WorldWideScience

Sample records for time forum electronic

  1. Sustainable Electronic Roadmap and Forum Summary; Sustainable Electronics Forum, October 15-18, 2012, Racine, WI

    Science.gov (United States)

    The Roadmap presents critical issues and research questions for each theme. For Theme 1, the issues for limiting the harm from materials and process in electronics industry include identifying the chemicals in products, production process, in the extraction of virgin materials, i...

  2. Summary Report about the Sustainable Materials Management (SMM) Electronics Reuse and Recycling Forum

    Science.gov (United States)

    On September 23 and 24, 2014, EPA hosted a forum to “harness the collective power of the electronics community and identify shared priorities that will advance domestic end-of-life electronics management.

  3. Discussion forum on electron beam instruments AERE Harwell

    International Nuclear Information System (INIS)

    Bainbridge, J.E.

    1980-08-01

    The purpose of this catalogue is to provide a source of information on the equipment available at AERE Harwell, to the nuclear and non-nuclear scientist. The original aim, that is, is to provide data on electron/proton beam instruments has been revised to include optical devices and ancillary preparatory equipment. The intention is to enable prospective users to have a contact who can provide further detailed information, although it must be recognised that work on certain projects completely fills the time available. This publication has been updated, first catalogue published in January 1975, to August 1980 and it is the intention that it should form part of a similar publication which incorporates details of similar equipment available throughout the UKAEA. (author)

  4. The Electronic Data Methods (EDM) forum for comparative effectiveness research (CER).

    Science.gov (United States)

    Holve, Erin; Segal, Courtney; Lopez, Marianne Hamilton; Rein, Alison; Johnson, Beth H

    2012-07-01

    AcademyHealth convened the Electronic Data Methods (EDM) Forum to collect, synthesize, and share lessons from eleven projects that are building infrastructure and using electronic clinical data for comparative effectiveness research (CER) and patient-centered outcomes research (PCOR). This paper provides a brief review of participating projects and provides a framework of common challenges. EDM Forum staff conducted a text review of relevant grant programs' funding opportunity announcements; projects' research plans; and available information on projects' websites. Additional information was obtained from presentations provided by each project; phone calls with project principal investigators, affiliated partners, and staff from the Agency for Healthcare Research and Quality (AHRQ); and six site visits. Projects participating in the EDM Forum are building infrastructure and developing innovative strategies to address a set of methodological, and data and informatics challenges, here identified in a common framework. The eleven networks represent more than 20 states and include a range of partnership models. Projects vary substantially in size, from 11,000 to more than 7.5 million individuals. Nearly all of the AHRQ priority populations and conditions are addressed. In partnership with the projects, the EDM Forum is focused on identifying and sharing lessons learned to advance the national dialogue on the use of electronic clinical data to conduct CER and PCOR. These efforts have the shared goal of addressing challenges in traditional research studies and data sources, and aim to build infrastructure and generate evidence to support a learning health care system that can improve patient outcomes.

  5. Pan-Canadian Respiratory Standards Initiative for Electronic Health Records (PRESTINE: 2011 National Forum Proceedings

    Directory of Open Access Journals (Sweden)

    M Diane Lougheed

    2012-01-01

    Full Text Available In a novel knowledge translation initiative, the Government of Ontario’s Asthma Plan of Action funded the development of an Asthma Care Map to enable adherence with the Canadian Asthma Consensus Guidelines developed under the auspices of the Canadian Thoracic Society (CTS. Following its successful evaluation within the Primary Care Asthma Pilot Project, respiratory clinicians from the Asthma Research Unit, Queen’s University (Kingston, Ontario are leading an initiative to incorporate standardized Asthma Care Map data elements into electronic health records in primary care in Ontario. Acknowledging that the issue of data standards affects all respiratory conditions, and all provinces and territories, the Government of Ontario approached the CTS Respiratory Guidelines Committee. At its meeting in September 2010, the CTS Respiratory Guidelines Committee agreed that developing and standardizing respiratory data elements for electronic health records are strategically important. In follow-up to that commitment, representatives from the CTS, the Lung Association, the Government of Ontario, the National Lung Health Framework and Canada Health Infoway came together to form a planning committee. The planning committee proposed a phased approach to inform stakeholders about the issue, and engage them in the development, implementation and evaluation of a standardized dataset. An environmental scan was completed in July 2011, which identified data definitions and standards currently available for clinical variables that are likely to be included in electronic medical records in primary care for diagnosis, management and patient education related to asthma and COPD. The scan, sponsored by the Government of Ontario, includes compliance with clinical nomenclatures such as SNOMED-CT® and LOINC®. To help launch and create momentum for this initiative, a national forum was convened on October 2 and 3, 2011, in Toronto, Ontario. The forum was designed to

  6. Auroral electron time dispersion

    International Nuclear Information System (INIS)

    Kletzing, C.A.

    1989-01-01

    A sounding rocket flight was launched from Greenland in 1985 to study high latitude, early morning auroral physics. The payload was instrumented with electron and ion detectors, AC and DC electric field experiments, a plasma density experiment, and a magnetometer to measure the ambient field. The rocket was launched during disturbed conditions, when the polar cap was in a contracted state with visible aurora overhead. The electron data contained numerous signatures indicative of time-of-flight energy dispersion characterized by a coherent structure in which lower energy electrons arrived at the rocket after higher energy electrons. A model was constructed to explain this phenomena by the sudden application of a region of parallel electric field along a length of magnetic field line above the rocket. The model incorporates detector response and uses an altitudinal density profile based on auroral zone measurements. Three types of potential structures were tried: linear, quadratic and cubic. Of the three it was found that the cubic (electric field growing in a quadratic manner moving up the field line) produced the best fit to the data. The potential region was found to be approximately 1-2 R e in extent with the lower edge 3000-4000 km away from the rocket. The background electron temperature in the model which produced the best fit to the data was of the order of 15 eV

  7. EDM forum supplement overview.

    Science.gov (United States)

    Calonge, Ned

    2012-07-01

    The Agency for Health Research and Quality funded the Electronic Data Methods Forum (EDM Forum) to share the experiences and learnings from 11 research teams funded through three different grant programs, each of which involve the use of electronic clinical data in Comparative Effectiveness Research and Patient-Centered Outcomes Research. This overview is meant to describe the context in which the EDM forum was created and to introduce the set of papers in this supplement to Medical Care that describe the challenges and approaches to the use of electronic clinical data in the three key areas of analytic methods, clinical informatics and data governance. The participants in the EDM Forum are providing innovative approaches to generate information that can support the building of a "learning health care system." The compilation of papers presented in this supplement should serve as a resource to others working to develop the infrastructure for collecting, validating and using electronic data for research.

  8. Introduction to the special issue on the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum.

    Science.gov (United States)

    Burt, Eric; Gill, Patrick

    2012-03-01

    The 8 invited and 17 contributed papers in this special issue focus on the following topical areas covered at the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum, held in San Francisco, California: 1) Materials and Resonators; 2) Oscillators, Synthesizers, and Noise; 3) Microwave Frequency Standards; 4) Sensors and Transducers; 5) Timekeeping and Time and Frequency Transfer; and 6) Optical Frequency Standards.

  9. Introduction of an Electronic Forum for Annual Development Planning (A Case Study in Banyuasin Regency, South Sumatra, Indonesia

    Directory of Open Access Journals (Sweden)

    Irwanto Irwanto

    2014-01-01

    Full Text Available Indonesian constitution was amended in 1999 and requested for local government to establish bottom up planning process that has been set as a standard approach to accommodate local aspiration in the making of annual development plan. The Musrenbang (Musyawarah Perencanaan Pembangunan/The Deliberation of development Plan was amended by Law No. 25/2004 as the stages of planning formulation process in which stakeholders and Public Administrator sit down for forum to communicate each other to find best means for local problem solution. Musrenbang need to modify since it tend to not work as become effective mechanism to accommodate aspirations of stakeholders (bottom level and hand them over to local government (upper level due to several barriers, such as; geographical distance, limited transportation system, irregular political intervention and bureaucratic red tape. Using Information Communication Technology (ICT that able to simplify the planning process by utilizing the people’s interactions expectedly can make simpler and faster procedure, including maximizing the role of Musrenbang. An Electronic forum for annual development planning will set to improve validity, effectiveness and efficiency. Banyuasin Regency, South Sumatera, Indonesia is now making preparation to introduce this system. PCM method was applied to analyze the problems for its introduction. Keywords: development plan, information communication technology, local government, musrenbang.

  10. Opportunities and challenges for comparative effectiveness research (CER) with Electronic Clinical Data: a perspective from the EDM forum.

    Science.gov (United States)

    Holve, Erin; Segal, Courtney; Hamilton Lopez, Marianne

    2012-07-01

    The Electronic Data Methods (EDM) Forum brings together perspectives from the Prospective Outcome Systems using Patient-specific Electronic data to Compare Tests and therapies (PROSPECT) studies, the Scalable Distributed Research Networks, and the Enhanced Registries projects. This paper discusses challenges faced by the research teams as part of their efforts to develop electronic clinical data (ECD) infrastructure to support comparative effectiveness research (CER). The findings reflect a set of opportunities for transdisciplinary learning, and will ideally enhance the transparency and generalizability of CER using ECD. Findings are based on 6 exploratory site visits conducted under naturalistic inquiry in the spring of 2011. Themes, challenges, and innovations were identified in the visit summaries through coding, keyword searches, and review for complex concepts. : The identified overarching challenges and emerging opportunities include: the substantial level of effort to establish and sustain data sharing partnerships; the importance of understanding the strengths and limitations of clinical informatics tools, platforms, and models that have emerged to enable research with ECD; the need for rigorous methods to assess data validity, quality, and context for multisite studies; and, emerging opportunities to achieve meaningful patient and consumer engagement and work collaboratively with multidisciplinary teams. The new infrastructure must evolve to serve a diverse set of potential users and must scale to address a range of CER or patient-centered outcomes research (PCOR) questions. To achieve this aim-to improve the quality, transparency, and reproducibility of CER and PCOR-a high level of collaboration and support is necessary to foster partnership and best practices as part of the EDM Forum.

  11. Investigating electronic word-of-mouth effects on online discussion forums: the role of perceived positive electronic word-of-mouth review credibility.

    Science.gov (United States)

    Chih, Wen-Hai; Wang, Kai-Yu; Hsu, Li-Chun; Huang, Su-Chen

    2013-09-01

    Electronic word of mouth (eWOM) has been an important factor influencing consumer purchase decisions. Using the ABC model of attitude, this study proposes a model to explain how eWOM affects online discussion forums. Specifically, we propose that platform (Web site reputation and source credibility) and customer (obtaining buying-related information and social orientation through information) factors influence purchase intentions via perceived positive eWOM review credibility, as well as product and Web site attitudes in an online community context. A total of 353 online discussion forum users in an online community (Fashion Guide) in Taiwan were recruited, and structural equation modeling (SEM) was used to test the research hypotheses. The results indicate that Web site reputation, source credibility, obtaining buying-related information, and social orientation through information positively influence perceived positive eWOM review credibility. In turn, perceived positive eWOM review credibility directly influences purchase intentions and also indirectly influences purchase intentions via product and Web site attitudes. Finally, we discuss the theoretical and managerial implications of the findings.

  12. Electronic Communities: a Forum for Supporting Women Professionals and Students in Technical and Scientific Fields

    Science.gov (United States)

    Single, Peg Boyle; Muller, Carol B.; Cunningham, Christine M.; Single, Richard M.

    In this article, we report on electronic discussion lists (e-lists) sponsored by MentorNet, the National Electronic Industrial Mentoring Network for Women in Engineering and Science. Using the Internet, the MentorNet program connects students in engineering and science with mentors working in industry. These e-lists are a feature of MentorNet's larger electronic mentoring program and were sponsored to foster the establishment of community among women engineering and science students and men and women professionals in those fields. This research supports the hypothesis that electronic communications can be used to develop community among engineering and science students and professionals and identifies factors influencing the emergence of electronic communities (e-communities). The e-lists that emerged into self-sustaining e-communities were focused on topic-based themes, such as balancing personal and work life, issues pertaining to women in engineering and science, and job searching. These e-communities were perceived to be safe places, embraced a diversity of opinions and experiences, and sanctioned personal and meaningful postings on the part of the participants. The e-communities maintained three to four simultaneous threaded discussions and were sustained by professionals who served as facilitators by seeding the e-lists with discussion topics. The e-lists were sponsored to provide women students participating in MentorNet with access to groups of technical and scientific professionals. In addition to providing benefits to the students, the e-lists also provided the professionals with opportunities to engage in peer mentoring with other, mostly female, technical and scientific professionals. We discuss the implications of our findings for developing e-communities and for serving the needs of women in technical and scientific fields.

  13. SAMJ FORUM

    African Journals Online (AJOL)

    2006-09-01

    Sep 1, 2006 ... SAMJ FORUM. 862. Undernutrition, brain growth and intellectual development ... They were matched for age and sex with a control group of 11 ... of the average weight for Cape Coloured children of this age.' Thus was the ...

  14. Forum Commentary

    Science.gov (United States)

    Kanno, Yasuko

    2014-01-01

    Social class has been underresearched in the field of applied linguistics. The central goal of this forum was to stimulate more conversation about social class as it impacts language learning and teaching. In this article, I comment on 3 salient themes that have emerged in the 5 articles: (1) agency and structure in language learning and teaching,…

  15. Drift-time measurement electronics

    International Nuclear Information System (INIS)

    Pernicka, M.

    1978-01-01

    The aim of the construction was to improve the time resolution without using the facility of time stretching, to have a fast read-out possibility, and to be still cheaper in price in comparison to other systems. A possibility was thus foreseen for using the firm Fairchild. These integrated circuits (IC) have, for example, a propagation delay of 0.75 ns for a gate. One can expect therefore less time jitter and less time difference between the different inputs. Furthermore this IC offers a greater flexibility and therefore the number of ICs decreases and distances become smaller. Working with clock frequencies up to 166.6 MHz is easily possible without running into timing problems. On the other hand, to make full use of the advantages of this IC, it was necessary to build the print as a multilayer. The only risk could be in the use of a completely new product. A further aim was to build for this system a second type of drift-time module with a short time range for measuring drift time and pulse length in rotated multiwire proportional chambers. A brief outline of the specifications of the different modules is given in table 1. (Auth.)

  16. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  17. Real time monitoring of electron processors

    International Nuclear Information System (INIS)

    Nablo, S.V.; Kneeland, D.R.; McLaughlin, W.L.

    1995-01-01

    A real time radiation monitor (RTRM) has been developed for monitoring the dose rate (current density) of electron beam processors. The system provides continuous monitoring of processor output, electron beam uniformity, and an independent measure of operating voltage or electron energy. In view of the device's ability to replace labor-intensive dosimetry in verification of machine performance on a real-time basis, its application to providing archival performance data for in-line processing is discussed. (author)

  18. Time ordering in multi-electron dynamics

    International Nuclear Information System (INIS)

    McGuire, J H; Godunov, A L; Shakov, Kh Kh; Shipakov, V A; Merabet, H; Bruch, R; Hanni, J

    2003-01-01

    Time ordering of interactions in dynamic quantum multi-electron systems provides a constraint that interconnects the time evolution of different electrons. In energy space, time ordering appears as the principal value contribution from the Green function, which corresponds to the asymptotic condition that specifies whether the system has outgoing (or possibly incoming) scattered waves. We report evidence of effects of time correlation found by comparing calculations to recent spectropolarimetric data

  19. Time ordering in multi-electron dynamics

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, J H [Department of Physics, Tulane University, New Orleans, LA (United States); Godunov, A L [Department of Physics, Tulane University, New Orleans, LA (United States); Shakov, Kh Kh [Department of Physics, Tulane University, New Orleans, LA (United States); Shipakov, V A [Troitsk Institute for Innovation and Fusion Research, Troitsk (Russian Federation); Merabet, H [Department of Physics, University of Nevada Reno, Reno, NV (United States); Bruch, R [Department of Physics, University of Nevada Reno, Reno, NV (United States); Hanni, J [Department of Physics, University of Nevada Reno, Reno, NV (United States)

    2003-01-28

    Time ordering of interactions in dynamic quantum multi-electron systems provides a constraint that interconnects the time evolution of different electrons. In energy space, time ordering appears as the principal value contribution from the Green function, which corresponds to the asymptotic condition that specifies whether the system has outgoing (or possibly incoming) scattered waves. We report evidence of effects of time correlation found by comparing calculations to recent spectropolarimetric data.

  20. The International Technical Safety Forum

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    The International Technical Safety Forum is a meeting of safety experts from several physics labs in Europe and the US. Since 1998 participants have been meeting every couple of years to discuss common challenges in safety matters. The Forum helps them define best practices and learn from the important lessons learned by others.   The Forum's participants in front of building 40. This year, the meeting took place at CERN from 12 to 16 April. “This year's meeting covered subjects ranging from communication and training in matters of safety, to cryogenic safety, emergency preparedness and risk analysis”, explains Ralf Trant, head of the CERN Safety Commission and organiser of this year’s Forum. Radiation protection issues are not discussed at the meeting since they involve different expertise. The goal of the Forum is to allow participants to share experience, learn lessons and acquire specific knowledge in a very open way. Round-table discussions, dedicated time for ...

  1. Social Relation Networks in UT-Online Community Forum

    Science.gov (United States)

    Farisi, Mohammad Imam

    2012-01-01

    So far, the existence of a virtual community forum has become a reality and social necessity in an era cybertech. It was also viewed as the electronic frontier of 21st century society that was undoubtedly for reorganizing and redefining to awareness of human being, that ways of their perceptions and explorations no longer limited by time, space,…

  2. Book of Abstracts of 18th Forum: Energy Day in Croatia: Quo Vadis- Energy in Time of Climate Change

    International Nuclear Information System (INIS)

    2009-01-01

    The 18th Forum of the Croatian Energy Society, titled Quo Vadis Energy in Times of Climate Change, is focused on analysis and thinking about energy sector development in the conditions of dramatically reducing the CO 2 and greenhouse gases emissions and in the eve of the Copenhagen Climate Summit. The commitments to radically down size CO 2 emissions will change the approach to planning and development of the energy sector. There is high probability that in the time frame of 20 to 30 years a new technology platform will have been introduced through the whole technological cycle, from generation to consumption of energy. It is expected that breakthroughs will be made towards clean and more efficient technologies, but with significantly higher price levels. The changes in the energy sector will affect everyone, from general public to energy buying companies, and most of all it will affect the companies in the energy sector. The changes in the energy sector, which are to contribute to climate preservation, are a realistic and achievable goal, but they come with a price. We can expect to see the doubling of the prices, not in the near future of course, but undoubtedly in the times of great changes in the energy sector. The realisation of these changes requires a great deal of political determination in the international context, as well as fair solutions which will enable the advancement of the underdeveloped and less developed nations. Also, a strong support to the technological development is needed. The climate preservation can be a powerful generator of the international cooperation, especially as a synergy in the technological development. Technological development can be the most important asset in solving the problems of climate preservation, with the condition, of course, that the resources for research are increased and that the developed countries join efforts in using the knowledge they have, and that a non-discriminatory transfer of knowledge to the

  3. Forum on orthophotography: Summary Report

    Science.gov (United States)

    ,

    1990-01-01

    A Forum on Orthophotography was held on May 15, 1990, at the National Aeronautics and Space Administration's Goddard Space Flight Center in Greenbelt, Maryland. The forum was sponsored jointly by the U.S. Soil Conservation Service, the U.S. Geological Survey, the National Governors' Association, and the National Association of Counties. The purpose of the forum was to expand the understanding and use of orthophoto products among the user community, as well as among those currently considering, or as yet unfamiliar with, the use of these products. It was also intended to provide a forum for assessing requirements for, and interest in, orthophoto products and for the identification and discussion of issues and future needs concerning orthophoto use and coordination. The 1-day forum was organized into three major sessions that focussed on technical aspects, user applications, and management issues. The first session presented a brief background and overview of the technical characteristics of standard and digital orthophotos. The second session included formal presentations by Federal, State, and county government agencies on their current and planned applications of orthophoto products, with particular emphasis on their use within geographic information systems. In the third session, private industry addressed their community's interest, capabilities, and potential role. This session also included a proposal by the U.S. Soil Conservation Service for a national cooperative program for the production of l:12,000-scale orthophotoquad products. In addition to the formal presentations, the forum provided a time for open discussion in which attendees had an opportunity to exchange information and make statements about their needs or other items pertinent to the production and dissemination of orthophoto products. Several agency orthophoto product exhibits and interactive demonstrations were also available throughout the day. This report includes a forum agenda and

  4. Traveling through Time: The Forum Guide to Longitudinal Data Systems. Book Four of Four: Advanced LDS Usage. NFES 2011-802

    Science.gov (United States)

    National Forum on Education Statistics, 2011

    2011-01-01

    This document is the fourth and final installment of this Forum series of guides on longitudinal data systems (LDS). One goal of the National Forum on Education Statistics (the Forum) is to improve the quality of education data gathered for use by policymakers and program decisionmakers. An approach to furthering this goal has been to pool the…

  5. Timing analysis of two-electron photoemission

    International Nuclear Information System (INIS)

    Kheifets, A S; Ivanov, I A; Bray, Igor

    2011-01-01

    We predict a significant delay of two-electron photoemission from the helium atom after absorption of an attosecond XUV pulse. We establish this delay by solving the time-dependent Schroedinger equation and by subsequently tracing the field-free evolution of the two-electron wave packet. This delay can also be related to the energy derivative of the phase of the complex double-photoionization (DPI) amplitude which we evaluate by using the convergent close-coupling method. Our observations indicate that future attosecond time delay measurements on DPI of He can provide information on the absolute quantum phase and elucidate various mechanisms of this strongly correlated ionization process. (fast track communication)

  6. Lighting detectives forum

    DEFF Research Database (Denmark)

    Bülow, Katja; Skindbjerg Kristensen, Lisbeth

    2003-01-01

    Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003.......Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003....

  7. Pengaruh Electronic Word of Mouth Pada Forum Online Female Daily Terhadap Minat Beli Produk Purbasari Di Kalangan Remaja Wanita

    OpenAIRE

    Wardani, Annisa Kesuma; ", Rumyeni

    2017-01-01

    Electronic Word of Mouth becomes a vanue or a place that is very important for consumers to give their opinions and is considered more effective than word of mouth because of the level of accessibility and wider range than traditional word of mouth offline. In communication theory using computer intermediaries or usually called Computer Mediated Communication theory examines how human behavior is maintained and changed by exchanging information through machines This study aims to find out how...

  8. Validation of foF2 and TEC Modeling During Geomagnetic Disturbed Times: Preliminary Outcomes of International Forum for Space Weather Modeling Capabilities Assessment

    Science.gov (United States)

    Shim, J. S.; Tsagouri, I.; Goncharenko, L. P.; Kuznetsova, M. M.

    2017-12-01

    To address challenges of assessment of space weather modeling capabilities, the CCMC (Community Coordinated Modeling Center) is leading the newly established "International Forum for Space Weather Modeling Capabilities Assessment." This presentation will focus on preliminary outcomes of the International Forum on validation of modeled foF2 and TEC during geomagnetic storms. We investigate the ionospheric response to 2013 Mar. geomagnetic storm event using ionosonde and GPS TEC observations in North American and European sectors. To quantify storm impacts on foF2 and TEC, we first quantify quiet-time variations of foF2 and TEC (e.g., the median and the average of the five quietest days for the 30 days during quiet conditions). It appears that the quiet time variation of foF2 and TEC are about 10% and 20-30%, respectively. Therefore, to quantify storm impact, we focus on foF2 and TEC changes during the storm main phase larger than 20% and 50%, respectively, compared to 30-day median. We find that in European sector, both foF2 and TEC response to the storm are mainly positive phase with foF2 increase of up to 100% and TEC increase of 150%. In North America sector, however, foF2 shows negative effects (up to about 50% decrease), while TEC shows positive response (the largest increase is about 200%). To assess modeling capability of reproducing the changes of foF2 and TEC due to the storm, we use various model simulations, which are obtained from empirical, physics-based, and data assimilation models. The performance of each model depends on the selected metrics, therefore, only one metrics is not enough to evaluate the models' predictive capabilities in capturing the storm impact. The performance of the model also varies with latitude and longitude.

  9. Time-Resolved Scanning Electron Microscopy

    National Research Council Canada - National Science Library

    Weber, Peter M

    2006-01-01

    .... The pulsed electron beam is obtained by rapidly switching the electron emission of a field emission tip using the AC electric field arising from exposure to the intense electromagnetic radiation...

  10. LLW Forum meeting report

    International Nuclear Information System (INIS)

    1996-01-01

    This report summarizes the Low-Level Radioactive Waste Forum (LLW Forum) meeting on May 29 through May 31, 1996.The LLW Forum is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties

  11. LLW Forum meeting report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    This report summarizes the Low-Level Radioactive Waste Forum (LLW Forum) meeting on May 29 through May 31, 1996.The LLW Forum is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties.

  12. Time-delay equation governing electron motion

    International Nuclear Information System (INIS)

    Cohn, J.

    1976-01-01

    A previously proposed differential-difference equation governing the motion of the classical radiating electron is considered further. A set of three assumptions is offered, under which the proposed equation yields asymptotically stable acceleration

  13. Existence of time-dependent density-functional theory for open electronic systems: time-dependent holographic electron density theorem.

    Science.gov (United States)

    Zheng, Xiao; Yam, ChiYung; Wang, Fan; Chen, GuanHua

    2011-08-28

    We present the time-dependent holographic electron density theorem (TD-HEDT), which lays the foundation of time-dependent density-functional theory (TDDFT) for open electronic systems. For any finite electronic system, the TD-HEDT formally establishes a one-to-one correspondence between the electron density inside any finite subsystem and the time-dependent external potential. As a result, any electronic property of an open system in principle can be determined uniquely by the electron density function inside the open region. Implications of the TD-HEDT on the practicality of TDDFT are also discussed.

  14. Carbon sequestration leadership forum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The Carbon Sequestration Leadership Forum (CSLF) is an international climate change initiative that will focus on development of carbon capture and storage technologies as a means of accomplishing long-term stabilisation of greenhouse gas levels in the atmosphere. This initiative is designed to improve these technologies through coordinated research and development with international partners and private industry. Three types of cooperation are currently envisioned within the framework of the Forum: data gathering, information exchange, and joint projects. Data gathered from participating countries will be aggregated, summarised, and distributed to all of the Forum's participants. Joint projects will be identified by member nations with the Forum serving as a mechanism for bringing together government and private sector representatives from member countries. The article also reports the inaugural meeting which was held 23-25 June 2003 in Washington.

  15. The Czechoslovak nuclear forum

    International Nuclear Information System (INIS)

    Kadlec, J.

    1992-01-01

    The Czechoslovak Nuclear Forum is a civic initiative that is involved with the safe, economically efficient and generally acceptable development of nuclear power. Its efforts are aimed at incorporation into a broader European context. The Forum is a FORATOM member organization. Its activities are intended to contribute to the establishment of a favorable climate for a further progress of nuclear power in elected bodies (Parliament, municipal and district authorities), in mass media and among the public. (M.D.)

  16. Practical guidelines for qualitative research using online forums.

    Science.gov (United States)

    Im, Eun-Ok; Chee, Wonshik

    2012-11-01

    With an increasing number of Internet research in general, the number of qualitative Internet studies has recently increased. Online forums are one of the most frequently used qualitative Internet research methods. Despite an increasing number of online forum studies, very few articles have been written to provide practical guidelines to conduct an online forum as a qualitative research method. In this article, practical guidelines in using an online forum as a qualitative research method are proposed based on three previous online forum studies. First, the three studies are concisely described. Practical guidelines are proposed based on nine idea categories related to issues in the three studies: (a) a fit with research purpose and questions, (b) logistics, (c) electronic versus conventional informed consent process, (d) structure and functionality of online forums, (e) interdisciplinary team, (f) screening methods, (g) languages, (h) data analysis methods, and (i) getting participants' feedback.

  17. Electron Waiting Times of a Cooper Pair Splitter

    Science.gov (United States)

    Walldorf, Nicklas; Padurariu, Ciprian; Jauho, Antti-Pekka; Flindt, Christian

    2018-02-01

    Electron waiting times are an important concept in the analysis of quantum transport in nanoscale conductors. Here we show that the statistics of electron waiting times can be used to characterize Cooper pair splitters that create spatially separated spin-entangled electrons. A short waiting time between electrons tunneling into different leads is associated with the fast emission of a split Cooper pair, while long waiting times are governed by the slow injection of Cooper pairs from a superconductor. Experimentally, the waiting time distributions can be measured using real-time single-electron detectors in the regime of slow tunneling, where conventional current measurements are demanding. Our work is important for understanding the fundamental transport processes in Cooper pair splitters and the predictions may be verified using current technology.

  18. Electron Waiting Times of a Cooper Pair Splitter

    DEFF Research Database (Denmark)

    Walldorf, Nicklas; Padurariu, Ciprian; Jauho, Antti-Pekka

    2018-01-01

    Electron waiting times are an important concept in the analysis of quantum transport in nanoscale conductors. Here we show that the statistics of electron waiting times can be used to characterize Cooper pair splitters that create spatially separated spin-entangled electrons. A short waiting time...... between electrons tunneling into different leads is associated with the fast emission of a split Cooper pair, while long waiting times are governed by the slow injection of Cooper pairs from a superconductor. Experimentally, the waiting time distributions can be measured using real-time single......-electron detectors in the regime of slow tunneling, where conventional current measurements are demanding. Our work is important for understanding the fundamental transport processes in Cooper pair splitters and the predictions may be verified using current technology....

  19. A direct electron detector for time-resolved MeV electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

    2017-03-01

    The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

  20. Political Games with the "Unfinished Revolution". Settling Accounts with Communism in the Times of the Civic Forum and after its Disintegration (1989-1992)

    Czech Academy of Sciences Publication Activity Database

    Suk, Jiří

    2014-01-01

    Roč. 2, č. 2 (2014), s. 101-136 ISSN 2336-3142 Institutional support: RVO:68378114 Keywords : Civic Forum * post-communism * politics Subject RIV: AB - History http://www.usd.cas.cz/casopis/czech-journal-of-contemporary-history-2-2014/

  1. Space-time evolution of electron cascades in diamond

    International Nuclear Information System (INIS)

    Ziaja, Beata; Szoeke, Abraham; Spoel, David van der; Hajdu, Janos

    2002-01-01

    The impact of a primary electron initiates a cascade of secondary electrons in solids, and these cascades play a significant role in the dynamics of ionization. Here we describe model calculations to follow the spatiotemporal evolution of secondary electron cascades in diamond. The band structure of the insulator has been explicitly incorporated into the calculations as it affects ionizations from the valence band. A Monte Carlo model was constructed to describe the path of electrons following the impact of a single electron of energy E∼250 eV. This energy is similar to the energy of an Auger electron from carbon. Two limiting cases were considered: the case in which electrons transmit energy to the lattice, and the case where no such energy transfer is permitted. The results show the evolution of the secondary electron cascades in terms of the number of electrons liberated, the spatial distribution of these electrons, and the energy distribution among the electrons as a function of time. The predicted ionization rates (∼5-13 electrons in 100 fs) lie within the limits given by experiments and phenomenological models. Calculation of the local electron density and the corresponding Debye length shows that the latter is systematically larger than the radius of the electron cloud, and it increases exponentially with the radial size of the cascade. This means that the long-range Coulomb field is not shielded within this cloud, and the electron gas generated does not represent a plasma in a single impact cascade triggered by an electron of E∼250 eV energy. This is important as it justifies the independent-electron approximation used in the model. At 1 fs, the (average) spatial distribution of secondary electrons is anisotropic with the electron cloud elongated in the direction of the primary impact. The maximal radius of the cascade is about 50 A at this time. At 10 fs the cascade has a maximal radius of ∼70 A, and is already dominated by low-energy electrons

  2. Electron dynamics in solid state via time varying wavevectors

    Science.gov (United States)

    Khaneja, Navin

    2018-06-01

    In this paper, we study electron wavepacket dynamics in electric and magnetic fields. We rigorously derive the semiclassical equations of electron dynamics in electric and magnetic fields. We do it both for free electron and electron in a periodic potential. We do this by introducing time varying wavevectors k(t). In the presence of magnetic field, our wavepacket reproduces the classical cyclotron orbits once the origin of the Schröedinger equation is correctly chosen to be center of cyclotron orbit. In the presence of both electric and magnetic fields, our equations for wavepacket dynamics differ from classical Lorentz force equations. We show that in a periodic potential, on application of electric field, the electron wave function adiabatically follows the wavefunction of a time varying Bloch wavevector k(t), with its energies suitably shifted with time. We derive the effective mass equation and discuss conduction in conductors and insulators.

  3. Water Finance Webinars and Forums

    Science.gov (United States)

    The Center hosts a series of water finance forums. These forums bring together communities with drinking water, wastewater, and stormwater project financing needs in an interactive peer-to-peer networking format.

  4. The green highway forum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    In late 2004, as part of American Coal Ash Association's (ACAA) strategic planning process, a plan was approved by its Board of Directors implementing a 'green highways' concept which emphasized use of coal combustion products (CCPs) in highways in a variety of ways including being used alone, in combination with other forms of CCPs, and combined with non ash materials. The incentives behind the developed concept were the derived advantages from beneficial technical economic and environmental impacts. Although the primary use of fly ash is concrete, other forms of CCPs could be considered for more non-traditional highway applications. For example, these might include soils stabilization, binders for in-place pavement recycling, use in flowable fills, aggregates, source materials for structural fills and embankments, components in manufactured soils, and for granular base courses beneath pavements. At this same time, unknown to ACCA, EPA Region 3 in Philadelphia was working with the Wetlands and Watershed Work Group, a non-profit organization involved in wetlands policy and management along with the Federal Highway Administration (FHWA) on their own Green Highways initiative. These groups were planning a conference, the 'Green Highway Forum'. This was held in College Park, Maryland at the University of Maryland, Nov 8-10 2005. At the conference a draft 'roadmap' was presented as a guide to executive level participants bringing the diverse viewpoints of many agencies and interest groups together. Ten guiding principals were considered. The 'Green Highways' is a new effort to recognize the 'greenness' of many projects already completed and those to be initiated. 2 photos.

  5. THE ENVIRONMENTAL COMMUNICATION FORUM

    African Journals Online (AJOL)

    could enable the more effective communication of envi:onmental issues, not forgetting the importance ... headquarters, when she explained the psychology used to try to persuade people to care for their environ- ment. ... offering a facility if those to whom it is offered are unaware of its existence, or of its value. This the forum ...

  6. 2012 National Leadership Forum

    Science.gov (United States)

    Magnuson, Peter

    2012-01-01

    Two key themes emerged from the 2012 National Leadership Forum: Taking Business to School, which was hosted by the Career and Technical Education Foundation at the end of May. The first was that employers are looking for a workforce that is technologically savvy while having leadership and employability skills. The second is that the business…

  7. EUROSAFE forum 2016

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    The proceedings of the Eurosafe forum 2016 includes contributions to the following issues: Seminar 1: nuclear installation safety - assessment; Seminar 2: Nuclear installation safety - research; Seminar 3: Waste management and decommissioning - dismantling; Seminar 4: radiation protection, environment and emergency preparedness; Seminar 5: security of nuclear installations and materials.

  8. Conceptual design for real time monitoring of electron microbeam

    International Nuclear Information System (INIS)

    Kim, Ji Seok; Kim, Hyun Ki; Jang, Mee; Choi, Chang Woon; Sun, Gwang Min; Lee, Jai Ki

    2008-01-01

    It is recognized that the microbeam is powerful system to understand the interaction of ionizing radiation with cells. Especially, electron microbeam system is useful to investigate the effect of low-LET radiation for cells. Electron microbeam has been developed in KIRAMS. It can irradiate the small volume in cell level by collimator and electromagnetic field and give local dose to individual cell by controlling the number of electrons. When the electron microbeam irradiates the individual cell, however, there is a possibility to change the current and intended trajectory of electron beam. Because this possibility introduces the uncertainty of dose, it is necessary to monitor the trajectory and current of electron beam. This study deals with development of real time monitoring device to confirm beam quality and to control if necessary during experiment. Consequently we designed dual monitoring device to solve various factors. And we optimize the design by simulation. (author)

  9. Universal relaxation times for electron and nucleon gases

    OpenAIRE

    Pelc, M.; Marciak-Kozlowska, J.; Kozlowski, M.

    2007-01-01

    In this paper we calculate the universal relaxation times for electron and nucleon fermionic gases. We argue that the universal relaxation time tau(i) is equal tau(i)=h/m square v(i) where v(i)=alpha(i)c and alpha(1)=0.15 for nucleon gas and alpha(2)=1/137 for electron gas, c=light velocity. With the universal relaxation time we formulate the thermal Proca equation for fermionic gases. Key words: universal relaxation time, thermal universal Proca equation.

  10. Excess electrons in simple fluids. IV. Real time behavior

    International Nuclear Information System (INIS)

    Nichols, A.L. III; Chandler, D.

    1987-01-01

    The polaron theory for an excess electron in liquids due to Chandler et al. [J. Chem. Phys. 81, 1975 (1984)] is extended to the real time domain by the method of analytic continuation. For the case of an adiabatic solvent, the theory predicts that the electron momentum correlations relax nonexponentially in time, and that this long time tail contributes to a diminuation of the electron mobility. However, for short ranged forces, a mean-field approximation employed in this application of the polaron theory leads to a decay that is one power of t -1 higher than the generally accepted result for the quantum Lorenz gas. Along with this analytical analysis, we present numerical solutions of the analytically continued equations for the case of an adiabatic hard sphere solvent. We find that at low solvent densities, the electronic states are relatively diffuse, and the absorption spectra is maximum at the zero frequency diffusive mode. In this density regime, the electron mobility is a decreasing function of temperature. At higher densities, the electron mobility drops precipitously and the spectra has its maxima at a nonzero frequency. Here, the mobility is an increasing function of temperature. Corresponding behaviors of the electron mean-square displacement correlation function are discussed. The high density behaviors are the dynamical consequences of ground state dominance or self-trapping where diffusion requires excitation to high energy extended states. These results augment our earlier work on the equilibrium or thermodynamic consequences of this theory

  11. Internet Forums for Suicide Bereavement.

    Science.gov (United States)

    Bailey, Eleanor; Krysinska, Karolina; O'Dea, Bridianne; Robinson, Jo

    2017-11-01

    Bereavement by suicide is associated with a number of consequences including poor mental health outcomes and increased suicide risk. Despite this, the bereaved by suicide may be reluctant to seek help from friends, family, and professionals. Internet forums and social networking sites are a popular avenue of support for the bereaved, but to date there is a lack of research into their use and efficacy. To survey users of suicide bereavement Internet forums and Facebook groups regarding their help-seeking behaviors, use of forums, and perceived benefits and limitations of such use. This study employed a cross-sectional design in which users of suicide bereavement Internet forums and Facebook groups completed an anonymous online survey. Participants were 222 users of suicide bereavement Internet forums. Most participants (93.2%) had sought face-to-face help from sources other than Internet forums, but were more likely to seek help in the near future from informal rather than formal sources. Forums were perceived as highly beneficial and there were few limitations. The generalizability of these results to other internet forums may be limited. Additionally, we were not able to examine differences between forums in terms of quality or user-reported efficacy. Finally, the data reflects the subjective views of forum users, which may differ from the views of moderators or experts. Internet forums, including Facebook groups, appear to be a useful adjunct to face-to-face help-seeking for supporting those who have been bereaved by suicide.

  12. Impact of Electronic Signatures and Time Stamping for the Protection of Electronic Agreements

    Directory of Open Access Journals (Sweden)

    Tadas Limba

    2012-12-01

    Full Text Available The article e495 valuates the impact of e-signatures and time stamping on electronic contracts and electronic documents for performing e-business opportunities and goals, and analyses e-signature application for business cases. Various electronic services, virtual shopping, electronic cash transactions are becoming increasingly popular as they allow users to quickly perform different actions, operations and functions. It is important not only for convenience, but also to ensure consumer data security and reliability. Security reasons are not enough for security transmitted data, since this method does not allow clarification of information about sender identity.Use of electronic signatures, electronic identities, checgs and ensures a very high level of data security in interchange data processes. E-signature allows e-business companies to transfer the company’s operation business processes and their application to the organization and management in the electronic environment, also automate internal and external compans processes, includinggon-going business processes.The object of paper is .-signature and time stamping application in the theoretical and practical way.The goal of this paper while evaluating and estimating the .-signature and time stamping application, i’s regulation and legal implementation worldwidesand in Lithuania—is to provideluseful recommendations for more efficient impact developing -commerce and -business in situations when -signature and time stamping is used for ensuring electronic contracs security.

  13. Impact of Electronic Signatures and Time Stamping for the Protection of Electronic Agreements

    Directory of Open Access Journals (Sweden)

    Tadas Limba

    2013-02-01

    Full Text Available The article e495 valuates the impact of e-signatures and time stamping on electronic contracts and electronic documents for performing e-business opportunities and goals, and analyses e-signature application for business cases. Various electronic services, virtual shopping, electronic cash transactions are becoming increasingly popular as they allow users to quickly perform different actions, operations and functions. It is important not only for convenience, but also to ensure consumer data security and reliability. Security reasons are not enough for security transmitted data, since this method does not allow clarification of information about sender identity. Use of electronic signatures, electronic identities, checgs and ensures a very high level of data security in interchange data processes. E-signature allows e-business companies to transfer the company’s operation business processes and their application to the organization and management in the electronic environment, also automate internal and external compans processes, includinggon-going business processes. The object of paper is .-signature and time stamping application in the theoretical and practical way. The goal of this paper while evaluating and estimating the .-signature and time stamping application, i’s regulation and legal implementation worldwidesand in Lithuania—is to provideluseful recommendations for more efficient impact developing -commerce and -business in situations when -signature and time stamping is used for ensuring electronic contracs security.

  14. Radiation protection forum

    International Nuclear Information System (INIS)

    Cabral, W.

    2010-01-01

    The National Director of the Nuclear Regulatory Authority and Radiation Protection of Uruguay in the first forum for radiation protection set out the following themes: activity of regulatory body, radiation safety, physical security, safeguards, legal framework, committed substantive program, use of radiation, risks and benefits, major sources of radiation, the national regulatory framework, national inventory of sources, inspections, licensing, import and export of sources control , radioactive transport, materials safety, agreements, information and teaching, radiological emergencies and prompt response.

  15. Young physicists' forum

    International Nuclear Information System (INIS)

    Adams, T.

    2001-01-01

    The Young Physicists' Forum was an opportunity for the younger members of the particle-physics community to gather at Snowmass 2001 and to study and debate major issues that face the field over the next twenty years. Discussions were organized around three major topics: outreach and education, the impact of globalization, and building a robust and balanced field. We report on the results of these discussions, as presented on July 17, 2001

  16. Extreme localization of electrons in space and time.

    Science.gov (United States)

    Hommelhoff, Peter; Kealhofer, Catherine; Aghajani-Talesh, Anoush; Sortais, Yvan R P; Foreman, Seth M; Kasevich, Mark A

    2009-04-01

    Electron emission from sharp metal tips can take place on sub-femtosecond time scales if the emission is driven by few cycle femtosecond laser pulses. Here we outline the experimental prerequisites in detail, discuss emission regimes and relate them to recent experiments in the gas phase (attosecond physics). We present a process that leads to single atom tip emitters that are stable under laser illumination and conclude with a discussion of how to achieve short electron pulses at a target.

  17. Time development of a blast wave with shock heated electrons

    International Nuclear Information System (INIS)

    Edgar, R.J.; Cox, D.P.

    1983-01-01

    Accurate approximations are presented for the time development of both edge conditions and internal structures of a blast wave with shock heated electrons, and equal ion and electron temperatures at the shock. The cases considered evolve in cavities with power law ambient densities (including the uniform ambient density case) and have negligible external pressure. Account is taken of possible saturation of the thermal conduction flux. The structures evolve smoothly to the adiabatic structures

  18. Distribution of tunnelling times for quantum electron transport

    International Nuclear Information System (INIS)

    Rudge, Samuel L.; Kosov, Daniel S.

    2016-01-01

    In electron transport, the tunnelling time is the time taken for an electron to tunnel out of a system after it has tunnelled in. We define the tunnelling time distribution for quantum processes in a dissipative environment and develop a practical approach for calculating it, where the environment is described by the general Markovian master equation. We illustrate the theory by using the rate equation to compute the tunnelling time distribution for electron transport through a molecular junction. The tunnelling time distribution is exponential, which indicates that Markovian quantum tunnelling is a Poissonian statistical process. The tunnelling time distribution is used not only to study the quantum statistics of tunnelling along the average electric current but also to analyse extreme quantum events where an electron jumps against the applied voltage bias. The average tunnelling time shows distinctly different temperature dependence for p- and n-type molecular junctions and therefore provides a sensitive tool to probe the alignment of molecular orbitals relative to the electrode Fermi energy.

  19. Frontend electronics for high-precision single photo-electron timing using FPGA-TDCs

    Energy Technology Data Exchange (ETDEWEB)

    Cardinali, M., E-mail: cardinal@kph.uni-mainz.de [Institut für Kernphysik, Johannes Gutenberg-University Mainz, Mainz (Germany); Helmholtz Institut Mainz, Mainz (Germany); Dzyhgadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Ugur, C.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V.Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others

    2014-12-01

    The next generation of high-luminosity experiments requires excellent particle identification detectors which calls for Imaging Cherenkov counters with fast electronics to cope with the expected hit rates. A Barrel DIRC will be used in the central region of the Target Spectrometer of the planned PANDA experiment at FAIR. A single photo-electron timing resolution of better than 100 ps is required by the Barrel DIRC to disentangle the complicated patterns created on the image plane. R and D studies have been performed to provide a design based on the TRB3 readout using FPGA-TDCs with a precision better than 20 ps RMS and custom frontend electronics with high-bandwidth pre-amplifiers and fast discriminators. The discriminators also provide time-over-threshold information thus enabling walk corrections to improve the timing resolution. Two types of frontend electronics cards optimised for reading out 64-channel PHOTONIS Planacon MCP-PMTs were tested: one based on the NINO ASIC and the other, called PADIWA, on FPGA discriminators. Promising results were obtained in a full characterisation using a fast laser setup and in a test experiment at MAMI, Mainz, with a small scale DIRC prototype. - Highlights: • Frontend electronics for Cherenkov detectors have been developed. • FPGA-TDCs have been used for high precision timing. • Time over threshold has been utilised for walk correction. • Single photo-electron timing resolution less than 100 ps has been achieved.

  20. Confinement time exceeding one second for a toroidal electron plasma.

    Science.gov (United States)

    Marler, J P; Stoneking, M R

    2008-04-18

    Nearly steady-state electron plasmas are trapped in a toroidal magnetic field for the first time. We report the first results from a new toroidal electron plasma experiment, the Lawrence Non-neutral Torus II, in which electron densities on the order of 10(7) cm(-3) are trapped in a 270-degree toroidal arc (670 G toroidal magnetic field) by application of trapping potentials to segments of a conducting shell. The total charge inferred from measurements of the frequency of the m=1 diocotron mode is observed to decay on a 3 s time scale, a time scale that approaches the predicted limit due to magnetic pumping transport. Three seconds represents approximately equal to 10(5) periods of the lowest frequency plasma mode, indicating that nearly steady-state conditions are achieved.

  1. Development of real-time low energy electron calorimeter

    International Nuclear Information System (INIS)

    Noriah Mod Ali; Smith, F.A.

    1999-01-01

    A low energy electron beam calorimeter with a thin film window has been fabricated to facilitate a reliable method of dose assessment for electron beam energies down to 200 keV. The system was designed to incorporate a data-logger in order that it could be used on the self-shielded 200 keV facility at MINT. In use, the calorimeter started logging temperature a short time before it passed under the beam and it continued taking data until well after the end of the irradiation. Data could be retrieved at any time after the calorimeter had emerged from the irradiator

  2. Visual Analysis of MOOC Forums with iForum.

    Science.gov (United States)

    Fu, Siwei; Zhao, Jian; Cui, Weiwei; Qu, Huamin

    2017-01-01

    Discussion forums of Massive Open Online Courses (MOOC) provide great opportunities for students to interact with instructional staff as well as other students. Exploration of MOOC forum data can offer valuable insights for these staff to enhance the course and prepare the next release. However, it is challenging due to the large, complicated, and heterogeneous nature of relevant datasets, which contain multiple dynamically interacting objects such as users, posts, and threads, each one including multiple attributes. In this paper, we present a design study for developing an interactive visual analytics system, called iForum, that allows for effectively discovering and understanding temporal patterns in MOOC forums. The design study was conducted with three domain experts in an iterative manner over one year, including a MOOC instructor and two official teaching assistants. iForum offers a set of novel visualization designs for presenting the three interleaving aspects of MOOC forums (i.e., posts, users, and threads) at three different scales. To demonstrate the effectiveness and usefulness of iForum, we describe a case study involving field experts, in which they use iForum to investigate real MOOC forum data for a course on JAVA programming.

  3. Time resolved electron microscopy for in situ experiments

    International Nuclear Information System (INIS)

    Campbell, Geoffrey H.; McKeown, Joseph T.; Santala, Melissa K.

    2014-01-01

    Transmission electron microscopy has functioned for decades as a platform for in situ observation of materials and processes with high spatial resolution. Yet, the dynamics often remain elusive, as they unfold too fast to discern at these small spatial scales under traditional imaging conditions. Simply shortening the exposure time in hopes of capturing the action has limitations, as the number of electrons will eventually be reduced to the point where noise overtakes the signal in the image. Pulsed electron sources with high instantaneous current have successfully shortened exposure times (thus increasing the temporal resolution) by about six orders of magnitude over conventional sources while providing the necessary signal-to-noise ratio for dynamic imaging. We describe here the development of this new class of microscope and the principles of its operation, with examples of its application to problems in materials science

  4. Time resolved electron microscopy for in situ experiments

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Geoffrey H., E-mail: ghcampbell@llnl.gov; McKeown, Joseph T.; Santala, Melissa K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-12-15

    Transmission electron microscopy has functioned for decades as a platform for in situ observation of materials and processes with high spatial resolution. Yet, the dynamics often remain elusive, as they unfold too fast to discern at these small spatial scales under traditional imaging conditions. Simply shortening the exposure time in hopes of capturing the action has limitations, as the number of electrons will eventually be reduced to the point where noise overtakes the signal in the image. Pulsed electron sources with high instantaneous current have successfully shortened exposure times (thus increasing the temporal resolution) by about six orders of magnitude over conventional sources while providing the necessary signal-to-noise ratio for dynamic imaging. We describe here the development of this new class of microscope and the principles of its operation, with examples of its application to problems in materials science.

  5. Examining Electron-Boson Coupling Using Time-Resolved Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sentef, Michael; Kemper, Alexander F.; Moritz, Brian; Freericks, James K.; Shen, Zhi-Xun; Devereaux, Thomas P.

    2013-12-26

    Nonequilibrium pump-probe time-domain spectroscopies can become an important tool to disentangle degrees of freedom whose coupling leads to broad structures in the frequency domain. Here, using the time-resolved solution of a model photoexcited electron-phonon system, we show that the relaxational dynamics are directly governed by the equilibrium self-energy so that the phonon frequency sets a window for “slow” versus “fast” recovery. The overall temporal structure of this relaxation spectroscopy allows for a reliable and quantitative extraction of the electron-phonon coupling strength without requiring an effective temperature model or making strong assumptions about the underlying bare electronic band dispersion.

  6. Pandemic influenza communication: views from a deliberative forum.

    Science.gov (United States)

    Rogers, Wendy A; Street, Jackie M; Braunack-Mayer, Annette J; Hiller, Janet E

    2009-09-01

    To use a deliberative forum to elicit community perspectives on communication about pandemic influenza planning, and to compare these findings with the current Australian national communication strategy. Deliberative forum of 12 persons randomly selected from urban South Australia. Forum members were briefed by experts in infection control, virology, ethics and public policy before deliberating on four key questions: what, how and when should the community be told about pandemic influenza and by whom? The forum recommended provision of detailed and comprehensive information by credible experts, rather than politicians, using a variety of media including television and internet. Recommendations included cumulative communication to build expertise in the community, and specific strategies to include groups such as young people, people with physical or mental disabilities, and rural and remote communities. Information provided should be practical, accurate, and timely, with no 'holding back' about the seriousness of a pandemic. The forum expressed confidence in the expert witnesses, despite the acknowledged uncertainty of many of the predictions. The deliberative forum's recommendations were largely consistent with the Australian national pandemic influenza communication strategy and the relevant literature. However, the forum recommended: release of more detailed information than currently proposed in the national strategy; use of non-political spokespersons; and use of novel communication methods. Their acceptance of uncertainty suggests that policy makers should be open about the limits of knowledge in potentially threatening situations. Our findings show that deliberative forums can provide community perspectives on topics such as communication about pandemic influenza.

  7. Time Resolved Broadband Terahertz Relaxation Dynamics of Electron in Water

    DEFF Research Database (Denmark)

    Wang, Tianwu; Iwaszczuk, Krzysztof; Cooke, David G.

    We investigated the transient response of the solvated electron in water ejected by photodetachment from potassium ferrocyanide using time resolved terahertz spectroscopy (TSTS). Ultrabroadband THz transients are generated and detected by a two-color femtosecond-induced air plasma and air biased...

  8. LLW Forum meeting report

    International Nuclear Information System (INIS)

    1991-01-01

    This document reports the details of the Quarterly Meeting of the Low- Level Radioactive Waste Forum held in San Diego, California during January 23-25, 1991. Topics discussed include: State and Compact Progress Reports; Legal Updates; Update on Technical Assistance; Advanced Notice of Proposed Rulemaking Regarding Surcharge Rebates; Update on TCC Activities; NRC Update; Disposal of Commercial Mixed Waste; Update on EPA Activities; ACNW Working Group on Mixed Waste; National Profile on Mixed Waste; Commercial Perspective on Mixed Waste; Update on DOT Activities; Source Terms; Materials and Waste; Storage: and Waste Acceptance Criteria and Packaging

  9. A real-time low energy electron calorimeter

    International Nuclear Information System (INIS)

    Mod Ali, N.; Smith, F.A.

    1999-01-01

    A real-time low energy electron calorimeter with a thin film window has been designed and fabricated to facilitate a reliable method of dose assessment for electron beam energies down to 200 keV. The work was initiated by the Radiation Physics Group of Queen Mary and Westfield College in collaboration with the National Physical Laboratory (NPL), Teddington. Irradiations were performed on the low and medium electron energy electron accelerators at the Malaysian Institute for Nuclear Technology Research (MINT). Calorimeter response was initially tested using the on-line temperature measurements for a 500-keV electron beam. The system was later redesigned by incorporating a data-logger to use on the self-shielded 200-keV beam. In use, the final version of the calorimeter could start logging temperature a short time before the calorimeter passed under the beam and continue measurements throughout the irradiation. Data could be easily retrieved at the end of the exposure. (author)

  10. Time-dependent aspects of electron degradation: 4, Subexcitation electrons in nitrogen and carbon dioxide

    International Nuclear Information System (INIS)

    Kimura, Mineo; Inokuti, Mitio; Kowari, Ken-ichi; Dillon, M.A.; Pagnamenta, A.

    1988-01-01

    We discuss here the temporal behavior of subexcitation electrons and the yields of products due to these subexcitation electrons. Our examples concern cases in which resonance scattering of electrons occurs, such as vibrational and rotational excitation in N 2 and negative-ion formation in CO 2 . One focus of the present work is a test of the continuous-slowing-down-approximation (CSDA) which we compare to the full solution of the time-dependent Spencer-Fano theory, which has been developed recently. 11 refs., 6 figs., 1 tab

  11. Time dependence of microsecond intense electron beam transport in gases

    International Nuclear Information System (INIS)

    Lucey, R.F. Jr.; Gilgenback, R.M.; Tucker, J.E.; Brake, M.L.; Enloe, C.L.; Repetti, T.E.

    1987-01-01

    The authors present results of long-pulse (0.5 μs) electron beam propagation in the ion focused regime (IFR). Electron beam parameters are 800 kV with several hundred amperes injected current. For injection into air (from 0.7 mTorr to 75 mTorr) and helium (from 14 mTorr to 227 mTorr) the authors observe a ''time-dependent propagation window'' in which efficient (up to 100%) propagation starts at a time comparable to the electron impact ionization time needed to achieve n/sub i/ -- (1/γ/sup 2/)n/sub eb/. The transport goes abruptly to zero about 50-150 ns after this initial propagation. This is followed by erratic propagation often consisting of numerous narrower pulses 10-40 ns wide. In these pulses the transported current can be 100% of the injected current, but is generally lower. As the fill pressure is increased, there are differences in the propagated beam pulse, which can be summarized as follows: 1) the temporal occurrence of the beam propagation window shifts to earlier times, 2) the propagated beam current has much faster risetimes, 3) a larger portion of the injected beam is propagated. Similar results are observed when the electron beam is propagated in helium. However, at a given pressure, the beam transport window occurs at later times and exhibits a slower risetime. These effects are consistent with electron beam-induced ionization. Experiments are being performed to determine if the observed beam instability is due to the ion hose instability or streaming instability

  12. Measuring the electron bunch timing with femtosecond resolution at FLASH

    International Nuclear Information System (INIS)

    Bock, Marie Kristin

    2013-03-01

    Bunch arrival time monitors (BAMs) are an integral part of the laser-based synchronisation system which is being developed at the Free Electron Laser in Hamburg (FLASH).The operation principle comprises the measurement of the electron bunch arrival time relative to the optical timing reference, which is provided by actively length-stabilised fibre-links of the synchronisation system. The monitors are foreseen to be used as a standard diagnostic tool, not only for FLASH but also for the future European X-Ray Free-Electron Laser (European XFEL). The present bunch arrival time monitors have evolved from proof-of-principle experiments to beneficial diagnostic devices, which are almost permanently available during standard machine operation. This achievement has been a major objective of this thesis. The developments went in parallel to improvements in the reliable and low-maintenance operation of the optical synchronisation system. The key topics of this thesis comprised the characterisation and optimisation of the opto-mechanical front-ends of both, the fibre-links and the BAMs. The extent of applications involving the bunch arrival time information has been enlarged, providing automated measurements for properties of the RF acceleration modules, for instance, the RF on-crest phase determination and the measurement of energy fluctuations. Furthermore, two of the currently installed BAMs are implemented in an active phase and gradient stabilisation of specific modules in order to minimise the arrival time jitter of the electron bunches at the location of the FEL undulators, which is crucial for a high timing resolution of pump-probe experiments.

  13. Measuring the electron bunch timing with femtosecond resolution at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Marie Kristin

    2013-03-15

    Bunch arrival time monitors (BAMs) are an integral part of the laser-based synchronisation system which is being developed at the Free Electron Laser in Hamburg (FLASH).The operation principle comprises the measurement of the electron bunch arrival time relative to the optical timing reference, which is provided by actively length-stabilised fibre-links of the synchronisation system. The monitors are foreseen to be used as a standard diagnostic tool, not only for FLASH but also for the future European X-Ray Free-Electron Laser (European XFEL). The present bunch arrival time monitors have evolved from proof-of-principle experiments to beneficial diagnostic devices, which are almost permanently available during standard machine operation. This achievement has been a major objective of this thesis. The developments went in parallel to improvements in the reliable and low-maintenance operation of the optical synchronisation system. The key topics of this thesis comprised the characterisation and optimisation of the opto-mechanical front-ends of both, the fibre-links and the BAMs. The extent of applications involving the bunch arrival time information has been enlarged, providing automated measurements for properties of the RF acceleration modules, for instance, the RF on-crest phase determination and the measurement of energy fluctuations. Furthermore, two of the currently installed BAMs are implemented in an active phase and gradient stabilisation of specific modules in order to minimise the arrival time jitter of the electron bunches at the location of the FEL undulators, which is crucial for a high timing resolution of pump-probe experiments.

  14. Forum-ing: Signature practice for public theological discourse ...

    African Journals Online (AJOL)

    The forum meets every Monday morning, except when there is a national holiday. It has operated 30 consecutive years. The forum has a series of presentations, including the opening prayer, self-introductions of each person, a report of the executive director, special presentations from selected community groups, reports, ...

  15. Real-time electron-beam dose monitoring

    International Nuclear Information System (INIS)

    McKeown, J.

    1995-01-01

    A new technique to monitor the integrated dose that a product receives in an irradiation facility is determined by collecting the charge that passes through the product. The technique allows the absorbed dose to be monitored as the irradiation is taking place, i.e. on-line and in real time. The procedure will also provide a means of directly measuring the electron energy, independent of the accelerator control system. The irradiation plant operator can immediately detect a problem of inadequate electron energy and take appropriate action. Examples taken on the IMPELA trademark accelerator at the Iotron Irradiation Facility in Vancouver are presented

  16. Electron Bunch Timing with Femtosecond Precision in a Superconducting Free-Electron Laser

    Science.gov (United States)

    Löhl, F.; Arsov, V.; Felber, M.; Hacker, K.; Jalmuzna, W.; Lorbeer, B.; Ludwig, F.; Matthiesen, K.-H.; Schlarb, H.; Schmidt, B.; Schmüser, P.; Schulz, S.; Szewinski, J.; Winter, A.; Zemella, J.

    2010-04-01

    High-gain free-electron lasers (FELs) are capable of generating femtosecond x-ray pulses with peak brilliances many orders of magnitude higher than at other existing x-ray sources. In order to fully exploit the opportunities offered by these femtosecond light pulses in time-resolved experiments, an unprecedented synchronization accuracy is required. In this Letter, we distributed the pulse train of a mode-locked fiber laser with femtosecond stability to different locations in the linear accelerator of the soft x-ray FEL FLASH. A novel electro-optic detection scheme was applied to measure the electron bunch arrival time with an as yet unrivaled precision of 6 fs (rms). With two beam-based feedback systems we succeeded in stabilizing both the arrival time and the electron bunch compression process within two magnetic chicanes, yielding a significant reduction of the FEL pulse energy jitter.

  17. Electron Bunch Timing with Femtosecond Precision in a Superconducting Free-Electron Laser

    International Nuclear Information System (INIS)

    Loehl, F.; Arsov, V.; Felber, M.; Hacker, K.; Lorbeer, B.; Ludwig, F.; Matthiesen, K.-H.; Schlarb, H.; Schmidt, B.; Winter, A.; Jalmuzna, W.; Schmueser, P.; Schulz, S.; Zemella, J.; Szewinski, J.

    2010-01-01

    High-gain free-electron lasers (FELs) are capable of generating femtosecond x-ray pulses with peak brilliances many orders of magnitude higher than at other existing x-ray sources. In order to fully exploit the opportunities offered by these femtosecond light pulses in time-resolved experiments, an unprecedented synchronization accuracy is required. In this Letter, we distributed the pulse train of a mode-locked fiber laser with femtosecond stability to different locations in the linear accelerator of the soft x-ray FEL FLASH. A novel electro-optic detection scheme was applied to measure the electron bunch arrival time with an as yet unrivaled precision of 6 fs (rms). With two beam-based feedback systems we succeeded in stabilizing both the arrival time and the electron bunch compression process within two magnetic chicanes, yielding a significant reduction of the FEL pulse energy jitter.

  18. Development of an electron momentum spectrometer for time-resolved experiments employing nanosecond pulsed electron beam

    Science.gov (United States)

    Tang, Yaguo; Shan, Xu; Liu, Zhaohui; Niu, Shanshan; Wang, Enliang; Chen, Xiangjun

    2018-03-01

    The low count rate of (e, 2e) electron momentum spectroscopy (EMS) has long been a major limitation of its application to the investigation of molecular dynamics. Here we report a new EMS apparatus developed for time-resolved experiments in the nanosecond time scale, in which a double toroidal energy analyzer is utilized to improve the sensitivity of the spectrometer and a nanosecond pulsed electron gun with a repetition rate of 10 kHz is used to obtain an average beam current up to nA. Meanwhile, a picosecond ultraviolet laser with a repetition rate of 5 kHz is introduced to pump the sample target. The time zero is determined by photoionizing the target using a pump laser and monitoring the change of the electron beam current with time delay between the laser pulse and electron pulse, which is influenced by the plasma induced by the photoionization. The performance of the spectrometer is demonstrated by the EMS measurement on argon using a pulsed electron beam, illustrating the potential abilities of the apparatus for investigating the molecular dynamics in excited states when employing the pump-probe scheme.

  19. Timing jitter measurements at the SLC electron source

    International Nuclear Information System (INIS)

    Sodja, J.; Browne, M.J.; Clendenin, J.E.

    1989-03-01

    The SLC thermionic gun and electron source produce a beam of up to 15 /times/ 10 10 /sub e//minus/ in a single S-band bunch. A 170 keV, 2 ns FWHM pulse out of the gun is compressed by means of two subharmonic buncher cavities followed by an S-band buncher and a standard SLAC accelerating section. Ceramic gaps in the beam pipe at the output of the gun allow a measure of the beam intensity and timing. A measurement at these gaps of the timing jitter, with a resolution of <10 ps, is described. 3 refs., 5 figs

  20. Independence and Interdependence: An Analysis of Pre-Service Candidates' Use of Focused Assignments on an Electronic Discussion Forum during the Initial Field Experience

    Science.gov (United States)

    Fisch, Audrey A.; Bennett, Deborah J.

    2011-01-01

    This article describes a case study using an electronic learning platform for creating an interactive learning community through asynchronous discussion to enhance the initial field experience of secondary math and English teacher candidates enrolled in Field Experience. We identified three problems with the field experience course--lack of…

  1. Changing Words: Time and Space in Electronic Literature

    Directory of Open Access Journals (Sweden)

    Paola Di Gennaro

    2015-05-01

    Full Text Available Printed literature and electronic literature, especially hypertexts, bring into play diverse issues of time and space. When approaching them, we should use different critical frameworks, at least in one respect: the analysis of a hypertext cannot forget considerations about time and space in the act of reading – or performing – the text. Hypertexts generate many different possible readings thanks to the changing and shifting links which move in hyperspace. Therefore, if in considering these issues in electronic literature we can obviously apply all the critical categories we use with printed works, here we cannot avoid considering the time and the space that are not “inside” the text but “outside” the text. This essay tries to explain the relationship between these external and internal time-space issues in electronic literature, how they interlink and mutually change, and how the act of reading both modifies and is modified by them. In particular, we will consider the web-based poetry When the Sea Stands Still (1997, by John Cayley and Yang Lian, and Rice (1998, by the artist known as Geniwate, basing the analysis on the studies by Espen Aarseth, Wolfgang Iser, Frank Kermode, Ted Nelson, and Edward Said.

  2. Developers@CERN Forums: Python

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The Developers@CERN Forums second edition took place at the end of May on the topic of Python. How do developers at CERN interact with Python? Which cutting-edge projects are using Python? What were the highlights of this most recent forum?

  3. London International Youth Science Forum

    Science.gov (United States)

    Auty, Geoff

    2010-01-01

    In this article, the author discusses the 2010 London International Youth Science Forum (LIYSF) and shares his experience in attending the forum. Unlike the Harry Messel event in Sydney, which takes place every two years, LIYSF is an annual event. Before moving to Imperial College London, LIYSF was held at the Institute of Electrical Engineers and…

  4. ITU World Youth Forum visits CERN

    CERN Multimedia

    2009-01-01

    About 250 students selected by the International Telecommunication Union (ITU) to participate in the 2009 Youth Forum made CERN a primary destination for this year’s World Youth Forum event. The 250 students participating in the 2009 Youth Forum attend a presentation in the Globe of Science and Innovation.On Tuesday 6 October, the group visited several sites including the Microcosm exhibition and the ATLAS cavern to get a glimpse of what CERN does and the exciting science that is studied here. Since 2001 and every three years, the ITU World Forum brings together young men and women, aged 18-23, to learn about new technologies and the world around them. This year’s group included participants from one hundred and twenty-five different countries. This was the first time that the event involved a visit to CERN. When asked why CERN was a destination, Pascal Biner, organizer of the visit for ITU, explained that CERN was a necessary stop given the Forum’s base in Gen...

  5. CERN Apps meet in a forum

    CERN Multimedia

    Antonella Del Rosso

    2013-01-01

    In the fast-evolving world of mobile apps, creativity and usability are key words. For the time being, the number of CERN apps is quite limited but the situation could quickly change. An information-sharing forum set up by the IT Department is a starting point to channel your creativity with the help of experts, best practices and useful guidelines.   The CAPPS (CERN Apps) Forum was set up about a year ago. Its members come from various departments and meet every two or three months to update each other on the apps that are in preparation, share the latest news on the available software, discuss best practices and so on. “The Forum is open to anybody wanting to develop apps at CERN,” explains David Foster, Deputy Department Head and initiator of the CAPPS Forum. “Developers, communication experts and IT infrastructure experts meet and discuss various topics, from branding-related issues to coding and implementation solutions. The aim is to go forward in a coherent way...

  6. Numerical simulations of time-resolved quantum electronics

    International Nuclear Information System (INIS)

    Gaury, Benoit; Weston, Joseph; Santin, Matthieu; Houzet, Manuel; Groth, Christoph; Waintal, Xavier

    2014-01-01

    Numerical simulation has become a major tool in quantum electronics both for fundamental and applied purposes. While for a long time those simulations focused on stationary properties (e.g. DC currents), the recent experimental trend toward GHz frequencies and beyond has triggered a new interest for handling time-dependent perturbations. As the experimental frequencies get higher, it becomes possible to conceive experiments which are both time-resolved and fast enough to probe the internal quantum dynamics of the system. This paper discusses the technical aspects–mathematical and numerical–associated with the numerical simulations of such a setup in the time domain (i.e. beyond the single-frequency AC limit). After a short review of the state of the art, we develop a theoretical framework for the calculation of time-resolved observables in a general multiterminal system subject to an arbitrary time-dependent perturbation (oscillating electrostatic gates, voltage pulses, time-varying magnetic fields, etc.) The approach is mathematically equivalent to (i) the time-dependent scattering formalism, (ii) the time-resolved non-equilibrium Green’s function (NEGF) formalism and (iii) the partition-free approach. The central object of our theory is a wave function that obeys a simple Schrödinger equation with an additional source term that accounts for the electrons injected from the electrodes. The time-resolved observables (current, density, etc.) and the (inelastic) scattering matrix are simply expressed in terms of this wave function. We use our approach to develop a numerical technique for simulating time-resolved quantum transport. We find that the use of this wave function is advantageous for numerical simulations resulting in a speed up of many orders of magnitude with respect to the direct integration of NEGF equations. Our technique allows one to simulate realistic situations beyond simple models, a subject that was until now beyond the simulation

  7. Time-resolving electron temperature diagnostic for ALCATOR C

    International Nuclear Information System (INIS)

    Fairfax, S.A.

    1984-05-01

    A diagnostic that provides time-resolved central electron temperatures has been designed, built, and tested on the ALCATOR C Tokamak. The diagnostic uses an array of fixed-wavelength x-ray crystal monochromators to sample the x-ray continuum and determine the absolute electron temperature. The resolution and central energy of each channel were chosen to exclude any contributions from impurity line radiation. This document describes the need for such a diagnostic, the design methodology, and the results with typical ALCATOR C plasmas. Sawtooth (m = 1) temperature oscillations were observed after pellet fueling of the plasma. This is the first time that such oscillations have been observed with an x-ray temperature diagnostic

  8. Ultimate response time of high electron mobility transistors

    International Nuclear Information System (INIS)

    Rudin, Sergey; Rupper, Greg; Shur, Michael

    2015-01-01

    We present theoretical studies of the response time of the two-dimensional gated electron gas to femtosecond pulses. Our hydrodynamic simulations show that the device response to a short pulse or a step-function signal is either smooth or oscillating time-decay at low and high mobility, μ, values, respectively. At small gate voltage swings, U 0  = U g  − U th , where U g is the gate voltage and U th is the threshold voltage, such that μU 0 /L < v s , where L is the channel length and v s is the effective electron saturation velocity, the decay time in the low mobility samples is on the order of L 2 /(μU 0 ), in agreement with the analytical drift model. However, the decay is preceded by a delay time on the order of L/s, where s is the plasma wave velocity. This delay is the ballistic transport signature in collision-dominated devices, which becomes important during very short time periods. In the high mobility devices, the period of the decaying oscillations is on the order of the plasma wave velocity transit time. Our analysis shows that short channel field effect transistors operating in the plasmonic regime can meet the requirements for applications as terahertz detectors, mixers, delay lines, and phase shifters in ultra high-speed wireless communication circuits

  9. Take part in the Poster Forum

    CERN Multimedia

    2008-01-01

    The CERN Control Week will run from 17 to 23 May 2008. For the first time, the IT-CO group will be organising a "poster forum" on the theme of process control, which will be held in the main hall of Building 500 in Meyrin, near Restaurant No. 1 (see Bulletin No. 16/2008). If you wish to take part, there is still time to send your posters to Mathias Dutour or Stefan Lueders.

  10. 2008 GRS specialized forum

    International Nuclear Information System (INIS)

    Butz, H.P.

    2008-01-01

    After the successful trial run in 2007, the 2008 GRS Specialized Forum held at the Cologne Wolkenburg on April 7 and 8, 2008 was a full success. GRS, Gesellschaft fuer Anlagen- und Reaktorsicherheit, plans to resume in this way its GRS specialized lectures series with a tradition of many years. Approximately 180 participants from public authorities, licensees, the nuclear industry, research and engineering establishments as well as universities showed their interest in current GRS activities. On 2 days, only GRS experts presented fundamental and GRS-specific approaches in scientific analysis, new research findings, and possibilities of advancing scientific methods under the four headings of Reactor Safety Research and Evaluation, Topical Subjects of Reactor Safety, Radiation Protection Activities, and Repository Safety and Environmental Research. The discussions held after each presentation offered a number of critical, but valuable and welcome, contributions from the different perspectives of the discussants. (orig.)

  11. Two-electron Rabi oscillations in real-time time-dependent density-functional theory

    International Nuclear Information System (INIS)

    Habenicht, Bradley F.; Tani, Noriyuki P.; Provorse, Makenzie R.; Isborn, Christine M.

    2014-01-01

    We investigate the Rabi oscillations of electrons excited by an applied electric field in several simple molecular systems using time-dependent configuration interaction (TDCI) and real-time time-dependent density-functional theory (RT-TDDFT) dynamics. While the TDCI simulations exhibit the expected single-electron Rabi oscillations at a single resonant electric field frequency, Rabi oscillations in the RT-TDDFT simulations are a two-electron process. The existence of two-electron Rabi oscillations is determined both by full population inversion between field-free molecular orbitals and the behavior of the instantaneous dipole moment during the simulations. Furthermore, the Rabi oscillations in RT-TDDFT are subject to an intensity threshold of the electric field, below which Rabi oscillations do not occur and above which the two-electron Rabi oscillations occur at a broad range of frequencies. It is also shown that at field intensities near the threshold intensity, the field frequency predicted to induce Rabi oscillations by linear response TDDFT only produces detuned Rabi oscillations. Instead, the field frequency that yields the full two-electron population inversion and Rabi oscillation behavior is shown to be the average of single-electron transition frequencies from the ground S 0 state and the doubly-excited S 2 state. The behavior of the two-electron Rabi oscillations is rationalized via two possible models. The first model is a multi-photon process that results from the electric field interacting with the three level system such that three level Rabi oscillations may occur. The second model suggests that the mean-field nature of RT-TDDFT induces paired electron propagation

  12. Frontend electronics for high-precision single photo-electron timing using FPGA-TDCs

    Science.gov (United States)

    Cardinali, M.; Dzyhgadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Ugur, C.; Zühlsdorf, M.; Dodokhov, V. Kh.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Düren, M.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Rosner, G.; Achenbach, P.; Corell, O.; Ferretti Bondy, M. I.; Hoek, M.; Lauth, W.; Rosner, C.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

    2014-12-01

    The next generation of high-luminosity experiments requires excellent particle identification detectors which calls for Imaging Cherenkov counters with fast electronics to cope with the expected hit rates. A Barrel DIRC will be used in the central region of the Target Spectrometer of the planned PANDA experiment at FAIR. A single photo-electron timing resolution of better than 100 ps is required by the Barrel DIRC to disentangle the complicated patterns created on the image plane. R&D studies have been performed to provide a design based on the TRB3 readout using FPGA-TDCs with a precision better than 20 ps RMS and custom frontend electronics with high-bandwidth pre-amplifiers and fast discriminators. The discriminators also provide time-over-threshold information thus enabling walk corrections to improve the timing resolution. Two types of frontend electronics cards optimised for reading out 64-channel PHOTONIS Planacon MCP-PMTs were tested: one based on the NINO ASIC and the other, called PADIWA, on FPGA discriminators. Promising results were obtained in a full characterisation using a fast laser setup and in a test experiment at MAMI, Mainz, with a small scale DIRC prototype.

  13. Time-resolved tomographic images of a relativistic electron beam

    International Nuclear Information System (INIS)

    Koehler, H.A.; Jacoby, B.A.; Nelson, M.

    1984-07-01

    We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0 0 , 61 0 , and 117 0 . The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse

  14. Combined time-lapse cinematography and immuno-electron microscopy.

    Science.gov (United States)

    Balfour, B M; Goscicka, T; MacKenzie, J L; Gautam, A; Tate, M; Clark, J

    1990-04-01

    A method was developed to record interactions between mobile non-adherent immunocytes by time-lapse cinematography and then to study the same cells by immuno-electron microscopy, using monoclonal antibodies against surface components. For this purpose a modified stage was designed to fit an inverted microscope. The attachment included a device to cool the culture chamber with N2 gas, a micro-injector for monoclonal antibody and immuno-gold treatment, and two pairs of washing needles to change the medium without disturbance. The technique was first employed to study the formation of aggregates around the antigen-presenting cells in cultures containing cells from hyper-immunized animals. Recently peripheral blood cells from normal subjects and patients with immune deficiency syndromes were stimulated with pokeweed mitogen, cluster formation was recorded, and the cells were processed for immuno-electron microscopy.

  15. Electron scattering times in ZnO based polar heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Falson, J., E-mail: j.falson@fkf.mpg.de [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656 (Japan); Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561 (Japan); Max Planck Institute for Solid State Research, D-70569 Stuttgart (Germany); Kozuka, Y. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656 (Japan); Smet, J. H. [Max Planck Institute for Solid State Research, D-70569 Stuttgart (Germany); Arima, T. [Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561 (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Tsukazaki, A. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); PRESTO, Japan Science and Technology Agency (JST), Tokyo 102-0075 (Japan); Kawasaki, M. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656 (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan)

    2015-08-24

    The remarkable historic advances experienced in condensed matter physics have been enabled through the continued exploration and proliferation of increasingly richer and cleaner material systems. In this work, we report on the scattering times of charge carriers confined in state-of-the-art MgZnO/ZnO heterostructures displaying electron mobilities in excess of 10{sup 6} cm{sup 2}/V s. Through an examination of low field quantum oscillations, we obtain the effective mass of charge carriers, along with the transport and quantum scattering times. These times compare favorably with high mobility AlGaAs/GaAs heterostructures, suggesting the quality of MgZnO/ZnO heterostructures now rivals that of traditional semiconductors.

  16. APES: Acute Precipitating Electron Spectrometer - A High Time Resolution Monodirectional Magnetic Deflection Electron Spectrometer

    Science.gov (United States)

    Michell, R. G.; Samara, M.; Grubbs, G., II; Ogasawara, K.; Miller, G.; Trevino, J. A.; Webster, J.; Stange, J.

    2016-01-01

    We present a description of the Acute Precipitating Electron Spectrometer (APES) that was designed and built for the Ground-to-Rocket Electron Electrodynamics Correlative Experiment (GREECE) auroral sounding rocket mission. The purpose was to measure the precipitating electron spectrum with high time resolution, on the order of milliseconds. The trade-off made in order to achieve high time resolution was to limit the aperture to only one look direction. The energy selection was done by using a permanent magnet to separate the incoming electrons, such that the different energies would fall onto different regions of the microchannel plate and therefore be detected by different anodes. A rectangular microchannel plate (MCP) was used (15 mm x 100 mm), and there was a total of 50 discrete anodes under the MCP, each one 15 mm x 1.5 mm, with a 0.5 mm spacing between anodes. The target energy range of APES was 200 eV to 30 keV.

  17. ECNS '99 - Young scientists forum

    DEFF Research Database (Denmark)

    Ceretti, M.; Janssen, S.; McMorrow, D.F.

    2000-01-01

    The Young Scientists Forum is a new venture for ECNS and follows the established tradition of an active participation by young scientists in these conferences. At ECNS '99 the Young Scientists Forum brought together 30 young scientists from 13 European countries. In four working groups, they disc......The Young Scientists Forum is a new venture for ECNS and follows the established tradition of an active participation by young scientists in these conferences. At ECNS '99 the Young Scientists Forum brought together 30 young scientists from 13 European countries. In four working groups......, they discussed emerging scientific trends in their areas of expertise and the instrumentation required to meet the scientific challenges. The outcome was presented in the Young Scientists Panel on the final day of ECNS '99. This paper is a summary of the four working group reports prepared by the Group Conveners...

  18. Fagligt Forum ved en skillevej

    DEFF Research Database (Denmark)

    Bjerg, Claus

    2008-01-01

    Med cvu-bibliotekernes overgang til professionshøjskoler ændres det biblioteksfaglige landskab. Det har Fagligt Forum taget konsekvensen af og nedlægger sig selv i løbet af 2000......Med cvu-bibliotekernes overgang til professionshøjskoler ændres det biblioteksfaglige landskab. Det har Fagligt Forum taget konsekvensen af og nedlægger sig selv i løbet af 2000...

  19. Forum, Dedicated to Inclusive Education

    Directory of Open Access Journals (Sweden)

    Vachkov I.V.

    2015-06-01

    Full Text Available 26 – 27 of February 2015 in Kazan, in the University of Management “TISBI” been held National (All-Russian forum of promotion of ideas and principles of inclusive education (with international participants “Study and live together: open space of inclusion”. During the work of Forum the most topical questions of inclusive education implement in Russian Federation been discussed.

  20. Development of time-resolved electron momentum spectroscopy. Toward real-time imaging of frontier electrons in molecular reactions

    International Nuclear Information System (INIS)

    Yamazaki, M.; Takahashi, M.

    2016-01-01

    This report will introduce a new experimental technique to readers, which we would like to propose towards advances in the field of molecular reaction dynamics. It is time-resolved electron momentum spectroscopy and aims to take in momentum space snapshots of the rapid change of molecular orbitals, which is the driving force behind any structural changes occurring in transient molecules. Following a description of the working principle of the technique, some preliminary result will be presented in order to illustrate the current performance of the apparatus. (author)

  1. Sample acceptance time criteria, electronic issue and alloimmunisation in thalassaemia.

    Science.gov (United States)

    Trompeter, S; Baxter, L; McBrearty, M; Zatkya, E; Porter, J

    2015-12-01

    To determine the safety of a 1-week acceptance criteria of sample receipt in laboratory to transfusion commencement in transfusion dependent thalassaemia with respect to alloimmunisation. To determine the safety of electronic issue of blood components in such a setting. Retrospective audit of alloimmunisation (1999-2012) and blood exposure in registered thalassaemia patients at a central London thalassaemia centre where the acceptance criteria for the group and save sample from arrival in the laboratory to the time of issue of blood for transfusion for someone who has been transfused in the last 28 days was 1 week, and there was electronic issue protocol for patients who have always had a negative antibody screen (other than temporary positivity in pregnant women receiving prophylactic anti-D or anti Le-a, Anti Le-b and Anti P1 that are no longer detectable). There were 133 patients with thalassemia variants regularly attending UCLH for review. A total of 105 patients had transfusion dependent thalassaemia (TDT) (7 E-beta thalassaemia, 98 beta thalassaemia major). Ten of the 84 patients who received their transfusions at UCLH were alloimmunised. Seven of them had been alloimmunised prior to arrival at UCLH. Only two patients developed antibodies at UCLH during this period. The prevalence of alloantibody formation of 2% in UCLH transfused patients, with presumptive incidence of 0.01 alloantibodies per 100 units or 0·001 immunisations per person per year compares favourably with other reported series and suggests that 1 week interval with appropriate electronic issue is acceptable practice. © 2015 British Blood Transfusion Society.

  2. Novel Front-end Electronics for Time Projection Chamber Detectors

    CERN Document Server

    García García, Eduardo José

    This work has been carried out in the European Organization for Nuclear Research (CERN) and it was supported by the European Union as part of the research and development towards the European detector the (EUDET) project, specifically for the International Linear Collider (ILC). In particle physics there are several different categories of particle detectors. The presented design is focused on a particular kind of tracking detector called Time Projection Chamber (TPC). The TPC provides a three dimensional image of electrically charged particles crossing a gaseous volume. The thesis includes a study of the requirements for future TPC detectors summarizing the parameters that the front-end readout electronics must fulfill. In addition, these requirements are compared with respect to the readouts used in existing TPC detectors. It is concluded that none of the existing front-end readout designs fulfill the stringent requirements. The main requirements for future TPC detectors are high integration, an increased n...

  3. Modeling of electron time variations in the radiation belts

    International Nuclear Information System (INIS)

    Chan, K.W.; Teague, M.J.; Schofield, N.J.; Vette, J.I.

    1979-01-01

    A review of the temporal variation in the trapped electron population of the inner and outer radiation zones is presented. Techniques presently used for modeling these zones are discussed and their deficiencies identified. An intermediate region is indicated between the zones in which the present modeling techniques are inadequate due to the magnitude and frequency of magnetic storms. Future trends are examined, and it is suggested that modeling of individual magnetic storms may be required in certain L bands. An analysis of seven magnetic storms is presented, establishing the independence of the depletion time of the storm flux and the storm magnitude. Provisional correlation between the storm magnitude and the Dst index is demonstrated

  4. Electronic eye occluder with time-counting and reflection control

    Science.gov (United States)

    Karitans, V.; Ozolinsh, M.; Kuprisha, G.

    2008-09-01

    In pediatric ophthalmology 2 - 3 % of all the children are impacted by a visual pathology - amblyopia. It develops if a clear image isn't presented to the retina during an early stage of the development of the visual system. A common way of treating this pathology is to cover the better-seeing eye to force the "lazy" eye to learn seeing. However, children are often reluctant to wear such an occluder because they are ashamed or simply because they find it inconvenient. This fact requires to find a way how to track the regime of occlusion because results of occlusion is a hint that the actual regime of occlusion isn't that what the optometrist has recommended. We design an electronic eye occluder that allows to track the regime of eye occlusion. We employ real-time clock DS1302 providing time information from seconds to years. Data is stored in the internal memory of the CPU (EEPROM). The MCU (PIC16F676) switches on only if a mechanical switch is closed and temperature has reached a satisfactory level. The occlusion is registered between time moments when the infrared signal appeared and disappeared.

  5. Frontend electronics for high-precision single photo-electron timing using FPGA-TDCs

    Energy Technology Data Exchange (ETDEWEB)

    Cardinali, Matteo [Helmholtz Institut Mainz (Germany); Collaboration: PANDA Cherenkov-Collaboration

    2014-07-01

    The next generation of high-luminosity experiments requires excellent Particle Identification (PID) detectors which calls for Imaging Cherenkov counters with fast electronics to cope with the expected data rates. The planned PANDA experiment at FAIR expects average interaction rates of 20 MHz. A Barrel DIRC will provide PID in the central region of the Target Spectrometer. A single photo-electron timing resolution of better than 100 ps is projected for the Barrel DIRC to disentangle the complicated patterns created by the focusing optics on the image plane. The typically large amount of readout channels (approx 15,000 in case of the PANDA Barrel DIRC) places non-negligible limits on size and power consumption of the Front-End Electronics (FEE). The proposed design is based on the TRBv3 readout using FPGA-TDCs with a precision better than 20 ps RMS and custom FEE with high-bandwidth pre-amplifiers and fast discriminators. Two types of FEE cards optimised for reading out 64-channel Photonis Planacon MCP-PMTs were tested: one based on the NINO ASIC developed for the ALICE RPC readout and the other, called PaDiWa, using FPGA-based discriminators. Both types of FEE cards were tested with a small DIRC prototype comprising a radiator bar with focusing lens and an oil-filled expansion volume instrumented with 6 Planacon 64-channel MCP-PMTs. In the presentation the result of a test experiment performed at MAMI B, Mainz, are addressed.

  6. Internet discussion forums as part of a student-centred teaching concept of pharmacology.

    Science.gov (United States)

    Sucha, Michael; Engelhardt, Stefan; Sarikas, Antonio

    2013-01-01

    The world wide web opens up new opportunities to interconnect electronic and classroom teaching and to promote active student participation. In this project article we describe the use of internet discussion forums as part of a student-centred teaching concept of pharmacology and discuss its advantages and disadvantages based on evaluation data and current literature. Final year medical students at the Technische Universität München (Munich, Germany) with the elective pharmacology moderated an internet forum that allowed all students to discuss pharmacology-related questions. Evaluation results of forum participants and elective students demonstrated a learning benefit of internet forums in pharmacology teaching. Internet discussion forums offer an easy-to-implement and effective way to actively engage students and increase the learning benefit of electronic and classroom teaching in pharmacology.

  7. Forum-ing: Signature practice for public theological discourse

    Directory of Open Access Journals (Sweden)

    Edward P. Wimberly

    2014-05-01

    Full Text Available This article introduces a unique model for public theological conversation and discourse, which was developed by the Concerned Black Clergy of Atlanta (CBC. It was a model developed in response to the problems of poverty, homelessness, and the ‘missing and murdered children’ victimised in Atlanta, Georgia in the United States of America in the early 1980s. It was originally organised to respond to the economic, financial, spiritual, emotional, employment, housing and resource needs of the underserved poor. This unique practice is called forum-ing. The forum meets every Monday morning, except when there is a national holiday. It has operated 30 consecutive years. The forum has a series of presentations, including the opening prayer, self-introductions of each person, a report of the executive director, special presentations from selected community groups, reports, and then questions and answers. The end result is that those attending engage in a process of discourse that enables them to internalise new ideas, approaches, and activities for addressing poverty and injustice in the community. Key to forum-ing for the 21st century is that it is a form of public practical theology rooted and grounded in non-violence growing out of the civil rights movement of the 1950s and 1960s in the United States. The overall purpose of this article is to contribute to the effort of the Faculty of Theology at the University of Pretoria (South Africa to identify those variables that will assist religious leaders in South Africa to develop public conversational spaces to enhance democratic participation. This article presents one model from the African American community in Atlanta, Georgia. The hope is to lift up key variables that might assist in the practical and pastoral theological conversation taking place in South Africa at present.

  8. Advances in imaging and electron physics time resolved electron diffraction for chemistry, biology and material science

    CERN Document Server

    Hawkes, Peter W

    2014-01-01

    Advances in Imaging & Electron Physics merges two long-running serials-Advances in Electronics & Electron Physics and Advances in Optical & Electron Microscopy. The series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Contributions from leading authorities Informs and updates on all the latest developments in the field.

  9. 27 CFR 73.34 - When is an electronically submitted form considered timely filed?

    Science.gov (United States)

    2010-04-01

    ... AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURES AND PRACTICES ELECTRONIC SIGNATURES; ELECTRONIC SUBMISSION OF FORMS Electronic Filing of Documents with TTB § 73.34 When is an electronically submitted form considered timely filed? If you submit a form to our electronic...

  10. TIME-DEPENDENT ELECTRON ACCELERATION IN BLAZAR TRANSIENTS: X-RAY TIME LAGS AND SPECTRAL FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tiffany R.; Becker, Peter A. [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030-4444 (United States); Finke, Justin D., E-mail: pbecker@gmu.edu, E-mail: tlewis13@gmu.edu, E-mail: justin.finke@nrl.navy.mil [U.S. Naval Research Laboratory, Code 7653, 4555 Overlook Avenue SW, Washington, DC 20375-5352 (United States)

    2016-06-20

    Electromagnetic radiation from blazar jets often displays strong variability, extending from radio to γ -ray frequencies. In a few cases, this variability has been characterized using Fourier time lags, such as those detected in the X-rays from Mrk 421 using Beppo SAX. The lack of a theoretical framework to interpret the data has motivated us to develop a new model for the formation of the X-ray spectrum and the time lags in blazar jets based on a transport equation including terms describing stochastic Fermi acceleration, synchrotron losses, shock acceleration, adiabatic expansion, and spatial diffusion. We derive the exact solution for the Fourier transform of the electron distribution and use it to compute the Fourier transform of the synchrotron radiation spectrum and the associated X-ray time lags. The same theoretical framework is also used to compute the peak flare X-ray spectrum, assuming that a steady-state electron distribution is achieved during the peak of the flare. The model parameters are constrained by comparing the theoretical predictions with the observational data for Mrk 421. The resulting integrated model yields, for the first time, a complete first-principles physical explanation for both the formation of the observed time lags and the shape of the peak flare X-ray spectrum. It also yields direct estimates of the strength of the shock and the stochastic magnetohydrodynamical wave acceleration components in the Mrk 421 jet.

  11. 17. telekomunikacioni forum TELFOR 2009

    Directory of Open Access Journals (Sweden)

    Nebojša N. Gaćeša

    2010-04-01

    Full Text Available U Beogradu je 24, 25. i 26. novembra 2009. godine, u Sava centru, održan 17. telekomunikacioni forum TELFOR 2009, u organizaciji Društva za telekomunikacije – Beograd, „Telekom Srbija“ a. d., JP PTT saobraćaja „Srbija“, Elektrotehničkog fakulteta Univerziteta u Beogradu i IEEE Serbia & Montenegro ComSoc Chapter and Section. Telekomunikacioni forum TELFOR organizuje se sedamnaesti put kao domaći i regionalni godišnji skup stručnjaka koji rade u oblastima telekomunikacija i informacionih tehnologija. Učesnici su uglavnom telekomunikacioni inženjeri, ali i ekonomisti, pravnici, menadžeri, operatori i drugi. Na taj način TELFOR predstavlja forum u okviru kojeg se razmatraju sva relevantna pitanja telekomunikacija: tehnička, razvojna, regulatorna i ekonomska, pitanja proizvodnje opreme, usluga, servisa i funkcionisanja sistema.

  12. Application of time release electron donors and electron acceptors for accelerated bioremediation

    International Nuclear Information System (INIS)

    Joksimovich, V.; Koenigsberg, S.

    2002-01-01

    Currently, there are limited options for cost effective approaches to soil and groundwater contamination. One technology that has proven its potential involves the use of time release electron acceptors to accelerate the natural bioattenuation of aerobically degradable compounds and time release electron donors to accelerate the natural bioattenuation of anaerobic compounds. This technology enjoys its reputations as a sensible strategy for engineering accelerated bioattenuation, because it delivers results while 1) limiting or eliminating design, capital and management costs and 2) allowing for the engineering of a low-impact application and a subsequently invisible remediation process. Oxygen Release Compound (ORC ) is proprietary formulation of intercalated magnesium peroxide that releases oxygen slowly, for about a year, and facilitates the aerobic degradation of a range of environmental contaminants including petroleum hydrocarbons, certain chlorinated hydrocarbons, ether oxygenates and nitroaromatics. The history of ORC's introduction and acceptance represents a model for the evolution of an innovative technology. This statement comes by virtue of the fact that since 1994 ORC has been used on over 7000 sites worldwide and has been the subject of an extensive body of literature. Hydrogen Release Compound (HRC) is also a proprietary polylactate ester that is food grade and, upon being deposited into the aquifer, is slowly hydrolyzed to release lactic acid and other organic acid derivatives for about one to two years. The organic acids are fermented to hydrogen, which in turn donates electrons that drive reductive bioattenuation processes. This is primarily directed at a wide range of chlorinated hydrocarbons, but can be applied to the remediation of metals by redox induced precipitation. HRC has now been used on over 220 sites, which we believe make it the most widely used electron donor for accelerating bioattenuation. ORC and HRC can be configured as a

  13. Lifetime measurements in transitional nuclei by fast electronic scintillation timing

    Science.gov (United States)

    Caprio, M. A.; Zamfir, N. V.; Casten, R. F.; Amro, H.; Barton, C. J.; Beausang, C. W.; Cooper, J. R.; Gürdal, G.; Hecht, A. A.; Hutter, C.; Krücken, R.; McCutchan, E. A.; Meyer, D. A.; Novak, J. R.; Pietralla, N.; Ressler, J. J.; Berant, Z.; Brenner, D. S.; Gill, R. L.; Regan, P. H.

    2002-10-01

    A new generation of experiments studying nuclei in spherical-deformed transition regions has been motivated by the introduction of innovative theoretical approaches to the treatment of these nuclei. The important structural signatures in the transition regions, beyond the basic yrast level properties, involve γ-ray transitions between low-spin, non-yrast levels, and so information on γ-ray branching ratios and absolute matrix elements (or level lifetimes) for these transitions is crucial. A fast electronic scintillation timing (FEST) system [H. Mach, R. L. Gill, and M. Moszyński, Nucl. Instrum. Methods A 280, 49 (1989)], making use of BaF2 and plastic scintillation detectors, has been implemented at the Yale Moving Tape Collector for the measurement of lifetimes of states populated in β^ decay. Experiments in the A100 (Pd, Ru) and A150 (Dy, Yb) regions have been carried out, and a few examples will be presented. Supported by the US DOE under grants and contracts DE-FG02-91ER-40609, DE-FG02-88ER-40417, and DE-AC02-98CH10886 and by the German DFG under grant Pi 393/1.

  14. Science at the Time-scale of the Electron

    Science.gov (United States)

    Murnane, Margaret

    2010-03-01

    Replace this text with your abstract Ever since the invention of the laser 50 years ago and its application in nonlinear optics, scientists have been striving to extend coherent laser beams into the x-ray region of the spectrum. Very recently however, the prospects for tabletop coherent sources, with attosecond pulse durations, at very short wavelengths even in the hard x-ray region of the spectrum at wavelengths movie of how electron orbitals in a molecule change shape as a molecule breaks apart, following how fast a magnetic material can flip orientation, understanding how fast heat flows in a nanocircuit, or building a microscope without lenses. [4pt] [1] T. Popmintchev et al., ``Phase matched upconversion of coherent ultrafast laser light into the soft and hard x-ray regions of the spectrum'', PNAS 106, 10516 (2009). [0pt] [2] C. LaOVorakiat et al., ``Ultrafast Soft X-Ray Magneto-Optics at the M-edge Using a Tabletop High-Harmonic Source'', Physical Review Letters 103, 257402 (2009). [0pt] [3] M. Siemens et al. ``Measurement of quasi-ballistic heat transport across nanoscale interfaces using ultrafast coherent soft x-ray beams'', Nature Materials 9, 26 (2010). [0pt] [4] K. Raines et al., ``Three-dimensional structure determination from a single view,'' Nature 463, 214 (2010). [0pt] [5] W. Li et al., ``Time-resolved Probing of Dynamics in Polyatomic Molecules using High Harmonic Generation'', Science 322, 1207 (2008).

  15. 4. heat pump forum. Politics, market, finances, marketing and sales. Proceedings 2006; 4. Forum Waermepumpe. Politik, Markt, Finanzierung, Marketing und Vertrieb. Tagungsband 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The fourth heat pump forum is characterised by the latest state-of-the art. For the first time you will receive as forum documents not only the proceedings but also an updated agenda, supplemented by the latest business field information and an overview of distinctive achievements of the company Solarpraxis AG. Highly qualified representatives will be present at the plenary discussion on both forum days for the first time, too. This year the heat pump forum again consists of talks, impulse presentations, discussions and workshops dealing in many different ways and based on a proven concept with the topics politics, market, finances, marketing and sales. In terms of contents the forum covers all topics, which are of importance for a further growth of the heat pump field: political frame conditions as basis for a stable home market, heat pumps in old buildings, marketing strategies as well as quality assurance and practice. (orig.)

  16. Emotional isolation in BBC Forum

    International Nuclear Information System (INIS)

    Sienkiewicz, J; Chmiel, A

    2014-01-01

    We analyze emotionally annotated massive data from BBC Forum and examine properties of the isolation phenomenon of negative and positive users. Our results show the existence of a percolation threshold dependent on the average emotional value in the network of negatively charged nodes

  17. 11. Rostock bioenergy forum. Proceedings

    International Nuclear Information System (INIS)

    Nelles, Michael

    2017-01-01

    The seven main focus of the bioenergy forum were: 1. Political regulation and its consequences; 2. Flexible energy supply; 3. Biorefineries for the use of residues from bioenergy production; 4. Process optimization biogas; 5. Alternative substrates for biogas production; 6. Cross-sectoral bioenergy concept; 7. Transport sector (biofuels). Five lectures are separately analyzed for this database. [de

  18. Real Time Space Radiation Effects in Electronic Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The effects that solar particle events can have on operational electronic systems is a significant concern for all missions, but especially for those beyond Low...

  19. Cold Electronics for Giant Liquid Argon Time Projection Chambers

    International Nuclear Information System (INIS)

    Radeka, V.; De Geronimo, G.; Chen, H.; Deptuch, G.; Lanni, F.; Li, S.; Nambiar, N.; Rescia, S.; Thorn, C.; Yarema, R.; Yu, B.

    2011-01-01

    The choice between cold and warm electronics (inside or outside the cryostat) in very large LAr TPCs (>5-10 ktons) is not an electronics issue, but it is rather a major cryostat design issue. This is because the location of the signal processing electronics has a direct and far reaching effect on the cryostat design, an indirect effect on the TPC electrode design (sense wire spacing, wire length and drift distance), and a significant effect on the TPC performance. All these factors weigh so overwhelmingly in favor of the cold electronics that it remains an optimal solution for very large TPCs. In this paper signal and noise considerations are summarized, the concept of the readout chain is described, and the guidelines for design of CMOS circuits for operation in liquid argon (at ∼89 K) are discussed.

  20. Determination of equilibrium electron temperature and times using an electron swarm model with BOLSIG+ calculated collision frequencies and rate coefficients

    International Nuclear Information System (INIS)

    Pusateri, Elise N.; Morris, Heidi E.; Nelson, Eric M.; Ji, Wei

    2015-01-01

    Electromagnetic pulse (EMP) events produce low-energy conduction electrons from Compton electron or photoelectron ionizations with air. It is important to understand how conduction electrons interact with air in order to accurately predict EMP evolution and propagation. An electron swarm model can be used to monitor the time evolution of conduction electrons in an environment characterized by electric field and pressure. Here a swarm model is developed that is based on the coupled ordinary differential equations (ODEs) described by Higgins et al. (1973), hereinafter HLO. The ODEs characterize the swarm electric field, electron temperature, electron number density, and drift velocity. Important swarm parameters, the momentum transfer collision frequency, energy transfer collision frequency, and ionization rate, are calculated and compared to the previously reported fitted functions given in HLO. These swarm parameters are found using BOLSIG+, a two term Boltzmann solver developed by Hagelaar and Pitchford (2005), which utilizes updated cross sections from the LXcat website created by Pancheshnyi et al. (2012). We validate the swarm model by comparing to experimental effective ionization coefficient data in Dutton (1975) and drift velocity data in Ruiz-Vargas et al. (2010). In addition, we report on electron equilibrium temperatures and times for a uniform electric field of 1 StatV/cm for atmospheric heights from 0 to 40 km. We show that the equilibrium temperature and time are sensitive to the modifications in the collision frequencies and ionization rate based on the updated electron interaction cross sections

  1. Chaos in Electronic Circuits: Nonlinear Time Series Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wheat, Jr., Robert M. [Kennedy Western Univ., Cheyenne, WY (United States)

    2003-07-01

    Chaos in electronic circuits is a phenomenon that has been largely ignored by engineers, manufacturers, and researchers until the early 1990’s and the work of Chua, Matsumoto, and others. As the world becomes more dependent on electronic devices, the detrimental effects of non-normal operation of these devices becomes more significant. Developing a better understanding of the mechanisms involved in the chaotic behavior of electronic circuits is a logical step toward the prediction and prevention of any potentially catastrophic occurrence of this phenomenon. Also, a better understanding of chaotic behavior, in a general sense, could potentially lead to better accuracy in the prediction of natural events such as weather, volcanic activity, and earthquakes. As a first step in this improvement of understanding, and as part of the research being reported here, methods of computer modeling, identifying and analyzing, and producing chaotic behavior in simple electronic circuits have been developed. The computer models were developed using both the Alternative Transient Program (ATP) and Spice, the analysis techniques have been implemented using the C and C++ programming languages, and the chaotically behaving circuits developed using “off the shelf” electronic components.

  2. A Proposed Model for Authenticating Knowledge Transfer in Online Discussion Forums

    Science.gov (United States)

    Tucker, Jan P.; YoungGonzaga, Stephanie; Krause, Jaclyn

    2014-01-01

    Discussion forums are often utilized in the online classroom to build a sense of community, encourage collaboration and exchange, and measure time on task. A review of the literature revealed that there is little research that examines the role of the online discussion forum as a mechanism for knowledge transfer. Researchers reviewed 21 course…

  3. Real-time control of electronic motion: Application to NaI

    DEFF Research Database (Denmark)

    Grønager, Michael; Henriksen, Niels Engholm

    1998-01-01

    + + I- depends on the electron distribution (i.e., where the electron "sits") prior to the time where the bond is broken by a subpicosecond half-cycle unipolar electromagnetic pulse. Thus we control, in real time, which nucleus one of the valence electrons will follow after the bond is broken. (C) 1998......We study theoretically the electronic and nuclear dynamics in NaI. After a femtosecond pulse has prepared a wave packet in the first excited state, we consider the adiabatic and the nonadiabatic electronic dynamics and demonstrate explicitly that a nonstationary electron is created in Na...

  4. Time-dependent approach to electron scattering and ionization in the s-wave model

    International Nuclear Information System (INIS)

    Ihra, W.; Draeger, M.; Handke, G.; Friedrich, H.

    1995-01-01

    The time-dependent Schroedinger equation is integrated for continuum states of two-electron atoms in the framework of the s-wave model, in which both electrons are restricted to having vanishing individual orbital angular momenta. The method is suitable for studying the time evolution of correlations in the two-electron wave functions and yields probabilities for elastic and inelastic electron scattering and for electron-impact ionization. The spin-averaged probabilities for electron-impact ionization of hydrogen in the s-wave model reproduce the shape of the experimentally observed integrated ionization cross section remarkably well for energies near and above the maximum

  5. Nuclear waste disposal educational forum

    International Nuclear Information System (INIS)

    1982-01-01

    In keeping with a mandate from the US Congress to provide opportunities for consumer education and information and to seek consumer input on national issues, the Department of Energy's Office of Consumer Affairs held a three-hour educational forum on the proposed nuclear waste disposal legislation. Nearly one hundred representatives of consumer, public interest, civic and environmental organizations were invited to attend. Consumer affairs professionals of utility companies across the country were also invited to attend the forum. The following six papers were presented: historical perspectives; status of legislation (Senate); status of legislation (House of Representatives); impact on the legislation on electric utilities; impact of the legislation on consumers; implementing the legislation. All six papers have been abstracted and indexed for the Energy Data Base

  6. EUFOREA Rhinology Research Forum 2016

    DEFF Research Database (Denmark)

    Hellings, P W; Akdis, C A; Bachert, C

    2017-01-01

    The first European Rhinology Research Forum organized by the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) was held in the Royal Academy of Medicine in Brussels on 17th and 18th November 2016, in collaboration with the European Rhinologic Society (ERS......) and the Global Allergy and Asthma European Network (GA2LEN). One hundred and thirty participants (medical doctors from different specialties, researchers, as well as patients and industry representatives) from 27 countries took part in the multiple perspective discussions including brainstorming sessions on care...... pathways and research needs in rhinitis and rhinosinusitis. The debates started with an overview of the current state of the art, including weaknesses and strengths of the current practices, followed by the identification of essential research needs, thoroughly integrated in the context of Precision...

  7. Online Groups and Patient Forums

    OpenAIRE

    Dosani, Sabina; Harding, Claire; Wilson, Simon

    2014-01-01

    Online mental health support forums are becoming increasingly popular and there is evidence that they are useful: particularly for providing anonymous support and filling information gaps. However, there are also very real concerns about negative outcomes for users. One online mental health service, Big White Wall, manages these risks and supports its members through the provision of 24 hour professional moderation. Comparison of Big White Wall’s member population with the population of one L...

  8. The Most Likely Nemesis to Timely, Accurate Electronic Information

    Science.gov (United States)

    2002-02-04

    NETWORKS, TRAINING, COMMERCIAL OFF-THE-SHELF, INFORMATION TECHNOLOGY , INTERNET , COMMUNICATIONS EQUIPMENT, ELECTRONIC INFORMATION 15.Abstract...infected over 200,000 Internet computers . While the objective appeared to be to create a log-jam on the Internet and not actually alter information on...Brigadier General Robert M. Shea, USMC, Director for Command, Control, Communications and Computers for the Marine Corps, cites information overload problems

  9. Determination of Longitudinal Electron Bunch Lengths on Picosecond Time Scales

    CERN Document Server

    Martínez, C; Calviño, F

    1999-01-01

    At CERN (European Laboratory for Particle Physics) the CLIC (Compact Linear Collider) study is pursuing the design of an electron-positron high-energy linear collider using an innovative concept for the RF (Radio Frequency) power production, the socalled two-beam acceleration scheme. In order to keep the length of the collider in a reasonable range while being able of accelerating electrons and positrons up to 5 TeV, the normal-conducting accelerating structures should operate at very high frequency (in this case 30 GHz). The RF power necessary to feed the accelerating cavities is provided by a second electron beam, the drive beam, running parallel to the main beam. The CLIC Test Facility (CTF) was build with the main aim of studying and demonstrating the feasibility of the two beam acceleration scheme and technology. It is composed of two beams, the drive beam that will generate the 30 GHz RF power and the main beam which will be accelerated by this power. In order to have a good efficiency for the power gen...

  10. MCNP4C2, Coupled Neutron, Electron Gamma 3-D Time-Dependent Monte Carlo Transport Calculations

    International Nuclear Information System (INIS)

    2002-01-01

    1 - Description of program or function: MCNP is a general-purpose, continuous-energy, generalized geometry, time-dependent, coupled neutron-photon-electron Monte Carlo transport code system. MCNP4C2 is an interim release of MCNP4C with distribution restricted to the Criticality Safety community and attendees of the LANL MCNP workshops. The major new features of MCNP4C2 include: - Photonuclear physics; - Interactive plotting; - Plot superimposed weight window mesh; - Implement remaining macro-body surfaces; - Upgrade macro-bodies to surface sources and other capabilities; - Revised summary tables; - Weight window improvements. See the MCNP home page more information http://www-xdiv.lanl.gov/XCI/PROJECTS/MCNP with a link to the MCNP Forum. See the Electronic Notebook at http://www-rsicc.ornl.gov/rsic.html for information on user experiences with MCNP. 2 - Methods:MCNP treats an arbitrary three-dimensional configuration of materials in geometric cells bounded by first- and second-degree surfaces and some special fourth-degree surfaces. Pointwise continuous-energy cross section data are used, although multigroup data may also be used. Fixed-source adjoint calculations may be made with the multigroup data option. For neutrons, all reactions in a particular cross-section evaluation are accounted for. Both free gas and S(alpha, beta) thermal treatments are used. Criticality sources as well as fixed and surface sources are available. For photons, the code takes account of incoherent and coherent scattering with and without electron binding effects, the possibility of fluorescent emission following photoelectric absorption, and absorption in pair production with local emission of annihilation radiation. A very general source and tally structure is available. The tallies have extensive statistical analysis of convergence. Rapid convergence is enabled by a wide variety of variance reduction methods. Energy ranges are 0-60 MeV for neutrons (data generally only available up to

  11. Optically isolated electronic trigger system for experiments on a subnanosecond time scale with a pulsed Van de Graaff electron accelerator

    International Nuclear Information System (INIS)

    Luthjens, L.H.; Vermeulen, M.J.W.; Hom, M.L.

    1980-01-01

    An optically isolated electronic trigger system for a pulsed Van de Graaff electron accelerator, producing an external pretrigger pulse 75 ns before arrival of the electron pulse at the target, is described. The total time jitter between trigger signal and electron pulse is 50 ps. The measurement of optical and electrical transients on a subnanosecond time scale with a sequential sampling oscilloscope is demonstrated. The contribution of various parts of the equipment to the total jitter is discussed. Those contributions to the jitter due to the electron transit time fluctuations in the accelerator assuming a constant acceleration voltage gradient and to the shot noise in the photomultiplier detector of the trigger system are calculated to be 5 ps and 12 to 21 ps respectively. Comparison with the experimental results leads to the conclusion that a considerable part of the total jitter may be attributed to acceleration voltage gradient fluctuations, to accelerator vibrations and possibly to density fluctuations in the insulation gas. Possible improvements of the trigger system are discussed. The apparatus is used for pulse radiolysis experiments with subnanosecond time resolution down to 100 ps in combination with subnanosecond time duration electron pulses

  12. Onco forum in urology

    International Nuclear Information System (INIS)

    Richaud, P.; Hennequin, Ch.

    2009-01-01

    Objective: To present to the radiation oncologist the main advances in prostate cancer in the last year Methodology. - A review of the main congress in uro-oncology (ASCO, ASTRO, AUA, EAU) and international literature Results. - The increase in the incidence of prostate cancer without increasing in mortality must be a signal for oncologist to propose active surveillance to the patients without bad prognostic factors. Use of bio-markers could probably facilitate the selection of patients needing treatment. After prostatectomy, adjuvant radiotherapy could decrease the biochemical relapse rate but also the risk of distant metastasis, particularly for pT3 R1 patients ; but the optimal time to deliver this post-operative radiotherapy is discussed : immediately after surgery or delayed in case of PSA relapse (≥ 0,2 ng/ml). For locally advanced disease, combination of radiotherapy and long-term androgen deprivation improved survival over hormonal treatment alone. But duration of androgen deprivation must be adapted to the co-morbidities of the patient because of the risk of metabolic syndrome. The value of dose escalation in association with hormonal treatment must be defined. Conclusion. - Important advances in prostate cancer management have been made during the last months, but inclusion of patients into on-going prospective studies is still important to continue to improve the therapeutic results. (authors)

  13. Resolving runaway electron distributions in space, time, and energy

    Science.gov (United States)

    Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P.; Eidietis, N. W.; Lvovskiy, A.; Pace, D. C.; Brennan, D. P.; Hollmann, E. M.; Liu, C.; Moyer, R. A.; Shiraki, D.

    2018-05-01

    Areas of agreement and disagreement with present-day models of runaway electron (RE) evolution are revealed by measuring MeV-level bremsstrahlung radiation from runaway electrons (REs) with a pinhole camera. Spatially resolved measurements localize the RE beam, reveal energy-dependent RE transport, and can be used to perform full two-dimensional (energy and pitch-angle) inversions of the RE phase-space distribution. Energy-resolved measurements find qualitative agreement with modeling on the role of collisional and synchrotron damping in modifying the RE distribution shape. Measurements are consistent with predictions of phase-space attractors that accumulate REs, with non-monotonic features observed in the distribution. Temporally resolved measurements find qualitative agreement with modeling on the impact of collisional and synchrotron damping in varying the RE growth and decay rate. Anomalous RE loss is observed and found to be largest at low energy. Possible roles for kinetic instability or spatial transport to resolve these anomalies are discussed.

  14. CERN hosts Physics and Society Forum

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    On 28-29 March, CERN hosted the fifth edition of the European Physical Society's “Physics and Society” forum. The forum addresses the role of physicists in general society – be they in education, politics, industry or communication. This year, attendees looked at how physicists have adapted - and can continue to adapt - to work in the economic marketplace.   “The forums began back in 2006, as a special closing event for the 2005 World Year of Physics,” explains Martial Ducloy, former President of the French Physical Society and Chair of the EPS Forum Physics and Society. “We decided to keep the sessions going, as they gave physicists a venue to discuss the non-scientific issues that influence their daily work. As the world's largest international physics laboratory – and the venue for this year's EPS Council – CERN seemed the ideal place to host this year's forum.” The forum ...

  15. Electron drift time in silicon drift detectors: A technique for high precision measurement of electron drift mobility

    International Nuclear Information System (INIS)

    Castoldi, A.; Rehak, P.

    1995-01-01

    This paper presents a precise absolute measurement of the drift velocity and mobility of electrons in high resistivity silicon at room temperature. The electron velocity is obtained from the differential measurement of the drift time of an electron cloud in a silicon drift detector. The main features of the transport scheme of this class of detectors are: the high uniformity of the electron motion, the transport of the signal electrons entirely contained in the high-purity bulk, the low noise timing due to the very small anode capacitance (typical value 100 fF), and the possibility to measure different drift distances, up to the wafer diameter, in the same semiconductor sample. These features make the silicon drift detector an optimal device for high precision measurements of carrier drift properties. The electron drift velocity and mobility in a 10 kΩ cm NTD n-type silicon wafer have been measured as a function of the electric field in the range of possible operation of a typical drift detector (167--633 V/cm). The electron ohmic mobility is found to be 1394 cm 2 /V s. The measurement precision is better than 1%. copyright 1995 American Institute of Physics

  16. Development of Trust in an Online Breast Cancer Forum: A Qualitative Study.

    Science.gov (United States)

    Lovatt, Melanie; Bath, Peter A; Ellis, Julie

    2017-05-23

    Online health forums provide peer support for a range of medical conditions including life-threatening and terminal illnesses. Trust is an important component of peer-to-peer support, although relatively little is known about how trust forms within online health forums. The aim of this paper is to examine how trust develops and influences sharing among users of an online breast cancer forum. An interpretive qualitative approach was adopted. Data were collected from forum posts from 135 threads on 9 boards on the UK charity, Breast Cancer Care (BCC). Semistructured interviews were conducted with 14 BCC forum users. Both datasets were analyzed thematically using Braun and Clarke's approach and combined to triangulate analysis. Trust operates in 3 dimensions, structural, relational, and temporal, and these intersect with each other and do not operate in isolation. The structural dimension relates to how the affordances and formal rules of the site affected trust. The relational dimension refers to how trust was necessarily experienced in interactions with other forum users: it emerged within relationships and was a social phenomenon. The temporal dimension relates to how trust changed over time and was influenced by the length of time users spent on the forum. Trust is a process that changes over time and which is influenced by structural features of the forum, as well as informal but collectively understood relational interactions among forum users. The study provides a better understanding of how the intersecting structural, relational, and temporal aspects that support the development of trust facilitate sharing in online environments. These findings will help organizations developing online health forums. ©Melanie Lovatt, Peter A Bath, Julie Ellis. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.05.2017.

  17. European Stirling forum 2000. Proceedings; Europaeisches Stirling Forum 2000. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This document comprises all 42 papers presented at the 'European Stirling Forum 2000', held in Osnabrueck on February 22-24, 2000. Among others, the following subjects were discussed: Thermodynamics, new developments, Stirling engines, free piston heat pumps, flow optimisation of regenerators for Stirling engines, simulation for modelling of flow and heat transfer in the gas cycle of Stirling engines, design and performance, Stirling refrigerators, economic efficiency of biomass Stirling engines, power control of a Stirling CHP system, a Stirling refrigerator for ultralow temperatures in the refrigeration industry. [German] Das vorliegende Dokument enthaelt alle (42) Beitraege der Referenten des 'Europaeischen Stirling Forums 2000', das vom 22. bis 24. Februar 2000 in Osnabrueck stattgefunden hat. Einige der behandelten Themenschwerpunkte im Zusammenhang mit der Stirling-Maschine waren die Thermodynamik, neue Entwicklungen des Kreisprozesses, Heissgasmotoren, Freikolben-Waermepumpe, stroemungstechnische Optimierung von Regeneratoren fuer Stirling-Maschinen, Simulation zur Modellierung der Stroemung und Waermeuebertragung im Gaskreislauf von Stirling-Maschinen, Entwurf und Betriebsverhalten, Stirling-Kaeltemaschine, Wirtschaftlichkeit von Biomasse-Stirlingmotoren, Leistungsregelung eines Stirling-Blockheizkraftwerks, Anwendung eines Stirling-Kuehlers, zum Ultratiefkuehlen in der Kuehlindustrie. (AKF)

  18. Vibrational frequencies and dephasing times in excited electronic states by femtosecond time-resolved four-wave mixing

    Science.gov (United States)

    Joo, Taiha; Albrecht, A. C.

    1993-06-01

    Time-resolved degenerate four-wave mixing (TRDFWM) for an electronically resonant system in a phase-matching configuration that measures population decay is reported. Because the spectral width of input light exceeds the vibrational Bohr frequency of a strong Raman active mode, the vibrational coherence produces strong oscillations in the TRDFWM signal together with the usual population decay from the excited electronic state. The data are analyzed in terms of a four-level system: ground and excited electronic states each split by a vibrational quantum of a Raman active mode. Absolute frequencies and their dephasing times of the vibrational modes at ≈590 cm -1 are obtained for the excited as well as the ground electronic state. The vibrational dephasing rate in the excited electronic state is about an order of magnitude faster than that in the ground state, the origin of which is speculated upon.

  19. Time-Dependent Close-Coupling Methods for Electron-Atom/Molecule Scattering

    International Nuclear Information System (INIS)

    Colgan, James

    2014-01-01

    The time-dependent close-coupling (TDCC) method centers on an accurate representation of the interaction between two outgoing electrons moving in the presence of a Coulomb field. It has been extensively applied to many problems of electrons, photons, and ions scattering from light atomic targets. Theoretical Description: The TDCC method centers on a solution of the time-dependent Schrödinger equation for two interacting electrons. The advantages of a time-dependent approach are two-fold; one treats the electron-electron interaction essentially in an exact manner (within numerical accuracy) and a time-dependent approach avoids the difficult boundary condition encountered when two free electrons move in a Coulomb field (the classic three-body Coulomb problem). The TDCC method has been applied to many fundamental atomic collision processes, including photon-, electron- and ion-impact ionization of light atoms. For application to electron-impact ionization of atomic systems, one decomposes the two-electron wavefunction in a partial wave expansion and represents the subsequent two-electron radial wavefunctions on a numerical lattice. The number of partial waves required to converge the ionization process depends on the energy of the incoming electron wavepacket and on the ionization threshold of the target atom or ion.

  20. A Comparison of Response Rate, Response Time, and Costs of Mail and Electronic Surveys.

    Science.gov (United States)

    Shannon, David M.; Bradshaw, Carol C.

    2002-01-01

    Compared response rates, response time, and costs of mail and electronic surveys using a sample of 377 college faculty members. Mail surveys yielded a higher response rate and a lower rate of undeliverable surveys, but response time was longer and costs were higher than for electronic surveys. (SLD)

  1. DFT and time-resolved IR investigation of electron transfer between photogenerated 17- and 19-electron organometallic radicals

    Energy Technology Data Exchange (ETDEWEB)

    Cahoon, James B.; Kling, Matthias F.; Sawyer, Karma R.; Andersen, Lars K.; Harris, Charles B.

    2008-04-30

    The photochemical disproportionation mechanism of [CpW(CO){sub 3}]{sub 2} in the presence of Lewis bases PR{sub 3} was investigated on the nano- and microsecond time-scales with Step-Scan FTIR time-resolved infrared spectroscopy. 532 nm laser excitation was used to homolytically cleave the W-W bond, forming the 17-electron radicals CpW(CO){sub 3} and initiating the reaction. With the Lewis base PPh{sub 3}, disproportionation to form the ionic products CpW(CO){sub 3}PPh{sub 3}{sup +} and CpW(CO){sub 3}{sup -} was directly monitored on the microsecond time-scale. Detailed examination of the kinetics and concentration dependence of this reaction indicates that disproportionation proceeds by electron transfer from the 19-electron species CpW(CO){sub 3}PPh{sub 3} to the 17-electron species CpW(CO){sub 3}. This result is contrary to the currently accepted disproportionation mechanism which predicts electron transfer from the 19-electron species to the dimer [CpW(CO){sub 3}]{sub 2}. With the Lewis base P(OMe){sub 3} on the other hand, ligand substitution to form the product [CpW(CO){sub 2}P(OMe){sub 3}]{sub 2} is the primary reaction on the microsecond time-scale. Density Functional Theory (DFT) calculations support the experimental results and suggest that the differences in the reactivity between P(OMe){sub 3} and PPh{sub 3} are due to steric effects. The results indicate that radical-to-radical electron transfer is a previously unknown but important process for the formation of ionic products with the organometallic dimer [CpW(CO){sub 3}]{sub 2} and may also be applicable to the entire class of organometallic dimers containing a single metal-metal bond.

  2. The Time-Dependent Structure of the Electron Reconnection Layer

    Science.gov (United States)

    Hesse, Michael; Zenitani, Seiji; Kuznetsova, Masha; Klimas, Alex

    2009-01-01

    Collisionless magnetic reconnection is often associated with time-dependent behavior. Specifically, current layers in the diffusion region can become unstable to tearing-type instabilities on one hand, or to instabilities with current-aligned wave vectors on the other. In the former case, the growth of tearing instabilities typically leads to the production of magnetic islands, which potentially provide feedback on the reconnection process itself, as well as on the rate of reconnection. The second class of instabilities tend to modulate the current layer along the direction of the current flow, for instance generating kink-type perturbations, or smaller-scale turbulence with the potential to broaden the current layer. All of these processes contribute to rendering magnetic reconnection time-dependent. In this presentation, we will provide a summary of these effects, and a discussion of how much they contribute to the overall magnetic reconnection rate.

  3. Isotope effect on hydrated electron relaxation dynamics studied with time-resolved liquid jet photoelectron spectroscopy

    Science.gov (United States)

    Elkins, Madeline H.; Williams, Holly L.; Neumark, Daniel M.

    2016-05-01

    The excited state relaxation dynamics of the solvated electron in H2O and D2O are investigated using time-resolved photoelectron spectroscopy in a liquid microjet. The data show that the initial excited state decays on a time scale of 75 ± 12 fs in H2O and 102 ± 8 fs in D2O, followed by slower relaxation on time scales of 400 ± 70 fs and 390 ± 70 fs that are isotopically invariant within the precision of our measurements. Based on the time evolution of the transient signals, the faster and slower time constants are assigned to p → s internal conversion (IC) of the hydrated electron and relaxation on the ground electronic state, respectively. This assignment is consistent with the non-adiabatic mechanism for relaxation of the hydrated electron and yields an isotope effect of 1.4 ± 0.2 for IC of the hydrated electron.

  4. Electron-phonon thermalization in a scalable method for real-time quantum dynamics

    Science.gov (United States)

    Rizzi, Valerio; Todorov, Tchavdar N.; Kohanoff, Jorge J.; Correa, Alfredo A.

    2016-01-01

    We present a quantum simulation method that follows the dynamics of out-of-equilibrium many-body systems of electrons and oscillators in real time. Its cost is linear in the number of oscillators and it can probe time scales from attoseconds to hundreds of picoseconds. Contrary to Ehrenfest dynamics, it can thermalize starting from a variety of initial conditions, including electronic population inversion. While an electronic temperature can be defined in terms of a nonequilibrium entropy, a Fermi-Dirac distribution in general emerges only after thermalization. These results can be used to construct a kinetic model of electron-phonon equilibration based on the explicit quantum dynamics.

  5. Overview of the First Forum about Informal Science Education

    Science.gov (United States)

    Lebron Santos, Mayra; Pantoja, Carmen

    2018-01-01

    The First Forum on Informal Science Education was held at the University of Puerto Rico in 2015. This Forum had the following goals:1. Gather for the first time professionals dedicated to public communication and science outreach in Puerto Rico. 2. Exchange experiences and dissemination strategies with international professional science communicators.3. Encourage a fruitful dialogue between communicators with experience in museums, the media, and the integration of sciences with the arts.4. Encourage dialogue between communicators to facilitate future collaborations.The invited speakers came from Ibero-America and addressed aspects of science communication in museums and the media, the dissemination of science through the arts, the participation of universities in informal science education and the formal education of science communicators. The participants included museum specialists, journalists, artists, outreach specialists, formal educators interested in science outreach, and college students. During the Forum special events for the public were coordinated to celebrate the International Year of Light (2015). The exhibit “Light: Beyond the Bulb” was displayed. Dr. Julieta Fierro, recipient of the prestigious Kalinga Prize for the Popularization of Science awarded by UNESCO, presented the public talk “Light in the Universe”. Dr. Inés Rodríguez Hidalgo, director of the Science Museum of Valladolid, presented the talk "O Sole Mío: An Invitation to Solar Physics". We present an overview of the forum and some critical reflections on the topics discussed.

  6. The forum as a friend: parental mental illness and communication on open Internet forums.

    Science.gov (United States)

    Widemalm, My; Hjärthag, Fredrik

    2015-10-01

    The aim of this study was to identify how daughters or sons to parents suffering from mental illness perceive their situation. The objective was to provide new knowledge based on what they communicate on open Internet forums. The sample consisted of forum posts written by individuals who reported that they had mentally ill parents. Data collection comprised 301 comments from 35 forum threads on 5 different Swedish Internet forums, and predetermined inclusion criteria were used. Data were analyzed qualitatively using thematic analysis. The analysis generated four themes: "Caregiver burden," "Knowledge seeking," "Support from the forum," and "Frustration and powerlessness over health care." The results showed that parents' mental illness affected the forum writers on several levels, and they often felt stigmatized. The writers often lacked knowledge of their parents' mental illness and sought out Internet forums for information and support from peers in similar situations. The psychiatric care given to the parents was a source of dissatisfaction among the forum writers, who often felt that their parents did not receive adequate care. This study shows that fear of stigmatization and perceived lack of care and support caused forum writers to anonymously seek out Internet forums for information and support from others with similar experiences. The role of social support and the attractiveness of anonymity and availability typical for open Internet forums ought to be considered by health care professionals and researchers when developing new ways for providing support for children or adolescents with a mentally ill parent.

  7. Examining real-time time-dependent density functional theory nonequilibrium simulations for the calculation of electronic stopping power

    Science.gov (United States)

    Yost, Dillon C.; Yao, Yi; Kanai, Yosuke

    2017-09-01

    In ion irradiation processes, electronic stopping power describes the energy transfer rate from the irradiating ion to the target material's electrons. Due to the scarcity and significant uncertainties in experimental electronic stopping power data for materials beyond simple solids, there has been growing interest in the use of first-principles theory for calculating electronic stopping power. In recent years, advances in high-performance computing have opened the door to fully first-principles nonequilibrium simulations based on real-time time-dependent density functional theory (RT-TDDFT). While it has been demonstrated that the RT-TDDFT approach is capable of predicting electronic stopping power for a wide range of condensed matter systems, there has yet to be an exhaustive examination of the physical and numerical approximations involved and their effects on the calculated stopping power. We discuss the results of such a study for crystalline silicon with protons as irradiating ions. We examine the influences of key approximations in RT-TDDFT nonequilibrium simulations on the calculated electronic stopping power, including approximations related to basis sets, finite size effects, exchange-correlation approximation, pseudopotentials, and more. Finally, we propose a simple and efficient correction scheme to account for the contribution from core-electron excitations to the stopping power, as it was found to be significant for large proton velocities.

  8. High-performance electronics for time-of-flight PET systems

    International Nuclear Information System (INIS)

    Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

    2013-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr 3 crystals respectively.

  9. Electron and VLF travel time differences for wave-particle interactions at L=4: Pt. 2

    International Nuclear Information System (INIS)

    Rash, J.P.S.; Scourfield, M.W.J.; Dougherty, M.K.

    1984-01-01

    The cyclotron resonance or gyroresonance interaction has been widely invoked as a generation mechanism for discrete VLF emissions and plasmaspheric hiss. This interaction involves electrons and VLF waves travelling in opposite directions along a geomagnetic field line. We examine, for an interaction region in the equatorial plane at L=4, the energy of the resonant electrons as a function of VLF wave frequency and ambient equatorial electron density. Then for two different spatial configurations of the interaction and two standard plasma distribution models we examine the difference in travel times to a ground-based observer in the Southern hemisphere for the electrons and waves taking part in the interaction. This difference in travel times is shown as a function of VLF wave frequency and equatorial electron density. The results, and their significance for observations of auroral electrons and VLF at Sanae, Antarctica, are discussed and compared with similar results for the Cerenkov interaction discussed in an earlier paper

  10. Multicomponent Time-Dependent Density Functional Theory: Proton and Electron Excitation Energies.

    Science.gov (United States)

    Yang, Yang; Culpitt, Tanner; Hammes-Schiffer, Sharon

    2018-04-05

    The quantum mechanical treatment of both electrons and protons in the calculation of excited state properties is critical for describing nonadiabatic processes such as photoinduced proton-coupled electron transfer. Multicomponent density functional theory enables the consistent quantum mechanical treatment of more than one type of particle and has been implemented previously for studying ground state molecular properties within the nuclear-electronic orbital (NEO) framework, where all electrons and specified protons are treated quantum mechanically. To enable the study of excited state molecular properties, herein the linear response multicomponent time-dependent density functional theory (TDDFT) is derived and implemented within the NEO framework. Initial applications to FHF - and HCN illustrate that NEO-TDDFT provides accurate proton and electron excitation energies within a single calculation. As its computational cost is similar to that of conventional electronic TDDFT, the NEO-TDDFT approach is promising for diverse applications, particularly nonadiabatic proton transfer reactions, which may exhibit mixed electron-proton vibronic excitations.

  11. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  12. Out-of-ecliptic quiet time MeV electron increases: Ulysses COSPIN/KET observations

    International Nuclear Information System (INIS)

    Heber, B.; Ferreira, S.E.S.; Potgieter, M.S.; Henize, V.K.; Moeketsi, D.M.; Fichtner, H.; Kissmann, R.

    2004-01-01

    The propagation of cosmic rays in turbulent magnetic fields can be studied in detail by way of in-situ measurements of energetic particles in the three-dimensional heliosphere. Measurements of 3-20 MeV electrons from 1990 to 2003 have been made by the Kiel Electron Telescope (KET) onboard the Ulysses spacecraft during varying solar conditions. In order to interpret these measurements, it is necessary to distinguish between solar, galactic and Jovian electrons and to investigate their propagation, by using sophisticated particle propagation models. The solar contribution to the MeV electron intensities can be excluded by analyzing the electron energy spectra and the nuclei time histories. The residual electron intensities can be reasonably described by modulation models taking into account galactic cosmic rays as well as Jovian electrons using different diffusion coefficients for solar minimum and maximum. The way in which the relative contribution of Jovian (point source in the ecliptic) and galactic electrons (isotropic source) varies along the Ulysses orbit is strongly dependent on the choice of these coefficients. Since the 1970's quiet time electron increases have been observed in the ecliptic and interpreted as Jovian electron increases. Therefore, the occurrence of such quiet time electron increases is an indicator for a dominant Jovian contribution to the measured MeV electron intensities. At solar minimum and maximum such events have been observed up to ∼30 deg. and ∼45 deg. These observations are crucial for a determination of the diffusion parameters. At solar maximum a more efficient latitude transport is needed to account for the electron intensity variations

  13. Estimation of Nuclei Cooling Time by Electrons in Superdense Nonequilibrium Plasma

    CERN Document Server

    Kostenko, B F

    2004-01-01

    Estimations of nuclei cooling time by electrons in superdense nonequilibrium plasma formed at cavitation bubble collapse in deuterated acetone have been carried out. The necessity of these computations was stipulated by using in the latest theoretical calculations of nuclear reaction rate in these processes one poorly grounded assumption that electron temperatures remain essentially lower than nuclei ones during thermonuclear synthesis time t_s. The estimations have shown that the initial electron temperatures at the moment of superdense plasma formation with \\rho =100 g/cm^3 turn out to be appreciably lower than the nuclear temperatures, while the nuclei cooling time is of the same order as t_s.

  14. Time-resolved imaging of purely valence-electron dynamics during a chemical reaction

    DEFF Research Database (Denmark)

    Hockett, Paul; Bisgaard, Christer Z.; Clarkin, Owen J.

    2011-01-01

    Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems(1-6). By contrast, time-resolved structural-dynamics methods...... such as electron(7-10) or X-ray diffraction(11) and X-ray absorption(12) yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy(13-15) and high-harmonic generation(16......,17): in both cases, this sensitivity derives from the ionization-matrix element(18,19). Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during...

  15. FORUM OF POLITICAL PARTIES, THINK TANKS AND NON-GOVERNMENTAL ORGANIZATIONS OF THE BRICS GROUP

    Directory of Open Access Journals (Sweden)

    E. Gladun

    2017-01-01

    Full Text Available The Joint International Forum of Political Parties, Think Tanks and NonGovernmental Organizations of the BRICS took place in Fuzhou, China on 10–12 June 2017. The event was hosted jointly by the International Department of the Central Committee of the Communist Party of China, the China Council for BRICS Think Tank Cooperation and the China NGO Network for International Exchanges.For the first time in the story of BRICS cooperation the countries’ representatives witnessed the renewed format of the BRICS Academic Forum – two traditional tracks (academic conference and civil track were supplemented by the assembly of political parties. Taking its turn in chairing the multinational BRICS association in 2017, China proposed this new Forum format and joined together three dialogues that had grown out of the BRICS Academic Forum, which took place now for the ninth time.1 Another innovation on China’s part was the outreach format – representatives of 28 countries, including Indonesia, Malaysia, the Philippines, Cambodia, Egypt, Nigeria, Ethiopia, Kenya, Argentina, Chile and Mexico among others took part.The Joint International Forum was a truly large-scale international event – 37 political parties of 26 countries, 105 think tanks, and over 400 representatives of 79 civil society organizations were in attendance.2The Forum participants engaged in separate deliberations at the BRICS Academic Forum on “Pooling Wisdom and New Ideas for Cooperation,” the BRICS Civil Society Organizations Forum on “Stronger People-to-People Bond for Better Cooperation,” and the BRICS Political Parties Dialogue on the “Guiding Role of Political Parties in Promoting Cooperation.” The Forum was a complete success with broad consensus.

  16. Digital Discourse Markers in an ESL Learning Setting: The Case of Socialisation Forums

    Directory of Open Access Journals (Sweden)

    Alireza Shakarami

    2016-08-01

    Full Text Available Analysis of the linguistic discourse plays an important role in the social, cultural, ethnographic, and comparative studies of languages. Discourse markers as indispensable parts of this analysis are reportedly more common in informal speech than in written language. They could be used at different levels, i.e. as „linking words‟, „linking phrases‟, or „sentence connectors‟ to bind together pieces of a text like „glue‟. The objective of the study is to ascertain the discourse markers employed in synchronous online interactions and networking through constant comparison of discourse markers used in the discussion forums (DF with the discourse markers already reported in the literature. The study maintains discourse markers (DMs used in the formal written discourse in order to identify any probable pragmatic, or discoursal level differences in the DMs used in the two modes of writing (formal writing and typing in online communication. The findings indicate that the written language that students use in their electronic posts is to a great extent similar to that of the process view of writing. Specifically, the written language used in a digital socialisation forum is at times, monitored, reviewed, revised, and corrected by the students themselves and their peers.

  17. Wave function for time-dependent harmonically confined electrons in a time-dependent electric field.

    Science.gov (United States)

    Li, Yu-Qi; Pan, Xiao-Yin; Sahni, Viraht

    2013-09-21

    The many-body wave function of a system of interacting particles confined by a time-dependent harmonic potential and perturbed by a time-dependent spatially homogeneous electric field is derived via the Feynman path-integral method. The wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the Harmonic Potential Theorem wave function for the case of the time-independent harmonic confining potential.

  18. Understanding user intents in online health forums.

    Science.gov (United States)

    Zhang, Thomas; Cho, Jason H D; Zhai, Chengxiang

    2015-07-01

    Online health forums provide a convenient way for patients to obtain medical information and connect with physicians and peers outside of clinical settings. However, large quantities of unstructured and diversified content generated on these forums make it difficult for users to digest and extract useful information. Understanding user intents would enable forums to find and recommend relevant information to users by filtering out threads that do not match particular intents. In this paper, we derive a taxonomy of intents to capture user information needs in online health forums and propose novel pattern-based features for use with a multiclass support vector machine (SVM) classifier to classify original thread posts according to their underlying intents. Since no dataset existed for this task, we employ three annotators to manually label a dataset of 1192 HealthBoards posts spanning four forum topics. Experimental results show that a SVM using pattern-based features is highly capable of identifying user intents in forum posts, reaching a maximum precision of 75%, and that a SVM-based hierarchical classifier using both pattern and word features outperforms its SVM counterpart that uses only word features. Furthermore, comparable classification performance can be achieved by training and testing on posts from different forum topics.

  19. Radiation self-polarization of electrons moving in a magnetic field. [Vector spin operator, relaxation time

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V G; Dorofeev, O F; Sokolov, A A; Ternov, I M; Khalilov, V R [Moskovskij Gosudarstvennyj Univ. (USSR)

    1975-03-11

    When electrons move in a magnetic field, synchrotron radiation gives rise to transitions accompanied by the electron spin reorientation. In this case, it is essential that the transition probability depends on the spin orientation; as a result electron polarization takes place with the spin orientation being predominantly opposite to the direction of the magnetic field. This effect has been called ''radiative self-polarization of electrons''. The present work is concerned with the question how the choice of the spin operator will affect the self-polarization degree and relaxation time. The problem has been solved for a vector spin operator.

  20. Real-time measurement and monitoring of absorbed dose for electron beams

    Science.gov (United States)

    Korenev, Sergey; Korenev, Ivan; Rumega, Stanislav; Grossman, Leon

    2004-09-01

    The real-time method and system for measurement and monitoring of absorbed dose for industrial and research electron accelerators is considered in the report. The system was created on the basis of beam parameters method. The main concept of this method consists in the measurement of dissipated kinetic energy of electrons in the irradiated product, determination of number of electrons and mass of irradiated product in the same cell by following calculation of absorbed dose in the cell. The manual and automation systems for dose measurements are described. The systems are acceptable for all types of electron accelerators.

  1. Real-time measurement and monitoring of absorbed dose for electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Korenev, Sergey E-mail: sergey_korenev@steris.com; Korenev, Ivan; Rumega, Stanislav; Grossman, Leon

    2004-10-01

    The real-time method and system for measurement and monitoring of absorbed dose for industrial and research electron accelerators is considered in the report. The system was created on the basis of beam parameters method. The main concept of this method consists in the measurement of dissipated kinetic energy of electrons in the irradiated product, determination of number of electrons and mass of irradiated product in the same cell by following calculation of absorbed dose in the cell. The manual and automation systems for dose measurements are described. The systems are acceptable for all types of electron accelerators.

  2. Real-time measurement and monitoring of absorbed dose for electron beams

    International Nuclear Information System (INIS)

    Korenev, Sergey; Korenev, Ivan; Rumega, Stanislav; Grossman, Leon

    2004-01-01

    The real-time method and system for measurement and monitoring of absorbed dose for industrial and research electron accelerators is considered in the report. The system was created on the basis of beam parameters method. The main concept of this method consists in the measurement of dissipated kinetic energy of electrons in the irradiated product, determination of number of electrons and mass of irradiated product in the same cell by following calculation of absorbed dose in the cell. The manual and automation systems for dose measurements are described. The systems are acceptable for all types of electron accelerators

  3. In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope.

    Science.gov (United States)

    Hata, S; Miyazaki, S; Gondo, T; Kawamoto, K; Horii, N; Sato, K; Furukawa, H; Kudo, H; Miyazaki, H; Murayama, M

    2017-04-01

    This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. A Study of Electron Decay in Nitrogen Time After-glow

    International Nuclear Information System (INIS)

    Veis, P.; Coitout, H.; Magne, L.; Cernogora, G.

    1999-01-01

    This paper deals with electron density measurements in nitrogen time after-glow using hyper frequency resonant cavity. The studied pressures are from the range 9-530 Pa and discharge currents from 20 mA up to 500 mA. Electrons decreases up to the time of 1,4 ms in after-glow depending on pressure, pulse current and pulse duration (Authors)

  5. Prospects for quantitative and time-resolved double and continuous exposure off-axis electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Migunov, Vadim, E-mail: v.migunov@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Dwyer, Christian [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics, Arizona State University, Tempe, AZ 85287 (United States); Boothroyd, Chris B. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, viale B. Pichat 6/2, Bologna 40127 (Italy); Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2017-07-15

    The technique of double exposure electron holography, which is based on the superposition of two off-axis electron holograms, was originally introduced before the availability of digital image processing to allow differences between electron-optical phases encoded in two electron holograms to be visualised directly without the need for holographic reconstruction. Here, we review the original method and show how it can now be extended to permit quantitative studies of phase shifts that oscillate in time. We begin with a description of the theory of off-axis electron hologram formation for a time-dependent electron wave that results from the excitation of a specimen using an external stimulus with a square, sinusoidal, triangular or other temporal dependence. We refer to the more general method as continuous exposure electron holography, present preliminary experimental measurements and discuss how the technique can be used to image electrostatic potentials and magnetic fields during high frequency switching experiments. - Highlights: • Double and continuous exposure electron holography are described in detail. • The ability to perform quantitative studies of phase shifts that are oscillating in time is illustrated. • Theoretical considerations related to noise are presented. • Future high frequency electromagnetic switching experiments are proposed.

  6. Suisse Romande forum meets at CERN

    CERN Multimedia

    2005-01-01

    The subject of the «Forum des 100» meeting held at CERN on 9 June was «Suisse Romande: Une région en quête de succès» (a region in search of success). Organised by the magazine l'Hebdo and the Rezonance.ch association, the forum was attended by numerous representatives from politics, industry and education and consisted of a day of lectures and debates. Pascal Couchepin, Head of the Swiss Federal Department of Home Affairs, and Luc Ferry, philosopher and former French Education Minister, were among those who took part in the forum.

  7. The South African Forum for Radiation Protection

    International Nuclear Information System (INIS)

    Basson, J.K.; Le Roux, P.R.

    1993-01-01

    The use of ionising radiation in South Africa since the turn of the century was initially limited to x-rays and radium, with predominant applications in medicine for diagnosis and therapy. Since 1948 artificial radio-isotopes have been increasingly available and such applications have been widely extended to industry, agriculture and science. Initially, the Council for Scientific and Industrial Research developed radiation protection in South Africa. It was later recommended that an independent forum, the South African Forum for Radiation Protection, be established. The activities of the Forum are described

  8. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: Thérèse Wolf, Secretary of Forum Engelberg; Alain Hervé; Horst Wenninger; and Alexander Höchli, Forum member and former Landammann of the canton of Obwalden, at the CMS detector's assembly site.

  9. Observing electron localization in a dissociating H2+ molecule in real time.

    Science.gov (United States)

    Xu, H; Li, Zhichao; He, Feng; Wang, X; Atia-Tul-Noor, A; Kielpinski, D; Sang, R T; Litvinyuk, I V

    2017-06-16

    Dissociation of diatomic molecules with odd number of electrons always causes the unpaired electron to localize on one of the two resulting atomic fragments. In the simplest diatomic molecule H 2 + dissociation yields a hydrogen atom and a proton with the sole electron ending up on one of the two nuclei. That is equivalent to breaking of a chemical bond-the most fundamental chemical process. Here we observe such electron localization in real time by performing a pump-probe experiment. We demonstrate that in H 2 + electron localization is complete in just 15 fs when the molecule's internuclear distance reaches 8 atomic units. The measurement is supported by a theoretical simulation based on numerical solution of the time-dependent Schrödinger equation. This observation advances our understanding of detailed dynamics of molecular dissociation.

  10. Real-Time Robust Adaptive Modeling and Scheduling for an Electronic Commerce Server

    Science.gov (United States)

    Du, Bing; Ruan, Chun

    With the increasing importance and pervasiveness of Internet services, it is becoming a challenge for the proliferation of electronic commerce services to provide performance guarantees under extreme overload. This paper describes a real-time optimization modeling and scheduling approach for performance guarantee of electronic commerce servers. We show that an electronic commerce server may be simulated as a multi-tank system. A robust adaptive server model is subject to unknown additive load disturbances and uncertain model matching. Overload control techniques are based on adaptive admission control to achieve timing guarantees. We evaluate the performance of the model using a complex simulation that is subjected to varying model parameters and massive overload.

  11. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    International Nuclear Information System (INIS)

    Hugenschmidt, Christoph; Legl, Stefan

    2006-01-01

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1 eV at high electron energies up to E≅1000 eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube

  12. Nonadiabatic Dynamics in Single-Electron Tunneling Devices with Time-Dependent Density-Functional Theory

    Science.gov (United States)

    Dittmann, Niklas; Splettstoesser, Janine; Helbig, Nicole

    2018-04-01

    We simulate the dynamics of a single-electron source, modeled as a quantum dot with on-site Coulomb interaction and tunnel coupling to an adjacent lead in time-dependent density-functional theory. Based on this system, we develop a time-nonlocal exchange-correlation potential by exploiting analogies with quantum-transport theory. The time nonlocality manifests itself in a dynamical potential step. We explicitly link the time evolution of the dynamical step to physical relaxation timescales of the electron dynamics. Finally, we discuss prospects for simulations of larger mesoscopic systems.

  13. Electronic School.

    Science.gov (United States)

    Executive Educator, 1994

    1994-01-01

    This issue of "The Electronic School" features a special forum on computer networking. Articles specifically focus on network operating systems, cabling requirements, and network architecture. Tom Wall argues that virtual reality is not yet ready for classroom use. B.J. Novitsky profiles two high schools experimenting with CD-ROM…

  14. Storm-time radiation belt electron dynamics: Repeatability in the outer radiation belt

    Science.gov (United States)

    Murphy, K. R.; Mann, I. R.; Rae, J.; Watt, C.; Boyd, A. J.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.

    2017-12-01

    During intervals of enhanced solar wind driving the outer radiation belt becomes extremely dynamic leading to geomagnetic storms. During these storms the flux of energetic electrons can vary by over 4 orders of magnitude. Despite recent advances in understanding the nature of competing storm-time electron loss and acceleration processes the dynamic behavior of the outer radiation belt remains poorly understood; the outer radiation belt can exhibit either no change, an enhancement, or depletion in radiation belt electrons. Using a new analysis of the total radiation belt electron content, calculated from the Van Allen probes phase space density (PSD), we statistically analyze the time-dependent and global response of the outer radiation belt during storms. We demonstrate that by removing adiabatic effects there is a clear and repeatable sequence of events in storm-time radiation belt electron dynamics. Namely, the relativistic (μ=1000 MeV/G) and ultra-relativistic (μ=4000 MeV/G) electron populations can be separated into two phases; an initial phase dominated by loss followed by a second phase dominated by acceleration. At lower energies, the radiation belt seed population of electrons (μ=150 MeV/G) shows no evidence of loss but rather a net enhancement during storms. Further, we investigate the dependence of electron dynamics as a function of the second adiabatic invariant, K. These results demonstrate a global coherency in the dynamics of the source, relativistic and ultra-relativistic electron populations as function of the second adiabatic invariant K. This analysis demonstrates two key aspects of storm-time radiation belt electron dynamics. First, the radiation belt responds repeatably to solar wind driving during geomagnetic storms. Second, the response of the radiation belt is energy dependent, relativistic electrons behaving differently than lower energy seed electrons. These results have important implications in radiation belt research. In particular

  15. Electronic Media Use and Sleep Among Preschoolers: Evidence for Time-Shifted and Less Consolidated Sleep.

    Science.gov (United States)

    Beyens, Ine; Nathanson, Amy I

    2018-01-11

    This study examined the association between electronic media use and sleep among preschoolers, using a national sample of 402 mothers of 3- to 5-year-olds. Participants completed an online survey assessing preschoolers' electronic media use, bedtime and wake time, sleep time, napping behaviors, and sleep consolidation. Results showed that heavier television use and tablet use, both overall and in the evening, were associated with later bedtimes and later wake times, but not with fewer hours of sleep, providing evidence for a time-shifting process. In addition, heavier daily television use and evening smartphone use were associated with increased daytime napping. Moreover, heavier daily television use, daily and evening smartphone use, and evening tablet use were associated with poorer sleep consolidation, suggesting less mature sleep patterns. These findings indicate that media effects on the timing of sleep and the proportion of sleep that occurs at night are important to consider when assessing the health risks of electronic media on children.

  16. Measurements of secondary electron cross sections by the pulsed electron beam time-of-flight method. I. Molecular nitrogen

    International Nuclear Information System (INIS)

    Goruganthu, R.R.; Wilson, W.G.; Bonham, R.A.

    1983-01-01

    The secondary electron cross sections for gaseous molecular nitrogen are reported at ejection angles of 30, 45, 60, 75, 90, 105, 120, 135 and 150 0 , for the energy range 1.5 eV to 20 eV and incident electron energy of 1 keV. The pulsed electron beam time-of-flight methd was employed. The results were placed on an absolute scale by normalization to the elastic scattering. They were compared, where possible, with those reported by Opal, Beaty, and Peterson (OBP). The agreement is somewhat better when the OBP data are divided by 0.53 + 0.47 sintheta as suggested by Rudd and DuBois. Fits of our data by Legendre-polynomial expansions are used to estimate the low-energy portion of the cross-section, dsigma/dE. This work suggests that existing experimental cross sections for secondary electron ejection as a function of angle and ejected energy may be no better known than +-40%, especially in the low energy region. 7 references, 14 figures, 2 tables

  17. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    Sternwheeler, W.D.E.

    1992-01-01

    This paper provides highlights from the 1992 winter meeting of the Low Level Radioactive Wastes Forum. Topics of discussion included: legal information; state and compact reports; freedom of information requests; and storage

  18. Titaanide heitlus: Forum Cinemas vs Cinamon

    Index Scriptorium Estoniae

    2009-01-01

    Cinamon Group avab Solarise keskuses uue Cinamoni kinoketti kuuluva kino, mis konkureerib Coca-Cola Plazaga (võrdlev tabel, allikad: Cinamoni turundusjuht Evelyn Laar ja Forum Cinemas' levijuhi asetäitja Timo Diener)

  19. International Ecohealth Forum 2008 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... the International Forum on Ecosystem Approaches to Human Health (Montreal, ... the International Association of Ecology and Health (IAEH), and a Brazilian ... Nutrition, health policy, and ethics in the age of public-private partnerships.

  20. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrive Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: CERN Director-General Prof. Luciano Maiani (left) speaks to Forum members and public figures from the Geneva area during the visit. In the background is Jean-Claude Landry from the Department of the Interior, Agriculture and Environment, State of Geneva. Photo 02: CERN Director-General Prof. Luciano Maiani (left) speaks to Forum members and public figures from the Geneva area during the visit. In the background is Bernard Ecoffey, Founder of the Forum Engelberg.

  1. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1992-01-01

    This paper provides highlights from the summer meeting of the Low Level Radioactive Waste Forum. Topics of discussion included: responsibility for nonfuel component disposal; state experiences in facility licensing; and volume projections

  2. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1992-01-01

    This report provides highlights from the 1992 fall meeting of the Low LEvel Radioactive Waste Forum. Topics included: disposal options after 1992; interregional agreements; management alternatives; policy; and storage

  3. Competition, Regulation and Development Research Forum ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... Forum : Competition and Regulatory Implementation Issues in Developing Countries ... create challenges that influence the operation of regulatory institutions. ... IWRA/IDRC webinar on climate change and adaptive water management.

  4. Time-dependent quantum chemistry of laser driven many-electron molecules

    International Nuclear Information System (INIS)

    Nguyen-Dang, Thanh-Tung; Couture-Bienvenue, Étienne; Viau-Trudel, Jérémy; Sainjon, Amaury

    2014-01-01

    A Time-Dependent Configuration Interaction approach using multiple Feshbach partitionings, corresponding to multiple ionization stages of a laser-driven molecule, has recently been proposed [T.-T. Nguyen-Dang and J. Viau-Trudel, J. Chem. Phys. 139, 244102 (2013)]. To complete this development toward a fully ab-initio method for the calculation of time-dependent electronic wavefunctions of an N-electron molecule, we describe how tools of multiconfiguration quantum chemistry such as the management of the configuration expansion space using Graphical Unitary Group Approach concepts can be profitably adapted to the new context, that of time-resolved electronic dynamics, as opposed to stationary electronic structure. The method is applied to calculate the detailed, sub-cycle electronic dynamics of BeH 2 , treated in a 3–21G bound-orbital basis augmented by a set of orthogonalized plane-waves representing continuum-type orbitals, including its ionization under an intense λ = 800 nm or λ = 80 nm continuous-wave laser field. The dynamics is strongly non-linear at the field-intensity considered (I ≃ 10 15 W/cm 2 ), featuring important ionization of an inner-shell electron and strong post-ionization bound-electron dynamics

  5. Simulations of the temporal and spatial resolution for a compact time-resolved electron diffractometer

    Science.gov (United States)

    Robinson, Matthew S.; Lane, Paul D.; Wann, Derek A.

    2016-02-01

    A novel compact electron gun for use in time-resolved gas electron diffraction experiments has recently been designed and commissioned. In this paper we present and discuss the extensive simulations that were performed to underpin the design in terms of the spatial and temporal qualities of the pulsed electron beam created by the ionisation of a gold photocathode using a femtosecond laser. The response of the electron pulses to a solenoid lens used to focus the electron beam has also been studied. The simulated results show that focussing the electron beam affects the overall spatial and temporal resolution of the experiment in a variety of ways, and that factors that improve the resolution of one parameter can often have a negative effect on the other. A balance must, therefore, be achieved between spatial and temporal resolution. The optimal experimental time resolution for the apparatus is predicted to be 416 fs for studies of gas-phase species, while the predicted spatial resolution of better than 2 nm-1 compares well with traditional time-averaged electron diffraction set-ups.

  6. Time delay for resonant vibrational excitation in electron--molecule collisions

    International Nuclear Information System (INIS)

    Gauyacq, J.P.

    1990-01-01

    An analysis of the time delay associated with vibrational excitation in electron--molecule collision is presented. It consists of a direct study of the time dependence of the process for three model systems. An electron wave packet, that is narrow in time, is sent on the target and the amplitudes in the different inelastic channels are studied as functions of time. The time delay is found to correspond to very different time effects: broadenings, shifts in time of the wave packet, but also complex distortions that cannot be represented by a time delay. The direct analysis of the scattered wave also provides new insights into the vibrational excitation process. It should be a useful tool to analyze complex collision processes

  7. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. He is seen here (right) in discussion with Bernard Ecoffey, Founder of the Forum Engelberg.

  8. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. He is pictured here (right) alongside CERN Director-General Prof. Luciano Maiani during the visit of Forum members to CERN.

  9. The Copenhagen Forum 1996-2016

    DEFF Research Database (Denmark)

    Ry Nielsen, Jens Carl; Raine, John

    2016-01-01

    Purpose: This chapter tells the story of the initiation, development (over two decades) and collective contribution of the Copenhagen Forum since its foundation in 1996. This Forum comprises a grouping of teachers and directors of masters-level public administrative programmes (notably the MPA) f...... the inspiration for this volume, and the individual contributions, derive. It is a context that has been all about a shared fascination with, and collective commitment to, the advancement of learning and development among practicing public managers....

  10. Timing characteristics of the VEhU-6 microchannel electron multipliers

    International Nuclear Information System (INIS)

    Bakhtizin, R.Z.; Yumaguzin, Yu.M.

    1982-01-01

    The VEhU-6 charnel electron multiplier timing characteristics are experimentally studied. Dependence of monoelectron pulse duration at the VEhU-6 output at different values of channel supply voltage is investigated. The VEhU-6 delay time is measured. Delay time increased from 10 to 30 ns with the increase of channel supply voltage from 2.8 to 3.2 kV (at approximately 10 5 pulse/s loading). Delay time increases with loading decrease

  11. Shielded button electrodes for time-resolved measurements of electron cloud buildup

    International Nuclear Information System (INIS)

    Crittenden, J.A.; Billing, M.G.; Li, Y.; Palmer, M.A.; Sikora, J.P.

    2014-01-01

    We report on the design, deployment and signal analysis for shielded button electrodes sensitive to electron cloud buildup at the Cornell Electron Storage Ring. These simple detectors, derived from a beam-position monitor electrode design, have provided detailed information on the physical processes underlying the local production and the lifetime of electron densities in the storage ring. Digitizing oscilloscopes are used to record electron fluxes incident on the vacuum chamber wall in 1024 time steps of 100 ps or more. The fine time steps provide a detailed characterization of the cloud, allowing the independent estimation of processes contributing on differing time scales and providing sensitivity to the characteristic kinetic energies of the electrons making up the cloud. By varying the spacing and population of electron and positron beam bunches, we map the time development of the various cloud production and re-absorption processes. The excellent reproducibility of the measurements also permits the measurement of long-term conditioning of vacuum chamber surfaces

  12. First Detection of Low Energy Electron Neutrinos in Liquid Argon Time Projection Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Corey James [Yale U.

    2016-01-01

    Electron neutrino appearance is the signature channel to address the most pressing questions in neutrino oscillations physics, at both long and short baselines. This includes the search for CP violation in the neutrino sector, which the U.S. flagship neutrino experiment DUNE will address. In addition, the Short Baseline Neutrino Program at Fermilab (MicroBooNE, SBND, ICARUS-T600) searches for new physics, such as sterile neutrinos, through electron neutrino appearance. Liquid argon time projection chambers are the forefront of neutrino detection technology, and the detector of choice for both short and long baseline neutrino oscillation experiments. This work presents the first experimental observation and study of electron neutrinos in the 1-10 GeV range, the essential oscillation energy regime for the above experiments. The systematic uncertainties for an electron neutrino appearance search for the Fermilab Short Baseline Neutrino Program are carefully quantified, and the characterization of separation between electrons and high energy photons is examined.

  13. All-optical time-resolved measurement of laser energy modulation in a relativistic electron beam

    Directory of Open Access Journals (Sweden)

    D. Xiang

    2011-11-01

    Full Text Available We propose and demonstrate an all-optical method to measure laser energy modulation in a relativistic electron beam. In this scheme the time-dependent energy modulation generated from the electron-laser interaction in an undulator is converted into time-dependent density modulation with a chicane, which is measured to infer the laser energy modulation. The method, in principle, is capable of simultaneously providing information on femtosecond time scale and 10^{-5} energy scale not accessible with conventional methods. We anticipate that this method may have wide applications in many laser-based advanced beam manipulation techniques.

  14. Lyapunov-based constrained engine torque control using electronic throttle and variable cam timing

    NARCIS (Netherlands)

    Feru, E.; Lazar, M.; Gielen, R.H.; Kolmanovsky, I.V.; Di Cairano, S.

    2012-01-01

    In this paper, predictive control of a spark ignition engine equipped with an electronic throttle and a variable cam timing actuator is considered. The objective is to adjust the throttle angle and the engine cam timing in order to reduce the exhaust gas emissions while maintaining fast and

  15. Time-lapse misorientation maps for the analysis of electron backscatter diffraction data from evolving microstructures

    NARCIS (Netherlands)

    Wheeler, J.; Cross, A.; Drury, M.; Hough, R.M.; Mariani, E.; Piazolo, S.; Prior, D.J.

    2011-01-01

    A “time-lapse misorientation map” is defined here as a map which shows the orientation change at each point in an evolving crystalline microstructure between two different times. Electron backscatter diffraction data from in situ heating experiments can be used to produce such maps, which then

  16. Electron Spin Coherence Times in Si/SiGe Quantum Dots

    Science.gov (United States)

    Jock, R. M.; He, Jianhua; Tyryshkin, A. M.; Lyon, S. A.; Lee, C.-H.; Huang, S.-H.; Liu, C. W.

    2014-03-01

    Single electron spin states in silicon have shown a great deal of promise as qubits due to their long spin relaxation (T1) and coherence (T2) times. Recent results exhibit a T2 of 250 us for electrons confined in Si/SiGe quantum dots at 350 mK. These experiments used conventional X-band (10 GHz) pulsed Electron Spin Resonance on a large area (3.5 mm x 20 mm), dual-gated, undoped Si/SiGe heterostructure quantum dots. These dots are induced in a natural Si quantum well by e-beam defined gates having a lithographic radius of 150 nm and pitch of 700 nm. The relatively large size of these dots led to closely spaced energy levels and long T2's could only be measured at sub-Kelvin temperatures. At 2K confined electrons displayed a 3 us T2, which is comparable to that of 2D electrons at that temperature. Decreasing the quantum dot size increases the electron confinement and reduces the effects of valley-splitting and spin-orbit coupling on the electron spin coherence times. We will report results on dots with 80 nm lithographic radii and a 375 nm pitch. This device displays an extended electron coherence time of 30 us at 2K, suggesting tighter confinement of electrons. Further measurements at lower temperatures are in progress. This work was supported in part by NSF through the Materials World Network program (DMR-1107606) and the Princeton MRSEC (DMR-0819860), and in part by the U.S. Army Research Office (W911NF-13-1-0179).

  17. Efficient scattering of electrons below few keV by Time Domain Structures around injection fronts

    Science.gov (United States)

    Vasko, I.; Agapitov, O. V.; Mozer, F.; Artemyev, A.; Krasnoselskikh, V.

    2016-12-01

    Van Allen Probes observations show an abundance of non-linear large-amplitude electrostatic spikes around injection fronts in the outer radiation belt. These spikes referred to as Time Domain Structures (TDS) include electron holes, double layers and more complicated solitary waves. The electron scattering driven by TDS may not be evaluated via the standard quasi-linear theory, since TDS are in principle non-linear plasma modes. In this paper we analyze the scattering of electrons by three-dimensional TDS (with non-negligible perpendicular electric field) around injection fronts. We derive the analytical formulas describing the local scattering by single TDS and show that the most efficiently scattered electrons are those in the first cyclotron resonance (electrons crossing TDS on a time scale comparable with their gyroperiod). The analytical formulas are verified via the test-particle simulation. We compute the bounce-averaged diffusion coefficients and demonstrate their dependence on the TDS spatial distribution, individual TDS parameters and L shell. We show that TDS are able to provide the pitch-angle scattering of <5 keV electrons at rate 10-2-10-4 s-1 and, thus, can be responsible for driving loss of electrons out of injections fronts on a time scale from few minutes to few hours. TDS can be, thus, responsible for driving diffuse aurora precipitations conjugated to injection fronts. We show that the pitch-angle scattering rates driven by TDS are comparable with those due to chorus waves and exceed those due to electron cyclotron harmonics. For injections fronts with no significant wave activity in the frequency range corresponding to chorus waves, TDS can be even dominant mechanism for losses of below few keV electrons.

  18. Electron localisation in static and time-dependent one-dimensional model systems

    Science.gov (United States)

    Durrant, T. R.; Hodgson, M. J. P.; Ramsden, J. D.; Godby, R. W.

    2018-02-01

    The most direct signature of electron localisation is the tendency of an electron in a many-body system to exclude other same-spin electrons from its vicinity. By applying this concept directly to the exact many-body wavefunction, we find that localisation can vary considerably between different ground-state systems, and can also be strongly disrupted, as a function of time, when a system is driven by an applied electric field. We use this measure to assess the well-known electron localisation function (ELF), both in its approximate single-particle form (often applied within density-functional theory) and its full many-particle form. The full ELF always gives an excellent description of localisation, but the approximate ELF fails in time-dependent situations, even when the exact Kohn-Sham orbitals are employed.

  19. Nonadiabatic Dynamics May Be Probed through Electronic Coherence in Time-Resolved Photoelectron Spectroscopy.

    Science.gov (United States)

    Bennett, Kochise; Kowalewski, Markus; Mukamel, Shaul

    2016-02-09

    We present a hierarchy of Fermi golden rules (FGRs) that incorporate strongly coupled electronic/nuclear dynamics in time-resolved photoelectron spectroscopy (TRPES) signals at different levels of theory. Expansion in the joint electronic and nuclear eigenbasis yields the numerically most challenging exact FGR (eFGR). The quasistatic Fermi Golden Rule (qsFGR) neglects nuclear motion during the photoionization process but takes into account electronic coherences as well as populations initially present in the pumped matter as well as those generated internally by coupling between electronic surfaces. The standard semiclassical Fermi Golden Rule (scFGR) neglects the electronic coherences and the nuclear kinetic energy during the ionizing pulse altogether, yielding the classical Condon approximation. The coherence contributions depend on the phase-profile of the ionizing field, allowing coherent control of TRPES signals. The photoelectron spectrum from model systems is simulated using these three levels of theory. The eFGR and the qsFGR show temporal oscillations originating from the electronic or vibrational coherences generated as the nuclear wave packet traverses a conical intersection. These oscillations, which are missed by the scFGR, directly reveal the time-evolving splitting between electronic states of the neutral molecule in the curve-crossing regime.

  20. On some practical consideration of the electron beam breakup transit time oscillator

    International Nuclear Information System (INIS)

    Kwan, T.J.T.

    1992-01-01

    The electron beam breakup transit time oscillator (BTO) makes use of the interaction between an electron beam and the azimuthally azimuthally asymmetric transverse magnetic mode (TM 110 ) of a cavity to facilitate the exchange of energy between them. Linear theory has shown a large growth rate in the regime where space-charge effects can be ignored. In this study, we have investigated the non-ideal elements in the BTO and evaluated their effects accordingly. The practical issues under consideration are electron beam quality, energy, and space-charge potential. Our calculations indicate only a modest unfavorable scalings with respect to these parameters

  1. Identification of Low Momentum Electrons in The Time Projection Chamber of The ALICE Detector.

    CERN Document Server

    Mwewa, Chilufya

    2013-01-01

    This paper presents results obtained in the study to identify noisy low momentum electrons in the Time Projection Chamber (TPC) of the ALICE detector. To do this, the Circle Hough Transform is employed under the openCV library in python programming. This is tested on simulated tracks in the transverse view of the TPC. It is found that the noisy low momentum electrons can be identified and their exact positions in the transverse plane can be obtained.

  2. Isotope effect on hydrated electron relaxation dynamics studied with time-resolved liquid jet photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Elkins, Madeline H.; Williams, Holly L. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Neumark, Daniel M., E-mail: dneumark@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-05-14

    The excited state relaxation dynamics of the solvated electron in H{sub 2}O and D{sub 2}O are investigated using time-resolved photoelectron spectroscopy in a liquid microjet. The data show that the initial excited state decays on a time scale of 75 ± 12 fs in H{sub 2}O and 102 ± 8 fs in D{sub 2}O, followed by slower relaxation on time scales of 400 ± 70 fs and 390 ± 70 fs that are isotopically invariant within the precision of our measurements. Based on the time evolution of the transient signals, the faster and slower time constants are assigned to p → s internal conversion (IC) of the hydrated electron and relaxation on the ground electronic state, respectively. This assignment is consistent with the non-adiabatic mechanism for relaxation of the hydrated electron and yields an isotope effect of 1.4 ± 0.2 for IC of the hydrated electron.

  3. 7. heat pump forum. Lectures; 7. Forum Waermepumpe. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the 7th heat pump forum of the German Federal Association for heat pumps e.V. (Berlin, Federal Republic of Germany) between 22nd and 23rd March, 2009, at the Ellington Hotel in Berlin, the following lectures were held: (1) Potentials of the near-surface geothermics in Germany (H. Gassner); (2) Significance of renewable energy sources after the Bundestag election (D. Schuetz); (3) European draft laws in survey: EE regulation, EPBD, EuP (M. Ferber); (4) My personal experiences with heat pumps (G. Nuesslein); (5) European energy policy with relevance to the German heating market (A. Luecke); (6) Do we economize sustainable? - Reactions of companies on the challenge of a sustainable development (C. Berg); (7) Utilize the crisis now - the economic chances of a sustainable energy supply (C. Kemfert); (8) EE regulation: Status quo. Report of the National Renewable Eneregy Action Plan (NREAP) (K. Freier); (9) A legal evaluation of the EE regulation for the energy market (T. Mueller); (10) MAP funding guidelines (U. Sattler); (11) Utilization of renewable energies for heat generation - Experiences of the housing industry (I. Vogler); (12) Combination o the central near-heat supply and decentral drinking water heating in multi-storey new buildings (M.-J. Mucke); (13) Eddicient contracting for heat pumps (A. Kaemmerer); (14) Eco-Design - EU-guidelines and their effects on the heat pump (M. Roffe-Vidal); (15) The quality seal for heat pumps in the Swiss promotion policy (R. Phillips); (16) Enhancement of the significance of the EHPA quality seal in Europe (K. Ochsner); (17) Chances and benefit of export initiatives for the heat pump industry (C. Wittig); (18) The heat pump market in Ireland (P. Murphy); (19) Quantum heat pumps in double capacitors (M. Enzensperger); (20) First CO{sub 2}-free football stadium worldwide thanks to heat pumps (A. Poehlmann); (21) The heat pump in turnkey solid-construction house (C. Schmidt); (22) Instruments of quality requirement and

  4. Effects of electronic emergency-department whiteboards on clinicians' time distribution and mental workload

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2016-01-01

    Whiteboards are a central tool at emergency departments. We investigate how the substitution of electronic for dry-erase whiteboards affects emergency department clinicians’ mental workload and distribution of their time. With the electronic whiteboard, physicians and nurses spend more...... of their time in the work areas where other clinicians are present and whiteboard information is permanently displayed, and less in the patient rooms. Main reasons for these changes appear to be that the electronic whiteboard facilitates better timeouts and handovers. Physicians and nurses are, however......, in the patient rooms for longer periods at a time, suggesting a more focused patient contact. The physicians’ mental workload has increased during timeouts, whereas the nurses’ mental workload has decreased at the start of shifts when they form an overview of the emergency department. Finally, the secretaries...

  5. Time-resolved protein nano-crystallography using an X-ray free-electron laser

    International Nuclear Information System (INIS)

    Aquila, Andrew; Hunter, Mark S.; Fromme, Petra; Fromme, Raimund; Grotjohann, Ingo; Doak, R. Bruce; Kirian, Richard A.; Schmidt, Kevin E.; Wang, Xiaoyu; Weierstall, Uwe; Spence, John C.H.; White, Thomas A.; Caleman, Carl; DePonte, Daniel P.; Fleckenstein, Holger; Gumprecht, Lars; Liang, Mengning; Martin, Andrew V.; Schulz, Joachim; Stellato, Francesco; Stern, Stephan; Barty, Anton; Andreasson, Jakob; Davidsson, Jan; Hajdu, Janos; Maia, Filipe R.N.C.; Seibert, M. Marvin; Timneanu, Nicusor; Arnlund, David; Johansson, Linda; Malmerberg, Erik; Neutze, Richard; Bajt, Sasa; Barthelmess, Miriam; Graafsma, Heinz; Hirsemann, Helmut; Wunderer, Cornelia; Barends, Thomas R.M.; Foucar, Lutz; Krasniqi, Faton; Lomb, Lukas; Rolles, Daniel; Schlichting, Ilme; Schmidt, Carlo; Bogan, Michael J.; Hampton, Christina Y.; Sierra, Raymond; Starodub, Dmitri; Bostedt, Christoph; Bozek, John D.; Messerschmidt, Marc; Williams, Garth J.; Bottin, Herve

    2012-01-01

    We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photo-activated states of large membrane protein complexes in the form of nano-crystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 μs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems. (authors)

  6. The implementation of real-time plasma electron density calculations on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.C., E-mail: zzc@ipp.ac.cn; Xiao, B.J.; Wang, F.; Liu, H.Q.; Yuan, Q.P.; Wang, Y.; Yang, Y.

    2016-11-15

    Highlights: • The real-time density calculation system (DCS) has been applied to the EAST 3-wave polarimeter-interferometer (POINT) system. • The new system based on Flex RIO acquires data at high speed and processes them in a short time. • Roll-over module is developed for density calculation. - Abstract: The plasma electron density is one of the most fundamental parameters in tokamak experiment. It is widely used in the plasma control system (PCS) real-time control, as well as plasma physics analysis. The 3-wave polarimeter-interferometer (POINT) system had been used to measure the plasma electron density on the EAST since last campaign. This paper will give the way to realize the real-time measurement of plasma electron density. All intermediate frequency (IF) signals after POINT system, in the 0.5–3 MHz range, stream to the real-time density calculation system (DCS) to extract the phase shift information. All the prototype hardware is based on NI Flex RIO device which contains a high speed Field Programmable Gate Array (FPGA). The original signals are sampled at 10 M Samples/s, and the data after roll-over module are transmitted to PCS by reflective memory (RFM). With this method, real-time plasma electron density data with high accuracy and low noise had been obtained in the latest EAST tokamak experiment.

  7. Generation IV international forum 2002 - remarks

    International Nuclear Information System (INIS)

    Abraham, S.

    2002-01-01

    Analyses and forecasts underscore the important role of nuclear power in energy supply in the 21st century. Important aspects in this respect are the conservation of fossil resources, the protection of the world's climate, and the continuity of supply. Present 1st and 2nd generation nuclear power plants ensure an economical and technically mature electricity supply. Advanced systems offering, e.g., higher efficiency of fuel utilization, simplified systems technology, and advanced safety characteristics, can make available additional benefits in using nuclear power. Upon an initiative of the U.S. Department of Energy (DOE), ten countries combine their efforts in developing such reactor concepts in the Generation IV International Forum (GIF). Argentina, Brazil, Canada, France, Japan, South Africa, South Korea, Switzerland, the United Kingdom, and the United States pursue the common objective in GIF to identify suitable nuclear power systems and promote their development up to the envisaged readiness for construction in 2030. Besides technical and economic questions of nuclear power generation, also other aspects must be considered with a view to the future use of nuclear power. The particularly relevant issues, such as the management of radioactive waste, the intensification of research and development, and international cooperation, have been taken up by the Bush administration at an early point in time and have been, or will be, incorporated in practical solutions, as in the case of the Yucca Mountain repository project. (orig.)

  8. Time-resolved electron transport in quantum-dot systems; Zeitaufgeloester Elektronentransport in Quantendotsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Croy, Alexander

    2010-06-30

    In this thesis the time-resolved electron transport in quantum dot systems was studied. For this two different formalisms were presented: The nonequilibrium Green functions and the generalized quantum master equations. For both formalisms a propagation method for the numerical calculation of time-resolved expectation values, like the occupation and the electron current, was developed. For the demonstration of the propagation method two different question formulations were considered. On the one hand the stochastically driven resonant-level model was studied. On the other hand the pulse-induced transport through a double quantum dot was considered.

  9. Exact Time-Dependent Exchange-Correlation Potential in Electron Scattering Processes

    Science.gov (United States)

    Suzuki, Yasumitsu; Lacombe, Lionel; Watanabe, Kazuyuki; Maitra, Neepa T.

    2017-12-01

    We identify peak and valley structures in the exact exchange-correlation potential of time-dependent density functional theory that are crucial for time-resolved electron scattering in a model one-dimensional system. These structures are completely missed by adiabatic approximations that, consequently, significantly underestimate the scattering probability. A recently proposed nonadiabatic approximation is shown to correctly capture the approach of the electron to the target when the initial Kohn-Sham state is chosen judiciously, and it is more accurate than standard adiabatic functionals but ultimately fails to accurately capture reflection. These results may explain the underestimation of scattering probabilities in some recent studies on molecules and surfaces.

  10. New England Wind Forum: A Wind Powering America Project, Volume 1, Issue 4 -- May 2008 (Newsletter)

    Energy Technology Data Exchange (ETDEWEB)

    Grace, R. C.; Gifford, J.

    2008-05-01

    The New England Wind Forum electronic newsletter summarizes the latest news in wind energy development activity, markets, education, and policy in the New England region. It also features an interview with a key figure influencing New England's wind energy development. Volume 1, Issue 4 features an interview with Brian Fairbank, president and CEO of Jiminy Peak Mountain Resort.

  11. New York State Forum for Information Resource Management: 1998-1999 Annual Report.

    Science.gov (United States)

    New York State Forum for Information Resource Management.

    This annual report of the New York State Forum for Information Resource Management begins with a section that summarizes key activities for 1998-99, including partnerships with other organizations, sessions on the use of information in government and information security, programs on the challenges of electronic commerce for government,…

  12. New England Wind Forum: A Wind Powering America Project, Volume 1, Issue 3 -- October 2007 (Newsletter)

    Energy Technology Data Exchange (ETDEWEB)

    Grace, R. C.; Gifford, J.

    2007-10-01

    The New England Wind Forum electronic newsletter summarizes the latest news in wind energy development activity, markets, education, and policy in the New England region. It also features an interview with a key figure influencing New England's wind energy development. Volume 1, Issue 3 features an interview with Andrew Dzykewicz, Commissioner of the Rhode Island Office of Energy Resources.

  13. Web Annotation and Threaded Forum: How Did Learners Use the Two Environments in an Online Discussion?

    Science.gov (United States)

    Sun, Yanyan; Gao, Fei

    2014-01-01

    Web annotation is a Web 2.0 technology that allows learners to work collaboratively on web pages or electronic documents. This study explored the use of Web annotation as an online discussion tool by comparing it to a traditional threaded discussion forum. Ten graduate students participated in the study. Participants had access to both a Web…

  14. Highly Integrated Mixed-Mode Electronics for the readout of Time Projection Chambers

    CERN Document Server

    França Santos, Hugo Miguel; Musa, Luciano

    Time Projection Chambers (TPCs) are one of the most prevalent particle trackers for high-energy physics experiments. Future planed TPCs for the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) entail very high spatial resolution in large gas volumes, but impose low material budget for the end caps of the TPC cylinder. This constraint is not accomplished with the state-of-the-art front-end electronics because of its unsuited relatively large mass and of its associated water cooling system. To reach the required material budget, highly compact and power efficient dedicated TPC front-end electronics should be developed. This project aims at re-designing the different electronic elements with significant improvements in terms of performance, power efficiency and versatility, and developing an integrated circuit that merges all components of the front-end electronics. This chip ambitions a large volume production at low unitary cost and its employment in multiple detectors. The design of ...

  15. Time-dependent theoretical treatments of the dynamics of electrons and nuclei in molecular systems

    International Nuclear Information System (INIS)

    Deumens, E.; Diz, A.; Longo, R.; Oehrn, Y.

    1994-01-01

    An overview is presented of methods for time-dependent treatments of molecules as systems of electrons and nuclei. The theoretical details of these methods are reviewed and contrasted in the light of a recently developed time-dependent method called electron-nuclear dynamics. Electron-nuclear dynamics (END) is a formulation of the complete dynamics of electrons and nuclei of a molecular system that eliminates the necessity of constructing potential-energy surfaces. Because of its general formulation, it encompasses many aspects found in other formulations and can serve as a didactic device for clarifying many of the principles and approximations relevant in time-dependent treatments of molecular systems. The END equations are derived from the time-dependent variational principle applied to a chosen family of efficiently parametrized approximate state vectors. A detailed analysis of the END equations is given for the case of a single-determinantal state for the electrons and a classical treatment of the nuclei. The approach leads to a simple formulation of the fully nonlinear time-dependent Hartree-Fock theory including nuclear dynamics. The nonlinear END equations with the ab initio Coulomb Hamiltonian have been implemented at this level of theory in a computer program, ENDyne, and have been shown feasible for the study of small molecular systems. Implementation of the Austin Model 1 semiempirical Hamiltonian is discussed as a route to large molecular systems. The linearized END equations at this level of theory are shown to lead to the random-phase approximation for the coupled system of electrons and nuclei. The qualitative features of the general nonlinear solution are analyzed using the results of the linearized equations as a first approximation. Some specific applications of END are presented, and the comparison with experiment and other theoretical approaches is discussed

  16. High-effective position time spectrometer in actual measurements of low intensity region of electron spectra

    International Nuclear Information System (INIS)

    Babenkov, M.I.; Zhdanov, V.S.

    2002-01-01

    Magnetic position-time spectrometer was proposed in previous work, where not only electron coordinates in focal plane are measured by position sensitive detector (PSD) but places of their birth in beta source plane of a large area are fixed using another PSD, situated behind it, by quick effects, accompanying radioactive decay. PSD on the basis of macro-channel plates are used. It is succeeded in position-time spectrometer to combine beta sources of a large area with multichannel registration for a wide energy interval, that efficiency of measurements was two orders of magnitude increase d in comparison magnetic apparatus having PSD only in focal plane. Owing to two detectors' switching on coincidence the relation effect/background in increased minimum on two orders of magnitude in comparison with the same apparatus. At some complication of mathematical analysis it was obtained, that high characteristics of position-time spectrometer are kept during the use the magnetic field, providing double focusing. Owning to this focusing the gain the efficiency of measurements will make one more order of magnitude. Presented high-effective position-time spectrometer is supposed to use in the measurements of low-intensity region of electron spectra, which are important for development of fundamental physics. This is the first of all estimation of electron anti-neutrino mass by the form of beta spectrum of tritium in the region of boundary energy. Recently here there was problem of non physical negative values. This problem can be solved by using in measurement of different in principle high-effective spectrometers, which possess improved background properties. A position-time spectrometers belongs to these apparatus, which provides the best background conditions at very large effectiveness of the measurements of tritium beta spectrum in the region of boundary energy with acceptable high resolution. An important advantage of position-time spectrometer is the possibility of

  17. The Cumbria Rural Health Forum: initiating change and moving forward with technology.

    Science.gov (United States)

    Ditchburn, Jae-Llane; Marshall, Alison

    2016-01-01

    The Cumbria Rural Health Forum was formed by a number of public, private and voluntary sector organisations to collaboratively work on rural health and social care in the county of Cumbria, England. The aim of the forum is to improve health and social care delivery for rural communities, and share practical ideas and evidence-based best practice that can be implemented in Cumbria. The forum currently consists of approximately 50 organisations interested in and responsible for delivery of health and social care in Cumbria. An exploration of digital technologies for health and care was recognised as an initial priority. This article describes a hands-on approach undertaken within the forum, including its current progress and development. The forum used a modified Delphi technique to facilitate its work on discussing ideas and reaching consensus to formulate the Cumbria Strategy for Digital Technologies in Health and Social Care. The group communication process took place over meetings and workshops held at various locations in the county. A roadmap for the implementation of digital technologies into health and social care was developed. The roadmap recommends the following: (i) to improve the health outcomes for targeted groups, within a unit, department or care pathway; (ii) to explain, clarify, share good (and bad) practice, assess impact and value through information sharing through conferences and events, influencing and advocacy for Cumbria; and (iii) to develop a digital-health-ready workforce where health and social care professionals can be supported to use digital technologies, and enhance recruitment and retention of staff. The forum experienced issues consistent with those in other Delphi studies, such as the repetition of ideas. Attendance was variable due to the unavailability of key people at times. Although the forum facilitated collective effort to address rural health issues, its power is limited to influencing and supporting implementation of change

  18. The Influence of Forums and Multilevel Governance on the Climate Adaptation Practices of Australian Organizations

    Directory of Open Access Journals (Sweden)

    Lorraine E. Bates

    2013-12-01

    Full Text Available To date, there are few regulations and policies relating to climate change in Australia. Uncertainty about the timing, structure, and potential impact of proposed legislation such as a national carbon abatement scheme, is leading to planning delays across the country. To assist with these policy uncertainties, organizations can embed themselves in multilevel governance frameworks that inform, structure, and facilitate strategic development, planning, and action. As part of these networks, organizational representatives also engage in formal and informal forums, a type of interorganizational relationship, which can include industry task forces, policy development committees, interagency groups, and specific climate change committees. Forums constitute an additional level of governance that influences decision making. The patterns of relationships within these multilevel governance frameworks are examined in this paper, with a focus on the forum level of organizational cooperation. Specifically, we investigate the type of forums operating and their role in supporting organizational responses to climate change. A series of interviews and focus groups were conducted in two study areas, the Swan Canning region of Western Australia and the Hunter / Central Coast region of New South Wales. The results indicate that organizations participate in a diverse range of forums. Further, forums appear to play a key role in the everyday business of organizations by enhancing their ability to plan and address a range of issues, including those associated with climate change. In addition the research highlights some of the barriers and drivers for the development and implementation of climate adaptation practices that emerge from forum discussions. For example, a lack of government guidance in interpreting climate change policy was described as a barrier yet access to the knowledge and expertise of participants was highlighted as a potential driver. The paper

  19. Reflections on 'medical tourism' from the 2016 Global Healthcare Policy and Management Forum.

    Science.gov (United States)

    Crooks, Valorie A; Ormond, Meghann; Jin, Ki Nam

    2017-01-01

    In October 2016, the Global Healthcare Policy and Management Forum was held at Yonsei University, Seoul, South Korea. The goal of the forum was to discuss the role of the state in regulating and supporting the development of medical tourism. Forum attendees came from 10 countries. In this short report article, we identify key lessons from the forum that can inform the direction of future scholarly engagement with medical tourism. In so doing, we reference on-going scholarly debates about this global health services practice that have appeared in multiple venues, including this very journal. Key questions for future research emerging from the forum include: who should be meaningfully involved in identifying and defining categories of those travelling across borders for health services and what risks exist if certain voices are underrepresented in such a process; who does and does not 'count' as a medical tourist and what are the implications of such quantitative assessments; why have researchers not been able to address pressing knowledge gaps regarding the health equity impacts of medical tourism; and how do national-level polices and initiatives shape the ways in which medical tourism is unfolding in specific local centres and clinics? This short report as an important time capsule that summarises the current state of medical tourism research knowledge as articulated by the thought leaders in attendance at the forum while also pushing for research growth.

  20. Image enhancement in photoemission electron microscopy by means of imaging time-of-flight analysis

    International Nuclear Information System (INIS)

    Oelsner, A.; Krasyuk, A.; Fecher, G.H.; Schneider, C.M.; Schoenhense, G.

    2004-01-01

    Photoemission electron microscopy (PEEM) is widely used in combination with synchrotron sources as a powerful tool to observe chemical and magnetic properties of metal and semiconductor surfaces. Presently, the resolution limit of these instruments using soft-X-ray excitation is limited to about 50 nm, because of the chromatic aberration of the electron optics used. Various sophisticated approaches have thus been reported for enhancing the spatial resolution in photoemission electron microscopy. This work demonstrates the use of a simple imaging energy filter based on electron time-of-flight (ToF) selection. The spatial resolution could be improved dramatically, even though the instrument was optimized using a rather large contrast aperture of 50 μm. A special (x, y, t)-resolving delayline detector was used as the imaging unit of this ToF-PEEM. It is operated in phase with the time structure of the synchrotron source, cutting time intervals from the raw image-forming data set in order to reduce the electron energy width contributing to the final images

  1. Formation time of a small electron polaron in LiNbO3: measurements and interpretation

    International Nuclear Information System (INIS)

    Qiu, Yong; Ucer, K.B.; Williams, R.T.

    2005-01-01

    Infrared optical absorption attributed to the electron polaron on a non-defective site in LiNbO 3 and KNbO 3 has previously been observed using pulsed electron and laser techniques. With subpicosecond laser excitation and spectroscopy, it is possible to measure a rise time of the infrared absorption, which may be interpreted as the time for a band-state conduction electron to cool by phonon scattering, collapse its wavefunction around a site made attractive by thermal disorder, and relax vibrationally to a small polaron. This is a process which is of fundamental interest, involving dynamics of self-localization from band states and vibrational relaxation of a localized electron in an otherwise non-defective lattice. For example, Gavartin and Shluger have recently performed calculations on the role of thermal fluctuations in self-trapping of holes in MgO. We report initial measurements on the rise time of infrared absorption at 0.95 eV (Mg-perturbed polaron) in LiNbO 3 :Mg to be τ R ∼230 fs at T=20 K and τ R ∼110 fs at T=296 K. We discuss 2 stages that together may account for the delay and its temperature dependence: free-electron cooling and vibrational relaxation of a ''defect'' (small polaron) in a host. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Time-of-flight electron energy loss spectroscopy using TM110 deflection cavities

    Directory of Open Access Journals (Sweden)

    W. Verhoeven

    2016-09-01

    Full Text Available We demonstrate the use of two TM110 resonant cavities to generate ultrashort electron pulses and subsequently measure electron energy losses in a time-of-flight type of setup. The method utilizes two synchronized microwave cavities separated by a drift space of 1.45 m. The setup has an energy resolution of 12 ± 2 eV FWHM at 30 keV, with an upper limit for the temporal resolution of 2.7 ± 0.4 ps. Both the time and energy resolution are currently limited by the brightness of the tungsten filament electron gun used. Through simulations, it is shown that an energy resolution of 0.95 eV and a temporal resolution of 110 fs can be achieved using an electron gun with a higher brightness. With this, a new method is provided for time-resolved electron spectroscopy without the need for elaborate laser setups or expensive magnetic spectrometers.

  3. Application of a digital data acquisition system for time of flight Positron annihilation-induced Auger Electron Spectroscopy

    Science.gov (United States)

    Gladen, R. W.; Chirayath, V. A.; McDonald, A. D.; Fairchild, A. J.; Chrysler, M. D.; Imam, S. K.; Koymen, A. R.; Weiss, A. H.

    We describe herein a digital data acquisition system for a time-of-flight Positron annihilation-induced Auger Electron Spectrometer. This data acquisition system consists of a high-speed digitizer collecting signals induced by Auger electrons and annihilation gammas in a multi-channel plate electron detector and a BaF2 gamma detector, respectively. The time intervals between these two signals is used to determine the times of flight of the Auger electrons, which are analyzed by algorithms based on traditional nuclear electronics methods. Ultimately, this digital data acquisition system will be expanded to incorporate the first coincidence measurements of Auger electron and annihilation gamma energies.

  4. Development of Geometrical Quality Control Real-time Analysis Program using an Electronic Portal Imaging

    International Nuclear Information System (INIS)

    Lee, Sang Rok; Jung, Kyung Yong; Jang, Min Sun; Lee, Byung Gu; Kwon, Young Ho

    2012-01-01

    To develop a geometrical quality control real-time analysis program using an electronic portal imaging to replace film evaluation method. A geometrical quality control item was established with the Eclipse treatment planning system (Version 8.1, Varian, USA) after the Electronic Portal Imaging Device (EPID) took care of the problems occurring from the fixed substructure of the linear accelerator (CL-iX, Varian, USA). Electronic portal image (single exposure before plan) was created at the treatment room's 4DTC (Version 10.2, Varian, USA) and a beam was irradiated in accordance with each item. The gaining the entire electronic portal imaging at the Off-line review and was evaluated by a self-developed geometrical quality control real-time analysis program. As for evaluation methods, the intra-fraction error was analyzed by executing 5 times in a row under identical conditions and procedures on the same day, and in order to confirm the infer-fraction error, it was executed for 10 days under identical conditions of all procedures and was compared with the film evaluation method using an Iso-align quality control device. Measurement and analysis time was measured by sorting the time into from the device setup to data achievement and the time amount after the time until the completion of analysis and the convenience of the users and execution processes were compared. The intra-fraction error values for each average 0.1, 0.2, 0.3, 0.2 mm at light-radiation field coincidence, collimator rotation axis, couch rotation axis and gantry rotation axis. By checking the infer-fraction error through 10 days of continuous quality control, the error values obtained were average 1.7, 1.4, 0.7, 1.1 mm for each item. Also, the measurement times were average 36 minutes, 15 minutes for the film evaluation method and electronic portal imaging system, and the analysis times were average 30 minutes, 22 minutes. When conducting a geometrical quality control using an electronic portal imaging

  5. Pulse radiolysis with (sub) nanosecond time resolution using a 3 MV electron accelerator

    International Nuclear Information System (INIS)

    Luthjens, L.H.

    1986-01-01

    In this thesis the development of equipment for pulse radiolysis is described and the application of the technique to time-resolved measurements of the fluorescence emission of excited states formed after irradiation of some alkanes is dealt with. A review is given of the development of the pulsed 3MV Van de Graaf electron accelerator for the generation of subnanosecond electron beam pulses and of the development of the equipment for optical detection as accomplished by the author. The initial stage of a further development for shorter pulses and higher time resolution is briefly discussed. A collection of papers on the development of apparatus and a collection of papers dealing with the results obtained from measurements of the fluorescence of excited states, formed by the recombination of electrons and ions in irradiated alkanes such as cyclohexane and the decalines, are included. (Auth.)

  6. Time-dependent density functional theory for many-electron systems interacting with cavity photons.

    Science.gov (United States)

    Tokatly, I V

    2013-06-07

    Time-dependent (current) density functional theory for many-electron systems strongly coupled to quantized electromagnetic modes of a microcavity is proposed. It is shown that the electron-photon wave function is a unique functional of the electronic (current) density and the expectation values of photonic coordinates. The Kohn-Sham system is constructed, which allows us to calculate the above basic variables by solving self-consistent equations for noninteracting particles. We suggest possible approximations for the exchange-correlation potentials and discuss implications of this approach for the theory of open quantum systems. In particular we show that it naturally leads to time-dependent density functional theory for systems coupled to the Caldeira-Leggett bath.

  7. Time-dependent electron temperature diagnostics for high-power aluminum z-pinch plasmas

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Nash, T.J.; Mock, R.C.

    1996-08-01

    Time-resolved x-ray pinhole photographs and time-integrated radially-resolved x-ray crystal-spectrometer measurements of azimuthally-symmetric aluminum-wire implosions suggest that the densest phase of the pinch is composed of a hot plasma core surrounded by a cooler plasma halo. The slope of the free-bound x-ray continuum, provides a time-resolved, model-independent diagnostic of the core electron temperature. A simultaneous measurement of the time-resolved K-shell line spectra provides the electron temperature of the spatially averaged plasma. Together, the two diagnostics support a 1-D Radiation-Hydrodynamic model prediction of a plasma whose thermalization on axis produces steep radial gradients in temperature, from temperatures in excess of a kilovolt in the core to below a kilovolt in the surrounding plasma halo

  8. General relation between the group delay and dwell time in multicomponent electron systems

    Science.gov (United States)

    Zhai, Feng; Lu, Junqiang

    2016-10-01

    For multicomponent electron scattering states, we derive a general relation between the Wigner group delay and the Bohmian dwell time. It is found that the definition of group delay should account for the phase of the spinor wave functions of propagating modes. The difference between the group delay and dwell time comes from both the interference delay and the decaying modes. For barrier tunneling of helical electrons on a surface of topological insulators, our calculations including the trigonal-warping term show that the decaying modes can contribute greatly to the group delay. The derived relation between the group delay and the dwell time is helpful to unify the two definitions of tunneling time in a quite general situation.

  9. Time-resolved electron beam phase space tomography at a soft x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Michael Röhrs

    2009-05-01

    Full Text Available High-gain free-electron lasers (FELs in the ultraviolet and x-ray regime put stringent demands on the peak current, transverse emittance, and energy spread of the driving electron beam. At the soft x-ray FEL FLASH, a transverse deflecting microwave structure (TDS has been installed to determine these parameters for the longitudinally compressed bunches, which are characterized by a narrow leading peak of high charge density and a long tail. The rapidly varying electromagnetic field in the TDS deflects the electrons vertically and transforms the time profile into a streak on an observation screen. The bunch current profile was measured single shot with an unprecedented resolution of 27 fs under FEL operating conditions. A precise single-shot measurement of the energy distribution along a bunch was accomplished by using the TDS in combination with an energy spectrometer. Variation of quadrupole strengths allowed for a determination of the horizontal emittance as a function of the longitudinal position within a bunch, the so-called slice emittance. In the bunch tail, a normalized slice emittance of about 2  μm was found, in agreement with expectations. In the leading spike, however, surprisingly large emittance values were observed, in apparent contradiction with the low emittance deduced from the measured FEL gain. By applying three-dimensional phase space tomography, we were able to show that the bunch head contains a central core of low emittance and high local current density, which is presumably the lasing part of the bunch.

  10. The quiet time structure of energetic (35--560 keV) radiation belt electrons

    International Nuclear Information System (INIS)

    Lyons, L.R.; Williams, D.J.

    1975-01-01

    Detailed Explorer 45 equatorial observations of the quiet time structure of radiation belt electrons (35--560 keV) for 1.7approximately-less-thanLapproximately-less-than5.2 are presented. Throughout the slot region and outer regions of the plasmasphere the observed pitch angle distributions are found to agree with those expected from resonant interactions with the plasmaspheric whistler mode wave band. Coulomb collisions become the dominant loss mechanism within the inner zone. The overall two-zone structure of the observed radial profiles is found to agree with the equilibrium structure expected to result from a balance between pitch angle scattering losses and radial diffusion from an average outer zone source. This agreement suggests that the dominant quiet time source and loss mechanisms have been identified and evaluated for energetic radiation belt electrons within the plasmasphere. In the outer regions of the plasmasphere (Lapprox.5) the equilibrium structure is observed to be modified by daily flux variations associated with changes in the level of magnetic activity that occur even during relatively quiet times. Within the inner region of the plasmasphere (Lapproximately-less-than3.5), electron fluxes are decoupled from these magnetic activity variations by the long time scales (>10 days) required for pitch angle and radial diffusion. Consequently, fluxes of these electrons are observed to remain nearly constant at equilibrium levels throughout the quiet periods examined

  11. Time-dependent field equations for paraxial relativistic electron beams: Beam Research Program

    International Nuclear Information System (INIS)

    Sharp, W.M.; Yu, S.S.; Lee, E.P.

    1987-01-01

    A simplified set of field equations for a paraxial relativistic electron beam is presented. These equations for the beam electrostatic potential phi and pinch potential Phi identical to A/sub z/ - phi retain previously neglected time-dependent terms and for axisymmetric beams reduce exactly to Maxwell's equations

  12. Theory of life time measurements with the scanning electron microscope: steady state

    NARCIS (Netherlands)

    Berz, F.; Kuiken, H.K.

    1976-01-01

    A theoretical steady state analysis is given of the scanning electron microscope method of measuring bulk life time in diodes, where the plane of the junction is perpendicular to the surface. The current in the junction is obtained as a function of the beam power, the beam penetration into the

  13. A New Approach in Teaching Power Electronics Control of Electrical Drives using Real-Time

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Bech, Michael Møller; Blaabjerg, Frede

    2000-01-01

    A new approach in teaching power electronics and electrical drives is achieved at the Flexible Drives System Laboratory (FDSL) from Aalborg University by using the new Total Development Environment (TDE) concept that allows a full visual block-oriented programming of dynamic real-time systems...

  14. Complexities of the storm-time characteristics of ionospheric total electron content

    International Nuclear Information System (INIS)

    Kane, R.P.

    1982-01-01

    The complexities of the storm-time variations of the ionospheric total electron content are briefly reviewed. It is suggested that large variations from storm to storm may be due to irregular flows from the auroral region towards equator. A proper study of such flows needs an elaborate network of TEC measuring instruments. The need of planning and organizing such a network is emphasized

  15. First observation of low energy electron neutrinos in a liquid argon time projection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R.; Adams, C.; Asaadi, J.; Baller, B.; Bolton, T.; Bromberg, C.; Cavanna, F.; Church, E.; Edmunds, D.; Ereditato, A.; Farooq, S.; Fitzpatrick, R. S.; Fleming, B.; Hackenburg, A.; Horton-Smith, G.; James, C.; Lang, K.; Luo, X.; Mehdiyev, R.; Page, B.; Palamara, O.; Rebel, B.; Schukraft, A.; Scanavini, G.; Soderberg, M.; Spitz, J.; Szelc, A. M.; Weber, M.; Yang, T.; Zeller, G. P.

    2017-04-06

    Liquid argon time projection chambers (LArTPCs) produce remarkable fidelity in the observation of neutrino interactions. The superior capabilities of such detectors to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino ($\

  16. Image timing and detector performance of a matrix ion-chamber electronic portal imaging device

    International Nuclear Information System (INIS)

    Greer, P.

    1996-01-01

    The Oncology Centre of Auckland Hospital recently purchased a Varian PortalVision TM electronic portal imaging device (EPID). Image acquisition times, input-output characteristics and contrast-detail curves of this matrix liquid ion-chamber EPID have been measured to examine the variation in imaging performance with acquisition mode. The variation in detector performance with acquisition mode has been examined. The HV cycle time can be increased to improve image quality. Consideration should be given to the acquisition mode and HV cycle time used when imaging to ensure adequate imaging performance with reasonable imaging time. (author)

  17. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996.Seated here at a presentation by Peter Jenni, spokesperson for the ATLAS collaboration, during the visit of Forum members and Geneva public figures are Bernard Ecoffey, Founder of the Forum Engelberg (left), and Jean-Claude Landry, Department of the Interior, Agriculture and Environment, state of Geneva. Photo 01: (left to right) Bernard Ecoffey, Jean-Claude Landry and Peter Jenni. Photos 02, 03: (left to right) Jean-Claude Landry, Bernard Ecoffey and Peter Jenni.

  18. FIAP Forum on Entrepreneurship in Physics

    Science.gov (United States)

    2015-03-01

    With the changes in science as globalization has taken root, the future role of physicists becoming a part of the industrial physics community is more imperative. When 80% of graduating physicists will not be employed in academic positions, and 50% of all jobs for these physicists will be industrial sector, the importance of bringing our next generation of scientists up to speed on industrial applications is becoming much more important with the rapid, world-wide development of technology. FIAP is initiating a forum on entrepreneurship as a major role for the next generation of scientists. As physicists are problem solvers and the entrepreneurial experience is all about problem solving: whether involving technology, building a team, or financing a business. This forum seeks to link successful entrepreneurial physicists with the upcoming generation, through the dissemination of their global expertise and experience. The forum will consist of a panel discussion and then be open to question and answers from the audience.

  19. 3rd Developers@CERN Forum

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    It's about U and I !   The Developers@CERN Forum is an event by developers, for developers, aimed at promoting knowledge and experience sharing. This edition will take place at the IT Amphitheatre, on the 13th, 14th and 15th of February afternoons. It will consist of a series of short presentations and workshops. The topic for this conference will be Frontend & User interfaces. Have you got an idea for a presentation or workshop? Then, tell us about it (deadline on 27th of January). Registration will open in November. Please subscribe to developers-forum-announce@cern.ch mailing list for further information. This event will be made by developers for developers. We are counting on your presence, but also on your contributions! To learn more about the initiative, read the CERN Bulletin article. Organization You can get in touch us at developers-forum-organizers@cern.ch.

  20. Proceedings of the 2008 air issues forum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This forum focused on air related issues of concern to the oil and gas industry, regulators, researchers and the public. It included technological advances, new research projects, case studies, demonstrations, and updates to environmental regulations. Both the provincial and federal governments have recently announced new and significant reduction targets for air emissions that will have impacts on upstream oil and gas (UOG) companies. This forum reviewed what has been proposed and why and outlined the potential implications for producers. New regulatory processes and their requirements were also discussed along with ongoing industry sponsored air related research and emerging air related issues such as soot formation during flaring, sour gas flare combustion simulation modelling and fugitive emissions reduction. Ten presentations were featured at this forum, of which 3 have been catalogued separately for inclusion in this database. tabs. figs.

  1. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: Raymond Battistella - Director-General of SIG, Geneva's utilities provider (left) - and Bernard Ecoffey, Founder of the Forum Engelberg. In the background is the CMS magnet system under construction. The red concentric rings are part of the barrel yoke, which returns the magnetic flux generated by the superconducting coil. Supported from the innermost barrel ring is the outer cylinder of the vacuum tank that will house the superconducting coil. Photo 02: Alexander Höchli, member of the Institutional Committee of Forum Engelberg and former Landammann of the canton of Obwalden (left), with Raymond Battistella, Di...

  2. Proceedings of the 2008 air issues forum

    International Nuclear Information System (INIS)

    2008-01-01

    This forum focused on air related issues of concern to the oil and gas industry, regulators, researchers and the public. It included technological advances, new research projects, case studies, demonstrations, and updates to environmental regulations. Both the provincial and federal governments have recently announced new and significant reduction targets for air emissions that will have impacts on upstream oil and gas (UOG) companies. This forum reviewed what has been proposed and why and outlined the potential implications for producers. New regulatory processes and their requirements were also discussed along with ongoing industry sponsored air related research and emerging air related issues such as soot formation during flaring, sour gas flare combustion simulation modelling and fugitive emissions reduction. Ten presentations were featured at this forum, of which 3 have been catalogued separately for inclusion in this database. tabs. figs

  3. Thermal relaxation time of a mixture of relativistic electrons and neutrinos

    International Nuclear Information System (INIS)

    Herrera, M.A.; Hacyan, S.

    1987-01-01

    The interaction between the components of a relativistic binary mixture is studied by means of a fully covariant formalism. Assuming both components to differ slightly in temperature, an application of the relativistic Boltzmann equation yields general expressions for the energy transfer rate and for the relaxation time of the system. The resulting relation is then applied to a mixture of relativistic electrons and neutrinos to obtain numerical values of its relaxation time. (author)

  4. Time-lapse misorientation maps for the analysis of electron backscatter diffraction data from evolving microstructures

    International Nuclear Information System (INIS)

    Wheeler, J.; Cross, A.; Drury, M.; Hough, R.M.; Mariani, E.; Piazolo, S.; Prior, D.J.

    2011-01-01

    A 'time-lapse misorientation map' is defined here as a map which shows the orientation change at each point in an evolving crystalline microstructure between two different times. Electron backscatter diffraction data from in situ heating experiments can be used to produce such maps, which then highlight areas of microstructural change and also yield statistics indicative of how far different types of boundary (with different misorientations) have moved.

  5. Solar wind ∼0.1-1.5 keV electrons at quiet times

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Jiawei; Wang, Linghua, E-mail: wanglhwang@gmail.com; Zong, Qiugang; He, Jiansen; Tu, Chuanyi [School of Earth and Space Science, Peking University, Beijing 100871 (China); Li, Gang [Department of Physics and CSPAR, University of Alabama in Huntsville, Alabama 35899 (United States); Salem, Chadi S.; Bale, Stuart D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Wimmer-Schweingruber, Robert F. [Institute for Experimental and Applied Physics, University of Kiel (Germany)

    2016-03-25

    We present a statistical survey of the energy spectrum of solar wind suprathermal (∼0.1-1.5 keV) electrons measured by the WIND 3-D Plasma & Energetic Particle (3DP) instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. Firstly, we separate strahl (beaming) electrons and halo (isotropic) electrons based on their features in pitch angle distributions. Secondly, we fit the observed energy spectrum of both the strahl and halo electrons at ∼0.1-1.5 keV to a Kappa distribution function with an index κ, effective temperature T{sub eff} and density n{sub 0}. We also integrate the the measurements over ∼0.1-1.5 keV to obtain the average electron energy E{sub avg} of the strahl and halo. We find a strong positive correlation between κ and T{sub eff} for both the strahl and halo, possibly reflecting the nature of the generation of these suprathermal electrons. Among the 245 selected samples, ∼68% have the halo κ smaller than the strahl κ, while ∼50% have the halo E{sub h} larger than the strahl E{sub s}.

  6. Time-resolved energy spectrum of a pseudospark-produced high-brightness electron beam

    International Nuclear Information System (INIS)

    Myers, T.J.; Ding, B.N.; Rhee, M.J.

    1992-01-01

    The pseudospark, a fast low-pressure gas discharge between a hollow cathode and a planar anode, is found to be an interesting high-brightness electron beam source. Typically, all electron beam produced in the pseudospark has the peak current of ∼1 kA, pulse duration of ∼50 ns, and effective emittance of ∼100 mm-mrad. The energy information of this electron beam, however, is least understood due to the difficulty of measuring a high-current-density beam that is partially space-charge neutralized by the background ions produced in the gas. In this paper, an experimental study of the time-resolved energy spectrum is presented. The pseudospark produced electron beam is injected into a vacuum through a small pinhole so that the electrons without background ions follow single particle motion; the beam is sent through a negative biased electrode and the only portion of beam whose energy is greater than the bias voltage can pass through the electrode and the current is measured by a Faraday cup. The Faraday cup signals with various bias voltage are recorded in a digital oscilloscope. The recorded waveforms are then numerically analyzed to construct a time-resolved energy spectrum. Preliminary results are presented

  7. Suppression of the Transit -Time Instability in Large-Area Electron Beam Diodes

    Science.gov (United States)

    Myers, Matthew C.; Friedman, Moshe; Swanekamp, Stephen B.; Chan, Lop-Yung; Ludeking, Larry; Sethian, John D.

    2002-12-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm × 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%.

  8. Suppression of the transit-time instability in large-area electron beam diodes

    International Nuclear Information System (INIS)

    Myers, Matthew C.; Friedman, Moshe; Sethian, John D.; Swanekamp, Stephen B.; Chan, L.-Y.; Ludeking, Larry

    2002-01-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm x 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%

  9. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    International Nuclear Information System (INIS)

    LaGrange, Thomas; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley; Kim, Judy S.; Browning, Nigel D.

    2008-01-01

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions

  10. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    Energy Technology Data Exchange (ETDEWEB)

    LaGrange, Thomas [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States)], E-mail: lagrange@llnl.gov; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Kim, Judy S.; Browning, Nigel D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Department of Chemical Engineering and Materials Science, University of California, One Shields Avenue, Davis, CA 95616 (United States)

    2008-10-15

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions.

  11. Nonadiabatic Dynamics for Electrons at Second-Order: Real-Time TDDFT and OSCF2.

    Science.gov (United States)

    Nguyen, Triet S; Parkhill, John

    2015-07-14

    We develop a new model to simulate nonradiative relaxation and dephasing by combining real-time Hartree-Fock and density functional theory (DFT) with our recent open-systems theory of electronic dynamics. The approach has some key advantages: it has been systematically derived and properly relaxes noninteracting electrons to a Fermi-Dirac distribution. This paper combines the new dissipation theory with an atomistic, all-electron quantum chemistry code and an atom-centered model of the thermal environment. The environment is represented nonempirically and is dependent on molecular structure in a nonlocal way. A production quality, O(N(3)) closed-shell implementation of our theory applicable to realistic molecular systems is presented, including timing information. This scaling implies that the added cost of our nonadiabatic relaxation model, time-dependent open self-consistent field at second order (OSCF2), is computationally inexpensive, relative to adiabatic propagation of real-time time-dependent Hartree-Fock (TDHF) or time-dependent density functional theory (TDDFT). Details of the implementation and numerical algorithm, including factorization and efficiency, are discussed. We demonstrate that OSCF2 approaches the stationary self-consistent field (SCF) ground state when the gap is large relative to k(b)T. The code is used to calculate linear-response spectra including the effects of bath dynamics. Finally, we show how our theory of finite-temperature relaxation can be used to correct ground-state DFT calculations.

  12. How well do time-integrated Kα images represent hot electron spatial distributions?

    Science.gov (United States)

    Ovchinnikov, V. M.; Kemp, G. E.; Schumacher, D. W.; Freeman, R. R.; Van Woerkom, L. D.

    2011-07-01

    A computational study is described, which addresses how well spatially resolved time-integrated Kα images recorded in intense laser-plasma experiments correlate with the distribution of "hot" (>1 MeV) electrons as they propagate through the target. The hot electron angular distribution leaving the laser-plasma region is critically important for many applications such as Fast Ignition or laser based x-ray sources; and Kα images are commonly used as a diagnostic. It is found that Kα images can easily mislead due to refluxing and other effects. Using the particle-in-cell code LSP, it is shown that a Kα image is not solely determined by the initial population of forward directed hot electrons, but rather also depends upon "delayed" hot electrons, and in fact continues to evolve long after the end of the laser interaction. Of particular note, there is a population of hot electrons created during the laser-plasma interaction that acquire a velocity direction opposite that of the laser and subsequently reflux off the front surface of the target, deflect when they encounter magnetic fields in the laser-plasma region, and then traverse the target in a wide spatial distribution. These delayed fast electrons create significant features in the Kα time-integrated images. Electrons refluxing from the sides and the back of the target are also found to play a significant role in forming the final Kα image. The relative contribution of these processes is found to vary depending on depth within target. These effects make efforts to find simple correlations between Kα images and, for example, Fast Ignition relevant parameters prone to error. Suggestions for future target design are provided.

  13. SU-F-P-03: Management of Time to Treatment Inititation: Case for An Electronic Whiteboard

    Energy Technology Data Exchange (ETDEWEB)

    Adnani, N [The Global Medical Physics Institute, Irvine, CA (United States)

    2016-06-15

    Purpose: To determine if data mining of an electronic whiteboard improves the management of the Time to Treatment Initiation (TTI) in radiation oncology. Methods: An electronic whiteboard designed to help in managing the planning workflow and improves communication regarding patient planning progress was used to record the dates at which each phase of the planning process began or completed. These are CT Sim date, Plan Start, Physician Review, Physicist Review, Approval for Treatment Delivery, Setup or Verification of Simulation. Results: During clinical implementation, the electronic whiteboard was able to fulfill its primary objective of providing a transparent account of the planning progress of each patient. Peer pressure also meant that individual tasks, such as contouring, were easily brought to the attention of the responsible party and prioritized accordingly. Data mining to analyze the electronic whiteboard per patient (figure 1), per diagnosis (figure 2), per treatment modality (figure 3), per physician (figure 4), per planner (figure 5), etc., added another sophisticated tool in the management of Time to Treatment Initiation without compromising quality of the plans being generated. A longer than necessary time between CT Sim and Plan Start can be discussed among the members of the treatment team as an indication of inadequate/outdated CT Simulator, Contouring Tools, Image Fusion Tools, Other Imaging Studies (MRI, PET/CT) performed, etc. The same for the Plan Start to Physician Review where an extended time than expected may be due unrealistic planning goals, limited planning system features, etc. Conclusion: An Electronic Whiteboard in radiation oncology is not only helping with organizing planning workflow, it is also a potent tool that can be used to reduce the Time to Treatment Initiation by providing the clinic with hard data about the duration of each phase treatment planning as a function of different variable affecting the planning process. The

  14. SU-F-P-03: Management of Time to Treatment Inititation: Case for An Electronic Whiteboard

    International Nuclear Information System (INIS)

    Adnani, N

    2016-01-01

    Purpose: To determine if data mining of an electronic whiteboard improves the management of the Time to Treatment Initiation (TTI) in radiation oncology. Methods: An electronic whiteboard designed to help in managing the planning workflow and improves communication regarding patient planning progress was used to record the dates at which each phase of the planning process began or completed. These are CT Sim date, Plan Start, Physician Review, Physicist Review, Approval for Treatment Delivery, Setup or Verification of Simulation. Results: During clinical implementation, the electronic whiteboard was able to fulfill its primary objective of providing a transparent account of the planning progress of each patient. Peer pressure also meant that individual tasks, such as contouring, were easily brought to the attention of the responsible party and prioritized accordingly. Data mining to analyze the electronic whiteboard per patient (figure 1), per diagnosis (figure 2), per treatment modality (figure 3), per physician (figure 4), per planner (figure 5), etc., added another sophisticated tool in the management of Time to Treatment Initiation without compromising quality of the plans being generated. A longer than necessary time between CT Sim and Plan Start can be discussed among the members of the treatment team as an indication of inadequate/outdated CT Simulator, Contouring Tools, Image Fusion Tools, Other Imaging Studies (MRI, PET/CT) performed, etc. The same for the Plan Start to Physician Review where an extended time than expected may be due unrealistic planning goals, limited planning system features, etc. Conclusion: An Electronic Whiteboard in radiation oncology is not only helping with organizing planning workflow, it is also a potent tool that can be used to reduce the Time to Treatment Initiation by providing the clinic with hard data about the duration of each phase treatment planning as a function of different variable affecting the planning process. The

  15. The Magnetic Local Time Distribution of Energetic Electrons in the Radiation Belt Region

    Science.gov (United States)

    Allison, H. J.

    2017-12-01

    Using fourteen years of electron flux data from the National Oceanic and Atmospheric Administration Polar Operational Environmental Satellites (POES), a statistical study of the magnetic local time (MLT) distribution of the electron population is performed across a range of activity levels, defined by AE, AE*, Kp, solar wind velocity (Vsw), and VswBz. Three electron energies (>30, >100, and >300 keV) are considered. Dawn-dusk flux asymmetries larger than order of magnitude were observed for >30 and >100 keV electrons. For >300 keV electrons, dawn-dusk asymmetries were primarily due to a decrease in the average dusk-side flux beyond L* ˜ 4.5 that arose with increasing activity. For the >30 keV population, substorm injections enhance the dawn-side flux, which may not reach the dusk-side as the electrons can be on open drift paths and lost to the magnetopause. The asymmetries in the >300 keV population are attributed to the combination of magnetopause shadowing and >300 keV electron injections by large electric fields. We suggest that 3D radiation belt models could set the minimum energy boundary (Emin) to 30 keV or above at L* ˜6 during periods of low activity. However, for more moderate conditions, Emin should be larger than 100 keV and, for very extreme activities, ˜300 keV. Our observations show the extent that in-situ electron flux readings may vary during active periods due to the MLT of the satellite and highlight the importance of 4D radiation belt models to fully understand radiation belt processes.

  16. Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework

    International Nuclear Information System (INIS)

    Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A.; Oviedo, M. Belén; Sánchez, Cristián G.; Lebrero, Mariano C. González

    2014-01-01

    This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data

  17. GreyGuide Forum and Repository

    OpenAIRE

    Biagioni, Stefania; Farace, Dominic

    2014-01-01

    We present the GreyGuide: an online forum and repository of good practice in the field of grey literature. The launch of the GreyGuide Repository took place in December 2013 at the Fifteenth International Conference on Grey Literature. Since then, the acquisition of both proposed and published good practices are underway. The GreyGuide as an online forum is currently in a developmental stage and is influenced by the changes that have taken place in GreyNet's new infrastructure commencing in J...

  18. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Photo 01: Members of the Forum Engelberg and public figures from Geneva visit SM18, the test hall for LHC magnets: (left to right) N. Siegel, Prof. Dr. Med. Bernard Mach, Mr Alexander Höchli, H. Wenninger, Mrs Mireille Quirina, Mme Konrade Von Bremen, Mrs Thérèse Wolf, Prof. Roger Berthouzoz, Mrs Marie-Anne Heimo, Mr Bernard Ecoffey.

  19. Major economies Forum on energy and climate

    International Nuclear Information System (INIS)

    2009-01-01

    The Major Economies Forum is intended to facilitate an open dialogue among major developed and developing economies, help generate the political leadership necessary to achieve a successful outcome at the United Nations climatic change conference in Copenhagen, and advance the exploration of concrete initiatives and joint ventures that increase the supply of clean energy while cutting greenhouse gas emissions. The Forum's second preparatory meeting was held in Paris in May 2009, mainly focused on greenhouse gas emissions reduction actions and objectives, the diffusion of clean technologies, the financing of activities for climate protection and adaptation to climatic change impacts

  20. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Horst Wenninger (left) in animated discussion with Alexander Höchli, member of the Institutional Committee of Forum Engelberg and former Landammann of the canton of Obwalden.

  1. Correlated electron dynamics and memory in time-dependent density functional theory

    International Nuclear Information System (INIS)

    Thiele, Mark

    2009-01-01

    Time-dependent density functional theory (TDDFT) is an exact reformulation of the time-dependent many-electron Schroedinger equation, where the problem of many interacting electrons is mapped onto the Kohn-Sham system of noninteracting particles which reproduces the exact electronic density. In the Kohn-Sham system all non-classical many-body effects are incorporated in the exchange-correlation potential which is in general unknown and needs to be approximated. It is the goal of this thesis to investigate the connection between memory effects and correlated electron dynamics in strong and weak fields. To this end one-dimensional two-electron singlet systems are studied. At the same time these systems include the onedimensional helium atom model, which is an established system to investigate the crucial effects of correlated electron dynamics in external fields. The studies presented in this thesis show that memory effects are negligible for typical strong field processes. Here the approximation of the spatial nonlocality is of primary importance. For the photoabsorption spectra on the other hand the neglect of memory effects leads to qualitative and quantitative errors, which are shown to be connected to transitions of double excitation character. To develop a better understanding of the conditions under which memory effects become important quantum fluid dynamics has been found to be especially suitable. It represents a further exact reformulation of the quantum mechanic many-body problem which is based on hydrodynamic quantities such as density and velocity. Memory effects are shown to be important whenever the velocity field develops strong gradients and dissipative effects contribute. (orig.)

  2. Correlated electron dynamics and memory in time-dependent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, Mark

    2009-07-28

    Time-dependent density functional theory (TDDFT) is an exact reformulation of the time-dependent many-electron Schroedinger equation, where the problem of many interacting electrons is mapped onto the Kohn-Sham system of noninteracting particles which reproduces the exact electronic density. In the Kohn-Sham system all non-classical many-body effects are incorporated in the exchange-correlation potential which is in general unknown and needs to be approximated. It is the goal of this thesis to investigate the connection between memory effects and correlated electron dynamics in strong and weak fields. To this end one-dimensional two-electron singlet systems are studied. At the same time these systems include the onedimensional helium atom model, which is an established system to investigate the crucial effects of correlated electron dynamics in external fields. The studies presented in this thesis show that memory effects are negligible for typical strong field processes. Here the approximation of the spatial nonlocality is of primary importance. For the photoabsorption spectra on the other hand the neglect of memory effects leads to qualitative and quantitative errors, which are shown to be connected to transitions of double excitation character. To develop a better understanding of the conditions under which memory effects become important quantum fluid dynamics has been found to be especially suitable. It represents a further exact reformulation of the quantum mechanic many-body problem which is based on hydrodynamic quantities such as density and velocity. Memory effects are shown to be important whenever the velocity field develops strong gradients and dissipative effects contribute. (orig.)

  3. A real-time extension of density matrix embedding theory for non-equilibrium electron dynamics

    Science.gov (United States)

    Kretchmer, Joshua S.; Chan, Garnet Kin-Lic

    2018-02-01

    We introduce real-time density matrix embedding theory (DMET), a dynamical quantum embedding theory for computing non-equilibrium electron dynamics in strongly correlated systems. As in the previously developed static DMET, real-time DMET partitions the system into an impurity corresponding to the region of interest coupled to the surrounding environment, which is efficiently represented by a quantum bath of the same size as the impurity. In this work, we focus on a simplified single-impurity time-dependent formulation as a first step toward a multi-impurity theory. The equations of motion of the coupled impurity and bath embedding problem are derived using the time-dependent variational principle. The accuracy of real-time DMET is compared to that of time-dependent complete active space self-consistent field (TD-CASSCF) theory and time-dependent Hartree-Fock (TDHF) theory for a variety of quantum quenches in the single impurity Anderson model (SIAM), in which the Hamiltonian is suddenly changed (quenched) to induce a non-equilibrium state. Real-time DMET shows a marked improvement over the mean-field TDHF, converging to the exact answer even in the non-trivial Kondo regime of the SIAM. However, as expected from analogous behavior in static DMET, the constrained structure of the real-time DMET wavefunction leads to a slower convergence with respect to active space size, in the single-impurity formulation, relative to TD-CASSCF. Our initial results suggest that real-time DMET provides a promising framework to simulate non-equilibrium electron dynamics in which strong electron correlation plays an important role, and lays the groundwork for future multi-impurity formulations.

  4. Dead time of different neutron detectors associated with a pulsed electronics with current collection

    International Nuclear Information System (INIS)

    Bacconnet, Eugene; Duchene, Jean; Duquesne, Henry; Schmitt, Andre

    1968-01-01

    After having outlined that the development of fast neutron reactor physics, notably kinetics, requires highly efficient neutron detectors and pulse measurement chains able to cope with high counting rates, the authors report the measurement of dead time of various neutron detectors which are used in the experimental study of fast neutron reactors. They present the SAITB 1 electronic measurement set, its components, its general characteristics, the protected connection between the detector and the electronics. They present and report the experiment: generalities about detector location and measurements, studied detectors (fission chambers, boron counters), and report the exploitation of the obtained results (principle, data, high-threshold counting gain) [fr

  5. Paramagnetic relaxation effects in perturbed angular correlations for arbitrary electronic relaxation time

    International Nuclear Information System (INIS)

    Chopin, C.; Spanjaard, D.; Hartmann-Boutron, F.

    1975-01-01

    Previous perturbation treatments of paramagnetic relaxation effects in γγ PAC were limited to the case of very short electronic relaxation times. This limitation is circumvented by invoking a new perturbation theory recently elaborated by Hirst and others for handling relaxation effects in Moessbauer spectra. Under the assumption of spherical electronic relaxation the perturbation factors are computed as functions of certain relaxation parameters which are directly related to the microscopic relaxation Hamiltonian. The results are compared to those of the stochastic theory of Scherer and Blume [fr

  6. Electro-optic sampling for time resolving relativistic ultrafast electron diffraction

    International Nuclear Information System (INIS)

    Scoby, C. M.; Musumeci, P.; Moody, J.; Gutierrez, M.; Tran, T.

    2009-01-01

    The Pegasus laboratory at UCLA features a state-of-the-art electron photoinjector capable of producing ultrashort (<100 fs) high-brightness electron bunches at energies of 3.75 MeV. These beams recently have been used to produce static diffraction patterns from scattering off thin metal foils, and it is foreseen to take advantage of the ultrashort nature of these bunches in future pump-probe time-resolved diffraction studies. In this paper, single shot 2-d electro-optic sampling is presented as a potential technique for time of arrival stamping of electron bunches used for diffraction. Effects of relatively low bunch charge (a few 10's of pC) and modestly relativistic beams are discussed and background compensation techniques to obtain high signal-to-noise ratio are explored. From these preliminary tests, electro-optic sampling is suitable to be a reliable nondestructive time stamping method for relativistic ultrafast electron diffraction at the Pegasus lab.

  7. Measuring the Capacity and Transaction Time of Cash and Electronic Toll Collection Systems

    Directory of Open Access Journals (Sweden)

    Rudy Hermawan Karsaman

    2014-07-01

    Full Text Available A long queue can occur at tollgates due to the amount of transaction time required to perform ticket payment and toll fee collection. This problem can be addressed by the use of an electronic toll collection (ETC system. A case study conducted on the Jakarta Intra Urban, Cikupa-Merak, and Cawang Pluit Toll Roads suggests that the queueing at the tollgates when modelled followed a Poisson distribution. The average cash transaction time was approximately 5 to 6 seconds, while the ETC transaction time was only 4 seconds. Furthermore, the capacity of the cash system gate was 550 to 620 vehicles/hour (which is above the minimum service standard of 450 vehicles/hour,whereas the electronic gate capacity was 770 to 870 vehicles/hour. This study demonstrates that the ETC system is more effective than the cash system in terms of reducing the number of queueing vehicles.

  8. Studying electron distributions using the time-resolved free-bound spectra from coronal plasmas

    International Nuclear Information System (INIS)

    Matthews, D.L.; Kauffman, R.L.; Kilkenny, J.D.; Lee, R.W.

    1982-11-01

    Absorption of laser light in a plasma by inverse bremsstrahlung, I.B., can lead to a non-Maxwellian velocity distribution provided the electron-elecron collision frequency is too low to equilibrate the velocity distribution in the coronal plasma region of a laser heated aluminum disk by measuring the radiation recombination continuum. The experiments are performed using lambda/sub L/ = 0.532 μm laser light at intensities of approx. 10 16 W/cm 2 . Such parameters are predicted to produce conditions suitable for a non-thermal electron distribution. The shape of the K-shell recombination radiation has been measured using a time-resolved x-ray spectrograph. The electron distribution can be determined from deconvolution of the recombination continuum shape

  9. Attosecond time-energy structure of X-ray free-electron laser pulses

    Science.gov (United States)

    Hartmann, N.; Hartmann, G.; Heider, R.; Wagner, M. S.; Ilchen, M.; Buck, J.; Lindahl, A. O.; Benko, C.; Grünert, J.; Krzywinski, J.; Liu, J.; Lutman, A. A.; Marinelli, A.; Maxwell, T.; Miahnahri, A. A.; Moeller, S. P.; Planas, M.; Robinson, J.; Kazansky, A. K.; Kabachnik, N. M.; Viefhaus, J.; Feurer, T.; Kienberger, R.; Coffee, R. N.; Helml, W.

    2018-04-01

    The time-energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modulations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science.

  10. Universal behaviour in the stock market: Time dynamics of the electronic orderbook

    Science.gov (United States)

    Kızılersü, Ayşe; Kreer, Markus; Thomas, Anthony W.; Feindt, Michael

    2016-07-01

    A consequence of the digital revolution is that share trading at the stock exchange takes place via electronic order books which are accessed by traders and investors via the internet. Our empirical findings of the London Stock Exchange demonstrate that once ultra-high frequency manipulation on time scales less than around ten milliseconds is excluded, all relevant changes in the order book happen with time differences that are randomly distributed and well described by a left-truncated Weibull distribution with universal shape parameter (independent of time and same for all stocks). The universal shape parameter corresponds to maximum entropy of the distribution.

  11. Measurements of electron avalanche formation time in W-band microwave air breakdown

    International Nuclear Information System (INIS)

    Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J.

    2011-01-01

    We present measurements of formation times of electron avalanche ionization discharges induced by a focused 110 GHz millimeter-wave beam in atmospheric air. Discharges take place in a free volume of gas, with no nearby surfaces or objects. When the incident field amplitude is near the breakdown threshold for pulsed conditions, measured formation times are ∼0.1-2 μs over the pressure range 5-700 Torr. Combined with electric field breakdown threshold measurements, the formation time data shows the agreement of 110 GHz air breakdown with the similarity laws of gas discharges.

  12. Three axis electronic flight motion simulator real time control system design and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhiyuan; Miao, Zhonghua, E-mail: zhonghua-miao@163.com; Wang, Xiaohua [School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200072 (China); Wang, Xuyong [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-12-15

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  13. Measurements of electron avalanche formation time in W-band microwave air breakdown

    Science.gov (United States)

    Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J.

    2011-08-01

    We present measurements of formation times of electron avalanche ionization discharges induced by a focused 110 GHz millimeter-wave beam in atmospheric air. Discharges take place in a free volume of gas, with no nearby surfaces or objects. When the incident field amplitude is near the breakdown threshold for pulsed conditions, measured formation times are ˜0.1-2 μs over the pressure range 5-700 Torr. Combined with electric field breakdown threshold measurements, the formation time data shows the agreement of 110 GHz air breakdown with the similarity laws of gas discharges.

  14. Three axis electronic flight motion simulator real time control system design and implementation.

    Science.gov (United States)

    Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

    2014-12-01

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  15. Dancing with the Electrons: Time-Domain and CW In Vivo EPR Imaging

    Directory of Open Access Journals (Sweden)

    Murali C. Krishna

    2008-01-01

    Full Text Available The progress in the development of imaging the distribution of unpaired electrons in living systems and the functional and the potential diagnostic dimensions of such an imaging process, using Electron Paramagnetic Resonance Imaging (EPRI, is traced from its origins with emphasis on our own work. The importance of EPR imaging stems from the fact that many paramagnetic probes show oxygen dependent spectral broadening. Assessment of in vivo oxygen concentration is an important factor in radiation oncology in treatment-planning and monitoring treatment-outcome. The emergence of narrow-line trairylmethyl based, bio-compatible spin probes has enabled the development of radiofrequency time-domain EPRI. Spectral information in time-domain EPRI can be achieved by generating a time sequence of T2* or T2 weighted images. Progress in CW imaging has led to the use of rotating gradients, more recently rapid scan with direct detection, and a combination of all the three. Very low field MRI employing Dynamic Nuclear polarization (Overhauser effect is also employed for monitoring tumor hypoxia, and re-oxygenation in vivo. We have also been working on the co-registration of MRI and time domain EPRI on mouse tumor models at 300 MHz using a specially designed resonator assembly. The mapping of the unpaired electron distribution and unraveling the spectral characteristics by using magnetic resonance in presence of stationary and rotating gradients in indeed ‘dancing with the (unpaired electrons’, metaphorically speaking.

  16. Dancing with the Electrons: Time-Domain and CW EPR Imaging

    Directory of Open Access Journals (Sweden)

    Sankaran Subramanian

    2008-01-01

    Full Text Available The progress in the development of imaging the distribution of unpaired electrons in living systems and the functional and the potential diagnostic dimensions of such an imaging process, using Electron Paramagnetic Resonance Imaging (EPRI, is traced from its origins with emphasis on our own work. The importance of EPR imaging stems from the fact that many paramagnetic probes show oxygen dependent spectral broadening. Assessment of in vivo oxygen concentration is an important factor in radiation oncology in treatment-planning and monitoring treatment-outcome. The emergence of narrow-line trairylmethyl based, bio-compatible spin probes has enabled the development of radiofrequency time-domain EPRI. Spectral information in time-domain EPRI can be achieved by generating a time sequence of T 2 * or T 2 weighted images. Progress in CW imaging has led to the use of rotating gradients, more recently rapid scan with direct detection, and a combination of all the three. Very low field MRI employing Dynamic Nuclear polarization (Overhauser effect is also employed for monitoring tumor hypoxia, and re-oxygenation in vivo . We have also been working on the co-registration of MRI and time domain EPRI on mouse tumor models at 300 MHz using a specially designed resonator assembly. The mapping of the unpaired electron distribution and unraveling the spectral characteristics by using magnetic resonance in presence of stationary and rotating gradients in indeed ‘dancing with the ( unpaired electrons’, metaphorically speaking.

  17. Real-time observation of cascaded electronic relaxation processes in p-Fluorotoluene

    Science.gov (United States)

    Hao, Qiaoli; Deng, Xulan; Long, Jinyou; Wang, Yanmei; Abulimiti, Bumaliya; Zhang, Bing

    2017-08-01

    Ultrafast electronic relaxation processes following two photoexcitation of 400 nm in p-Fluorotoluene (pFT) have been investigated utilizing time-resolved photoelectron imaging coupled with time-resolved mass spectroscopy. Cascaded electronic relaxation processes started from the electronically excited S2 state are directly imaged in real time and well characterized by two distinct time constants of 85 ± 10 fs and 2.4 ± 0.3 ps. The rapid component corresponds to the lifetime of the initially excited S2 state, including the structure relaxation from the Franck-Condon region to the conical intersection of S2/S1 and the subsequent internal conversion to the highly excited S1 state. While, the slower relaxation constant is attributed to the further internal conversion to the high levels of S0 from the secondarily populated S1 locating in the channel three region. Moreover, dynamical differences with benzene and toluene of analogous structures, including, specifically, the slightly slower relaxation rate of S2 and the evidently faster decay of S1, are also presented and tentatively interpreted as the substituent effects. In addition, photoelectron kinetic energy and angular distributions reveal the feature of accidental resonances with low-lying Rydberg states (the 3p, 4s and 4p states) during the multi-photon ionization process, providing totally unexpected but very interesting information for pFT.

  18. Time of flight spectra of electrons emitted from graphite after positron annihilation

    International Nuclear Information System (INIS)

    Gladen, R W; Chirayath, V A; Chrysler, M D; Mcdonald, A D; Fairchild, A J; Shastry, K; Koymen, A R; Weiss, A H

    2017-01-01

    Low energy (∼2 eV) positrons were deposited onto the surface of highly oriented pyrolytic graphite (HOPG) using a positron beam equipped with a time of flight (TOF) spectrometer. The energy of the electrons emitted as a result of various secondary processes due to positron annihilation was measured using the University of Texas at Arlington’s (UTA) TOF spectrometer. The positron annihilation-induced electron spectra show the presence of a carbon KLL Auger peak at ∼263 eV. The use of a very low energy beam allowed us to observe a new feature not previously seen: a broad peak which reached to a maximum intensity at ∼4 eV and extended up to a maximum energy of ∼15 eV. The low energy nature of the peak was confirmed by the finding that the peak was eliminated when a tube in front of the sample was biased at -15 V. The determination that the electrons in the peak are leaving the surface with energies up to 7 times the incoming positron energy indicates that the electrons under the broad peak were emitted as a result of a positron annihilation related process. (paper)

  19. Quantum electrodynamical time-dependent density functional theory for many-electron systems on a lattice

    Science.gov (United States)

    Farzanehpour, Mehdi; Tokatly, Ilya; Nano-Bio Spectroscopy Group; ETSF Scientific Development Centre Team

    2015-03-01

    We present a rigorous formulation of the time-dependent density functional theory for interacting lattice electrons strongly coupled to cavity photons. We start with an example of one particle on a Hubbard dimer coupled to a single photonic mode, which is equivalent to the single mode spin-boson model or the quantum Rabi model. For this system we prove that the electron-photon wave function is a unique functional of the electronic density and the expectation value of the photonic coordinate, provided the initial state and the density satisfy a set of well defined conditions. Then we generalize the formalism to many interacting electrons on a lattice coupled to multiple photonic modes and prove the general mapping theorem. We also show that for a system evolving from the ground state of a lattice Hamiltonian any density with a continuous second time derivative is locally v-representable. Spanish Ministry of Economy and Competitiveness (Grant No. FIS2013-46159-C3-1-P), Grupos Consolidados UPV/EHU del Gobierno Vasco (Grant No. IT578-13), COST Actions CM1204 (XLIC) and MP1306 (EUSpec).

  20. Delta-electron spectroscopy: An aid for the determination of reaction times in heavy ion reactions

    International Nuclear Information System (INIS)

    Skapa, H.

    1983-01-01

    For the systems I->Au and I->Bi at an incident energy of 6.2 MeV/u (I->Au) and 6.6 MeV/u (I->Bi) the emission probability of delta electrons was determined. In an energy range from 150 KeV to 1000 KeV electrons were spectroscoped in coincidence to elastically, quasielastically, and deep inelastically scattered ions. In deep inelastic reaction between reaction products with high and without a mean mass drift was discriminated. The contribution of the conversion electrons, determined from gamma spectra, extends in the range of deep inelastic reactions of about 60%. While the ratio of conversion electrons for deep inelastic events with large to such without mass drift shows a flat, monotoneous growth for the ratio of the measured emission probabilities a oscillation-like structure with about 400 KeV width results. An interpretation of this structure as interference effect by nuclear time delay yields for the case of large mass drift a nuclear retention time of 7.5 x 10 -21 s. (orig./HSI) [de

  1. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1991-01-01

    This report contains highlights from the 1991 fall meeting of the Low Level Radioactive Waste Forum. Topics included legal updates; US NRC updates; US EPA updates; mixed waste issues; financial assistance for waste disposal facilities; and a legislative and policy report

  2. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1993-01-01

    This paper provides the results of the winter meeting of the Low Level Radioactive Waste Forum. Discussions were held on the following topics: new developments in states and compacts; adjudicatory hearings; information exchange on siting processes, storage surcharge rebates; disposal after 1992; interregional access agreements; and future tracking and management issues

  3. Proceedings of a national food irradiation forum

    International Nuclear Information System (INIS)

    Van Noort, G.

    1989-01-01

    The proceedings of a national food irradiation forum are presented. The status of food radurization in South Africa is discussed in detail. Consumer attitudes to radurization are also looked at and the statutory control of food irradiation in South Africa is described

  4. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1992-01-01

    This paper provides highlights from the spring meeting of the Low Level Radioactive Waste Forum. Topics of discussion included: state and compact reports; New York's challenge to the constitutionality of the Low-Level Radioactive Waste Amendments Act of 1985; DOE technical assistance for 1993; interregional import/export agreements; Department of Transportation requirements; superfund liability; nonfuel bearing components; NRC residual radioactivity criteria

  5. The environmental communication forum | Goetz | Southern African ...

    African Journals Online (AJOL)

    The establishment, Modus operandi and aims of the Environmental Communicators Forum in the greater Durban area is described. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · Creative Commons License This work is licensed under a Creative ...

  6. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-12-31

    This paper provides highlights from the October 1990 meeting of the Low Level Radioactive Waste Forum. Topics of discussion included: a special session on liability and financial assurance needs; proposal to dispose of mixed waste at federal facilities; state plans for interim storage; and hazardous materials legislation.

  7. Authorship Analysis on Dark Marketplace Forums

    NARCIS (Netherlands)

    Spitters, M.; Klaver, F.; Koot, G.; Staalduinen, M.V.

    2015-01-01

    Anonymity networks like Tor harbor many underground markets and discussion forums dedicated to the trade of illegal goods and services. As they are gaining in popularity, the analysis of their content and users is becoming increasingly urgent for many different parties, ranging from law enforcement

  8. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This paper provides highlights from the 1995 summer meeting of the Low Level radioactive Waste Forum. Topics included: new developments in state and compacts; federal waste management; DOE plans for Greater-Than-Class C waste management; mixed wastes; commercial mixed waste management; international export of rad wastes for disposal; scintillation cocktails; license termination; pending legislation; federal radiation protection standards.

  9. Asian & Pacific Islander American Health Forum

    Science.gov (United States)

    ... Report.pdf [1.2MB] Obesity and Overweight Among Asian American Children and Adolescents 2016.04.28-OBESITY AND ... Month Stay Connected! Receive the latest APIAHF updates Asian & Pacific Islander American Health Forum. All rights reserved. One Kaiser Plaza, ...

  10. Low-level waste forum meeting reports

    International Nuclear Information System (INIS)

    1995-01-01

    This paper provides highlights from the 1995 summer meeting of the Low Level radioactive Waste Forum. Topics included: new developments in state and compacts; federal waste management; DOE plans for Greater-Than-Class C waste management; mixed wastes; commercial mixed waste management; international export of rad wastes for disposal; scintillation cocktails; license termination; pending legislation; federal radiation protection standards

  11. Facilitating Learning Spaces in Forum Theatre

    Science.gov (United States)

    Rae, Jan

    2013-01-01

    Purpose: The purpose of this paper is to evaluate the extent to which forum theatre interventions can support non-hierarchical approaches to learning, development and change management initiatives in organisations. Design/methodology/approach: Semi-structured interviews were carried out with theatre consultancies, actors/facilitators,…

  12. Public Participation Guide: Electronic Democracy

    Science.gov (United States)

    Electronic democracy describes a wide range of interactive tools that embrace existing and emergent media sources as a forum for allowing members of the public to express opinions and seek to influence decision-making.

  13. 78 FR 19024 - Lithium Ion Batteries in Transportation Public Forum

    Science.gov (United States)

    2013-03-28

    ... NATIONAL TRANSPORTATION SAFETY BOARD Lithium Ion Batteries in Transportation Public Forum On Thursday and Friday, April 11-12, 2013, the National Transportation Safety Board (NTSB) will convene a forum titled, ``Lithium Ion Batteries in Transportation.'' The forum will begin at 9:00 a.m. on both...

  14. Finding Question-Answer Pairs from Online Forums

    DEFF Research Database (Denmark)

    Cong, Gao; Wang, Long; Lin, Chin-Yew

    2008-01-01

    Online forums contain a huge amount of valuable user generated content. In this paper we address the problem of extracting question-answer pairs from forums. Question-answer pairs extracted from forums can be used to help Question Answering services (e.g. Yahoo! Answers) among other applications...

  15. 76 FR 71081 - Public Aircraft Oversight Safety Forum

    Science.gov (United States)

    2011-11-16

    ... NATIONAL TRANSPORTATION SAFETY BOARD Public Aircraft Oversight Safety Forum The National Transportation Safety Board (NTSB) will convene a Public Aircraft Oversight Safety Forum which will begin at 9 a... ``Public Aircraft Oversight Forum: Ensuring Safety for Critical Missions'', are to (1) raise awareness of...

  16. Characterization of Cardiac Time Intervals in Healthy Bonnet Macaques (Macaca radiata) by Using an Electronic Stethoscope

    Science.gov (United States)

    Kamran, Haroon; Salciccioli, Louis; Pushilin, Sergei; Kumar, Paraag; Carter, John; Kuo, John; Novotney, Carol; Lazar, Jason M

    2011-01-01

    Nonhuman primates are used frequently in cardiovascular research. Cardiac time intervals derived by phonocardiography have long been used to assess left ventricular function. Electronic stethoscopes are simple low-cost systems that display heart sound signals. We assessed the use of an electronic stethoscope to measure cardiac time intervals in 48 healthy bonnet macaques (age, 8 ± 5 y) based on recorded heart sounds. Technically adequate recordings were obtained from all animals and required 1.5 ± 1.3 min. The following cardiac time intervals were determined by simultaneously recording acoustic and single-lead electrocardiographic data: electromechanical activation time (QS1), electromechanical systole (QS2), the time interval between the first and second heart sounds (S1S2), and the time interval between the second and first sounds (S2S1). QS2 was correlated with heart rate, mean arterial pressure, diastolic blood pressure, and left ventricular ejection time determined by using echocardiography. S1S2 correlated with heart rate, mean arterial pressure, diastolic blood pressure, left ventricular ejection time, and age. S2S1 correlated with heart rate, mean arterial pressure, diastolic blood pressure, systolic blood pressure, and left ventricular ejection time. QS1 did not correlate with any anthropometric or echocardiographic parameter. The relation S1S2/S2S1 correlated with systolic blood pressure. On multivariate analyses, heart rate was the only independent predictor of QS2, S1S2, and S2S1. In conclusion, determination of cardiac time intervals is feasible and reproducible by using an electrical stethoscope in nonhuman primates. Heart rate is a major determinant of QS2, S1S2, and S2S1 but not QS1; regression equations for reference values for cardiac time intervals in bonnet macaques are provided. PMID:21439218

  17. Demonstration of fundamental statistics by studying timing of electronics signals in a physics-based laboratory

    Science.gov (United States)

    Beach, Shaun E.; Semkow, Thomas M.; Remling, David J.; Bradt, Clayton J.

    2017-07-01

    We have developed accessible methods to demonstrate fundamental statistics in several phenomena, in the context of teaching electronic signal processing in a physics-based college-level curriculum. A relationship between the exponential time-interval distribution and Poisson counting distribution for a Markov process with constant rate is derived in a novel way and demonstrated using nuclear counting. Negative binomial statistics is demonstrated as a model for overdispersion and justified by the effect of electronic noise in nuclear counting. The statistics of digital packets on a computer network are shown to be compatible with the fractal-point stochastic process leading to a power-law as well as generalized inverse Gaussian density distributions of time intervals between packets.

  18. Measurements of Electron Transport in Foils Irradiated with a Picosecond Time Scale Laser Pulse

    International Nuclear Information System (INIS)

    Brown, C. R. D.; Hoarty, D. J.; James, S. F.; Swatton, D.; Hughes, S. J.; Morton, J. W.; Guymer, T. M.; Hill, M. P.; Chapman, D. A.; Andrew, J. E.; Comley, A. J.; Shepherd, R.; Dunn, J.; Chen, H.; Schneider, M.; Brown, G.; Beiersdorfer, P.; Emig, J.

    2011-01-01

    The heating of solid foils by a picosecond time scale laser pulse has been studied by using x-ray emission spectroscopy. The target material was plastic foil with a buried layer of a spectroscopic tracer material. The laser pulse length was either 0.5 or 2 ps, which resulted in a laser irradiance that varied over the range 10 16 -10 19 W/cm 2 . Time-resolved measurements of the buried layer emission spectra using an ultrafast x-ray streak camera were used to infer the density and temperature conditions as a function of laser parameters and depth of the buried layer. Comparison of the data to different models of electron transport showed that they are consistent with a model of electron transport that predicts the bulk of the target heating is due to return currents.

  19. Compensating Unknown Time-Varying Delay in Opto-Electronic Platform Tracking Servo System

    Directory of Open Access Journals (Sweden)

    Ruihong Xie

    2017-05-01

    Full Text Available This paper investigates the problem of compensating miss-distance delay in opto-electronic platform tracking servo system. According to the characteristic of LOS (light-of-sight motion, we setup the Markovian process model and compensate this unknown time-varying delay by feed-forward forecasting controller based on robust H∞ control. Finally, simulation based on double closed-loop PI (Proportion Integration control system indicates that the proposed method is effective for compensating unknown time-varying delay. Tracking experiments on the opto-electronic platform indicate that RMS (root-mean-square error is 1.253 mrad when tracking 10° 0.2 Hz signal.

  20. INFLUENCE OF INCUBATION TIME, GAMMA RAYS AND ELECTRON BEAM ON RADIATION RESISTANCE OF SOME SELECTED PATHOGENS

    International Nuclear Information System (INIS)

    EL-HIFNAWI, H.N.; EL-TABLAWY, S.Y.

    2009-01-01

    The effect of different growth phases on the radiation resistance, antibiotic susceptibility and pathogenicity of certain selected pathogens (Escherichia coli, Candida albicans and Staphylococcus aureus) was studied in mice. The obtained results showed that Escherichia coli was slightly more resistant to gamma radiation in 18 h than 24 h or 48 h but it was relatively more resistant to electron beam in 24 h and 48 h than 18 h. Candida albicans showed radiation resistance nearly the same in all incubation times in the case of gamma radiation while for electron beam, its radiation resistance was slightly more in 24 h and 48 h than in 18 h. On the other hand, Staphylococcus aureus recorded much more resistance to gamma radiation in the 48 h than in 24 h or 18 h whereas in the case of electron beam, it was slightly more resistant in 18 h than in 24 h and 48 h.The antibiotic susceptibility of Escherichia coli reported that the exposure to gamma radiation at 3 kGy and electron beam at 6 kGy increase the susceptibility to the nalidixic acid and nitrofurantoin. When Candida albicans was exposed to 3 kGy gamma radiation and 6 kGy electron beam, the same sensitivity to nystatin was observed in comparison with the unexposed one while the sensitivity of Staphylococcus aureus to some antibiotics (amoxicillin, nitrofurantoin and tetracycline) was decreased after exposure to gamma radiation at 0.75 and 2 kGy and electron beam at 6 kGy, but for other antibiotics (trimethoprim/ sulfamethoxazole), the sensitivity was increased at 6 kGy electron beam.The lethality percent recorded after the oral ingestion of the mice with the unexposed Escherichia coli and Candida albicans were 25% and 100%, respectively, and for 6 kGy exposure to electron beam was 0% . The cotaneous disease and abscesses caused by the intradermal injection of the mice with unexposed Staphylococcus aureus was 75% and for 6 kGy exposure to electron beam was 25%.

  1. Consumer Electronics Processors for Critical Real-Time Systems: a (Failed) Practical Experience

    OpenAIRE

    Fernandez , Gabriel; Cazorla , Francisco; Abella , Jaume

    2018-01-01

    International audience; The convergence between consumer electronics and critical real-time markets has increased the need for hardware platforms able to deliver high performance as well as high (sustainable) performance guarantees. Using the ARM big.LITTLE architecture as example of those platforms, in this paper we report our experience with one of its implementations (the Qualcomm SnapDragon 810 processor) to derive performance bounds with measurement-based techniques. Our theoretical and ...

  2. Optimal Consumer Electronics Product Take-Back Time with Consideration of Consumer Value

    Directory of Open Access Journals (Sweden)

    Yi-Tse Fang

    2017-03-01

    Full Text Available Rapid economic growth in recent years has transformed our lifestyle to massively produce, consume, and dispose of products, especially for consumer electronics. This change has put great threat to our environment and caused natural resource depletion. Moreover, short product life cycles and quick replacements of consumer electronics create enormous electronic wastes (e-wastes. Without proper waste management, immense environmental damage is expected. In this empirical study, we notice that lots of valuable materials that can still be recycled from these used consumer electronics are left unused at home instead of being recycled at the appropriate time, which causes a low collection rate and a decrease in residual value for the used products. Therefore, it is important for the government and the recyclers to handle them efficiently by increasing the used product take-back rate. Our study develops an assessment model for customer value based on the idea of value engineering and the perspective of product life cycle. We also explore the relationship between product value and the total cost of ownership with an evaluation of their time variation, considering different usage modes for various consumer groups and different recycling award schemes (fixed and variable recycling awards. Proper take-back management is likely to create a win-win situation both for consumers and environmental protection. This study regards the notebook computer as an example to determine the optimal time for recycling laptops based on usage patterns and provides consumers a reference for when to replace their used product. The results from our modeling firstly clearly indicate that consumers with higher frequency of usage have shorter take back times and higher maximum consumer value. Secondly, a variable recycling award scheme with higher maximum consumer value is more practical than a fixed recycling award scheme.

  3. Quasi Real Time Data Analysis for Air Quality Monitoring with an Electronic Nose

    Science.gov (United States)

    Zhou, Hanying; Shevade, Abhijit V.; Pelletier, Christine C.; Homer, Margie L.; Ryan, M. Amy

    2006-01-01

    Cabin Air Quality Monitoring: A) Functions; 1) Incident monitor for targeted contaminants exceeding targeted concentrations. Identify and quantify. 2) Monitor for presence of compounds associated with fires or overheating electronics. 3) Monitor clean-up process. B) Characteristics; 1) Low mass, low power device. 2) Requires little crew time for maintenance and calibration. 3) Detects, identifies and quantifies selected chemical species at or below 24 hour SMAC.

  4. Real-Time Electronic Dashboard Technology and Its Use to Improve Pediatric Radiology Workflow.

    Science.gov (United States)

    Shailam, Randheer; Botwin, Ariel; Stout, Markus; Gee, Michael S

    The purpose of our study was to create a real-time electronic dashboard in the pediatric radiology reading room providing a visual display of updated information regarding scheduled and in-progress radiology examinations that could help radiologists to improve clinical workflow and efficiency. To accomplish this, a script was set up to automatically send real-time HL7 messages from the radiology information system (Epic Systems, Verona, WI) to an Iguana Interface engine, with relevant data regarding examinations stored in an SQL Server database for visual display on the dashboard. Implementation of an electronic dashboard in the reading room of a pediatric radiology academic practice has led to several improvements in clinical workflow, including decreasing the time interval for radiologist protocol entry for computed tomography or magnetic resonance imaging examinations as well as fewer telephone calls related to unprotocoled examinations. Other advantages include enhanced ability of radiologists to anticipate and attend to examinations requiring radiologist monitoring or scanning, as well as to work with technologists and operations managers to optimize scheduling in radiology resources. We foresee increased utilization of electronic dashboard technology in the future as a method to improve radiology workflow and quality of patient care. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Real-time evaluation of electron and current density profile parameters on TEXTOR

    International Nuclear Information System (INIS)

    Bruessau, W.D.; Soltwisch, H.

    1985-08-01

    The shapes of electron and current density profiles are monitored in real-time mode in order to get rapid qualitative information on the development of a TEXTOR tokamak plasma. The profiles are described by form parameters which relate to the signals of a 9-channel FIR-polari/interferometer in simple mathematical formulae. These profile parameters are obtained by real-time conversion of measured quantities for display on a storage oscilloscope or on a chart recorder. The application of the parameters is demonstrated in some examples. (orig.)

  6. Hot-electron-assisted femtochemistry at surfaces: A time-dependent density functional theory approach

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Rubio, Angel; Olsen, Thomas

    2009-01-01

    Using time-evolution time-dependent density functional theory (TDDFT) within the adiabatic local-density approximation, we study the interactions between single electrons and molecular resonances at surfaces. Our system is a nitrogen molecule adsorbed on a ruthenium surface. The surface is modele...... resonance and the lowering of the resonance energy due to an image charge effect. Finally we apply the TDDFT procedure to only consider the decay of molecular excitations and find that it agrees quite well with the width of the projected density of Kohn-Sham states....

  7. Real-time simulator for designing electron dual scattering foil systems.

    Science.gov (United States)

    Carver, Robert L; Hogstrom, Kenneth R; Price, Michael J; LeBlanc, Justin D; Pitcher, Garrett M

    2014-11-08

    The purpose of this work was to develop a user friendly, accurate, real-time com- puter simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator allows for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator also is a powerful educational tool. The simulator consists of an analytical algorithm for calculating electron fluence and X-ray dose and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with the reduced Gaussian formalism for scattering powers. The simulator also estimates central-axis and off-axis X-ray dose arising from the dual foil system. Once the geometry of the accelerator is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scat- tering foil material and Gaussian shape (thickness and sigma), and beam energy. The off-axis electron relative fluence or total dose profile and central-axis X-ray dose contamination are computed and displayed in real time. The simulator was validated by comparison of off-axis electron relative fluence and X-ray percent dose profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV, using present foils on an Elekta radiotherapy accelerator, the simulator was able to reproduce MC profiles to within 2% out to 20 cm from the central axis. The central-axis X-ray percent dose predictions matched measured data to within 0.5%. The calculation time was approximately 100 ms using a single Intel 2.93 GHz processor, which allows for real-time variation of foil geometrical parameters using slider bars. This work demonstrates how the user-friendly GUI and real-time nature of the simulator make it an effective educational tool for gaining a better understanding of the effects that various system

  8. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    International Nuclear Information System (INIS)

    Zaheer, S.; Yoon, P. H.

    2013-01-01

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the κ distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized κ distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index α, where f e ∼ v –α is close to the average index observed during the quiet-time solar wind condition, i.e., α ∼ O(6.5) whereas α average ∼ 6.69, according to observation

  9. Real-Time Digital Signal Processing Based on FPGAs for Electronic Skin Implementation †

    Directory of Open Access Journals (Sweden)

    Ali Ibrahim

    2017-03-01

    Full Text Available Enabling touch-sensing capability would help appliances understand interaction behaviors with their surroundings. Many recent studies are focusing on the development of electronic skin because of its necessity in various application domains, namely autonomous artificial intelligence (e.g., robots, biomedical instrumentation, and replacement prosthetic devices. An essential task of the electronic skin system is to locally process the tactile data and send structured information either to mimic human skin or to respond to the application demands. The electronic skin must be fabricated together with an embedded electronic system which has the role of acquiring the tactile data, processing, and extracting structured information. On the other hand, processing tactile data requires efficient methods to extract meaningful information from raw sensor data. Machine learning represents an effective method for data analysis in many domains: it has recently demonstrated its effectiveness in processing tactile sensor data. In this framework, this paper presents the implementation of digital signal processing based on FPGAs for tactile data processing. It provides the implementation of a tensorial kernel function for a machine learning approach. Implementation results are assessed by highlighting the FPGA resource utilization and power consumption. Results demonstrate the feasibility of the proposed implementation when real-time classification of input touch modalities are targeted.

  10. Time-gated scintillator imaging for real-time optical surface dosimetry in total skin electron therapy

    Science.gov (United States)

    Bruza, Petr; Gollub, Sarah L.; Andreozzi, Jacqueline M.; Tendler, Irwin I.; Williams, Benjamin B.; Jarvis, Lesley A.; Gladstone, David J.; Pogue, Brian W.

    2018-05-01

    The purpose of this study was to measure surface dose by remote time-gated imaging of plastic scintillators. A novel technique for time-gated, intensified camera imaging of scintillator emission was demonstrated, and key parameters influencing the signal were analyzed, including distance, angle and thickness. A set of scintillator samples was calibrated by using thermo-luminescence detector response as reference. Examples of use in total skin electron therapy are described. The data showed excellent room light rejection (signal-to-noise ratio of scintillation SNR  ≈  470), ideal scintillation dose response linearity, and 2% dose rate error. Individual sample scintillation response varied by 7% due to sample preparation. Inverse square distance dependence correction and lens throughput error (8% per meter) correction were needed. At scintillator-to-source angle and observation angle  <50°, the radiant energy fluence error was smaller than 1%. The achieved standard error of the scintillator cumulative dose measurement compared to the TLD dose was 5%. The results from this proof-of-concept study documented the first use of small scintillator targets for remote surface dosimetry in ambient room lighting. The measured dose accuracy renders our method to be comparable to thermo-luminescent detector dosimetry, with the ultimate realization of accuracy likely to be better than shown here. Once optimized, this approach to remote dosimetry may substantially reduce the time and effort required for surface dosimetry.

  11. Modeling molecule-plasmon interactions using quantized radiation fields within time-dependent electronic structure theory

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Daniel R.; DePrince, A. Eugene, E-mail: deprince@chem.fsu.edu [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390 (United States)

    2015-12-07

    We present a combined cavity quantum electrodynamics/ab initio electronic structure approach for simulating plasmon-molecule interactions in the time domain. The simple Jaynes-Cummings-type model Hamiltonian typically utilized in such simulations is replaced with one in which the molecular component of the coupled system is treated in a fully ab initio way, resulting in a computationally efficient description of general plasmon-molecule interactions. Mutual polarization effects are easily incorporated within a standard ground-state Hartree-Fock computation, and time-dependent simulations carry the same formal computational scaling as real-time time-dependent Hartree-Fock theory. As a proof of principle, we apply this generalized method to the emergence of a Fano-like resonance in coupled molecule-plasmon systems; this feature is quite sensitive to the nanoparticle-molecule separation and the orientation of the molecule relative to the polarization of the external electric field.

  12. Electronics for a Next-Generation SQUID-Based Time-Domain Multiplexing System

    International Nuclear Information System (INIS)

    Reintsema, C. D.; Doriese, W. R.; Hilton, G. C.; Irwin, K. D.; Krinsky, J. W.; Adams, J. S.; Baker, R.; Bandler, S. R.; Kelly, R. L.; Kilbourne, C. A.; Porter, F. S.; Figueroa-Feliciano, E.; Wikus, P.

    2009-01-01

    A decade has elapsed since the design, development and realization of a SQUID-based time-division multiplexer at NIST. During this time the system has been used extensively for low-temperature-detector-array measurements. Concurrently, there have been substantial advancements both in detector array and commercial electronic component technology. The relevance and applicability of the technology has blossomed as well, often accompanied by more demanding measurement requirements. These factors have motivated a complete redesign of the NIST room-temperature read-out electronics. The redesign has leveraged advancements in component technology to achieve new capabilities better suited to the SQUID multiplexers and detector arrays being realized today. As examples of specific performance enhancements, the overall system bandwidth has been increased by a factor of four (a row switching rate of 6.24 MHz), the compactness has been increased by over a factor of two (a higher number of detector columns and rows per circuit board), and there are two high speed outputs per column (allowing fast switching of SQUID offsets in addition to digital feedback). The system architecture, design implementations, and performance advantages of the new system will be discussed. As an application example, the science chain flight electronics for the Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket will be described as both a motivation for, and a direct implementation of the new system.

  13. The boomerang effect in electron-hydrogen molecule scattering as determined by time-dependent calculations

    Science.gov (United States)

    Ben-Asher, Anael; Moiseyev, Nimrod

    2017-05-01

    The appearance of oscillations in the energy-dependent cross sections of the vibrational excitation ν =0 →ν ≥3 of the hydrogen molecule in its electronic ground state as predicted by Mündel, Berman, and Domcke [Phys. Rev. A 32, 181 (1985)] was confirmed in the electron scattering experiments by Allan [J. Phys. B: At. Mol. Phys. 18, L451 (1985)]. These unusual structures were obtained in spite of the extremely short lifetime of H2- in its ro-vibrational states. Based on the standard (Hermitian) time-independent scattering calculations, Horáček et al. [Phys. Rev. A 73, 022701 (2006)] associated these oscillations with the boomerang effect. Here, we show the boomerang effect as developed in time, based on our time-dependent nuclear wavepacket (WP) calculations. The nuclear WP dynamics of H2- is determined using the non-Hermitian quantum mechanics (NH-QM) which enables the use of the Born-Oppenheimer approximation with complex potential energy surfaces. This NH-QM approach, which enables us the association of the nuclear WP dynamics as obtained from the complex potential energy curve of H2- with the evolution of cross section in time, can enlighten the dynamics in other scattering experiments.

  14. Real-time observation of intersystem crossing induced by charge recombination during bimolecular electron transfer reactions

    KAUST Repository

    Alsam, Amani Abdu

    2016-09-21

    Real-time probing of intersystem crossing (ISC) and triplet-state formation after photoinduced electron transfer (ET) is a particularly challenging task that can be achieved by time-resolved spectroscopy with broadband capability. Here, we examine the mechanism of charge separation (CS), charge recombination (CR) and ISC of bimolecular photoinduced electron transfer (PET) between poly[(9,9-di(3,3′-N,N’-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctyl-fluorenyl-2,7-diyl)] diiodide salt (PFN) and dicyanobenzene (DCB) using time-resolved spectroscopy. PET from PFN to DCB is confirmed by monitoring the transient absorption (TA) and infrared spectroscopic signatures for the radical ion pair (DCB─•-PFN+•). In addition, our time-resolved results clearly demonstrate that CS takes place within picoseconds followed by CR within nanoseconds. The ns-TA data exhibit the clear spectroscopic signature of PFN triplet-triplet absorption, induced by the CR of the radical ion pairs (DCB─•-PFN+•). As a result, the triplet state of PFN (3PFN*) forms and subsequently, the ground singlet state is replenished within microseconds. © 2016

  15. Electron-impact ionization of oriented molecules using the time-dependent close-coupling approach

    Energy Technology Data Exchange (ETDEWEB)

    Colgan, J [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Pindzola, M S, E-mail: jcolgan@lanl.gov [Department of Physics, Auburn University, Auburn, AL 36849 (United States)

    2011-04-01

    An overview is given on recent progress on computing triple differential cross sections for electron-impact ionization of the hydrogen molecule using a time-dependent close-coupling approach. Our calculations, when averaged over all molecular orientations, are generally in very good agreement with (e,2e) measurements made on H{sub 2}, where the molecular orientation is unknown, for a range of incident energies and outgoing electron angles and energies. In this paper, we present TDCS for ionization of H{sub 2} at specific molecular orientations. It is hoped that this study will help stimulate future measurements of TDCS from oriented H{sub 2} at medium impact energies.

  16. Study on time of flight property of electron optical systems by differential algebraic method

    International Nuclear Information System (INIS)

    Cheng Min; Tang Tiantong; Yao Zhenhua

    2002-01-01

    Differential algebraic method is a powerful and promising technique in computer numerical analysis. When applied to nonlinear dynamics systems, the arbitrary high-order transfer properties of the systems can be computed directly with high precision. In this paper, the principle of differential algebra is applied to study on the time of flight (TOF) property of electron optical systems and their arbitrary order TOF transfer properties can be numerically calculated out. As an example, TOF transfer properties of a uniform magnetic sector field analyzer have been studied by differential algebraic method. Relative errors of the first-order and second-order TOF transfer coefficients of the magnetic sector field analyzer are of the order 10 -11 or smaller compared with the analytic solutions. It is proved that differential algebraic TOF method is of high accuracy and very helpful for high-order TOF transfer property analysis of electron optical systems. (author)

  17. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.; Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-12-31

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  18. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 [mu]s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  19. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States)); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  20. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States); Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-09-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  1. Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields.

    Science.gov (United States)

    Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin; Sahni, Viraht

    2014-01-14

    We derive via the interaction "representation" the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field-the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement - the uniform electron gas - the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.

  2. Time-dependence hole and electron trapping effects in SIMOX buried oxides

    International Nuclear Information System (INIS)

    Boesch, H.E. Jr.; Taylor, T.L.; Hite, L.R.; Bailey, W.E.

    1990-01-01

    Back-channel threshold shift associated with the buried oxide layers of separation by implanted oxygen (SIMOX) and zone-melted recrystallization (ZMR) field-effect transistors (FETs) was measured following pulsed irradiation as a function of temperature and back-gate bias using a fast time-resolved I-V measurement technique. The SIMOX FETs showed large initial negative voltage shifts at 0.2 ms after irradiation followed by temperature- and bias-dependent additional negative shifts to 800s. Analysis and modeling of the results indicate efficient deep trapping of radiation-generated holes in the bulk of the oxide, substantial initial trapping of radiation-generated electrons in the oxide, and rapid removal of the trapped electrons by a thermal detrapping process. The ZMR FETs showed evidence of substantial trapping of holes alone in the oxide bulk

  3. Pickup design for high bandwidth bunch arrival-time monitors in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf [TU Darmstadt (Germany). Institut fuer Mikrowellentechnik und Photonik; Kuhl, Alexander; Schnepp, Sascha [TU Darmstadt (Germany). Graduate School of Computational Engineering; Bock, Marie Kristin; Bousonville, Michael; Schlarb, Holger [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Weiland, Thomas [TU Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder

    2012-07-01

    The increased demands for low bunch charge operation mode in the free-electron lasers (FELs) require an upgrade of the existing synchronization equipment. As a part of the laser-based synchronization system, the bunch arrival-time monitors (BAMs) should have a sub-10 femtosecond precision for high and low bunch charge operation. In order to fulfill the resolution demands for both modes of operation, the bandwidth of such a BAM should be increased up to a cutoff frequency of 40 GHz. In this talk, we present the design and the realization of high bandwidth cone-shaped pickup electrodes as a part of the BAM for the FEL in Hamburg (FLASH) and the European X-ray free-electron laser (European XFEL). The proposed pickup was simulated with CST STUDIO SUITE, and a non-hermetic model was built up for radio frequency (rf) measurements.

  4. Geometrical effects on the electron residence time in semiconductor nano-particles.

    Science.gov (United States)

    Koochi, Hakimeh; Ebrahimi, Fatemeh

    2014-09-07

    We have used random walk (RW) numerical simulations to investigate the influence of the geometry on the statistics of the electron residence time τ(r) in a trap-limited diffusion process through semiconductor nano-particles. This is an important parameter in coarse-grained modeling of charge carrier transport in nano-structured semiconductor films. The traps have been distributed randomly on the surface (r(2) model) or through the whole particle (r(3) model) with a specified density. The trap energies have been taken from an exponential distribution and the traps release time is assumed to be a stochastic variable. We have carried out (RW) simulations to study the effect of coordination number, the spatial arrangement of the neighbors and the size of nano-particles on the statistics of τ(r). It has been observed that by increasing the coordination number n, the average value of electron residence time, τ̅(r) rapidly decreases to an asymptotic value. For a fixed coordination number n, the electron's mean residence time does not depend on the neighbors' spatial arrangement. In other words, τ̅(r) is a porosity-dependence, local parameter which generally varies remarkably from site to site, unless we are dealing with highly ordered structures. We have also examined the effect of nano-particle size d on the statistical behavior of τ̅(r). Our simulations indicate that for volume distribution of traps, τ̅(r) scales as d(2). For a surface distribution of traps τ(r) increases almost linearly with d. This leads to the prediction of a linear dependence of the diffusion coefficient D on the particle size d in ordered structures or random structures above the critical concentration which is in accordance with experimental observations.

  5. Real-time fault diagnosis and fault-tolerant control

    OpenAIRE

    Gao, Zhiwei; Ding, Steven X.; Cecati, Carlo

    2015-01-01

    This "Special Section on Real-Time Fault Diagnosis and Fault-Tolerant Control" of the IEEE Transactions on Industrial Electronics is motivated to provide a forum for academic and industrial communities to report recent theoretic/application results in real-time monitoring, diagnosis, and fault-tolerant design, and exchange the ideas about the emerging research direction in this field. Twenty-three papers were eventually selected through a strict peer-reviewed procedure, which represent the mo...

  6. What Online Communities Can Tell Us About Electronic Cigarettes and Hookah Use: A Study Using Text Mining and Visualization Techniques.

    Science.gov (United States)

    Chen, Annie T; Zhu, Shu-Hong; Conway, Mike

    2015-09-29

    The rise in popularity of electronic cigarettes (e-cigarettes) and hookah over recent years has been accompanied by some confusion and uncertainty regarding the development of an appropriate regulatory response towards these emerging products. Mining online discussion content can lead to insights into people's experiences, which can in turn further our knowledge of how to address potential health implications. In this work, we take a novel approach to understanding the use and appeal of these emerging products by applying text mining techniques to compare consumer experiences across discussion forums. This study examined content from the websites Vapor Talk, Hookah Forum, and Reddit to understand people's experiences with different tobacco products. Our investigation involves three parts. First, we identified contextual factors that inform our understanding of tobacco use behaviors, such as setting, time, social relationships, and sensory experience, and compared the forums to identify the ones where content on these factors is most common. Second, we compared how the tobacco use experience differs with combustible cigarettes and e-cigarettes. Third, we investigated differences between e-cigarette and hookah use. In the first part of our study, we employed a lexicon-based extraction approach to estimate prevalence of contextual factors, and then we generated a heat map based on these estimates to compare the forums. In the second and third parts of the study, we employed a text mining technique called topic modeling to identify important topics and then developed a visualization, Topic Bars, to compare topic coverage across forums. In the first part of the study, we identified two forums, Vapor Talk Health & Safety and the Stopsmoking subreddit, where discussion concerning contextual factors was particularly common. The second part showed that the discussion in Vapor Talk Health & Safety focused on symptoms and comparisons of combustible cigarettes and e

  7. An atomic orbital based real-time time-dependent density functional theory for computing electronic circular dichroism band spectra

    Energy Technology Data Exchange (ETDEWEB)

    Goings, Joshua J.; Li, Xiaosong, E-mail: xsli@uw.edu [Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States)

    2016-06-21

    One of the challenges of interpreting electronic circular dichroism (ECD) band spectra is that different states may have different rotatory strength signs, determined by their absolute configuration. If the states are closely spaced and opposite in sign, observed transitions may be washed out by nearby states, unlike absorption spectra where transitions are always positive additive. To accurately compute ECD bands, it is necessary to compute a large number of excited states, which may be prohibitively costly if one uses the linear-response time-dependent density functional theory (TDDFT) framework. Here we implement a real-time, atomic-orbital based TDDFT method for computing the entire ECD spectrum simultaneously. The method is advantageous for large systems with a high density of states. In contrast to previous implementations based on real-space grids, the method is variational, independent of nuclear orientation, and does not rely on pseudopotential approximations, making it suitable for computation of chiroptical properties well into the X-ray regime.

  8. Forum Engelberg, 1-4 March 2004

    CERN Document Server

    2004-01-01

    The 2004 Forum Engelberg will pay tribute to its President, Hubert Curien, a former President of the CERN Council and former French Minister for Research. The subject of this year's conference, which will take place in Lucerne from 1st to 4th March 2004, is "Science on the Agenda of European Politics." This year, there will be talks by numerous speakers, including the directors of the seven European intergovernmental scientific organisations (EIROforum) and the European Commissioner for Research, Philippe Busquin. The highlights of the conference will include an Interdisciplinary Scientific Programme on 2nd and 3rd March, a session on e-science and the Grid on 4th March and a Young Scientists Programme. The programme and registration forms are available at http://www.forum-engelberg.org/

  9. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President, Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996 - is pictured here. Photo 01: Hubert Curien in front of the first half of the CMS detector's barrel hadronic calorimeter (HCAL). The barrel HCAL is a cylindrical structure which will surround the collision region and measure the energy of quarks and jets emerging at large angles relative to the beam direction. Photo 02: Hubert Curien (left) with Bernard Ecoffey, Founder of the Forum Engelberg, in front of the first half of the CMS detector's barrel hadronic calorimeter.

  10. Forum on specification and Design Languages

    CERN Document Server

    Maehne, Torsten

    2015-01-01

    This book brings together a selection of the best papers from the sixteenth edition of the Forum on specification and Design Languages Conference (FDL), which was held in September 2013 in Paris, France. FDL is a well-established international forum devoted to dissemination of research results, practical experiences and new ideas in the application of specification, design and verification languages to the design, modeling and verification of integrated circuits, complex hardware/software embedded systems, and mixed-technology systems. • Covers applications of formal methods for specification, verification and debug; • Includes embedded analog and mixed-signal system design; • Enables model-driven engineering for embedded systems design and development.

  11. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. He is pictured here (centre) with (left to right) Raymond Battistella, Director-General of SIG, Geneva's utilities provider; Michel Della Negra; Marie-Anne Heimo; Jean-Claude Landry; and Bernard Ecoffey, Founder of the Forum Engelberg, in front of the CMS detector under construction. Visible are three of the five concentric rings forming the barrel yoke which returns the magnetic flux generated by the superconducting coil.

  12. Drift chamber electronics with multi-hit capability for time and current division measurements

    Energy Technology Data Exchange (ETDEWEB)

    Manarin, A; Pregernig, L; Rabany, M; Saban, R; Vismara, G

    1983-11-15

    Drift chambers have been installed for luminosity measurements in intersection 5 of the SPS accelerator working in panti p colliding mode. The required electronics is described. The system is able to process up to 16 hits per wire with a double pulse resolution of 40 ns; drift time and current division, with 1.25 ns and 1.6% resolution respectively, are recorded. Transconductance preamplifiers and discriminators are directly mounted on the chamber; 160 m of twisted-apir cable bring the signals to the digitizer unit. Coarse time is measured using RAM techniques, while fine time is obtained by means of a microstrip delay associated with a 100 K ECL priority encoder. Current division used a single 50 MHz Flash ADC which alows 26 dB dynamic range with 6 bit resolution. First operational results are reported.

  13. Real-time beam tracing for control of the deposition location of electron cyclotron waves

    Energy Technology Data Exchange (ETDEWEB)

    Reich, M., E-mail: matthias.reich@ipp.mpg.de; Bilato, R.; Mszanowski, U.; Poli, E.; Rapson, C.; Stober, J.; Volpe, F.; Zille, R.

    2015-11-15

    Highlights: • We successfully integrated a real-time EC beam tracing code at ASDEX Upgrade. • The calculation of EC beam deposition location is fast enough for control purposes. • The accuracy of the deposition location calculation exceeds equivalent measurements. • The implementation method is by design portable to larger fusion devices. - Abstract: Plasma control techniques that use electron cyclotron (EC) resonance heating and current drive such as control of neoclassical tearing modes require accurate control of the deposition location of EC beams. ASDEX Upgrade has successfully implemented a real-time version of the beam-tracing code TORBEAM into its real-time diagnostic system to act as a globally available module that calculates current deposition location and its sensitivity from other real-time diagnostic measurements for all its moveable EC wave launchers. Based on a highly (100×) accelerated version of TORBEAM, the software implementation as a diagnostic process uses parallelization and achieves cycle times of 15–20 ms for determining the radial deposition location of 12 beams in the plasma. This cycle time includes data input–output overhead arising from the use of available real-time signals. The system is by design portable to other machines such as ITER.

  14. Empirical forecast of quiet time ionospheric Total Electron Content maps over Europe

    Science.gov (United States)

    Badeke, Ronny; Borries, Claudia; Hoque, Mainul M.; Minkwitz, David

    2018-06-01

    An accurate forecast of the atmospheric Total Electron Content (TEC) is helpful to investigate space weather influences on the ionosphere and technical applications like satellite-receiver radio links. The purpose of this work is to compare four empirical methods for a 24-h forecast of vertical TEC maps over Europe under geomagnetically quiet conditions. TEC map data are obtained from the Space Weather Application Center Ionosphere (SWACI) and the Universitat Politècnica de Catalunya (UPC). The time-series methods Standard Persistence Model (SPM), a 27 day median model (MediMod) and a Fourier Series Expansion are compared to maps for the entire year of 2015. As a representative of the climatological coefficient models the forecast performance of the Global Neustrelitz TEC model (NTCM-GL) is also investigated. Time periods of magnetic storms, which are identified with the Dst index, are excluded from the validation. By calculating the TEC values with the most recent maps, the time-series methods perform slightly better than the coefficient model NTCM-GL. The benefit of NTCM-GL is its independence on observational TEC data. Amongst the time-series methods mentioned, MediMod delivers the best overall performance regarding accuracy and data gap handling. Quiet-time SWACI maps can be forecasted accurately and in real-time by the MediMod time-series approach.

  15. Models for the transport of low energy electrons in water and the yield of hydrated electrons at early times

    International Nuclear Information System (INIS)

    Brenner, D.J.; Miller, J.H.; Ritchie, R.H.; Bichsel, H.

    1985-01-01

    An insulator model with four experimental energy bands was used to fit the optical properties of liquid water and to extend these data to non-zero momentum transfer. Inelastic mean free paths derived from this dielectric response function provided the basic information necessary to degrade high energy electrons to the subexcitation energy domain. Two approaches for the transport of subexcitation electrons were investigated. (i) Gas phase cross sections were used to degrade subexcitation electrons to thermal energy and the thermalization lengths were scaled to unit density. (ii) Thermalization lengths were estimated by age-diffusion theory with a stopping power deduced from the data on liquid water and transport cross sections derived from elastic scattering in water vapor. Theoretical ranges were compared to recent experimental results. A stochastic model was used to calculate the rapid diffusion and reaction of hydrated electrons with other radiolysis products. The sensitivity of the calculated yields to the model assumptions and comparison with experimental data are discussed

  16. Stigma of HIV Testing on Online HIV Forums: Self-Stigma and the Unspoken.

    Science.gov (United States)

    Ho, Chia-Ling Lynn; Pan, Wenjing; Taylor, Laramie D

    2017-12-01

    Most studies examining HIV-related content in web forums have revolved around the most frequently used terms in HIV-related messages and topics, as well as the supportive nature of those messages. The current study explored barriers that prevent individuals from seeking HIV testing (specifically stigma). The current study analyzed a total of 210 threads and 319 posts, yielding 13 threads that revealed how individuals self-stigmatize and expressed how the fear of being diagnosed prevented them from seeking HIV testing. Results suggest that forums or online communities may perpetuate subculture values that deviate from mainstream values. Another important finding is that there is a lack of HIV testing information in forums for adolescents, which may contribute to the trend of young individuals engaging in risky sexual behaviors not getting tested in a timely fashion. [Journal of Psychosocial Nursing and Mental Health Services, 55(12), 34-43.]. Copyright 2017, SLACK Incorporated.

  17. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. This series of photos was taken during a speech he made as part of a visit to CERN.

  18. Carbon doped PDMS: conductance stability over time and implications for additive manufacturing of stretchable electronics

    International Nuclear Information System (INIS)

    Tavakoli, Mahmoud; Rocha, Rui; Osorio, Luis; Almeida, Miguel; De Almeida, Anibal; Ramachandran, Vivek; Tabatabai, Arya; Lu, Tong; Majidi, Carmel

    2017-01-01

    Carbon doped PDMS (cPDMS), has been used as a conductive polymer for stretchable electronics. Compared to liquid metals, cPDMS is low cost and is easier to process or to print with an additive manufacturing process. However, changes on the conductance of the carbon based conductive PDMS (cPDMS) were observed over time, in particular after integration of cPDMS and the insulating polymer. In this article we investigate the process parameters that lead to improved stability over conductance of the cPDMS over time. Slight modifications to the fabrication process parameters were conducted and changes on the conductance of the samples for each method were monitored. Results suggested that change of the conductance happens mostly after integration of a pre-polymer over a cured cPDMS, and not after integration of the cPDMS over a cured insulating polymer. We show that such changes can be eliminated by adjusting the integration priority between the conductive and insulating polymers, by selecting the right curing temperature, changing the concentration of the carbon particles and the thickness of the conductive traces, and when possible by changing the insulating polymer material. In this way, we obtained important conclusions regarding the effect of these parameters on the change of the conductance over time, that should be considered for additive manufacturing of soft electronics. Also, we show that these changes can be possibly due to the diffusion from PDMS into cPDMS. (paper)

  19. Time-resolved magnetic imaging in an aberration-corrected, energy-filtered photoemission electron microscope

    International Nuclear Information System (INIS)

    Nickel, F.; Gottlob, D.M.; Krug, I.P.; Doganay, H.; Cramm, S.; Kaiser, A.M.; Lin, G.; Makarov, D.; Schmidt, O.G.

    2013-01-01

    We report on the implementation and usage of a synchrotron-based time-resolving operation mode in an aberration-corrected, energy-filtered photoemission electron microscope. The setup consists of a new type of sample holder, which enables fast magnetization reversal of the sample by sub-ns pulses of up to 10 mT. Within the sample holder current pulses are generated by a fast avalanche photo diode and transformed into magnetic fields by means of a microstrip line. For more efficient use of the synchrotron time structure, we developed an electrostatic deflection gating mechanism capable of beam blanking within a few nanoseconds. This allows us to operate the setup in the hybrid bunch mode of the storage ring facility, selecting one or several bright singular light pulses which are temporally well-separated from the normal high-intensity multibunch pulse pattern. - Highlights: • A new time-resolving operation mode in photoemission electron microscopy is shown. • Our setup works within an energy-filtered, aberration-corrected PEEM. • A new gating system for bunch selection using synchrotron radiation is developed. • An alternative magnetic excitation system is developed. • First tr-imaging using an energy-filtered, aberration-corrected PEEM is shown

  20. Opportunist combination of electronic technologies for real time calculations in the Tore Supra Tokamak

    International Nuclear Information System (INIS)

    Barbuti, A.; Gil, C.; Pastor, P.; Spuig, P.; Vincent, B.; Volpe, D.

    2013-06-01

    The Tore Supra tokamak real-time plasma control is based on measurements coming from various diagnostics. The complexity of all the events that occur during plasma is at the origin of measurements disturbances which have to be corrected in real time in order to ensure an optimal control. The signal correction does not just mean processing but requires complex algorithms. Electronics does not only need to process and adapt electrical signals, but it has to include corrections by mathematical calculation. The FPGA (field-programmable gate array) technology, with the help of basic adapted electronics, allows integrating the entire real time calculation and digital data transmission on the network. FMC (FPGA Mezzanine Card) coupled with in-house motherboard, which is used both as the interface with Tore Supra specific systems and as the support for other signals processing options, is the perfect answer to this request. The FMC includes a FPGA, memory, Ethernet port and multiple I/O for interfacing with the motherboard and Tore Supra signals. The algorithms are developed in VHDL (Very high speed integrated circuit Hardware Description Language), parallel process management that promotes faster calculation than a common μC (Micro-controller) in one clock pulse. The flexibility, the low cost and the implementation speed allow fitting a large number of various applications in fields where no 'off-theshelf' component can be found. And more specifically, in research and experimentation, algorithms can be continuously improved or modified for new requirements. (authors)

  1. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya

    2016-02-25

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  2. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya; Adhikari, Aniruddha; Shaheen, Basamat; Yang, Haoze; Mohammed, Omar F.

    2016-01-01

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  3. Exciplex formation in bimolecular photoinduced electron-transfer investigated by ultrafast time-resolved infrared spectroscopy.

    Science.gov (United States)

    Koch, Marius; Letrun, Romain; Vauthey, Eric

    2014-03-12

    The dynamics of bimolecular photoinduced electron-transfer reactions has been investigated with three donor/acceptor (D/A) pairs in tetrahydrofuran (THF) and acetonitrile (ACN) using a combination of ultrafast spectroscopic techniques, including time-resolved infrared absorption. For the D/A pairs with the highest driving force of electron transfer, all transient spectroscopic features can be unambiguously assigned to the excited reactant and the ionic products. For the pair with the lowest driving force, three additional transient infrared bands, more intense in THF than in ACN, with a time dependence that differs from those of the other bands are observed. From their frequency and solvent dependence, these bands can be assigned to an exciplex. Moreover, polarization-resolved measurements point to a relatively well-defined mutual orientation of the constituents and to a slower reorientational time compared to those of the individual reactants. Thanks to the minimal overlap of the infrared signature of all transient species in THF, a detailed reaction scheme including the relevant kinetic and thermodynamic parameters could be deduced for this pair. This analysis reveals that the formation and recombination of the ion pair occur almost exclusively via the exciplex.

  4. 2nd Developers@CERN Forum

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Are you a Python guru or would you like to learn?   The Developers@CERN Forum is an event by developers, for developers, aimed at promoting knowledge and experience sharing. This edition will take place at the IT Amphitheatre, on the 30th and 31st of May afternoons. It will consist of a series of short presentations and workshops. The topic for this conference will be Python at CERN: language, frameworks and tools. Have you got an idea for a presentation or workshop? Then, tell us about it (deadline on 9th of May). Registration will open in early May. Please subscribe to developers-forum-announce@cern.ch mailing list for further information. This event will be made by developers for developers. We are counting on your presence, but also on your contributions! To learn more about the initiative, read the CERN Bulletin article. Organization You can get in touch us at developers-forum-organizers@cern.ch.

  5. Dependence of the confinement time of an electron plasma on the magnetic field in a quadrupole Penning trap

    Energy Technology Data Exchange (ETDEWEB)

    Dyavappa, B.M.; Datar, Durgesh; Prakash; Ananthamurthy, Sharath [Bangalore University, Department of Physics, Bangalore (India)

    2017-12-15

    A quadrupole Penning trap is used to confine electrons in weak magnetic fields. Perturbations due to space charge and imperfections in the trap geometry, as well as collisions with the background gas molecules, lead to loss of the electrons from the trap. We present in this work the results on measurements of the electron confinement time and its dependence on the magnetic field in a quadrupolar Penning trap. We describe a method to measure the confinement time of an electron cloud under weak magnetic fields (0.01 T - 0.1 T). This time is found to scale as τ ∝ B{sup 1.41} in variance with the theoretically expected confinement time that scales as τ ∝ B{sup 2} for trapped electrons that are lost through collisions with the neutrals present in the trap. A measurement of the expansion rate of the electron plasma in the trap through controlled variation of the trap voltage, yields expansion times that depend on the energy of escaping electrons. This is found to vary in our case in the scaling range B{sup 0.32} to B{sup 0.43}. Distorting the geometry of the trap, results in a marked change in the confinement time's dependence on the magnetic field. The results indicate that the confinement time of the electron cloud in the trap is limited by both, effects of collisions and perturbations that result in the plasma loss through expansion in the trap. (orig.)

  6. Search for Time Reversal Violation in Neutron Decay: A Measurement of the Transverse Polarization of Electrons

    International Nuclear Information System (INIS)

    Bodek, K.; Kaczmarek, A.; Kistryn, St.; Kuzniak, M.; Zejma, J.; Pulut, J.; Kirch, K.; Bialek, A.; Kozela, A.; Ban, G.; Naviliat-Cuncic, O.; Gorel, P.; Beck, M.; Lindroth, A.; Severijns, N.; Stephan, E.; Czarnecki, A.

    2006-01-01

    A non-zero value of the R-correlation coefficient due to the e - polarization component, perpendicular to the plane spanned by the spin of the decaying neutron and the electron momentum, would signal a violation of time reversal symmetry and thus physics beyond the Standard Model. The value of the N-correlation coefficient, given by the transverse e - polarization component within that plane, is expected to be finite. The measurement of N serves as an important systematic check of the apparatus for the R-measurement. The first phase of data taking has been completed. Preliminary results from a limited data sample show no deviations from the Standard Model predictions

  7. Development of a time projection chamber using gas electron multipliers (GEM-TPC)

    International Nuclear Information System (INIS)

    Oda, S.X.; Hamagaki, H.; Ozawa, K.; Inuzuka, M.; Sakaguchi, T.; Isobe, T.; Gunji, T.; Morino, Y.; Saito, S.; Yamaguchi, Y.L.; Sawada, S.; Yokkaichi, S.

    2006-01-01

    We developed a prototype time projection chamber using gas electron multipliers (GEM-TPC) for high energy heavy ion collision experiments. To investigate its performance, we conducted a beam test with three kinds of gases (Ar(90%)-CH 4 (10%), Ar(70%)-C 2 H 6 (30%) and CF 4 ). Detection efficiency of 99%, and spatial resolution of 79μm in the pad-row direction and 313μm in the drift direction were achieved. The test results show that the GEM-TPC meets the requirements for high energy heavy ion collision experiments. The configuration and performance of the GEM-TPC are described

  8. Time evolution analysis of the electron distribution in Thomson/Compton back-scattering

    International Nuclear Information System (INIS)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Maroli, C.; Serafini, L.; Rossi, A. R.

    2013-01-01

    We present the time evolution of the energy distribution of a relativistic electron beam after the Compton back-scattering with a counter-propagating laser field, performed in the framework of the Quantum Electrodynamics, by means of the code CAIN. As the correct angular distribution of the spontaneous emission is accounted, the main effect is the formation of few stripes, followed by the diffusion of the more energetic particles toward lower values in the longitudinal phase space. The Chapman-Kolmogorov master equation gives results in striking agreement with the numerical ones. An experiment on the Thomson source at SPARC-LAB is proposed

  9. Measurement of electron paramagnetic resonance using terahertz time-domain spectroscopy.

    Science.gov (United States)

    Kozuki, Kohei; Nagashima, Takeshi; Hangyo, Masanori

    2011-12-05

    We present a frequency-domain electron spin resonance (ESR) measurement system using terahertz time-domain spectroscopy. A crossed polarizer technique is utilized to increase the sensitivity in detecting weak ESR signals of paramagnets caused by magnetic dipole transitions between magnetic sublevels. We demonstrate the measurements of ESR signal of paramagnetic copper(II) sulfate pentahydrate with uniaxial anisotropy of the g-factor under magnetic fields up to 10 T. The lineshape of the obtained ESR signals agrees well with the theoretical predictions for a powder sample with the uniaxial anisotropy.

  10. Wireless, intraoral hybrid electronics for real-time quantification of sodium intake toward hypertension management.

    Science.gov (United States)

    Lee, Yongkuk; Howe, Connor; Mishra, Saswat; Lee, Dong Sup; Mahmood, Musa; Piper, Matthew; Kim, Youngbin; Tieu, Katie; Byun, Hun-Soo; Coffey, James P; Shayan, Mahdis; Chun, Youngjae; Costanzo, Richard M; Yeo, Woon-Hong

    2018-05-22

    Recent wearable devices offer portable monitoring of biopotentials, heart rate, or physical activity, allowing for active management of human health and wellness. Such systems can be inserted in the oral cavity for measuring food intake in regard to controlling eating behavior, directly related to diseases such as hypertension, diabetes, and obesity. However, existing devices using plastic circuit boards and rigid sensors are not ideal for oral insertion. A user-comfortable system for the oral cavity requires an ultrathin, low-profile, and soft electronic platform along with miniaturized sensors. Here, we introduce a stretchable hybrid electronic system that has an exceptionally small form factor, enabling a long-range wireless monitoring of sodium intake. Computational study of flexible mechanics and soft materials provides fundamental aspects of key design factors for a tissue-friendly configuration, incorporating a stretchable circuit and sensor. Analytical calculation and experimental study enables reliable wireless circuitry that accommodates dynamic mechanical stress. Systematic in vitro modeling characterizes the functionality of a sodium sensor in the electronics. In vivo demonstration with human subjects captures the device feasibility for real-time quantification of sodium intake, which can be used to manage hypertension.

  11. Introduction of electronic referral from community associated with more timely review by secondary services.

    Science.gov (United States)

    Warren, J; White, S; Day, K J; Gu, Y; Pollock, M

    2011-01-01

    Electronic referral (eReferral) from community into public secondary healthcare services was introduced to 30 referring general medical practices and 28 hospital based services in late 2007. To measure the extent of uptake of eReferral and its association with changes in referral processing. Analysis of transactional data from the eReferral message service and the patient information management system of the affected hospital; interview of clinical, operational and management stakeholders. eReferral use rose steadily to 1000 transactions per month in 2008, thereafter showing moderate growth to 1200 per month in 2010. Rate of eReferral from the community in 2010 is estimated at 56% of total referrals to the hospital from general practice, and as 71% of referrals from those having done at least one referral electronically. Referral latency from letter date to hospital triage improves significantly from 2007 to 2009 (psystem usability issues. With eReferrals, a referral's status can be checked, and its content read, by any authorized user at any time. The period of eReferral uptake was associated with significant speed-up in referral processing without changes in staffing levels. The eReferral system provides a foundation for further innovation in the community-secondary interface, such as electronic decision support and shared care planning systems. We observed substantial rapid voluntary uptake of eReferrals associated with faster, more reliable and more transparent referral processing.

  12. Reflective optical system for time-resolved electron bunch measurements at PITZ

    Energy Technology Data Exchange (ETDEWEB)

    Rosbach, K; Baehr, J [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Roensch-Schulenburg, J [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik

    2011-01-15

    The Photo-Injector Test facility at DESY, Zeuthen site (PITZ), produces pulsed electron beams with low transverse emittance and is equipped with diagnostic devices for measuring various electron bunch properties, including the longitudinal and transverse electron phase space distributions. The longitudinal bunch structure is recorded using a streak camera located outside the accelerator tunnel, connected to the diagnostics in the beam-line stations by an optical system of about 30 m length. This system mainly consists of telescopes of achromatic lenses, which transport the light pulses and image them onto the entrance slit of the streak camera. Due to dispersion in the lenses, the temporal resolution degrades during transport. This article presents general considerations for time-resolving optical systems as well as simulations and measurements of specific candidate systems. It then describes the development of an imaging system based on mirror telescopes which will improve the temporal resolution, with an emphasis on off-axis parabolic mirror systems working at unit magnification. A hybrid system of lenses and mirrors will serve as a proof of principle. (orig.)

  13. The Sidereal Time Variations of the Lorentz Force and Maximum Attainable Speed of Electrons

    Science.gov (United States)

    Nowak, Gabriel; Wojtsekhowski, Bogdan; Roblin, Yves; Schmookler, Barak

    2016-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab produces electrons that orbit through a known magnetic system. The electron beam's momentum can be determined through the radius of the beam's orbit. This project compares the beam orbit's radius while travelling in a transverse magnetic field with theoretical predictions from special relativity, which predict a constant beam orbit radius. Variations in the beam orbit's radius are found by comparing the beam's momentum entering and exiting a magnetic arc. Beam position monitors (BPMs) provide the information needed to calculate the beam momentum. Multiple BPM's are included in the analysis and fitted using the method of least squares to decrease statistical uncertainty. Preliminary results from data collected over a 24 hour period show that the relative momentum change was less than 10-4. Further study will be conducted including larger time spans and stricter cuts applied to the BPM data. The data from this analysis will be used in a larger experiment attempting to verify special relativity. While the project is not traditionally nuclear physics, it involves the same technology (the CEBAF accelerator) and the same methods (ROOT) as a nuclear physics experiment. DOE SULI Program.

  14. Optimal testing input sets for reduced diagnosis time of nuclear power plant digital electronic circuits

    International Nuclear Information System (INIS)

    Kim, D.S.; Seong, P.H.

    1994-01-01

    This paper describes the optimal testing input sets required for the fault diagnosis of the nuclear power plant digital electronic circuits. With the complicated systems such as very large scale integration (VLSI), nuclear power plant (NPP), and aircraft, testing is the major factor of the maintenance of the system. Particularly, diagnosis time grows quickly with the complexity of the component. In this research, for reduce diagnosis time the authors derived the optimal testing sets that are the minimal testing sets required for detecting the failure and for locating of the failed component. For reduced diagnosis time, the technique presented by Hayes fits best for the approach to testing sets generation among many conventional methods. However, this method has the following disadvantages: (a) it considers only the simple network (b) it concerns only whether the system is in failed state or not and does not provide the way to locate the failed component. Therefore the authors have derived the optimal testing input sets that resolve these problems by Hayes while preserving its advantages. When they applied the optimal testing sets to the automatic fault diagnosis system (AFDS) which incorporates the advanced fault diagnosis method of artificial intelligence technique, they found that the fault diagnosis using the optimal testing sets makes testing the digital electronic circuits much faster than that using exhaustive testing input sets; when they applied them to test the Universal (UV) Card which is a nuclear power plant digital input/output solid state protection system card, they reduced the testing time up to about 100 times

  15. PREFACE: IV Nanotechnology International Forum (RUSNANOTECH 2011)

    Science.gov (United States)

    Dvurechenskii, Anatoly; Alfimov, Mikhail; Suzdalev, Igor; Osiko, Vyacheslav; Khokhlov, Aleksey; Son, Eduard; Skryabin, Konstantin; Petrov, Rem; Deev, Sergey

    2012-02-01

    Logo The RUSNANOTECH 2011 International Forum on Nanotechnology was held from 26-28 October 2011, in Moscow, Russia. It was the fourth forum organized by RUSNANO (Russian Corporation of Nanotechnologies) since 2008. In March 2011 RUSNANO was established as an open joint-stock company through the reorganization of the state corporation Russian Corporation of Nanotechnologies. RUSNANO's mission is to develop the Russian nanotechnology industry through co-investment in nanotechnology projects with substantial economic potential or social benefit. Within the framework of the Forum Science and Technology Program, presentations on key trends of nanotechnology development were given by foreign and Russian scientists, R&D officers of leading international companies, universities and scientific centers. The science and technology program of the Forum was divided into four sections as follows (by following hyperlinks you may find each section's program including videos of all oral presentations): Nanoelectronics and Nanophotonics Nanomaterials Nanotechnology and Green Energy Nanotechnology in Healthcare and Pharma (United business and science & technology section on 'RUSNANOTECH 2011') The scientific program of the forum included more than 50 oral presentations by leading scientists from 15 countries. Among them were world-known specialists such as Professor S Bader (Argonne National Laboratory, USA), Professor O Farokzhad (Harvard Medical School, USA), Professor K Chien (Massachusetts General Hospital, USA), Professor L Liz-Marzan (University of Vigo), A Luque (Polytechnic University of Madrid) and many others. The poster session consisted of over 120 presentations, 90 of which were presented in the framework of the young scientists' nanotechnology papers competition. This volume of Journal of Physics: Conference Series includes a selection of 47 submissions. Section editors of the proceedings: Nanoelectronics and nanophotonics Corresponding Member of Russian Academy of

  16. Angle-resolving time-of-flight electron spectrometer for near-threshold precision measurements of differential cross sections of electron-impact excitation of atoms and molecules

    International Nuclear Information System (INIS)

    Lange, M.; Matsumoto, J.; Setiawan, A.; Panajotovic, R.; Harrison, J.; Lower, J. C. A.; Newman, D. S.; Mondal, S.; Buckman, S. J.

    2008-01-01

    This article presents a new type of low-energy crossed-beam electron spectrometer for measuring angular differential cross sections of electron-impact excitation of atomic and molecular targets. Designed for investigations at energies close to excitation thresholds, the spectrometer combines a pulsed electron beam with the time-of-flight technique to distinguish between scattering channels. A large-area, position-sensitive detector is used to offset the low average scattering rate resulting from the pulsing duty cycle, without sacrificing angular resolution. A total energy resolution better than 150 meV (full width at half maximum) at scattered energies of 0.5-3 eV is achieved by monochromating the electron beam prior to pulsing it. The results of a precision measurement of the differential cross section for electron-impact excitation of helium, at an energy of 22 eV, are used to assess the sensitivity and resolution of the spectrometer

  17. Declaration of the National Forum on Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-03

    The purpose of the National Forum on Climate Change was to raise public awareness of the climate change issue and to bring citizens` viewpoint to the debate. The Forum was a unique conference in that the principal attendees, while lay persons as far as climate change is concerned, were members of the Order of Canada. The Order of Canada is an honour bestowed upon upon a relatively small number of Canadian citizens from all walks of life who have made significant contributions to the betterment of their professions or communities or distinguished themselves nationally or internationally. It was the first time that recipients of this high honour were called upon collectively to address an issue of national policy. This declaration was issued at the conclusion of the round table discussions. It expresses their conclusions about climate change, what it is, what are its potential impacts, the scientific uncertainties surrounding the issue, and the actions that can and must be taken by governments and individual citizens to deal with the problem.

  18. Forum: The Lecture and Student Learning. What Is the Place of Lecture in Student Learning Today?

    Science.gov (United States)

    Stearns, Susan

    2017-01-01

    The author of this brief forum article argues that it is time to encourage faculty members to rethink student learning: encourage the scholarship of teaching and expose faculty to key research articles about student learning. Then, building on this knowledge, the academy needs to offer assistance to faculty in designing student-centered…

  19. 78 FR 14840 - U.S.-EU High Level Regulatory Cooperation Forum-Stakeholder Session

    Science.gov (United States)

    2013-03-07

    ... OFFICE OF MANAGEMENT AND BUDGET U.S.-EU High Level Regulatory Cooperation Forum--Stakeholder... the future. Time constraints may prevent some stakeholders from making presentations on April 10th or... stakeholder session agenda will in no way prejudge the specific elements of a future transatlantic regulatory...

  20. Real-time measurement of electron beam weld penetration in uranium by acoustic emission monitoring

    International Nuclear Information System (INIS)

    Whittaker, J.W.; Murphy, J.L.

    1991-07-01

    High quality electron beam (EB) welds are required in uranium test articles. Acoustic emission (AE) techniques are under development with the goal of measuring weld penetration in real-time. One technique, based on Average Signal Level (ASL) measurement was used to record weld AE signatures. Characteristic AE signatures were recorded for bead-on-plate (BOP) and butt joint (BJ) welds made under varied welding conditions. AE waveforms were sampled to determine what microscopic AE behavior led to the observed macroscopic signature features. Deformation twinning and weld expulsion are two of the main sources of emission. AE behavior was correlated with weld penetration as measured by standard metallographic techniques. The ASL value was found to increase approximately linearly with weld penetration in BJ welds. These results form the basis for a real-time monitoring technique for weld penetration. 5 refs

  1. Global Model of Time-Modulated Electronegative Discharges for Neutral Radical and Electron Temperature Control

    Science.gov (United States)

    Kim, Sungjin; Lieberman, M. A.; Lichtenberg, A. J.

    2003-10-01

    Control and reduction of neutral radical flux/ion flux ratio and electron temperature Te is required for next generation etching in the microelectronics industry. We investigate time-modulated power for these purposes using a volume-averaged (global) oxygen discharge model, We consider pressures of 10-50 mTorr and plasma densities of 10^10-10^11 cm-3. In this regime, the discharge is found to be weakly electronegative. The modulation period and the duty ratio (on-time/period) are varied to determine the optimum conditions for reduction of FR= O-atom flux/ion flux and T_e. Two chambers with different height/diameter ratios (SMART Contract SM99-10051.

  2. Imaginary time density-density correlations for two-dimensional electron gases at high density

    Energy Technology Data Exchange (ETDEWEB)

    Motta, M.; Galli, D. E. [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Moroni, S. [IOM-CNR DEMOCRITOS National Simulation Center and SISSA, Via Bonomea 265, 34136 Trieste (Italy); Vitali, E. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)

    2015-10-28

    We evaluate imaginary time density-density correlation functions for two-dimensional homogeneous electron gases of up to 42 particles in the continuum using the phaseless auxiliary field quantum Monte Carlo method. We use periodic boundary conditions and up to 300 plane waves as basis set elements. We show that such methodology, once equipped with suitable numerical stabilization techniques necessary to deal with exponentials, products, and inversions of large matrices, gives access to the calculation of imaginary time correlation functions for medium-sized systems. We discuss the numerical stabilization techniques and the computational complexity of the methodology and we present the limitations related to the size of the systems on a quantitative basis. We perform the inverse Laplace transform of the obtained density-density correlation functions, assessing the ability of the phaseless auxiliary field quantum Monte Carlo method to evaluate dynamical properties of medium-sized homogeneous fermion systems.

  3. Monitoring storage time and quality attribute of egg based on electronic nose

    International Nuclear Information System (INIS)

    Wang Yongwei; Jun Wang; Bo Zhou; Qiujun Lu

    2009-01-01

    The objective of this study was to investigate the potential of an electronic nose (E-nose) technique for monitoring egg storage time and quality attributes. An electronic nose was used to distinguish eggs under cool and room-temperature storage by means of principal component analysis (PCA), linear discriminant analysis (LDA), BP neural network (BPNN) and the combination of a genetic algorithm and BP neural network (GANN). Results showed that the E-nose could distinguish eggs of different storage time under cool and room-temperature storage by LDA, PCA, BPNN and GANN; better prediction values were obtained by GANN than by BPNN. Relationships were established between the E-nose signal and egg quality indices (Haugh unit and yolk factor) by quadratic polynomial step regression (QPSR). The prediction models for Haugh unit and yolk factor indicated a good prediction performance. The Haugh unit model had a standard error of prediction of 3.74 and correlation coefficient 0.91; the yolk factor model had a 0.02 SEP and 0.93 correlation coefficient between predicted and measured values respectively.

  4. Excited-state structure and electronic dephasing time of Nile blue from absolute resonance Raman intensities

    Science.gov (United States)

    Lawless, Mary K.; Mathies, Richard A.

    1992-06-01

    Absolute resonance Raman cross sections are measured for Nile blue 690 perchlorate dissolved in ethylene glycol with excitation at 514, 531, and 568 nm. These values and the absorption spectrum are modeled using a time-dependent wave packet formalism. The excited-state equilibrium geometry changes are quantitated for 40 resonance Raman active modes, seven of which (590, 1141, 1351, 1429, 1492, 1544, and 1640 cm-1 ) carry 70% of the total resonance Raman intensity. This demonstrates that in addition to the prominent 590 and 1640 cm-1 modes, a large number of vibrational degrees of freedom are Franck-Condon coupled to the electronic transition. After exposure of the explicit vibrational progressions, the residual absorption linewidth is separated into its homogeneous [350 cm-1 half-width at half-maximum (HWHM)] and inhomogeneous (313 cm-1 HWHM) components through an analysis of the absolute Raman cross sections. The value of the electronic dephasing time derived from this study (25 fs) compares well to previously published results. These data should be valuable in multimode modeling of femtosecond experiments on Nile blue.

  5. Optical Response of Warm Dense Matter Using Real-Time Electron Dynamics

    Science.gov (United States)

    Baczewski, Andrew; Shulenburger, Luke; Desjarlais, Michael; Magyar, Rudolph

    2014-03-01

    The extreme temperatures and solid-like densities in warm dense matter present a unique challenge for theory, wherein neither conventional models from condensed matter nor plasma physics capture all of the relevant phenomenology. While Kubo-Greenwood DFT calculations have proven capable of reproducing optical properties of WDM, they require a significant number of virtual orbitals to reach convergence due to their perturbative nature. Real-time TDDFT presents a complementary framework with a number of computationally favorable properties, including reduced cost complexity and better scalability, and has been used to reproduce the optical response of finite and ordered extended systems. We will describe the use of Ehrenfest-TDDFT to evolve coupled electron-nuclear dynamics in WDM systems, and the subsequent evaluation of optical response functions from the real-time electron dynamics. The advantages and disadvantages of this approach will be discussed relative to the current state-of-the-art. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Security Administration under contract DE-AC04-94AL85000.

  6. Procedure prediction from symbolic Electronic Health Records via time intervals analytics.

    Science.gov (United States)

    Moskovitch, Robert; Polubriaginof, Fernanda; Weiss, Aviram; Ryan, Patrick; Tatonetti, Nicholas

    2017-11-01

    Prediction of medical events, such as clinical procedures, is essential for preventing disease, understanding disease mechanism, and increasing patient quality of care. Although longitudinal clinical data from Electronic Health Records provides opportunities to develop predictive models, the use of these data faces significant challenges. Primarily, while the data are longitudinal and represent thousands of conceptual events having duration, they are also sparse, complicating the application of traditional analysis approaches. Furthermore, the framework presented here takes advantage of the events duration and gaps. International standards for electronic healthcare data represent data elements, such as procedures, conditions, and drug exposures, using eras, or time intervals. Such eras contain both an event and a duration and enable the application of time intervals mining - a relatively new subfield of data mining. In this study, we present Maitreya, a framework for time intervals analytics in longitudinal clinical data. Maitreya discovers frequent time intervals related patterns (TIRPs), which we use as prognostic markers for modelling clinical events. We introduce three novel TIRP metrics that are normalized versions of the horizontal-support, that represents the number of TIRP instances per patient. We evaluate Maitreya on 28 frequent and clinically important procedures, using the three novel TIRP representation metrics in comparison to no temporal representation and previous TIRPs metrics. We also evaluate the epsilon value that makes Allen's relations more flexible with several settings of 30, 60, 90 and 180days in comparison to the default zero. For twenty-two of these procedures, the use of temporal patterns as predictors was superior to non-temporal features, and the use of the vertically normalized horizontal support metric to represent TIRPs as features was most effective. The use of the epsilon value with thirty days was slightly better than the zero

  7. Universal behaviour in the stock market: Time dynamics of the electronic orderbook

    Energy Technology Data Exchange (ETDEWEB)

    Kızılersü, Ayşe, E-mail: ayse.kizilersu@adelaide.edu.au [Special Research Centre for the Subatomic Structure of Matter (CSSM), Department of Physics, School of Chemistry and Physics, Adelaide University, 5005 (Australia); Kreer, Markus [phi-t products & services, Karlsruher Strasse 88, 76139 Karlsruhe (Germany); Thomas, Anthony W. [CoEPP and CSSM, Department of Physics, Adelaide University, SA 5005 (Australia); Feindt, Michael [Blue Yonder GmbH, Ohiostraße 8, 756139 Karlsruhe (Germany)

    2016-07-29

    A consequence of the digital revolution is that share trading at the stock exchange takes place via electronic order books which are accessed by traders and investors via the internet. Our empirical findings of the London Stock Exchange demonstrate that once ultra-high frequency manipulation on time scales less than around ten milliseconds is excluded, all relevant changes in the order book happen with time differences that are randomly distributed and well described by a left-truncated Weibull distribution with universal shape parameter (independent of time and same for all stocks). The universal shape parameter corresponds to maximum entropy of the distribution. - Highlights: • After the ultra-high frequency manipulation is excluded, all the time differences in the EOB described by a left-truncated Weibull distribution. • The Weibull shape parameter is universal i.e. independent of time and same for all stocks and it is equal to Euler–Mascheroni constant. • The universal shape parameter corresponds to maximum entropy of the distribution.

  8. Time-Dependent Variations in Structure of Sheep Wool Irradiated by Electron Beam

    Directory of Open Access Journals (Sweden)

    Zuzana Hanzlíková

    2017-01-01

    Full Text Available Wool scoured in tap water with no special degreasing and containing a balanced humidity responding to usual laboratory conditions was irradiated by accelerated electron beam in the range of 0–350 kGy dose. Time variations of the wool structure were measured using FTIR, Raman, and EPR spectroscopy. The aim was to determine whether preexposure treatment of the wool, as well as postexposure time, affects the properties of the irradiated wool. Reactive products such as S-sulfonate, cystine monoxide, cystine dioxide, cysteic acid, disulphides, and carboxylates displayed a considerable fluctuation in quantity depending on both the absorbed dose and time. Mutual transformations of S-oxidized products into cysteic acid appeared to be faster than those in dry and degreased wool assuming that the present humidity inside the fibres is decisive as an oxygen source. EPR results indicated a longer lifetime for free radicals induced by lower doses compared with the radicals generated by higher ones. The pattern of the conformational composition of the secondary structure (α-helix, β-sheet, random, and residual conformations also showed a large variability depending on absorbed dose as well as postexposure time. The most stable secondary structure was observed in nonirradiated wool but even this showed a small but observable change after a longer time, too.

  9. TIME MANAGEMENT SKILLS IN HIGHER INSTITUTIONS: A CASE STUDY OF ELECTRICAL, ELECTRONIC & SYSTEMS ENGINEERING UNDERGRADUATE STUDENTS

    Directory of Open Access Journals (Sweden)

    NORBAHIAH MISRAN

    2016-11-01

    Full Text Available Time management is an important skill that every student in higher education institutions should acquire since it is one of the key factors in assuring excellent achievement in academic. Students with poor time-management skills are far more likely to be tressed and, as a result, have a negative impact on the quality of life. Thus, this paper discusses this issue based on a study among students of Electrical, Electronic & System Engineering at Universiti Kebangsaan Malaysia according to year of study and then establishes the relationship with the student's academic performance. Data were collected using a set of questionnaire carried out on 272 undergraduate students from year one to year four for 2015/2016 session. These data were then analysed using ANOVA statistical inference and Pearson correlations. Results revealed that time management skills of the respondents were at moderate level and established a negative correlation with year of study. This study also found significant findings where time management skills have a positive but weak correlation with student’s academic performance. These findings suggest the need for additional research to further refine the justifications of these measures. The university is also anticipated to provide a good platform for students to develop their time management skills at the early stage of their admission to university.

  10. Universal behaviour in the stock market: Time dynamics of the electronic orderbook

    International Nuclear Information System (INIS)

    Kızılersü, Ayşe; Kreer, Markus; Thomas, Anthony W.; Feindt, Michael

    2016-01-01

    A consequence of the digital revolution is that share trading at the stock exchange takes place via electronic order books which are accessed by traders and investors via the internet. Our empirical findings of the London Stock Exchange demonstrate that once ultra-high frequency manipulation on time scales less than around ten milliseconds is excluded, all relevant changes in the order book happen with time differences that are randomly distributed and well described by a left-truncated Weibull distribution with universal shape parameter (independent of time and same for all stocks). The universal shape parameter corresponds to maximum entropy of the distribution. - Highlights: • After the ultra-high frequency manipulation is excluded, all the time differences in the EOB described by a left-truncated Weibull distribution. • The Weibull shape parameter is universal i.e. independent of time and same for all stocks and it is equal to Euler–Mascheroni constant. • The universal shape parameter corresponds to maximum entropy of the distribution.

  11. Forum on stakeholder confidence: Spain

    International Nuclear Information System (INIS)

    Vari, A.; Pescatore, C.

    2006-01-01

    The FSC workshop in Spain provided an important opportunity to carry out an in-depth examination of decision-making processes undertaken in an NEA member country, and to reflect on the evolution that has taken place over time. It offered a well-rounded perspective on the inclusion of stakeholders in decision making, and the atmosphere of the meetings was conducive to an honest and open exchange of ideas. The workshop started with the introduction of two case studies: the earlier attempt in Spain to locate a potential site for a high-level waste (HLW) disposal facility, and the dismantling of the Vandellos-I nuclear power plant. This was followed by two days of presentations and round-table discussions based on the recent COWAM Spain initiative (stemming from the EU-wide project on Community Waste Management), which aims at developing recommendations for institutional arrangements and decision-making processes concerning the siting of waste management facilities in Spain. This article provides a brief summary of the case studies and the COWAM Spain initiative, followed by some of the lessons learnt from an international perspective. (authors)

  12. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  13. Non parametric denoising methods based on wavelets: Application to electron microscopy images in low exposure time

    International Nuclear Information System (INIS)

    Soumia, Sid Ahmed; Messali, Zoubeida; Ouahabi, Abdeldjalil; Trepout, Sylvain; Messaoudi, Cedric; Marco, Sergio

    2015-01-01

    The 3D reconstruction of the Cryo-Transmission Electron Microscopy (Cryo-TEM) and Energy Filtering TEM images (EFTEM) hampered by the noisy nature of these images, so that their alignment becomes so difficult. This noise refers to the collision between the frozen hydrated biological samples and the electrons beam, where the specimen is exposed to the radiation with a high exposure time. This sensitivity to the electrons beam led specialists to obtain the specimen projection images at very low exposure time, which resulting the emergence of a new problem, an extremely low signal-to-noise ratio (SNR). This paper investigates the problem of TEM images denoising when they are acquired at very low exposure time. So, our main objective is to enhance the quality of TEM images to improve the alignment process which will in turn improve the three dimensional tomography reconstructions. We have done multiple tests on special TEM images acquired at different exposure time 0.5s, 0.2s, 0.1s and 1s (i.e. with different values of SNR)) and equipped by Golding beads for helping us in the assessment step. We herein, propose a structure to combine multiple noisy copies of the TEM images. The structure is based on four different denoising methods, to combine the multiple noisy TEM images copies. Namely, the four different methods are Soft, the Hard as Wavelet-Thresholding methods, Bilateral Filter as a non-linear technique able to maintain the edges neatly, and the Bayesian approach in the wavelet domain, in which context modeling is used to estimate the parameter for each coefficient. To ensure getting a high signal-to-noise ratio, we have guaranteed that we are using the appropriate wavelet family at the appropriate level. So we have chosen âĂIJsym8âĂİ wavelet at level 3 as the most appropriate parameter. Whereas, for the bilateral filtering many tests are done in order to determine the proper filter parameters represented by the size of the filter, the range parameter and the

  14. Time delay and duration of ionospheric total electron content responses to geomagnetic disturbances

    Directory of Open Access Journals (Sweden)

    J. Liu

    2010-03-01

    Full Text Available Although positive and negative signatures of ionospheric storms have been reported many times, global characteristics such as the time of occurrence, time delay and duration as well as their relations to the intensity of the ionospheric storms have not received enough attention. The 10 years of global ionosphere maps (GIMs of total electron content (TEC retrieved at Jet Propulsion Laboratory (JPL were used to conduct a statistical study of the time delay of the ionospheric responses to geomagnetic disturbances. Our results show that the time delays between geomagnetic disturbances and TEC responses depend on season, magnetic local time and magnetic latitude. In the summer hemisphere at mid- and high latitudes, the negative storm effects can propagate to the low latitudes at post-midnight to the morning sector with a time delay of 4–7 h. As the earth rotates to the sunlight, negative phase retreats to higher latitudes and starts to extend to the lower latitude toward midnight sector. In the winter hemisphere during the daytime and after sunset at mid- and low latitudes, the negative phase appearance time is delayed from 1–10 h depending on the local time, latitude and storm intensity compared to the same area in the summer hemisphere. The quick response of positive phase can be observed at the auroral area in the night-side of the winter hemisphere. At the low latitudes during the dawn-noon sector, the ionospheric negative phase responses quickly with time delays of 5–7 h in both equinoctial and solsticial months.

    Our results also manifest that there is a positive correlation between the intensity of geomagnetic disturbances and the time duration of both the positive phase and negative phase. The durations of both negative phase and positive phase have clear latitudinal, seasonal and magnetic local time (MLT dependence. In the winter hemisphere, long durations for the positive phase are 8–11 h and 12–14 h during the daytime at

  15. Time delay and duration of ionospheric total electron content responses to geomagnetic disturbances

    Directory of Open Access Journals (Sweden)

    J. Liu

    2010-03-01

    Full Text Available Although positive and negative signatures of ionospheric storms have been reported many times, global characteristics such as the time of occurrence, time delay and duration as well as their relations to the intensity of the ionospheric storms have not received enough attention. The 10 years of global ionosphere maps (GIMs of total electron content (TEC retrieved at Jet Propulsion Laboratory (JPL were used to conduct a statistical study of the time delay of the ionospheric responses to geomagnetic disturbances. Our results show that the time delays between geomagnetic disturbances and TEC responses depend on season, magnetic local time and magnetic latitude. In the summer hemisphere at mid- and high latitudes, the negative storm effects can propagate to the low latitudes at post-midnight to the morning sector with a time delay of 4–7 h. As the earth rotates to the sunlight, negative phase retreats to higher latitudes and starts to extend to the lower latitude toward midnight sector. In the winter hemisphere during the daytime and after sunset at mid- and low latitudes, the negative phase appearance time is delayed from 1–10 h depending on the local time, latitude and storm intensity compared to the same area in the summer hemisphere. The quick response of positive phase can be observed at the auroral area in the night-side of the winter hemisphere. At the low latitudes during the dawn-noon sector, the ionospheric negative phase responses quickly with time delays of 5–7 h in both equinoctial and solsticial months. Our results also manifest that there is a positive correlation between the intensity of geomagnetic disturbances and the time duration of both the positive phase and negative phase. The durations of both negative phase and positive phase have clear latitudinal, seasonal and magnetic local time (MLT dependence. In the winter hemisphere, long durations for the positive phase are 8–11 h and 12–14 h during the daytime at middle

  16. Electron-spin dynamics in Mn-doped GaAs using time-resolved magneto-optical techniques

    Science.gov (United States)

    Akimov, I. A.; Dzhioev, R. I.; Korenev, V. L.; Kusrayev, Yu. G.; Zhukov, E. A.; Yakovlev, D. R.; Bayer, M.

    2009-08-01

    We study the electron-spin dynamics in p -type GaAs doped with magnetic Mn acceptors by means of time-resolved pump-probe and photoluminescence techniques. Measurements in transverse magnetic fields show a long spin-relaxation time of 20 ns that can be uniquely related to electrons. Application of weak longitudinal magnetic fields above 100 mT extends the spin-relaxation times up to microseconds which is explained by suppression of the Bir-Aronov-Pikus spin relaxation for the electron on the Mn acceptor.

  17. Reflection-time-of-flight spectrometer for two-electron (e,2e) coincidence spectroscopy on surfaces

    International Nuclear Information System (INIS)

    Kirschner, J.; Kerherve, G.; Winkler, C.

    2008-01-01

    In this article, a novel time-of-flight spectrometer for two-electron-emission (e,2e/γ,2e) correlation spectroscopy from surfaces at low electron energies is presented. The spectrometer consists of electron optics that collect emitted electrons over a solid angle of approximately 1 sr and focus them onto a multichannel plate using a reflection technique. The flight time of an electron with kinetic energy of E kin ≅25 eV is around 100 ns. The corresponding time- and energy resolution are typically ≅1 ns and ≅0.65 eV, respectively. The first (e,2e) data obtained with the present setup from a LiF film are presented

  18. Electronic health record innovations: Helping physicians - One less click at a time.

    Science.gov (United States)

    Guo, Uta; Chen, Lu; Mehta, Parag H

    2017-09-01

    Physician burnout is becoming an epidemic, due to the pressures of being productive, an imperfect electronic health record (EHR) system, and limited face-to-face time with patients. Poor usability in EHR-user interface can force users to go through more steps (i.e. more clicks on the computer) in accomplishing a task. This increased 'click burden' is a source of frustration for physicians. In the light of increased click burden and time due to meaningful use requirements, there is a need to improve the physician's experience by creating innovations in EHR. This case study describes an attempt by physicians at NewYork-Presbyterian Brooklyn Methodist Hospital to enhance the EHR experience with more efficient methods of documentation, chart review, ordering and patient safety. The EHR innovations trialled in this study were: a mobile documentation application; abnormal test results auto-populated into an EHR patient summary; physician alerts to reduce inappropriate test ordering; and a system of safety alerts on a dashboard. These innovations led to decreased click burden and allowed physicians to spend less time on the computer and more time with patients. Physician-driven changes to EHR systems have the potential to streamline virtual workflows and the management of health information and to improve patient safety, reduce physician burnout and increase physician job satisfaction.

  19. Optimized quantum sensing with a single electron spin using real-time adaptive measurements

    Science.gov (United States)

    Bonato, C.; Blok, M. S.; Dinani, H. T.; Berry, D. W.; Markham, M. L.; Twitchen, D. J.; Hanson, R.

    2016-03-01

    Quantum sensors based on single solid-state spins promise a unique combination of sensitivity and spatial resolution. The key challenge in sensing is to achieve minimum estimation uncertainty within a given time and with high dynamic range. Adaptive strategies have been proposed to achieve optimal performance, but their implementation in solid-state systems has been hindered by the demanding experimental requirements. Here, we realize adaptive d.c. sensing by combining single-shot readout of an electron spin in diamond with fast feedback. By adapting the spin readout basis in real time based on previous outcomes, we demonstrate a sensitivity in Ramsey interferometry surpassing the standard measurement limit. Furthermore, we find by simulations and experiments that adaptive protocols offer a distinctive advantage over the best known non-adaptive protocols when overhead and limited estimation time are taken into account. Using an optimized adaptive protocol we achieve a magnetic field sensitivity of 6.1 ± 1.7 nT Hz-1/2 over a wide range of 1.78 mT. These results open up a new class of experiments for solid-state sensors in which real-time knowledge of the measurement history is exploited to obtain optimal performance.

  20. A Hybrid Approach for Thread Recommendation in MOOC Forums

    OpenAIRE

    Ahmad. A. Kardan; Amir Narimani; Foozhan Ataiefard

    2017-01-01

    Recommender Systems have been developed to provide contents and services compatible to users based on their behaviors and interests. Due to information overload in online discussion forums and users diverse interests, recommending relative topics and threads is considered to be helpful for improving the ease of forum usage. In order to lead learners to find relevant information in educational forums, recommendations are even more needed. We present a hybrid thread recommender system for MOOC ...

  1. High energy resolution and first time-dependent positron annihilation induced Auger electron spectroscopty

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Jakob

    2010-04-03

    It was the aim of this thesis to improve the existing positron annihilation induced Auger spectrometer at the highly intense positron source NEPOMUC (NEutron induced POsitron source MUniCh) in several ways: Firstly, the measurement time for a single spectrum should be reduced from typically 12 h to roughly 1 h or even less. Secondly, the energy resolution, which amounted to {delta}E/E{approx}10%, should be increased by at least one order of magnitude in order to make high resolution positron annihilation induced Auger spectroscopy (PAES)-measurements of Auger transitions possible and thus deliver more information about the nature of the Auger process. In order to achieve these objectives, the PAES spectrometer was equipped with a new electron energy analyzer. For its ideal operation all other components of the Auger analysis chamber had to be adapted. Particularly the sample manipulation and the positron beam guidance had to be renewed. Simulations with SIMION {sup registered} ensured the optimal positron lens parameters. After the adjustment of the new analyzer and its components, first measurements illustrated the improved performance of the PAES setup: Firstly, the measurement time for short overview measurements was reduced from 3 h to 420 s. The measurement time for more detailed Auger spectra was shortened from 12 h to 80 min. Secondly, even with the reduced measurement time, the signal to noise ratio was also enhanced by one order of magnitude. Finally, the energy resolution was improved to {delta}E/E < 1. The exceptional surface sensitivity and elemental selectivity of PAES was demonstrated in measurements of Pd and Fe, both coated with Cu layers of varying thickness. PAES showed that with 0.96 monolayer of Cu on Fe, more than 55% of the detected Auger electrons stem from Cu. In the case of the Cu coated Pd sample 0.96 monolayer of Cu resulted in a Cu Auger fraction of more than 30% with PAES and less than 5% with electron induced Auger spectroscopy

  2. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    International Nuclear Information System (INIS)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjaergaard, Christina; Jain, Mayank; Lapp, Torben

    2010-01-01

    A time-resolved optically stimulated exo-electron (TR-OSE) measurement system has been developed using a Photon Timer attached to a gas-flow semi-proportional pancake electron detector within a Risoe TL/OSL reader. The decay rate of the exo-electron emission after the stimulation pulse depends on the probability of (1) escape of electrons into the detector gas from the conduction band by overcoming the work function of the material and (2) thermalization of electrons in the conduction band, and subsequent re-trapping/recombination. Thus, we expect the exo-electron signal to reflect the instantaneous electron concentration in the conduction band. In this study, TR-OSE and time-resolved optically stimulated luminescence (TR-OSL) were measured for the first time using quartz, K-feldspar and NaCl by stimulating the samples using pulsed blue LEDs at different temperatures between 50 and 250 0 C after beta irradiation and preheating to 280 0 C. The majority of TR-OSE signals from all the samples decayed much faster than TR-OSL signals irrespective of the stimulation temperatures. This suggests that the lifetime of OSL in these dosimeters arises mainly from the relaxation of an excited state of the recombination centre, rather than from residence time of an electron in the conduction band.

  3. Time domain numerical calculations of the short electron bunch wakefields in resistive structures

    Energy Technology Data Exchange (ETDEWEB)

    Tsakanian, Andranik

    2010-10-15

    The acceleration of electron bunches with very small longitudinal and transverse phase space volume is one of the most actual challenges for the future International Linear Collider and high brightness X-Ray Free Electron Lasers. The exact knowledge on the wake fields generated by the ultra-short electron bunches during its interaction with surrounding structures is a very important issue to prevent the beam quality degradation and to optimize the facility performance. The high accuracy time domain numerical calculations play the decisive role in correct evaluation of the wake fields in advanced accelerators. The thesis is devoted to the development of a new longitudinally dispersion-free 3D hybrid numerical scheme in time domain for wake field calculation of ultra short bunches in structures with walls of finite conductivity. The basic approaches used in the thesis to solve the problem are the following. For materials with high but finite conductivity the model of the plane wave reflection from a conducting half-space is used. It is shown that in the conductive half-space the field components perpendicular to the interface can be neglected. The electric tangential component on the surface contributes to the tangential magnetic field in the lossless area just before the boundary layer. For high conducting media, the task is reduced to 1D electromagnetic problem in metal and the so-called 1D conducting line model can be applied instead of a full 3D space description. Further, a TE/TM (''transverse electric - transverse magnetic'') splitting implicit numerical scheme along with 1D conducting line model is applied to develop a new longitudinally dispersion-free hybrid numerical scheme in the time domain. The stability of the new hybrid numerical scheme in vacuum, conductor and bound cell is studied. The convergence of the new scheme is analyzed by comparison with the well-known analytical solutions. The wakefield calculations for a number of

  4. Forum Theater’s potential as a Research Tool

    Directory of Open Access Journals (Sweden)

    Andrea Calsamiglia Madurga

    2016-03-01

    Full Text Available We present a theoretical and epistemological reflection on Forum Theater’s potential as a Research Tool. Our presence on social action and research has led us to a double reflection on qualitative research’s limitations on the affect studies and the Forum Theater’s potential as a research tool to tackle research about affects. After some specific experiences in action research (qualitative research on romantic love and gender violence, and the creation process of the Forum Theater “Is it a joke?”, we explore Forum Theatre’s possibilities as a research tool in the feminist epistemology framework.

  5. Comments on advanced, time-resolved imaging techniques for free-electron laser (FEL) experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.

    1992-01-01

    An extensive set of time-resolved imaging experiments has been performed on rf-linac driven free-electron lasers (FELs) over the past few years. These experiments have addressed both micropulse and macropulse timescales on both the charged-particle beam and the wiggler/undulator outputs (spontaneous emission and lasing). A brief review of first measurements on photoinjecter micropulse elongation, submacropulse phase slew in drive lasers, submacropulse wavelength shifts in lasers, etc. is presented. This is followed by discussions of new measurements of 35-MeV electron beam micropulse bunch length (<10 ps) using optical transition radiation, some of the first single bend synchrotron radiation beam profile measurements at gamma <80, and comments on the low-jitter synchroscan streak camera tuner. These techniques will be further developed on the 200-650 MeV linac test stand at the Advanced Photon Source (APS) in the next few years. Such techniques should be adaptable to many of the present FEL designs and to some aspects of the next generation of light sources.

  6. Comments on advanced, time-resolved imaging techniques for free-electron laser (FEL) experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.

    1992-11-01

    An extensive set of time-resolved imaging experiments has been performed on rf-linac driven free-electron lasers (FELs) over the past few years. These experiments have addressed both micropulse and macropulse timescales on both the charged-particle beam and the wiggler/undulator outputs (spontaneous emission and lasing). A brief review of first measurements on photoinjecter micropulse elongation, submacropulse phase slew in drive lasers, submacropulse wavelength shifts in lasers, etc. is presented. This is followed by discussions of new measurements of 35-MeV electron beam micropulse bunch length (<10 ps) using optical transition radiation, some of the first single bend synchrotron radiation beam profile measurements at gamma <80, and comments on the low-jitter synchroscan streak camera tuner. These techniques will be further developed on the 200-650 MeV linac test stand at the Advanced Photon Source (APS) in the next few years. Such techniques should be adaptable to many of the present FEL designs and to some aspects of the next generation of light sources.

  7. Engaging and Assessing Students through their Electronic Devices and Real Time Quizzes

    Directory of Open Access Journals (Sweden)

    E. Ferrándiz

    2016-10-01

    Full Text Available This paper describes a teaching experience using Socrative, a third party electronic tool, for real-time questioning in lectures of Econometrics.  Econometrics is a theoretical-practical subject, but traditionally a large proportion of our students tend to focus on the practical and discard the theory, often skipping classes on theory and avoiding studying its content, probably motivated by its complexity. As a consequence, students’ marks obtained in the theoretical part of the exam are usually low. In this context, we put forward a change in our teaching methodology to include the use of Socrative, a freely available app, that allows students to answer teachers’ short, true/false, or multiple choice questions posed during each class using their smartphones (or other electronic devices with Internet connection. The objectives of this project are twofold: 1 to engage students and increase attendance at lectures; 2 to improve feedback on the learning process. The results of a survey of a sample of 186 students reveal that Socrative has been an effective tool for achieving these objectives.

  8. Time-dependent restricted-active-space self-consistent-field theory for laser-driven many-electron dynamics

    DEFF Research Database (Denmark)

    Miyagi, Haruhide; Madsen, Lars Bojer

    2013-01-01

    We present the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) theory as a framework for the time-dependent many-electron problem. The theory generalizes the multiconfigurational time-dependent Hartree-Fock (MCTDHF) theory by incorporating the restricted-active-space scheme...... well known in time-independent quantum chemistry. Optimization of the orbitals as well as the expansion coefficients at each time step makes it possible to construct the wave function accurately while using only a relatively small number of electronic configurations. In numerical calculations of high...

  9. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: Jean-Claude Landry, Department of the Interior, Agriculture and Environment, state of Geneva (right) in discussion with Peter Jenni, spokesperson for the ATLAS collaboration.

  10. Forum of Mathematics for Industry 2013

    CERN Document Server

    Anderssen, Robert; Cheng, Jin; Fukumoto, Yasuhide; McKibbin, Robert; Polthier, Konrad; Takagi, Tsuyoshi; Toh, Kim-Chuan

    2014-01-01

    This book is a collection of papers presented at the Forum “The Impact of Applications on Mathematics” in October 2013. It describes an appropriate framework in which to highlight how real-world problems, over the centuries and today, have influenced and are influencing the development of mathematics and, thereby, how mathematics is reshaped, in order to advance mathematics and its application. The contents of this book address productive and successful interaction between industry and mathematicians, as well as the cross-fertilization and collaboration that result when mathematics is involved with the advancement of science and technology.

  11. European Non Destructive Examination Forum (ENDEF)

    International Nuclear Information System (INIS)

    Deffrennes, M.; Engl, G.; Estorff, U. von

    1998-01-01

    Non destructive examination (NDE) during fabrication, Pre-service inspection (PSI) and In service inspection (ISI) are considered key issues for the safe use of nuclear energy. They are important elements of plant lifetime management which is a critical item in decision making on nuclear policies. The European non destructive examination forum (ENDEF) founded by European Commission provides a platform for open discussion between representatives of the European industries with the purpose to establish cooperation between EU, Central and Eastern European Countries and New Independent States in the field of NDE and ISI

  12. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Pictured here in front of String 2 - the full-scale test facility for LHC sytems - are (left to right) H. Wenninger, Mme M. Quirina, Mme Marie-Anne Heimo, N. Siegel, Mme Konrade Von Bremen, Prof. Roger Berthouzoz, Mme Thérèse Wolf, Prof. Dr. Med. Bernard Mach and M. Alexander Höchli.

  13. Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers

    Science.gov (United States)

    Harmand, M.; Coffee, R.; Bionta, M. R.; Chollet, M.; French, D.; Zhu, D.; Fritz, D. M.; Lemke, H. T.; Medvedev, N.; Ziaja, B.; Toleikis, S.; Cammarata, M.

    2013-03-01

    Recently, few-femtosecond pulses have become available at hard X-ray free-electron lasers. Coupled with the available sub-10 fs optical pulses, investigations into few-femtosecond dynamics are not far off. However, achieving sufficient synchronization between optical lasers and X-ray pulses continues to be challenging. We report a `measure-and-sort' approach, which achieves sub-10 fs root-mean-squared (r.m.s.) error measurement at hard X-ray FELs, far beyond the 100-200 fs r.m.s. jitter limitations. This timing diagnostic, now routinely available at the Linac Coherent Light Source (LCLS), is based on ultrafast free-carrier generation in optically transparent materials. Correlation between two independent measurements enables unambiguous demonstration of ~6 fs r.m.s. error in reporting the optical/X-ray delay, with single shot error suggesting the possibility of reaching few-femtosecond resolution.

  14. Time-resolved Chemical Imaging of Molecules by High-order Harmonics and Ultrashort Rescattering Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chii Dong [Kansas State Univ., Manhattan, KS (United States)

    2016-03-21

    Directly monitoring atomic motion during a molecular transformation with atomic-scale spatio-temporal resolution is a frontier of ultrafast optical science and physical chemistry. Here we provide the foundation for a new imaging method, fixed-angle broadband laser-induced electron scattering, based on structural retrieval by direct one-dimensional Fourier transform of a photoelectron energy distribution observed along the polarization direction of an intense ultrafast light pulse. The approach exploits the scattering of a broadband wave packet created by strong-field tunnel ionization to self-interrogate the molecular structure with picometre spatial resolution and bond specificity. With its inherent femtosecond resolution, combining our technique with molecular alignment can, in principle, provide the basis for time-resolved tomography for multi-dimensional transient structural determination.

  15. Real-time data acquisition and computation for the SSC using optical and electronic technologies

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Fenyves, E.J.; Wallace, B.

    1990-01-01

    The authors discuss combinations of optical and electronic technologies that may be able to address major data-filtering and data-analysis problems at the SSC. Novel scintillation detectors and optical readout may permit the use of optical processing techniques for trigger decisions and particle tracking. Very-high-speed fiberoptic local-area networks will be necessary to pipeline data from the detectors to the triggers and from the triggers to computers. High-speed, few-processor MIMD superconductors with advanced fiberoptic I/O technology offer a usable, cost-effective alternative to the microprocessor farms currently proposed for event selection and analysis for the SSC. The use of a real-time operating system that provides standard programming tools will facilitate all tasks, from reprogramming the detectors' event-selection criteria to detector simulation and event analysis. 34 refs., 1 fig., 1 tab

  16. Real-time electron density measurements from Cotton-Mouton effect in JET machine

    International Nuclear Information System (INIS)

    Brombin, M.; Boboc, A.; Zabeo, L.; Murari, A.

    2008-01-01

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  17. Local time, substorm, and seasonal dependence of electron precipitation at L≅4 inferred from riometer measurements

    International Nuclear Information System (INIS)

    Rosenberg, T.J.; Dudeney, J.R.

    1986-01-01

    We have examined the variations of electron precipitation at L≅4 as inferred from riometer measurements of cosmic radio noise absorption made during 1975 at Siple Station and Halley Bay, Antarctica. The results are presented in the form of annual and seasonal averages of 1/2-hourly values for two geomagnetic activity subsets, AE>140 nT (disturbed) and AE≤ 140 nT (quiet). Monthly quiet day curves were used to remove the diurnal and seasonal variations in the background noise levels. Generally, the local time characteristics of the absorption were the same at both stations; the highest absorption occurred in the 0400--1600 MLT sector during disturbed conditions and in the 1200--2000 MLT sector during quiet conditions. For high AE, the highest correlation was obtained at a lag equal to the magnetic local time difference (1.5 hours) between the two stations. On the other hand, for low AE, the highest correlation occurred for a lag of 3.0 hours, nearer the local solar time difference (3.8 hours). Consistently higher absorption was measured at Halley on the average during both levels of magnetic disturbance and in all seasons. At both locations, and for both geomagnetic activity subsets, more absorption was observed in summer and equinox than in winter. This is in contrast to earlier studies for L≥6, and suggests that a meridional reversal of seasonal behavior occurs between L = 4 and L = 6

  18. Spin-resolved electron waiting times in a quantum-dot spin valve

    Science.gov (United States)

    Tang, Gaomin; Xu, Fuming; Mi, Shuo; Wang, Jian

    2018-04-01

    We study the electronic waiting-time distributions (WTDs) in a noninteracting quantum-dot spin valve by varying spin polarization and the noncollinear angle between the magnetizations of the leads using the scattering matrix approach. Since the quantum-dot spin valve involves two channels (spin up and down) in both the incoming and outgoing channels, we study three different kinds of WTDs, which are two-channel WTD, spin-resolved single-channel WTD, and cross-channel WTD. We analyze the behaviors of WTDs in short times, correlated with the current behaviors for different spin polarizations and noncollinear angles. Cross-channel WTD reflects the correlation between two spin channels and can be used to characterize the spin-transfer torque process. We study the influence of the earlier detection on the subsequent detection from the perspective of cross-channel WTD, and define the influence degree quantity as the cumulative absolute difference between cross-channel WTDs and first-passage time distributions to quantitatively characterize the spin-flip process. We observe that influence degree versus spin-transfer torque for different noncollinear angles as well as different polarizations collapse into a single curve showing universal behaviors. This demonstrates that cross-channel WTDs can be a pathway to characterize spin correlation in spintronics system.

  19. The forums of Conimbriga and Aeminium: comparison and summary of the state of the art

    Directory of Open Access Journals (Sweden)

    Jorge de ALARCÃO

    2017-12-01

    Full Text Available This paper presents the forums of the Roman cities of Conimbriga (Condeixa-a-Velha, Portugal and Aeminium (Coimbra, Portugal, both of which date from the time of Augustus. The Aeminium forum was completely rebuilt in the time of Claudius/Nero, while the Conimbriga one was remodelled in the same period, before being demolished under the Flavians to make way for a completely new construction. This article offers a state-of-the-art comparison of the architectural models used in these two cities, based on the analysis and review of the available data, partly supplied by recent archaeological excavations. The geographic and chronological proximity of these two forums mean that it is of interest to compare their architectural design, which differ considerably in aspects such as volumetry, layout and the conceptual model used. The article discusses the proposals for the development of the Conimbriga forum and indicates an up-to-date bibliography for both public spaces, resulting, in the case of Aeminium, from a large-scale research and intervention project carried out in recent years.

  20. SmB6 electron-phonon coupling constant from time- and angle-resolved photoelectron spectroscopy

    Science.gov (United States)

    Sterzi, A.; Crepaldi, A.; Cilento, F.; Manzoni, G.; Frantzeskakis, E.; Zacchigna, M.; van Heumen, E.; Huang, Y. K.; Golden, M. S.; Parmigiani, F.

    2016-08-01

    SmB6 is a mixed valence Kondo system resulting from the hybridization between localized f electrons and delocalized d electrons. We have investigated its out-of-equilibrium electron dynamics by means of time- and angle-resolved photoelectron spectroscopy. The transient electronic population above the Fermi level can be described by a time-dependent Fermi-Dirac distribution. By solving a two-temperature model that well reproduces the relaxation dynamics of the effective electronic temperature, we estimate the electron-phonon coupling constant λ to range from 0.13 ±0.03 to 0.04 ±0.01 . These extremes are obtained assuming a coupling of the electrons with either a phonon mode at 10 or 19 meV. A realistic value of the average phonon energy will give an actual value of λ within this range. Our results provide an experimental report on the material electron-phonon coupling, contributing to both the electronic transport and the macroscopic thermodynamic properties of SmB6.

  1. Microwave measurements of the time evolution of electron density in the T-11M tokamak

    International Nuclear Information System (INIS)

    Petrov, V.G.; Petrov, A.A.; Malyshev, A.Yu.; Markov, V.K.; Babarykin, A.V.

    2004-01-01

    Unambiguous diagnostics intended for measuring the time behavior of the electron density and monitoring the line-averaged plasma density in the T-11M tokamak are described. The time behavior of the plasma density in the T-11M tokamak is measured by a multichannel phase-jump-free microwave polarization interferometer based on the Cotton-Mouton effect. After increasing the number of simultaneously operating interferometer channels and enhancing the sensitivity of measurements, it became possible to measure the time evolution of the plasma density profile in the T-11M tokamak. The first results from such measurements in various operating regimes of the T-11M tokamak are presented. The measurement and data processing techniques are described, the measurement errors are analyzed, and the results obtained are discussed. We propose using a pulsed time-of-flight refractometer to monitor the average plasma density in the T-11M tokamak. The refractometer emits nanosecond microwave probing pulses with a carrier frequency that is higher than the plasma frequency and, thus, operates in the transmission mode. A version of the instrument has been developed with a carrier frequency of 140 GHz, which allows one to measure the average density in regimes with a nominal T-11M plasma density of (3-5) x 10 13 cm -3 . Results are presented from the first measurements of the average density in the T-11M tokamak with the help of a pulsed time-of-flight refractometer by probing the plasma in the equatorial plane in a regime with the reflection of the probing radiation from the inner wall of the vacuum chamber

  2. High energy resolution and first time-dependent positron annihilation induced Auger electron spectroscopty

    International Nuclear Information System (INIS)

    Mayer, Jakob

    2010-01-01

    It was the aim of this thesis to improve the existing positron annihilation induced Auger spectrometer at the highly intense positron source NEPOMUC (NEutron induced POsitron source MUniCh) in several ways: Firstly, the measurement time for a single spectrum should be reduced from typically 12 h to roughly 1 h or even less. Secondly, the energy resolution, which amounted to ΔE/E∼10%, should be increased by at least one order of magnitude in order to make high resolution positron annihilation induced Auger spectroscopy (PAES)-measurements of Auger transitions possible and thus deliver more information about the nature of the Auger process. In order to achieve these objectives, the PAES spectrometer was equipped with a new electron energy analyzer. For its ideal operation all other components of the Auger analysis chamber had to be adapted. Particularly the sample manipulation and the positron beam guidance had to be renewed. Simulations with SIMION registered ensured the optimal positron lens parameters. After the adjustment of the new analyzer and its components, first measurements illustrated the improved performance of the PAES setup: Firstly, the measurement time for short overview measurements was reduced from 3 h to 420 s. The measurement time for more detailed Auger spectra was shortened from 12 h to 80 min. Secondly, even with the reduced measurement time, the signal to noise ratio was also enhanced by one order of magnitude. Finally, the energy resolution was improved to ΔE/E 2,3 VV-transition with PAES. Thus, within this thesis two objectives were achieved: Firstly, the PAES spectrometer was renewed and improved by at least one order of magnitude with respect to the signal to noise ratio, the measurement time and the energy resolution. Secondly, several measurements have been carried out, demonstrating the high performance of the spectrometer. Amongst them are first dynamic PAES measurements and a high resolution measurement of the CuM 2,3 VV

  3. Improving linear accelerator service response with a real- time electronic event reporting system.

    Science.gov (United States)

    Hoisak, Jeremy D P; Pawlicki, Todd; Kim, Gwe-Ya; Fletcher, Richard; Moore, Kevin L

    2014-09-08

    To track linear accelerator performance issues, an online event recording system was developed in-house for use by therapists and physicists to log the details of technical problems arising on our institution's four linear accelerators. In use since October 2010, the system was designed so that all clinical physicists would receive email notification when an event was logged. Starting in October 2012, we initiated a pilot project in collaboration with our linear accelerator vendor to explore a new model of service and support, in which event notifications were also sent electronically directly to dedicated engineers at the vendor's technical help desk, who then initiated a response to technical issues. Previously, technical issues were reported by telephone to the vendor's call center, which then disseminated information and coordinated a response with the Technical Support help desk and local service engineers. The purpose of this work was to investigate the improvements to clinical operations resulting from this new service model. The new and old service models were quantitatively compared by reviewing event logs and the oncology information system database in the nine months prior to and after initiation of the project. Here, we focus on events that resulted in an inoperative linear accelerator ("down" machine). Machine downtime, vendor response time, treatment cancellations, and event resolution were evaluated and compared over two equivalent time periods. In 389 clinical days, there were 119 machine-down events: 59 events before and 60 after introduction of the new model. In the new model, median time to service response decreased from 45 to 8 min, service engineer dispatch time decreased 44%, downtime per event decreased from 45 to 20 min, and treatment cancellations decreased 68%. The decreased vendor response time and reduced number of on-site visits by a service engineer resulted in decreased downtime and decreased patient treatment cancellations.

  4. The effect of a new intercity expressway based on travel time reliability using electronic toll collection data

    OpenAIRE

    Yamazaki, H.; Uno, N.; Kurauchi, F.

    2012-01-01

    This study describes a method of evaluating the level of service of road networks, based on the average travel time and travel time reliability using electronic toll collection (ETC) data. The authors focused on the variance in travel time under normal circumstances, thus, traffic accidents were removed from the database, and any effect of individual vehicle preference was excluded. They evaluated the travel time distribution based on the average travel time from ETC data for each 15-min inte...

  5. N-representability-driven reconstruction of the two-electron reduced-density matrix for a real-time time-dependent electronic structure method

    International Nuclear Information System (INIS)

    Jeffcoat, David B.; DePrince, A. Eugene

    2014-01-01

    Propagating the equations of motion (EOM) for the one-electron reduced-density matrix (1-RDM) requires knowledge of the corresponding two-electron RDM (2-RDM). We show that the indeterminacy of this expression can be removed through a constrained optimization that resembles the variational optimization of the ground-state 2-RDM subject to a set of known N-representability conditions. Electronic excitation energies can then be obtained by propagating the EOM for the 1-RDM and following the dipole moment after the system interacts with an oscillating external electric field. For simple systems with well-separated excited states whose symmetry differs from that of the ground state, excitation energies obtained from this method are comparable to those obtained from full configuration interaction computations. Although the optimized 2-RDM satisfies necessary N-representability conditions, the procedure cannot guarantee a unique mapping from the 1-RDM to the 2-RDM. This deficiency is evident in the mean-field-quality description of transitions to states of the same symmetry as the ground state, as well as in the inability of the method to describe Rabi oscillations

  6. N-representability-driven reconstruction of the two-electron reduced-density matrix for a real-time time-dependent electronic structure method

    Science.gov (United States)

    Jeffcoat, David B.; DePrince, A. Eugene

    2014-12-01

    Propagating the equations of motion (EOM) for the one-electron reduced-density matrix (1-RDM) requires knowledge of the corresponding two-electron RDM (2-RDM). We show that the indeterminacy of this expression can be removed through a constrained optimization that resembles the variational optimization of the ground-state 2-RDM subject to a set of known N-representability conditions. Electronic excitation energies can then be obtained by propagating the EOM for the 1-RDM and following the dipole moment after the system interacts with an oscillating external electric field. For simple systems with well-separated excited states whose symmetry differs from that of the ground state, excitation energies obtained from this method are comparable to those obtained from full configuration interaction computations. Although the optimized 2-RDM satisfies necessary N-representability conditions, the procedure cannot guarantee a unique mapping from the 1-RDM to the 2-RDM. This deficiency is evident in the mean-field-quality description of transitions to states of the same symmetry as the ground state, as well as in the inability of the method to describe Rabi oscillations.

  7. Proceedings of the driving safety technology forum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This one day forum focused on improving driving safety in the petroleum industry by introducing new technologies and strategies. The forum featured several keynote addresses on driving safety as well as the Government of Alberta's Tactical Plan and Alberta Road Safety at Work Strategy. Presentations consisted of success stories of new technology or process applications or proposed technology demonstration projects followed by question and answer panels around the following topics: industry and government strategies; driver fatigue management and prevention; driver behaviour and culture change; vehicle monitoring systems and innovative wildlife avoidance techniques. Specific presentations addressed BP's driving safety strategy, in-cabin air quality and truck drivers' health and safety and how Talisman Energy implemented oilfield fleet safety using event driven automated vehicle location technologies. A total of 3 keynote addresses, 3 panel question and answer sessions and 11 presentations were presented at the conference, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  8. European Non Destructive Examination Forum (ENDEF)

    Energy Technology Data Exchange (ETDEWEB)

    Deffrennes, M [EC, DG XVII, Nuclear Energy, Brussels (Belgium); Engl, G [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Estorff, U von [EC, JRC/IAM, Petten (Netherlands)

    1998-11-01

    ENDEF, an initiative of the European Commission, DG XVII (Energy) was well supported by the European industrial institutions working in assistance with nuclear industrial organisations in the CEEC`s (Central and Eastern European Countries) and NIS`s (New Independent States). This Forum provides effectively a platform for open discussion between representatives of industrial actors active in the NDE (Non Destructive Examination)/ISI (In Service Inspection) field with the purpose to establish a co-operation pattern between qualified representatives of the EU (European Union) industry to offer a better co-ordinated and well defined assistance to the CEEC`s and NIS in the field of NDE/ISI, and to lay the ground for further industrial co-operation. ENDEF developed a strategy to follow for the establishment of co-operation projects. This strategy is now used to understand the extent of past or present assistance projects and to identify the areas where more co-operation is needed. ENDEF encourages the creation in the NIS`s and CEEC`s of similar forums in order to increase the co-operation and co-ordination. ENDEF is also working in perfect agreement with the European Network ENIQ, piloted by the European plant operators. This identity of views lead to the leadership by the ENDEF co-ordinator of the ENIQ Task 3 involving Applications of the European Methodology for ISI qualification in the CEEC`s and NIS`s and presently fully integrated in ENDEF. (orig.)

  9. Generation 4 International Forum. 2014 Annual Report

    International Nuclear Information System (INIS)

    2015-01-01

    This eighth edition of the Generation IV International Forum (GIF) Annual Report highlights the main achievements of the Forum in 2014, and in particular progress made in the collaborative RandD activities of the eleven existing project arrangements for the six GIF systems: the gas-cooled fast reactor, the sodium-cooled fast reactor, the supercritical-water-cooled reactor and the very-high-temperature reactor. Progress made under the memoranda of understanding for the lead-cooled fast reactor and the molten salt reactor is also reported. In May 2014, China joined the supercritical-water-cooled reactor system arrangement; and in October 2014, the project arrangement on system integration and assessment for the sodium-cooled fast reactor became effective. GIF also continued to develop safety design criteria and guidelines for the sodium-cooled fast reactor, and to engage with regulators on safety approaches for generation IV systems. Finally, GIF initiated an internal discussion on sustainability approaches to complement ongoing work on economics, safety, proliferation resistance and physical protection

  10. Generation 4 International Forum. 2007 annual report

    International Nuclear Information System (INIS)

    2007-01-01

    This annual report is the first to be issued by GIF (Generation IV International Forum). It summarizes the GIF goals and accomplishments throughout 2007, describes its membership and organization, and provides an overview of its cooperation with other international endeavors for the development of nuclear energy. Future editions will focus on technical progress. Chapter 2 provides an overview on the goals of Generation IV nuclear energy systems and outlines the main characteristics of the six systems selected for joint development by GIF (VHTR - Very High Temperature Reactor; SFR - Sodium-cooled Fast Reactor; SCWR - Super-Critical Water cooled Reactor; GFR - Gas-cooled Fast Reactor; LFR - Lead-cooled Fast Reactor; and MSR - Molten Salt Reactor). Chapter 3 describes the membership and organization of the GIF, the structure of its cooperative research and development (R-D) arrangements, and the status of Member participation in these arrangements. Chapter 4 summarizes the R-D plans and achievements of the Forum until now. It highlights the R-D challenges facing the teams developing Generation IV systems and the major milestones towards the development of these systems. It also describes the progress made regarding the development of methodologies for assessing Generation IV systems with respect to the established goals. Chapter 5 reviews other major international collaborative projects in the field of nuclear energy and explains how the GIF interacts and cooperates with them. Bibliographical references are provided in each chapter in order to facilitate access to public information about the GIF objectives, goals and outcomes

  11. European Non Destructive Examination Forum (ENDEF)

    International Nuclear Information System (INIS)

    Deffrennes, M.; Engl, G.; Estorff, U. von

    1998-01-01

    ENDEF, an initiative of the European Commission, DG XVII (Energy) was well supported by the European industrial institutions working in assistance with nuclear industrial organisations in the CEEC's (Central and Eastern European Countries) and NIS's (New Independent States). This Forum provides effectively a platform for open discussion between representatives of industrial actors active in the NDE (Non Destructive Examination)/ISI (In Service Inspection) field with the purpose to establish a co-operation pattern between qualified representatives of the EU (European Union) industry to offer a better co-ordinated and well defined assistance to the CEEC's and NIS in the field of NDE/ISI, and to lay the ground for further industrial co-operation. ENDEF developed a strategy to follow for the establishment of co-operation projects. This strategy is now used to understand the extent of past or present assistance projects and to identify the areas where more co-operation is needed. ENDEF encourages the creation in the NIS's and CEEC's of similar forums in order to increase the co-operation and co-ordination. ENDEF is also working in perfect agreement with the European Network ENIQ, piloted by the European plant operators. This identity of views lead to the leadership by the ENDEF co-ordinator of the ENIQ Task 3 involving Applications of the European Methodology for ISI qualification in the CEEC's and NIS's and presently fully integrated in ENDEF. (orig.)

  12. Forum on Specifications and Design Languages 2012

    CERN Document Server

    2014-01-01

    This book brings together a selection of the best papers from the fifteenth edition of the Forum on specification and Design Languages Conference (FDL), which was held in September 2012 at Vienna University of Technology, Vienna, Austria.  FDL is a well-established international forum devoted to dissemination of research results, practical experiences and new ideas in the application of specification, design and verification languages to the design, modeling and verification of integrated circuits, complex hardware/software embedded systems, and mixed-technology systems.  ·         Covers Assertion Based Design, Verification & Debug; ·         Includes language-based modeling and design techniques for embedded systems; ·         Covers design, modeling and verification of mixed physical domain and mixed signal systems that include significant analog parts in electrical and non-electrical domains; ·         Includes formal and semi-formal system level design methods fo...

  13. Steady state and time-resolved spectroscopic investigations on the photoreactions involved within the electronically excited electron acceptor 9-cyanoanthracene in presence of benzotriazole and benzimidazole donors

    International Nuclear Information System (INIS)

    Bhattacharya, Sudeshna; Bardhan, Munmun; Ganguly, Tapan

    2010-01-01

    The electrochemical, 'steady-state' and 'time-resolved' spectroscopic investigations were made on the well-known electron acceptor 9-cyanoanthracene (CNA) when interacted with the electron donors benzotriazole (BZT) and benzimidazole (BMI) molecules. Though electrochemical measurements indicate the thermodynamical possibility of occurrences of photoinduced electron transfer reactions within these reacting systems in the lowest excited singlet state (S 1 ) of the acceptor CNA but the steady-state and time-resolved measurements clearly demonstrate only the triplet-initiated charge separation reactions. It was reported earlier that in the cases of disubstituted indole molecules the occurrences of photoinduced electron transfer reactions were apparent both in the excited singlet and triplet states of the acceptor 9-cyanoanthracene, but the similarly structured present donor molecules benzotriazole (and benzimidazole) behave differently from indoles. The weak ground state complex formations within the presently studied reacting systems appear to be responsible for the observed static quenching phenomena as evidenced from the time-resolved fluorescence studies. Time-resolved spectroscopic investigations demonstrate the formation of the ground state of the reacting components (donor and acceptor) through recombination of triplet ion-pairs via formations of contact neutral radical produced by H-abstraction mechanism.

  14. Time-dependent quantum many-body systems. Linear response, electronic transport, and reduced density matrices

    International Nuclear Information System (INIS)

    Appel, H.

    2007-05-01

    In part I of this work we present a double-pole approximation (DPA) to the response equations of time-dependent density functional theory (TDDFT). The double-pole approximation provides an exact description of systems with two strongly coupled excitations which are isolated from the rest of the spectrum. In contrast to the traditional single-pole approximation of TDDFT the DPA also yields corrections to the Kohn-Sham oscillator strengths. We also demonstrate how to invert the double-pole solution which allows us to predict matrix elements of the exchange-correlation kernel f xc from experimental input. We attempt some first steps towards a time-dependent generalization of reduced density matrix functional theory (RDMFT). In part II we derive equations of motion for natural orbitals and occupation numbers. Using the equation of motion for the occupation numbers we show that an adiabatic extension of presently known ground-state functionals of static RDMFT always leads to occupation numbers which are constant in time. From the stationary conditions of the equations of motion for the N-body correlations (correlated parts of the N-body matrices) we derive a new class of ground-state functionals which can be used in static RDMFT. Applications are presented for a one-dimensional model system where the time-dependent many-body Schroedinger equation can be propagated numerically. We use optimal control theory to find optimized laser pulses for transitions in a model for atomic Helium. From the numerically exact correlated wavefunction we extract the exact time evolution of natural orbitals and occupation numbers for (i) laser-driven Helium and (ii) electron-ion scattering. Part III of this work considers time-dependent quantum transport within TDDFT. We present an algorithm for the calculation of extended eigenstates of single-particle Hamiltonians which is especially tailored to a finite-difference discretization of the Schroedinger equation. We consider the propagation

  15. Time-dependent quantum many-body systems. Linear response, electronic transport, and reduced density matrices

    Energy Technology Data Exchange (ETDEWEB)

    Appel, H.

    2007-05-15

    In part I of this work we present a double-pole approximation (DPA) to the response equations of time-dependent density functional theory (TDDFT). The double-pole approximation provides an exact description of systems with two strongly coupled excitations which are isolated from the rest of the spectrum. In contrast to the traditional single-pole approximation of TDDFT the DPA also yields corrections to the Kohn-Sham oscillator strengths. We also demonstrate how to invert the double-pole solution which allows us to predict matrix elements of the exchange-correlation kernel f{sub xc} from experimental input. We attempt some first steps towards a time-dependent generalization of reduced density matrix functional theory (RDMFT). In part II we derive equations of motion for natural orbitals and occupation numbers. Using the equation of motion for the occupation numbers we show that an adiabatic extension of presently known ground-state functionals of static RDMFT always leads to occupation numbers which are constant in time. From the stationary conditions of the equations of motion for the N-body correlations (correlated parts of the N-body matrices) we derive a new class of ground-state functionals which can be used in static RDMFT. Applications are presented for a one-dimensional model system where the time-dependent many-body Schroedinger equation can be propagated numerically. We use optimal control theory to find optimized laser pulses for transitions in a model for atomic Helium. From the numerically exact correlated wavefunction we extract the exact time evolution of natural orbitals and occupation numbers for (i) laser-driven Helium and (ii) electron-ion scattering. Part III of this work considers time-dependent quantum transport within TDDFT. We present an algorithm for the calculation of extended eigenstates of single-particle Hamiltonians which is especially tailored to a finite-difference discretization of the Schroedinger equation. We consider the

  16. EAWAG Forum Chriesbach - A new building for aquatic research

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-02-15

    This brochure describes the 'Forum Chriesbach' - a new building for Swiss Federal Institute of Aquatic Science and Technology EAWAG that features a facade of blue glass panels that block the sun's rays in summer and let them through in winter, a highly insulating structural cladding and a ventilation system which almost needs no heating and active cooling. A photovoltaic system, which covers one third of the building's electricity requirements, a glass-roofed atrium which brings light into the building and provides night-time cooling during summer is also described. An extensively greened roof which retains rainwater, rainwater-flushed toilets with separate collection of urine, the use of environmentally compatible materials and a staff canteen with an attractive selection of organic menus are noted. The construction of the institute is briefly documented and its energy systems are described as are the materials used in its construction.

  17. An electronic system for simulation of neural networks with a micro-second real time constraint

    International Nuclear Information System (INIS)

    Chorti, Arsenia; Granado, Bertrand; Denby, Bruce; Garda, Patrick

    2001-01-01

    Neural networks implemented in hardware can perform pattern recognition very quickly, and as such have been used to advantage in the triggering systems of certain high energy physics experiments. Typically, time constants of the order of a few microseconds are required. In this paper, we present a new system. MAHARADJA, for evaluating MLP and RBF neural network paradigms in real time. The system is tested on a possible ATLAS muon triggering application suggested by the Tel Aviv ATLAS group, consisting of a 4-8-8-4 MLP which must be evaluated in 10 microseconds. The inputs to the net are dx/dz, x(z=0), dy/dz, and y(z=0), whereas the outputs give pt, tan(phi), sin(theta), and q, the charge. With a 10 MHz clock, MAHARADJA calculates the result in 6.8 microseconds; at 20 MHz, which is readily attainable, this would be reduced to only 3.4 microseconds. The system can also handle RBF networks with 3 different distance metrics (Euclidean, Manhattan and Mahalanobis), and can simulate any MLP of 10 hidden layers or less. The electronic implementation is with FPGA's, which can be optimized for a specific neural network because the number of processing elements can be modified

  18. Just-in-Time or Plenty-of-Time Teaching? Different Electronic Feedback Devices and Their Effect on Student Engagement

    Science.gov (United States)

    Sun, Jerry Chih-Yuan; Martinez, Brandon; Seli, Helena

    2014-01-01

    This study examines how incorporating different electronic feedback devices (i.e., clickers versus web-based polling) may affect specific types of student engagement (i.e., behavioral, emotional, and cognitive engagement), whether students' self-efficacy for learning and performance may differ between courses that have integrated clickers and…

  19. Neo-Nazis Sympathizers on the Forums of the Romanian Online Publications

    Directory of Open Access Journals (Sweden)

    Elena-Irina Macovei

    2013-08-01

    Full Text Available The research aims to highlight how the forums of the Romanian online publications may often become spaces for right-wing extremist propaganda. The case study includes about 1.000 comments of the readers, expressed on the articles about a protest of several intellectuals against a TV program of the Romanian public Television (TVR, where Corneliu Zelea Codreanu, the founder of the Iron Guard, a Nazi organization created in 1927, was presented as a romantic hero. The results of the content analysis of comments revealed the stigmatizing themes, the stereotypes and the extremist ideas identified on the forums of these articles. In addition, the comparison between the electronic platforms of the publications showed the importance of their features and of the characteristics of audiences regarding the content of the comments.

  20. "10th Germany at CERN" Industrial Exhibition and the first "Innovation Forum at CERN"

    CERN Multimedia

    FI Department

    2008-01-01

    On January 29-30, 2008 On 29 and 30 January 2008, the German Federal Ministry of Education and Research (BMBF) will join forces with CERN in organizing the "10th Germany at CERN" Industrial Exhibition and the first "Innovation Forum at CERN". The Industrial Exhibition provides the opportunity for some 30 German companies to present their products and services to the scientists and buyers of CERN, establish contacts and gather information on future purchasing opportunities. The main subjects will be the following: mechanical engineering, electrical engineering, electronics, civil engineering and buildings, data processing, radiation protection and vacuum and low temperature technology. The first ever "Innovation Forum at CERN" - open to all CERN Member States – will bring together under one roof researchers, innovators, and entrepreneurs to understand and discuss CERN’s applied technology. They will learn about the know-how accumulated through the LHC, the five detectors ...

  1. "10th Germany at CERN" Industrial Exhibition and the first "Innovation Forum at CERN"

    CERN Multimedia

    FI Department

    2008-01-01

    29-30 January 2008 On 29 and 30 January 2008, the German Federal Ministry of Education and Research (BMBF) will join forces with CERN in organizing the "10th Germany at CERN" Industrial Exhibition and the first "Innovation Forum at CERN". The Industrial Exhibition will provide the opportunity for some 30 German companies to present their products and services to the scientists and buyers of CERN, establish contacts and gather information on future purchasing opportunities. The main subjects will be the following: mechanical engineering, electrical engineering, electronics, civil engineering and buildings, data processing, radiation protection and vacuum and low temperature technology. The first ever "Innovation Forum at CERN" - open to all CERN Member States - will bring together under one roof researchers, innovators, and entrepreneurs to understand and discuss CERN’s applied technology. They will learn about the know-how accumulated through the LHC, the five detectors ...

  2. Online self-help forums on cannabis: A content assessment.

    Science.gov (United States)

    Greiner, Christian; Chatton, Anne; Khazaal, Yasser

    2017-10-01

    To investigate online self-help forums related to cannabis users who were searching for help on the Internet. We analyzed the content of 717 postings by 328 users in three online forums in terms of fields of interest and self-help mechanisms. Only English-language forums that were free of charge and without registration were investigated. The main self-help mechanisms were disclosure and symptoms, with relatively few posts concerning legal issues and social perceptions. The forums differed significantly in all fields of interest and self-help mechanisms except for social network and financial and vocational issues. Highly involved users more commonly posted on topics related to diagnosis, etiology/research, and provision of information and less commonly on those related to gratitude. Correlation analysis showed a moderate negative correlation between emotional support and illness-related aspects and between emotional support and exchange of information. Cannabis forums share similarities with other mental health forums. Posts differ according to user involvement and the specific orientation of the forum. The Internet offers a viable source of self-help and social support for cannabis users, which has potential clinical implications in terms of referring clients to specific forums. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Gender and Equity: Experience of the Working Women's Forum, India.

    Science.gov (United States)

    Azad, Nandini

    1996-01-01

    Illustrates how poor women were able to move out of poverty and dehumanization through a process of mobilization and organization. The process was catalyzed by the intervention of a non-governmental organization, the Working Women's Forum. Outlines the Forum's program of economic, social, and technological empowerment. (MJP)

  4. Forum Guide to Education Data Privacy. NFES 2016-096

    Science.gov (United States)

    National Forum on Education Statistics, 2016

    2016-01-01

    The National Forum on Education Statistics (Forum) organized the Education Data Privacy Working Group to explore how state and local education agencies (SEAs and LEAs) can support best practices at the school level to protect the confidentiality of student data in day-to-day instructional and administrative tasks. Many of the best practices…

  5. 77 FR 15398 - Attentive Driving: Countermeasures for Distraction Forum

    Science.gov (United States)

    2012-03-15

    ... NATIONAL TRANSPORTATION SAFETY BOARD Attentive Driving: Countermeasures for Distraction Forum The National Transportation Safety Board (NTSB) will convene a forum, Attentive Driving: Countermeasures for... a period of 3 months from the date of the event. Distracted driving is a serious safety risk on our...

  6. Global Forum for Health Research 2008-2009 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Since its foundation in 1998, the Global Forum for Health Research (GFHR) has sought to focus greater attention and resources on research that will improve the health of the poor, marginalized and disadvantaged. The Forum has also become an authoritative and independent source of reliable data, practical tools and ...

  7. The Environmental and Ecological Forum 1970-1971.

    Science.gov (United States)

    Atomic Energy Commission, Washington, DC. Office of Information Services.

    This report contains the papers presented in the 1970-1971 Environmental and Ecological Forum series, planned to provide an overview of the significant environmental, social, and economic aspects of electric power generation, more specifically, the pros and cons of nuclear power production. The Forum was organized as a public service to foster…

  8. The Madikwe Forum: a comprehensive partnership for supporting ...

    African Journals Online (AJOL)

    This article presents findings from a qualitative study of a governance structure of the African Comprehensive HIV/AIDS Partnerships (ACHAP), namely the Madikwe Forum. The investigation sought to critically reflect on the role and effectiveness of the Madikwe Forum in Botswana's response to HIV and AIDS and to ...

  9. Practicing Multilingual Identities: Online Interactions in a Korean Dramas Forum

    Science.gov (United States)

    Kim, Grace MyHyun

    2016-01-01

    This article presents the language practices of global youth who populate an online discussion forum devoted to Korea-produced dramas. Qualitative data included the writing, visual images, and interactions created within the forum. Findings revealed youth from geographically disparate places using new media affordances to engage with a minority…

  10. 10. national workshop of the NEA Forum on Stakeholder Confidence

    International Nuclear Information System (INIS)

    Martin, Kamishan; )

    2017-01-01

    The Forum on Stakeholder Confidence (FSC) was established by the NEA Radioactive Waste Management Committee (RWMC) in the year 2000. It fosters learning about stakeholder dialogue and ways to develop shared confidence, informed consent and acceptance of radioactive waste (RW) management solutions. A 'stakeholder' is defined as anyone with a role to play or an interest in the process of deciding about RW management. The FSC provides a setting for direct stakeholder exchange in an atmosphere of mutual respect and learning. Participating in this forum are government policy and regulatory officials, R and D specialists, implementers, and industry representatives from NEA member countries. Together they analyse, document and provide recommendations on today's and tomorrow's processes for embedding waste management programs into a socio-political decision-making context. The FSC convenes annually for a regular meeting and is often complemented by an FSC national workshop. The regular meetings include lectures and topical case study sessions to share experiences. FSC national workshops are organised in volunteer NEA member countries to bring together all the national stakeholders to provide a neutral ground for discussion, dialogue and advancement of knowledge on long-term radioactive waste management. FSC members and other international actors involved in RW management are invited to learn about the host country's waste management program and provide support by giving an external reflection built up on their own experience. They are often supplemented by a half a day devoted to a community visit (potential or selected site for a repository) or open event (public meeting or debate). 2016 marked the 10. national workshop of the FSC which took place in Switzerland. It focused on 'Bridging Gaps - Developing Sustainable Inter-generational Decision-making in Radioactive Waste Management'. The workshop provided a forum for the participants from around the world to learn from

  11. The development of the Asian Forum for Polar Sciences (AFoPS)

    Science.gov (United States)

    Kim, Yeadong; Jeong, Jihoon

    2015-12-01

    The Asian Forum for Polar Sciences (AFoPS), an international forum of Asian polar research institutes, was established for the advancement of polar sciences among its members in 2004. The Forum has served as an important medium of Asian collective endeavors for polar affairs in human and information exchange, research collaboration, and logistics cooperation for the last decade. The historical development of the AFoPS in retrospect can be divided into four phases: inception and establishment (2003-2004), growth and expansion (2005-2007), review and restructuring (2008-2011), and achievements and further measures (2012-2014). The progress of the AFoPS has not been linear and this trend will continue into the next decades. The Forum, however, clearly made achievements in this period of time, realizing multilateral research and logistics cooperation that would have been previously unimaginable; by doing so, it has laid the foundation for the future. Responsible for a great portion of the world's polar activities, the AFoPS will rise to meet the expectations of the world by producing notable research output, initiating international cooperative programs, and supporting non-polar Asian countries with education and research collaboration. These are the tasks of the AFoPS for the next decade and they require strategy that promotes and facilitates collaboration in a practical way and draws attention of non-polar Asian countries to the polar sciences.

  12. Electron mobilities of n-type organic semiconductors from time-dependent wavepacket diffusion method: pentacenequinone derivatives.

    Science.gov (United States)

    Zhang, WeiWei; Zhong, XinXin; Zhao, Yi

    2012-11-26

    The electron mobilities of two n-type pentacenequinone derivative organic semiconductors, 5,7,12,14-tetraaza-6,13-pentacenequinone (TAPQ5) and 1,4,8,11-tetraaza-6,13-pentacenequinone (TAPQ7), are investigated with use of the methods of electronic structure and quantum dynamics. The electronic structure calculations reveal that the two key parameters for the control of electron transfer, reorganization energy and electronic coupling, are similar for these two isomerization systems, and the charge carriers essentially display one-dimensional transport properties. The mobilities are then calculated by using the time-dependent wavepacket diffusion approach in which the dynamic fluctuations of the electronic couplings are incorporated via their correlation functions obtained from molecular dynamics simulations. The predicted mobility of TAPQ7 crystal is about six times larger than that of TAPQ5 crystal. Most interestingly, Fermi's golden rule predicts the mobilities very close to those from the time-dependent wavepacket diffusion method, even though the electronic couplings are explicitly large enough to make the perturbation theory invalid. The possible reason is analyzed from the dynamic fluctuations.

  13. Real-Time, Single-Shot Temporal Measurements of Short Electron Bunches, Terahertz CSR and FEL Radiation

    CERN Document Server

    Berden, G; Van der Meer, A F G

    2005-01-01

    Electro-optic detection of the Coulomb field of electron bunches is a promising technique for single-shot measurements of the bunch length and shape in the sub-picosecond time domain. This technique has been applied to the measurement of 50 MeV electron bunches in the FELIX free electron laser, showing the longitudinal profile of single bunches of around 650 fs FWHM [Phys. Rev. Lett. 93, 114802 (2004)]. The method is non-destructive and real-time, and therefore ideal for online monitoring of the longitudinal shape of single electron bunches. At FELIX we have used it for real-time optimization of sub-picosecond electron bunches. Electro-optic detection has also been used to measure the electric field profiles of far-infrared (or terahertz) optical pulses generated by the relativistic electrons. We have characterised the far-infrared output of the free electron laser, and more recently, we have measured the temporal profile of terahertz optical pulses generated at one of the bending magnets.

  14. Multiobjective Optimization for Electronic Circuit Design in Time and Frequency Domains

    Directory of Open Access Journals (Sweden)

    J. Dobes

    2013-04-01

    Full Text Available The multiobjective optimization provides an extraordinary opportunity for the finest design of electronic circuits because it allows to mathematically balance contradictory requirements together with possible constraints. In this paper, an original and substantial improvement of an existing method for the multiobjective optimization known as GAM (Goal Attainment Method is suggested. In our proposal, the GAM algorithm itself is combined with a procedure that automatically provides a set of parameters -- weights, coordinates of the reference point -- for which the method generates noninferior solutions uniformly spread over an appropriately selected part of the Pareto front. Moreover, the resulting set of obtained solutions is then presented in a suitable graphic form so that the solution representing the most satisfactory tradeoff can be easily chosen by the designer. Our system generates various types of plots that conveniently characterize results of up to four-dimensional problems. Technically, the procedures of the multiobjective optimization were created as a software add-on to the CIA (Circuit Interactive Analyzer program. This way enabled us to utilize many powerful features of this program, including the sensitivity analyses in time and frequency domains. As a result, the system is also able to perform the multiobjective optimization in the time domain and even highly nonlinear circuits can be significantly improved by our program. As a demonstration of this feature, a multiobjective optimization of a C-class power amplifier in the time domain is thoroughly described in the paper. Further, a four-dimensional optimization of a video amplifier is demonstrated with an original graphic representation of the Pareto front, and also some comparison with the weighting method is done. As an example of improving noise properties, a multiobjective optimization of a low-noise amplifier is performed, and the results in the frequency domain are shown

  15. Monitoring of quality and storage time of unsealed pasteurized milk by voltammetric electronic tongue

    International Nuclear Information System (INIS)

    Wei, Zhenbo; Wang, Jun; Zhang, Xi

    2013-01-01

    A voltammetric electronic tongue (VE-tongue) was self-developed and applied to monitor the quality and storage time of unsealed pasteurized milk. The VE-tongue comprised four working electrodes: gold, silver, platinum, and palladium electrode. Two potential waveforms: Multi-frequency rectangle pulse voltammetry (MRPV) and multi-frequency staircase pulse voltammetry (MSPV) were applied to working electrodes in the study, and both of MRPV and MSPV consisted of three frequency segments: 1 Hz, 10 Hz, and 100 Hz. The total areas under the corresponding curves obtained by VE-tongue in the three frequencies were applied as characteristic data, which were evaluated by the principal component analysis (PCA) and cluster analysis (CA). The results of PCA and CA indicate that the milk samples of different storage time could be successfully classified by the VE-tongue based on MRPV and MSPV, respectively. Combining the areas obtained by the VE-tongue based on MRPV and MSPV, the classification results of PCA and CA were improved evidently. The total bacterial count, acidity and viscosity of the milk samples were also measured during the storage, and those physicochemical characteristics showed regular configuration in PCA and CA plots. Furthermore, the total bacterial count and viscosity properties were predicted by partial least squares regression (PLSR) and least squares-support vector machines (LS-SVM), and the combination of the areas obtained by the VE-tongue based on the MRPV and MSPV were applied as the input data of PLSR and LS-SVM. Both the prediction techniques performed well in predicting viscosity and total bacterial count, and the prediction results of LS-SVM were better than that of PLSR. Those results demonstrate that the VE-tongue could be applied to monitor the quality storage time of unsealed pasteurized milk

  16. The Evolution of a Professional Practice Forum: Balancing Peer-to-Peer Learning With Course Objectives.

    Science.gov (United States)

    Janssen, Anna; Robinson, Tracy; Shaw, Tim

    2014-10-31

    The Opioid Treatment Accreditation Course (OTAC) is a mandatory accreditation requirement in New South Wales, Australia, and aims to prepare medical practitioners for the provision of safe and effective Opioid Substitution Treatment to people with opioid dependence. The course has a strong focus on safe prescribing practices and the course design includes a Professional Practice Forum that is engaging for participants and effective at imparting complex ideas and concepts that do not place additional time constraints on already time-poor health professionals. The study aimed to use participatory action research methods to develop and evaluate an online Professional Practice Forum that is a key component of the OTAC teaching and learning experience. Three evaluation cycles were implemented with three cohorts of participants (N=40) to inform the design and review of the updated OTAC course. Overall, the study relied on participatory action research methods to enhance a sense of online community and to revise the Professional Practice Forum component of the course. Findings from survey feedback and an examination of Web metrics were used to monitor participant learning and were subsequently subject to thematic analysis in order to identify key themes. The use of participatory action techniques in the redesign of the OTAC course was a successful means of engaging with participants and resulted in four revisions based on feedback from facilitators and participants. The Professional Practice Forum was rated highly and received positive feedback from both moderators and participants. The use of interactive forums in online learning in an educational module for adult learners can prove extremely valuable as a means for participants to share their expertise and improve their learning outcomes. In particular, the use of sticky and welcome threads were significant features that enhanced interactions between participants and facilitators and resulted in increased quantity and

  17. Electronic Journals, the Internet, and Scholarly Communication.

    Science.gov (United States)

    Kling, Rob; Callahan, Ewa

    2003-01-01

    Examines the role of the Internet in supporting scholarly communication via electronic journals. Topics include scholarly electronic communication; a typology of electronic journals; models of electronic documents and scholarly communication forums; publication speed; costs; pricing; access and searching; citations; interactivity; archiving and…

  18. Improvement of the intrinsic time resolving power of the Cologne iron-free orange type electron spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M.; Materna, Th.; Pascovici, G.; Christen, S.; Dewald, A.; Fransen, C.; Jolie, J.; Petkov, P.; Zell, K. O. [Institut fuer Kernphysik (IKP), Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2010-11-15

    Conversion electron spectroscopy represents an important tool for nuclear structure analysis of medium and heavy nuclei. Two iron-free magnetic electron spectrometers of the orange type have been installed at the Institute for Nuclear Physics of the University of Cologne. The very large transmission of 15% and the very good energy resolution of 1% makes the iron-free orange spectrometer a powerful instrument. By means of fast timing techniques, lifetimes of nuclear excited states can be measured with an accuracy better than 20 ps. For the first time, the energy dependent centroid position of prompt events yielding the time-walk characteristics (the prompt curve) of the orange spectrometer fast timing setup has been measured using prompt secondary {delta}-electrons generated in a pulsed beam experiment. The prompt curve calibrated as a function of energy allows precise lifetime determination down to a few tens of picoseconds by the use of the centroid shift method.

  19. Belgian nuclear forum - launching the public debate on nuclear energy

    International Nuclear Information System (INIS)

    Leclere, Robert; Van Landeghem, Yves

    2010-01-01

    In the past decades, public opinion on nuclear power was dominated by a 'sleeping', indifferent majority. Nothing moved until (a minority of) opponents began to stir. Their activism strongly contrasted with the low-profile attitude of the nuclear players and pushed a considerable part of the indifferent majority towards a more negative attitude. A 2007 opinion poll (IFOP) confirmed this trend. The poll also revealed a major lack of objective and factual information. Incorrect and incomplete arguments tended to demonize nuclear energy, and 'nuclear' became a brand polarizing public opinion. This had a negative impact on decision-makers and culminated in the Belgian phase-out law of 2003. Based on the opinion poll, the members of the Belgian Nuclear Forum decided to launch a public information campaign, which they would jointly finance, with these goals: - In 3 to 4 years time, create greater public awareness on energy matters and move public opinion towards a more positive attitude. - Gain recognition of nuclear energy's legitimate place in the mix, and of the importance of peaceful nuclear applications. - Attract attention to the Belgian know-how and the importance of the industry on the scientific and economical level. - Optimize conditions for important nuclear issues such as long-term operation of NPPs, new nuclear research projects (MYRRHA),.. A 'push-pull' approach was adopted: push communication to the public (campaign) to pull (involve) decision-makers and get nuclear back on the political agenda. The Forum also opted for a sustained, long-term effort based on public campaigning, public relations and public affairs. Considering its long-time absence from the public debate, the Forum and its agency Saatchi and Saatchi agreed upon the following principles to underpin the campaign: - No 'pro-campaign'; that would be highly unrealistic and have a negative effect; - No taboos: bring up both the pros and cons; - No emotions: bring reason into a mainly emotional

  20. Comparison of the Mercury and earth magnetospheres - electron measurements and substorm time scales

    International Nuclear Information System (INIS)

    Christon, S.P.

    1987-01-01

    The present search for similarities between earth and Mercury plasma electron distribution and large-scale dynamics notes that both spectral shapes are similar to a kappa-distribution. A model distribution of this type which incorporates convective flow is used to simulate the observed plasma electron spectral variations near the Mariner 10-Mercury 1 A event; convection appears to be stronger before, rather than during, the A event, in contradiction to the Baker (1986) convective injection model for Mercury's two relativistic electron flux enhancements. Mercury's postmidnight energetic electron B and B-prime events seem to be multiple onsets in the course of a substorm. 65 references

  1. Altitude distribution of electron concentration in ionospheric D-region in presence of time-varying solar radiation flux

    International Nuclear Information System (INIS)

    Nina, A.; Čadež, V.; Srećković, V.; Šulić, D.

    2012-01-01

    In this paper, we study the influence of solar flares on electron concentration in the terrestrial ionospheric D-region by analyzing the amplitude and phase time variations of very low frequency (VLF) radio waves emitted by DHO transmitter (Germany) and recorded by the AWESOME receiver in Belgrade (Serbia) in real time. The rise of photo-ionization rate in the ionospheric D-region is a typical consequence of solar flare activity as recorded by GOES-15 satellite for the event on March 24, 2011 between 12:01 UT and 12:11 UT. At altitudes around 70 km, the photo-ionization and recombination are the dominant electron gain and electron loss processes, respectively. We analyze the relative contribution of each of these two processes in the resulting electron concentration variation in perturbed ionosphere.

  2. Altitude distribution of electron concentration in ionospheric D-region in presence of time-varying solar radiation flux

    Energy Technology Data Exchange (ETDEWEB)

    Nina, A., E-mail: sandrast@ipb.ac.rs [Institute of Physics, University of Belgrade, P.O. Box 57, Belgrade (Serbia); Cadez, V. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia); Sreckovic, V. [Institute of Physics, University of Belgrade, P.O. Box 57, Belgrade (Serbia); Sulic, D. [Faculty of Ecology and Environmental Protection, Union - Nikola Tesla University, Cara Dusana 62, 11000 Belgrade (Serbia)

    2012-05-15

    In this paper, we study the influence of solar flares on electron concentration in the terrestrial ionospheric D-region by analyzing the amplitude and phase time variations of very low frequency (VLF) radio waves emitted by DHO transmitter (Germany) and recorded by the AWESOME receiver in Belgrade (Serbia) in real time. The rise of photo-ionization rate in the ionospheric D-region is a typical consequence of solar flare activity as recorded by GOES-15 satellite for the event on March 24, 2011 between 12:01 UT and 12:11 UT. At altitudes around 70 km, the photo-ionization and recombination are the dominant electron gain and electron loss processes, respectively. We analyze the relative contribution of each of these two processes in the resulting electron concentration variation in perturbed ionosphere.

  3. The Regulatory Cooperation Forum, an Opportunity to Strengthen International Cooperation

    International Nuclear Information System (INIS)

    Lachaume, J.L.; Mamoru, M.

    2016-01-01

    The Regulatory Cooperation Forum (RCF) is a member-driven forum of nuclear power regulators created in 2010 that promotes the sharing of regulatory knowledge and experience through international cooperation and collaboration using the IAEA Safety Standards as its basis. The RCF involves countries with advanced nuclear power programmes, countries embarking on nuclear power for the first time and countries with smaller programmes considering expansion. The primary objectives of the RCF are: • To promote collaboration and cooperation among RCF members to improve coordination of support for regulatory infrastructure development; • To contribute to achieving and sustaining a high level of nuclear safety, consistent with the IAEA Safety Standards and Guidance; • To optimize resources among RCF members and avoid unnecessary support duplication through improved coordination. Membership of the RCF is open to all Member States of the IAEA. Participants in RCF activities will normally be senior representatives from regulatory bodies in Member States and from other providers, including the IAEA, European Commission (EC) and the Nuclear Energy Agency (NEA) of the Organization for Economic Co-operation and Development (OECD). So far, more than 30 countries are members of the RCF. The RCF has developed Action Plans to support Jordan, Vietnam, Belarus and Poland. The IAEA’s Nuclear Safety Action Plan urges Member States to strengthen the effectiveness of national regulatory bodies as well as base the development of their nuclear infrastructures on IAEA Safety Standards. The RCF assists Member States in implementing both of these actions for embarking, existing and expanding nuclear programmes. (author)

  4. Ribosome dynamics and tRNA movement by time-resolved electron cryomicroscopy.

    Science.gov (United States)

    Fischer, Niels; Konevega, Andrey L; Wintermeyer, Wolfgang; Rodnina, Marina V; Stark, Holger

    2010-07-15

    The translocation step of protein synthesis entails large-scale rearrangements of the ribosome-transfer RNA (tRNA) complex. Here we have followed tRNA movement through the ribosome during translocation by time-resolved single-particle electron cryomicroscopy (cryo-EM). Unbiased computational sorting of cryo-EM images yielded 50 distinct three-dimensional reconstructions, showing the tRNAs in classical, hybrid and various novel intermediate states that provide trajectories and kinetic information about tRNA movement through the ribosome. The structures indicate how tRNA movement is coupled with global and local conformational changes of the ribosome, in particular of the head and body of the small ribosomal subunit, and show that dynamic interactions between tRNAs and ribosomal residues confine the path of the tRNAs through the ribosome. The temperature dependence of ribosome dynamics reveals a surprisingly flat energy landscape of conformational variations at physiological temperature. The ribosome functions as a Brownian machine that couples spontaneous conformational changes driven by thermal energy to directed movement.

  5. Real-time transmission electron microscope observation of gold nanoclusters diffusing into silicon at room temperature

    International Nuclear Information System (INIS)

    Ishida, Tadashi; Nakajima, Yuuki; Fujita, Hiroyuki; Endo, Junji; Collard, Dominique

    2009-01-01

    Gold diffusion into silicon at room temperature was observed in real time with atomic resolution. Gold nanoclusters were formed on a silicon surface by an electrical discharge between a silicon tip and a gold coated tip inside an ultrahigh-vacuum transmission electron microscope (TEM) specimen chamber. At the moment of the gold nanocluster deposition, the gold nanoclusters had a crystalline structure. The crystalline structure gradually disappeared due to the interdiffusion between silicon and gold as observed after the deposition of gold nanoclusters. The shape of the nanocluster gradually changed due to the gold diffusion into the damaged silicon. The diffusion front between silicon and gold moved toward the silicon side. From the observations of the diffusion front, the gold diffusivity at room temperature was extracted. The extracted activation energy, 0.21 eV, matched the activation energy in bulk diffusion between damaged silicon and gold. This information is useful for optimizing the hybridization between solid-state and biological nanodevices in which gold is used as an adhesive layer between the two devices.

  6. Time dependence, complex scaling, and the calculation of resonances in many-electron systems

    International Nuclear Information System (INIS)

    Nicolaides, C.A.; Beck, D.R.

    1978-01-01

    The theory deals with certain aspects of the formal properties of atomic and molecular highly excited nonstationary states and the problem of calculating their wave functions, energies, and widths. The conceptual framework is a decay theory based on the consistent definition and calculation of the t = 0 localized state, vertical bar psi 0 >. Given this framework, the following topics are treated: The variational calculation of psi 0 and E 0 using a previously published theory that generalized the projection operator approach to many-electron systems. The exact definition of the resonance energy. The possibility of bound states in the continuum. The relation of psi 0 to the resonance (Gamow) function psi and of the Hamiltonian to the rotated Hamiltonian H(theta) based on the notion of perturbation of boundary conditions in the asymptotic region. The variational calculation of real and complex energies employing matrix elements of H and H 2 with square-integrable and resonance functions. The mathematical structure of the time evolution of vertical bar psi 0 > and the possibility of observing nonexponential decays in certain autoionizing states that are very close to the ionization threshold. A many-body theory of atomic and molecular resonances that employs the coordinate rotation method. 107 references

  7. Effect of electronic real-time prompting on hand hygiene behaviors in health care workers.

    Science.gov (United States)

    Pong, Steven; Holliday, Pamela; Fernie, Geoff

    2018-03-02

    Poor hand hygiene by health care workers is a major cause of nosocomial infections. This research evaluated the ability of an electronic monitoring system with real-time prompting capability to change hand hygiene behaviors. Handwashing activity was measured by counting dispenser activations on a single nursing unit before, during, and after installation of the system. The effect of changing the prompt duration on hand hygiene performance was determined by a cluster-randomized trial on 3 nursing units with 1 acting as control. Sustainability of performance and participation was observed on 4 nursing units over a year. All staff were eligible to participate. Between June 2015 and December 2016, a total of 459,376 hand hygiene opportunities and 330,740 handwashing events from 511 staff members were recorded. Dispenser activation counts were significantly influenced by use of the system (χ 2 [3] = 75.76; P Hand hygiene performance dropped from 62.61% to 24.94% (odds ratio, 0.36; 95% confidence interval, 0.34-0.38) when the prompting feature was removed. Staff participation had a negative trajectory of -0.72% (P Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  8. Real-time CO2 sensor for the optimal control of electronic EGR system

    Science.gov (United States)

    Kim, Gwang-jung; Choi, Byungchul; Choi, Inchul

    2013-12-01

    In modern diesel engines, EGR (Exhaust Gas Recirculation) is an important technique used in nitrogen oxide (NOx) emission reduction. This paper describes the development and experimental results of a fiber-optical sensor using a 2.7 μm wavelength absorption to quantify the simultaneous CO2 concentration which is the primary variable of EGR rate (CO2 in the exhaust gas versus CO2 in the intake gas, %). A real-time laser absorption method was developed using a DFB (distributed feedback) diode laser and waveguide to make optimal design and control of electronic EGR system required for `Euro-6' and `Tier 4 Final' NOx emission regulations. While EGR is effective to reduce NOx significantly, the amount of HC and CO is increased in the exhaust gas if EGR rate is not controlled based on driving conditions. Therefore, it is important to recirculate an appropriate amount of exhaust gas in the operation condition generating high volume of NOx. In this study, we evaluated basic characteristics and functions of our optical sensor and studied basically in order to find out optimal design condition. We demonstrated CO2 measurement speed, accuracy and linearity as making a condition similar to real engine through the bench-scale experiment.

  9. Real-time studies of battery electrochemical reactions inside a transmission electron microscope.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kevin; Hudak, Nicholas S.; Liu, Yang; Liu, Xiaohua H.; Fan, Hongyou; Subramanian, Arunkumar; Shaw, Michael J.; Sullivan, John Patrick; Huang, Jian Yu

    2012-01-01

    We report the development of new experimental capabilities and ab initio modeling for real-time studies of Li-ion battery electrochemical reactions. We developed three capabilities for in-situ transmission electron microscopy (TEM) studies: a capability that uses a nanomanipulator inside the TEM to assemble electrochemical cells with ionic liquid or solid state electrolytes, a capability that uses on-chip assembly of battery components on to TEM-compatible multi-electrode arrays, and a capability that uses a TEM-compatible sealed electrochemical cell that we developed for performing in-situ TEM using volatile battery electrolytes. These capabilities were used to understand lithiation mechanisms in nanoscale battery materials, including SnO{sub 2}, Si, Ge, Al, ZnO, and MnO{sub 2}. The modeling approaches used ab initio molecular dynamics to understand early stages of ethylene carbonate reduction on lithiated-graphite and lithium surfaces and constrained density functional theory to understand ethylene carbonate reduction on passivated electrode surfaces.

  10. Nanofriction visualized in space and time by 4D electron microscopy.

    Science.gov (United States)

    Flannigan, David J; Park, Sang Tae; Zewail, Ahmed H

    2010-11-10

    In this letter, we report a novel method of visualizing nanoscale friction in space and time using ultrafast electron microscopy (UEM). The methodology is demonstrated for a nanoscale movement of a single crystal beam on a thin amorphous membrane of silicon nitride. The movement results from the elongation of the crystal beam, which is initiated by a laser (clocking) pulse, and we examined two types of beams: those that are free of friction and the others which are fixed on the substrate. From observations of image change with time we are able to decipher the nature of microscopic friction at the solid-solid interface: smooth-sliding and periodic slip-stick friction. At the molecular and nanoscale level, and when a force parallel to the surface (expansion of the beam) is applied, the force of gravity as a (perpendicular) load cannot explain the observed friction. An additional effective load being 6 orders of magnitude larger than that due to gravity is attributed to Coulombic/van der Waals adhesion at the interface. For the case under study, metal-organic crystals, the gravitational force is on the order of piconewtons whereas the static friction force is 0.5 μN and dynamic friction is 0.4 μN; typical beam expansions are 50 nm/nJ for the free beam and 10 nm/nJ for the fixed beam. The method reported here should have applications for other materials, and for elucidating the origin of periodic and chaotic friction and their relevance to the efficacy of nano(micro)-scale devices.

  11. Forum of Mathematics for Industry 2014

    CERN Document Server

    Broadbridge, Philip; Fukumoto, Yasuhide; Kajiwara, Kenji; Takagi, Tsuyoshi; Verbitskiy, Evgeny; Wakayama, Masato

    2016-01-01

    This book is a collection of papers presented at the conference “Forum Math-for-Industry 2014” for which the unifying theme was “Applications + Practical Conceptualization + Mathematics = fruitful Innovation” in October 2014. This epigram encapsulates the dynamics of the process that takes an application through to an innovation. Industrial mathematics can be viewed as the causal engine that implements the epigram by taking an Application such as input and convolving it with a mixture of Practical Conceptualization and Mathematics to generate a fruitful Innovation as output. The book illustrates various aspects of the two-way interaction between applications and their association highlighting how practical conceptualization assists with the linking of the question that encapsulates the current application to the relevant mathematics. The contents of this volume address productive and successful interaction between industry and mathematicians, as well as the cross-fertilization and collaboration that r...

  12. 2nd academic forum: Technology and ethics

    International Nuclear Information System (INIS)

    1987-01-01

    The forum comprised two lectures on fundamental questions: - one by the philosopher Kluxen, on problems and perspectives deriving from the ethics of technology: The moral question of our responsibility for the future with the aim of safeguarding and, possibly, extending the chances of existence for all inhabitants of the earth means an added amount of technological performance; - the other by the natural scientist Schulten, on technological action measured by the yardsticks of nature: The problem is not the consumption of resources or energy, the problem is the adaptation of the environment. The adaptation of the world of technology to the environment is a task that will engender a more acute awareness of environmental responsibility in man. (HSCH) [de

  13. Ambient Assisted Living : Italian forum 2013

    CERN Document Server

    Siciliano, Pietro; Germani, Michele; Monteriù, Andrea

    2014-01-01

    This book presents the refereed proceedings of the Fourth Italian Forum on Ambient Assisted Living (AAL), held in Ancona, Italy, in October 2013. A wide range of issues are covered, and new technological developments are described which will support the autonomy and independence of individuals with special needs through an innovative and integrated approach, designed to respond to the socio-economic challenges of an aging population. Topics addressed include: health and well-being, prevention and rehabilitation, and support for care providers; active aging and its social implications; services for the frail elderly with health problems and their families; nutrition; ICT platforms/technologies for the benefit of the elderly; home automation and control technologies (autonomy, safety, and energy saving); smart cities and smart communities; telemedicine, telerehabilitation, and telecare; mobility, participation, and social inclusion; games and fun for the elderly; building design; social housing; interface desig...

  14. HP-SEE User Forum 2012

    CERN Document Server

    Karaivanova, Aneta; Oulas, Anastasis; Liabotis, Ioannis; Stojiljkovic, Danica; Prnjat, Ognjen

    2014-01-01

    This book is a collection of carefully reviewed papers presented during the HP-SEE User Forum, the meeting of the High-Performance Computing Infrastructure for South East Europe’s (HP-SEE) Research Communities, held in October 17-19, 2012, in Belgrade, Serbia. HP-SEE aims at supporting and integrating regional HPC infrastructures; implementing solutions for HPC in the region; and making HPC resources available to research communities in SEE, region, which are working in a number of scientific fields with specific needs for massively parallel execution on powerful computing resources. HP-SEE brings together research communities and HPC operators from 14 different countries and enables them to share HPC facilities, software, tools, data and research results, thus fostering collaboration and strengthening the regional and national human network; the project specifically supports research groups in the areas of computational physics, computational chemistry and the life sciences. The contributions presented i...

  15. Forum Math-for-Industry 2015

    CERN Document Server

    Broadbridge, Philip; Fukumoto, Yasuhide; Kamiyama, Naoyuki; Mizoguchi, Yoshihiro; Polthier, Konrad; Saeki, Osamu

    2017-01-01

    This book is a collection of papers presented at the “Forum Math-for-Industry 2015” for which the unifying theme was “The Role and Importance of Mathematics in Innovation”, held at the Institute of Mathematics for Industry, Kyushu University, October 26–30, 2015. The theme highlights two key roles that mathematics plays in supporting innovation in science, technology, and daily life, namely, needs-based and idea-based. For the former, mathematics assists with sorting through the possibilities and putting matters on a more rigorous foundation, and for the latter, mathematical models of the possible implementations play a key role. The book gives excellent examples of how mathematics assists with stimulating innovation and, thereby, highlights the importance and relevance of the concept Mathematics_FOR_Industry. The contents of this volume address productive and successful interaction between industry and mathematicians, as well as the cross-fertilization and collaboration that result when mathematics...

  16. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. He is seen here visiting building SM18, which houses String 2: the test facility for LHC systems. Photo 01: (left to right) Mme Jaconi, Prof. Roger Berthouzoz, M. Guillaume Pictet, M. Claude Bagnoud, R. Saban and Hubert Curien. Photo 02: (left to right) R. Saban, M. Jean-Claude Rochat, Hubert Curien and M. Guillaume Pictet. Photo 03: (left to right) R. Saban, M. Jean-Claude Rochat and Hubert Curien.

  17. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: (left to right) Mrs Mireille Quirina; D. Denegri, Physics Coordinator, CMS experiment; and Mrs Marisa Jaconi at the CMS detector's assembly site. In the background is the CMS magnet system under construction. The red concentric rings are part of the barrel yoke, which returns the magnetic flux generated by the superconducting coil. Supported from the innermost barrel ring is the outer cylinder of the vacuum tank that will house the superconducting coil.

  18. Members of the Forum Engelberg visit CERN

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The Forum Engelberg is an annual interdisciplinary conference held in Engelberg, Switzerland intended to act as an international platform for debate and exchange of views on key issues affecting scientific research, technology, economics and philosophy. Its President is Hubert Curien - former French Minister of Research and Space Research, and President of the CERN Council from 1994 to 1996. Photo 01: (left to right) Konrade Von Bremen, Claude-Olivier Rochat, T. Virdee and Guillaume Pictet in front of one of the two end-caps of the CMS detector at the assembly site. The brass structure in the top right-hand corner is part of the hadronic calorimeter that will measure the energy of strongly interacting particles produced in collisions at the LHC.

  19. PREFACE: Rusnanotech 2010 International Forum on Nanotechnology

    Science.gov (United States)

    Kazaryan, Konstantin

    2011-03-01

    The Rusnanotech 2010 International Forum on Nanotechnology was held from November 1-3, 2010, in Moscow, Russia. It was the third forum organized by RUSNANO (Russian Corporation of Nanotechnologies) since 2008. In March 2011 RUSNANO was established as an open joint-stock company through the reorganization of the state corporation Russian Corporation of Nanotechnologies. RUSNANO's mission is to develop the Russian nanotechnology industry through co-investment in nanotechnology projects with substantial economic potential or social benefit. Within the framework of the Forum Science and Technology Program, presentations on key trends of nanotechnology development were given by foreign and Russian scientists, R&D officers of leading international companies, universities and scientific centers. The science and technology program of the Forum was divided into eight sections as follows (by following hyperlinks you may find each section's program including videos of all oral presentations): Catalysis and Chemical Industry Nanobiotechnology Nanodiagnostics Nanoelectronics Nanomaterials Nanophotonics Nanotechnolgy In The Energy Industry Nanotechnology in Medicine The scientific program of the forum included 115 oral presentations by leading scientists from 15 countries. Among them in the "Nanomaterials" section was the lecture by Dr Konstantin Novoselov, winner of the Nobel Prize in Physics 2010. The poster session consisted of over 500 presentations, 300 of which were presented in the framework of the young scientists' nanotechnology papers competition. This volume of the Journal of Physics: Conference Series includes a selection of 57 submissions. The scientific program committee: Prof Zhores Alferov, AcademicianVice-president of Russian Academy of Sciences, Nobel Prize winner, Russia, Chairman of the Program CommitteeProf Sergey Deev, Corresponding Member of Russian Academy of SciencesHead of the Laboratory of Molecular Immunology, M M Shemyakin and Yu A Ovchinnikov

  20. Time-resolved photoelectron spectroscopy of IR-driven electron dynamics in a charge transfer model system.

    Science.gov (United States)

    Falge, Mirjam; Fröbel, Friedrich Georg; Engel, Volker; Gräfe, Stefanie

    2017-08-02

    If the adiabatic approximation is valid, electrons smoothly adapt to molecular geometry changes. In contrast, as a characteristic of diabatic dynamics, the electron density does not follow the nuclear motion. Recently, we have shown that the asymmetry in time-resolved photoelectron spectra serves as a tool to distinguish between these dynamics [Falge et al., J. Phys. Chem. Lett., 2012, 3, 2617]. Here, we investigate the influence of an additional, moderately intense infrared (IR) laser field, as often applied in attosecond time-resolved experiments, on such asymmetries. This is done using a simple model for coupled electronic-nuclear motion. We calculate time-resolved photoelectron spectra and their asymmetries and demonstrate that the spectra directly map the bound electron-nuclear dynamics. From the asymmetries, we can trace the IR field-induced population transfer and both the field-driven and intrinsic (non-)adiabatic dynamics. This holds true when considering superposition states accompanied by electronic coherences. The latter are observable in the asymmetries for sufficiently short XUV pulses to coherently probe the coupled states. It is thus documented that the asymmetry is a measure for phases in bound electron wave packets and non-adiabatic dynamics.

  1. London forum targets Africa's cancer crisis

    International Nuclear Information System (INIS)

    2007-01-01

    Full text: Africa stands on the brink of a cancer epidemic, with more than a million new cases a year by 2020. Raising awareness of the threat is one of the biggest challenges facing the global health community today. Finding solutions is an even greater one. The University of Oxford's Africa-Oxford Cancer Consortium (AfrOx), together with the International Atomic Energy Agency (IAEA), is assembling some of the world's most prominent cancer experts and policymakers in London, UK, on 10-11 May, 2007, to take up the challenge. Cancer care services in Africa are desperately limited. Life-saving radiotherapy, which is used effectively on more than 50% of cancer patients in the developed world, is available in only 21 of Africa's 53 countries, or to less than 20% of the total population. Lack of resources and basic infrastructure mean that millions of people have no access to cancer screening, early diagnosis, treatment or palliative care. Moreover, nearly 45% of cancer deaths in Africa are due to rampant viral infection, poor nutrition and widespread tobacco use. 'Many lives in Africa could be saved through prevention strategies and investments in comprehensive cancer control,' says Massoud Samiei, Head of the IAEA's Programme of Action for Cancer Therapy (PACT). 'PACT seeks to mobilize new resources and enable African countries to expand radiotherapy and cancer care in a sustainable manner.' The Cancer Control in Africa meeting will focus on Africa's deepening cancer crisis and develop strategies for much-needed national cancer control programmes. It will also act as a forum for cancer experts and health policymakers to evaluate priorities, guided by needs and available resources. By holding the meeting in London, the organizers hope to place the African problem at the forefront of the global health agenda and to enlist support and new funding from European governments to fight cancer in Africa through joint international programmes. 'We have a timely opportunity to

  2. London forum targets Africa's cancer crisis

    International Nuclear Information System (INIS)

    2007-01-01

    Full text: Africa stands on the brink of a cancer epidemic, with more than a million new cases a year by 2020. Raising awareness of the threat is one of the biggest challenges facing the global health community today. Finding solutions is an even greater one. The University of Oxford's Africa-Oxford Cancer Consortium (AfrOx), together with the International Atomic Energy Agency (IAEA), is assembling some of the world's most prominent cancer experts and policymakers in London, UK, on 10-11 May, 2007, to take up the challenge. Cancer care services in Africa are desperately limited. Life-saving radiotherapy, which is used effectively on more than 50% of cancer patients in the developed world, is available in only 21 of Africa's 53 countries, or to less than 20% of the total population. Lack of resources and basic infrastructure mean that millions of people have no access to cancer screening, early diagnosis, treatment or palliative care. Moreover, nearly 45% of cancer deaths in Africa are due to rampant viral infection, poor nutrition and widespread tobacco use. 'Many lives in Africa could be saved through prevention strategies and investments in comprehensive cancer control,' says Massoud Samiei, Head of the IAEA's Programme of Action for Cancer Therapy (PACT). 'PACT seeks to mobilize new resources and enable African countries to expand radiotherapy and cancer care in a sustainable manner.' The Cancer Control in Africa meeting will focus on Africa's deepening cancer crisis and develop strategies for much-needed national cancer control programmes. It will also act as a forum for cancer experts and health policymakers to evaluate priorities, guided by needs and available resources. By holding the meeting in London, the organizers hope to place the African problem at the forefront of the global health agenda and to enlist support and new funding from European governments to fight cancer in Africa through joint international programmes. 'We have a timely opportunity to

  3. Electron spin echo studies of the internal motion of radicals in crystals: Phase memory vs correlation time

    International Nuclear Information System (INIS)

    Kispert, L.D.; Bowman, M.K.; Norris, J.R.; Brown, M.S.

    1982-01-01

    An electron spin echo (ESE) study of the internal motion of the CH 2 protons in irradiated zinc acetate dihydrate crystals shows that quantitative measurements of the motional correlation time can be obtained quite directly from pulsed measurements. In the slow motional limit, the motional correlation time is equal to the phase memory time determined by ESE. In the fast motional limit, the motional correlation time is proportional to the no motion spectral second moment divided by the ESE phase memory time. ESE offers a convenient method of studying motion, electron transfer, conductivity, etc. in a variety of systems too complicated for study by ordinary EPR. New systems for study by ESE include biological samples, organic polymers, liquid solutions of radicals with unresolved hyperfine, etc. When motion modulates large anisotropic hyperfine couplings, ESE measurements of the phase memory time are sensitive to modulation of pseudosecular hyperfine interactions

  4. Time for a forum on terms used for textile fibers

    Directory of Open Access Journals (Sweden)

    Zawistoski, P. S.

    2012-11-01

    Full Text Available The advances in manufactured fibers and textiles have garnered interest and excitement of textile artists and consumers alike for a myriad of reasons, including health, environmental, and fashion. The chemical and molecular nature of these advances, however leads to confusion and misunderstanding of the new fibers in the materials. This is exacerbated by the current climate of distrust for chemical words and desire for "green" products and the unregulated (misinformation and marketing on the web. Textile artists, consumers, and the clothing and household textile industry need clear names and labels to identify the materials they are using.

  5. Time resolved, 2-D hard X-ray imaging of relativistic electron-beam target interactions on ETA-II

    International Nuclear Information System (INIS)

    Crist, C.E.; Sampayan, S.; Westenskow, G.; Caporaso, G.; Houck, T.; Weir, J.; Trimble, D.; Krogh, M.

    1998-01-01

    Advanced radiographic applications require a constant source size less than 1 mm. To study the time history of a relativistic electron beam as it interacts with a bremsstrahlung converter, one of the diagnostics they use is a multi-frame time-resolved hard x-ray camera. They are performing experiments on the ETA-II accelerator at Lawrence Livermore National Laboratory to investigate details of the electron beam/converter interactions. The camera they are using contains 6 time-resolved images, each image is a 5 ns frame. By starting each successive frame 10 ns after the previous frame, they create a 6-frame movie from the hard x-rays produced from the interaction of the 50-ns electron beam pulse

  6. Can Online Forums Be Designed to Empower Local Communities?

    Directory of Open Access Journals (Sweden)

    Kerill Dunne

    2011-07-01

    Full Text Available There has been a growing concern regarding political disengagement among citizens within western representative democracies. This concern has brought about calls for local communities to be empowered by giving citizens more control over local decision making. The objective of this paper is to examine if local political online forums can be built to empower local communities. That is to say, this paper will test if the E-Democracy.org’s Local Issues Forum Guidebook recommendations (A to do list for building successful online forums actually work and produce forums which facilitate citizens to have a greater say on local decision making and thus, induce empowerment. In order to test these recommendations a two-pronged methodological approach was taken. Firstly, using these recommendations an online forum was constructed in-conjunction with a local authority within the UK. Secondly, the recommendations were tested again except in this second approach a sample of online forums from around the world was examined. This paper argues that the E-Democracy.org’s recommendations do not always produce forums which empower local communities - Based on lessons learned from both experiments new guidelines are provided.

  7. Can anonymous posters on medical forums be reidentified?

    Science.gov (United States)

    Bobicev, Victoria; Sokolova, Marina; El Emam, Khaled; Jafer, Yasser; Dewar, Brian; Jonker, Elizabeth; Matwin, Stan

    2013-10-03

    Participants in medical forums often reveal personal health information about themselves in their online postings. To feel comfortable revealing sensitive personal health information, some participants may hide their identity by posting anonymously. They can do this by using fake identities, nicknames, or pseudonyms that cannot readily be traced back to them. However, individual writing styles have unique features and it may be possible to determine the true identity of an anonymous user through author attribution analysis. Although there has been previous work on the authorship attribution problem, there has been a dearth of research on automated authorship attribution on medical forums. The focus of the paper is to demonstrate that character-based author attribution works better than word-based methods in medical forums. The goal was to build a system that accurately attributes authorship of messages posted on medical forums. The Authorship Attributor system uses text analysis techniques to crawl medical forums and automatically correlate messages written by the same authors. Authorship Attributor processes unstructured texts regardless of the document type, context, and content. The messages were labeled by nicknames of the forum participants. We evaluated the system's performance through its accuracy on 6000 messages gathered from 2 medical forums on an in vitro fertilization (IVF) support website. Given 2 lists of candidate authors (30 and 50 candidates, respectively), we obtained an F score accuracy in detecting authors of 75% to 80% on messages containing 100 to 150 words on average, and 97.9% on longer messages containing at least 300 words. Authorship can be successfully detected in short free-form messages posted on medical forums. This raises a concern about the meaningfulness of anonymous posting on such medical forums. Authorship attribution tools can be used to warn consumers wishing to post anonymously about the likelihood of their identity being

  8. Influence of time-periodic potentials on electronic transport in double-well structure

    International Nuclear Information System (INIS)

    Chun-Lei, Li; Yan, Xu

    2010-01-01

    Within the framework of the Floquet theorem, we have investigated single-electron photon-assisted tunneling in a double-well system using the transfer matrix technique. The transmission probability displays satellite peaks on both sides of the main resonance peaks and these satellite peaks originate from emission or absorption photons. The single-electron resonance tunneling can be controlled through changing the applied harmonically potential positions, such as driven potential in wells, in barriers, or in whole double-well systems. This advantage should be useful in the optimization of the parameters of a transmission device. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. Effect of a Real-Time Electronic Dashboard on a Rapid Response System.

    Science.gov (United States)

    Fletcher, Grant S; Aaronson, Barry A; White, Andrew A; Julka, Reena

    2017-11-20

    A rapid response system (RRS) may have limited effectiveness when inpatient providers fail to recognize signs of early patient decompensation. We evaluated the impact of an electronic medical record (EMR)-based alerting dashboard on outcomes associated with RRS activation. We used a repeated treatment study in which the dashboard display was successively turned on and off each week for ten 2-week cycles over a 20-week period on the inpatient acute care wards of an academic medical center. The Rapid Response Team (RRT) dashboard displayed all hospital patients in a single view ranked by severity score, updated in real time. The dashboard could be seen within the EMR by any provider, including RRT members. The primary outcomes were the incidence rate ratio (IRR) of all RRT activations, unexpected ICU transfers, cardiopulmonary arrests and deaths on general medical-surgical wards (wards). We conducted an exploratory analysis of first RRT activations. There were 6736 eligible admissions during the 20-week study period. There was no change in overall RRT activations (IRR = 1.14, p = 0.07), but a significant increase in first RRT activations (IRR = 1.20, p = 0.04). There were no significant differences in unexpected ICU transfers (IRR = 1.15, p = 0.25), cardiopulmonary arrests on general wards (IRR = 1.46, p = 0.43), or deaths on general wards (IRR = 0.96, p = 0.89). The introduction of the RRT dashboard was associated with increased initial RRT activations but not overall activations, unexpected ICU transfers, cardiopulmonary arrests, or death. The RRT dashboard is a novel tool to help providers recognize patient decompensation and may improve initial RRT notification.

  10. Storm-time total electron content and its response to penetration electric fields over South America

    Directory of Open Access Journals (Sweden)

    P. M. de Siqueira

    2011-10-01

    Full Text Available In this work the response of the ionosphere due to the severe magnetic storm of 7–10 November 2004 is investigated by analyzing GPS Total Electron Content (TEC maps constructed for the South America sector. In order to verify the disturbed zonal electric fields in South America during the superstorm, ionospheric vertical drift data obtained from modeling results are used in the analysis. The vertical drifts were inferred from ΔH magnetometer data (Jicamarca-Piura following the methodology presented by Anderson et al. (2004. Also used were vertical drifts measured by the Jicamarca ISR. Data from a digisonde located at São Luís, Brazil (2.33° S, 44.2° W, dip latitude 0.25° are presented to complement the Jicamarca equatorial data. Penetration electric fields were observed by the comparison between the equatorial vertical drifts and the Interplanetary Electric Field (IEF. The TEC maps obtained from GPS data reflect the ionospheric response over the South America low-latitude and equatorial region. They reveal unexpected plasma distributions and TEC levels during the main phase of the superstorm on 7 November, which is coincident with the local post-sunset hours. At this time an increase in the pre-reversal enhancement was expected to develop the Equatorial Ionization Anomaly (EIA but we observed the absence of EIA. The results also reveal well known characteristics of the plasma distributions on 8, 9, and 10 November. The emphasized features are the expansion and intensification of EIA due to prompt penetration electric fields on 9 November and the inhibition of EIA during post-sunset hours on 7, 8, and 10 November. One important result is that the TEC maps provided a bi-dimensional view of the ionospheric changes offering a spatial description of the electrodynamics involved, which is an advantage over TEC measured by isolated GPS receivers.

  11. On the classical Maxwell-Lorentz electrodynamics, the electron inertia problem, and the Feynman proper time paradigm

    International Nuclear Information System (INIS)

    Prykarpatsky, A.K.; Bogolubov, J.R.

    2016-01-01

    The classical Maxwell electromagnetic field and the Lorentz-type force equations are rederived in the framework of the Feynman proper time paradigm and the related vacuum field theory approach. The classical Ampere law origin is rederived, and its relationship with the Feynman proper time paradigm is discussed. The electron inertia problem is analyzed in detail within the Lagrangian and Hamiltonian formalisms and the related pressure-energy compensation principle of stochastic electrodynamics. The modified Abraham-Lorentz damping radiation force is derived and the electromagnetic electron mass origin is argued

  12. Time-dependent first-principles study of angle-resolved secondary electron emission from atomic sheets

    Science.gov (United States)

    Ueda, Yoshihiro; Suzuki, Yasumitsu; Watanabe, Kazuyuki

    2018-02-01

    Angle-resolved secondary electron emission (ARSEE) spectra were analyzed for two-dimensional atomic sheets using a time-dependent first-principles simulation of electron scattering. We demonstrate that the calculated ARSEE spectra capture the unoccupied band structure of the atomic sheets. The excitation dynamics that lead to SEE have also been revealed by the time-dependent Kohn-Sham decomposition scheme. In the present study, the mechanism for the experimentally observed ARSEE from atomic sheets is elucidated with respect to both energetics and the dynamical aspects of SEE.

  13. HC Forum®: a web site based on an international human cytogenetic database

    Science.gov (United States)

    Cohen, Olivier; Mermet, Marie-Ange; Demongeot, Jacques

    2001-01-01

    Familial structural rearrangements of chromosomes represent a factor of malformation risk that could vary over a large range, making genetic counseling difficult. However, they also represent a powerful tool for increasing knowledge of the genome, particularly by studying breakpoints and viable imbalances of the genome. We have developed a collaborative database that now includes data on more than 4100 families, from which we have developed a web site called HC Forum® (http://HCForum.imag.fr). It offers geneticists assistance in diagnosis and in genetic counseling by assessing the malformation risk with statistical models. For researchers, interactive interfaces exhibit the distribution of chromosomal breakpoints and of the genome regions observed at birth in trisomy or in monosomy. Dedicated tools including an interactive pedigree allow electronic submission of data, which will be anonymously shown in a forum for discussions. After validation, data are definitively registered in the database with the email of the sender, allowing direct location of biological material. Thus HC Forum® constitutes a link between diagnosis laboratories and genome research centers, and after 1 year, more than 700 users from about 40 different countries already exist. PMID:11125121

  14. Analytical formulation for modulation of time-resolved dynamical Franz-Keldysh effect by electron excitation in dielectrics

    Science.gov (United States)

    Otobe, T.

    2017-12-01

    Analytical formulation of subcycle modulation (SCM) of dielectrics including electron excitation is presented. The SCM is sensitive to not only the time-resolved dynamical Franz-Keldysh effect (Tr-DFKE) [T. Otobe et al., Phys. Rev. B 93, 045124 (2016), 10.1103/PhysRevB.93.045124], which is the nonlinear response without the electron excitation, but also the excited electrons. The excited electrons enhance the modulation with even harmonics of pump laser frequency, and generate the odd-harmonics components. The new aspect of SCM is a consequence of (i) the interference between the electrons excited by the pump laser and those excited by the probe-pulse laser and (ii) oscillation of the generated wave packed by the pump laser. When the probe- and pump-pulse polarizations are parallel, the enhancement of the even harmonics and the generation of the odd-harmonics modulation appear. However, if the polarizations are orthogonal, the effect arising from the electron excitations becomes weak. By comparing the parabolic and cosine band models, I found that the electrons under the intense laser field move as quasifree particles.

  15. The annual GIS-forum in Kharkiv: tasks, thematics and indicators of development in 2012-2017

    Directory of Open Access Journals (Sweden)

    Олена Сінна

    2017-09-01

    Full Text Available The article represents the experience of organizing the international conference “GIS-forum”, which is annually held at V.N. Karazin Kharkiv National University. The main purpose of GIS-forum in 2012-2017 was to establish a constructive dialogue between distributors of software, geodata and GIS-services, providers of the equipment used in the GIS-industry, potential consumers of products, scientists, academicians who work in the field of GIS technologies, and future GIS specialists. The format of GIS-forum includes different types of events (reports, equipment exhibition, master classes, seminars, round tables, student projects contest which gives the opportunities to different specialists in geoinformatics, remote sensing, geodesy and related industries to present their interests, to discuss current state and prospects of geoinformatics development in Ukraine and the world, to assess the state of geoinformation services market, as well as the need for specialists and the requirements for their training. An important aspect of the forum is the possibility to participate both full-time, and in a remote form, which is provided by webinar broadcasting. This makes it possible to significantly expand geography of the participants. The forum was attended by representatives from the USA, Spain, Portugal, Slovakia, Estonia, Armenia, Kazakhstan, Russia, Belarus, and of course - from different cities of Ukraine (in different years, which took part in the forum either in full-time or a distance form. The key modern principles of GIS-forum organization are: integration of education, science and production in GIS-industry for the solution of common problems; democratic and flexible financial policies of the event; modernity, innovation, interdisciplinarity; teamwork to achieve goals. The expediency and success of such events are determined by the ever-growing need for training highly qualified GIS specialists, in which all participants in the process

  16. Low-Level Waste (LLW) forum meeting report

    International Nuclear Information System (INIS)

    1995-01-01

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties

  17. Forum for Almen Medicinske ph.d.-studerende

    DEFF Research Database (Denmark)

    Vedsted, Peter; Waldorff, Frans Boch; Eriksson, Tina

    Rapport fra første fællesmøde mellem nuværende og kommende almenmedicinske ph.d.-studerende. Rapporten anbefaler dannelse af et egentligt almenmedicinsk ph.d.-forum, der søges optaget i DSAM som en interessegruppe. Ph.d.-forum betragter sig som en ressource ved forskellige initiativer og ønsker...... blandt andet at arbejde for en værdig ansættelse af yngre forskere. Blandt de konkrete forslag, Ph.d.-forum har stillet, er almenmedicinske ph.d.-kurser og ph.d.-stipendium med henblik på udarbejdelse af protokol....

  18. LLW Forum meeting report, July 20--22, 1994

    International Nuclear Information System (INIS)

    1994-01-01

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representative, appointed by governors and compact commissions, established to facilitate state and compact commission implementation of the Low-Level radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The forum provides an opportunity for states and compacts to share information with one another and to exchange views with officials of federal agencies. This report details activities of the meeting held July 20-22, 1994

  19. LLW Forum meeting report, October 26--27, 1994

    International Nuclear Information System (INIS)

    1994-01-01

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties. This report details activities of the meeting held October 26-27, 1994

  20. STAIF96: space technology and applications international forum. Proceedings

    International Nuclear Information System (INIS)

    El-Genk, M.S.

    1996-01-01

    These proceedings represent papers presented at the Space Technology and Applications International Forum-STAIF. STAIF-96 hosted four technical conferences sharing the common interest in space exploration, technology, and commercialization. Topics discussed include space station, space transportation, materials processing in space, commercial forum, space power, commercial space ports, microelectronics, automation of robotics-space application, remote sensing, small business innovative research and communications. There were 243 papers presented at the forum, and 138 have been abstracted for the Energy Science and Technology database. STAIF-96 was partly sponsored by the U.S. Department of Energy

  1. LLW Forum meeting report, October 26--27, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties. This report details activities of the meeting held October 26-27, 1994.

  2. Low-Level Waste (LLW) forum meeting report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties.

  3. Online discussion forums with embedded streamed videos on distance courses

    Directory of Open Access Journals (Sweden)

    Vicenc Fernandez

    2014-03-01

    Full Text Available Existing literature on education and technology has frequently highlighted the usefulness of online discussion forums for distance courses; however, the majority of such investigations have focused their attention only on text-based forums. The objective of this paper is to determine if the embedding of streamed videos in online discussion forums generates educational dialogue and consequently the feedback that students need in a Management Accounting Course. The findings suggest some interesting issues, such as: students prefer text answers except in complex questions, and videos never replace text commentaries and explanations, but rather complement them.

  4. LLW Forum meeting report, February 13--16, 1996

    International Nuclear Information System (INIS)

    1996-01-01

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties. This report details activities at the meeting held February 13-16, 1996

  5. Analysis of Superposters' Motives for Participating in Online Forum Discussions

    Directory of Open Access Journals (Sweden)

    Irena Miljković Krečar

    2017-12-01

    Full Text Available The main aim of this study was to identify factors which motivate daily participation of extremely active online forum members. An extensive online questionnaire was constructed and sent to the Forum.hr members with more than 8,000 posts. The final sample consisted of 112 respondents. Principal components analysis provided an interpretable three components solution, explaining 54.6% of the item variance. The components were labelled as self-esteem, information exchange, and confrontation. Some significant differences were also found among motivational subscales and variables of gender, age, and the intensity of forum activity. Results are discussed in relation to previous research.

  6. Quantum screening effects on the electron-ion occurrence scattering time advance in strongly coupled semiclassical plasmas

    International Nuclear Information System (INIS)

    Song, Mi-Young; Jung, Young-Dae

    2003-01-01

    Quantum screening effects on the occurrence scattering time advance for elastic electron-ion collisions in strongly coupled semiclassical plasmas are investigated using the second-order eikonal analysis. The electron-ion interaction in strongly coupled semiclassical plasmas is obtained by the pseudopotential model taking into account the plasma screening and quantum effects. It is found that the quantum-mechanical effects significantly reduce the occurrence scattering time advance. It is also found that the occurrence scattering time advance increases with increasing Debye length. It is quite interesting to note that the domain of the maximum occurrence time advance is localized for the forward scattering case. The region of the scaled thermal de Broglie wave length (λ-bar) for the maximum occurrence time advance is found to be 0.4≤λ-bar≤1.4

  7. Free from the Constraints of Space and Time: Considering the Opportunities and Challenges for Electronic Publishing.

    Science.gov (United States)

    Eisenberg, Michael B.

    1994-01-01

    Provides a summary of the papers in this issue that deal with electronic publishing. Highlights include the impact on publishers, authors, users, and librarians and information technologists; theoretical frameworks; practical applications and implications; and future possibilities. (Contains 15 references.) (LRW)

  8. Breaking Symmetry in Time-Dependent Electronic Structure Theory to Describe Spectroscopic Properties of Non-Collinear and Chiral Molecules

    Science.gov (United States)

    Goings, Joshua James

    Time-dependent electronic structure theory has the power to predict and probe the ways electron dynamics leads to useful phenomena and spectroscopic data. Here we report several advances and extensions of broken-symmetry time-dependent electronic structure theory in order to capture the flexibility required to describe non-equilibrium spin dynamics, as well as electron dynamics for chiroptical properties and vibrational effects. In the first half, we begin by discussing the generalization of self-consistent field methods to the so-called two-component structure in order to capture non-collinear spin states. This means that individual electrons are allowed to take a superposition of spin-1/2 projection states, instead of being constrained to either spin-up or spin-down. The system is no longer a spin eigenfunction, and is known a a spin-symmetry broken wave function. This flexibility to break spin symmetry may lead to variational instabilities in the approximate wave function, and we discuss how these may be overcome. With a stable non-collinear wave function in hand, we then discuss how to obtain electronic excited states from the non-collinear reference, along with associated challenges in their physical interpretation. Finally, we extend the two-component methods to relativistic Hamiltonians, which is the proper setting for describing spin-orbit driven phenomena. We describe the first implementation of the explicit time propagation of relativistic two-component methods and how this may be used to capture spin-forbidden states in electronic absorption spectra. In the second half, we describe the extension of explicitly time-propagated wave functions to the simulation of chiroptical properties, namely circular dichroism (CD) spectra of chiral molecules. Natural circular dichroism, that is, CD in the absence of magnetic fields, originates in the broken parity symmetry of chiral molecules. This proves to be an efficient method for computing circular dichroism spectra

  9. Two-Electron Time-Delay Interference in Atomic Double Ionization by Attosecond Pulses

    International Nuclear Information System (INIS)

    Palacios, A.; Rescigno, T. N.; McCurdy, C. W.

    2009-01-01

    A two-color two-photon atomic double ionization experiment using subfemtosecond uv pulses can be designed such that the sequential two-color process dominates and one electron is ejected by each pulse. Nonetheless, ab initio calculations show that, for sufficiently short pulses, a prominent interference pattern in the joint energy distribution of the sequentially ejected electrons can be observed that is due to their indistinguishability and the exchange symmetry of the wave function.

  10. Two-electron time-delay interference in atomic double ionization by attosecond pulses

    Energy Technology Data Exchange (ETDEWEB)

    Rescigno, Thomas N

    2009-10-04

    A two-color two-photon atomic double ionization experiment using subfemtosecond UV pulses can be designed such that the sequential two-color process dominates and one electron is ejected by each pulse. Nonetheless, ab initio calculations show that, for sufficiently short pulses, a prominent interference pattern in the joint energy distribution of the sequentially ejected electrons can be observed that is due to their indistinguishability and the exchange symmetry of the wave function.

  11. Real-time visualization of the vibrational wavepacket dynamics in electronically excited pyrimidine via femtosecond time-resolved photoelectron imaging

    Science.gov (United States)

    Li, Shuai; Long, Jinyou; Ling, Fengzi; Wang, Yanmei; Song, Xinli; Zhang, Song; Zhang, Bing

    2017-07-01

    The vibrational wavepacket dynamics at the very early stages of the S1-T1 intersystem crossing in photoexcited pyrimidine is visualized in real time by femtosecond time-resolved photoelectron imaging and time-resolved mass spectroscopy. A coherent superposition of the vibrational states is prepared by the femtosecond pump pulse at 315.3 nm, resulting in a vibrational wavepacket. The composition of the prepared wavepacket is directly identified by a sustained quantum beat superimposed on the parent-ion transient, possessing a frequency in accord with the energy separation between the 6a1 and 6b2 states. The dephasing time of the vibrational wavepacket is determined to be 82 ps. More importantly, the variable Franck-Condon factors between the wavepacket components and the dispersed cation vibrational levels are experimentally illustrated to identify the dark state and follow the energy-flow dynamics on the femtosecond time scale. The time-dependent intensities of the photoelectron peaks originated from the 6a1 vibrational state exhibit a clear quantum beating pattern with similar periodicity but a phase shift of π rad with respect to those from the 6b2 state, offering an unambiguous picture of the restricted intramolecular vibrational energy redistribution dynamics in the 6a1/6b2 Fermi resonance.

  12. State of play of CME in Europe in 2014: proceedings from the Seventh Annual Meeting of the European CME Forum

    Directory of Open Access Journals (Sweden)

    Eugene Pozniak

    2015-03-01

    Full Text Available European CME Forum is a not-for-profit organisation that was established in 2007 in order to bring together all stakeholder groups with an interest in European CME and promote multi-channel discussion in an independent and neutral environment. This report summarises the presentations and discussions that took place at the 7th Annual Meeting of the European CME Forum in London on 13–14 November 2014. The meeting was held at a time of great uncertainty in European CME and gave attendees opportunity to consider many unanswered questions regarding how CME in Europe will be funded, accredited and regulated in the future. The programme for the forum was developed based on a needs assessment conducted among a variety of CME stakeholders in Europe and beyond. This exercise identified a number of issues that are rarely covered at similar gatherings and which were therefore given prominence during the meeting. Chief among these “hot topics” were how to ensure effective measurement of outcomes in CME programmes and how to encourage and manage the transparency of relationships between industry and healthcare professionals. Other subjects covered in depth during the forum included the future funding of CME, e-learning innovations and potential, and the value, or otherwise, of CME accreditation. The forum made use of a number of interactive meeting formats which ensured the days’ proceedings were characterised by a series of lively discussions and stimulating debates.

  13. QUIET-TIME SUPRATHERMAL (∼0.1–1.5 keV) ELECTRONS IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Jiawei; Wang, Linghua; Zong, Qiugang; He, Jiansen; Tu, Chuanyi [School of Earth and Space Science, Peking University, Beijing 100871 (China); Li, Gang [Department of Physics and CSPAR, University of Alabama in Huntsville, Alabama 35899 (United States); Salem, Chadi S.; Bale, Stuart D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Wimmer-Schweingruber, Robert F., E-mail: wanglhwang@gmail.com [Institute for Experimental and Applied Physics, University of Kiel, Leibnizstrasse 11, D-24118 Kiel (Germany)

    2016-03-20

    We present a statistical survey of the energy spectrum of solar wind suprathermal (∼0.1–1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ∼0.1–1.5 keV to a Kappa distribution function with an index κ and effective temperature T{sub eff}. We also calculate the number density n and average energy E{sub avg} of strahl and halo electrons by integrating the electron measurements between ∼0.1 and 1.5 keV. We find a strong positive correlation between κ and T{sub eff} for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity)

  14. Quiet-time Suprathermal (~0.1-1.5 keV) Electrons in the Solar Wind

    Science.gov (United States)

    Tao, Jiawei; Wang, Linghua; Zong, Qiugang; Li, Gang; Salem, Chadi S.; Wimmer-Schweingruber, Robert F.; He, Jiansen; Tu, Chuanyi; Bale, Stuart D.

    2016-03-01

    We present a statistical survey of the energy spectrum of solar wind suprathermal (˜0.1-1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ˜0.1-1.5 keV to a Kappa distribution function with an index κ and effective temperature Teff. We also calculate the number density n and average energy Eavg of strahl and halo electrons by integrating the electron measurements between ˜0.1 and 1.5 keV. We find a strong positive correlation between κ and Teff for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity).

  15. Time- and energy resolved photoemission electron microscopy-imaging of photoelectron time-of-flight analysis by means of pulsed excitations

    International Nuclear Information System (INIS)

    Oelsner, Andreas; Rohmer, Martin; Schneider, Christian; Bayer, Daniela; Schoenhense, Gerd; Aeschlimann, Martin

    2010-01-01

    The present work enlightens the developments in time- and energy resolved photoemission electron microscopy over the past few years. We describe basic principles of the technique and demonstrate different applications. An energy- and time-filtering photoemission electron microscopy (PEEM) for real-time spectroscopic imaging can be realized either by a retarding field or hemispherical energy analyzer or by using time-of-flight optics with a delay line detector. The latter method has the advantage of no data loss at all as all randomly incoming particles are measured not only by position but also by time. This is of particular interest for pump-probe experiments in the femtosecond and attosecond time scale where space charge processes drastically limit the maximum number of photoemitted electrons per laser pulse. This work focuses particularly on time-of-flight analysis using a novel delay line detector. Time and energy resolved PEEM instruments with delay line detectors enable 4D imaging (x, y, Δt, E Kin ) on a true counting basis. This allows a broad range of applications from real-time observation of dynamic phenomena at surfaces to fs time-of-flight spectro-microscopy and even aberration correction. By now, these time-of-flight analysis instruments achieve intrinsic time resolutions of 108 ps absolute and 13.5 ps relative. Very high permanent measurement speeds of more than 4 million events per second in random detection regimes have been realized using a standard USB2.0 interface. By means of this performance, the time-resolved PEEM technique enables to display evolutions of spatially resolved (<25 nm) and temporal sliced images life on any modern computer. The method allows dynamics investigations of variable electrical, magnetic, and optical near fields at surfaces and great prospects in dynamical adaptive photoelectron optics. For dynamical processes in the ps time scale such as magnetic domain wall movements, the time resolution of the delay line detectors

  16. Usefulness of measurement of circulation time using MgSO4 : correlation with time-density curve using electron beam computed tomography

    International Nuclear Information System (INIS)

    Kim, Byung Ki; Lee, Hui Joong; Lee, Jong Min; Kim, Yong Joo; Kang, Duck Sik

    1999-01-01

    To determine the usefulness of MgSO 4 for measuring the systemic circulation time. Systemic circulation time, defined as elapsed time from the injection of MgSO 4 solution to the point of pharyngeal burning sensation, was measured in 63 volunteers. MgSO 4 was injected into a superficial vein of an upper extremity. Using dynamic electron beam computed tomography at the level of the abdominal aorta and celiac axis, a time-intensity curve was plotted, and for these two locations, maximal enhancement time was compared. For 60 of the 63 subjects, both systemic circulation time and maximal enhancement time were determined. Average systemic circulation time was 17.4 (SD:3.6) secs. and average maximal enhancement times at the level of the abdominal aorta and celiac axis were 17.5 (SD:3.0) secs. and 18.5 (SD:3.2) secs., respectively. Correlation coefficients between systemic circulation time and maximal enhancement time for the abdominal aorta and celiac axis were 0.73 (p 4 injection and maximal enhancement time for the abdominal aorta showed significant correlation. Thus, to determine the appropriate scanning time in contrast-enhanced radiological studies, MgSO 4 can be used instead of a test bolus study

  17. CARICOF - The Caribbean Regional Climate Outlook Forum

    Science.gov (United States)

    Van Meerbeeck, Cedric

    2013-04-01

    Regional Climate Outlook Forums (RCOFs) are viewed as a critical building block in the Global Framework for Climate Services (GFCS) of the World Meteorological Organization (WMO). The GFCS seeks to extend RCOFs to all vulnerable regions of the world such as the Caribbean, of which the entire population is exposed to water- and heat-related natural hazards. An RCOF is initially intended to identify gaps in information and technical capability; facilitate research cooperation and data exchange within and between regions, and improve coordination within the climate forecasting community. A focus is given on variations in climate conditions on a seasonal timescale. In this view, the relevance of a Caribbean RCOF (CARICOF) is the following: while the seasonality of the climate in the Caribbean has been well documented, major gaps in knowledge exist in terms of the drivers in the shifts of amplitude and phase of seasons (as evidenced from the worst region-wide drought period in recent history during 2009-2010). To address those gaps, CARICOF has brought together National Weather Services (NWSs) from 18 territories under the coordination of the Caribbean Institute for Meteorology and Hydrology (CIMH), to produce region-wide, consensus, seasonal climate outlooks since March 2012. These outlooks include tercile rainfall forecasts, sea and air surface temperature forecasts as well as the likely evolution of the drivers of seasonal climate variability in the region, being amongst others the El Niño Southern Oscillation or tropical Atlantic and Caribbean Sea temperatures. Forecasts for both the national-scale forecasts made by the NWSs and CIMH's regional-scale forecast amalgamate output from several forecasting tools. These currently include: (1) statistical models such as Canonical Correlation Analysis run with the Climate Predictability Tool, providing tercile rainfall forecasts at weather station scale; (2) a global outlooks published by the WMO appointed Global Producing

  18. The performance of the ZEUS central tracking detector z-by-timing electronics in a transputer based data acquisition system

    International Nuclear Information System (INIS)

    Foster, B.; Heath, G.P.; Llewellyn, T.J.; Gingrich, D.M.; Harnew, N.; Hallam-Baker, P.M.; Khatri, T.; McArthur, I.C.; Morawitz, P.; Nash, J.; Shield, P.D.; Topp-Jorgensen, S.; Wilson, F.F.; Allen, D.B.; Carter, R.C.; Jeffs, M.D.; Morrissey, M.C.; Quinton, S.P.H.; Lane, J.B.; Postranecky, M.

    1993-01-01

    The Central Tracking Detector of the ZEUS experiment employs a time difference technique to measure the z coordinate of each hit. The method provides fast, three-dimensional space point measurements which are used as input to all levels of the ZEUS trigger. Such a tracking trigger is essential in order to discriminate against events with vertices lying outside the nominal electron-proton interaction region. Since the beam crossing interval of the HERA collider is 96 ns, all data must be pipelined through the front-end readout electronics. Subsequent data aquisition employs a novel technique which utilizes a network of approximately 120 INMOS transputers to process the data in parallel. The z-by-timing method and its data aquisition have been employed successfully in recording and reconstructing tracks from electron-proton interactions in ZEUS. (orig.)

  19. Proceedings of the Fifth Triennial Software Quality Forum 2000, Software for the Next Millennium, Software Quality Forum

    Energy Technology Data Exchange (ETDEWEB)

    Scientific Software Engineering Group, CIC-12

    2000-04-01

    The Software Quality Forum is a triennial conference held by the Software Quality Assurance Subcommittee for the Department of Energy's Quality Managers. The forum centers on key issues, information, and technology important in software development for the Nuclear Weapons Complex. This year it will be opened up to include local information technology companies and software vendors presenting their solutions, ideas, and lessons learned. The Software Quality Forum 2000 will take on a more hands-on, instructional tone than those previously held. There will be an emphasis on providing information, tools, and resources to assist developers in their goal of producing next generation software.

  20. Time-dependent view of an isotope effect in electron-nuclear nonequilibrium dynamics with applications to N2.

    Science.gov (United States)

    Ajay, Jayanth S; Komarova, Ksenia G; Remacle, Francoise; Levine, R D

    2018-05-21

    Isotopic fractionation in the photodissociation of N 2 could explain the considerable variation in the 14 N/ 15 N ratio in different regions of our galaxy. We previously proposed that such an isotope effect is due to coupling of photoexcited bound valence and Rydberg electronic states in the frequency range where there is strong state mixing. We here identify features of the role of the mass in the dynamics through a time-dependent quantum-mechanical simulation. The photoexcitation of N 2 is by an ultrashort pulse so that the process has a sharply defined origin in time and so that we can monitor the isolated molecule dynamics in time. An ultrafast pulse is necessarily broad in frequency and spans several excited electronic states. Each excited molecule is therefore not in a given electronic state but in a superposition state. A short time after excitation, there is a fairly sharp onset of a mass-dependent large population transfer when wave packets on two different electronic states in the same molecule overlap. This coherent overlap of the wave packets on different electronic states in the region of strong coupling allows an effective transfer of population that is very mass dependent. The extent of the transfer depends on the product of the populations on the two different electronic states and on their relative phase. It is as if two molecules collide but the process occurs within one molecule, a molecule that is simultaneously in both states. An analytical toy model recovers the (strong) mass and energy dependence.