity was evaluated using batch and column tests. It was determined that the adsorbent could be used in a wide pH range. The amount of desorbed molybdenum, which can be used as an estimate for AMP stability on the Cs adsorbent, was minimized at the standard drinking water pH range of 5.8-8.6. Based from the inspection on the adherence of these results to the requirements set forth by the Food Sanitation Act by a third party organization, it can be concluded that the developed Cs adsorbent can be safely utilized for drinking water.
18. Titania nanotubes from weak organic acid electrolyte: fabrication, characterization and oxide film properties.
Science.gov (United States)
Munirathinam, Balakrishnan; Neelakantan, Lakshman
2015-04-01
In this study, TiO2 nanotubes were fabricated using anodic oxidation in fluoride containing weak organic acid for different durations (0.5h, 1h, 2h and 3h). Scanning electron microscope (SEM) micrographs reveal that the morphology of titanium oxide varies with anodization time. Raman spectroscopy and X-ray diffraction (XRD) results indicate that the as-formed oxide nanotubes were amorphous in nature, yet transform into crystalline phases (anatase and rutile) upon annealing at 600°C. Wettability measurements show that both as-formed and annealed nanotubes exhibited hydrophilic behavior. The electrochemical behavior was ascertained by DC polarization and AC electrochemical impedance spectroscopy (EIS) measurements in 0.9% NaCl solution. The results suggest that the annealed nanotubes showed higher impedance (10(5)-10(6)Ωcm(2)) and lower passive current density (10(-7)Acm(-2)) than the as-formed nanotubes. In addition, we investigated the influence of post heat treatment on the semiconducting properties of the oxides by capacitance measurements. In vitro bioactivity test in simulated body fluid (SBF) showed that precipitation of Ca/P is easier in crystallized nanotubes than the amorphous structure. Our study uses a simple strategy to prepare nano-structured titania films and hints the feasibility of tailoring the oxide properties by thermal treatment, producing surfaces with better bioactivity. PMID:25686985
19. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.
Science.gov (United States)
Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R
2016-11-01
A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide. PMID:27267693
20. Poly(3-Methylthiophene) Thin Films Deposited Electrochemically on QCMs for the Sensing of Volatile Organic Compounds.
Science.gov (United States)
Öztürk, Sadullah; Kösemen, Arif; Şen, Zafer; Kılınç, Necmettin; Harbeck, Mika
2016-01-01
Poly(3-methylthiophene) (PMeT) thin films were electrochemically deposited on quartz crystal microbalance QCM transducers to investigate their volatile organic compound (VOC) sensing properties depending on ambient conditions. Twelve different VOCs including alcohols, ketones, chlorinated compounds, amines, and the organosphosphate dimethyl methylphosphonate (DMMP) were used as analytes. The responses of the chemical sensors against DMMP were the highest among the tested analytes; thus, fabricated chemical sensors based on PMeT can be evaluated as potential candidates for selectively detecting DMMP. Generally, detection limits in the low ppm range could be achieved. The gas sensing measurements were recorded at various humid air conditions to investigate the effects of the humidity on the gas sensing properties. The sensing performance of the chemical sensors was slightly reduced in the presence of humidity in ambient conditions. While a decrease in sensitivity was observed for humidity levels up to 50% r.h., the sensitivity was nearly unaffected for higher humidity levels and a reliable detection of the VOCs and DMMP was possible with detection limits in the low ppm range. PMID:27023539 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5505123138427734, "perplexity": 7788.9754195651785}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560280310.48/warc/CC-MAIN-20170116095120-00189-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://vitalflux.com/quick-introduction-smoothing-techniques-language-models/ | Smoothing techniques in NLP are used to address scenarios related to determining probability / likelihood estimate of a sequence of words (say, a sentence) occuring together when one or more words individually (unigram) or N-grams such as bigram($$w_{i}$$/$$w_{i-1}$$) or trigram ($$w_{i}$$/$$w_{i-1}w_{i-2}$$) in the given set have never occured in the past.
In this post, you will go through a quick introduction to various different smoothing techniques used in NLP in addition to related formulas and examples. The following is the list of some of the smoothing techniques:
• Laplace smoothing: Another name for Laplace smoothing technique is add one smoothing.
• Good-turing smoothing
• Kneser-Ney smoothing
• Katz smoothing
• Church and Gale Smoothing
You will also quickly learn about why smoothing techniques to be applied. In the examples below, we will take the following sequence of words as corpus and test data set.
• Corpus (Training data): The following represents the corpus of words:
cats chase rats
cats meow
rats chatter
cats chase birds
rats sleep
• Test Data
rats chase birds
cats sleep
### Why Smoothing Techniques?
Based on the training data set, what is the probability of “cats sleep” assuming bigram technique is used? Based on bigram technique, the probability of the sequence of words “cats sleep” can be calculated as the product of following:
$$P(cats sleep) = P(\frac{cats}{<s>})\times P(\frac{sleep}{cats})\times P(\frac{</s>}{sleep})$$
You will notice that $$P(\frac{sleep}{cats}) = 0$$. Thus, the overall probability of occurrence of “cats sleep” would result in zero (0) value. However, the probability of occurrence of a sequence of words should not be zero at all.
This is where various different smoothing techniques come into the picture.
### Laplace (Add-One Smoothing)
In Laplace smoothing, 1 (one) is added to all the counts and thereafter, the probability is calculated. This is one of the most trivial smoothing techniques out of all the techniques.
Maximum likelihood estimate (MLE) of a word $$w_i$$ occuring in a corpus can be calculated as the following. N is total number of words, and $$count(w_{i})$$ is count of words for whose probability is required to be calculated.
MLE: $$P(w_{i}) = \frac{count(w_{i})}{N}$$
After applying Laplace smoothing, the following happens. Adding 1 leads to extra V observations.
MLE: $$P_{Laplace}(w_{i}) = \frac{count(w_{i}) + 1}{N + V}$$
Similarly, for N-grams (say, Bigram), MLE is calculated as the following:
$$P(\frac{w_{i}}{w_{i-1}}) = \frac{count(w_{i-1}, w_{i})}{count(w_{i-1})}$$
After applying Laplace smoothing, the following happens for N-grams (Bigram). Adding 1 leads to extra V observations.
MLE: $$P_{Laplace}(\frac{w_{i}}{w_{i-1}}) = \frac{count(w_{i-1}, w_{i}) + 1}{count(w_{i-1}) + V}$$
This is very similar to “Add One” or Laplace smoothing. Instead of adding 1 as like in Laplace smoothing, a delta($$\delta$$) value is added. Thus, the formula to calculate probability using additive smoothing looks like following:
$$P(\frac{w_{i}}{w_{i-1}}) = \frac{count(w_{i-1}, w_{i}) + \delta}{count(w_{i-1}) + \delta|V|}$$
### Good-Turing Smoothing
Good Turing Smoothing technique uses the frequencies of the count of occurrence of N-Grams for calculating the maximum likelihood estimate. For example, consider calculating the probability of a bigram (chatter/cats) from the corpus given above. Note that this bigram has never occurred in the corpus and thus, probability without smoothing would turn out to be zero. As per the Good-turing Smoothing, the probability will depend upon the following:
• In case, the bigram (chatter/cats) has never occurred in the corpus (which is the reality), the probability will depend upon the number of bigrams which occurred exactly one time and the total number of bigrams.
• In case, the bigram has occurred in the corpus (for example, chatter/rats), the probability will depend upon number of bigrams which occurred more than one time of the current bigram (chatter/rats) (the value is 1 for chase/cats), total number of bigram which occurred same time as the current bigram (to/bigram) and total number of bigram.
The following is the formula:
For the unknown N-grams, the following formula is used to calculate the probability:
$$P_{unknown}(\frac{w_{i}}{w_{i-1}}) = \frac{N_1}{N}$$
In above formula, $$N_1$$ is count of N-grams which appeared one time and N is count of total number of N-grams
For the known N-grams, the following formula is used to calculate the probability:
$$P(\frac{w_{i}}{w_{i-1}}) = \frac{c*}{N}$$
where c* = $$(c + 1)\times\frac{N_{i+1}}{N_{c}}$$
In the above formula, c represents the count of occurrence of n-gram, $$N_{c + 1}$$ represents count of n-grams which occured for c + 1 times, $$N_{c}$$ represents count of n-grams which occured for c times and N represents total count of all n-grams.
This video represents great tutorial on Good-turing smoothing.
### Kneser-Ney smoothing
In Good Turing smoothing, it is observed that the count of n-grams is discounted by a constant/abolute value such as 0.75. The same intuiton is applied for Kneser-Ney Smoothing where absolute discounting is applied to the count of n-grams in addition to adding the product of interpolation weight and probability of word to appear as novel continuation.
$$P_{Kneser-Ney}(\frac{w_{i}}{w_{i-1}}) = \frac{max(c(w_{i-1},w_{i} – d, 0))}{c(w_{i-1})} + \lambda(w_{i-1})*P_{continuation}(w_{i})$$
where $$\lambda$$ is a normalizing constant which represents probability mass that have been discounted for higher order. The following represents how $$\lambda$$ is calculated:
$$\lambda(w_{i-1}) = \frac{d\times|c(w_{i-1},w_{i})|}{c(w_{i-1})}$$
The following video provides deeper details on Kneser-Ney smoothing.
### Katz smoothing
Good-turing technique is combined with interpolation. Outperforms Good-Turing
by redistributing different probabilities to different unseen units.
### Church and Gale Smoothing
Good-turing technique is combined with bucketing.
• Each n-gram is assigned to one of serveral buckets based on its frequency predicted from lower-order models.
• Good-turing estimate is calculated for each bucket. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8473113179206848, "perplexity": 1828.6078954141199}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347439213.69/warc/CC-MAIN-20200604063532-20200604093532-00261.warc.gz"} |
http://math.stackexchange.com/questions/168786/how-to-approach-integrals-as-a-function/168832 | # How to approach integrals as a function?
I'm trying to solve the following question involving integrals, and can't quite get what am I supposed to do:
$$f(x) = \int_{2x}^{x^2}\root 3\of{\cos z}~dz$$ $$f'(x) =\ ?$$
How should I approach such integral functions? Am I just over-complicating a simple thing?
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Are you familiar with the Fundamental Theorem of Calculus and the chain rule for differentiation? – user17794 Jul 9 '12 at 20:35
Yes, I do; I tried messing with this integral around, using the Fundamental Theorem of Calculus, but wasn't quite sure I'm on the right path. I've ended up with a weird expression that I'm not sure is correct/final answer. I've tried gathering information from wolframalpha, but it doesn't seem to handle such functions/integrals. Could you direct me to the right way - what should I end with? – Dvir Azulay Jul 9 '12 at 20:40
@Sam: That looks interesting; Could you explain how it can be used here? – Dvir Azulay Jul 9 '12 at 20:41
You could first split the integral into two integrals: $\int_{2x}^{x^2} \root3\of{\cos z}\,dz =\int_{2x}^0\root3\of{\cos z}\,dz+\int_0^{x^2}\root3\of{\cos z}\,dz=-\int_0^{2x}\root3\of{\cos z}\,dz+\int_0^{x^2}\root3\of{\cos z}\,dz$, and then use Tim's hint in his comment. – David Mitra Jul 9 '12 at 20:52
For this problem, you will ultimately use a version of the Fundamental Theorem of Calculus: If $f$ is continuous, then the function $F$ defined by $F(x)=\int_a^x f(z)\,dz$ is differentiable and $F'(x)=f(x)$.
So for instance, for $F(x)=\int_0^x\root3\of{\cos z}\,dz$, we have $F'(x)=\root3\of{\cos x}$.
One can combine this with the chain rule, when it applies, to differentiate a function whose rule is of the form $F(x)=\int_a^{g(x)} f(z)\,dz$. Here, we recognize that $F$ is a composition of the form $F=G\circ g$ with $G(x)=\int_a^x f(z)\,dz$. The derivative is $F'(x)=\bigl[ G(g(x))\bigr]'=G'(g(x))\cdot g'(x)=f(g(x))\cdot g'(x)$.
For example, for $F(x)=\int_0^{x^2}\root3\of{\cos z}\,dz$, we have $F'(x)=\root3\of{\cos x^2}\cdot(x^2)'=2x\root3\of{\cos x^2}$.
Now to tackle your problem proper and take advantage of these rules, we just "split the integral": $$\tag{1} \int_{2x}^{x^2}\root3\of{\cos z}\,dz= \int_{2x}^{0}\root3\of{\cos z}\,dz+ \int_{0}^{x^2}\root3\of{\cos z}\,dz.$$ But wait! We can only use the aforementioned differentiation rules for functions defined by an integral when it's the upper limit of integration that is the variable. The first integral in the right hand side of $(1)$ does not satisfy this. Things are easily remedied, though; write the right hand side of $(1)$ as: $$-\int_{0}^{2x}\root3\of{\cos z}\,dz+ \int_{0}^{x^2}\root3\of{\cos z}\,dz;$$ and now things are set up to use our rule (of course, you'll also use the rule $[cf+g]'=cf'+g'$).
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Such a well written answer. Wish I could up-vote it a few more times; Thank you so much – Dvir Azulay Jul 9 '12 at 23:49
@dvir, I did it for you. – Tpofofn Jul 10 '12 at 2:38
Not to give it away completely. Using the Fundamental Theorem of Calculus, $f(x) = C(x^2)-C(2x)$, where $C(x)$ is the anti-derivative of the integrand. Now, use the Chain rule to compute $f'(x)$, which will depend only on the $C'(x)$, which is the integrand itself, evaluated at $x$.
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Really thanks for your answer! – Dvir Azulay Jul 9 '12 at 23:49
\begin{eqnarray} f'(x)&=&(x^2)'(\sqrt[s]{\cos z})|_{z=x^2}-(2x)'(\sqrt[s]{\cos z})|_{z=2x}\cr &=&2x\sqrt[s]{\cos x^2}-2\sqrt[s]{\cos 2x} \end{eqnarray}
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This doesn't seem correct. – Dom Jul 9 '12 at 21:49
Then show us what you think is correct! – Mercy Jul 9 '12 at 21:55
Shouldn't the answer be $2x\root s\of{\cos x^2} - 2\root s\of{\cos 2x}$ ? – Dom Jul 9 '12 at 22:03
Yes, you are right! – Mercy Jul 9 '12 at 22:13
Generally, to differentiate an integral of the form:
$$\int_{g_1(x)}^{g_2(x)}f(z)dz$$
we use Leibniz rule. First assume that $F(x)$ is the anti-derivative of $f(x)$. That is $F'(x) = f(x)$. Then it follows that,
$$\int_{g_1(x)}^{g_2(x)}f(z)dz = F(z)|_{z=g_2(x)} - F(z)|_{z=g_1(x)} = F(g_2(x)) - F(g_1(x))$$
Now if we differentiate this result using the chain rule we get:
$$\frac{d}{dx}\left(F(g_2(x)) - F(g_1(x))\right) = f(g_2(x))g_2'(x) - f(g_1(x))g_1'(x).$$
Note that it is not necessary to find the anti-derivative $F()$.
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Using the Leibnitz rule of differentiation of integrals, which states that if \begin{align} f(x) = \int_{a(x)}^{b(x)} g(y) \ dy, \end{align} then \begin{align} f^{\prime}(x) = g(b(x)) b^{\prime}(x) - g(a(x)) a^{\prime}(x). \end{align} Thus, for your problem $a^{\prime}(x) = 2$ and $b^{\prime}(x) = 2x$ and, therefore, \begin{align} f^{\prime}(x) = \int_{2x}^{x^2} \sqrt[3]{\cos z} dz = \sqrt[3]{\cos (x^2)} (2 x) - \sqrt[3]{\cos (2x)} (2). \end{align}
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The downvote seems a bit harsh. – user02138 Jul 16 '12 at 1:14 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 3, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9897775053977966, "perplexity": 546.8968645876398}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042988305.14/warc/CC-MAIN-20150728002308-00152-ip-10-236-191-2.ec2.internal.warc.gz"} |
http://dlmf.nist.gov/22.19 | # §22.19 Physical Applications
## §22.19(i) Classical Dynamics: The Pendulum
With appropriate scalings, Newton’s equation of motion for a pendulum with a mass in a gravitational field constrained to move in a vertical plane at a fixed distance from a fulcrum is
being the angular displacement from the point of stable equilibrium, . The bounded oscillatory solution of (22.19.1) is traditionally written
for an initial angular displacement , with at time 0; see Lawden (1989, pp. 114–117). The period is . The angle is a separatrix, separating oscillatory and unbounded motion. With the same initial conditions, if the sign of gravity is reversed then the new period is ; see Whittaker (1964, §44).
Alternatively, Sala (1989) writes:
for the initial conditions , the point of stable equilibrium for , and . Here is the energy, which is a first integral of the motion. This formulation gives the bounded and unbounded solutions from the same formula (22.19.3), for and , respectively. Also, is not restricted to the principal range . Figure 22.19.1 shows the nature of the solutions of (22.19.3) by graphing for both , as in Figure 22.16.1, and , where it is periodic.
Figure 22.19.1: Jacobi’s amplitude function for and . When , increases monotonically indicating that the motion of the pendulum is unbounded in , corresponding to free rotation about the fulcrum; compare Figure 22.16.1. As , plateaus are seen as the motion approaches the separatrix where , , at which points the motion is time independent for . This corresponds to the pendulum being “upside down” at a point of unstable equilibrium. For , the motion is periodic in , corresponding to bounded oscillatory motion.
## §22.19(ii) Classical Dynamics: The Quartic Oscillator
Classical motion in one dimension is described by Newton’s equation
where is the potential energy, and is the coordinate as a function of time . The potential
plays a prototypal role in classical mechanics (Lawden (1989, §5.2)), quantum mechanics (Schulman (1981, Chapter 29)), and quantum field theory (Pokorski (1987, p. 203), Parisi (1988, §14.6)). Its dynamics for purely imaginary time is connected to the theory of instantons (Itzykson and Zuber (1980, p. 572), Schäfer and Shuryak (1998)), to WKB theory, and to large-order perturbation theory (Bender and Wu (1973), Simon (1982)).
For real and positive, three of the four possible combinations of signs give rise to bounded oscillatory motions. We consider the case of a particle of mass 1, initially held at rest at displacement from the origin and then released at time . The subsequent position as a function of time, , for the three cases is given with results expressed in terms of and the dimensionless parameter .
### ¶ Case I:
This is an example of Duffing’s equation; see Ablowitz and Clarkson (1991, pp. 150–152) and Lawden (1989, pp. 117–119). The subsequent time evolution is always oscillatory with period :
### ¶ Case II:
There is bounded oscillatory motion near , with period , for initial displacements with :
As from below the period diverges since are points of unstable equilibrium.
### ¶ Case III:
Two types of oscillatory motion are possible. For an initial displacement with , bounded oscillations take place near one of the two points of stable equilibrium . Such oscillations, of period , are given by:
As from below the period diverges since is a point of unstable equlilibrium. For initial displacement with the motion extends over the full range :
with period . As from above the period again diverges. Both the and solutions approach as from the appropriate directions.
## §22.19(iii) Nonlinear ODEs and PDEs
Many nonlinear ordinary and partial differential equations have solutions that may be expressed in terms of Jacobian elliptic functions. These include the time dependent, and time independent, nonlinear Schrödinger equations (NLSE) (Drazin and Johnson (1993, Chapter 2), Ablowitz and Clarkson (1991, pp. 42, 99)), the Korteweg–de Vries (KdV) equation (Kruskal (1974), Li and Olver (2000)), the sine-Gordon equation, and others; see Drazin and Johnson (1993, Chapter 2) for an overview. Such solutions include standing or stationary waves, periodic cnoidal waves, and single and multi-solitons occurring in diverse physical situations such as water waves, optical pulses, quantum fluids, and electrical impulses (Hasegawa (1989), Carr et al. (2000), Kivshar and Luther-Davies (1998), and Boyd (1998, Appendix D2.2)).
## §22.19(iv) Tops
The classical rotation of rigid bodies in free space or about a fixed point may be described in terms of elliptic, or hyperelliptic, functions if the motion is integrable (Audin (1999, Chapter 1)). Hyperelliptic functions are solutions of the equation , where is a polynomial of degree higher than 4. Elementary discussions of this topic appear in Lawden (1989, §5.7), Greenhill (1959, pp. 101–103), and Whittaker (1964, Chapter VI). A more abstract overview is Audin (1999, Chapters III and IV), and a complete discussion of analytical solutions in the elliptic and hyperelliptic cases appears in Golubev (1960, Chapters V and VII), the original hyperelliptic investigation being due to Kowalevski (1889).
## §22.19(v) Other Applications
Numerous other physical or engineering applications involving Jacobian elliptic functions, and their inverses, to problems of classical dynamics, electrostatics, and hydrodynamics appear in Bowman (1953, Chapters VII and VIII) and Lawden (1989, Chapter 5). Whittaker (1964, Chapter IV) enumerates the complete class of one-body classical mechanical problems that are solvable this way. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9593717455863953, "perplexity": 1388.1863943890246}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368704933573/warc/CC-MAIN-20130516114853-00067-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://yufeizhao.wordpress.com/2012/04/ | ### Extremal results for sparse pseudorandom graphs
David Conlon, Jacob Fox and I have just uploaded to the arXiv our paper Extremal results in sparse pseudorandom graphs. The main advance of this paper is a sparse extension of the counting lemma associated to Szemerédi’s regularity lemma, allowing us to extend a wide range of classical extremal and Ramsey results to sparse pseudorandom graphs.
An important trend in modern combinatorics research is in extending classical results to the sparse setting. For instance, Szemerédi’s theorem says that every subset of the integers with positive density contains arbitrarily long arithmetic progressions. The celebrated result of Green and Tao says that the primes also contain arbitrarily long arithmetic progressions. While the primes have zero density in the integers, they may be placed inside a pseudorandom set of “almost primes” with positive relative density. Green and Tao established a transference principle, allowing them to apply Szemerédi’s theorem as a black box to the sparse setting. Our work has a similar theme. We establish a transference principle extending many classical extremal graph theoretic results to sparse pseudorandom graphs.
One of the most powerful tools in extremal graph theory is Szemerédi’s regularity lemma. Roughly speaking, it says that every large graph can be partitioned into a bounded number of roughly equally-sized parts so that the graph is random-like between pairs of parts. With this tool in hand, many important results in extremal graph theory can be proven using a three-step recipe, known as the regularity method:
1. Starting with any graph ${G}$, apply Szemerédi’s regularity lemma to obtain a regular partition;
2. Clean up the graph and create an associated reduced graph. Solve an easier problem in the reduced graph;
3. Apply the counting lemma. Profit.
The counting lemma is a result that says that the number of embeddings of a fixed graph (e.g., a triangle) into the regular partition is roughly what you would expect if the large graph were actually random. The original version of Szemerédi’s regularity lemma is useful only for dense graphs. Kohayakawa and Rödl later independently developed regularity lemmas for sparse graphs. However, for sparse extensions of the applications, the counting lemma remained a key missing ingredient and an important open problem in the field. Our main advance lies in a counting lemma that complements the sparse regularity lemma. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 1, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9216365814208984, "perplexity": 353.9783474501607}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583511175.9/warc/CC-MAIN-20181017132258-20181017153758-00466.warc.gz"} |
http://math.stackexchange.com/questions/268605/inequality-involving-roots-of-a-third-degree-polynomial | # Inequality involving roots of a third degree polynomial
Let $a,b$ be two positive numbers such that $a^3 \gt 27b$. Consider the polynomial
$$W(x)=x^3-2ax^2+a^2x-4b$$
Then we have
$$W(0)=-4b \lt 0, \ W(\frac{a}{3})=\frac{4}{27}(a^3-27b) \gt 0, \ W(a)=-4b \lt 0$$
We deduce that $W$ has three roots $\alpha,\beta,\gamma$ with
$$0 \lt \alpha \lt \frac{a}{3} \lt \beta \lt a \lt \gamma$$
Prove or find a counterexample : $2\alpha+\beta \leq a$.
-
What happens when you work out $W(2\alpha+\beta)$? – Gerry Myerson Jan 1 '13 at 13:48
@GerryMyerson : $W(2\alpha+\beta)$ is exactly $-6a^2\alpha + (8\alpha^2 + 4\beta\alpha)a + (8b + 6\beta\alpha^2)$, an expression whose sign is not obvious. So what ? – Ewan Delanoy Jan 1 '13 at 14:05
Sorry, just thought it might be worth a try. – Gerry Myerson Jan 1 '13 at 23:29
$W(\alpha + a)=a\, \alpha\,(3 \alpha-a)\leq 0$ so $\alpha + a \leq \gamma$. Together with $\alpha+\beta+\gamma=2a$ this implies that $2\alpha + \beta = 2a +\alpha-\gamma\leq a$.
@EwanDelanoy Quasi systematic at best. In this case I started with the last inequality and concluded that $\gamma-\alpha \geq a$ would suffice. Then I tried $W(\alpha + a)$ and got lucky. – WimC Jan 1 '13 at 15:30
by the way, I also the need the "reverse" inequality $a \leq \alpha+2\beta$. Because of your humiliatingly simple solution, I’ll try harder to find a proof for myself before asking it officially here. But if once again, a one-line proof leaps to your lucky eye, let me know, it might save me some trouble ... – Ewan Delanoy Jan 1 '13 at 15:48
@EwanDelanoy Note that $W(4a/3)>0$ so $\beta-\gamma\geq -a$. – WimC Jan 1 '13 at 16:00
How do you deduce $\beta - \gamma \geq -a$ from $W(\frac{4a}{3}) \gt 0$ ? – Ewan Delanoy Jan 1 '13 at 16:09 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9318791031837463, "perplexity": 678.2618346779944}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1429246639121.73/warc/CC-MAIN-20150417045719-00114-ip-10-235-10-82.ec2.internal.warc.gz"} |
https://forum.servoy.com/viewtopic.php?f=15&t=13974&start=15 | ## Plugin and Beans with Java 6 update 19
Questions and answers on developing, deploying and using plugins and JavaBeans
### Re: Plugin and Beans with Java 6 update 19
for 3.5 are you suggesting that a new build is needed. If so when will this be available?
Sorry, 80% of this is going above my head, as servoy 3.5 has always worked out of the box just by installing the plugins from whichever developer i have purchased them from. The whole situation is slightly worrying.
David
dpearce
Posts: 469
Joined: Sun Dec 03, 2006 11:53 am
### Re: Plugin and Beans with Java 6 update 19
ptalbot wrote:How will you know if they are? Will you check the jar and have 2 different classloaders?
I'm curious.
thats something i need to figure out...
on the server i could try to read out the file and see if it is signed. And if it is generate X and if it isnt generate Y
(this is only important for plugins without a jnlp and beans)
Plugins with a jnlp it simple, they generate there own jnlp and should if they sign use the all permissions entry else if they dont sign
then dont use that entry. So the problem is what to do with plugins (and beans) where we generate the jnlp for....
If they are signed then we need to use <all permissions> if they are not we cant generate that..
all plugins and beans are loaded through Class.forName() kind of syntax, we just need to give a right classloader with it (and i dont think this matters of it is signed or unsiged)
ptalbot wrote:Anyway, nice little tool you did, thanks.
I see that you have shipped a lot of java tools - including javac/javadoc/applet etc. - with it, why is that?
Its just the tools.jar of a java 6 install, added with 1 class and a manifest with a main attribute so it is very easy for people to use.
Didnt want to extract exactly what i needed because that is quite hard to find..
Johan Compagner
Servoy
jcompagner
Posts: 8309
Joined: Tue May 27, 2003 7:26 pm
Location: The Internet
### Re: Plugin and Beans with Java 6 update 19
What about beans that have dependencies? Right now, for the SVGBean for example, I add a dummy plugin with a jnlp to be able to load the batik jars, but of course these need to be signed, so I guess the safest approach is to sign the bean jar as well, isn't it?
I put a link to your post/tool on my FAQ for people who wants to sign the jars themselves.
Suggestion to Paul:
I think that you should put a permanent download link to this tool with the explanations somewhere (on the wiki perhaps?), because it will happen to people in the future and they will not know where to find the information buried in the forum.
Patrick Talbot
Freelance - Open Source - Servoy Valued Professional
http://www.servoy-stuff.net
https://www.servoyforge.net
--------------------------------------------
Servoy 5.2.16 / 6.0.9 / 6.1.6 / 7.3.1
All OSes / Java 5 & 6 & 7
ptalbot
Posts: 1616
Joined: Wed Mar 11, 2009 5:13 am
Location: Montreal, QC
### Re: Plugin and Beans with Java 6 update 19
if you have a bean that needs some external jars.
You dont need to also create a dummy plugin.
Just do it the bean way with adding the classpath manifest attribute and point to your 2 other jars there in the manifest of your bean.jar
Those external jars also need to be signed yes (with the same certificate!)
And in servoy 5.1.2 you will see that we generate a jnlp file for that bean that has 1 jar reference to your bean.jar and 1 or more jar references to the jar the bean jar depends on.
Johan Compagner
Servoy
jcompagner
Posts: 8309
Joined: Tue May 27, 2003 7:26 pm
Location: The Internet
### Re: Plugin and Beans with Java 6 update 19
jcompagner wrote:if you have a bean that needs some external jars.
You dont need to also create a dummy plugin.
Just do it the bean way with adding the classpath manifest attribute and point to your 2 other jars there in the manifest of your bean.jar
Those external jars also need to be signed yes (with the same certificate!)
And in servoy 5.1.2 you will see that we generate a jnlp file for that bean that has 1 jar reference to your bean.jar and 1 or more jar references to the jar the bean jar depends on.
If I add the external dependencies in a subfolder, with a classpath pointing on it, will it work?
For the SVGBean, the Batik framework is subdivised in 17 little jars (and I don't have them all), so if I put all this directly in /beans its going to be a big mess!
Patrick Talbot
Freelance - Open Source - Servoy Valued Professional
http://www.servoy-stuff.net
https://www.servoyforge.net
--------------------------------------------
Servoy 5.2.16 / 6.0.9 / 6.1.6 / 7.3.1
All OSes / Java 5 & 6 & 7
ptalbot
Posts: 1616
Joined: Wed Mar 11, 2009 5:13 am
Location: Montreal, QC
### Re: Plugin and Beans with Java 6 update 19
Hi everybody,
I'm trying to use signtester.jar to sign my jars. But it doesn't seem to work.
It seems to detect the unsigned jars but when I try to sign them using the keystore I have just created it doesn't seem to be able to sign them.
Here is an example (it's doing this for every jars):
Code: Select all
//signtester without parameter...Verifiying dir: .\plugins\it2be-outlookC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-outlook.jar didnt verifyC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-splash.jar didnt verifyC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-tools.jar didnt verify...//signtester with keystore in parameter...Verifiying dir: .\plugins\it2be-outlookC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-outlook.jar didnt verifyC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-outlook.jar still not signed, is it double signed?C:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-splash.jar didnt verifyC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-splash.jar still not signed, is it double signed?C:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-tools.jar didnt verifyC:\Program Files (x86)\Servoy\application_server\.\plugins\it2be-tools.jar still not signed, is it double signed?...
Did I forget something?
Current configuration: Servoy 5.2.6 Build 1011, Java 6u24, PostgreSQL 8.3, Windows Server 2003
Servoy / Java Developer
http://www.assetguardian.com
Foobrother
Posts: 530
Joined: Tue Jan 13, 2009 5:46 pm
### Re: Plugin and Beans with Java 6 update 19
it could be that those are double signed or something now.
For those you have to remove the signing out of the jar file your self
This means deleting the 2 files in \META-INF\ that ends with .rsa and .sf
and then update the manifest.mf deleting all the lines with:
Name: xxx.class name (or other resource)
SHA1-Digest: XXXXXX
with plugins this mostly means from the first line that that is starting you can delete everything from there to the end
With beans you have to be more careful because there you can have a Name: xxx entry that also has a line:
Java-Bean: True
then the name:xxx must be kept including the java-bean and only the SHA1 can be removed.
But maybe the easiest thing to do is to wait for it2be to give you its updated plugins
I think that is pretty much done.
Johan Compagner
Servoy
jcompagner
Posts: 8309
Joined: Tue May 27, 2003 7:26 pm
Location: The Internet
### Re: Plugin and Beans with Java 6 update 19
I run into that too, and it has nothing to do with double signing (althought it could):
You need to do that WHEN SERVOY IS NOT running, I don't think this is obvious for people, if you do it while the server/developer is running the jars are locked (at least on windows)!
Patrick Talbot
Freelance - Open Source - Servoy Valued Professional
http://www.servoy-stuff.net
https://www.servoyforge.net
--------------------------------------------
Servoy 5.2.16 / 6.0.9 / 6.1.6 / 7.3.1
All OSes / Java 5 & 6 & 7
ptalbot
Posts: 1616
Joined: Wed Mar 11, 2009 5:13 am
Location: Montreal, QC
### Re: Plugin and Beans with Java 6 update 19
ptalbot was right. When I tried I still had the server running.
Now it seems to have signed everything and when I run a check again no jar is highlighted as "not signed".
However, after clearing my cache, when I try to connected I still have the error message with the swingbeans.jar bean. And when I look on the server under the beans folder I see that swingbeans.jar has not been changed (last modification date didn't change).
Current configuration: Servoy 5.2.6 Build 1011, Java 6u24, PostgreSQL 8.3, Windows Server 2003
Servoy / Java Developer
http://www.assetguardian.com
Foobrother
Posts: 530
Joined: Tue Jan 13, 2009 5:46 pm
### Re: Plugin and Beans with Java 6 update 19
But swing beans cant really be signed at least there is not really something to sign (there are no classes)
But Servoy 5.1.2 will not serve out the swingbeans.jar (or any jar like that like it2be calendar bean) to the client
So your smart client shouldnt get that one at all.
What is the contents of the generated file (so the source of http://localhost:8080/servoy-client/servoy_client.jnlp)?
in that you shouldnt see swingbeans.jar
So yes my tool skips over those with the same logic as the app server does for generating the jnlp files.
Johan Compagner
Servoy
jcompagner
Posts: 8309
Joined: Tue May 27, 2003 7:26 pm
Location: The Internet
### Re: Plugin and Beans with Java 6 update 19
To make it clear, we are currently running on Servoy 5.1.1 and need to fix it with this version or earlier as we have customers still running on 4.1.4.
So if your tool skips jars like swingbeans.jar, yes it's normal that we still have a problem it.
Here is the content of the launch file:
Code: Select all
<?xml version="1.0" encoding="utf-8"?><jnlp spec="1.0+" codebase="http://ag-dev:8080" href="/servoy-client/servoy_client/EPiC.jnlp"> <information> <title>Servoy Client - EPiC</title> <vendor>Elite Control Systems Limited</vendor> <homepage href="http://www.servoy.com/"/> <description>Database client</description> <icon href="/lib/images/AssetGuardian.png"/> <icon kind="splash" href="//lib/AssetGuardian.png" width="64" height="64"/> </information> <resources> <j2se version="1.5+" initial-heap-size="128m" max-heap-size="512m" java-vm-args="-XX:SoftRefLRUPolicyMSPerMB=3600000" /> <j2se version="1.6+" initial-heap-size="128m" max-heap-size="512m" java-vm-args="-XX:SoftRefLRUPolicyMSPerMB=3600000" /> <property name="apple.laf.useScreenMenuBar" value="true"/> <jar href="/lib/j2db.jar" main="true" version="1269425007271" download="eager"/> <jar href="/lib/js.jar" version="1269425007271" download="eager"/> <jar href="/lib/jabsorb.jar" version="1269425007271" download="eager"/> <jar href="/lib/BrowserLauncher2.jar" version="1269425007271" download="eager"/> <jar href="/lib/commons-logging.jar" version="1269425007271" download="eager"/> <jar href="/lib/MRJAdapter.jar" version="1269425007271" download="eager"/> <extension name="LAFS_and_BEANS" href="/servoy-client/unsigned.jnlp" version="1271161582293"/> <extension name="excelxport.jar" href="/servoy-client/plugins/excelxport.jar.jnlp" version="1271161563710"/> <extension name="it2be-tools.jar" href="/servoy-client/plugins/it2be-tools.jar.jnlp" version="1271161565602"/> <extension name="udp.jar" href="/servoy-client/plugins/udp.jar.jnlp" version="1271161581828"/> <extension name="default_validators.jar" href="/servoy-client/plugins/default_validators.jar.jnlp" version="1271161563636"/> <extension name="tabxport.jar" href="/servoy-client/plugins/tabxport.jar.jnlp" version="1271161581798"/> <extension name="amortization.jar" href="/servoy-client/plugins/amortization.jar.jnlp" version="1271161563572"/> <extension name="servoyguy_spellcheck_pro.jar" href="/servoy-client/plugins/servoyguy_spellcheck_pro.jar.jnlp" version="1271161573047"/> <extension name="spellcheck.jar" href="/servoy-client/plugins/spellcheck.jar.jnlp" version="1271161581758"/> <extension name="dialog.jar" href="/servoy-client/plugins/dialog.jar.jnlp" version="1271161563664"/> <extension name="it2be-splash.jar" href="/servoy-client/plugins/it2be-splash.jar.jnlp" version="1271161565558"/> <extension name="scheduler.jar" href="/servoy-client/plugins/scheduler.jar.jnlp" version="1271161572962"/> <extension name="it2be-outlook.jar" href="/servoy-client/plugins/it2be-outlook.jar.jnlp" version="1271161565500"/> <extension name="it2be-datastream.jar" href="/servoy-client/plugins/it2be-datastream.jar.jnlp" version="1271161565274"/> <extension name="images.jar" href="/servoy-client/plugins/images.jar.jnlp" version="1271161564826"/> <extension name="file.jar" href="/servoy-client/plugins/file.jar.jnlp" version="1271161563759"/> <extension name="servoy_jasperreports.jar" href="/servoy-client/plugins/servoy_jasperreports.jar.jnlp" version="1271161581626"/> <extension name="maintenance.jar" href="/servoy-client/plugins/maintenance.jar.jnlp" version="1271161571713"/> <extension name="serialize.jar" href="/servoy-client/plugins/serialize.jar.jnlp" version="1271161572994"/> <extension name="agent.jar" href="/servoy-client/plugins/agent.jar.jnlp" version="1271161563521"/> <extension name="http.jar" href="/servoy-client/plugins/http.jar.jnlp" version="1271161563840"/> <extension name="window.jar" href="/servoy-client/plugins/window.jar.jnlp" version="1271161581946"/> <extension name="converters.jar" href="/servoy-client/plugins/converters.jar.jnlp" version="1271161563606"/> <extension name="rawSQL.jar" href="/servoy-client/plugins/rawSQL.jar.jnlp" version="1271161572684"/> <extension name="it2be-word.jar" href="/servoy-client/plugins/it2be-word.jar.jnlp" version="1271161566102"/> <extension name="pdf_output.jar" href="/servoy-client/plugins/pdf_output.jar.jnlp" version="1271161572654"/> <extension name="mail.jar" href="/servoy-client/plugins/mail.jar.jnlp" version="1271161571684"/> <extension name="xmlreader.jar" href="/servoy-client/plugins/xmlreader.jar.jnlp" version="1271161582001"/> <extension name="headlessclient.jar" href="/servoy-client/plugins/headlessclient.jar.jnlp" version="1271161563800"/> </resources> <application-desc main-class="com.servoy.j2db.J2DBClient"> <argument>CI:83664CC2-EE7B-455A-9174-8DA1205A039F</argument> <argument>s:EPiC</argument> <argument>solution:EPiC</argument> </application-desc> <security> <all-permissions/> </security></jnlp>
Current configuration: Servoy 5.2.6 Build 1011, Java 6u24, PostgreSQL 8.3, Windows Server 2003
Servoy / Java Developer
http://www.assetguardian.com
Foobrother
Posts: 530
Joined: Tue Jan 13, 2009 5:46 pm
### Re: Plugin and Beans with Java 6 update 19
The tool works only in conjunction with Servoy 5.1.2 and 4.1.6 (and upcomming 3.5.11)
Jan Blok
Servoy
Jan Blok
Posts: 2684
Joined: Mon Jun 23, 2003 11:15 am
Location: Amsterdam
### Re: Plugin and Beans with Java 6 update 19
Jan Blok wrote:The tool works only in conjunction with Servoy 5.1.2 and 4.1.6 (and upcomming 3.5.11)
So the best solution for people who cannot upgrade Servoy quickly and have Java 6 Update 19 or more on their machine, is to downgrade to update 18 and wait for the update of Servoy to be done?
Current configuration: Servoy 5.2.6 Build 1011, Java 6u24, PostgreSQL 8.3, Windows Server 2003
Servoy / Java Developer
http://www.assetguardian.com
Foobrother
Posts: 530
Joined: Tue Jan 13, 2009 5:46 pm
### Re: Plugin and Beans with Java 6 update 19
If you cannot upgrade Servoy to the latest version, yes you have to install a Java lower then Java 6u19.
Foobrother wrote:and wait for the update of Servoy to be done?
We released 5.1.2 and 4.1.6 already, last week...as a response to Sun's unannounced security level change.
Jan Blok
Servoy
Jan Blok
Posts: 2684
Joined: Mon Jun 23, 2003 11:15 am
Location: Amsterdam
### Re: Plugin and Beans with Java 6 update 19
Jan Blok wrote:If you cannot upgrade Servoy to the latest version, yes you have to install a Java lower then Java 6u19.
Foobrother wrote:and wait for the update of Servoy to be done?
We released 5.1.2 and 4.1.6 already, last week...as a response to Sun's unannounced security level change.
I was just asking if the best solution was to stay on/downgrade to update 18 until an admin installs the Servoy update.
I know you guys have quickly released a new version to fix this issue and I thank you for that. But I was just wondering If there was a solution for people who cannot install Servoy update quickly (we have customers who need 2 months to run security tests procedures to allow an update on their production servers)
Current configuration: Servoy 5.2.6 Build 1011, Java 6u24, PostgreSQL 8.3, Windows Server 2003
Servoy / Java Developer
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Foobrother
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PreviousNext | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.29244112968444824, "perplexity": 19252.289678581965}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439737152.0/warc/CC-MAIN-20200807025719-20200807055719-00243.warc.gz"} |
https://www.gradesaver.com/textbooks/science/physics/university-physics-with-modern-physics-14th-edition/chapter-10-dynamics-of-rotational-motion-problems-exercises-page-335/10-76 | ## University Physics with Modern Physics (14th Edition)
(a) $\omega = 1.28~rad/s$ (b) $\omega = 0.631~rad/s$ (c) $h = 1.26~m$
We can find the moment of inertia of the vine when Jane is swinging on it. $I = \frac{1}{3}M_vR^2+M_jR^2$ $I = \frac{1}{3}(30.0~kg)(8.00~m)^2+(60.0~kg)(8.00~m)^2$ $I = 4480~kg~m^2$ We can use conservation of energy to find the angular speed at the bottom. Note that the center of mass of the vine drops a height of 2.50 meters when Jane falls 5.00 meters. $\frac{1}{2}I\omega^2 = M_j~gh+M_v~g(\frac{h}{2})$ $\omega^2 = \frac{2M_j~gh+M_v~gh}{I}$ $\omega = \sqrt{\frac{2M_j~gh+M_v~gh}{I}}$ $\omega = \sqrt{\frac{(2)(60.0~kg)(9.80~m/s^2)(5.00~m)+(30.0~kg)(9.80~m/s^2)(5.00~m)}{4480~kg~m^2}}$ $\omega = 1.28~rad/s$ (b) We can find the moment of inertia when Tarzan is included. $I = \frac{1}{3}M_vR^2+(M_j+M_t)R^2$ $I = \frac{1}{3}(30.0~kg)(8.00~m)^2+(60.0~kg+72.0~kg)(8.00~m)^2$ $I = 9088~kg~m^2$ We can use conservation of angular momentum to find the angular speed after Jane grabs Tarzan. $L_2=L_1$ $I_2\omega_2=I_1\omega_1$ $\omega_2=\frac{I_1\omega_1}{I_2}$ $\omega_2=\frac{(4480~kg~m^2)(1.28~rad/s)}{9088~kg~m^2}$ $\omega_2 = 0.631~rad/s$ (c) We can use conservation of energy to find the maximum height that Jane and Tarzan swing up. Note that the center of mass of the vine rises a height of $\frac{h}{2}$ meters when Jane rises $h$ meters. $(M_j+M_t)~gh+M_v~g(\frac{h}{2}) = \frac{1}{2}I_2\omega_2^2$ $(M_j+M_t)~2gh+M_v~gh = I_2\omega_2^2$ $h = \frac{I_2\omega_2^2}{(M_j+M_t)~2g+M_v~g}$ $h = \frac{(9088~kg~m^2)(0.631~rad/s)^2}{(60.0~kg+72.0~kg)(2)(9.80~m/s^2)+(30.0~kg)(9.80~m/s^2)}$ $h = 1.26~m$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9812091588973999, "perplexity": 196.28672091538206}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039742483.3/warc/CC-MAIN-20181115033911-20181115055911-00483.warc.gz"} |
https://tex.stackexchange.com/questions/154373/baselineskip-ignored-in-beamer-footline | # Baselineskip ignored in Beamer footline [duplicate]
I am using the following to define the footline element of my Beamer presentation:
\setbeamerfont{footline}{size=\large}
\defbeamertemplate*{footline}{Institute} %the fontsize changes the size of the footer
{
\center{\color{algrey}{\noindent\hspace{0cm}\rule[0cm]{\paperwidth}{1pt}}}\\
\leavevmode%
% \vspace{0.4cm}
\begin{beamercolorbox}[sep=.5em,wd=\paperwidth,ht=4.90ex,dp=1ex,center]{innerbox}%
% FAU Logo
%\begin{picture}(100.0,0.0)
% \put(290.7,-9.85){\includegraphics[height=0.7cm]{templates/logos/logo_dummy}}
% \end{picture}
\begin{beamercolorbox}[wd=0.400\paperwidth,ht=2ex,dp=0ex,left]{innerbox}%
{\setstretch{10.0}\fontsize{5}{10}\selectfont \inserttitle \\[4pt] \insertauthor \par}
\end{beamercolorbox}
\begin{beamercolorbox}[wd=1.1cm,ht=2ex,dp=0ex,center]{innerbox}%
\end{beamercolorbox}
% Page Counter
\begin{beamercolorbox}[wd=0.425\paperwidth,ht=1ex,dp=0ex,right]{innerbox}%
%{\large Institute}\\
\vspace{-0.19cm}
\includegraphics[height=0.7cm]{templates/logos/logo_dummy}
% \vspace{-0.5pt}
\end{beamercolorbox}
\end{beamercolorbox}
}
This results in a footer rendered as:
As you can see, the title lines have no whitespace (baselineskip) between them. I tried to
• set \fontsize{x}{y}\selectfont to different values
• manually set \baselineskip
• change \setbeamerfont{footline}{size=\large}
• change the size of the beamercolorboxes
however nothing helped separating the two title lines.
## marked as duplicate by Ignasi, user13907, Jesse, user31729, Claudio FiandrinoNov 14 '14 at 10:44
The issue is adressed at https://tex.stackexchange.com/a/179255 and can be resolved by adding \normalbaselines to the code of the footline. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8084511756896973, "perplexity": 24297.884989200094}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195527531.84/warc/CC-MAIN-20190722051628-20190722073628-00473.warc.gz"} |
http://mathhelpforum.com/pre-calculus/205439-inequality.html | 1. ## Inequality
Let $x,y,z \in R$ such that $x^2+y^2+z^2=1$. Prove $|x+y+z| \leq \sqrt{3}$. I thinking along the lines of $AGM \leq GM$.
2. ## Re: Inequality
Originally Posted by brucewayne
Let $x,y,z \in R$ such that $x^2+y^2+z^2=1$.
Prove $|x+y+z| \leq \sqrt{3}$.
Here are the facts you need.
$2|xy|\le x^2+y^2$
$|x+y+z|^2\le (|x|+|y|+|z|)^2=x^2+y^2+z^2+2|xy|+2|xz|+2|yz|$
3. ## Re: Inequality
Ok, I am heading in the right direction...
$1+2x^2+2y^2+2z^2 \leq \sqrt{3}$
4. ## Re: Inequality
Originally Posted by brucewayne
Ok, I am heading in the right direction...
$1+2x^2+2y^2+2z^2 \leq \sqrt{3}$
Factor out the 2 in the last three terms.
You have
$|x+y+z|^2\le 3$
5. ## Re: Inequality
Ok, Maybe I am missing something, but what happened to 1?
6. ## Re: Inequality
Originally Posted by brucewayne
Ok, Maybe I am missing something, but what happens to 1?
Come man do basic mathamatics.
$1+2x^2+2y^2+2z^2=1+2(x^2+y^2+z^2)=1+2(1)=3$
7. ## Re: Inequality
Dang it, I really do over analyze things at times. My sincerest apologies; I am trying to get better at this. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 13, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9248746037483215, "perplexity": 2576.793765530699}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084890874.84/warc/CC-MAIN-20180121195145-20180121215145-00342.warc.gz"} |
https://arxiv.org/abs/1409.1149 | quant-ph
# Title:Nearby states in non-Hermitian quantum systems
Abstract: In part I, the formalism for the description of open quantum systems (that are embedded into a common well-defined environment) by means of a non-Hermitian Hamilton operator $\ch$ is sketched. Eigenvalues and eigenfunctions are parametrically controlled. Using a 2$\times$2 model, we study the eigenfunctions of $\ch$ at and near to the singular exceptional points (EPs) at which two eigenvalues coalesce and the corresponding eigenfunctions differ from one another by only a phase. In part II, we provide the results of an analytical study for the eigenvalues of three crossing states. These crossing points are of measure zero. Then we show numerical results for the influence of a nearby ("third") state onto an EP. Since the wavefunctions of the two crossing states are mixed in a finite parameter range around an EP, three states of a physical system will never cross in one point. Instead, the wavefunctions of all three states are mixed in a finite parameter range in which the ranges of the influence of different EPs overlap. We may relate these results to dynamical phase transitions observed recently in different experimental studies. The states on both sides of the phase transition are non-analytically connected.
Comments: Change of the title; Partition into two parts; Published in Eur. Phys. J. D 69, 229 (2015) and D 69, 230 (2015) Subjects: Quantum Physics (quant-ph) DOI: 10.1140/epjd/e2015-60389-7 Cite as: arXiv:1409.1149 [quant-ph] (or arXiv:1409.1149v3 [quant-ph] for this version)
## Submission history
From: Ingrid Rotter [view email]
[v1] Wed, 3 Sep 2014 16:28:49 UTC (1,694 KB)
[v2] Mon, 6 Oct 2014 16:27:42 UTC (1,695 KB)
[v3] Fri, 16 Oct 2015 14:34:45 UTC (1,867 KB) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7481051683425903, "perplexity": 1143.9796582208571}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987826436.88/warc/CC-MAIN-20191022232751-20191023020251-00357.warc.gz"} |
http://math.stackexchange.com/questions/174616/how-high-will-the-water-rise | # How high will the water rise
I need to know where I am going wrong since I am getting the wrong answer
12 litres of water are poured into an aquarium of $50$ cm length , $30$ cm breadth and $40$ cm Height.How high in cm will the water rise. (Ans 8 cm)
Edit: So I was making some very illogical assumptions however according to advice given which suggested that I keep the changing dimension value variable I got the answer which is
$1000cm^3$ = $50 \times 30 \times x$ so $x = \frac{1000}{1500}$. so $1$ litre has height $\frac{1000}{1500} = \frac {2}{3}$ so $12$ litres will give $12 \times \frac{2}{3} = 8 cm$
-
I think a good start would be to ask whatever led you to write $50\times30\times40=5\times3\times4$ when it's patently not so. – Gerry Myerson Jul 24 '12 at 10:53
I agree that does not make sense – MistyD Jul 24 '12 at 10:55
Tips on solving this problem ? – MistyD Jul 24 '12 at 10:56
Which dimension (length, breadth, height) changes when you pour in the water? This is where the $x$ should go. The other two stay constant, so you have $x\cdot C_1 \cdot C_2$, which should match $12\;l$. To make the match, you have to convert litres to $cm^3$... – draks ... Jul 24 '12 at 10:56
how did you get $12l$ ? – MistyD Jul 24 '12 at 11:01 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.857846736907959, "perplexity": 571.2026760935028}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207926924.76/warc/CC-MAIN-20150521113206-00101-ip-10-180-206-219.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/a-de-sitter-like-universe-with-matter.521084/ | # A de Sitter like Universe with matter
1. Aug 12, 2011
### johne1618
As I understand it the de Sitter model is a model of the Universe with:
rho = matter density = rho = 0
p = pressure = 0
k = spatial curvature = 0
cosmological constant = Lambda = non zero
Putting these values in the Friedmann equations one finds the solution for the scale factor a(t) is:
a(t) = exp( sqrt(Lambda c^2/3) * t)
This describes an accelerating empty universe with a non-zero cosmological constant.
Although this model has the right deceleration parameter q = -1 it is contrary to observations as we know there is matter in the Universe.
Now consider the following model:
p = - rho c^2
k = 0
Plugging these values into the Friedmann equations we find we are left with the following equation for the scale factor a:
a'^2 = a a''
This also has the solution:
a(t) = exp(H * t)
where
H^2 = 8 Pi G rho' / 3
where rho' = rho + Lambda c^2
Now this model describes a matter-filled accelerating Universe with no explicit cosmological constant provided that the equation of state of the matter is:
p = -rho c^2
Is this right?
Does this latter model describe the present Universe provided that p = -rho c^2 holds for present day matter?
In this model the negative pressure is associated with the particles of matter themselves rather than having a cosmological constant that is associated with the background space.
Perhaps the negative pressure is a zero-point energy phenomenon holding the individual particles of matter together (in the same manner as the Casimir effect pushes conducting plates together).
Last edited: Aug 12, 2011
2. Aug 12, 2011
### IsometricPion
The http://en.wikipedia.org/wiki/Einstein_field_equations" [Broken].
Last edited by a moderator: May 5, 2017
3. Aug 13, 2011
### Chalnoth
There's no difference between an empty universe with a cosmological constant and a universe that is filled only with matter that has negative pressure equal to its energy density. They are just two different ways of describing the same thing.
Just bear in mind that our own universe has quite a bit of normal matter that has no pressure on cosmological scales.
4. Aug 13, 2011
### johne1618
Maybe each baryon of normal and dark matter is held together by the excess pressure of zero-point gluon fields outside the particle. Thus there would be a region of negative pressure hiding inside every baryon in the Universe.
Last edited: Aug 13, 2011
5. Aug 13, 2011
### Chalnoth
But then matter wouldn't collapse and form structures.
6. Aug 13, 2011
### johne1618
Good point - I'll have to think about that one! | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8942152261734009, "perplexity": 1375.8378194709314}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267861641.66/warc/CC-MAIN-20180619002120-20180619022120-00037.warc.gz"} |
https://brainiak.in/3724/what-disadvantages-fossil-fuels | # What are the disadvantages of fossil fuels?
What are the disadvantages of fossil fuels?
verified
The disadvantages of fossil fuels are:
• Burning of coal and petroleum produces a lot of pollutants causing air pollution.
• Fossil fuels release oxides of carbon, nitrogen, sulphur, etc. that cause acid rain, which affects the soil fertility and potable water.
• Burning of fossil fuels produce gases such as carbon dioxide that causes global warming. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8721838593482971, "perplexity": 5245.84413099228}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320301263.50/warc/CC-MAIN-20220119033421-20220119063421-00444.warc.gz"} |
https://www.birthdaycelebs.com/category/people/?filter_by=featured | # People
People
### ZWG
ZWG (YouTube Star ) was born in Poland on a , , . ZWG is years old. He is a and...
### Zz Ward
Zz Ward (Blues Singer ) was born in Abington on a , , . Zz Ward is years old. She is a ...
### ZybakTV
ZybakTV (YouTube Star ) was born in United States on a , , . ZybakTV is years old. He is a ...
### Zydrunas Ilgauskas
Zydrunas Ilgauskas (Basketball Player ) was born in Kaunas on a , , . Zydrunas Ilgauskas is years old. He is a ...
### Zydrunas Savickas
Zydrunas Savickas (Bodybuilder ) was born in Lithuania on a , , . Zydrunas Savickas is years old. He is a ...
### Zygmunt Szczesny Felinski
Zygmunt Szczesny Felinski (Religious Leader ) was born in Ukraine on a , , . Zygmunt Szczesny Felinski is years old. He is...
### Zyl
Zyl (Stylist ) was born in United States on a , , . Zyl is years old. She is a and...
### Zyler the Cat
Zyler the Cat (Cat ) was born in Canada on a , , . Zyler the Cat is years old. He is a...
### Zylus
Zylus (YouTube Star ) was born in Netherlands on a , , . Zylus is years old. He is a and...
### Zymic Jaranilla
Zymic Jaranilla (Movie Actor ) was born in Philippines on a , , . Zymic Jaranilla is years old. He is a ... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8147775530815125, "perplexity": 19181.215002066718}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496669422.96/warc/CC-MAIN-20191118002911-20191118030911-00465.warc.gz"} |
http://philpapers.org/s/causality | ## Search results for 'causality' (try it on Scholar)
1000+ found
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1. score: 24.0
I argue that Berkeley's distinctive idealism/immaterialism can't support his view that objects of sense, immediately or mediately perceived, are causally inert. (The Passivity of Ideas thesis or PI) Neither appeal to ordinary perception, nor traditional arguments, for example, that causal connections are necessary, and we can't perceive such connections, are helpful. More likely it is theological concerns,e.g., how to have second causes if God upholds by continuously creating the world, that's in the background. This puts Berkeley closer to Malebranche than (...)
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2. Wesley C. Salmon (1998). Causality and Explanation. Oxford University Press.score: 24.0
Wesley Salmon is renowned for his seminal contributions to the philosophy of science. He has powerfully and permanently shaped discussion of such issues as lawlike and probabilistic explanation and the interrelation of explanatory notions to causal notions. This unique volume brings together twenty-six of his essays on subjects related to causality and explanation, written over the period 1971-1995. Six of the essays have never been published before and many others have only appeared in obscure venues. The volume includes a (...)
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3. Justin Remhof (forthcoming). Naturalism, Causality, and Constructivism in Nietzsche?S Conception of Science. Journal of Nietzsche Studies.score: 24.0
There is a puzzle over how to understand Nietzsche?s view of science. According to what I call the Skeptical View, Nietzsche thinks science should be reconceived or superseded by another discourse, such as art, because it is nihilistic. By contrast, what call the Positive View holds that Nietzsche does not think science is nihilistic, so he denies that it should be reinterpreted or overcome. Interestingly, defenders of each position appeal to Nietzsche?s understanding of naturalism to support their interpretation. This essay (...)
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4. Travis Norsen (2009). Local Causality and Completeness: Bell Vs. Jarrett. [REVIEW] Foundations of Physics 39 (3):273-294.score: 24.0
J.S. Bell believed that his famous theorem entailed a deep and troubling conflict between the empirically verified predictions of quantum theory and the notion of local causality that is motivated by relativity theory. Yet many physicists continue to accept, usually on the reports of textbook writers and other commentators, that Bell’s own view was wrong, and that, in fact, the theorem only brings out a conflict with determinism or the hidden-variables program or realism or some other such principle that (...)
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5. David L. Thompson (1986). Intentionality and Causality in John Searle. Canadian Journal of Philosophy 16 (March):83-97.score: 24.0
Intentionality, as Brentano originally introduced the term in modern philosophy, was meant to provide a distinctive characteristic definitively separating the mental from the physical.(1) Mental states have an intrinsic relationship to an object, to that which they are "about." Physical entities just are what they are, they cannot, by their very essence, refer to anything, they have no "outreach", as one might put it. Mental states have, as it were, an incomplete essence, they cannot exist at all unless they are (...)
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6. Carl Hoefer (2005). Causality and Determinism: Tension, or Outright Conflict? Revista de Filosofía (Madrid) 29 (2):99-115.score: 24.0
In the philosophical tradition, the notions of determinism and causality are strongly linked: it is assumed that in a world of deterministic laws, causality may be said to reign supreme; and in any world where the causality is strong enough, determinism must hold. I will show that these alleged linkages are based on mistakes, and in fact get things almost completely wrong. In a deterministic world that is anything like ours, there is no room for genuine causation. (...)
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7. David Bohm (1957/1999). Causality and Chance in Modern Physics. University of Pennsylvania Press.score: 24.0
CHAPTER ONE Causality and Chance in Natural Law. INTRODUCTION IN nature nothing remains constant. Everything is in a perpetual state of transformation, ...
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8. Alexander Gebharter & Gerhard Schurz (2012). For a Better Understanding of Causality. Metascience 21 (3):643-648.score: 24.0
For a better understanding of causality Content Type Journal Article Category Essay Review Pages 1-6 DOI 10.1007/s11016-012-9648-3 Authors Alexander Gebharter, Department of Philosophy, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany Gerhard Schurz, Department of Philosophy, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.
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9. George Darby & Jon Williamson (2011). Imaging Technology and the Philosophy of Causality. Philosophy and Technology 24 (2):115-136.score: 24.0
Russo and Williamson (Int Stud Philos Sci 21(2):157–170, 2007) put forward the thesis that, at least in the health sciences, to establish the claim that C is a cause of E, one normally needs evidence of an underlying mechanism linking C and E as well as evidence that C makes a difference to E. This epistemological thesis poses a problem for most current analyses of causality which, in virtue of analysing causality in terms of just one of mechanisms (...)
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10. Francis Heylighen (2010). The Self-Organization of Time and Causality: Steps Towards Understanding the Ultimate Origin. [REVIEW] Foundations of Science 15 (4):345-356.score: 24.0
Possibly the most fundamental scientific problem is the origin of time and causality. The inherent difficulty is that all scientific theories of origins and evolution consider the existence of time and causality as given. We tackle this problem by starting from the concept of self-organization, which is seen as the spontaneous emergence of order out of primordial chaos. Self-organization can be explained by the selective retention of invariant or consistent variations, implying a breaking of the initial symmetry exhibited (...)
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11. Riccardo Luccio & Donata Milloni (2004). Perception of Causality: A Dynamical Analysis. In Alberto Peruzzi (ed.), Mind and Causality. Amsterdam: John Benjamins. 55--19.score: 24.0
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12. Günter Nimtz (2004). Superluminal Signal Velocity and Causality. Foundations of Physics 34 (12):1889-1903.score: 24.0
A superluminal signal velocity (i.e. faster than light) is said to violate causality. However, superluminal signal velocities have been measured in tunneling experiments recently. The classical dipole interaction approach by Sommerfeld and Brillouin results in a complex refractive index with a finite real part. For the tunneling process with its purely imaginary refractive index this model obtaines a zero-time traversing of tunneling barriers in agreement with wave meechanics. The information of a signal is proportional to the product of its (...)
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13. Rim Makni, Claude Francoeur & François Bellavance (2009). Causality Between Corporate Social Performance and Financial Performance: Evidence From Canadian Firms. [REVIEW] Journal of Business Ethics 89 (3):409 - 422.score: 24.0
This study assesses the causal relationship between corporate social performance (CSP) and financial performance (FP). We perform our empirical analyses on a sample of 179 publicly held Canadian firms and use the measures of CSP provided by Canadian Social Investment Database for the years 2004 and 2005. Using the “Granger causality” approach, we find no significant relationship between a composite measure of a firm’s CSP and FP, except for market returns. However, using individual measures of CSP, we find a (...)
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14. Alberto Peruzzi (ed.) (2004). Mind and Causality. John Benjamins.score: 24.0
By considering the developmental, phenomenological and biological aspects linking mind and causality, this volume offers a state-of-the art theoretical...
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15. Monte Ransome Johnson (2009). Spontaneity, Democritean Causality and Freedom. Elenchos 30 (1):5-52.score: 24.0
Critics have alleged that Democritus’ ethical prescriptions (“gnomai”) are incompatible with his physics, since his atomism seems committed to necessity or chance (or an awkward combination of both) as a universal cause of everything, leaving no room for personal responsibility. I argue that Democritus’ critics, both ancient and contemporary, have misunderstood a fundamental concept of his causality: a cause called “spontaneity”, which Democritus evidently considered a necessary (not chance) cause, compatible with human freedom, of both atomic motion and human (...)
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16. Phyllis McKay Illari, Federica Russo & Jon Williamson (eds.) (2011). Causality in the Sciences. Oxford University Press.score: 24.0
The book tackles these questions as well as others concerning the use of causality in the sciences.
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17. score: 24.0
Kant, in various parts of his treatment of causality, refers to determinism or the principle of sufficient reason as an inescapable principle. In fact, in the Second Analogy we find the elements to reconstruct a purely phenomenal determinism as a logical and tautological truth. I endeavour in this article to gather these elements into an organic theory of phenomenal causality and then show, in the third section, with a specific argument which I call the “paradox of phenomenal observation”, (...)
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18. Yahya Yasrebi (2007). A Critique of Causality in Islamic Philosophy. Topoi 26 (2):255-265.score: 24.0
After the problems of epistemology, the most fundamental problem of Islamic philosophy is that of causality. Causality has been studied from various perspectives. This paper endeavors first to analyze the issues of causality in Islamic philosophy and then to critique them. A sketch is provided of the history of the development of theories of causality in Islamic philosophy, with particular attention to how religious considerations came to determine the shape of the philosophical theories that were accepted. (...)
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19. Jon Williamson (2006). Dispositional Versus Epistemic Causality. Minds and Machines 16 (3):259-276.score: 24.0
I put forward several desiderata that a philosophical theory of causality should satisfy: it should account for the objectivity of causality, it should underpin formalisms for causal reasoning, it should admit a viable epistemology, it should be able to cope with the great variety of causal claims that are made, and it should be ontologically parsimonious. I argue that Nancy Cartwright’s dispositional account of causality goes part way towards meeting these criteria but is lacking in important respects. (...)
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20. Phyllis Illari (2011). Why Theories of Causality Need Production : An Information Transmission Account. [REVIEW] Philosophy and Technology 24 (2):95-114.score: 24.0
In this paper, I examine the comparatively neglected intuition of production regarding causality. I begin by examining the weaknesses of current production accounts of causality. I then distinguish between giving a good production account of causality and a good account of production. I argue that an account of production is needed to make sense of vital practices in causal inference. Finally, I offer an information transmission account of production based on John Collier’s work that solves the primary (...)
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21. Federica Russo & Jon Williamson (2011). Generic Versus Single-Case Causality: The Case of Autopsy. [REVIEW] European Journal for Philosophy of Science 1 (1):47-69.score: 24.0
This paper addresses questions about how the levels of causality (generic and single-case causality) are related. One question is epistemological: can relationships at one level be evidence for relationships at the other level? We present three kinds of answer to this question, categorised according to whether inference is top-down, bottom-up, or the levels are independent. A second question is metaphysical: can relationships at one level be reduced to relationships at the other level? We present three kinds of answer (...)
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22. Alberto Peruzzi (2004). Causality in the Texture of Mind. In Mind and Causality. Amsterdam: John Benjamins.score: 24.0
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23. Jon Williamson (2011). Generic Versus Single-Case Causality: The Case of Autopsy. [REVIEW] European Journal for Philosophy of Science 1 (1):47-69.score: 24.0
This paper addresses questions about how the levels of causality (generic and single-case causality) are related. One question is epistemological: can relationships at one level be evidence for relationships at the other level? We present three kinds of answer to this question, categorised according to whether inference is top-down, bottom-up, or the levels are independent. A second question is metaphysical: can relationships at one level be reduced to relationships at the other level? We present three kinds of answer (...)
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24. score: 24.0
Bayesian nets are widely used in artificial intelligence as a calculus for causal reasoning, enabling machines to make predictions, perform diagnoses, take decisions and even to discover causal relationships. But many philosophers have criticised and ultimately rejected the central assumption on which such work is based - the Causal Markov Condition. So should Bayesian nets be abandoned? What explains their success in artificial intelligence? -/- This book argues that the Causal Markov Condition holds as a default rule: it often holds (...)
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25. Rom Harré (2011). Do Explanation Formats in Elementary Chemistry Depend on Agent Causality? Foundations of Chemistry 13 (3):187-200.score: 24.0
By setting out the grammar of event causality, as developed by Hume and Mackie, in contrast to the grammar of agent causality in the natural sciences, a kind of hybrid hierarchical format for chemical explanations is sketched. From this starting point the history of agentive concepts in chemistry is displayed as a progression from Newton’s ‘forces’, through the nineteenth century concepts of ‘affinity’ and ‘valency’ to recent theories of molecular binding in terms of the migration of electrons and (...)
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26. Timothy L. Hubbard (2013). Phenomenal Causality II: Integration and Implication. [REVIEW] Axiomathes 23 (3):485-524.score: 24.0
The empirical literature on phenomenal causality (the notion that causality can be perceived) is reviewed. Different potential types of phenomenal causality and variables that influence phenomenal causality were considered in Part I (Hubbard 2012b) of this two-part series. In Part II, broader questions regarding properties of phenomenal causality and connections of phenomenal causality to other perceptual or cognitive phenomena (different types of phenomenal causality, effects of spatial and temporal variance, phenomenal causality in (...)
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27. score: 24.0
The finding of fractal scaling (FS) in behavioral sequences has raised a debate on whether FS is a pervasive property of the cognitive system or is the result of specific processes. Inferences about the origins of properties in time sequences are causal. That is, as opposed to correlational inferences reflecting instantaneous symmetrical relations, causal inferences concern asymmetric relations lagged in time. Here, I integrate Granger-causality with inferences about FS. Four simulations illustrate that causal analyses can isolate distinct FS sources, (...)
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28. Grzegorz Bugajak (2011). Causality and Determinism in Modern Physics. In Adam Świeżyński (ed.), Knowledge and Values, Wyd. UKSW, Warszawa. 73–94.score: 24.0
The paper revisits the old controversy over causality and determinism and argues, in the first place, that non˗deterministic theories of modern science are largely irrelevant to the philosophical issue of the causality principle. As it seems to be the ‘moral’ of the uncertainty principle, the reason why a deterministic theory cannot be applied to the description of certain physical systems is that it is impossible to capture such properties of the system, which are required by a desired theory. (...)
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29. Timothy L. Hubbard (2013). Phenomenal Causality I: Varieties and Variables. [REVIEW] Axiomathes 23 (1):1-42.score: 24.0
The empirical literature on phenomenal causality (i.e., the notion that causality can be perceived) is reviewed. In Part I of this two-part series, different potential types of phenomenal causality (launching, triggering, reaction, tool, entraining, traction, braking, enforced disintegration and bursting, coordinated movement, penetration, expulsion) are described. Stimulus variables (temporal gap, spatial gap, spatial overlap, direction, absolute velocity, velocity ratio, trajectory length, radius of action, size, motion type, modality, animacy) and observer variables (attention, eye movements and fixation, prior (...)
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30. Jon Williamson (2011). Imaging Technology and the Philosophy of Causality. Philosophy and Technology 24 (2):115-136.score: 24.0
Russo and Williamson (Int Stud Philos Sci 21(2):157–170, 2007) put forward the thesis that, at least in the health sciences, to establish the claim that C is a cause of E, one normally needs evidence of an underlying mechanism linking C and E as well as evidence that C makes a difference to E. This epistemological thesis poses a problem for most current analyses of causality which, in virtue of analysing causality in terms of just one of mechanisms (...)
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31. Adam Christian Scarfe (2012). Kant and Hegel's Responses to Hume's Skepticism Concerning Causality: An Evolutionary Epistemological Perspective. Cosmos and History: The Journal of Natural and Social Philosophy 8 (1):227-288.score: 24.0
According to Hume, determinations of necessary causal connection are without empirical warrant, but, as he maintains, the concept of causality qua necessary connection is indispensable to human beings, having survival value for them, a claim which points to the biological significance of this concept. In contrast to Hume, Kant argues that the causal principle qua necessary connection belongs to the a priori conceptual framework by which rational beings constitute their experience and render the world intelligible. In “Kant’s Doctrine of (...)
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32. Glenn Shafer (1995). The Situation of Causality. Foundations of Science 1 (4):543-563.score: 24.0
Causality in the abstract is a grand theme. We take it up when we want to penetrate to the bottom of things to understand general laws that govern the working at the world of the deepest and most detailed level.In this essay, I argue for a more situated understanding of causality. To counter our desire for ever greater generality, I suggest that causal relations, even those that hold only on average, require context. To counter our desire for ever (...)
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33. Miklos Redei & Stephen J. Summers (2002). Local Primitive Causality and the Common Cause Principle in Quantum Field Theory. Foundations of Physics 32 (3):335-355.score: 24.0
If $\mathcal{A}$ (V) is a net of local von Neumann algebras satisfying standard axioms of algebraic relativistic quantum field theory and V 1 and V 2 are spacelike separated spacetime regions, then the system ( $\mathcal{A}$ (V 1 ), $\mathcal{A}$ (V 2 ), φ) is said to satisfy the Weak Reichenbach's Common Cause Principle iff for every pair of projections A∈ $\mathcal{A}$ (V 1 ), B∈ $\mathcal{A}$ (V 2 ) correlated in the normal state φ there exists a projection C (...)
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34. Jukka Jernvall (2013). The Causality Horizon and the Developmental Bases of Morphological Evolution. Biological Theory 8 (3):286-292.score: 24.0
With the advent of evolutionary developmental research, or EvoDevo, there is hope of discovering the roles that the genetic bases of development play in morphological evolution. Studies in EvoDevo span several levels of organismal organization. Low-level studies identify the ultimate genetic changes responsible for morphological variation and diversity. High-level studies of development focus on how genetic differences affect the dynamics of gene networks and epigenetic interactions to modify morphology. Whereas an increasing number of studies link independent acquisition of homoplastic or (...)
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35. Justin Remhof (forthcoming). Naturalism, Causality, and Nietzsche's Conception of Science. Journal of Nietzsche Studies.score: 24.0
There is a puzzle over how to understand Nietzsche�s view of science. According to what I call the Negative View, Nietzsche thinks science should be reconceived or superseded by another discourse, such as art, because it is nihilistic. By contrast, what I call the Positive View holds that Nietzsche does not think science is nihilistic, so he denies that it should be reinterpreted or overcome. Interestingly, defenders of each position can appeal to Nietzsche�s understanding of naturalism to support their interpretation. (...)
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36. Gero Schwenk (2006). Interlevel Relations and Manipulative Causality. Journal for General Philosophy of Science 37 (1):99 - 110.score: 24.0
The topic of this article is the analysis of the relations between different levels of reality. The core argument is based on considerations of both an epistemology of action and manipulative causality as a criterion of object identity. The argumentation is extended towards the concepts of self-organization and self-regulation. Finally, several views on reduction and the problems of emergence and complexity are discussed.
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37. score: 24.0
Our somatosensory system deals with not only spatial but also temporal imprecision, resulting in characteristic spatiotemporal illusions. Repeated rapid stimulation at the wrist, then near the elbow, can create the illusion of touch at intervening locations along the arm (as if a rabbit is hopping along the arm). This is known as the “cutaneous rabbit effect” (CRE). Previous studies have suggested that the CRE involves not only an intrinsic somatotopic representation but also the representation of an extended body schema that (...)
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38. score: 24.0
Humans, even babies, perceive causality when one shape moves briefly and linearly after another. Motion timing is crucial in this and causal impressions disappear with short delays between motions. However, the role of temporal information is more complex: It is both a cue to causality and a factor that constrains processing. It affects ability to distinguish causality from non-causality, and social from mechanical causality. Here we study both issues with 3- to 7-year-olds and adults who (...)
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39. Dean Rickles (2009). Causality in Complex Interventions. Medicine, Health Care and Philosophy 12 (1):77-90.score: 24.0
In this paper I look at causality in the context of intervention research, and discuss some problems faced in the evaluation of causal hypotheses via interventions. I draw attention to a simple problem for evaluations that employ randomized controlled trials. The common alternative to randomized trials, the observational study, is shown to face problems of a similar nature. I then argue that these problems become especially acute in cases where the intervention is complex (i.e. that involves intervening in a (...)
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40. [deleted]Anjan Chatterjee Benjamin Straube (2010). Space and Time in Perceptual Causality. Frontiers in Human Neuroscience 4.score: 24.0
Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with (...)
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41. David Leech Anderson (2012). Causality-Dependent Consciousness and Consciousness-Dependent Causality. Journal of Consciousness Studies 19 (5-6):5-6.score: 24.0
This paper has two main goals. First, it asks whether causality is an adequate foundation for those theories of cognition and consciousness that are built upon it. The externalist revolution has reconceived all three dimensions of cognition -- the semantic, the epistemological, and the mental -- upon a foundation of 'causal connections of the appropriate type'. Yet, these new theories almost completely ignore the long-standing controversies surrounding the very nature of causality, and the very real threat that ' (...)' may be ill-equipped to do the work required of it. The second goal is to defend a kind of causality, largely ignored, that is grounded in the phenomenally conscious states of cognitive agents. While it is popular to try to reduce consciousness to causality, this is a kind of causality that ultimately reduces to (phenomenal) consciousness. (shrink)
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42. Alexander Gebharter & Gerhard Schurz (2014). Explanation, Causality, and Unification. Theoria. An International Journal for Theory, History and Foundations of Science 29 (1):5-7.score: 24.0
Editors' introduction to the monographic section Explanation, Causality, and Unification.
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43. Timothy O'Connor (2000). Causality, Mind, and Free Will. Noûs 34 (s14):105-117.score: 22.0
One familiar affirmative answer to this question holds that these facts suffice to entail that Descartes' picture of the human mind must be mistaken. On Descartes' view, our mind or soul (the only essential part of ourselves) has no spatial location. Yet it directly interacts with but one physical object, the brain of that body with which it is, 'as it were, intermingled,' so as to 'form one unit.' The radical disparity posited between a nonspatial mind, whose intentional and conscious (...)
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44. John Dilworth (2005). Perceptual Causality Problems Reflexively Resolved. Acta Analytica 20 (3):11-31.score: 22.0
Causal theories of perception typically have problems in explaining deviant causal chains. They also have difficulty with other unusual putative cases of perception involving prosthetic aids, defective perception, scientifically extended cases of perception, and so on. But I show how a more adequate reflexive causal theory, in which objects or properties X cause a perceiver to acquire X-related dispositions toward that very same item X, can provide a plausible and principled perceptual explanation of all of these kinds of cases. A (...)
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45. Zhu Xu (2010). Laws, Causality and the Intentional Explanation of Action. Frontiers of Philosophy in China 5 (2):280-293.score: 22.0
Whether or not an intentional explanation of action necessarily involves law-like statements is related to another question, namely, is it a causal explanation? The Popper-Hempel Thesis , which answers both questions affirmatively, inevitably faces a dilemma between realistic and universalistic requirements. However, in terms of W.C. Salmon’s concept of causal explanation, intentional explanation can be a causal one even if it does not rely on any laws. Based on this, we are able to refute three characteristic arguments for the claim (...)
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46. John Dilworth (2008). Semantic Naturalization Via Interactive Perceptual Causality. Minds and Machines 18 (4):527-546.score: 22.0
A novel semantic naturalization program is proposed. Its three main differences from informational semantics approaches are as follows. First, it makes use of a perceptually based, four-factor interactive causal relation in place of a simple nomic covariance relation. Second, it does not attempt to globally naturalize all semantic concepts, but instead it appeals to a broadly realist interpretation of natural science, in which the concept of propositional truth is off-limits to naturalization attempts. And third, it treats all semantic concepts as (...)
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47. Bert Schroer (2012). Causality and Dispersion Relations and the Role of the S-Matrix in the Ongoing Research. Foundations of Physics 42 (12):1481-1522.score: 22.0
The adaptation of the Kramers-Kronig dispersion relations to the causal localization structure of QFT led to an important project in particle physics, the only one with a successful closure. The same cannot be said about the subsequent attempts to formulate particle physics as a pure S-matrix project.The feasibility of a pure S-matrix approach are critically analyzed and their serious shortcomings are highlighted. Whereas the conceptual/mathematical demands of renormalized perturbation theory are modest and misunderstandings could easily be corrected, the correct understanding (...)
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48. X. U. Zhu (2010). Laws, Causality and the Intentional Explanation of Action. Frontiers of Philosophy in China 5 (2):280-293.score: 22.0
Whether or not an intentional explanation of action necessarily involves law-like statements is related to another question, namely, is it a causal explanation? The Popper–Hempel Thesis, which answers both questions affirmatively, inevitably faces a dilemma between realistic and universalistic requirements. However, in terms of W.C. Salmon’s concept of causal explanation, intentional explanation can be a causal one even if it does not rely on any laws. Based on this, we are able to refute three characteristic arguments for the claim “reason (...)
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49. John D. Bishop (1986). Is Agent-Causality a Conceptal Primitive? Synthese 67 (May):225-47.score: 21.0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5987070202827454, "perplexity": 5066.935925744426}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-49/segments/1416400380574.41/warc/CC-MAIN-20141119123300-00077-ip-10-235-23-156.ec2.internal.warc.gz"} |
https://cracku.in/ssc-chsl-21-jan-2017-afternoon-shift-question-paper-solved?page=9 | # SSC CHSL 21 Jan 2017 Afternoon Shift
Instructions
For the following questions answer them individually
Question 81
If Gafur's salary is 4/3 times of Haashim's and Satish's is 5/4 times of Haashim's, what is the ratio of Gafur's salary to Satish's?
Question 82
If cosecA/(cosecA - 1) + cosecA/(cosecA + 1) = x, then x is
Question 83
Which of the following is correct?
Question 84
Of the 3 numbers whose average is 77, the first is 3/4 times the sum of other 2. The first number is
Question 85
If the amount received at the end of 2nd and 3rd year at Compound Interest on a certain Principal is Rs 34992, and Rs 37791.36 respectively, what is the rate of interest?
Question 86
Slope of the side DA of the rectangle ABCD is -3/4. What is the slope of the side AB?
Question 87
If cot 30° - cos 45° = x, then x is
Question 88
The length of the diagonal of a rectangle is 10 cm and that of one side is 8 cm. What is the area of this rectangle?
Question 89
The two numbers are 55 and 99, HCF is 11, What is their LCM?
Question 90
A dishonest milkman buys milk at Rs 25 per litre and adds 1/5 of water to it and sells the mixture at Rs 29 per litre. His gain is
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http://nag.com/numeric/CL/nagdoc_cl23/html/F08/f08ffc.html | f08 Chapter Contents
f08 Chapter Introduction
NAG C Library Manual
# NAG Library Function Documentnag_dorgtr (f08ffc)
## 1 Purpose
nag_dorgtr (f08ffc) generates the real orthogonal matrix $Q$, which was determined by nag_dsytrd (f08fec) when reducing a symmetric matrix to tridiagonal form.
## 2 Specification
#include #include
void nag_dorgtr (Nag_OrderType order, Nag_UploType uplo, Integer n, double a[], Integer pda, const double tau[], NagError *fail)
## 3 Description
nag_dorgtr (f08ffc) is intended to be used after a call to nag_dsytrd (f08fec), which reduces a real symmetric matrix $A$ to symmetric tridiagonal form $T$ by an orthogonal similarity transformation: $A=QT{Q}^{\mathrm{T}}$. nag_dsytrd (f08fec) represents the orthogonal matrix $Q$ as a product of $n-1$ elementary reflectors.
This function may be used to generate $Q$ explicitly as a square matrix.
## 4 References
Golub G H and Van Loan C F (1996) Matrix Computations (3rd Edition) Johns Hopkins University Press, Baltimore
## 5 Arguments
1: orderNag_OrderTypeInput
On entry: the order argument specifies the two-dimensional storage scheme being used, i.e., row-major ordering or column-major ordering. C language defined storage is specified by ${\mathbf{order}}=\mathrm{Nag_RowMajor}$. See Section 3.2.1.3 in the Essential Introduction for a more detailed explanation of the use of this argument.
Constraint: ${\mathbf{order}}=\mathrm{Nag_RowMajor}$ or Nag_ColMajor.
2: uploNag_UploTypeInput
On entry: this must be the same argument uplo as supplied to nag_dsytrd (f08fec).
Constraint: ${\mathbf{uplo}}=\mathrm{Nag_Upper}$ or $\mathrm{Nag_Lower}$.
3: nIntegerInput
On entry: $n$, the order of the matrix $Q$.
Constraint: ${\mathbf{n}}\ge 0$.
4: a[$\mathit{dim}$]doubleInput/Output
Note: the dimension, dim, of the array a must be at least $\mathrm{max}\phantom{\rule{0.125em}{0ex}}\left(1,{\mathbf{pda}}×{\mathbf{n}}\right)$.
On entry: details of the vectors which define the elementary reflectors, as returned by nag_dsytrd (f08fec).
On exit: the $n$ by $n$ orthogonal matrix $Q$.
If ${\mathbf{order}}=\mathrm{Nag_ColMajor}$, the $\left(i,j\right)$th element of the matrix is stored in ${\mathbf{a}}\left[\left(j-1\right)×{\mathbf{pda}}+i-1\right]$.
If ${\mathbf{order}}=\mathrm{Nag_RowMajor}$, the $\left(i,j\right)$th element of the matrix is stored in ${\mathbf{a}}\left[\left(i-1\right)×{\mathbf{pda}}+j-1\right]$.
5: pdaIntegerInput
On entry: the stride separating row or column elements (depending on the value of order) of the matrix $A$ in the array a.
Constraint: ${\mathbf{pda}}\ge \mathrm{max}\phantom{\rule{0.125em}{0ex}}\left(1,{\mathbf{n}}\right)$.
6: tau[$\mathit{dim}$]const doubleInput
Note: the dimension, dim, of the array tau must be at least $\mathrm{max}\phantom{\rule{0.125em}{0ex}}\left(1,{\mathbf{n}}-1\right)$.
On entry: further details of the elementary reflectors, as returned by nag_dsytrd (f08fec).
7: failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).
## 6 Error Indicators and Warnings
NE_ALLOC_FAIL
Dynamic memory allocation failed.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_INT
On entry, ${\mathbf{n}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{n}}\ge 0$.
On entry, ${\mathbf{pda}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{pda}}>0$.
NE_INT_2
On entry, ${\mathbf{pda}}=〈\mathit{\text{value}}〉$ and ${\mathbf{n}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{pda}}\ge \mathrm{max}\phantom{\rule{0.125em}{0ex}}\left(1,{\mathbf{n}}\right)$.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
## 7 Accuracy
The computed matrix $Q$ differs from an exactly orthogonal matrix by a matrix $E$ such that
$E2 = Oε ,$
where $\epsilon$ is the machine precision.
The total number of floating point operations is approximately $\frac{4}{3}{n}^{3}$.
The complex analogue of this function is nag_zungtr (f08ftc).
## 9 Example
This example computes all the eigenvalues and eigenvectors of the matrix $A$, where
$A = 2.07 3.87 4.20 -1.15 3.87 -0.21 1.87 0.63 4.20 1.87 1.15 2.06 -1.15 0.63 2.06 -1.81 .$
Here $A$ is symmetric and must first be reduced to tridiagonal form by nag_dsytrd (f08fec). The program then calls nag_dorgtr (f08ffc) to form $Q$, and passes this matrix to nag_dsteqr (f08jec) which computes the eigenvalues and eigenvectors of $A$.
### 9.1 Program Text
Program Text (f08ffce.c)
### 9.2 Program Data
Program Data (f08ffce.d)
### 9.3 Program Results
Program Results (f08ffce.r) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 47, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9947894811630249, "perplexity": 2281.0908795873665}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042989790.89/warc/CC-MAIN-20150728002309-00030-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://www.jmlr.org/papers/v15/yamazaki14a.html | ## Asymptotic Accuracy of Distribution-Based Estimation of Latent Variables
Keisuke Yamazaki; 15(109):3721−3742, 2014.
### Abstract
Hierarchical statistical models are widely employed in information science and data engineering. The models consist of two types of variables: observable variables that represent the given data and latent variables for the unobservable labels. An asymptotic analysis of the models plays an important role in evaluating the learning process; the result of the analysis is applied not only to theoretical but also to practical situations, such as optimal model selection and active learning. There are many studies of generalization errors, which measure the prediction accuracy of the observable variables. However, the accuracy of estimating the latent variables has not yet been elucidated. For a quantitative evaluation of this, the present paper formulates distribution-based functions for the errors in the estimation of the latent variables. The asymptotic behavior is analyzed for both the maximum likelihood and the Bayes methods.
[abs][pdf][bib] | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.836000382900238, "perplexity": 516.2031352993276}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039560245.87/warc/CC-MAIN-20210422013104-20210422043104-00400.warc.gz"} |
https://www.physicsforums.com/threads/concentration-of-ammonia-in-a-solution.196081/ | # Concentration of ammonia in a solution
• Thread starter sveioen
• Start date
• #1
14
0
Hello all,
I had chemistry a long time ago, but now I am very rusty at it so I am hoping you can get me started with this problem I have;
A particular solution of ammonia (Kb = 1.8 x 10-5) has a pH of 8.3.
What is the concentration of ammonia in this solution?
Is it the concentration of NH3 I have to find? I know I can find [OH-] since I know the pH, but what does the final equation look like? Something like $$Kb=[OH-][NH4+]/[NH3]$$?
Thank you for any help!
## Answers and Replies
• #2
74
0
NH4 and OH- is going to have same amount of equilibrium concentration gained from the NH3. So If you know the pH, then how do you find the pOH, and what is the concentration of OH-? Multiply both sides by NH3 and divide bothsides by Kb. What happens?
• #3
14
0
Ok, so pOH = 14 - pH = 14 - 8,3 = 5,7. Concentration of OH- and NH4 is therefore $$1,995 \times 10^{-6}$$? And then $$[NH3] = \frac{[OH^-][NH4^+]}{K_b}$$?
• #4
74
0
So plug the values and see what you get, I hope this answer agree with the true answer, does it?? If not tell me.
• #5
14
0
I got $$2,21 \times 10^{-7}$$, which seems reasonable I guess. Maybe a bit low?!
• #6
74
0
You don't have the answer? It should be reasonable right? because its the equilibrum concentration right?
• #7
14
0
Nope dont have answer (yet) :(, but it seems kinda right.. Probably is equilibrum concentration..
• #8
1,939
50
I got $$2,21 \times 10^{-7}$$, which seems reasonable I guess. Maybe a bit low?!
I got $$2,21 \times 10^{-6}$$ instead.
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17K | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9008536338806152, "perplexity": 2930.9402145937984}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662522309.14/warc/CC-MAIN-20220518183254-20220518213254-00376.warc.gz"} |
http://www.ask.com/question/what-is-30ml-in-ounces | # What Is 30ml in Ounces?
30 ml is equivalent to 1.014 fluid ounces. Millilitre is a metric unit of measuring volume that is equivalent to a thousand of a litre while a fluid ounce is a unit of volume capacity equivalent to one twentieth of a pint. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.969977855682373, "perplexity": 2808.6840341321217}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394678694628/warc/CC-MAIN-20140313024454-00092-ip-10-183-142-35.ec2.internal.warc.gz"} |
http://mathhelpforum.com/calculus/169605-i-dont-get-simplification-print.html | # I don't get this simplification
Printable View
• January 28th 2011, 02:01 PM
konvos
I don't get this simplification
I can't see how they did this operation.
http://img824.imageshack.us/img824/1111/simpr.png
thx for the help.
• January 28th 2011, 02:09 PM
pickslides
Looks like simple trig identities to me i.e. $2\sin x \cos x = \sin 2x$
• January 28th 2011, 02:09 PM
Archie Meade
Quote:
Originally Posted by konvos
I can't see how they did this operation.
http://img824.imageshack.us/img824/1111/simpr.png
thx for the help.
$sin(2x)=2sinxcosx$
$-sin^2x+cos^2x=-sin^2x-cos^2x+2cos^2x$
and
$cos^2x+sin^2x=1\Rightarrow\ -\left(sin^2x+cos^2x\right)=-1$
• January 28th 2011, 02:11 PM
Houdini
Ok..1.sin2(x) + cos2(x) = 1=>sin2(x)=1+cos2(x)....but you have - in front of sin so you can see why -1+cos2(x)
2.sin(2x) = 2 sin x cos x
from 1 and 2 =>-sin2(x) + cos2(x)+2 sin x cos x=-1+cos2(x)+sin(2x)
• January 28th 2011, 02:23 PM
konvos
thx for the help everybody
Quote:
Originally Posted by Archie Meade
$sin(2x)=2sinxcosx$
$-sin^2x+cos^2x=-sin^2x-cos^2x+2cos^2x$
and
$cos^2x+sin^2x=1\Rightarrow\ -\left(sin^2x+cos^2x\right)=-1$
I'd no idea of this identity http://www.mathhelpforum.com/math-he...2177745298.png
I suppose I should review trig...
• January 28th 2011, 02:48 PM
Defunkt
$-sin^2x + cos^2x = -sin^2x + (cos^2x - cos^2x) + cos^2x =$
$= -sin^2x -cos^2x + cos^2x + cos^2x$
$= -(sin^2x + cos^2x) + 2cos^2x$
$= -1 + 2cos^2x$
• January 28th 2011, 04:44 PM
Archie Meade
Quote:
Originally Posted by konvos
thx for the help everybody
I'd no idea of this identity http://www.mathhelpforum.com/math-he...2177745298.png
I suppose I should review trig...
No, that's not an identity.
Just algebraic manipulation.
You could of course use identities to weave your way to the final line.
• January 28th 2011, 05:59 PM
mr fantastic
Quote:
Originally Posted by Defunkt
$-sin^2x + cos^2x = -sin^2x + (cos^2x - cos^2x) + cos^2x =$
$= -sin^2x -cos^2x + cos^2x + cos^2x$
$= -(sin^2x + cos^2x) + 2cos^2x$
$= -1 + 2cos^2x$
It's also probably worth noting that $\cos^2(x) - \sin^2(x) = \cos(2x)$ is a standard double angle formula (because I just know that the next question asked by the OP will be how to find y ....) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 16, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8087837100028992, "perplexity": 3909.7131298284908}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440644065375.30/warc/CC-MAIN-20150827025425-00164-ip-10-171-96-226.ec2.internal.warc.gz"} |
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# I got 450 my diagnostic test... HELP
Author Message
Intern
Joined: 25 Jan 2013
Posts: 35
Location: Spain
Concentration: Finance, Other
Schools: Wharton '17 (S)
GMAT 1: 740 Q49 V42
Followers: 1
Kudos [?]: 64 [0], given: 12
I got 450 my diagnostic test... HELP [#permalink]
### Show Tags
04 Feb 2013, 05:26
I recently did my diagnostic test and got 450 (q 18 -yes, I know is sad- and v 32). I am not a native speaker so I was surprised with my relatively good verbal performance. On the other hand, my quant performance is really poor (only got 15 questions right). I am a lawyer and never studied math at college. I know that I have to strenght my quant abilities and think I can do it. Can anyone help me with some tips? Is it possible for me to achieve a 700?
Director
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 547
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Followers: 3
Kudos [?]: 56 [1] , given: 562
Re: I got 450 my diagnostic test... HELP [#permalink]
### Show Tags
05 Feb 2013, 02:34
1
KUDOS
spla626 wrote:
I recently did my diagnostic test and got 450 (q 18 -yes, I know is sad- and v 32). I am not a native speaker so I was surprised with my relatively good verbal performance. On the other hand, my quant performance is really poor (only got 15 questions right). I am a lawyer and never studied math at college. I know that I have to strenght my quant abilities and think I can do it. Can anyone help me with some tips? Is it possible for me to achieve a 700?
congrats on a great verbal score.
Well, you can definitely improve on your quant score. Its just a matter of perserverance.
Manhattan GMAT Quant Guides are the best in my opinion. Buy and Start studying them and do the corresponding questions from OG mentioned at the end of the chapter.
Try to analyse every question that you got incorrect and also those questions on which you guessed.
In short you must know why the correct answer is correct.
Press kudos if this helps.
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.
Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595
My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Intern
Joined: 25 Jan 2013
Posts: 35
Location: Spain
Concentration: Finance, Other
Schools: Wharton '17 (S)
GMAT 1: 740 Q49 V42
Followers: 1
Kudos [?]: 64 [0], given: 12
Re: I got 450 my diagnostic test... HELP [#permalink]
### Show Tags
05 Feb 2013, 03:21
Sachin9 wrote:
spla626 wrote:
I recently did my diagnostic test and got 450 (q 18 -yes, I know is sad- and v 32). I am not a native speaker so I was surprised with my relatively good verbal performance. On the other hand, my quant performance is really poor (only got 15 questions right). I am a lawyer and never studied math at college. I know that I have to strenght my quant abilities and think I can do it. Can anyone help me with some tips? Is it possible for me to achieve a 700?
congrats on a great verbal score.
Well, you can definitely improve on your quant score. Its just a matter of perserverance.
Manhattan GMAT Quant Guides are the best in my opinion. Buy and Start studying them and do the corresponding questions from OG mentioned at the end of the chapter.
Try to analyse every question that you got incorrect and also those questions on which you guessed.
In short you must know why the correct answer is correct.
Press kudos if this helps.
Thank you very much for your reply! I will follow your advice! I need to practice, practice and practice, I guess. Actually, I normally understand what I do wrong and why a particular answer is correct. However, when I have to do it by myself in less than two minutes the things are not so easy.
Director
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 547
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Followers: 3
Kudos [?]: 56 [1] , given: 562
Re: I got 450 my diagnostic test... HELP [#permalink]
### Show Tags
05 Feb 2013, 03:45
1
KUDOS
spla626 wrote:
Thank you very much for your reply! I will follow your advice! I need to practice, practice and practice, I guess. Actually, I normally understand what I do wrong and why a particular answer is correct. However, when I have to do it by myself in less than two minutes the things are not so easy.
No probs
Consider studying 'foundation of gmat quant' by manhattan gmat if you think you need soem more help.
Make flash cards and revise them every week. Quiz yourself every week. This helped me too.
Kudos if this helped
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.
Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595
My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Manager
Joined: 15 Nov 2009
Posts: 123
Concentration: Finance
GMAT 1: 680 Q48 V35
GMAT 2: 700 Q48 V37
Followers: 1
Kudos [?]: 48 [1] , given: 15
Re: I got 450 my diagnostic test... HELP [#permalink]
### Show Tags
05 Feb 2013, 04:23
1
KUDOS
A verbal 32 is not bad, but there is still room for improvement
For the moment, you have to focus on your quant score.
As Sachin9 said, read prep books with foundations (Manhattan's collection is excellent).
Do not underestimate seemingly simple math questions. Read every paragraph in detail and do the exercises to make sure you learned the concepts.
Do not overuse practice tests... they are limited resources.
Best
Intern
Joined: 25 Jan 2013
Posts: 35
Location: Spain
Concentration: Finance, Other
Schools: Wharton '17 (S)
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Re: I got 450 my diagnostic test... HELP [#permalink]
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05 Feb 2013, 05:02
rainfall wrote:
A verbal 32 is not bad, but there is still room for improvement
For the moment, you have to focus on your quant score.
As Sachin9 said, read prep books with foundations (Manhattan's collection is excellent).
Do not underestimate seemingly simple math questions. Read every paragraph in detail and do the exercises to make sure you learned the concepts.
Do not overuse practice tests... they are limited resources.
Best
Thank you very much! I really appreciate your attention. I like this community, where everybody helps each other. Another problem I have in quant is my slowness in mental calculus. The thinq is, how is suposed that a person with no math background at all will "compete" with a lot of people very well prepared in quant issues? That is one of my main concerns.
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Re: I got 450 my diagnostic test... HELP [#permalink]
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05 Feb 2013, 07:25
1
KUDOS
spla626 wrote:
rainfall wrote:
A verbal 32 is not bad, but there is still room for improvement
For the moment, you have to focus on your quant score.
As Sachin9 said, read prep books with foundations (Manhattan's collection is excellent).
Do not underestimate seemingly simple math questions. Read every paragraph in detail and do the exercises to make sure you learned the concepts.
Do not overuse practice tests... they are limited resources.
Best
Thank you very much! I really appreciate your attention. I like this community, where everybody helps each other. Another problem I have in quant is my slowness in mental calculus. The thinq is, how is suposed that a person with no math background at all will "compete" with a lot of people very well prepared in quant issues? That is one of my main concerns.
Mate,
You must never calculate anything mentally. Mental calculation is many many times error prone. Ron Purewal, world's best instructor, told me this.
As rainfall said, you gotto get used to the formulas and concepts and that might take sometime but with perseverance, you can tackle anything.
Go through the foundation book of quant by mgmat and then take their quant foundation test on thier website. This will give you a good idea about where you stand.
Any help u need, post your questions here! people would respond
Press Kudos if this helps
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Re: I got 450 my diagnostic test... HELP [#permalink]
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05 Feb 2013, 19:45
spla626 wrote:
I recently did my diagnostic test and got 450 (q 18 -yes, I know is sad- and v 32). I am not a native speaker so I was surprised with my relatively good verbal performance. On the other hand, my quant performance is really poor (only got 15 questions right). I am a lawyer and never studied math at college. I know that I have to strenght my quant abilities and think I can do it. Can anyone help me with some tips? Is it possible for me to achieve a 700?
Hi!
The most important thing is not to panic. I have a BS in Mathematics, but I have a hard time on some GMAT questions, because they test a few high-school level gimmicks, rather than the pure mathematics I studied in college.
My recommendation is to do the 13th Edition Official Review diagnostic (or any diagnostic for that matter) and see what types of questions you're prone to get wrong. Then, go out and buy the Manhattan GMAT books that pertain to those sections (I bought them all, because they show you a ton of useful tricks). Trust me - after doing five to ten questions of any given type, you're substantially more likely to get it right. Also - be sure to continue working on the Verbal; you're on the right track with your 32, but if you want to get a 700, you'll need to score somewhere in the low 40's.
Like I said - don't panic, and don't get discouraged. It takes a lot of determination, but I'm sure that a lawyer such as yourself has all the fundamental tools, verbal and quantitative, to do very well on the GMAT. You just need the practice.
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Re: I got 450 my diagnostic test... HELP [#permalink]
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05 Feb 2013, 20:28
1
KUDOS
Expert's post
spla626 wrote:
Thank you very much! I really appreciate your attention. I like this community, where everybody helps each other. Another problem I have in quant is my slowness in mental calculus. The thinq is, how is suposed that a person with no math background at all will "compete" with a lot of people very well prepared in quant issues? That is one of my main concerns.
You don't need very much to go from 'not prepared' to 'prepared' as far as GMAT goes since the concepts tested are very basic. GMAT assumes only high school Math proficiency. The problem is that high school was far back so a thorough brush up is a must. You need to go through a complete set of prep material along with sectional tests to get the concepts right. This step alone will bring your Math score in the 30s range. Thereafter, it will be a game of identifying weak areas and working again on them.
As for mental calculations, before you begin doing them, you need to 'know' a few things like multiplication tables. Remember, most GMAT questions can be solved in under a minute without putting your pen to the paper. You don't need to try that right now since you are just starting out. In fact, even if you do write down a few things, you still have enough time. But you need to be able to cut down steps by working them out in your mind else time will be short.
Check out my post on how to handle calculations in GMAT:
http://www.veritasprep.com/blog/2012/04 ... culations/
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Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Intern Joined: 25 Jan 2013 Posts: 35 Location: Spain Concentration: Finance, Other Schools: Wharton '17 (S) GMAT 1: 740 Q49 V42 Followers: 1 Kudos [?]: 64 [0], given: 12 Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink] ### Show Tags 15 May 2013, 03:26 I started this topic 3 months and 10 days ago. I needed help because I had taken my diagnostic test and scored just a poor 450 (18 q and 32 v). After following all the helpful advices -really really helpful-, I have recently taken the Gmat Prep I. The score was a happy surprise because it was a 630 (38 q 38 v). A jump of 180 point! Now I have my real test scheaduled in two months -20th July-, and I would like to have more advice on how to use this two months left in order to make the last big jump ang get into the 700 swimming pool. Particularly, I know what I have to do on quant -finish geometry, equations and ineqs and word translations guides from mgmat. the greates souce-. I think that after that I can reach low 40s in quant and then practice until be able to break the 45 barrier. However, I assume that I won't be able to score 49 in two months left -I think my real limit is 47-, so I am interested in bringing my verbal score from 38 to 42, if possible. Any advice on that? Any more general advice? I am making any wrong assumptions here? Will I be able to reach 700? Thanks in advance VP Status: Far, far away! Joined: 02 Sep 2012 Posts: 1123 Location: Italy Concentration: Finance, Entrepreneurship GPA: 3.8 Followers: 177 Kudos [?]: 1869 [1] , given: 219 Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink] ### Show Tags 15 May 2013, 03:46 1 This post received KUDOS spla626 wrote: I started this topic 3 months and 10 days ago. I needed help because I had taken my diagnostic test and scored just a poor 450 (18 q and 32 v). After following all the helpful advices -really really helpful-, I have recently taken the Gmat Prep I. The score was a happy surprise because it was a 630 (38 q 38 v). A jump of 180 point! Now I have my real test scheaduled in two months -20th July-, and I would like to have more advice on how to use this two months left in order to make the last big jump ang get into the 700 swimming pool. Particularly, I know what I have to do on quant -finish geometry, equations and ineqs and word translations guides from mgmat. the greates souce-. I think that after that I can reach low 40s in quant and then practice until be able to break the 45 barrier. However, I assume that I won't be able to score 49 in two months left -I think my real limit is 47-, so I am interested in bringing my verbal score from 38 to 42, if possible. Any advice on that? Any more general advice? I am making any wrong assumptions here? Will I be able to reach 700? Thanks in advance First of all, congrats on your 180 points jump! To improve your Verbal score you should focus in order: SC, CR and RC. With practice you start to recognize some patterns in SC (parallelism, modifiers,...) and this will speed up your time in those questions. Every second you save here can be useful in the other questions. My advise is CR second and RC third because the skills you acquire with CR can be used also in RC. So these sections can be seen as one under many points of view (inference, method of reasoning,...) This is what works for me, hope you find it useful too If you are looking for books on SC, I can recommend you the SC from the Veritas's Gmat Series or the SC form MGMAT. One last thing: if you wanna know "what does it take to reach 700"take a look here. _________________ It is beyond a doubt that all our knowledge that begins with experience. Kant , Critique of Pure Reason Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b] Intern Joined: 25 Jan 2013 Posts: 35 Location: Spain Concentration: Finance, Other Schools: Wharton '17 (S) GMAT 1: 740 Q49 V42 Followers: 1 Kudos [?]: 64 [0], given: 12 Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink] ### Show Tags 15 May 2013, 04:31 Zarrolou wrote: spla626 wrote: I started this topic 3 months and 10 days ago. I needed help because I had taken my diagnostic test and scored just a poor 450 (18 q and 32 v). After following all the helpful advices -really really helpful-, I have recently taken the Gmat Prep I. The score was a happy surprise because it was a 630 (38 q 38 v). A jump of 180 point! Now I have my real test scheaduled in two months -20th July-, and I would like to have more advice on how to use this two months left in order to make the last big jump ang get into the 700 swimming pool. Particularly, I know what I have to do on quant -finish geometry, equations and ineqs and word translations guides from mgmat. the greates souce-. I think that after that I can reach low 40s in quant and then practice until be able to break the 45 barrier. However, I assume that I won't be able to score 49 in two months left -I think my real limit is 47-, so I am interested in bringing my verbal score from 38 to 42, if possible. Any advice on that? Any more general advice? I am making any wrong assumptions here? Will I be able to reach 700? Thanks in advance First of all, congrats on your 180 points jump! To improve your Verbal score you should focus in order: SC, CR and RC. With practice you start to recognize some patterns in SC (parallelism, modifiers,...) and this will speed up your time in those questions. Every second you save here can be useful in the other questions. My advise is CR second and RC third because the skills you acquire with CR can be used also in RC. So these sections can be seen as one under many points of view (inference, method of reasoning,...) This is what works for me, hope you find it useful too If you are looking for books on SC, I can recommend you the SC from the Veritas's Gmat Series or the SC form MGMAT. One last thing: if you wanna know "what does it take to reach 700"take a look here. Thanks very much for your advise. I have tried SMARTGMAT and have liked too much. I think it provides a great insight on how to plan my time left before the test. After using it, my conclusion is that I need to balance my study. Because I think I won't be able to reach some percentiles in verbal nor in quant. Particularly, given the time left -two months-, I think I have a ceiling of 42 in verbal and 47 -at max- in quant, which gives a 730 -that would make me be sooo happy-. The only but of SMARTGMAT is that it seems to assume that there are no limits of improving a particular area. For instance, as I said, I think that it is not possible for me to reach above 47 in quant -given the time left and my natural capabilities-, so much less to score a 50 or 51. In spite of this, indeed, it is a great software. Thanks again! Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 6972 Location: Pune, India Followers: 2034 Kudos [?]: 12790 [1] , given: 221 Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink] ### Show Tags 15 May 2013, 09:50 1 This post received KUDOS Expert's post spla626 wrote: I started this topic 3 months and 10 days ago. I needed help because I had taken my diagnostic test and scored just a poor 450 (18 q and 32 v). After following all the helpful advices -really really helpful-, I have recently taken the Gmat Prep I. The score was a happy surprise because it was a 630 (38 q 38 v). A jump of 180 point! Now I have my real test scheaduled in two months -20th July-, and I would like to have more advice on how to use this two months left in order to make the last big jump ang get into the 700 swimming pool. Particularly, I know what I have to do on quant -finish geometry, equations and ineqs and word translations guides from mgmat. the greates souce-. I think that after that I can reach low 40s in quant and then practice until be able to break the 45 barrier. However, I assume that I won't be able to score 49 in two months left -I think my real limit is 47-, so I am interested in bringing my verbal score from 38 to 42, if possible. Any advice on that? Any more general advice? I am making any wrong assumptions here? Will I be able to reach 700? Thanks in advance That's some solid improvement but be prepared for more grilling over the next 2 months if you are aiming for 700. In fact, this 70 point jump will be more difficult than the 180 point jump. You must be comfortable with most basic concepts now. The problem will be advanced application. If you already know areas that you must first work on, great! It means there is still scope of good improvement with little effort. Once you finish the complete prep material, then take a test and figure out what score you are at. After that, the improvement is usually slower so keep your patience. Verbal has few basics but wide application so drill down those basics first - The various questions types in CR/RC - how to tackle each, the various errors in SC - the different forms it can take etc. Then practice as much as you can. A 47-42 split is reasonable. Whether you will be able to reach 700 depends on your drive. It's certainly possible. _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199
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Re: I got 450 my diagnostic test... HELP [#permalink]
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16 May 2013, 21:52
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Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink]
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23 Jul 2013, 02:18
Thank you all people on the forum for your kind replies and knowledge.
I have a question. Yesterday i took a gmat prep. It's been a while since i took the last test. I got 760. But stop. These are not exactly good news: i had done before arround 70 % of the questions. I did not remember all the questions but they were familiar to me. However, when i knew the exact answer i did it wrong (this happened with 3 questions in quant). Anyway, that 760 is totally inflated.
But, my question is, where i am standing right now. Hundred points below? 50? 120? I do not know, and would like to have the insight of an expert or any people on the forums.
Second, i have done thousands of questions of all sources. So i cannot trust any test i find in the market (i think). How can i asses or test my level now?
I have my test on august 1. Any comments will be appreciated.
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Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink]
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23 Jul 2013, 23:20
spla626 wrote:
Thank you all people on the forum for your kind replies and knowledge.
I have a question. Yesterday i took a gmat prep. It's been a while since i took the last test. I got 760. But stop. These are not exactly good news: i had done before arround 70 % of the questions. I did not remember all the questions but they were familiar to me. However, when i knew the exact answer i did it wrong (this happened with 3 questions in quant). Anyway, that 760 is totally inflated.
But, my question is, where i am standing right now. Hundred points below? 50? 120? I do not know, and would like to have the insight of an expert or any people on the forums.
Second, i have done thousands of questions of all sources. So i cannot trust any test i find in the market (i think). How can i asses or test my level now?
I have my test on august 1. Any comments will be appreciated.
Try out our free question bank. There are tons of new questions in it. If you do well in them, you are good to go.
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Re: I got 450 my diagnostic test... HELP... JUMPED TO 630... [#permalink] 23 Jul 2013, 23:20
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# I got 450 my diagnostic test... HELP
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Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5313758254051208, "perplexity": 3131.5738764995526}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988721387.11/warc/CC-MAIN-20161020183841-00414-ip-10-171-6-4.ec2.internal.warc.gz"} |
http://suexcxine.win/page/2/ | # 对erlang并行及性能的精彩评论
Almost any language can be parallelized. In some languages it's simple, in others it's a pain in the butt, but it can be done. If you want to run a C++ program across 8000 CPU's in a grid, go ahead! You can do that. It's been done before.
Erlang doesn't do anything that's impossible in other languages. If a single CPU running an Erlang program is less efficient than the same CPU running a C++ program, then two hundred CPU's running Erlang will also be slower than two hundred CPU's running C++.
What Erlang does do is making this kind of parallelism easy to work with. It saves developer time and reduces the chance of bugs.
So I'm going to say no, there is no tipping point at which Erlang's parallelism allows it to outperform another language's numerical number-crunching strength.
Where Erlang scores is in making it easier to scale out and do so correctly. But it can still be done in other languages which are better at number-crunching, if you're willing to spend the extra development time.
And of course, let's not forget the good old point that languages don't have a speed. A sufficiently good Erlang compiler would yield perfectly optimal code. A sufficiently bad C compiler would yield code that runs slower than anything else.
## 参考链接
http://stackoverflow.com/questions/1308527/when-does-erlangs-parallelism-overcome-its-weaknesses-in-numeric-computing
# CSAPP
• 避免由于计算机表示数字的方式引入奇怪的数字错误
• 利用现在处理器和内存的设计优化C代码
• 理解编译器如何实现过程调用,避免缓存溢出带来的安全漏洞
• 写自己的shell,自己的动态存储分配等
# Chapter 1 A Tour of Computer Systems
## 1.3 It Pays to Understand How Compilation Systems Work
Is a switch statement always more efficient than a sequence of if-else statements?
How much overhead is incurred by a function call?
Is a while loop more efficient than a for loop?
Are pointer references more efficient than array indexes?
Why does our loop run so much faster if .we sum into a local variable instead of an argument that is passed by reference?
How can a function run faster when we simply rearrange the parentheses in an arithmetic expression?
what does it mean when the linker reports that it cannot resolve a reference?
What is the difference between a static variable and a.global variable?
What happens if you define two global variables in different C files with the same name?
What is the difference between a static library and a dynamic library?
Why does it matter what order we list libraries on the command line?
And scariest of all, why do some linker-related errors not appear until runtime?
## 1.4 Processors. Read and Interpret Instructions Stored-in Memory
PC: 程序计数器, 是CPU中的一个寄存器, 保存一个内存地址, 这个地址指向下一个要执行的指令
• Store 从寄存器写到内存
• Operate 从两个寄存器取出值, 进行算术运算后覆盖到一个寄存器
• Jump 从指令中取出一个word并覆盖PC的值, 实现跳转
## 1.7 The Operating System Manages the Hardware
1, 保护硬件, 避免应用程序误用导致硬件损坏
2, 提供简单通用的接口供应用程序使用硬件
Kernel virtual memory, 应用程序不允许读写这个区域, 需要调用内核
User stack(created at run time)
Memory-mapped region for shared libraries
Run-time heap(created by malloc)
Unix中一切都是文件统一了不同的IO设备(键盘,鼠标,磁盘,显示器,网络,打印机等)
Amdahl定律
# CLRS
NP完全问题, 这些问题没有最优解, 只能尝试找较好的解
# iostat
## iostat
sudo apt-get install sysstat
yum install sysstat
iostat
Linux 3.19.0-66-generic (chenduo) 2016年08月13日 _x86_64_ (8 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
28.30 0.06 11.32 1.43 0.00 58.88
sda 3.44 21.71 99.34 6225040 28490308
user: 用户级时间比例
nice: nice优先级时间比例
system: 系统级时间比例
iowait: 等待io的时间比例,相当于top里的wa
steal: 虚拟环境下等待物理CPU周期的时间比例
idle: 空闲时间比例, 相当于top里的id
tps: transfer per second, 一次transfer就是一次io
### steal
Xen和KVM支持这个值,貌似vmware和virtualbox都不支持
# mysql 事务
InnoDB使用不同的锁策略来支持不同的事务隔离级别.
COMMIT意味着变更确定持久化, ROLLBACK意味着放弃尚未持久化的变更, 两个操作都会释放锁.
transaction里select和update两句话之间有可能执行其他transaction的update语句么? || 有可能
# data source name
[username[:password]@][protocol[(address)]]/dbname[?param1=value1&...¶mN=valueN]
username:password@protocol(address)/dbname?param=value | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.15060020983219147, "perplexity": 5151.721580056039}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247494485.54/warc/CC-MAIN-20190220065052-20190220091052-00289.warc.gz"} |
https://www.physicsforums.com/threads/photoelectrons-ejecting-from-cs-metal.729202/ | # Photoelectrons ejecting from Cs metal
1. Dec 19, 2013
### utkarshakash
1. The problem statement, all variables and given/known data
A small piece of cesium metal (W=1.9eV) is kept at a distance of 20cm from a large metal plate having a charge density of 1.0*10^-9 C m^-2 on the surface facing the cesium piece. A monochromatic light of wavelength 400nm is incident on the cesium piece. Find the minimum and the maximum kinetic energy of the photoelectrons reaching the large metal plate.
2. Relevant equations
3. The attempt at a solution
I can find the electric field due to metal plate and thus the corresponding potential difference. I can also find the stopping potential. But what about kinetic energies?
2. Dec 19, 2013
### Zondrina
I believe to find $E_{k_{max}}$ you should use:
$E_k = \frac{hc}{\lambda} - W$ - Don't forget to convert your work function into Joules and nm to meters.
If you knew the cutoff voltage, there would be another way to find the max kinetic energy as well by using the charge density.
Also, to find $E_{k_{min}}$, you should think about what causes the minimum kinetic energy. Think about the threshold frequency and how it relates to the minimum kinetic energy. The light must meet this minimum frequency in order to give enough energy to the photoelectrons, so that they can be ejected from the cesium metal to the large metal plate.
Last edited: Dec 19, 2013
3. Dec 19, 2013
### rude man
Since there is only one radiating frequency there will be one value of k.e. corresponding to the difference between hf and the given work function W. That would have to be the max. k.e. also.
To determine the min. k.e. it seems one would have to know the distribution of the work function for Cesium among its atoms, which I could not find. This may instead have to do with the energy levels of the electrons in each atom. The min. W would be associated with the outermost orbital electrons, which would = 1.9 eV, and the max. W with the innermost orbital electrons, for which W = outermost W + difference in energy betw. outermost & innermost electrons. Need expert physics help here ...
4. Dec 19, 2013
### utkarshakash
I did my calculation and got KE(max) = 1.19eV which is not correct.
5. Dec 19, 2013
### rude man
You did not include the effect of the electric field. You just computed the photon energy and subtracted the work function.
BTW are you sure the charge on the plate is positive? It's usually negative in experiments.
The serious question of minimum k.e. remains ...
6. Dec 20, 2013
### utkarshakash
But the question mentions that electric field is to be neglected (sorry for not giving that info earlier).
7. Dec 20, 2013
### ehild
hc/λ-W=KE(max), the maximum kinetic energy. That is the KE of the electrons which escaped the metal from the top of the potential well. Other electrons can have less KE than that. The minimum KE of the electrons leaving the metal is zero. They are accelerated by the electric field on the surface charge of the opposite metal plate . That surface charge density is 1.0*10^-9 C m^-2 positive (there would be a minus sign in front otherwise). What is the electric field between the metal plate and the Caesium piece?
ehild
8. Dec 20, 2013
### rude man
Why should the electric field be neglected if it was given in great detail?
9. Dec 20, 2013
### rude man
You have not explained how electrons can have zero emitted k.e. Why zero exactly?
A photon at 400 nm imparts 3.1 eV to an electron, which exceeds the work function by 1.2 eV. How can an electron be kicked to the surface with zero k.e. or indeed with any k.e. < 1.2 eV? Must have something to do with the quantized electron energy levels: S, P etc. And if it does, the lowest released electron's k.e. is not likely to be zero since the orbital electron levels are quantized. Would be quite a coincidence.
10. Dec 20, 2013
### ehild
The energy levels in a crystal are arranged in bands. The energy levels in the band, although quantized, are very close to each other: the atomic levels split when the atoms interact. In case of two interacting atoms, they split into two, in case of N atoms in a crystal, they split into N sub-levels. The outermost electrons occupy levels in the valence band, those of the metals occupy levels in the conduction band. There are electrons with energy near the bottom of the band and there are others near the Fermi level.
Have you ever asked yourself why the maximum kinetic energy appears in the equation hf=W+KE(max)?
KE(max) is the upper bound for the KE of the electrons kicked out of the metal, so there must be ones with lower KE. What can be the lower bound of the KE? Anyway, it can not be negative.
ehild
Last edited: Dec 20, 2013
11. Dec 20, 2013
### rude man
Of course it cannot be negative, but my question was, what is it?
But OK, what I have found is that
work function phi = E0 - EF
where E0 is the energy required to kick an electron out of the lowest free electron state, and EF is the Fermi level. Since EF for Cesium = 1.6 eV and phi = 1.9 eV, this indicates that E0 ~ 3.5 eV for Cs. There is a continuum of electron energies with values from - 3.5 eV to -1.9 eV so there is effectively a continuum of work functions also, from 1.9 eV to 3.5 eV. The work function given (1.9 eV) is the energy required to liberate an electron in the highest free electron state; all lower-state electrons require more than 1.9 eV. The lowest-state electrons require a light frequency f corresponding to hf = 3.5 eV. This frequency is above our light emitter frequency of c/λ, λ = 400 nm.
So, bottom line, the lowest emitted electron k.e. is indeed zero since the 400 nm radiation can liberate electrons only to the - 3.1 eV level.
So now the OP can compute the range of kinetic energies at the charged plate.
Last edited: Dec 20, 2013
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https://optimization.mccormick.northwestern.edu/index.php?title=Classical_robust_optimization&oldid=1748&printable=yes | # Classical robust optimization
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Author Names: Andre Ramirez-Cedeno
Steward: Fengqi You, Dajun Yue
# Classical Robust Optimization
## Indroduction and History
Robust optimization is a subset of optimization theory that deals with a certain measure of robustness vs uncertainty. This balance of robustness and uncertainty is represented as variability in the parameters of the problem at hand and or its solution. Robust optimization dates back to the beginning of modern decision theory in the 1950’s. It became a discipline of its own in the 1970’s with paralleled development in other technological fields. Robust optimization has many applications in statistics, chemical engineering, finance, pharmaceuticals and computer science. In engineering, this theory often is referred to as “Robust Design Optimization’ of “Reliability Based Design”.
## What is Robustness?
Robustness refers to the ability of a system to cope with errors during an execution. It can also be defined as the ability of an algorithm to continue operating despite abnormalities in calculations. Most algorithms try to find a balance between robustness and efficiency/execution time.
## Simple Mathematical Example
$Max 5X + 2Y s.t. cX + dY <= 15 X >= 0 Y >= 0$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 1, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7263015508651733, "perplexity": 1929.2482518642034}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585270.40/warc/CC-MAIN-20211019140046-20211019170046-00260.warc.gz"} |
http://hal.in2p3.fr/in2p3-00639500 | # On transient effects in violent nuclear collisions
Abstract : It is shown that the numerical simulations of the recently developed Boltzmann-Langevin model exhibit large dynamical fluctuations in momentum space during the early stages of heavy-ion collisions, which arise from an interplay between the nuclear mean-field and binary collisions. It is pointed out that this transient behaviour provides an initial seed for the development of density fluctuations, and could strongly influence the particle production cross-sections at subthreshold energies.
Document type :
Journal articles
Nuclear Physics A, Elsevier, 1994, pp.323-334. <10.1016/0375-9474(94)90777-3>
http://hal.in2p3.fr/in2p3-00639500
Contributor : Michel Lion <>
Submitted on : Wednesday, November 9, 2011 - 12:53:18 PM
Last modification on : Thursday, April 23, 2015 - 2:14:36 PM
### Citation
E. Suraud, S. Ayik, M. Belkacem, F.S. Zhang. On transient effects in violent nuclear collisions. Nuclear Physics A, Elsevier, 1994, pp.323-334. <10.1016/0375-9474(94)90777-3>. <in2p3-00639500>
### Metrics
Consultation de la notice | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9073176383972168, "perplexity": 5279.0575277801645}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-27/segments/1435375097204.8/warc/CC-MAIN-20150627031817-00033-ip-10-179-60-89.ec2.internal.warc.gz"} |
https://stats.stackexchange.com/questions/220078/what-is-the-proper-way-to-measure-error-for-an-estimation-algorithm | # What is the proper way to measure error for an estimation algorithm?
Our algorithm is about estimating the true statistic values from a data set. The data set is a table in relational database, we are going to estimate the statistic value for filtered records, like SUM("Sales") WHERE city="New York". We do this because the table is too large to calculate the true answer.
We use relative error for accuracy measurement at first, but we soon noticed that for small values, the error usually exceeds 100% and raises the average error. For example, if the true answer is 3, and my algorithm gives 9, it is a 200% error and will result in a very high average error, even if the other queries are answered properly. So I'm wondering if using relative error is not proper here, because if my algorithm always estimate a very small value, there will be unlikely for my algorithm to give an average error over 100%. It is unfair if my algorithm overestimates the true value.
Please note that I'm not trying to develop an algorithm to do the estimation, but I'm finding a fair measurement to evaluate the accuracy for different estimation algorithms. For example, we can estimate the sum by 1) Sampling from the original data set and estimate the sum with CLT, or 2) Draw a histogram offline and give an approximate answer for specific queries online according to the histogram. My question here is that under the traditional definition of relative error, the algorithm that always give small values tend to benefit more, so I'm looking for another measurement which is fairer.
I use the following formula in the past, but I'm wondering if it has any theories behind it:
$error=abs(x_{estimate}-x_{true})/{max(x_{estimate},x_{true})}$
So is there any better measurement to measure the error for an estimation algorithm?
Thanks!
• Let me ask you if I really understood what your question. Lets suppose you have the data $x_1,\,x_2,...,x_n$. In your example you want to find out the value of $x_1 + x_2 +...+x_n$, but you are not able to perform the whole summation. Is that why you need the approximation? Do the algorithm you created require or use randomness in any sense? – Mur1lo Jun 22 '16 at 3:39
• Can you say more about your situation, your data & your goals? This doesn't make sense to me, & I don't think this question is answerable. – gung - Reinstate Monica Jun 22 '16 at 4:04
• @Mur1lo Yes, the original data set is too large, so we used some kind of algorithm to make an approximation for it. We don't include randomness in our algorithm. – DarkZero Jun 22 '16 at 5:09
• @gung I added some background information for you. I am just wondering if it is reasonable to use relative error to measure the error of an estimation algorithm, because it punishes too much for overestimation... – DarkZero Jun 22 '16 at 5:10
• In the denominator of your error formula why do you have max? Shouldn't it be only the true value? ref: en.wikipedia.org/wiki/Approximation_error – Mur1lo Jun 23 '16 at 3:47
I would suggest adding a "small" number to the denominator of your ratio.
$$error=\frac{|x_{estimate}-x_{true}|}{x_{true}+K}$$
You set $$K$$ equal to a "negligible" amount. For your example, setting $$K=6$$ would give an error of 66% instead of 200% for $$K=0$$.
The number to add will depend on your context and what kind of absolute errors are negligible
There are a lot of measures for error of estimation and the one you provided is a valid one. But since you are working with the sum of random variables, I suggest using normal distribution (supported by the Central Limit Theorem) and instead of calculating once the sum of sales in New York, you’ll have to repeat that algorithm (at least 30 times) including randomness in your selection.
With your sample of 30 "sum of sales" you can use Normal Distribution and not only calculate the Mean Square Error as a good estimator of error, but also calculate probabilities.
Another good news is most of statistical inference is developed for variables with normal distribution.
• The classical CLT applies only to the sample mean, not to the sum. – Mur1lo Jun 22 '16 at 17:38
• Central Theorem Limit it's actually a summary of different convergence laws. In en.wikipedia.org/wiki/Central_limit_theorem says " central limit theorem is any of a set of weak-convergence theorems in probability theory. They all express the fact that a sum of many independent and identically distributed (i.i.d.) random variables (...) will tend to be distributed according to (...) normal distribution" – Camila Burne Jun 22 '16 at 18:12
• By "a sum" the author did not mean ANY sum. The mean is a particular type of sum, just like $\sum(X_i -\bar X)^2/n$ is another sum. The problem is that the variance of $\sum X_i$ goes to infinity and as a consequence it cannot converge in law to any distribution with finite variance. – Mur1lo Jun 22 '16 at 19:10
• The recommendation to repeat an estimator 30 times in order to use a Normal distribution is truly strange. What support can you adduce for that? – whuber Jun 22 '16 at 20:55
• I'm not questioning the 30: I'm questioning the very idea that any replication is needed in the first place! That idea seems to belie a fundamental misconception about sampling and estimation. – whuber Jun 23 '16 at 14:16 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 4, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8738276362419128, "perplexity": 346.22370451330653}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141188146.22/warc/CC-MAIN-20201126113736-20201126143736-00492.warc.gz"} |
http://ncvm3.books.nba.co.za/chapter/unit-4-find-the-general-solution-to-trig-equations/ | Space, shape and measurement: Solve problems by constructing and interpreting trigonometric models
# Unit 4: Find the general solution to trig equations
Dylan Busa
### Unit outcomes
By the end of this unit you will be able to:
• Solve trigonometric equations using a general solution.
## What you should know
Before you start this unit, make sure you can:
• Define the three basic trigonometric ratios of sine, cosine and tangent.
• Solve basic linear equations.
• Calculate with the special angles. Refer to unit 1 of this subject outcome if you need help with this.
• Use the trig reduction formulae. Refer to unit 2 of this subject outcome if you need help with this.
• Draw and work with the CAST diagram to determine in which quadrants each of the trig ratios are positive or negative. Refer to level 2 subject outcome 3.6 unit 1 if you need help with this.
## Introduction
If $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$, what is $\scriptsize \theta$? If you said that $\scriptsize \theta ={{30}^\circ}$ because of your knowledge of special angles from unit 1, you would be absolutely correct and yet still not completely correct! How can this be?
Remember that the trig functions are periodic – they repeat themselves over and over again. We know already, for example, that $\scriptsize \sin {{150}^\circ}=\sin ({{180}^\circ}-{{30}^\circ})=\sin {{30}^\circ}=\displaystyle \frac{1}{2}$ as well. But the function repeats itself again every $\scriptsize {{360}^\circ}$. Therefore, there are infinitely many solutions to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$.
If you have an internet connection, visit this simulation to see all the solutions to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ for the interval $\scriptsize -{{720}^\circ}\le \theta \le {{720}^\circ}$.
You will find that there are eight in total.
All of these solutions are shown in Figure 1.
Therefore, it is not good enough to say that the solution to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ is $\scriptsize \theta ={{30}^\circ}$. Nor can we list all the possible solutions. We need a way to give a general solution that can generate all the possible solutions for $\scriptsize \theta \in \mathbb{R}\text{ }$.
## The general solution for $\scriptsize \sin \theta$
Let’s look at the solutions for $\scriptsize \theta$ for $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ for the interval $\scriptsize -{{720}^\circ}\le \theta \le {{720}^\circ}$ again.
$\scriptsize -{{690}^\circ},-{{570}^\circ},-{{330}^\circ},-{{210}^\circ},{{30}^\circ},{{150}^\circ},{{390}^\circ},{{510}^\circ}$. Can you see any pattern? Look back at Figure 1 to help you.
What if you arrange the solutions in two columns like this:
\scriptsize \begin{align*} -{{690}^\circ}&&-{{570}^\circ}\\ -{{330}^\circ}&&-{{210}^\circ}\\ {{30}^\circ}&&{{150}^\circ}\\ {{390}^\circ}&&{{510}^\circ} \end{align*}
Can you see the pattern now? Hopefully you can see that each solution in each column is separated from the next by $\scriptsize {{360}^\circ}$, the period of the sine function. Look at the first column again. If we use $\scriptsize {{30}^\circ}$ (the answer that a calculator would give us) as the starting angle or the reference angle, look at how we can generate all the other solutions.
\scriptsize \begin{align*}&{{30}^\circ}-2\times {{360}^\circ}-{{690}^\circ}\\&{{30}^\circ}-1\times {{360}^\circ}=-{{330}^\circ}\\&{{30}^\circ}\\&{{30}^\circ}+1\times {{360}^\circ}={{390}^\circ}\end{align*}
We can do the same for the second column of solutions using $\scriptsize {{180}^\circ}-{{30}^\circ}={{150}^\circ}$ as the starting angle.
\scriptsize \begin{align*}&{{150}^\circ}-2\times {{360}^\circ}=-{{570}^\circ}\\&{{150}^\circ}-1\times {{360}^\circ}=-{{210}^\circ}\\&{{150}^\circ}\\&{{150}^\circ}+1\times {{360}^\circ}={{510}^\circ}\end{align*}
So, with just the two starting angles $\scriptsize {{30}^\circ}$ and $\scriptsize {{150}^\circ}$, we can generate every other solution to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ by adding integer ($\scriptsize \mathbb{Z}$) multiples of the period of the sine function i.e. $\scriptsize {{360}^\circ}$.
We write the full or general solution to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ as follows:
$\scriptsize \theta ={{30}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{150}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
### Take note!
We call the answer we get for $\scriptsize \theta$, (usually on a calculator) and from which we generate all the other possible solutions, the reference angle.
### Example 4.1
Determine the general solution for $\scriptsize \sin \theta =0.35$.
Solution
Step 1: Use a calculator to determine the reference angle
\scriptsize \begin{align*}\sin \theta &=0.35\\\therefore \theta &={{20.5}^\circ}\end{align*}
Note: Unless told otherwise, we usually round the reference angle to one decimal place.
Step 2: Use the CAST diagram to determine any other possible solutions
$\scriptsize \sin \theta =0.35$. In other words, sine is positive. Sine is positive in the first and second quadrants. We already have the first quadrant solution (the reference angle of $\scriptsize \theta ={{20.5}^\circ}$). We need to find the second quadrant solution. We know that $\scriptsize \sin ({{180}^\circ}-\theta )=\sin \theta$. Therefore, the second quadrant solution is $\scriptsize {{180}^\circ}-{{20.5}^\circ}={{159.5}^\circ}$.
Step 3: Generate the general solution
$\scriptsize \theta ={{20.5}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{159.5}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
Step 4: Check your general solution
It is always a good idea to check that your final solutions satisfy the original equation. Choose a random value for $\scriptsize k$.
$\scriptsize k=-2$:
\scriptsize \begin{align*}&\theta ={{20.5}^\circ}-2\times {{360}^\circ}\text{ or }\theta ={{159.5}^\circ}-2\times {{360}^\circ}\\&\therefore \theta =-{{699.5}^\circ}\text{ or }\theta =-{{560.5}^\circ}\end{align*}
$\scriptsize \sin (-{{699.5}^\circ})=0.35$
$\scriptsize \sin (-{{560.5}^\circ})=0.35$
Our general solution is correct.
### Example 4.2
Solve for $\scriptsize \theta$ if $\scriptsize 4\sin \theta =-3$ for the interval $\scriptsize [-{{180}^\circ},{{180}^\circ}]$.
Solution
\scriptsize \begin{align*}4\sin \theta =-3&\\\therefore \sin \theta =-\displaystyle \frac{3}{4}&=-0.75\end{align*}
Step 1: Use a calculator to determine the reference angle
When we have a negative ratio, we ignore the sign when finding the reference angle.
\scriptsize \begin{align*}&\sin \theta =0.75\\&\therefore \theta ={{48.6}^\circ}\end{align*}
Step 2: Use the CAST diagram to determine any other possible solutions
Our equation is $\scriptsize \sin \theta =-0.75$. In other words, sine is negative. Sine is negative in the third and fourth quadrants. Our reference angle is $\scriptsize \theta ={{48.6}^\circ}$.
Third quadrant: $\scriptsize \sin ({{180}^\circ}+\theta )=-\sin \theta$. Therefore, the third quadrant solution is $\scriptsize {{180}^\circ}+{{48.6}^\circ}={{228.6}^\circ}$.
Fourth quadrant: $\scriptsize \sin ({{360}^\circ}-\theta )=-\sin \theta$. Therefore, the fourth quadrant solution is $\scriptsize {{360}^\circ}-{{48.6}^\circ}={{311.4}^\circ}$.
Step 3: Generate the general solution
$\scriptsize \theta ={{228.6}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{311.4}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
Step 4: Generate the solution for the specific range
In this instance, we were not asked for the general solution but only for the solutions in $\scriptsize [-{{180}^\circ},{{180}^\circ}]$. We need to use our general solution to generate solutions that fall within this range by adding or subtracting multiples of $\scriptsize {{360}^\circ}$.
$\scriptsize \theta ={{228.6}^\circ}-1\times {{360}^\circ}=-{{131.4}^\circ}\text{or }\theta ={{311.4}^\circ}-1\times {{360}^\circ}=-{{48.6}^\circ}$
Step 5: Check your general solution
It is always a good idea to check that your final solutions satisfy the original equation.
$\scriptsize \sin (-{{131.4}^\circ})=-0.75$
$\scriptsize \sin (-{{48.6}^\circ})=-0.75$
### Exercise 4.1
1. Determine the general solution for $\scriptsize 2\sin \theta =\sqrt{3}$.
2. Solve for $\scriptsize x$ if $\scriptsize 5\sin x=-2$ and $\scriptsize {{0}^\circ}\le x\le {{360}^\circ}$.
The full solutions are at the end of the unit.
## The general solution for $\scriptsize \cos \theta$ and $\scriptsize \tan \theta$
The general solution for $\scriptsize \cos \theta =y$ is basically the same as that for sine. Remember that cosine also has a period of $\scriptsize {{360}^\circ}$. The only difference occurs when you find the quadrants in which cosine is either positive or negative.
The general solution for $\scriptsize \tan \theta =y$ is basically the same as that for sine except that the period of tangent is $\scriptsize {{180}^\circ}$. The other difference occurs when you find the quadrants in which tangent is either positive or negative.
### Example 4.3
Determine the general solution for $\scriptsize 3\cos x=\sin {{14}^\circ}$.
Solution
\scriptsize \begin{align*}3\cos x&=\sin {{14}^\circ}\\\therefore \cos x&=\displaystyle \frac{{\sin {{{14}}^\circ}}}{3}\end{align*}
Step 1: Use a calculator to determine the reference angle
\scriptsize \begin{align*}\cos x & =\displaystyle \frac{{\sin {{{14}}^\circ}}}{3}\\\therefore x & ={{85.4}^\circ}\end{align*}
Step 2: Use the CAST diagram to determine any other possible solutions
Our equation is $\scriptsize \cos x=\displaystyle \frac{{\sin {{{14}}^\circ}}}{3}$. Because $\scriptsize \sin {{14}^\circ} \gt 0$ we know that $\scriptsize \cos x \gt 0$. Cosine is positive in the first and fourth quadrants. Our reference angle is $\scriptsize \theta ={{85.4}^\circ}$.
First quadrant: $\scriptsize \theta ={{85.4}^\circ}$
Fourth quadrant: $\scriptsize \cos ({{360}^\circ}-\theta )=\cos \theta$
$\scriptsize {{360}^\circ}-{{85.4}^\circ}={{274.6}^\circ}$.
Step 3: Generate the general solution
$\scriptsize \theta ={{85.4}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{274.6}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
Step 4: Check your general solution
$\scriptsize k=2$:
$\scriptsize \theta ={{85.4}^\circ}+{{2.360}^\circ}={{805.4}^\circ}\text{ or }\theta ={{274.6}^\circ}+{{2.360}^\circ}={{994.6}^\circ}$
$\scriptsize \cos {{805.4}^\circ}=\displaystyle \frac{{\sin {{{14}}^\circ}}}{3}$
$\scriptsize \sin {{994.6}^\circ}=\displaystyle \frac{{\sin {{{14}}^\circ}}}{3}$
### Example 4.4
Solve for $\scriptsize \alpha$ if $\scriptsize \tan \alpha =-5.2$ and $\scriptsize {{0}^\circ}\le \alpha \le {{360}^\circ}$.
Solution
Step 1: Use a calculator to determine the reference angle
\scriptsize \begin{align*}\tan \alpha&=5.2&&\text{Remember, when finding the reference angle we always use the positive ratio}\\\therefore \alpha&={{79.1}^\circ}\end{align*}
Step 2: Use the CAST diagram to determine any other possible solutions
Our equation is $\scriptsize \tan \alpha =-5.2$. $\scriptsize \tan \alpha \lt 0$.
Second quadrant: $\scriptsize \tan ({{180}^\circ}-\theta )=-\tan \theta$. Therefore, the second quadrant solution is $\scriptsize {{180}^\circ}-{{79.1}^\circ}={{100.9}^\circ}$.
Fourth quadrant: $\scriptsize \tan ({{360}^\circ}-\theta )=-\tan \theta$. Therefore, the fourth quadrant solution is $\scriptsize {{360}^\circ}-{{79.1}^\circ}={{280.9}^\circ}$.
Step 3: Generate the general solution
$\scriptsize \alpha ={{100.9}^\circ}+k{{.180}^\circ}\text{ or }\alpha ={{280.9}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}$
Note: Because the period of tangent is $\scriptsize {{180}^\circ}$, the general solution includes integer multiples of $\scriptsize {{180}^\circ}$. Therefore, it is also possible to generate the general solution from only one angle. $\scriptsize {{280.9}^\circ}={{100.9}^\circ}+1\times {{180}^\circ}$.
The simplest general solution is thus $\scriptsize \alpha ={{100.9}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}$
Step 4: Generate the solution for the specific range
In this instance, we were not asked for the general solution but only for the solutions in$\scriptsize {{0}^\circ}\le \alpha \le {{360}^\circ}$. We need to use our general solution to generate solutions that fall within this range by adding or subtracting multiples of $\scriptsize {{180}^\circ}$.
$\scriptsize \alpha ={{100.9}^\circ}+0\times {{180}^\circ}={{100.9}^\circ}\text{or }\alpha ={{100.9}^\circ}+1\times {{180}^\circ}={{280.9}^\circ}$
Step 5: Check your general solutions
$\scriptsize \tan {{100.9}^\circ}=-5.2$
$\scriptsize \tan {{280.9}^\circ}=-5.2$
### Exercise 4.2
1. Determine the general solution for $\scriptsize 5-3\tan \theta =0$.
2. Solve for $\scriptsize x$ if $\scriptsize 3\cos x-1=-2$ for the interval $\scriptsize [{{0}^\circ},{{360}^\circ}]$.
The full solutions are at the end of the unit.
## Solve more complicated trig equations
In level 3 subject outcome 2.1 units 7, 9 and 11, we learnt about the functions $\scriptsize y=a\sin kx$, $\scriptsize y=a\cos kx$ and $\scriptsize y=a\tan kx$. We saw, for example, that the period of the function $\scriptsize y=\sin 2x$ was no longer $\scriptsize {{360}^\circ}$. The period was actually $\scriptsize \displaystyle \frac{{{{{360}}^\circ}}}{2}={{180}^\circ}$.
### Note
If you have an internet connection, visit this interactive simulation.
Here you will see the solutions to the equation $\scriptsize \sin kx=c$ where you can control the values of $\scriptsize k$ and $\scriptsize c$.
How many solutions are there to $\scriptsize \sin x=0.5$? How many solutions are there to $\scriptsize \sin 2x=0.5$?
Figure 2 shows the solutions to $\scriptsize \sin x=0.5$. As you would expect, these are $\scriptsize x={{30}^\circ}$ and $\scriptsize x={{150}^\circ}$ for the interval $\scriptsize [{{0}^\circ},{{360}^\circ}]$.
Now look at the solutions to $\scriptsize \sin 2x=0.5$ in Figure 3. There are three important things to notice.
1. The period of the graph has halved and the graph repeats twice in the interval $\scriptsize [{{0}^\circ},{{360}^\circ}]$. Therefore, there are double the number of solutions in the same interval.
2. The solution $\scriptsize x={{30}^\circ}$ from before is now $\scriptsize x=\displaystyle \frac{{{{{30}}^\circ}}}{2}={{15}^\circ}$. The solution $\scriptsize x={{150}^\circ}$ from before is now $\scriptsize x=\displaystyle \frac{{{{{150}}^\circ}}}{2}={{75}^\circ}$.
3. Solutions to $\scriptsize \sin x=0.5$ are separated by integer multiples of $\scriptsize {{360}^\circ}$. Solutions to $\scriptsize \sin 2x=0.5$ are seperated by interger multiples of $\scriptsize \displaystyle \frac{{{{{360}}^\circ}}}{2}={{180}^\circ}$.
Therefore, when we solve equations such as $\scriptsize \sin 2\theta =\displaystyle \frac{1}{2}$, we need to modify the general solution to take into account the period of the function is now $\scriptsize {{180}^\circ}$.
So, if the general solution to $\scriptsize \sin \theta =\displaystyle \frac{1}{2}$ is $\scriptsize \theta ={{30}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{150}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$, then the general solution to $\scriptsize \sin 2\theta =\displaystyle \frac{1}{2}$ is $\scriptsize \theta ={{15}^\circ}+k{{.180}^\circ}\text{ or }\theta ={{75}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }$.
The same is true for cosine and tangent equations.
### Example 4.5
Determine the general solution for $\scriptsize \theta$ if $\scriptsize 5\sin 2\theta =3$.
Solution
\scriptsize \begin{align*}5\sin 2\theta & =3\\\therefore \sin 2\theta & =\displaystyle \frac{3}{5}\end{align*}
Step 1: Use a calculator to determine the reference angle
\scriptsize \begin{align*}\sin 2\theta & =\displaystyle \frac{3}{5}\\\therefore 2\theta & ={{36.9}^\circ}\end{align*}
Note: We keep working with the reference angle as $\scriptsize 2\theta$ until we generate the general solution.
Step 2: Use the CAST diagram to determine any other possible solutions
Our equation is $\scriptsize \sin 2\theta =\displaystyle \frac{3}{5}$. $\scriptsize \sin 2\theta \gt 0$. Sine is positive in the first and second quadrants.
First quadrant: $\scriptsize 2\theta ={{36.9}^\circ}$
Second quadrant: $\scriptsize \sin ({{180}^\circ}-\theta )=\sin \theta$
$\scriptsize 2\theta ={{180}^\circ}-{{36.9}^\circ}={{143.2}^\circ}$.
Step 3: Generate the general solution
\scriptsize \begin{align*}2\theta & ={{36.9}^\circ}+k{{.360}^\circ}\text{ or 2}\theta ={{143.2}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }\\\therefore \theta & ={{18.45}^\circ}+k{{.180}^\circ}\text{ or }\theta ={{71.6}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }\end{align*}
Step 4: Check your general solution
$\scriptsize k=2$:
$\scriptsize \therefore \theta ={{18.45}^\circ}+2\times {{180}^\circ}={{378.45}^\circ}\text{ or }\theta ={{71.6}^\circ}+2\times {{180}^\circ}={{431.6}^\circ}$
$\scriptsize \sin (2\times {{378.45}^\circ})=0.6$
$\scriptsize \sin (2\times {{431.6}^\circ})=0.6$
### Example 4.6
Solve for $\scriptsize \theta$ if $\scriptsize \tan (3\theta -{{38}^\circ})=-5$ for the interval $\scriptsize [-{{180}^\circ},{{180}^\circ}]$.
Solution
Step 1: Use a calculator to determine the reference angle
\scriptsize \begin{align*}\tan (3\theta -{{38}^\circ}) & =5\quad \text{Remember, when finding the reference angle, use the positive ratio}\\\therefore 3\theta -{{38}^\circ} & ={{78.7}^\circ}\quad \text{Keep your reference angle in terms of }3\theta -{{38}^\circ}\end{align*}
Note: We keep working with the reference angle as $\scriptsize 3\theta -{{38}^\circ}$ until we generate the general solution.
Step 2: Use the CAST diagram to determine any other possible solutions
Our equation is $\scriptsize \tan (3\theta -{{38}^\circ})=-5$. $\scriptsize \tan (3\theta -{{38}^\circ}) \lt 0$. Tangent is negative in the second and fourth quadrants.
Second quadrant: $\scriptsize \tan ({{180}^\circ}-\theta )=-\tan \theta$
$\scriptsize {{180}^\circ}-{{78.7}^\circ}={{101.3}^\circ}$
Step 3: Generate the general solution
\scriptsize \begin{align*}3\theta -{{38}^\circ} & ={{101.3}^\circ}+k{{.180}^\circ},\text{ }k\in \mathbb{Z}\quad \text{Add }{{38}^\circ}\text{to the angle}\\\therefore 3\theta & ={{139.3}^\circ}+k{{.180}^\circ},\text{ }k\in \mathbb{Z}\quad \text{Divide both the angle and the period by }3\\\therefore \theta &={{46.37}^\circ}+k{{.60}^\circ},\text{ }k\in \mathbb{Z}\end{align*}
Step 4: Generate the solution for the specific range
The interval is $\scriptsize [-{{180}^\circ},{{180}^\circ}]$.
$\scriptsize \theta ={{46.37}^\circ}-3\times {{60}^\circ}=-{{133.63}^\circ}$ or
$\scriptsize \theta ={{46.37}^\circ}-2\times {{60}^\circ}=-{{73.63}^\circ}$ or
$\scriptsize \theta ={{46.37}^\circ}-1\times {{60}^\circ}=-{{13.63}^\circ}$ or
$\scriptsize \theta ={{46.37}^\circ}+0\times {{60}^\circ}={{46.37}^\circ}$ or
$\scriptsize \theta ={{46.37}^\circ}+1\times {{60}^\circ}={{106.37}^\circ}$ or
$\scriptsize \theta ={{46.37}^\circ}+2\times {{60}^\circ}={{166.37}^\circ}$
### Exercise 4.3
1. Determine the general solution for $\scriptsize \cos \left( {\displaystyle \frac{1}{2}x} \right)=0.54$.
2. Solve for $\scriptsize x$ if $\scriptsize 2\sin \left( {\displaystyle \frac{{3x}}{2}+{{{10}}^\circ}} \right) =-1$ for the interval $\scriptsize [-{{180}^\circ},{{180}^\circ}]$.
The full solutions are at the end of the unit.
## Summary
In this unit you have learnt the following:
• How to find the general solution for trig equations involving sine, cosine and tangent and simple angles.
• How to find the general solution for trig equations involving sine, cosine and tangent and more complex angles.
• How to find the solutions to trig equations involving sine, cosine and tangent for specific intervals.
# Unit 4: Assessment
#### Suggested time to complete: 45 minutes
All the questions below have been adapted from NC(V) examination questions.
1. Determine the general solution for $\scriptsize \sin \theta +1=0.3$.
2. Calculate the value/s of $\scriptsize \theta$ if $\scriptsize 2\tan \theta =0.279$ where $\scriptsize \theta \in [{{0}^\circ},{{360}^\circ}]$.
3. Calculate the value/s of $\scriptsize \theta$ if $\scriptsize 5\cos 2\theta =-2.7$ where $\scriptsize \theta \in [{{0}^\circ},{{360}^\circ}]$.
4. Calculate the value/s of $\scriptsize \theta$ if $\scriptsize \tan (3\theta -{{48}^\circ})=3.2$ where $\scriptsize \theta \in [{{0}^\circ},{{180}^\circ}]$.
5. Determine the value/s of $\scriptsize \theta$ in the following equation without a calculator if $\scriptsize {{0}^\circ}\le \theta \le {{360}^\circ}$.
$\scriptsize \sin \theta +\sqrt{2}=-\sin \theta$
The full solutions are at the end of the unit.
# Unit 4: Solutions
### Exercise 4.1
1. .
\scriptsize \begin{align*}2\sin \theta & =\sqrt{3}\\\therefore \sin \theta & =\displaystyle \frac{{\sqrt{3}}}{2}\end{align*}
Ref angle: $\scriptsize \theta ={{60}^\circ}$ (you should have recognised this as a special angle ratio)
$\scriptsize \sin \theta \gt 0$ in first and second quadrant. Therefore, $\scriptsize \theta ={{60}^\circ}\text{ or }\theta ={{180}^\circ}-{{60}^\circ}={{120}^\circ}$.
General solution: $\scriptsize \theta ={{60}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{120}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
2. .
\scriptsize \begin{align*}5\sin x & =-2\\\therefore \sin x & =-\displaystyle \frac{2}{5}\end{align*}
Ref angle: $\scriptsize x={{23.6}^\circ}$
$\scriptsize \sin x \lt 0$ in third and fourth quadrants.
$\scriptsize \theta ={{180}^\circ}+23.6={{203.6}^\circ}\text{ or }\theta ={{360}^\circ}-{{23.6}^\circ}={{336.4}^\circ}$.
General solution: $\scriptsize \theta ={{203.6}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{336.4}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
Specific solution for $\scriptsize {{0}^\circ}\le x\le {{360}^\circ}$: $\scriptsize \theta ={{203.6}^\circ}\text{ or }\theta ={{336.4}^\circ}$
Back to Exercise 4.1
### Exercise 4.2
1. .
\scriptsize \begin{align*}5-3\tan \theta & =0\\\therefore \tan \theta & =\displaystyle \frac{5}{3}\end{align*}
Ref angle: $\scriptsize \theta ={{59}^\circ}$
$\scriptsize \tan \theta \gt 0$ in the first and third quadrants.
$\scriptsize \theta ={{59}^\circ}\text{ or }\theta ={{180}^\circ}+{{59}^\circ}={{239}^\circ}$
General solution: $\scriptsize \theta ={{59}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }$
2. .
\scriptsize \begin{align*}3\cos x-1 & =-2\\\therefore 3\cos x & =-1\\\therefore \cos x & =-\displaystyle \frac{1}{3}\end{align*}
Ref angle: $\scriptsize x={{70.5}^\circ}$
$\scriptsize \cos x \lt 0$ in the second and third quadrants.
$\scriptsize x={{180}^\circ}-{{70.5}^\circ}={{109.5}^\circ}\text{ or }x={{180}^\circ}+{{70.5}^\circ}={{250.5}^\circ}$
General solution: $\scriptsize x={{109.5}^\circ}+k{{.360}^\circ}\text{ or }x={{250.5}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
Specific solution for $\scriptsize [{{0}^\circ},{{360}^\circ}]$: $\scriptsize x={{109.5}^\circ}\text{ or }x={{250.5}^\circ}$
Back to Exercise 4.2
### Exercise 4.3
1. .
\scriptsize \begin{align*}\cos \left( {\displaystyle \frac{1}{2}x} \right) & =0.54\\\therefore \displaystyle \frac{1}{2}x & ={{57.3}^\circ}\end{align*}
Ref angle: $\scriptsize \displaystyle \frac{1}{2}x={{57.3}^\circ}$
$\scriptsize \cos \left( {\displaystyle \frac{1}{2}x} \right) \gt 0$ in the first and fourth quadrants.
$\scriptsize \displaystyle \frac{1}{2}x={{57.3}^\circ}\text{ or }\displaystyle \frac{1}{2}x={{360}^\circ}-{{57.3}^\circ}={{302.7}^\circ}$
General solution:
\scriptsize \begin{align*}\displaystyle \frac{1}{2}x & ={{57.3}^\circ}+k{{.360}^\circ}\text{ or }\displaystyle \frac{1}{2}x={{302.7}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }\\\therefore x & ={{114.6}^\circ}+k{{.720}^\circ}\text{ or }x={{605.4}^\circ}+k{{.720}^\circ},k\in \mathbb{Z}\text{ }\end{align*}
2. .
\scriptsize \begin{align*}2\sin \left( {\displaystyle \frac{{3x}}{2}+{{{10}}^\circ}} \right) & =-1\\\therefore \sin \left( {\displaystyle \frac{{3x}}{2}+{{{10}}^\circ}} \right) &=-\displaystyle \frac{1}{2}\end{align*}
Ref angle: $\scriptsize \left( {\displaystyle \frac{{3x}}{2}+{{{10}}^\circ}} \right) ={{30}^\circ}$
$\scriptsize \sin \left( {\displaystyle \frac{{3x}}{2}+{{{10}}^\circ}} \right) \lt 0$ in the third and fourth quadrants.
$\scriptsize \displaystyle \frac{{3x}}{2}+{{10}^\circ}={{180}^\circ}+{{30}^\circ}={{210}^\circ}\text{ or }\displaystyle \frac{{3x}}{2}+{{10}^\circ}={{360}^\circ}-{{30}^\circ}={{330}^\circ}$
General solution:
\scriptsize \begin{align*}\displaystyle \frac{{3x}}{2}+{{10}^\circ} & ={{210}^\circ}+k{{.360}^\circ}\text{ or }\displaystyle \frac{{3x}}{2}+{{10}^\circ}={{330}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }\\\therefore \displaystyle \frac{{3x}}{2} & ={{200}^\circ}+k{{.360}^\circ}\text{ or }\displaystyle \frac{{3x}}{2}={{320}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }\\\therefore x & ={{133.33}^\circ}+k{{.240}^\circ}\text{ or }\displaystyle \frac{{3x}}{2}={{213.33}^\circ}+k{{.240}^\circ},k\in \mathbb{Z}\text{ }\end{align*}
Specific solution for $\scriptsize [-{{180}^\circ},{{180}^\circ}]$:
$\scriptsize x ={{133.33}^\circ}-1\times {{240}^\circ}=-{{106.67}^\circ}$ or
$\scriptsize x ={{133.33}^\circ}+0\times {{240}^\circ}={{133.33}^\circ}$ or
$\scriptsize x ={{213.33}^\circ}-1\times {{240}^\circ}=-{{26.67}^\circ}$
Back to Exercise 4.3
### Unit 4: Assessment
1. .
\scriptsize \begin{align*}\sin \theta +1 & =0.3\\\therefore \sin \theta & =-0.7\end{align*}
Ref angle: $\scriptsize \theta ={{44.4}^\circ}$
$\scriptsize \sin \theta \lt 0$: $\scriptsize \theta ={{180}^\circ}+{{44.4}^\circ}={{224.4}^\circ}\text{ or }\theta ={{360}^\circ}-{{44.4}^\circ}={{315.6}^\circ}$
General solution: $\scriptsize \theta ={{224.4}^\circ}+k\text{.36}{{\text{0}}^\circ}\text{ or }\theta ={{315.6}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }$
2. .
\scriptsize \begin{align*}2\tan\theta&=0.279\\\therefore \tan\theta&=0.1395\end{align*}
Ref angle: $\scriptsize \theta ={{8.0}^\circ}$
$\scriptsize \tan \theta \gt 0:$ $\scriptsize \theta ={{8.0}^\circ}\text{ or }\theta ={{180}^\circ}+{{8.0}^\circ}={{188}^\circ}$
General solution: $\scriptsize \theta ={{8.0}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }$
Specific solution for $\scriptsize \theta \in [{{0}^\circ},{{360}^\circ}]$:
$\scriptsize \theta ={{8}^\circ}+0\times {{180}^\circ}={{8}^\circ}$ or
$\scriptsize \theta ={{8.0}^\circ}+1\times {{180}^\circ}={{188.0}^\circ}$
3. .
\scriptsize \begin{align*}5\cos2\theta&=-2.7\\\therefore \cos2\theta&=-0.54\end{align*}
Ref angle: $\scriptsize 2\theta ={{57.3}^\circ}$
$\scriptsize \cos 2\theta \lt 0$: $\scriptsize 2\theta ={{180}^\circ}-{{57.3}^\circ}={{122.7}^\circ}\text{ or }2\theta ={{180}^\circ}+{{57.3}^\circ}={{237.3}^\circ}$
General solution:
\scriptsize \begin{align*}2\theta ={{122.7}^\circ}+k{{.360}^\circ}\text{ or }2\theta ={{237.3}^\circ}+k{{.360}^\circ},k\in \mathbb{Z}\text{ }\\\therefore \theta ={{61.35}^\circ}+k{{.180}^\circ}\text{ or }\theta ={{118.65}^\circ}+{{180}^\circ},k\in \mathbb{Z}\text{ }\end{align*}
Specific solution for $\scriptsize \theta \in [{{0}^\circ},{{360}^\circ}]$:
$\scriptsize \theta ={{61.35}^\circ}+0\times {{180}^\circ}={{61.35}^\circ}$ or
$\scriptsize \theta ={{61.35}^\circ}+1\times {{180}^\circ}={{241.35}^\circ}$ or
$\scriptsize \theta ={{118.65}^\circ}+0\times {{180}^\circ}={{118.65}^\circ}$ or
$\scriptsize \theta ={{118.65}^\circ}+1\times {{180}^\circ}={{298.65}^\circ}$
4. $\scriptsize \tan (3\theta -{{48}^\circ})=3.2$
Ref angle: $\scriptsize 3\theta -{{48}^\circ}={{72.6}^\circ}$
$\scriptsize 3\theta -{{48}^\circ}={{72.6}^\circ}\text{ or }3\theta -{{48}^\circ}={{180}^\circ}+{{72.6}^\circ}={{252.6}^\circ}$:
General solution:
\scriptsize \begin{align*}3\theta -{{48}^\circ} & ={{72.6}^\circ}+k{{.180}^\circ}\text{ or }3\theta -{{48}^\circ}={{252.6}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }\\\therefore 3\theta & ={{120.6}^\circ}+k{{.180}^\circ}\text{ or }3\theta ={{300.6}^\circ}+k{{.180}^\circ},k\in \mathbb{Z}\text{ }\\\therefore \theta & ={{40.2}^\circ}+k{{.60}^\circ}\text{ or }\theta ={{100.2}^\circ}+k{{.60}^\circ},k\in \mathbb{Z}\text{ }\end{align*}
But $\scriptsize {{40.2}^\circ}+1\times {{60}^\circ}={{100.2}^\circ}$
Therefore, simplest general solution is $\scriptsize \theta ={{40.2}^\circ}+k{{.60}^\circ},k\in \mathbb{Z}\text{ }$
Specific solution for $\scriptsize \theta \in [{{0}^\circ},{{180}^\circ}]$:
$\scriptsize \theta ={{40.2}^\circ}+0\times {{60}^\circ}={{40.2}^\circ}$ or
$\scriptsize \theta ={{40.2}^\circ}+1\times {{60}^\circ}={{100.2}^\circ}$ or
$\scriptsize \theta ={{40.2}^\circ}+2\times {{60}^\circ}={{160.2}^\circ}$
5. .
\scriptsize \begin{align*}\sin \theta +\sqrt{2} & =-\sin \theta \\\therefore 2\sin \theta & =-\sqrt{2}\\\therefore \sin \theta & =-\displaystyle \frac{{\sqrt{2}}}{2}=-\displaystyle \frac{{\sqrt{2}}}{{\sqrt{2}\times \sqrt{2}}}=-\displaystyle \frac{1}{{\sqrt{2}}}\end{align*}
Ref angle: $\scriptsize \theta ={{45}^\circ}$
$\scriptsize \sin \theta \lt 0$: $\scriptsize \theta ={{180}^\circ}+{{45}^\circ}={{225}^\circ}\text{ or }\theta ={{360}^\circ}-{{45}^\circ}={{315}^\circ}$
General solution: $\scriptsize \theta ={{225}^\circ}+k{{.360}^\circ}\text{ or }\theta ={{315}^\circ}+k{{.360}^\circ}$
Specific solution for $\scriptsize {{0}^\circ}\le \theta \le {{360}^\circ}$:
$\scriptsize \theta ={{225}^\circ}+{{0.360}^\circ}={{225}^\circ}$ or
$\scriptsize \theta ={{315}^\circ}+{{0.360}^\circ}={{315}^\circ}$
Back to Unit 4: Assessment | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9734927415847778, "perplexity": 1453.3177207882998}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572215.27/warc/CC-MAIN-20220815235954-20220816025954-00483.warc.gz"} |
https://www.neetprep.com/question/25821-pressure-greater-atmospheric-pressure-applied-solution-itswater-potential-Increases-Decreases-Remains-Becomes-zero/53-Botany/630-Transport-Plants | If a pressure greater than atmospheric pressure is applied to a solution, its water potential:
1. Increases
2. Decreases
3. Remains same
4. Becomes zero | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9191609621047974, "perplexity": 3381.7405940779504}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370506121.24/warc/CC-MAIN-20200401192839-20200401222839-00455.warc.gz"} |
https://mathematica.stackexchange.com/questions/47449/how-do-i-make-the-color-of-arrowheads-in-a-graph-different-from-the-colors-of-th | # How do I make the color of arrowheads in a graph different from the colors of the arrows?
I'm graphing a Markov process
mp = DiscreteMarkovProcess[{1, 0, 0}, ({
{0.6, 0.1, 0.3},
{0.2, 0.7, 0.1},
{0.3, 0.3, 0.4}
})];
and would like to have arrows whose thicknesses corresponds to the transition probabilities, with arrowheads of a different color in the exact center of each edge. But all my attempts end up a mess.
g = Graph[mp];
Scan[(PropertyValue[{g, #}, EdgeLabels] =
PropertyValue[{g, #}, "Probability"]) &, EdgeList[g]];
Scan[(PropertyValue[{g, #}, EdgeStyle] =
Thickness[PropertyValue[{g, #}, "Probability"]/20]]) &,
EdgeList[g]];
g
The thick edges leave gaps between their ends and the nodes of the graph, and I can't figure out how to change the color of the arrow heads so that they stand out against the color of the edges.
How can I change the color of the arrowheads in my figure. How can I avoid the gaps that appear between nodes and the ends of the edges?
• Take a look at EdgeShapeFunction. – wxffles May 7 '14 at 22:47
• @wxffles: Looks intriguing; but I'm not sure where to go with it. It seems to amount to "build it from scratch". – orome May 7 '14 at 23:21
Using an EdgeShapeFunction seems to do what you want. Adapting from the examples in the help:
ef[pts_List, e_] :=
Arrow[pts]}
g = Graph[mp];
Scan[(PropertyValue[{g, #}, EdgeLabels] =
PropertyValue[{g, #}, "Probability"]) &, EdgeList[g]];
Scan[(PropertyValue[{g, #}, EdgeStyle] =
Directive[GrayLevel[.7], Thickness[PropertyValue[{g, #}, "Probability"]/20]]) &,
EdgeList[g]];
Scan[(PropertyValue[{g, #}, EdgeShapeFunction] = ef) &, EdgeList[g]];
g
It's a bit ugly, with mysterious red dots within the arrowheads. But this only reflects how little time I've put into it. With some competence and patience I suspect it could do what you want.
Edit: Something nicer:
ef[pts_List, e_] := {Arrowheads[{{0.02, 0.65,
Graphics@{Red, EdgeForm[Gray], Polygon[{{-1.5, -1}, {1.5, 0}, {-1.5, 1}}]}
}}], Arrow[pts]}
• Is there a way to keep the arc shapes of the original? – orome May 8 '14 at 0:47
• Not easily as far as I can tell. It's just using the points that it gets passed. I'm not sure what the default EdgeShapeFunctions do to it. – wxffles May 8 '14 at 1:05
• @wxffles How to access the built-in set of arrow heads is described here. – Alexey Popkov May 8 '14 at 7:09
If you don't mind having a Graphics object, you can replace the Arrowheads directives with wxffles's Arrowheads specification, and get to keep the arc shapes of the orginial g:
arrowheads = Arrowheads[{{0.02, 0.65, Graphics@{Red, EdgeForm[Gray],
Polygon[{{-1.5, -1}, {1.5, 0}, {-1.5, 1}}]}}}];
g2 = Show[g] /. TagBox -> (# &) /. _Arrowheads :> arrowheads
If you have to have a Graph object, you can extract the edge primitives from g2 and use them as EdgeShapeFunction for g:
edgehapefunctions = Function /@
Cases[g2[[1]], {dirs___, _Arrowheads, _ArrowBox}, {0, Infinity}];
SetProperty[g, EdgeShapeFunction -> Thread[EdgeList[g] -> edgehapefunctions]] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2472797930240631, "perplexity": 4429.338296535963}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038076819.36/warc/CC-MAIN-20210414034544-20210414064544-00404.warc.gz"} |
https://www.physicsforums.com/threads/textbook-for-learning-pdes-applied-to-physics.848409/ | # Calculus Textbook for learning PDE's applied to physics?
1. Dec 15, 2015
### Vannay
Took a graduate level mathematical methods for physics course and came out the other side feeling a bit lacking in solving stuff like the heat equation, wave equation, laplaces equation and so on. I'm still unsure of the Green's Function method for them, how to look at them with Fourier series, and so on.
The textbook we used was Goldbart and Stone which often would introduce the Green Function method for a given PDE by saying "So here's the solution" and then showing it is. That doesn't help when I'm taking a test that says solve this diffusion PDE given these certain boundary conditions.
2. Dec 15, 2015
### Dr Transport
Last edited by a moderator: May 7, 2017
3. Apr 19, 2016
### UnivMathProdigy
4. Apr 20, 2016
### deskswirl
Draft saved Draft deleted
Similar Discussions: Textbook for learning PDE's applied to physics? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8612613081932068, "perplexity": 1828.498363848379}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886116921.70/warc/CC-MAIN-20170823000718-20170823020718-00540.warc.gz"} |
https://academia.stackexchange.com/questions/86701/where-to-define-a-symbol-that-also-has-an-abbreviation | # Where to define a symbol that also has an abbreviation
I have a symbol μ, which is the linear attenuation coefficient for a material (X-ray tomography). I've already defined that symbol in my document's list of symbols, but the problem is that I also refer to it by its abbreviation, LAC, in my text (LAC is well known in the field, hence I prefer keeping it, only using μ in equations).
Should I add that abbreviation to the list of abbreviations, resulting in their being two entries for linear attenuation coefficient, one in the list of symbols and one in the list of abbreviations, or should I just leave it in the list of symbols?
If you actually have significant explanation beyond just expanding the abbreviation, I recommend putting that in the list of abbreviations and using a cross-reference from the list of symbols. Just like an index can have "attenuation coefficient, linear -- see linear attenuation coefficient", your lists of abbreviations and symbols could have, respectively,
LAC, linear attenuation coefficient, symbol \mu. The linear attenuation coefficient applies to materials where absorbance dominates scattering as an attenuation mechanism, and total transmission energy follows Lambert's Law.
If there's no additional explanation, then both entries can be complete and short and a hyperlink would be pointless.
LAC, linear attenuation coefficient, symbol \mu
\mu, linear attenuation coefficient, abbreviated LAC
• My list of symbols actually has more explanations in it than the list of abbreviations, so I'd prefer to do the reverse of your first suggestion - put the long description in the list of symbols with a link to the abbreviation. Mar 20 '17 at 10:55
• That's perfectly valid as well. Mar 20 '17 at 14:19 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8179872632026672, "perplexity": 1089.7936203013276}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358078.2/warc/CC-MAIN-20211127013935-20211127043935-00153.warc.gz"} |
http://tex.stackexchange.com/questions/5541/why-mathtools-does-not-work-for-showing-only-equations-which-are-referred-to-in | # why mathtools does not work for showing only equations which are referred to in the text?
I am using mathtools in the following way:
\usepackage{mathtools}
\mathtoolsset{showonlyrefs,showmanualtags}
Then, to refer to equations I use \refeq{equation}.
What happens is that there is a numbering for the equation that appears in the text, but the (Eq-Number) does not appear next to the equation itself. In fact, there are no (Eq-Number) for any of the equations.
Any ideas what could cause that? Is there a way to force to have an equation number next to an equation?
Edit
Minimal example:
\documentclass[11pt,letterpaper]{article}
\usepackage{latexsym}
\usepackage{times}
\usepackage{amsfonts,eucal,amsbsy,amsthm,amsopn,amssymb}
\usepackage{color}
\usepackage{graphicx}
\usepackage{array}
\usepackage{url}
\usepackage{mathtools}
\mathtoolsset{showonlyrefs,showmanualtags}
\begin{document}
\begin{eqnarray}
A & = & B \label{eq:first}
\end{eqnarray}
see Equation ~\refeq{eq:first}
\end{document}
-
How do you define your equations? You should wrap them in $$...$$ (or \begin{eqnarray} ... \end{eqnarray} depending if you have one or more rows you want to number...) - maybe you're just wrapping them in or something? – Tomas Lycken Nov 17 '10 at 19:29
@Tomas: No eqnarray, please :-) – Joseph Wright Nov 17 '10 at 19:36
A complete minimal example might be useful. – Harald Hanche-Olsen Nov 17 '10 at 19:40 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 1, "x-ck12": 0, "texerror": 0, "math_score": 0.7209203839302063, "perplexity": 1058.1480304062752}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413558067214.90/warc/CC-MAIN-20141017150107-00367-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://peltarion.com/knowledge-center/documentation/peltarion-connectors/model-download/model-download-for-uipath | UIPath is a Robotic Process Automation (RPA) platform which makes it easy to build, manage and deploy software for automation that emulates human actions interacting with software. As a part of their platform they offer the AI Center which let users upload machine learning models and user them within their RPA workflows.
This page will take you through the steps of how to package the TensorFlow SavedModel, which you can download from the Pletarion Platform, and deploy it to UIPath. This example uses the MNIST classifier as the model.
## Prerequisites
• Set up a Python environment and install tensorflow 2.5.0 with pip install tensorflow==2.5.0
• Download a model in the SavedModel format from the Peltarion Platform
## Converting a Peltarion Platform SavedModel to a UIPath ML Package
In accordance with the UIPath documentation, an ML Package consists of three parts:
1. The ML model, in our case the TensorFlow SavedModel
2. A main.py file with a class Main with an init method and a predict method
3. A requirements.txt containing required dependencies for running the ML Package
Let’s start by creating our requirements.txt. You will only need to add two dependencies to your file
tensorflow==2.5.0
tensorflow-text==2.5.0
We need tensorflow package to load the SavedModel into our python code. The tensorflow-text is needed in the case that the SavedModel is working with text input.
Next up we’ll create our main.py file. As mentioned earlier the ML Package requires this file to contain a class called Main which has a constructor method called init that takes no arguments and a method predict that takes the model input as an argument. In our case, the input will be the binary data if a file since we are working with a MNIST Classifier model. In the UIPath documentation you can read more about what kind of inputs the MLPackage can recieve.
Lets start by importing the packages that we require
import json
import tensorflow as tf
from .utils.parse_input import Features
We will use the Features class to load the feature_mapping.json file that is bundled together with the exported model. This file contains information about the input and output features of the model and the Features class will help us convert features listed by their names into something that the exported model will understand.
The next step is to add the Main class into the main.py file.
class Main(object):
_base_model_path = "./exported_model"
_graph_signature = "serving_default"
def __init__(self):
self._features = Features(feature_mapping_file_path=f"{self._base_model_path}/feature_mapping.json")
self._predict = self._model.signatures[self._graph_signature]
def _build_input(self, X):
example_tensor = self._features.serialize_data({
"image": X
})
example_tensor = tf.expand_dims(example_tensor, -1)
return example_tensor
def _build_output(self, outputs):
result = {}
for feature_id, data in outputs.items():
feature_label = self._features.get_feature_label(feature_id)
out = data.numpy().tolist()[0]
result[feature_label] = {label:prob for label, prob in zip(meta, out)}
else:
result[feature_label] = out
return result
def predict(self, X):
example_tensor = self._build_input(X)
outputs = self._predict(example_tensor)
result = self._build_output(outputs)
return json.dumps(result)
As mentioned earlier this file has the init method where we load our model and create an instance of the Features class. With the help of _build_input and _build_output the predict method builds a tf.train.Example, run it through the SavedModel and returns the result as a JSON string.
Finally, we can add the following code at the end of main.py for local testing.
if __name__ == '__main__':
with open('./mnist-3.png', 'rb') as input_file:
m = Main()
print(m.predict(file_bytes))
With this, you can run python main.py and it should be able to run a prediction on mnist-3.png if this file exists in the same folder as your main.py.
### Creating the ML Package
Now that you have your requirements.txt, main.py and your exported SavedModel you are ready to create your ML Package. This is done by creating a zip file with these 3 artifacts. Before your create your zip file check that you have the following folder structure:
my_package/
├── requirements.txt
├── main.py
└── exported_model
├── feature_mapping.json
├── saved_model
├── assets
├── saved_model.pb
└── variables
├── variables.data-00000-of-00001
└── variables.index | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2179623395204544, "perplexity": 4657.999319993681}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964361169.72/warc/CC-MAIN-20211202054457-20211202084457-00035.warc.gz"} |
https://www.physicsforums.com/threads/abstract-number-of-for-loops.907163/ | # Python Abstract number of for loops
1. Mar 10, 2017
### ChrisVer
Hello, well I am not sure how to search for this online, but I raise this question here:
Suppose that I have several bins of let's say cuts, here I list 3 but the main idea is to make their numbers tunable by the user:
Code (Python):
cut1 = { "p10" : "p <= 10" ,
"11p20 " : "10<p && p<=20" ,
"21p " : "p>20" ,
}
cut2 = { "BoolPass" : "bool" ,
"BoolFail" : "!bool" ,
}
cut3 = { "High" : "T>=0" ,
"Low" : "T<0",
}
and I want to combine all of them together
Code (Python):
cut_comb = dict()
for cutname1,cut1 in cut1.items():
cut_comb[cutname1] =dict()
for cutname2,cut2 in cut2.items():
cut_comb[cutname1][cutname2] =dict()
for cutname3,cut3 in cut3.items():
cut_comb[cutname1][cutname2][cutname3] = add_cuts( [cut1,cut2,cut3] , name="{}_{}_{}".format(cutname1,cutname2,cutname3) )
Where add_cuts is just a function which loops over the cut expression and concatenates the cut expressions approriately...eg:
cut_comb["p10"]["BoolPass"]["High"] would be: "(p<=10)&&(bool)&&(T<0)"
How could I make the so ugly for-in-for-in-for loop look better [and also be able to change some cuts, eg remove the cut3, without having to rewrite the code]... I was thinking about using recursion on a list that contains [cut1,cut2,cut3], but I don't know I get stuck in the logic somewhere, in particular the increasing dict type of cut_comb...maybe I could change the whole name of the key? instead of having 3 keys for example, to have only one with concatenated the expressions, eg:
cut_comb["p10_BoolPass_High"] would be: "(p<=10)&&(bool)&&(T<0)"
But still I'm not sure.
Last edited: Mar 10, 2017
2. Mar 10, 2017
### Staff: Mentor
It's not clear to me what you're trying to do, especially the creation of a dictionary that you would have to drill into so deeply. Can you provide an example of a scenario that would require what you're trying to do?
3. Mar 10, 2017
### ChrisVer
For example suppose you want to draw the efficiencies in different detector parts (eg in eta), so you'll have to have a cut that separates the detector into $|\eta|< X$ and $|\eta| >X$.
Then again you might want to look into different pt ranges, so you will have the cuts $p_T < Y$ , $Y<p_T < Z$ , $p_T>Z$...
This already tells you that you will have 2*3 = 6 efficiency plots... namely the $h(|\eta|<X , p_T < Y) ~,~h(|\eta|>X, p_T < Y)~,~...$ which are taken (in my case) by applying the cut on my ntuples.
and in a similar manner you want to keep adding or maybe removing cuts... (that's why the number of the for loops in the piece of code I wrote should be a variable).
The histograms are obtained mainly by applying the TTree::Draw() method, where you specify which variable you want to take from the tree (eg you want to calculate the efficiency vs the phi) streamed into a pre-set histogram and the cut selection... so eg:
Code (Python):
mytree.Draw( "jet_phi>>hpass", "selection"+"&&pass" )
mytree.Draw( "jet_phi>>htotal", "selection")
h_eff = some_method_to_get_eff_from(hpass,htotal)
the selection will of course be different everytime (specified by my comb_cut).
One maybe unclear thing is that the values of my cut_i dictionaries are not strings, but objects of some type, call it Cut (pretty similar to TCut), that's why I said that add_cuts is dealing approriately with them.
Last edited: Mar 10, 2017
4. Mar 10, 2017
### Staff: Mentor
They sure look like strings to me.
Code (Python):
cut2 = { "BoolPass" : "bool" ,
"BoolFail" : "!bool" ,
}
The first key is "BoolPass", a string, and its value is "bool", another string. So cut2["BoolPass"] evaluates to "bool".
It will take me some time to digest the rest of your post.
5. Mar 10, 2017
### ChrisVer
Well, the full glory one is:
Code (Python):
fout= ROOT.TFile("Save_Eff_Histos.root","RECREATE")
#list of cuts
cut_lowTrkMultiplicity = Cut("low_track_multi", "jet_n_tracks<3")
cut_highTrkMultiplicity= Cut("high_track_multi", "jet_n_tracks >=3")
cut_eta_endcap = Cut("endcap", "abs(jet_eta)>1.5")
cut_eta_barrel = Cut("barrel", "abs(jet_eta)<1.5")
cut_low_pt = Cut("low_pt_less100", "jet_pt<100.")
cut_med_pt = Cut("med_pt_100_300", "jet_pt>=100. && jet_pt<300.")
cut_high_pt = Cut("high_pt_greater300", "jet_pt>=300.")
cut_passBjet = Cut("bjet", "jet_b_tag==1")
#group them
cuts_pt = { "pt_high" : cut_high_pt ,
"pt_med " : cut_med_pt ,
"pt_low" : cut_low_pt ,
}
cuts_eta = { "Barrel" : cut_eta_barrel,
"Endcap" : cut_eta_endcap ,
}
cuts_trackMultiplicity = { "High" : cut_highTrkMultiplicity,
"Low" : cut_lowTrkMultiplicity ,
}
cuts_comb = dict()
h_pass = dict()
h_total = dict()
gr_eff = dict()
for eta_name, eta in cuts_eta.items(): # Barrel and Endcap
cuts_comb[eta_name]=dict()
h_pass[eta_name]=dict()
h_total[eta_name]=dict()
gr_eff[eta_name] =dict()
for ntracks_name, ntracks in cuts_trackMultiplicity.items(): #Low and High Ntracks
cuts_comb[eta_name][ntracks_name]=dict()
h_pass[eta_name][ntracks_name]=dict()
h_total[eta_name][ntracks_name]=dict()
gr_eff[eta_name][ntracks_name]=dict()
for ptRange_name, ptRange in cuts_pt.items(): # Low,Med or High Pt's
#obtain cuts to use
cuts_comb[eta_name][ntracks_name][ptRange_name] = add_cuts( [eta,ntracks,ptRange] , "{}_{}_{}".format(eta_name, ntracks_name, ptRange_name) )
cuts_total = cuts_comb[eta_name][ntracks_name][ptRange_name]
cuts_pass = add_cuts( [cuts_total , cut_passBjet] , cuts_total.name + "_pass" )
#get histograms
h_pass[eta_name][ntracks_name][ptRange_name] = mysame.getHistogram(var="jet_phi", cuts=cuts_pass, name="h_"+cuts_pass.name )
h_total[eta_name][ntracks_name][ptRange_name] = mysame.getHistogram(var="jet_phi", cuts=cuts_total, name="h_total_"+cuts_total.name )
#get efficiency graph
gr_eff[eta_name][ntracks_name][ptRange_name] = ROOT.TGraphAsymmErrors( h_pass[eta_name][ntracks_name][ptRange_name] , h_total[eta_name][ntracks_name][ptRange_name], "cl=0.683 b(1,1) mode" )
gr_eff[eta_name][ntracks_name][ptRange_name].SetTitle("h_eff_"+cuts_total.name)
#save them in an output file
fout.WriteTObject( gr_eff[eta_name][ntracks_name][ptRange_name] )
and on that suppose I want to add, or remove one of my separations (eg pt is doing nothing, so better remove it =remove a for loop and change everything in the remaining ones appropriately - or maybe the Nvertices might affect the efficiency: add bins of Nvertex=add an extra for loop )... it makes it tiring, dangerous and so inefficient.
Last edited: Mar 10, 2017
6. Mar 10, 2017
### wle
I didn't follow all the details, but does this do something close to what you want?
Code (Python):
from itertools import product
from functools import reduce
def tree_set(tree, indices, value):
"""Set 'tree[i0][i1]...' to 'value' for i0, i1, ... in 'indices'."""
deepest = reduce(lambda t, i: t[i], indices[:-1], tree)
deepest[indices[-1]] = value
def build_tree(concatenator, *cuts):
"""Build tree of cuts using supplied concatenator function."""
tree = {}
for cuts_head in (cuts[:n] for n in range(1, len(cuts))):
tree_set(tree, keys, {})
for keys in product(*cuts):
item = concatenator(cut[key] for cut, key in zip(cuts, keys))
tree_set(tree, keys, item)
return tree
# Example:
def concat_items(items):
"""Surround items in () and concatenate them separated by ' && '."""
return ' && '.join('({})'.format(i) for i in items)
cut1 = {"p10": "p <= 10",
"11p20": "10 < p && p <= 20",
"21p": "p > 20"}
cut2 = {"BoolPass": "bool",
"BoolFail": "!bool"}
cut3 = {"High": "T >= 0",
"Low": "T < 0"}
cut_tree = build_tree(concat_items, cut1, cut2, cut3)
print(cut_tree["p10"]["BoolPass"]["High"])
# ...this prints "(p <= 10) && (bool) && (T >= 0)".
This way there's nothing special in there being three "cuts" dictionaries in the example.
EDIT: Put the tree-building stuff in a function that accepts a concatenator function and an arbitrary number of "cuts" dictionaries.
EDIT 2: It's also possible to build up the tree recursively, as has been mentioned a couple of times, e.g. something like:
Code (Python):
def build_helper(items, concatenator, cuts):
if len(cuts) == 0:
return concatenator(items)
else:
tree = {}
for k, v in cuts[0].items():
tree[k] = build_helper(items + [v], concatenator, cuts[1:])
return tree
def build_tree(concatenator, *cuts):
"""Build tree of cuts using supplied concatenator function."""
return build_helper([], concatenator, cuts)
In this case the two imports aren't necessary. You also need to accumulate the values you've found as you go deeper into the recursion, as @SlowThinker mentioned.
I don't know if one method is significantly better than the other.
Last edited: Mar 10, 2017
7. Mar 10, 2017
### SlowThinker
First try to make all levels look equal, i.e. instead of doing nothing on higher levels and accessing cut_comb[cut1][cut2][cut3] at the lowest level, make a temporary variable to hold dict1=cut_comb[cut1], another to hold dict2=dict1[cut2] etc. Same with the strings, don't do all of the concatenation at the bottom level.
Once the structure is more regular, it should be easier to transform it into a recursive function. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.46373283863067627, "perplexity": 10175.53122564168}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257650993.91/warc/CC-MAIN-20180324190917-20180324210917-00209.warc.gz"} |
https://mathzsolution.com/is-the-family-of-probabilities-generated-by-a-random-walk-on-a-finitely-generated-amenable-group-asymptotically-invariant/ | # Is the family of probabilities generated by a random walk on a finitely generated amenable group asymptotically invariant?
Is the family of probabilities $\mu^n$ (convolution) generated by a random walk $\mu$ on a finitely generated amenable group $G$ asymptotically invariant ($\|g\mu^n-\mu\|_{L^1}\to 0$ for any $g\in G$)?
I am not familiar with random walks on amenable groups. Please indicate reference on the subject. | {"extraction_info": {"found_math": true, "script_math_tex": 5, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.27044498920440674, "perplexity": 197.19258560944863}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711394.73/warc/CC-MAIN-20221209080025-20221209110025-00557.warc.gz"} |
http://mathhelpforum.com/calculus/92748-chain-rule.html | # Math Help - chain rule
1. ## chain rule
Is the derivative of $q(x)=x(2x+3)^{3/2}$
$q'(x)=(5x+3)\sqrt{2x+3}$ ?
In case you guys haven't noticed yet, I'm checking my homework. So, if the answer is wrong, just tell me that it's wrong, or give me a hint. I want to do the actual problems by myself.
2. looks good!
3. Originally Posted by VonNemo19
Is the derivative of $q(x)=x(2x+3)^{3/2}$
$q'(x)=(5x+3)\sqrt{2x+3}$ ?
In case you guys haven't noticed yet, I'm checking my homework. So, if the answer is wrong, just tell me that it's wrong, or give me a hint. I want to do the actual problems by myself.
Yes. Factorise the output from here to see that: differentiate x (2x + 3)^(3/2) - Wolfram|Alpha
4. Originally Posted by mr fantastic
Yes. Factorise the output from here to see that: differentiate x (2x + 3)^(3/2) - Wolfram|Alpha
Huh... You learn somthing new every day. Thanks. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 4, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8509431481361389, "perplexity": 1060.0011036575847}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049276537.37/warc/CC-MAIN-20160524002116-00132-ip-10-185-217-139.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/torque-on-an-anemometer.56432/ | # Torque on an anemometer
1. Dec 12, 2004
### ponjavic
Is it possible to calculate the torque on an anemometer, of radius x with cupradius y, depending on the wind speed?
If not is there a similar horizontally rotating device with which you can calculate the torque?
2. Dec 12, 2004
### ceptimus
If the anemometer is turning at a constant speed, and we assume that the bearings it is turning on are frictionless, then the torque is zero. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9811456799507141, "perplexity": 1531.7060877151355}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281069.89/warc/CC-MAIN-20170116095121-00133-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://proofwiki.org/wiki/Volume_of_Sphere/Proof_by_Archimedes/Historical_Note | # Volume of Sphere/Proof by Archimedes/Historical Note
## Historical Note on Archimedes' Proof of Volume of Sphere
The volume of the sphere was proved by Archimedes in around $250$ BCE.
His proof appears as Proposition $33$ in his On the Sphere and Cylinder.
In the version given here, the notation has been brought up to date.
He also describes in detail how he arrived at this result in The Method.
In his words:
I am persuaded that this method will be of no little service to mathematics. For I can see that once it is understood and established, it will be used to discover other theorems which have not yet occurred to me, by other mathematicians, now living or yet unborn.
-- Archimedes: The Method
It can be argued that this was the point integral calculus was first invented.
Tradition has it that he asked his friends to mark his tombstone with the representation of a sphere inscribed within a cylinder, to commemorate this achievement.
This was done at the order of Marcus Claudius Marcellus, the Roman general who finally defeated the City of Syracuse in $212$ BCE. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7303544282913208, "perplexity": 1004.5767563273397}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652663039492.94/warc/CC-MAIN-20220529041832-20220529071832-00471.warc.gz"} |
http://parabix.costar.sfu.ca/changeset/2505/docs/Working/icXML/multithread.tex | Ignore:
Timestamp:
Oct 19, 2012, 6:56:35 PM (7 years ago)
Message:
more edits
File:
1 edited
Legend:
Unmodified
r2502 \section{Leveraging SIMD Parallelism for Multicore: Pipeline Parallelism} %\section{Leveraging SIMD Parallelism for Multicore: Pipeline Parallelism} \section{Leveraging Pipeline Parallelism} % As discussed in section \ref{background:xerces}, Xerces can be considered a complex finite-state machine % Finite-state machine belongs to the hardest application class to parallelize and process efficiently As discussed in section \ref{background:xerces}, Xerces can be considered a complex finite-state machine, the hardest type of application to parallelize and process efficiently \cite{Asanovic:EECS-2006-183}. However, \icXML{} provides logical layers between modules, which naturally enables pipeline parallel processing. However \icXML{} provides logical layers between modules, which naturally enables pipeline parallel processing. In our pipeline model, each thread is in charge of one module or one group of modules. A straight forward division is to take advantage of the layer between Parabix Subsystem and Markup Processor. In this case, the first thread $T_1$ will read 16k of XML input $I$ at a time and process all the modules in Parabix Subsystem to generates % content buffer, symbol array, URI array, context ID array and store them to a pre-allocated shared data structure $S$. content buffer, symbol array, URI array, and store them to a pre-allocated shared data structure $S$. The second thread $T_2$ consumes the data provided by the first thread and goes through all the modules in Markup Processor and writes output $O$. In the pipeline model, each thread is in charge of a group of modules. A straight forward division is to take advantage of the layer between \PS{} and \MP{}. In this case, the first thread $T_1$ reads 16k of XML input $I$ at a time and produces the content, symbol and URI streams, then stores them in a pre-allocated shared data structure $S$. The second thread $T_2$ consumes $S$, performs well-formedness and grammar-based validation then generates the output $O$. The shared data structure is implemented using a ring buffer, where each entry consists of all the arrays shared between the two threads with size of 160k. where every entry contains an independent set of data streams. In the example of Figure \ref{threads_timeline1} and \ref{threads_timeline2}, the ring buffer has four entries. A lock-free mechanism is applied to ensure that each entry can only be read or written by one thread at the same time. In Figure \ref{threads_timeline1}, the processing time of the first thread is longer, thus the second thread always wait for the first thread to finish processing one chunk of input and write to the shared memory. Figure \ref{threads_timeline2} illustrates a different situation where the second thread is slower and the first thread has to wait for the second thread finishing reading the shared data before it can reuse the memory space. In Figure \ref{threads_timeline1} the processing time of $T_1$ is longer than $T_2$; thus $T_2$ always waits for $T_1$ to write to the shared memory. Figure \ref{threads_timeline2} illustrates the scenario in which $T_1$ is faster and must wait for $T_2$ to finish reading the shared data before it can reuse the memory space. % In our pipeline model, each thread is in charge of one module or one group of modules. % A straight forward division is to take advantage of the layer between \PS{} and \MP{}. % In this case, the first thread $T_1$ will read 16k of XML input $I$ at a time % and process all the modules in \PS{} to generates % content buffer, symbol array, URI array, and store them to a pre-allocated shared data structure $S$. % The second thread $T_2$ consumes the data provided by the first thread and % goes through all the modules in Markup Processor and writes output $O$. % The shared data structure is implemented using a ring buffer, % where each entry consists of all the arrays shared between the two threads with size of 160k. % In the example of Figure \ref{threads_timeline1} and \ref{threads_timeline2}, the ring buffer has four entries. % A lock-free mechanism is applied to ensure that each entry can only be read or written by one thread at the same time. % In Figure \ref{threads_timeline1}, the processing time of the first thread is longer, % thus the second thread always wait for the first thread to finish processing one chunk of input % and write to the shared memory. % Figure \ref{threads_timeline2} illustrates a different situation where the second thread is slower % and the first thread has to wait for the second thread finishing reading the shared data before it can reuse the memory space. To understand the performance improvement that can be achieved by this pipeline model, | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.585248589515686, "perplexity": 1302.5486840455546}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027315750.62/warc/CC-MAIN-20190821022901-20190821044901-00111.warc.gz"} |
https://code.tutsplus.com/tutorials/how-to-build-a-kick-butt-css3-mega-drop-down-menu--net-15129 | Cyber Monday Sale 40% off unlimited courses & creative assets! 40% off unlimited assets! Save Now
# How to Build a Kick-Butt CSS3 Mega Drop-Down Menu
This post is part of a series called CSS3 Mastery.
Build Awesome Practical CSS3 Buttons
Often used on e-commerce or large scale websites, mega menus are becoming more and more popular, as they offer an effective solution to displaying a lot of content while keeping a clean layout. In this tutorial, we'll learn how to build a cross-browser, awesome CSS-only drop-down mega menu, using nice CSS3 features.
If you’re looking for a quick starting point, browse through our CSS Templates. Or hire a CSS3 expert. Otherwise, let's begin this tutorial.
## Step 1: Building the Navigation Bar
Let's begin with a basic menu, built with an unordered list and some basic CSS styling.
### Creating the Menu Container
We'll now apply some basic CSS styling. For the menu container, we define a fixed width that we center by setting the left and right margins to "auto".
Now, let's see how we can improve it with some CSS3 features. We need to use different syntaxes for Webkit-based browsers (like Safari) and for Mozilla-based browsers (like Firefox).
For rounded corners, the syntax will be :
For the background, we'll use gradients and a fallback color for older browsers. To keep consistency when choosing colors, there is an awesome tool called Facade that helps you find lighter and darker tones of a basic color.
The first line applies a simple background color (for older browsers); the second and third lines create a gradient from the top to the bottom using two colors : #0272a7 and #013953.
We can now add a darker border and polish the design with a "fake" inset border created with the "box-shadow" feature. The syntax is the same for all compatible browsers: the first value is the horizontal offset, the second one is the vertical offset, the third one is the blur radius (a small value makes it sharper; it will be 1 pixel in our example). We set all offsets to 0 so the blur value will create a uniform light border :
Here's the final CSS code for the #menu container :
### Styling Menu Items
We will begin with all menu items aligned to the left and space them with a margin-right (the padding will be necessary for the hover state) :
For the hover state and the drop down, I have chosen a grey color scheme for the background.
The fallback color will be a light grey (#F4F4F4) and the gradient will be applied from the top (#F4F4F4) to the bottom (#EEEEEE). Rounded corners will be applied only on top corners as we'll have the drop down sticking right under the menu items.
The left and right padding is slightly smaller here because we have a border of 1 pixel appearing on hover. If we keep the same padding, menu items will be pushed two pixels on the right because of the left and right borders added on mouse hover. To avoid that, we'll remove 1 pixel of padding on both sides, so we have 9 pixels instead of 10.
Then, we add rounded corners to the top only so the drop down will stick perfectly under the parent menu item :
Here is the final CSS for the menu items on hover :
For the links, we'll apply a nice text shadow using a simple syntax : the first and second values are horizontal and vertical offsets for the shadow (1 pixel in our example), the third one is the blur (1 pixel too) and then we have the (black) color :
Here is the final CSS for the links :
On mouse hover, as the background is grey, we'll use a darker color (#161616) for the links and the white color for the text shadow :
Finally, we need a way to indicate if there's a drop down or not by using a simple arrow image as background, it will be positioned on the right using padding and the top margin will align to it properly. On hover this top margin will be set to 7 pixels instead of 8 as we have an additional border appearing on mouse hover (otherwise, the arrow would be pushed 1 pixel down on hover) :
Here is our final code for the menu container and links; only the "home" item doesn't have any drop down content for now :
And the result is :
## Step 2: Coding the Drop Down
A "classic" drop down menu usually contains lists nested within parent list items and looks like:
### General Structure
For our Mega Menu, instead of nested lists, we'll simply use standard DIVs, which will work like any nested list :
This will be the basic structure for the drop down. The idea behind it is to be able to include any kind of content, such as paragraphs, images, custom lists or a contact form, organized into columns.
### Drop Down Containers
Containers with different sizes will hold the entire drop down content. I've chosen the tag names according to the number of columns they will contain.
To hide the drop downs, we'll use absolute positioning with a negative left margin :
The background fallback color is the same as the one used for the menu items. Modern browsers will display a gradient starting with #EEEEEE at the top (to match the parent menu item gradient) and ending with #BBBBBB at the bottom:
We'll again use rounded corners, except for the top left one :
To illustrate this, let's see how it would look if we hadn't paid attention to detail:
Now here is our example:
As you can see, the drop down sticks nicely to its parent menu item.
In order to have a perfect drop down container, we need to specify the width for each one :
And to show the drop downs on mouse hover, we'll simply use :
### Using the Drop Down Containers
Our classes are ready to be included in our menu. We'll use each one of them starting from the 5-column, layout to the single column drop down :
Here is a preview of the code above :
## Step 3: Creating the Drop Down Container Columns
Now that we have the containers ready, we'll create columns of increasing sizes, following the principles of the 960 grid system.
### Using Columns
Here is an example of a drop down containing several columns. In this example, we have different combinations using all kinds of columns :
Code preview :
## Step 4: Aligning to the Right
Now, let's see how we can align our menu and the drop down content to the right edge of the navigation bar; not only the menu item, but the drop down container should also be changed.
To accomplish this, we'll add a new class called .menu_right to the parent list item, so we reset the right margin and float it to the right :
Next, let's see the drop down. In the previous CSS code, rounded corners were applied to all corners except the left-top one to, in order to match the background of the parent menu item. Now we want this drop down to stick to the right edge of the parent menu item. So, we'll overwrite the border-radius values with a new class called .align_right, and set the top-right corner to 0.
Last but not least, we want to make the drop down appear on the right; so we'll use our new class and reset the left value, then make it stick to the right :
Now it's ready to be used in the menu :
And a small preview of the code above :
## Step 5: Adding and Styling Content
Now that we have the whole structure ready, we can add as much content as we want: text, lists, images, etc.
### General Stylings
Let's begin with some basic styling for paragraphs and headings :
We can apply a nice blue color to the links within the drop down :
### Lists Stylings
Let's revamp our lists; we have to reset some styling such as the background color or the borders which are used in the navigation bar :
### Styling Images
And to create a paragraph with an image on the left :
### Text Boxes
To highlight some content, here is an example of a dark box with rounded corners and a subtle inset shadow :
### Restylings Lists
And to finish, here's another way to style your lists using, again, some CSS3 :
## Step 6: Handling Browser Compatibility and IE6
All browsers handle hover on non-anchor tags . . . except Internet Explorer 6; so our Mega Menu is still not working with this old browser. We can fix this problem thanks to a behavior file that will add this functionality. You can find it here, and use conditional comments to target IE6 only; more explanations can be found via this article from CSS-Tricks.
To target IE6, we'll use the following code :
I've used a few PNG files in this tutorial, and, as everyone knows, IE6 doesn't support transparency so we have different solutions :
• Convert them to GIF or PNG-8 format
• Use a script
• Set a background color other than the default grey with TweakPNG for example
I'll let you choose the one that fits to your needs. Now, let's review a full working example.
## Conclusion
I hope you've enjoyed this tutorial on creating mega menus. Thanks for following along!
Also, if you need a quick starting point to building a professional website, then browse through our gallery of CSS Templates. They offer a number of ready to use, professional features. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2664584815502167, "perplexity": 1982.2663224083149}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964363189.92/warc/CC-MAIN-20211205130619-20211205160619-00402.warc.gz"} |
http://tex.stackexchange.com/questions/94247/too-many-contour-labels-in-contour-plots | # Too many contour labels in contour plots
I am trying to create a contour plot with labels in the contour lines. The data is imported from Octave, and stored in a file called data.dat. It contains many contour lines, so that manual modification of the file is not practical.
The following code reproduces the problem:
\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}
table {
0 2.875 5
3 2.875 5
0 2.825 4
3 2.825 4
0 2.75 3
3 2.75 3
0 2.5 2
3 2.5 2
0 1 1
3 1 1
};
\end{axis}
\end{tikzpicture}
\end{document}
The result has some contour lines too close to each other and therefore their labels overimpose. I would like to automatically limit the number of labels that are added to the contour lines in two ways:
1. Those labels with greater value than certain number will not appear. In my example, for example, show only labels in contour lines with value lower than 3.
2. Show labels only for selected contour lines. For example, remove the label that equals to 4.
Any hints about what options to play with are welcome, as I could not find a proper way to do this in the documentation.
-
Welcome to TeX.sx! It is better to provide a full Minimal Working Example (MWE) than a code snippet. An MWE is a complete compilable doc that includes the features necessary for the question. – Peter Jansson Jan 17 '13 at 17:26
Pgfplots currently only supports to activate all or none, and to modify the distance of adjacent labels on the same curve.
You can, however, change how such labels are to be generated using the label node code. This requires a little bit knowledge how to compare values.
A potential solution could be
\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}
contour/label node code/.code={%
% Possibility 1: use the *transformed* point meta
% (i.e. relative: 0 = smallest value, 1000=largest)
%
% -> use this to get the first 50% of the labels:
\ifdim\pgfplotspointmetatransformed pt<500pt
\node {\pgfmathprintnumber{##1}};
\else
% Possibility 2: use the *original* point meta
% -> it is in float representation.
%
% -> use this to get specific labels.
\pgfmathfloattofixed{\pgfplotspointmeta}%
%
% \ifdim works only if the |\pgfmathresult| < 16000
% and not too small.
\ifdim\pgfmathresult pt=5pt % get label "5"
\node {\pgfmathprintnumber{##1}};
\fi
\fi
},
contour prepared,
]
table {
0 2.875 5
3 2.875 5
0 2.825 4
3 2.825 4
0 2.75 3
3 2.75 3
0 2.5 2
3 2.5 2
0 1 1
3 1 1
};
\end{axis}
\end{tikzpicture}
\end{document}
I chose to use \ifdim here which expects two dimension arguments (that's why I added "pt" as suffix, that is suitable here). There are other methods to compare numeric values, but I guess this does the job here.
I always wanted to add more predefined options to control contour label placement. Perhaps I should take your question as feature request and do it eventually..
-
Thanks Christian. – user24528 Jan 21 '13 at 15:33
In fact, following your code we could easily print labels within a certain range by nesting "\ifdim" as needed. For example, to print the labels less than 4 and larger than 1 we would use \ifdim\pgfmathresult pt<4pt and then inside this if another with \ifdim\pgfmathresult pt>1pt, with the final code printing the label \node {\pgfmathprintnumber{##1}};. I think this would be a nice candidate for a predefined control option ;). – user24528 Jan 21 '13 at 16:10 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3723345696926117, "perplexity": 1406.9597414262246}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-18/segments/1461861812410.28/warc/CC-MAIN-20160428164332-00111-ip-10-239-7-51.ec2.internal.warc.gz"} |
https://webwork.maa.org/moodle/mod/forum/discuss.php?d=3014 | ## WeBWorK Problems
### Merging several matrices into one matrix
by Paul Pearson -
Number of replies: 3
Hi,
What is the best way to merge several MathObject matrices into one MathObject matrix? In particular, I would like to be able to take several m x 1 matrices (i.e., "column vectors") and merge them into an m x n matrix.
Thanks!
Paul Pearson
### Re: Merging several matrices into one matrix
by Davide Cervone -
If $C1 and $C2 are the ColumnVectors, then
$M = Matrix($C1,$C2)->transpose; would do it. But if they are really two-dimensional matrices (like columns from another matrix), then use $M = Matrix($C1->transpose,$C2->transpose)->transpose;
to get the matrix with these columns.
Hope that does it for you.
Davide
### Re: Merging several matrices into one matrix
by Paul Pearson -
Thanks Davide! That did help clarify what ought to be done.
I am using this inside a custom answer checker and noticed that when $C1->transpose was giving results with string representation like [[1,2,3]]. Since the outermost brackets in [[1,2,3]] were undesirable, I removed them using the ->row method:$Row = Matrix($C1->transpose);$Row = $Row->row(1); I put it all together into a little subroutine that takes in an array of column matrices and returns a single matrix comprised of those column matrices. Please let me know if anything in this subroutine needs improvement. ############################ sub put_cols_in_mtx { my @c = @_; my @temp = (); for my$i (0..$#c) { my$Row = Matrix($c[$i])->transpose; $Row =$Row->row(1);
push(@temp,$Row); } return Matrix(@temp)->transpose; } ############################ Thanks! Paul Pearson In reply to Paul Pearson ### Re: Merging several matrices into one matrix by Davide Cervone - It looks good. You could combine the line my$Row = Matrix($c[$i])->transpose; $Row =$Row->row(1);
into the single command
my $Row = Matrix($c[$i])->transpose->row(1); In fact, you could replace my$Row = Matrix($c[$i])->transpose; $Row =$Row->row(1);
push(@temp,$Row); with push(@temp,Matrix($c[$i])->transpose->row(1)); I guess you could also simplify the loop slightly as for my$c (@c) {
push(@temp,Matrix($c)->transpose->row(1)); } since you can iterate over your column array. Technically, you could also reuse @c by setting for my$c (@c) {$c = Matrix($c)->transpose->row(1)}
return Matrix(@c)->transpose;
rather than allocating a second array, but perhaps that is too much.
Other than that, it looks fine.
Davide | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4212457537651062, "perplexity": 8899.055405596804}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500042.8/warc/CC-MAIN-20230203024018-20230203054018-00451.warc.gz"} |
https://forum.allaboutcircuits.com/threads/mosfet-seemingly-equation-contradiction-or-my-misunderstanding.161929/ | # MOSFET - Seemingly equation contradiction (or my misunderstanding)
#### bobpease4ever
Joined Jul 28, 2019
23
Hello all,
If you remember, most textbooks say that the depletion charge in an N-MOSFET's channel in strong inversion is given by this equation:
Qb = -Sqrt( 2 * q * N_a * Epsilon_Si * 2 * Phi_F), where N_a is the substrate doping, Phi_F is the Fermi potential at the bulk.
The textbooks say that this charge is in the channel exactly when the gate voltage is equal to the threshold voltage (which itself has that charge term in it divided by C_ox). It also says this is the strong inversion charge ( so n-type carriers).
On the other hand, later on when developing the drain characteristics, it says that Q = Cox(Vgs - V_t) (with drain voltage at zero for this example). But if you look at this equation, the charge is exactly ZERO when Vgs = V_t.
How do we solve this apparent contradiction? On the one hand it says that when Vgs is equal to Vt, the charge is given as my first equation. On the other hand the charge is also ZERO when Vgs = Vt for the drain characteristics.
Could it be that even though the channel is inverted at Vgs = Vt, there is still too little charge and so they consider it as ZERO charge? But clearly there isn't zero charge when Vgs = Vt. There should be some charge there, no?
What on earth is going on here?
Thank you so much
Last edited:
#### Dodgydave
Joined Jun 22, 2012
10,591
Homework?
#### bobpease4ever
Joined Jul 28, 2019
23
#### bobpease4ever
Joined Jul 28, 2019
23
So, nobody knows?
#### pcolarusso
Joined Jul 10, 2019
1
I think Qb and Q are different things. Qb is the bulk charge so it is the charge that is there from the doping of the semiconductor. This is the charge that needs to be depleted to create the channel. Q is zero at the threshold voltage because Qb has been depleted so there is no charge there
#### bobpease4ever
Joined Jul 28, 2019
23
I think Qb and Q are different things. Qb is the bulk charge so it is the charge that is there from the doping of the semiconductor. This is the charge that needs to be depleted to create the channel. Q is zero at the threshold voltage because Qb has been depleted so there is no charge there
I have thought about that, but it still does not make sense because the threshold voltage is composed of BOTH the depletion charge voltage, AND the 2Phi_F potential, which IS the potential to invert the channel !!
I think this equation is an extreme simplification since it says that for Vgs < Vt the charge is zero.
But that is so wrong.... I am doing a calculation now to find the correct amount of charge at the channel... Let's see if it is zero or not!
Any any more input to this serious issue?
Last edited:
#### bobpease4ever
Joined Jul 28, 2019
23
I think Qb and Q are different things. Qb is the bulk charge so it is the charge that is there from the doping of the semiconductor. This is the charge that needs to be depleted to create the channel. Q is zero at the threshold voltage because Qb has been depleted so there is no charge there
I just did the calculation, and it says that the concentration of negative channel in the channel (p-channel) is exactly Nb = concentration at the bulk, when the channel reaches strong inversion. Hence there should be Nb of charge in the channel and not zero...
There is also ni^2 / Nb holes in the channel......
Makes sense because ni^2 / Nb * Nb = ni^2.
So there is charge in the channel. It's not zero charge.
#### bobpease4ever
Joined Jul 28, 2019
23
I just did the calculation, and it says that the concentration of negative channel in the channel (p-channel) is exactly Nb = concentration at the bulk, when the channel reaches strong inversion. Hence there should be Nb of charge in the channel and not zero...
There is also ni^2 / Nb holes in the channel......
Makes sense because ni^2 / Nb * Nb = ni^2.
So there is charge in the channel. It's not zero charge.
The formula is that that Qi = -Cox(Vgs - 2Phi_F - Gamma*Sqrt(2Phi_F)),
because we need Cox*Gamma*Sqrt(2PHI_F) in order to create the depletion charge, and the charge across the Cox cap is [Vgs -GammaSqrt(2PHI_F)] - 2Phi_F.
I know that PHI_S is the surface potential with respect to the bulk. But there is no potential unless we apply some at the gate(ignoring parasitics). If Vgs = 0, then the surface potential is zero. If Vgs = -Qi/Cox + Vt is calculated with Vgs = Vt, then Qi=0.
So I must conclude that this Vgs is a gate potential for any charges ABOVE the inversion charges, and NOT for the charges below threshold.
So really this equation must mean that Qi is any charge inverted AFTER strong inversion and not before. I think ........... Eureka!
Anyone could confirm this ? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.970998227596283, "perplexity": 1488.6729977420355}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764499911.86/warc/CC-MAIN-20230201045500-20230201075500-00252.warc.gz"} |
http://mail-archives.apache.org/mod_mbox/ant-ivy-user/200905.mbox/%[email protected]%3E | # ant-ivy-user mailing list archives
##### Site index · List index
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From Nicolas Lalevée <[email protected]>
Subject Re: IvyDE does not set javadoc archive path properly
Date Wed, 06 May 2009 16:17:57 GMT
```On mercredi 6 mai 2009 16:53:29 Martin Weber wrote:
> Hi all,
>
> first of all, thanks for the nice feature that downloads and sets the
> javadoc property of a resolved jar.
>
> After a resolve, the path to the javadoc archive is not set properly,
> when the path contains spaces. In my case, the path to the Ivy cache
> contains spaces, which are replaced by '%20' in the archive path filed
> on the propery page of the jar.
>
> C:\Dokumente%20und%20Einstellungen\m.weber\.ivy2\cache\org.junit\junit\java
>docs\junit-4.5.zip should be
> C:\Dokumente und Einstellungen\...
And after the %20 are replaced by spaces Eclipse show properly the javadoc ? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9496939182281494, "perplexity": 18094.414751198692}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886110578.17/warc/CC-MAIN-20170822104509-20170822124509-00290.warc.gz"} |
http://opentradingsystem.com/quantNotes/Prior_distribution_for_gamma_.html | I. Basic math.
II. Pricing and Hedging.
III. Explicit techniques.
IV. Data Analysis.
1 Time Series.
2 Classical statistics.
3 Bayesian statistics.
A. Basic idea of Bayesian analysis.
B. Estimating the mean of normal distribution with known variance.
C. Estimating unknown parameters of normal distribution.
D. Hierarchical analysis of normal model with known variance.
a. Joint posterior distribution of mean and hyperparameters.
b. Posterior distribution of mean conditionally on hyperparameters.
c. Marginal posterior distribution of hyperparameters.
i. Distribution of mu conditionally on gamma.
ii. Posterior distribution of gamma.
iii. Prior distribution for gamma.
V. Implementation tools.
VI. Basic Math II.
VII. Implementation tools II.
VIII. Bibliography
Notation. Index. Contents.
## Prior distribution for gamma.
ote, that the choice makes all the distributions proper (integrating to a finite value). Therefore, it is a sufficient and acceptable choice.
Notation. Index. Contents. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9850103855133057, "perplexity": 5296.7366321140935}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084886952.14/warc/CC-MAIN-20180117173312-20180117193312-00495.warc.gz"} |
https://miami.pure.elsevier.com/en/publications/properties-and-origins-of-the-anisotropic-eddy-induced-transport- | # Properties and origins of the anisotropic eddy-induced transport in the North Atlantic
Igor Kamenkovich, Irina I. Rypina, Pavel Berloff
Research output: Contribution to journalArticlepeer-review
18 Scopus citations
## Abstract
This study examines anisotropic transport properties of the eddying North Atlantic flow, using an idealized model of the double-gyre oceanic circulation and altimetry-derived velocities. The material transport by the time-dependent flow (quantified by the eddy diffusivity tensor) varies geographically and is anisotropic, that is, it has a well-defined direction of the maximum transport. One component of the time-dependent flow, zonally elongated large-scale transients, is particularly important for the anisotropy, as it corresponds to primarily zonal material transport and long correlation time scales. The importance of these large-scale zonal transients in the material distribution is further confirmed with simulations of idealized color dye tracers, which has implications for parameterizations of the eddy transport in non-eddy-resolving models.
Original language English (US) 778-791 14 Journal of Physical Oceanography 45 3 https://doi.org/10.1175/JPO-D-14-0164.1 Published - 2015
## Keywords
• Circulation/Dynamics
• Eddies
• Lagrangian circulation/transport
• Mesoscale processes
• Models and modeling
• Ocean circulation
• Tracers
• Oceanography | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8803986310958862, "perplexity": 12095.673200842484}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038082988.39/warc/CC-MAIN-20210415005811-20210415035811-00436.warc.gz"} |
http://en.wikipedia.org/wiki/Bell_test_experiments | # Bell test experiments
Bell test experiments or Bell's inequality experiments are designed to demonstrate the real world existence of certain theoretical consequences of the phenomenon of entanglement in quantum mechanics which could not possibly occur according to a classical picture of the world, characterised by the notion of local realism. Under local realism, correlations between outcomes of different measurements performed on separated physical systems have to satisfy certain constraints, called Bell inequalities. John Bell derived the first inequality of this kind in his paper "On the Einstein-Podolsky-Rosen Paradox".[1] Bell's Theorem states that the predictions of quantum mechanics cannot be reproduced by any local hidden variable theory.
The term "Bell inequality" can mean any one of a number of inequalities satisfied by local hidden variables theories; in practice, in present day experiments, most often the CHSH; earlier the CH74 inequality. All these inequalities, like the original inequality of Bell, by assuming local realism, place restrictions on the statistical results of experiments on sets of particles that have taken part in an interaction and then separated. A Bell test experiment is one designed to test whether or not the real world satisfies local realism.
## Conduct of optical Bell test experiments
In practice most actual experiments have used light, assumed to be emitted in the form of particle-like photons (produced by atomic cascade or spontaneous parametric down conversion), rather than the atoms that Bell originally had in mind. The property of interest is, in the best known experiments, the polarisation direction, though other properties can be used. Such experiments fall into two classes, depending on whether the analysers used have one or two output channels.
### A typical CHSH (two-channel) experiment
Scheme of a "two-channel" Bell test
The source S produces pairs of "photons", sent in opposite directions. Each photon encounters a two-channel polariser whose orientation can be set by the experimenter. Emerging signals from each channel are detected and coincidences counted by the coincidence monitor CM.
The diagram shows a typical optical experiment of the two-channel kind for which Alain Aspect set a precedent in 1982.[2] Coincidences (simultaneous detections) are recorded, the results being categorised as '++', '+−', '−+' or '−−' and corresponding counts accumulated.
Four separate subexperiments are conducted, corresponding to the four terms E(a, b) in the test statistic S (equation (2) shown below). The settings a, a′, b and b′ are generally in practice chosen to be 0, 45°, 22.5° and 67.5° respectively — the "Bell test angles" — these being the ones for which the quantum mechanical formula gives the greatest violation of the inequality.
For each selected value of a and b, the numbers of coincidences in each category (N++, N--, N+- and N-+) are recorded. The experimental estimate for E(a, b) is then calculated as:
(1) E = (N++ + N--N+-N-+)/(N++ + N-- + N+- + N-+).
Once all four E’s have been estimated, an experimental estimate of the test statistic
(2) S = E(a, b) − E(a, b′) + E(a′, b) + E(a′, b′)
can be found. If S is numerically greater than 2 it has infringed the CHSH inequality. The experiment is declared to have supported the QM prediction and ruled out all local hidden variable theories.
A strong assumption has had to be made, however, to justify use of expression (2). It has been assumed that the sample of detected pairs is representative of the pairs emitted by the source. That this assumption may not be true comprises the fair sampling loophole.
The derivation of the inequality is given in the CHSH Bell test page.
### A typical CH74 (single-channel) experiment
Setup for a "single-channel" Bell test
The source S produces pairs of "photons", sent in opposite directions. Each photon encounters a single channel (e.g. "pile of plates") polariser whose orientation can be set by the experimenter. Emerging signals are detected and coincidences counted by the coincidence monitor CM.
Prior to 1982 all actual Bell tests used "single-channel" polarisers and variations on an inequality designed for this setup. The latter is described in Clauser, Horne, Shimony and Holt's much-cited 1969 article as being the one suitable for practical use.[3] As with the CHSH test, there are four subexperiments in which each polariser takes one of two possible settings, but in addition there are other subexperiments in which one or other polariser or both are absent. Counts are taken as before and used to estimate the test statistic.
(3) S = (N(a, b) − N(a, b′) + N(a′, b) + N(a′, b′) − N(a′, ∞) − N(∞, b)) / N(∞, ∞),
where the symbol ∞ indicates absence of a polariser.
If S exceeds 0 then the experiment is declared to have infringed Bell's inequality and hence to have "refuted local realism". In order to derive (3), CHSH in their 1969 paper had to make an extra assumption, the so-called "fair sampling" assumption. This means that the probability of detection of a given photon, once it has passed the polarizer, is independent of the polarizer setting (including the 'absence' setting). If this assumption were violated, then in principle an LHV model could violate the CHSH inequality.
In a later 1974 article, Clauser and Horne replaced this assumption by a much weaker, "no enhancement" assumption, deriving a modified inequality, see the page on Clauser and Horne's 1974 Bell test.[4]
## Experimental assumptions
In addition to the theoretical assumptions made, there are practical ones. There may, for example, be a number of "accidental coincidences" in addition to those of interest. It is assumed that no bias is introduced by subtracting their estimated number before calculating S, but that this is true is not considered by some to be obvious. There may be synchronisation problems — ambiguity in recognising pairs due to the fact that in practice they will not be detected at exactly the same time.
Nevertheless, despite all these deficiencies of the actual experiments, one striking fact emerges: the results are, to a very good approximation, what quantum mechanics predicts. If imperfect experiments give us such excellent overlap with quantum predictions, most working quantum physicists would agree with John Bell in expecting that, when a perfect Bell test is done, the Bell inequalities will still be violated. This attitude has led to the emergence of a new sub-field of physics which is now known as quantum information theory. One of the main achievements of this new branch of physics is showing that violation of Bell's inequalities leads to the possibility of a secure information transfer, which utilizes the so-called quantum cryptography (involving entangled states of pairs of particles).
## Notable experiments
Over the past thirty or so years, a great number of Bell test experiments have now been conducted. These experiments are subject to assumptions, in particular the ‘no enhancement’ hypothesis of Clauser and Horne (above). The experiments are commonly interpreted to rule out local hidden variable theories, though so far no experiment has been performed which is not subject to either the locality loophole or the detection loophole. An experiment free of the locality loophole is one where for each separate measurement and in each wing of the experiment, a new setting is chosen and the measurement completed before signals could communicate the settings from one wing of the experiment to the other. An experiment free of the detection loophole is one where close to 100% of the successful measurement outcomes in one wing of the experiment are paired with a successful measurement in the other wing. This percentage is called the efficiency of the experiment. Advancements in technology have led to significant improvement in efficiencies, as well as a greater variety of methods to test the Bell Theorem. The challenge is to combine high efficiency with rapid generation of measurement settings and completion of measurements.
Some of the best known:
### Freedman and Clauser, 1972
This was the first actual Bell test, using Freedman's inequality, a variant on the CH74 inequality.[5]
### Aspect, 1981-2
Alain Aspect and his team at Orsay, Paris, conducted three Bell tests using calcium cascade sources. The first and last used the CH74 inequality. The second was the first application of the CHSH inequality. The third (and most famous) was arranged such that the choice between the two settings on each side was made during the flight of the photons (as originally suggested by John Bell).[6][7]
### Tittel and the Geneva group, 1998
The Geneva 1998 Bell test experiments showed that distance did not destroy the "entanglement". Light was sent in fibre optic cables over distances of several kilometers before it was analysed. As with almost all Bell tests since about 1985, a "parametric down-conversion" (PDC) source was used.[8][9]
### Weihs' experiment under "strict Einstein locality" conditions
In 1998 Gregor Weihs and a team at Innsbruck, led by Anton Zeilinger, conducted an ingenious experiment that closed the "locality" loophole, improving on Aspect's of 1982. The choice of detector was made using a quantum process to ensure that it was random. This test violated the CHSH inequality by over 30 standard deviations, the coincidence curves agreeing with those predicted by quantum theory.[10]
### Pan et al.'s (2000) experiment on the GHZ state
This is the first of new Bell-type experiments on more than two particles; this one uses the so-called GHZ state of three particles.[11]
### Rowe et al. (2001) are the first to close the detection loophole
The detection loophole was first closed in an experiment with two entangled trapped ions, carried out in the ion storage group of David Wineland at the National Institute of Standards and Technology in Boulder. The experiment had detection efficiencies well over 90%.[12]
### Gröblacher et al. (2007) test of Leggett-type non-local realist theories
A specific class of non-local theories suggested by Anthony Leggett is ruled out. Based on this, the authors conclude that any possible non-local hidden variable theory consistent with quantum mechanics must be highly counterintuitive.[13][14]
### Salart et al. (2008) Separation in a Bell Test
This experiment filled a loophole by providing an 18 km separation between detectors, which is sufficient to allow the completion of the quantum state measurements before any information could have traveled between the two detectors.[15][16]
### Ansmann et al. (2009) Overcoming the detection loophole in solid state
This was the first experiment testing Bell inequalities with solid-state qubits (superconducting Josephson phase qubits were used). This experiment surmounted the detection loophole using a pair of superconducting qubits in an entangled state. However, the experiment still suffered from the locality loophole because the qubits were only separated by a few millimeters.[17]
### Giustina et al. (2013) Overcoming the detection loophole for photons
The detection loophole for photons has been closed for the first time in a group by Anton Zeilinger, using highly efficient detectors. This makes photons the first system for which all of the main loopholes have been closed, albeit in different experiments. [18]
## Loopholes
Though the series of increasingly sophisticated Bell test experiments has convinced the physics community in general that local realism is untenable, it remains true that the outcome of every single experiment done so far that violates a Bell inequality can still theoretically be explained by local realism, by exploiting the detection loophole and/or the locality loophole. The locality (or communication) loophole means that since in actual practice the two detections are separated by a time-like interval, the first detection may influence the second by some kind of signal. To avoid this loophole, the experimenter has to ensure that particles travel far apart before being measured, and that the measurement process is rapid. More serious is the detection (or unfair sampling) loophole, due to the fact that particles are not always detected in both wings of the experiment. It can be imagined that the complete set of particles would behave randomly, but instruments only detect a subsample showing quantum correlations, by letting detection be dependent on a combination of local hidden variables and detector setting. Experimenters have repeatedly stated that loophole-free tests can be expected in the near future.[19] On the other hand, some researchers point out the logical possibility that quantum physics itself prevents a loophole-free test from ever being implemented.[20][21]
## References
1. ^ J.S. Bell (1964), Physics 1: 195–200
2. ^ Alain Aspect, Philippe Grangier, Gérard Roger (1982), "Experimental Realization of Einstein-Podolsky-Rosen-Bohm Gedankenexperiment: A New Violation of Bell's Inequalities", Phys. Rev. Lett. 49 (2): 91–4, Bibcode:1982PhRvL..49...91A, doi:10.1103/PhysRevLett.49.91
3. ^ J.F. Clauser, M.A. Horne, A. Shimony, R.A. Holt (1969), "Proposed experiment to test local hidden-variable theories", Phys. Rev. Lett. 23 (15): 880–4, Bibcode:1969PhRvL..23..880C, doi:10.1103/PhysRevLett.23.880
4. ^ J.F. Clauser, M.A. Horne (1974), "Experimental consequences of objective local theories", Phys. Rev. D 10 (2): 526–35, Bibcode:1974PhRvD..10..526C, doi:10.1103/PhysRevD.10.526
5. ^ S.J. Freedman, J.F. Clauser (1972), "Experimental test of local hidden-variable theories", Phys. Rev. Lett. 28 (938), Bibcode:1972PhRvL..28..938F, doi:10.1103/PhysRevLett.28.938
6. ^ Alain Aspect, Philippe Grangier, Gérard Roger (1981), "Experimental Tests of Realistic Local Theories via Bell's Theorem", Phys. Rev. Lett. 47 (7): 460–3, Bibcode:1981PhRvL..47..460A, doi:10.1103/PhysRevLett.47.460
7. ^ Alain Aspect, Jean Dalibard, Gérard Roger (1982), "Experimental Test of Bell's Inequalities Using Time-Varying Analyzers", Phys. Rev. Lett. 49 (25): 1804–7, Bibcode:1982PhRvL..49.1804A, doi:10.1103/PhysRevLett.49.1804
8. ^ W. Tittel, J. Brendel, B. Gisin, T. Herzog, H. Zbinden, N. Gisin (1998), "Experimental demonstration of quantum-correlations over more than 10 kilometers", Physical Review A 57: 3229, arXiv:quant-ph/9707042, Bibcode:1998PhRvA..57.3229T, doi:10.1103/PhysRevA.57.3229
9. ^ W. Tittel, J. Brendel, H. Zbinden, N. Gisin (1998), "Violation of Bell inequalities by photons more than 10 km apart", Physical Review Letters 81: 3563-6, arXiv:quant-ph/9806043, Bibcode:1998PhRvL..81.3563T, doi:10.1103/PhysRevLett.81.3563
10. ^ G. Weihs, T. Jennewein, C. Simon, H. Weinfurter, A. Zeilinger (1998), "Violation of Bell's inequality under strict Einstein locality conditions", Phys. Rev. Lett. 81: 5039, arXiv:quant-ph/9810080, Bibcode:1998PhRvL..81.5039W, doi:10.1103/PhysRevLett.81.5039
11. ^ Jian-Wei Pan, D. Bouwmeester, M. Daniell, H. Weinfurter & A. Zeilinger (2000). "Experimental test of quantum nonlocality in three-photon GHZ entanglement". Nature 403 (6769): 515–519. Bibcode:2000Natur.403..515P. doi:10.1038/35000514.
12. ^ M.A. Rowe, D. Kielpinski, V. Meyer, C.A. Sackett, W.M. Itano, C. Monroe, D.J. Wineland (2001), "Experimental violation of a Bell's inequality with efficient detection", Nature 409 (6822): 791–94, Bibcode:2001Natur.409..791K, doi:10.1038/35057215
13. ^ Quantum physics says goodbye to reality, physicsworld.com, 2007
14. ^ S Gröblacher, T Paterek, Rainer Kaltenbaek, S Brukner, M Zdotukowski, M Aspelmeyer, A Zeilinger (2006), "An experimental test of non-local realism", Nature 446: 871–5, arXiv:0704.2529, Bibcode:2007Natur.446..871G, doi:10.1038/nature05677, PMID 17443179
15. ^ Salart, D.; Baas, A.; van Houwelingen, J. A. W.; Gisin, N.; and Zbinden, H. (2008), "Spacelike Separation in a Bell Test Assuming Gravitationally Induced Collapses", Physical Review Letters 100 (22): 220404, arXiv:0803.2425, Bibcode:2008PhRvL.100v0404S, doi:10.1103/PhysRevLett.100.220404
16. ^ World's Largest Quantum Bell Test Spans Three Swiss Towns, phys.org, 2008-06-16
17. ^ Ansmann, Markus; H. Wang, Radoslaw C. Bialczak, Max Hofheinz, Erik Lucero, M. Neeley, A. D. O'Connell, D. Sank, M. Weides, J. Wenner, A. N. Cleland, John M. Martinis (2009-09-24). "Violation of Bell's inequality in Josephson phase qubits". Nature 461 (504-6): 2009. Bibcode:2009Natur.461..504A. doi:10.1038/nature08363.
18. ^ Giustina, Marissa; Alexandra Mech, Sven Ramelow, Bernhard Wittmann, Johannes Kofler, Jörn Beyer, Adriana Lita, Brice Calkins, Thomas Gerrits, Sae Woo Nam, Rupert Ursin & Anton Zeilinger (2013-04-14). "Bell violation using entangled photons without the fair-sampling assumption". Nature 497 (7448): 227-30. arXiv:1212.0533. Bibcode:2013Natur.497..227G. doi:10.1038/nature12012.
19. ^ R. García-Patrón, J. Fiurácek, N. J. Cerf, J. Wenger, R. Tualle-Brouri, Ph. Grangier (2004), "Proposal for a Loophole-Free Bell Test Using Homodyne Detection", Phys. Rev. Lett. 93 (13): 130409, arXiv:quant-ph/0403191, Bibcode:2004PhRvL..93m0409G, doi:10.1103/PhysRevLett.93.130409
20. ^ Richard D. Gill (2003), "Time, Finite Statistics, and Bell's Fifth Position", Foundations of Probability and Physics - 2 (Vaxjo Univ. Press): 179–206, arXiv:quant-ph/0301059, Bibcode:2003quant.ph..1059G
21. ^ Emilio Santos (2005), "Bell's theorem and the experiments: Increasing empirical support to local realism", Studies In History and Philosophy of Modern Physics 36 (3): 544–65, arXiv:quant-ph/0410193, doi:10.1016/j.shpsb.2005.05.007 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 1, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8097890019416809, "perplexity": 3274.4259415178626}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802764752.1/warc/CC-MAIN-20141217075244-00044-ip-10-231-17-201.ec2.internal.warc.gz"} |
https://mylomowalk.wordpress.com/ | # ACL 2012
What’s interesting?
A Deep Learning Tutorial by Richard Socher, Yoshua Bengio and Chris Manning.
– Selective Sharing for Multilingual Dependency Parsing. I always like the work from MIT people. This is an interesting paper on multilingual learning. The model does not assume the existing of parallel corpus, which makes it more practical. Moreover, it can transfer linguistic structures between unrelated languages.
– Unsupervised Morphology Rivals Supervised Morphology for Arabic MT. Very close to my thesis. In fact, I just need to read Mark Johnson’s 2009 paper Improving nonparameteric Bayesian inference: experiments on unsupervised word segmentation with adaptor grammars.
# One does not simply study Computational Complexity
Last night, I ran into an interesting question on Complexity while surfing the Internet. Here it is:
Let A be the language containing only the single string w where: w = 0 if God does exist and w = 1 otherwise. Is A decidable? Why or why not? (Note: the answer does not depend on your religious convictions.)
So what’s the proof. I come up with my proof that A is undecidable.
Consider a Turing Machine M used to decide A. If A is decidable, the Turing Machine M will stop and output God, the supreme being, in the output tape.
Forget about religious viewpoint, from logical point of view, let’s assume that God is the supreme being, who holds the most super power and can create anything. So, where does God come from? There must be another supreme being, who created God. The Turing Machine M, therefore continues working to output The One, who created God. But then, who created The One? Turing Machine M definitely enters infinite loop seeking for the original supreme being. Thus, A is undecidable.
Hey, does the proof sound familiar? Of course, it’s an analogue version of Turtles all the way down. In case you’ve never heard of this philosophical story, here is one of those version, found in the first page of my book Plato and a Platypus Walk into a Bar, Philogagging chapter.
Dimitri: If Atlas holds up the world, what holds up Atlas?
Tasso: Atlas stands on the back of a turtle.
Dimitri: But what does the turtle stand on?
Tasso: Another turtle.
Dimitri: And what does that turtle stand one?
Tasso: My dear Dimitri, it’s turtles all the way down!
# Recursion Theorem
(Kleene – Recursion Theorem) For any computable function
$f$ there exists an $e$ with $\phi_e = \phi_{f(e)}$.
Proof:
We define a partial recursive function $\theta$ by $\theta(u,x) = \phi_{\phi_u (u)} (x)$ . By s-m-n theorem or parameter theorem, we can find a recursive function $d$ such that
$\forall u: \phi_{d(u)}(x)=\theta(u,x)$ for $\forall x$.
Let $\phi_v = f \circ d$, choose $e=d(v)$ then we have
$\phi_e(x) = \phi_{d(v)}(x) = \theta(v,x) = \phi_{\phi_v (v)} (x) = \phi_{f \circ d(v)}(x) = \phi_{f(e)}(x)$
Using recursion theorem, we have a beautiful proof for Rice’s Theorem.
Let $C$ be a class of partial recursive functions. Set $\left\{e | \phi_e \in C \right\}$ is recursive, if and only if $C = \emptyset$ or $C$ contains all partial recursive functions.
Proof:
$C = \emptyset$ or $C = \mathbb{N}$ is trivial. We proof the case $C \ne \emptyset$ and $C \ne \mathbb{N}$.
Denote $S = \left\{e | \phi_e \in C \right\}$.
Exist $e_0 \in S$ and $e_1 \in \neg S$. If $S = \left\{e | \phi_e \in C \right\}$ is recursive, the following function is also recursive:
$f(x) = \left\{ {\begin{array}{*{20}c} {e_0 : x \in \neg S} \\ {e_1 : x \in S} \\ \end{array}} \right.$
By recursion theorem, $\exists e': \phi_e' =\phi_{f(e')}$. We consider 2 cases:
1. $e' \in S$, by index property we have $f(e') \in S$, so $e_1 \in S$ by the definition of $f$. We get contradiction.
2. $e' \in \neg S$, by index property $f(e') \in \neg S$, so $e_0 \in \neg S$ by the definition of $f$. Again we arrive to contradiction.
Functionception
Why’s recursion theorem interesting? A typical application of recursion theorem is to find a function that can print itself. Let’s say print(*program*) is that function. The output of print(*program*) is not *program* but the function that excuses print(*program*). In other words, we could ask if there is a function which can be self-conscious. I like to call it function-ception, which can be related to inception: does one know that he is dreaming in his dream?
Kleene recursion theorem offers an answer to our question: there is a function-ception, or a program that can print itself. We’ll construct such that function.
Let $\phi_e = \pi_1^2$, $\pi_i^n$ is the projection function $\pi_i^n(x_1,...,x_n) = x_i$.
By s-m-n theorem, there is total recursive function $s(e,x)$ such that $\phi_{s(e,x)}(y)=\phi_e(x,y)$. Let $g(x) = s(e,x)$. Apply Kleene recursion theorem, there is a number $n$ such that $\phi_{g(n)} = \phi_n$.
For each $x$: $\phi_n(x) = \phi_{g(n)}(x) = \phi_{s(e,n)}(x) = \phi_e(n,x) = \pi_1^2 = n$
My work here is done!
How many fixed points does a recursive function $f$ have?
Intuitively, we can see that a (total) recursive function $f$ has infinite fixed points. Recall the proof for Kleene recursion theorem, when we choose $v: \phi_v = f \circ d$. There is an infinite number of $v$ having that property. Analogically , there is an infinite number of ways to implement (write code) a function (by adding comments, using different variable names, …)
Now let’s work on some exercises using recursion theorem.
Lemma: There is a number $n \in \mathbb{N}$, such that $W_n = \left\{ n \right\}$
Proof:
We need to find a function $\phi_n$ that is only defined for input $n$ and undefined on the rest of natural numbers $\mathbb{N}-{n}$
I’m doing this in reversing way (how my thought leads me to the solution). By recursion theorem, $\exists n : \phi_n(x) = \phi_{f(n)}(x) = \phi_{s(e,n)}(x) = \phi_e(n,x)$.
Let $g(x,y)$ is the function that it is only defined for $(x,y)$ such that $x=y$. Such an $g(x,y)$ can be constructed as following:
$g(x,y) = \left\lfloor {\frac{1}{{\neg sign\left( {\left| {x - y} \right|} \right)}}} \right\rfloor$
My work here is done. There is an index $e$ such that $\phi_e(x,y) = g(x,y)$, by s-m-n theorem there is a total recursive function $s: \phi_{s(e,x)}(y) = \phi_e(x,y)$. Let $f(x) = s(e,x)$, and the last step is trivial.
Lemma: There is a number $n \in \mathbb{N}$, such that $\phi_n = \lambda x[n]$
Proof:
With the same line of proof for the previous lemma, we only need to construct a partial recursive function $g(x,y) = x \forall y$. One can easily recognize $g(x,y)$ is a projection function $\pi_1^2$
# Hello world!
I started Clojure past few days. Thanks to Jo and Milos, my nerdy classmates who are big fans of functional programing. Now I’m getting into it.
I heard of functional programming years ago, I played with Haskell but not much. Probably, the main reason I started liking Clojure because of Computational Complexity course I’ve taken at Charles University.
To be honest, I hated this course at the beginning. Machine Turing is not that bad, NP-complete and reduction techniques are pretty much fun, but recursive function and λ-calculus are so fucked up. I did hate all the lambda notations and hazy proofs with old math style.
I still hate λ-calculus if I don’t have to study for the exam. After several group studies with Jo, and he kept telling me how much he likes Scala and functional programing I thought “Hey, that’s pretty much similar to what we’re studying, you know, recursive functions and other stuff”
Yes, I like Clojure because I like λ-calculus, recursive function, partial recursive function, Kleene theorem and all other stuff. I decided to learn Clojure seriously, so I come up with an idea that I’m gonna blog about it. Of course, not only Clojure, FP but all other stuffs I like such as Computational Complexity, Machine Learning, Computational Linguistics, Lomography and so on.
Why is the blog named MyLomoWalk? I love Lomography, and Lomography is the art of coincidence. I’m a big fan of uncertainty, which often leads to coincidence. MyLomoWalk is my walk in the uncertain universe (or multiverse?) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 67, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8326036930084229, "perplexity": 875.2513015259549}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988719754.86/warc/CC-MAIN-20161020183839-00538-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://jkcs.or.kr/journal/view.php?number=4336 | J. Korean Ceram. Soc. > Volume 33(6); 1996 > Article
Journal of the Korean Ceramic Society 1996;33(6): 665.
솔-젤법에 의한 강유전성 PFN 박막의 제조 및 특성평가 류재율, 김병호, 임대순 고려대학교 재료공학과 Fabrication and Characterization of Ferroelectric PFN Thin Film by Sol-Gel Processing ABSTRACT Ferroelectric Pb(Fe1/2Nb1/2)O3 thin films were successfully fabricated on ITO/Glass substrate by sol-gel proces-sing and characterized to determine the dielectric and electric properties. Viscosity of PEN sol measured to investigate rheological properties was 3.25 cP which was proper for coating. The sol also showed Newtonian behavior. RTA(Rapid Thermal Annealing) was used for the annealing of the thin film and 1200~1700$AA$ thick PEN thin films were fabricated by repeating the intermediate and the final annealing. After the deposition of Pt as top electrode by vacuum evaporation dielectric and electric properties were measured. Dielectric properties of FFN thin film were enhanced by increasing the perovskite phase fraction with increasing the annealing temperature. Measured dielectric constant of 1700$AA$ PFN thin film annealed at $650^{circ}C$ was 890 at 1kHz Capacitatnce density and dielectric loss were 47 fF/${mu}{textrm}{m}$2 and 0.47 respectively. As a result of measuring Curie temperature PFN thin films had Curie point with a rang of 110~12$0^{circ}C$ and showed broad dielectric peak at that point. Leakage current of the PFN thin films were increased with increasing the annealing tempera-ture. Key words: Sol-gel processing, Ferroelectrics, PFN thin films, Rapid thermal annealing, Dielectric properties
TOOLS | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4895470440387726, "perplexity": 17418.051100483146}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623488534413.81/warc/CC-MAIN-20210623042426-20210623072426-00392.warc.gz"} |
http://koreascience.or.kr/article/JAKO199910102467487.page | # CERTAIN METHODS FOR PROVING TWO RESULTS CONTIGUOUS TO KUMMER'S SECOND THEOREMS
• KIM, YONGSUP (Dept. of Mathematics, Wonkwang University) ;
• RATHIE, ARJUN K. (Dept. of Mathematics, Government Dungar College (M.D.S. University)) ;
• CHOI, JUNESANG (Dept. of Mathematics, Dongguk University)
• Published : 1999.07.30
• 33 0
#### Abstract
The object of this note is to provide various methods for proving two results contiguous to Kummer's second theorem by using the classical Gauss's summation theorem and contiguous relations.
#### Keywords
Hypergeometric series;Kummer's second theorem;Gauss's summation theorem;Gauss's second summation theorem;Contiguous results;Preece's identity
#### References
1. Indian J. Math. v.34 GeneralizatioftS of Watson's theorem on the sum of a $_3F_2$ Lavoie, J.L.;Grondin, F.;Rathie, A.K.
2. Proc. London Math. Soc. v.22 no.2 The product of two generalized hypergeometric functions Preece, C.T.
3. Special Functions Rainville, E.D.
4. Rev. Mat. Estat. v.15 A short proof of Preece's identities and other contiguous results Rathie, A.K.
5. Far East J. Math. Sci. v.6 no.2 A note on an identity due to Preece Rathie, A.K.;Choi, J.
6. Le Matematiche (Catania) v.50 On Kummer's second theorem involving product of generalized hypergeometric series Rathie, A.K.;Nagar, V.
7. J. Reine Angew. Math. v.15 Uber die hypergeometrische Reihe Kummer, E.E.
8. Proc. London Math. Soc. v.28 no.2 Products of generalized hypergeometric series Bailey, W.N.
9. Generalized Hypergeometric Series Bailey, W.N.
10. Comm. Korean Math. Soc. v.13 Another proof of Kummer's second theorem Rathie, A.K.;Choi, J.
11. Comm. Korean Math. Soc. v.14 A generalization of Preece's identity Rathie, A.K.;Kim, Y. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7677385210990906, "perplexity": 20650.001328133465}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540565544.86/warc/CC-MAIN-20191216121204-20191216145204-00007.warc.gz"} |
https://link.springer.com/article/10.1007%2Fs11036-018-1000-8 | Mobile Networks and Applications
, Volume 23, Issue 4, pp 677–685
# A New Method of Cognitive Signal Recognition Based on Hybrid Information Entropy and D-S Evidence Theory
• Hui Wang
• Lili Guo
• Zheng Dou
• Yun Lin
Article
## Abstract
The automatic modulation recognition of communication signal has been widely used in many fields. However, it is very difficult to recognize the modulation in low SNR. Based on information entropy features and Dempster-Shafer evidence theory, a novel automatic modulation recognition methods is proposed in this paper. Firstly, Rényi entropy and singular entropy is used to obtain the modulation feature. Secondly, based on the normal test theory, a novel basic probability assignment function(BPAF) is presented. Finally, Dempster-Shafer evidence theory is used as a classifier. Experiment results indicate that the new approach can obtain a higher recognition result in low SNR.
## Keywords
Automatic Modulation Recognition Information Entropy Dempster-Shafer Evidence Theory Normal Test
## Notes
### Acknowledgments
This work is supported by the National Natural Science Foundation of China (61771154,61301095), the Key Development Program of Basic Research of China (JCKY2013604B001), the Fundamental Research Funds for the Central Universities (GK2080260148 and HEUCF1508).
We gratefully thank of very useful discussions of reviewers.
### Conflict of Interest
Meantime, all the authors declare that there is no conflict of interests regarding the publication of this article.
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## Authors and Affiliations
• Hui Wang
• 1
• Lili Guo
• 1
• Zheng Dou
• 1
• Yun Lin
• 1
1. 1.College of Information and Communication EngineeringHarbin Engineering UniversityHarbinChina | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8992154002189636, "perplexity": 15943.698809128166}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376827596.48/warc/CC-MAIN-20181216073608-20181216095608-00466.warc.gz"} |
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