Electronic resource management practical perspectives in a new technical services model

CERN Document Server

Elguindi, Anne

2012-01-01

A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

Utilization of electronic information resources by academic staff at ...

African Journals Online (AJOL)

The study investigated the utilization of Electronic Information resources by the academic staff of Makerere University in Uganda. It examined the academic staff awareness of the resources available, the types of resources provided by the Makerere University Library, the factors affecting resource utilization. The study was ...

Electronic Resources Management Project Presentation 2012

KAUST Repository

Ramli, Rindra M.

2012-01-01

This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration

Practical guide to electronic resources in the humanities

CERN Document Server

Dubnjakovic, Ana

2010-01-01

From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

Utilisation of Electronic Information Resources By Lecturers in ...

African Journals Online (AJOL)

This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

Directory of Open Access Journals (Sweden)

Sanna Torma

2004-01-01

Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

The Role of the Acquisitions Librarian in Electronic Resources Management

Science.gov (United States)

Pomerantz, Sarah B.

2010-01-01

With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

Analysis of Pedagogic Potential of Electronic Educational Resources with Elements of Autodidactics

Directory of Open Access Journals (Sweden)

Igor A.

2018-03-01

Full Text Available Introduction: in recent years didactic properties of electronic educational resources undergo considerable changes, nevertheless, the question of studying of such complete phenomenon as “an electronic educational resource with autodidactics elements” remains open, despite sufficient scientific base of researches of the terms making this concept. Article purpose – determination of essence of electronic educational resources with autodidactics elements. Materials and Methods: the main method of research was the theoretical analysis of the pedagogical and psychological literature on the problem under study. We used the theoretical (analysis, synthesis, comparison and generalization methods, the method of interpretation, pedagogical modeling, and empirical methods (observation, testing, conversation, interview, analysis of students’ performance, pedagogical experiment, peer review. Results: we detected the advantages of electronic educational resources in comparison with traditional ones. The concept of autodidactics as applied to the subject of research is considered. Properties of electronic educational resources with a linear and nonlinear principle of construction are studied.The influence of the principle of construction on the development of the learners’ qualities is shown. We formulated an integral definition of electronic educational resources with elements of autodidactics, namely, the variability, adaptivity and cyclicity of training. A model of the teaching-learning process with electronic educational resources is developed. Discussion and Conclusions: further development of a problem will allow to define whether electronic educational resources with autodidactics elements pedagogical potential for realization of educational and self-educational activity of teachers have, to modify technological procedures taking into account age features of students, their specialties and features of the organization of process of training of

Preservation and conservation of electronic information resources of ...

African Journals Online (AJOL)

The major holdings of the broadcast libraries of the Nigerian Television Authority (NTA) are electronic information resources; therefore, providing safe places for general management of these resources have aroused interest in the industry in Nigeria for sometimes. The need to study the preservation and conservation of ...

Building an electronic resource collection a practical guide

CERN Document Server

Lee, Stuart D

2004-01-01

This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

Science.gov (United States)

Shao, Fang

The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

Using XML Technologies to Organize Electronic Reference Resources

OpenAIRE

Huser, Vojtech; Del Fiol, Guilherme; Rocha, Roberto A.

2005-01-01

Provision of access to reference electronic resources to clinicians is becoming increasingly important. We have created a framework for librarians to manage access to these resources at an enterprise level, rather than at the individual hospital libraries. We describe initial project requirements, implementation details, and some preliminary results.

Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

Science.gov (United States)

Stachokas, George

2009-01-01

The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

Determining the functional form of density dependence: deductive approaches for consumer-resource systems having a single resource.

Science.gov (United States)

Abrams, Peter A

2009-09-01

Consumer-resource models are used to deduce the functional form of density dependence in the consumer population. A general approach to determining the form of consumer density dependence is proposed; this involves determining the equilibrium (or average) population size for a series of different harvest rates. The relationship between a consumer's mortality and its equilibrium population size is explored for several one-consumer/one-resource models. The shape of density dependence in the resource and the shape of the numerical and functional responses all tend to be "inherited" by the consumer's density dependence. Consumer-resource models suggest that density dependence will very often have both concave and convex segments, something that is impossible under the commonly used theta-logistic model. A range of consumer-resource models predicts that consumer population size often declines at a decelerating rate with mortality at low mortality rates, is insensitive to or increases with mortality over a wide range of intermediate mortalities, and declines at a rapidly accelerating rate with increased mortality when mortality is high. This has important implications for management and conservation of natural populations.

Electronic Resources Management System: Recommendation Report 2017

KAUST Repository

Ramli, Rindra M.

2017-01-01

This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system

The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

Science.gov (United States)

Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

2015-01-01

Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

Temperature dependent electronic conduction in semiconductors

International Nuclear Information System (INIS)

Roberts, G.G.; Munn, R.W.

1980-01-01

This review describes the temperature dependence of bulk-controlled electronic currents in semiconductors. The scope of the article is wide in that it contrasts conduction mechanisms in inorganic and organic solids and also single crystal and disordered semiconductors. In many experimental situations it is the metal-semiconductor contact or the interface between two dissimilar semiconductors that governs the temperature dependence of the conductivity. However, in order to keep the length of the review within reasonable bounds, these topics have been largely avoided and emphasis is therefore placed on bulk-limited currents. A central feature of electronic conduction in semiconductors is the concentrations of mobile electrons and holes that contribute to the conductivity. Various statistical approaches may be used to calculate these densities which are normally strongly temperature dependent. Section 1 emphasizes the relationship between the position of the Fermi level, the distribution of quantum states, the total number of electrons available and the absolute temperature of the system. The inclusion of experimental data for several materials is designed to assist the experimentalist in his interpretation of activation energy curves. Sections 2 and 3 refer to electronic conduction in disordered solids and molecular crystals, respectively. In these cases alternative approaches to the conventional band theory approach must be considered. For example, the velocities of the charge carriers are usually substantially lower than those in conventional inorganic single crystal semiconductors, thus introducing the possibility of an activated mobility. Some general electronic properties of these materials are given in the introduction to each of these sections and these help to set the conduction mechanisms in context. (orig.)

ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

Directory of Open Access Journals (Sweden)

Olena Yu. Balalaieva

2014-04-01

Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

Directory of Open Access Journals (Sweden)

Pınar Al

2003-04-01

Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

Access to electronic resources by visually impaired people

Directory of Open Access Journals (Sweden)

Jenny Craven

2003-01-01

Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

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.

Library training to promote electronic resource usage

DEFF Research Database (Denmark)

Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

2017-01-01

Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

Why and How to Measure the Use of Electronic Resources

Directory of Open Access Journals (Sweden)

Jean Bernon

2008-11-01

Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

RESEARCH OF INFLUENCE OF QUALITY OF ELECTRONIC EDUCATIONAL RESOURCES ON QUALITY OF TRAINING WITH USE OF DISTANCE TECHNOLOGIES

Directory of Open Access Journals (Sweden)

H. M. Kravtsov

2013-03-01

Full Text Available Communication improving of educational processes requires today new approaches to the management arrangements and forming of educational policy in the field of distance learning, which is based on the use of modern information and communication technologies. An important step in this process is the continuous monitoring of the development and implementation of information technology and, in particular, the distance learning systems in higher educational establishments. The main objective of the monitoring is the impact assessment on the development of distance learning following the state educational standards, curricula, methodical and technical equipment and other factors; factors revelation that influence the implementation and outcomes of distance learning; results comparison of educational institution functioning and distance education systems in order to determine the most efficient ways of its development. The paper presents the analysis results of the dependence of the quality of educational services on the electronic educational resources. Trends in educational services development was studied by comparing the quality influence of electronic educational resources on the quality of educational services of higher pedagogical educational institutions of Ukraine as of 2009-2010 and 2012-2013. Generally, the analysis of the survey results allows evaluating quality of the modern education services as satisfactory and it can be said that almost 70% of the success of their future development depends on the quality of the used electronic educational resources and distance learning systems in particular.

Euler European Libraries and Electronic Resources in Mathematical Sciences

CERN Document Server

The Euler Project. Karlsruhe

The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

OpenAIRE

Jiuh-Biing Sheu

2014-01-01

Under third-party power intervention (TPPI), which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced ...

Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

Science.gov (United States)

Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

2012-01-01

Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

Density-dependent electron transport and precise modeling of GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Bajaj, Sanyam, E-mail: bajaj.10@osu.edu; Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Reza, Shahed; Chumbes, Eduardo M. [Raytheon Integrated Defense Systems, Andover, Massachusetts 01810 (United States); Khurgin, Jacob [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Material Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

2015-10-12

We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors (HEMTs). Pulsed IV measurements established increasing electron velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10{sup 7 }cm/s at a low sheet charge density of 7.8 × 10{sup 11 }cm{sup −2}. An optical phonon emission-based electron velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the electron velocity with strong electron-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs.

Density-dependent electron transport and precise modeling of GaN high electron mobility transistors

International Nuclear Information System (INIS)

Bajaj, Sanyam; Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang; Reza, Shahed; Chumbes, Eduardo M.; Khurgin, Jacob; Rajan, Siddharth

2015-01-01

We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors (HEMTs). Pulsed IV measurements established increasing electron velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10 7  cm/s at a low sheet charge density of 7.8 × 10 11  cm −2 . An optical phonon emission-based electron velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the electron velocity with strong electron-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs

Electronic Commerce Resource Centers. An Industry--University Partnership.

Science.gov (United States)

Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

1999-01-01

Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

Electron dose dependence of signal-to-noise ratio, atom contrast and resolution in transmission electron microscope images

International Nuclear Information System (INIS)

Lee, Z.; Rose, H.; Lehtinen, O.; Biskupek, J.; Kaiser, U.

2014-01-01

In order to achieve the highest resolution in aberration-corrected (AC) high-resolution transmission electron microscopy (HRTEM) images, high electron doses are required which only a few samples can withstand. In this paper we perform dose-dependent AC-HRTEM image calculations, and study the dependence of the signal-to-noise ratio, atom contrast and resolution on electron dose and sampling. We introduce dose-dependent contrast, which can be used to evaluate the visibility of objects under different dose conditions. Based on our calculations, we determine optimum samplings for high and low electron dose imaging conditions. - Highlights: • The definition of dose-dependent atom contrast is introduced. • The dependence of the signal-to-noise ratio, atom contrast and specimen resolution on electron dose and sampling is explored. • The optimum sampling can be determined according to different dose conditions

Density-dependent electron scattering in photoexcited GaAs

DEFF Research Database (Denmark)

Mics, Zoltán; D'’Angio, Andrea; Jensen, Søren A.

2013-01-01

—In a series of systematic optical pump - terahertz probe experiments we study the density-dependent electron scattering rate in photoexcited GaAs in a large range of carrier densities. The electron scattering time decreases by as much as a factor of 4, from 320 to 60 fs, as the electron density...

Unit-time scheduling problems with time dependent resources

NARCIS (Netherlands)

Tautenhahn, T.; Woeginger, G.

1997-01-01

We investigate the computational complexity of scheduling problems, where the operations consume certain amounts of renewable resources which are available in time-dependent quantities. In particular, we consider unit-time open shop problems and unit-time scheduling problems with identical parallel

Effect of Electronic Monitoring on Social Welfare Dependence

DEFF Research Database (Denmark)

Andersen, Lars Højsgaard; Andersen, Signe Hald

2014-01-01

Research Summary We studied the effect on unemployment social welfare dependence of serving a sentence under elec-tronic monitoring rather than in prison, using Danish registry data and two policy shifts that extended the use of electronic monitoring in Denmark. We found electronic monitoring...... to experiences from other contexts. The experiences from Denmark are clear: Electronic monitoring is less harmful than imprisonment to the life course out-comes of offenders. Since electronic monitoring could also very well be less costly for the corrections administrations than imprisonment, efforts to extend...... the use of electronic monitoring in the United States could be accelerated....

Shape-dependent electronic properties of blue phosphorene nano-flakes

Energy Technology Data Exchange (ETDEWEB)

Bhatia, Pradeep; Swaroop, Ram; Kumar, Ashok, E-mail: ashok@cup.ac.in [Center for Physical Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda-151001 (India)

2016-05-06

In recent year’s considerable attention has been given to the first principles method for modifying and controlling electronic properties of nano-materials. We performed DFT-based calculations on the electronic properties of zigzag-edged nano-flakes of blue phosphorene with three possible shapes namely rectangular, triangular and hexagonal. We observed that HOMO-LUMO gap of zigzag phosphorene nano-flakes with different shapes is ∼2.9 eV with H-passivations and ∼0.7 – 1.2 eV in pristine cases. Electronic properties of blue phosphorene nano-flakes show the strong dependence on their shape. We observed that distributions of molecular orbitals were strongly affected by the different shapes. Zigzag edged considered nanostructures are non-magnetic and semiconducting in nature. The shape dependent electronic properties may find applications in tunable nano-electronics.

USE OF ELECTRONIC EDUCATIONAL RESOURCES WHEN TRAINING IN WORK WITH SPREADSHEETS

Directory of Open Access Journals (Sweden)

Х А Гербеков

2017-12-01

Full Text Available Today the tools for maintaining training courses based on opportunities of information and communication technologies are developed. Practically in all directions of preparation and on all subject matters electronic textbook and self-instruction manuals are created. Nevertheless the industry of computer educational and methodical materials actively develops and gets more and more areas of development and introduction. In this regard more and more urgent is a problem of development of the electronic educational resources adequate to modern educational requirements. Creation and the organization of training courses with use of electronic educational resources in particular on the basis of Internet technologies remains a difficult methodical task.In article the questions connected with development of electronic educational resources for use when studying the substantial line “Information technologies” of a school course of informatics in particular for studying of spreadsheets are considered. Also the analysis of maintenance of a school course and the unified state examination from the point of view of representation of task in him corresponding to the substantial line of studying “Information technologies” on mastering technology of information processing in spreadsheets and the methods of visualization given by means of charts and schedules is carried out.

Density-dependent electron scattering in photoexcited GaAs in strongly diffusive regime

DEFF Research Database (Denmark)

Mics, Zoltán; D’Angio, Andrea; Jensen, Søren A.

2013-01-01

In a series of systematic optical pump–terahertz probe experiments, we study the density-dependent electron scattering rate in photoexcited GaAs in the regime of strong carrier diffusion. The terahertz frequency-resolved transient sheet conductivity spectra are perfectly described by the Drude...... model, directly yielding the electron scattering rates. A diffusion model is applied to determine the spatial extent of the photoexcited electron-hole gas at each moment after photoexcitation, yielding the time-dependent electron density, and hence the density-dependent electron scattering time. We find...

Natural resource dependence, human capital accumulation, and economic growth: A combined explanation for the resource curse and the resource blessing

International Nuclear Information System (INIS)

Shao, Shuai; Yang, Lili

2014-01-01

In existing studies, no consensus has been reached on the relationship between natural resource dependence and human capital accumulation. To narrow the divergence, this paper carries out a normative research to explain the co-existence of the phenomena of the resource curse and the resource blessing based on an organic combination of conceptual and mathematical models. It first establishes a conceptual model to analyse the potential effects of the government's policy preference and natural resource development activities on human capital accumulation and economic growth. Furthermore, it develops an endogenous growth model to normatively illuminate the effects in the conceptual model and to explore the condition for the occurrence of the resource curse. The conceptual model analysis indicates that the rate of return on education investment and government behaviours play the crucial role in promoting the formation of the economic virtuous circle at the micro-level and macro-level, respectively, while resource development activities exert dual impacts on the circle. The main mechanisms in the conceptual model can be validated in the mathematical model. The rise in the subjective discount rate, the elasticity of intertemporal substitution, and resource goods price are adverse to the economic virtuous circle, while high-quality education and the institutional environment giving priority to manufacturing can become the necessary condition and sufficient condition for forming the circle, respectively. The allocation efficiency of production factors plays a decisive role in whether the blessing occurs, whereas sufficient human capital is an essential guarantee for evading the curse. - Highlights: • We conduct normative research combining a conceptual model and a mathematical model. • We discuss the potential impact of resource dependence on human capital and growth. • We explain the co-existence of the resource blessing and resource curse phenomena. �

Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

Directory of Open Access Journals (Sweden)

Sunil Tyagi

2014-02-01

Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

Intraspecific density dependence and a guild of consumers coexisting on one resource.

Science.gov (United States)

McPeek, Mark A

2012-12-01

The importance of negative intraspecific density dependence to promoting species coexistence in a community is well accepted. However, such mechanisms are typically omitted from more explicit models of community dynamics. Here I analyze a variation of the Rosenzweig-MacArthur consumer-resource model that includes negative intraspecific density dependence for consumers to explore its effect on the coexistence of multiple consumers feeding on a single resource. This analysis demonstrates that a guild of multiple consumers can easily coexist on a single resource if each limits its own abundance to some degree, and stronger intraspecific density dependence permits a wider variety of consumers to coexist. The mechanism permitting multiple consumers to coexist works in a fashion similar to apparent competition or to each consumer having its own specialized predator. These results argue for a more explicit emphasis on how negative intraspecific density dependence is generated and how these mechanisms combine with species interactions to shape overall community structure.

Page 170 Use of Electronic Resources by Undergraduates in Two ...

African Journals Online (AJOL)

undergraduate students use electronic resources such as NUC virtual library, HINARI, ... web pages articles from magazines, encyclopedias, pamphlets and other .... of Nigerian university libraries have Internet connectivity, some of the system.

Temperature Dependence of the Spin-Hall Conductivity of a Two-Dimensional Impure Rashba Electron Gas in the Presence of Electron-Phonon and Electron-Electron Interactions

Science.gov (United States)

Yavari, H.; Mokhtari, M.; Bayervand, A.

2015-03-01

Based on Kubo's linear response formalism, temperature dependence of the spin-Hall conductivity of a two-dimensional impure (magnetic and nonmagnetic impurities) Rashba electron gas in the presence of electron-electron and electron-phonon interactions is analyzed theoretically. We will show that the temperature dependence of the spin-Hall conductivity is determined by the relaxation rates due to these interactions. At low temperature, the elastic lifetimes ( and are determined by magnetic and nonmagnetic impurity concentrations which are independent of the temperature, while the inelastic lifetimes ( and related to the electron-electron and electron-phonon interactions, decrease when the temperature increases. We will also show that since the spin-Hall conductivity is sensitive to temperature, we can distinguish the intrinsic and extrinsic contributions.

Spin-dependent electron many-body effects in GaAs

Science.gov (United States)

Nemec, P.; Kerachian, Y.; van Driel, H. M.; Smirl, Arthur L.

2005-12-01

Time- and polarization-resolved differential transmission measurements employing same and oppositely circularly polarized 150fs optical pulses are used to investigate spin characteristics of conduction band electrons in bulk GaAs at 295K . Electrons and holes with densities in the 2×1016cm-3-1018cm-3 range are generated and probed with pulses whose center wavelength is between 865 and 775nm . The transmissivity results can be explained in terms of the spin sensitivity of both phase-space filling and many-body effects (band-gap renormalization and screening of the Coulomb enhancement factor). For excitation and probing at 865nm , just above the band-gap edge, the transmissivity changes mainly reflect spin-dependent phase-space filling which is dominated by the electron Fermi factors. However, for 775nm probing, the influence of many-body effects on the induced transmission change are comparable with those from reduced phase space filling, exposing the spin dependence of the many-body effects. If one does not take account of these spin-dependent effects one can misinterpret both the magnitude and time evolution of the electron spin polarization. For suitable measurements we find that the electron spin relaxation time is 130ps .

Model of e-learning with electronic educational resources of new generation

Directory of Open Access Journals (Sweden)

A. V. Loban

2017-01-01

Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

A survey of the use of electronic scientific information resources among medical and dental students

Directory of Open Access Journals (Sweden)

Aarnio Matti

2006-05-01

Full Text Available Abstract Background To evaluate medical and dental students' utilization of electronic information resources. Methods A web survey sent to 837 students (49.9% responded. Results Twenty-four per cent of medical students and ninteen per cent of dental students searched MEDLINE 2+ times/month for study purposes, and thiry-two per cent and twenty-four per cent respectively for research. Full-text articles were used 2+ times/month by thirty-three per cent of medical and ten per cent of dental students. Twelve per cent of respondents never utilized either MEDLINE or full-text articles. In multivariate models, the information-searching skills among students were significantly associated with use of MEDLINE and full-text articles. Conclusion Use of electronic resources differs among students. Forty percent were non-users of full-text articles. Information-searching skills are correlated with the use of electronic resources, but the level of basic PC skills plays not a major role in using these resources. The student data shows that adequate training in information-searching skills will increase the use of electronic information resources.

Access to electronic information resources by students of federal ...

African Journals Online (AJOL)

The paper discusses access to electronic information resources by students of Federal Colleges of Education in Eha-Amufu and Umunze. Descriptive survey design was used to investigate sample of 526 students. Sampling technique used was a Multi sampling technique. Data for the study were generated using ...

Adoption and use of electronic information resources by medical ...

African Journals Online (AJOL)

This study investigated the adoption and use of electronic information resources by medical science students of the University of Benin. The descriptive survey research design was adopted for the study and 390 students provided the data. Data collected were analysed with descriptive Statistics(Simple percentage and ...

Home and parenting resources available to siblings depending on their birth intention status.

Science.gov (United States)

Barber, Jennifer S; East, Patricia L

2009-01-01

This study examines the differential availability of family and parenting resources to children depending on their birth planning status. The National Longitudinal Survey of Youth data were analyzed, 3,134 mothers and their 5,890 children (M = 7.1 years, range = 1 month-14.8 years), of whom 63% were intended at conception, 27% were mistimed, and 10% were unwanted. Fixed-effects models show that unwanted and mistimed children had fewer resources than intended siblings. Parents' emotional resources to older children decreased after the birth of a mistimed sibling. Findings suggest that cognitive and emotional resources are differentially available to children within a family depending on intention status and that unintended births lead to decreased parental resources for older children in the household.

Comparing Public and Private Institutions That Have and Have Not Implemented Enterprise Resource Planning (ERP) Systems: A Resource Dependence Perspective

Science.gov (United States)

Sendhil, Geetha R.

2012-01-01

The purpose of this national study was to utilize quantitative methods to examine institutional characteristics, financial resource variables, personnel variables, and customer variables of public and private institutions that have and have not implemented enterprise resource planning (ERP) systems, from a resource dependence perspective.…

Size-dependent electronic properties of metal nanostructures

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Size-dependent electronic properties of metal nanostructures. G.U. Kulkarni. Chemistry and Physics of Materials Unit. Jawaharlal Nehru Centre for Advanced Scientific Research. Bangalore, India. kulkarni@jncasr.ac.in.

Where Do Electronic Books Fit in the College Research Arsenal of Resources?

Science.gov (United States)

Barbier, Patricia

2007-01-01

Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

Nanoporous metal film: An energy-dependent transmission device for electron waves

International Nuclear Information System (INIS)

Grech, S.; Degiovanni, A.; Lapena, L.; Morin, R.

2011-01-01

We measure electron transmission through free-standing ultrathin nanoporous gold films, using the coherent electron beam emitted by sharp field emission tips in a low energy electron projection microscope setup. Transmission coefficient versus electron wavelength plots show periodic oscillations between 75 and 850 eV. These oscillations result from the energy dependence of interference between paths through the gold and paths through the nanometer-sized pores of the film. We reveal that these films constitute high transmittance quantum devices acting on electron waves through a wavelength-dependent complex transmittance defined by the porosity and the thickness of the film.

Simulation of Probe Position-Dependent Electron Energy-Loss Fine Structure

Energy Technology Data Exchange (ETDEWEB)

Oxley, M. P.; Kapetanakis, M. D.; Prange, Micah P.; Varela, M.; Pennycook, Stephen J.; Pantelides, Sokrates T.

2014-03-31

We present a theoretical framework for calculating probe-position-dependent electron energy-loss near-edge structure for the scanning transmission electron microscope by combining density functional theory with dynamical scattering theory. We show how simpler approaches to calculating near-edge structure fail to include the fundamental physics needed to understand the evolution of near-edge structure as a function of probe position and investigate the dependence of near-edge structure on probe size. It is within this framework that density functional theory should be presented, in order to ensure that variations of near-edge structure are truly due to local electronic structure and how much from the diffraction and focusing of the electron beam.

Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

Science.gov (United States)

Hulseberg, Anna; Monson, Sarah

2009-01-01

Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

REVIEW OF MOODLE PLUGINS FOR DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES FROM LANGUAGE DISCIPLINES

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2015-09-01

Full Text Available Today the problem of designing multimedia electronic educational resources from language disciplines in Moodle is very important. This system has a lot of different, powerful resources, plugins to facilitate the learning of students with language disciplines. This article presents an overview and comparative analysis of the five Moodle plugins for designing multimedia electronic educational resources from language disciplines. There have been considered their key features and functionality in order to choose the best for studying language disciplines in the Moodle. Plugins are compared by a group of experts according to the criteria: efficiency, functionality and easy use. For a comparative analysis of the plugins it is used the analytic hierarchy process.

Bremsstrahlung of La and its dependence on electron energy

International Nuclear Information System (INIS)

Riehle, F.

1977-01-01

Measurements of La-bremsstrahlung isocromates with high resolution for quantum energies between 135 eV and 1867 eV are presented and discussed. In the whole energy range investigated, the isocromate structure, identified with the 4f band of La, is placed 5,45 +- 10,1 eV above the Fermi level. This is in contradiction with a calculation of Gloetzel, which predicts the 4f band maximum about 3eV above the Fermi level. This discrepancy is explained in the present work by the fact that the La electronic density of states depends on the occupation number of the states. The bremsstrahlung isocromate has to be considered as a direct copy of the La ion density of states, consisting of the La-atom and the additional primary electron. Resonance like intensity modulations of the x-ray radiation, resulting from transitions of the primary electron in f-like final states, are observed in an analysis of the La-bremsstrahlung isochromate energy dependence. For transitions of the primary electron in d-like final states, no resonances have been found. The energy dependence of the scattering probability in f-like final states can be explained by a model which assumes the final state as composed by a continuum state and a discrete state. (orig.) [de

Overpotential-induced lability of the electronic overlap factor in long-range electrochemical electron transfer: charge and distance dependence

DEFF Research Database (Denmark)

Kornyshev, A. A.; Kuznetsov, A. M.; Nielsen, Jens Ulrik

2000-01-01

Long-distance electrochemical electron transfer exhibits approximately exponential dependence on the electron transfer distance. On the basis of a jellium model of the metal surface we show that the slope of the logarithm of the current vs. the transfer distance also depends strongly...

Modern ICT Tools: Online Electronic Resources Sharing Using Web ...

African Journals Online (AJOL)

Modern ICT Tools: Online Electronic Resources Sharing Using Web 2.0 and Its Implications For Library And Information Practice In Nigeria. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more ...

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2017-10-01

Full Text Available The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system should be assessed. Developed a model for the development of the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system, which is based on the main scientific approaches, used in adult education, and consists of five blocks: target, informative, technological, diagnostic and effective.

Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

Science.gov (United States)

Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

2014-01-01

This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

The dependence of the electronic coupling on energy gap and bridge conformation - Towards prediction of the distance dependence of electron transfer reactions

International Nuclear Information System (INIS)

Eng, Mattias P.; Albinsson, Bo

2009-01-01

The attenuation factor, β, for the distance dependence of electron exchange reactions is a sensitive function of the donor-bridge energy gap and bridge conformation. In this work the electronic coupling for electron and triplet excitation energy transfer has been investigated for five commonly used repeating bridge structures. The investigated bridge structures are OF (oligo fluorene), OP (oligo phenylene), OPE (oligo p-phenyleneethynylene), OPV (oligo phenylenevinylene), and OTP (oligo thiophene). Firstly, the impact of the donor-bridge energy gap was investigated by performing calculations with a variety of donors appended onto bridges that were kept in a planar conformation. This resulted in, to our knowledge, the first presented sets of bridge specific parameters to be inserted into the commonly used McConnell model. Secondly, since at experimental conditions large conformational flexibility is expected, a previously developed model that takes conformational disorder of the bridge into account has been applied to the investigated systems [M.P. Eng, T. Ljungdahl, J. Martensson, B. Albinsson, J. Phys. Chem. B 110 (2006) 6483]. This model is based on Boltzmann averaging and has been shown to describe the temperature dependence of the attenuation factor through OPE-bridges. Together, the parameters describing the donor-bridge energy gap dependence, for planar bridge structures, and the Boltzmann averaging procedure, describing the impact of rotational disorder, have the potential to a priori predict attenuation factors for electron and excitation energy transfer reactions through bridged donor-acceptor systems

Dependency on floral resources determines the animals' responses to floral scents

OpenAIRE

Junker, Robert R; Blüthgen, Nico

2010-01-01

Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination—the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including m...

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

Analysis of Tourism Resource Dependency on Collaboration among Local Governments in the Multi-Regional Tourism Development

Directory of Open Access Journals (Sweden)

Ha Dong-Won

2014-01-01

Full Text Available The purpose of this study was to derive the multidimensional attributes of resource dependency of local governments in multi-regional tourism development. The questionnaire was designed based on resource dependence theory and related literature, and five factors of resource dependency were derived by analysis of the questionnaire for the civil servants who participated in the Jirisan area tourism development project which is a representative multi-regional tourism development project of Korea. The measured values of the derived possession, importance, discretion, alternative, and connection were found in various ways according to the project characteristics such as project scale and visitors in the Jirisan area tourism development project. This shows that a variety of variables have an effect on resource dependency.

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

Bootstrapping as a Resource Dependence Management Strategy and its Association with Startup Growth

OpenAIRE

T. VANACKER; S. MANIGART; M. MEULEMAN; L. SELS

2011-01-01

This paper studies the association between bootstrapping and startup growth. Bootstrapping reduces a startup’s dependence on financial investors, but may create new dependencies. Drawing upon resource dependence theory, we hypothesize that when bootstrapping does not create new strong dependencies it will benefit startup growth, especially when dependence from financial investors is high. However, when bootstrapping creates new strong dependencies it will constrain growth, especially when dep...

Electron transfer in organic glass. Distance and energy dependence

International Nuclear Information System (INIS)

Krongauz, V.V.

1992-01-01

The authors have investigated the distance and energy dependence of electron transfer in rigid organic glasses containing randomly dispersed electron donor and electron acceptor molecules. Pulsed radiolysis by an electron beam from a linear accelerator was used for ionization resulting in charge deposition on donor molecules. The disappearance kinetics of donor radical anions due to electron transfer to acceptor was monitored spectroscopically by the change in optical density at the wavelength corresponding to that of donor radical anion absorbance. It was found that the rate of the electron transfer observed experimentally was higher than that computed using the Marcus-Levich theory assuming that the electron-transfer activation barrier is equal to the binding energy of electron on the donor molecule. This discrepancy between the experimental and computed results suggests that the open-quotes inertclose quotes media in which electron-transfer reaction takes place may be participating in the process, resulting in experimentally observed higher electron-transfer rates. 32 refs., 3 figs., 2 tabs

Electronic Resource Management System. Vernetzung von Lizenzinformationen

Directory of Open Access Journals (Sweden)

Michaela Selbach

2014-12-01

Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

Hysteresis loops of spin-dependent electronic current in a paramagnetic resonant tunnelling diode

International Nuclear Information System (INIS)

Wójcik, P; Spisak, B J; Wołoszyn, M; Adamowski, J

2012-01-01

Nonlinear properties of the spin-dependent electronic transport through a semiconductor resonant tunnelling diode with a paramagnetic quantum well are considered. The spin-dependent Wigner–Poisson model of the electronic transport and the two-current Mott’s formula for the independent spin channels are applied to determine the current–voltage curves of the nanodevice. Two types of the electronic current hysteresis loops are found in the current–voltage characteristics for both the spin components of the electronic current. The physical interpretation of these two types of the electronic current hysteresis loops is given based on the analysis of the spin-dependent electron densities and the potential energy profiles. The differences between the current–voltage characteristics for both the spin components of the electronic current allow us to explore the changes of the spin polarization of the current for different electric fields and determine the influence of the electronic current hysteresis on the spin polarization of the current flowing through the paramagnetic resonant tunnelling diode. (paper)

The Electron Microscopy Outreach Program: A Web-based resource for research and education.

Science.gov (United States)

Sosinsky, G E; Baker, T S; Hand, G; Ellisman, M H

1999-01-01

We have developed a centralized World Wide Web (WWW)-based environment that serves as a resource of software tools and expertise for biological electron microscopy. A major focus is molecular electron microscopy, but the site also includes information and links on structural biology at all levels of resolution. This site serves to help integrate or link structural biology techniques in accordance with user needs. The WWW site, called the Electron Microscopy (EM) Outreach Program (URL: http://emoutreach.sdsc.edu), provides scientists with computational and educational tools for their research and edification. In particular, we have set up a centralized resource containing course notes, references, and links to image analysis and three-dimensional reconstruction software for investigators wanting to learn about EM techniques either within or outside of their fields of expertise. Copyright 1999 Academic Press.

Technical Communicator: A New Model for the Electronic Resources Librarian?

Science.gov (United States)

Hulseberg, Anna

2016-01-01

This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

Dependability in electronic systems mitigation of hardware failures, soft errors, and electro-magnetic disturbances

CERN Document Server

Kanekawa, Nobuyasu; Suga, Takashi; Uematsu, Yutaka

2011-01-01

Dependability in Electronic Systems presents practical applications for dependable electronic systems, such as train control, automotive control systems and network servers/routers. Readers will find an overview of dependability, enabling them to select the best choice for maximum results.

Examining the ‘’Natural Resource Curse’’ and the Impact of Various Forms of Capital in Small Tourism and Natural Resource-Dependent Economies

Directory of Open Access Journals (Sweden)

Petar Kurecic

2017-02-01

Full Text Available The problem of the relevance of human and natural capital, as well as the potential adverse effect of natural capital on economic growth, has gained increased attention in development economics. The aim of this paper is to assess, theoretically and empirically, the relevance of several forms of capital on economic growth in certain small economies that are dependent upon tourism or natural resources. The empirical framework is based on Impulse Response Functions obtained from Vector Autoregressive models in which we focus on the model where economic growth is the dependent variable for ten small economies that are dependent upon either tourism or natural resources. We find that there is evidence of the “natural resource curse”, especially in the economies that have a strong dependence on resources that are easily substitutable and whose prices constantly fluctuate. We further find that in the majority of observed cases, the type of capital these small economies are most dependent on for their economic growth causes negative impulses in the majority of the observed periods. Therefore, the main policy recommendation should be to assure that even these small economies should strive towards further diversification and avoid dependence on only one segment of their economy.

MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

Directory of Open Access Journals (Sweden)

Anatoliy V. Loban

2016-01-01

Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

Deriving the coronal hole electron temperature: electron density dependent ionization / recombination considerations

International Nuclear Information System (INIS)

Doyle, John Gerard; Perez-Suarez, David; Singh, Avninda; Chapman, Steven; Bryans, Paul; Summers, Hugh; Savin, Daniel Wolf

2010-01-01

Comparison of appropriate theoretically derived line ratios with observational data can yield estimates of a plasma's physical parameters, such as electron density or temperature. The usual practice in the calculation of the line ratio is the assumption of excitation by electrons/protons followed by radiative decay. Furthermore, it is normal to use the so-called coronal approximation, i.e. one only considers ionization and recombination to and from the ground-state. A more accurate treatment is to include ionization/recombination to and from metastable levels. Here, we apply this to two lines from adjacent ionization stages, Mg IX 368 A and Mg X 625 A, which has been shown to be a very useful temperature diagnostic. At densities typical of coronal hole conditions, the difference between the electron temperature derived assuming the zero density limit compared with the electron density dependent ionization/recombination is small. This, however, is not the case for flares where the electron density is orders of magnitude larger. The derived temperature for the coronal hole at solar maximum is around 1.04 MK compared to just below 0.82 MK at solar minimum.

Board leadership structure and firm performance: An examination of resource dependence role

Directory of Open Access Journals (Sweden)

Afzalur Rashid

2011-01-01

Full Text Available This study examines if the CEO duality influence the firm economic performance in Bangladesh and the moderating effects of board composition in the form of outside independent directors. While doing so, it examines the relationship between CEO duality and firm performance during the pre appointment of outside independent directors and post appointment of outside independent directors (the role of other corporate governance mechanism as moderating variable. The finding is that there is there is a negative (non-significant relationship between CEO duality and firm performance before appointment of outside independent directors in the board. However, independent leadership structure and firm performance is found to be positively related following the acquisition of resource (outside independent directors in the board supporting the ’resource dependence theory’. The findings of this study partially support the ’agency theory’ and ’resource dependence theory’ but do not support the stewardship theory. This study contributes to the literature on CEO duality in the context of less a developed country.

Industrial symbiosis as a countermeasure for resource dependent city: a case study of Guiyang, China

DEFF Research Database (Denmark)

Li, Hong; Dong, Liang; Ren, Jingzheng

2015-01-01

Solutions towards sustainable cities are of vital importance for China's stakeholders due to the rapid urbanizations, serious resources depletion and environmental contaminations in China. China as the second largest economy is suffering from the dilemma of rapid industrialization and urbanization......, and sustainable development. One of the most severe problems affecting China's sustainable urban development is the resource dependent city, in which resource mining and process industries dominate the local economy. With the depletion of natural resources and the degradation of environment, the concept...... of sustainability and economy transition solutions become more and more important. Under this condition, this study aims to conduct a comprehensive review on the major projects for a more sustainable future in China's national resource dependent cities and propose a countermeasure for the sustainability transition...

Impact of supplier-specific investments in inter-organisational information systems on strategic electronic coordination: the moderation effect of buyer dependence

Directory of Open Access Journals (Sweden)

Teryokhin Sergei

2018-03-01

Full Text Available This paper examines the factors which influence sharing of the strategic information (in other words, electronic coordination in a buyer–supplier dyad. The antecedents of this coordination are examined rather well in the transaction cost economics (TCE theory and resource-dependency theory (RDT, while the supply chain management perspective is contemplated. The mentioned frameworks are used in the analysis. However, the research focus is narrowed down to the exploration of the antecedents of information exchange conducted via inter-organisational information systems (IOS. The empirical analysis is based on 198 observations of Norwegian companies operating in different types of industries. A regression model is used to test the hypotheses about the antecedents of strategic electronic coordination. The research results indicate that the direct effect of the supplier-specific investments in the IOS on the exchange of strategic information in the buyer–supplier dyad is not statistically significant. The supplier-specific investment in the IOS becomes positively associated with the strategic information exchange in the buyer–supplier dyad only when the buyer is dependent on the supplier. The buyer dependency creates a high motivation for the company to exchange the strategic information with the supplier who is more powerful in the dyad. This research concludes that the companies making substantial investments in the IOS for electronic coordination purposes may not reach their goals if relation-specific factors, such as buyer dependency, are not comprehensively considered.

On conservation of renewable resources with stock-dependent return and non-concave production

International Nuclear Information System (INIS)

Olson, Lars J.; Roy, Santanu

1994-05-01

An analysis is presented of the intertemporal choice foundations underlying the conservation or extinction of renewable resources when the resource production function is non-concave and the immediate return function depends on both current consumption and the size of the resource stock. This case may exhibit nonlinear dynamics and extinction is possible from high stocks even if conservation occurs from lower stocks. The paper focusses on the influence of preferences and the production function on the efficiency of: global conservation, the existence of a safe standard of conservation, or extinction. We show that conservation is efficient under weaker conditions than the 'δ-productivity' requirements derived in models where return function is not stock-dependent. The marginal rate of substitution between investment and the stock plays an important role in addition to the discount factor and the marginal productivity of the resource. Extinction need not be optimal even if the intrinsic growth rate of the resource is less than the external rate of return. Our analysis demonstrates the potential role of taxes, subsidies, demand forces, and harvest costs in determining the efficiency of conservation or extinction. 3 figs., 1 appendix, 24 refs

On conservation of renewable resources with stock-dependent return and non-concave production

Energy Technology Data Exchange (ETDEWEB)

Olson, Lars J. [Department of Agricultural and Resource Economics, University of Maryland, College Park, MD (United States); Roy, Santanu [Econometric Institute, Erasmus University, Rotterdam (Netherlands)

1994-05-01

An analysis is presented of the intertemporal choice foundations underlying the conservation or extinction of renewable resources when the resource production function is non-concave and the immediate return function depends on both current consumption and the size of the resource stock. This case may exhibit nonlinear dynamics and extinction is possible from high stocks even if conservation occurs from lower stocks. The paper focusses on the influence of preferences and the production function on the efficiency of: global conservation, the existence of a safe standard of conservation, or extinction. We show that conservation is efficient under weaker conditions than the `{delta}-productivity` requirements derived in models where return function is not stock-dependent. The marginal rate of substitution between investment and the stock plays an important role in addition to the discount factor and the marginal productivity of the resource. Extinction need not be optimal even if the intrinsic growth rate of the resource is less than the external rate of return. Our analysis demonstrates the potential role of taxes, subsidies, demand forces, and harvest costs in determining the efficiency of conservation or extinction. 3 figs., 1 appendix, 24 refs.

Temperature dependence of electron concentration in cadmium arsenide

NARCIS (Netherlands)

Gelten, M.J.; Blom, F.A.P.

1979-01-01

From measurements of the temperature dependence of the electron concentration in Cd 3 As 2 , we found values for the conduction-band parameters that are in good agreement with those recently reported by Aubin, Caron, and Jay-Gerin. However, in contrast with these authors we found no small overlap,

Impact-parameter-dependent electronic stopping of swift ions

NARCIS (Netherlands)

Schinner, A.; Sigmund, P.

2010-01-01

A computational scheme has been developed to estimate the mean electronic energy loss of an incident swift ion on an atomic target as a function of the impact parameter between the moving nuclei. The theoretical basis is binary stopping theory. In order to extract impact-parameter dependencies it

Temperature dependence of electron mean free path in molybdenum from ultrasonic measurements

Energy Technology Data Exchange (ETDEWEB)

Almond, D P; Detwiler, D A; Rayne, J A [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

1975-09-08

The temperature dependence of the electronic mean free path in molybdenum has been obtained from ultrasonic attenuation measurements.For temperature up to 30 K a T/sup -2/ law is followed suggesting the importance of electron-electron scattering in the attenuation mechanism.

Study of the SEY dependence on the electron beams dose and energy

International Nuclear Information System (INIS)

Commisso, M.

2011-01-01

During operation, the internal walls of modern particle accelerators are subjected to synchrotron radiation irradiation and/or electron bombardment. Such phenomena do affect surface properties such as the secondary electron yield, (SEY). A low SEY is a key parameter to control and overcome any detrimental effect on the accelerator performance eventually induced by the build-up of an Electron Cloud (E C). In laboratory experiments SEY reduction (called scrubbing) has been studied as a function of dose but the actual kinetic energy dependence has never been considered as an important parameter. For this reason and given the peculiar behavior observed for low-energy electrons, we decided to study this dependence accurately. Here we report results of SEY measurements performed bombarding Cu samples obtained from the Large Hadron Collider (Lhc) with different doses of electron beam with energy in the range 10-500 eV. Our results demonstrate that the potentiality of an electron beam to reduce the SEY does not only depend on its dose, but also on its energy. Furthermore, since E C build-up was predicted and observed also the DAΦNE ring, we report some preliminary measurements on the conditioning of Al samples. An overview of future experiments which we will perform in LNF is then given.

Field dependence of the electron spin relaxation in quantum dots.

Science.gov (United States)

Calero, Carlos; Chudnovsky, E M; Garanin, D A

2005-10-14

The interaction of the electron spin with local elastic twists due to transverse phonons is studied. The universal dependence of the spin-relaxation rate on the strength and direction of the magnetic field is obtained in terms of the electron gyromagnetic tensor and macroscopic elastic constants of the solid. The theory contains no unknown parameters and it can be easily tested in experiment. At high magnetic field it provides a parameter-free lower bound on the electron spin relaxation in quantum dots.

Dependency on floral resources determines the animals' responses to floral scents.

Science.gov (United States)

Junker, Robert R; Blüthgen, Nico

2010-08-01

Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination - the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including mechanisms to bypass or tolerate floral defences such as morphological barriers and repellent / deterrent secondary metabolites. Facultative flower visitors, in contrast, are supposed to lack these adaptations and are often prevented to consume floral resources by defence mechanisms. In cases where obligate flower visitors are mutualists and facultative ones are antagonists, this dichotomy provides a solution for the plants' dilemma to attract pollinators and simultaneously repel exploiters. In a meta-analysis, we recently supported this hypothesis: obligate flower visitors are attracted to floral scents, while facultative ones are repelled. Here, we add empirical evidence to these results: bumblebees and ants, obligate and facultative flower visitors, respectively, responded as predicted by the results of the meta-analysis to synthetic floral scent compounds.

Experimental study of parametric dependence of electron-scale turbulence in a spherical tokamak

Energy Technology Data Exchange (ETDEWEB)

Ren, Y.; Guttenfelder, W.; Kaye, S. M.; Mazzucato, E.; Bell, R. E.; Diallo, A.; LeBlanc, B. P. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Domier, C. W.; Lee, K. C. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

2012-05-15

Electron-scale turbulence is predicted to drive anomalous electron thermal transport. However, experimental study of its relation with transport is still in its early stage. On the National Spherical Tokamak Experiment (NSTX), electron-scale density fluctuations are studied with a novel tangential microwave scattering system with high radial resolution of {+-}2 cm. Here, we report a study of parametric dependence of electron-scale turbulence in NSTX H-mode plasmas. The dependence on density gradient is studied through the observation of a large density gradient variation in the core induced by an edge localized mode (ELM) event, where we found the first clear experimental evidence of density gradient stabilization of electron-gyro scale turbulence in a fusion plasma. This observation, coupled with linear gyro-kinetic calculations, leads to the identification of the observed instability as toroidal electron temperature gradient (ETG) modes. It is observed that longer wavelength ETG modes, k{sub Up-Tack }{rho}{sub s} Less-Than-Or-Equivalent-To 10 ({rho}{sub s} is the ion gyroradius at electron temperature and k{sub Up-Tack} is the wavenumber perpendicular to local equilibrium magnetic field), are most stabilized by density gradient, and the stabilization is accompanied by about a factor of two decrease in electron thermal diffusivity. Comparisons with nonlinear ETG gyrokinetic simulations show ETG turbulence may be able to explain the experimental electron heat flux observed before the ELM event. The collisionality dependence of electron-scale turbulence is also studied by systematically varying plasma current and toroidal field, so that electron gyroradius ({rho}{sub e}), electron beta ({beta}{sub e}), and safety factor (q{sub 95}) are kept approximately constant. More than a factor of two change in electron collisionality, {nu}{sub e}{sup *}, was achieved, and we found that the spectral power of electron-scale turbulence appears to increase as {nu}{sub e}{sup *} is

GUIDELINES FOR EVALUATION OF PSYCHOLOGICAL AND PEDAGOGICAL QUALITY CHARACTERISTICS OF ELECTRONIC EDUCATIONAL RESOURCES

Directory of Open Access Journals (Sweden)

Galina P. Lavrentieva

2014-05-01

Full Text Available The article highlights the causes of insufficient effective use of electronic learning resources and sets out the guidelines on ways to solve the aforementioned problems. The set of didactic, methodical, psychological, pedagogical, design and ergonomic quality requirements is considered for evaluation, selection and application of information and communication technologies in the educational process. The most appropriate mechanisms for the ICT introduction into the learning process are disclosed as it should meet the specific learning needs of the student and the objectives of the educational process. The guidance for psycho-educational assessment of quality of electronic educational resources is provided. It is argued that the effectiveness of the ICT use is to be improved by means of quality evaluation mechanisms involved into the educational process.

Sequence dependence of electron-induced DNA strand breakage revealed by DNA nanoarrays

DEFF Research Database (Denmark)

Keller, Adrian; Rackwitz, Jenny; Cauët, Emilie

2014-01-01

The electronic structure of DNA is determined by its nucleotide sequence, which is for instance exploited in molecular electronics. Here we demonstrate that also the DNA strand breakage induced by low-energy electrons (18 eV) depends on the nucleotide sequence. To determine the absolute cross sec...

Production and Resource Scheduling in Mass Customization with Dependent Setup Consideration

DEFF Research Database (Denmark)

Nielsen, Izabela Ewa; Bocewicz, G.; Do, Ngoc Anh Dung

2014-01-01

will contribute to the success of mass customization. This paper addresses the problem of production and resource scheduling for a production system with dependent setup and internal transportation such as AGVs in a mass customization environment. A constraint-programming-based methodology is developed to satisfy...

Ferromagnetism and temperature-dependent electronic structure in metallic films

International Nuclear Information System (INIS)

Herrmann, T.

1999-01-01

In this work the influence of the reduced translational symmetry on the magnetic properties of thin itinerant-electron films and surfaces is investigated within the strongly correlated Hubbard model. Firstly, the possibility of spontaneous ferromagnetism in the Hubbard model is discussed for the case of systems with full translational symmetry. Different approximation schemes for the solution of the many-body problem of the Hubbard model are introduced and discussed in detail. It is found that it is vital for a reasonable description of spontaneous ferromagnetism to be consistent with exact results concerning the general shape of the single-electron spectral density in the limit of strong Coulomb interaction between the electrons. The temperature dependence of the ferromagnetic solutions is discussed in detail by use of the magnetization curves as well as the spin-dependent quasi particle spectrum. For the investigation of thin films and surfaces the approximation schemes for the bulk system have to be generalized to deal with the reduced translational symmetry. The magnetic behavior of thin Hubbard films is investigated by use of the layer dependent magnetization as a function of temperature as well as the thickness of the film. The Curie-temperature is calculated as a function of the film thickness. Further, the magnetic stability at the surface is discussed in detail. Here it is found that for strong Coulomb interaction the magnetic stability at finite temperatures is reduced at the surface compared to the inner layers. This observation clearly contradicts the well-known Stoner picture of band magnetism and can be explained in terms of general arguments which are based on exact results in the limit of strong Coulomb interaction. The magnetic behavior of the Hubbard films can be analyzed in detail by inspecting the local quasi particle density of states as well as the wave vector dependent spectral density. The electronic structure is found to be strongly spin

Availability, Use and Constraints to Use of Electronic Information Resources by Postgraduates Students at the University of Ibadan

Directory of Open Access Journals (Sweden)

Dare Samuel Adeleke

2017-12-01

Full Text Available Availability, awareness and use of electronic resources provide access to authoritative, reliable, accurate and timely access to information. The use of electronic information resources (EIRs can enable innovation in teaching and increase timeliness in research of postgraduate students which will eventual result into encouragement of the expected research-led enquiry in this digital age. The study adopted a descriptive survey design. Samples of 300 of postgraduate students within seven out 13 Faculties were randomly selected. Data were collected using questionnaire designed to elicit response from respondents and data were analyzed using descriptive statistics methods percentages, mean, and standard deviation. Results indicated that internet was ranked most available and used in the university. Low level of usage of electronic resources, in particular, full texts data bases is linked to a number of constraints: Interrupted power supply was ranked highest among other factors as speed and capacity of computers, retrieval of records with high recall and low precision, retrieving records relevant to information need, lack of knowledge of search techniques to retrieve information effectively, non possession of requisite IT skills and problems accessing the internet. The study recommended that usage of electronic resources be made compulsory, intensifying awareness campaigns concerning the availability, training on use of electronic resources and the problem of power outage be addressed.

Contribution of inner shell electrons to position-dependent stopping powers of a crystal surface

International Nuclear Information System (INIS)

Narumi, Kazumasa; Fujii, Yoshikazu; Kishine, Keiji; Kurakake, Hiroshi; Kimura, Kenji; Mannami, Michi-hiko

1994-01-01

Position-dependent stopping powers of the (001) surface of SnTe single crystal for specularly reflected 15 - 200 keV H + ions are studied. The position dependence of the experimental stopping powers varies with the energy of ions. From the comparison with the theoretical stopping powers based on both the single ion-electron collision and the collective excitation of the valence electrons, it is concluded that the observed change in the position-dependent stopping powers with energy of H + is due to the variation of contribution of inner shell electrons to stopping. (author)

Electronic structure of free and doped actinides: N and Z dependences of energy levels and electronic structure parameters

International Nuclear Information System (INIS)

Kulagin, N.

2005-01-01

Theoretical study of electronic structure of antinide ions and its dependence on N and Z are presented in this paper. The main 5f N and excited 5f N n'l' N' configurations of actinides have been studied using Hartree-Fock-Pauli approximation. Results of calculations of radial integrals and the energy of X-ray lines for all 5f ions with electronic state AC +1 -AC +4 show approximate dependence on N and Z. A square of N and cubic of Z are ewalized for the primary electronic parameters of the actinides. Theoretical values of radial integrals for free actinides and for ions in a cluster AC +n :[L] k are compared, too

A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

Science.gov (United States)

Noh, Younghee

2010-01-01

This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

DCU 250 Arabic dependency bank: an LFG gold standard resource for the Arabic Penn treebank

OpenAIRE

Al-Raheb, Yafa; Akrout, Amine; van Genabith, Josef; Dichy, J.

2006-01-01

This paper describes the construction of a dependency bank gold standard for Arabic, DCU 250 Arabic Dependency Bank (DCU 250), based on the Arabic Penn Treebank Corpus (ATB) (Bies and Maamouri, 2003; Maamouri and Bies, 2004) within the theoretical framework of Lexical Functional Grammar (LFG). For parsing and automatically extracting grammatical and lexical resources from treebanks, it is necessary to evaluate against established gold standard resources. Gold standards for various languages h...

Journaling as reinforcement for the resourcefulness training intervention in mothers of technology-dependent children.

Science.gov (United States)

Toly, Valerie Boebel; Blanchette, Julia E; Musil, Carol M; Zauszniewski, Jaclene A

2016-11-01

Resourcefulness, a set of cognitive and behavioral skills used to attain, maintain, or regain health, is a factor related to depressive symptoms in mothers of children with chronic conditions and complex care needs who are dependent on medical technology such as mechanical ventilation or feeding tubes. The purpose of this secondary analysis of a randomized, controlled pilot intervention study was to determine the feasibility, acceptability and fidelity of daily journal writing as a method of reinforcement of resourcefulness training (RT) that teaches the use of social and personal resourcefulness skills. Participants returned their journals to the study office at the end of the four-week journaling exercise. Content analysis from exit interviews and journals supported the feasibility, acceptability and fidelity of daily journaling for reinforcement of RT in this population. Journal writing can be used by pediatric nurses to reinforce and promote resourcefulness skill use in parents of technology-dependent children. Copyright © 2016 Elsevier Inc. All rights reserved.

Modeling and Verification of Dependable Electronic Power System Architecture

Science.gov (United States)

Yuan, Ling; Fan, Ping; Zhang, Xiao-fang

The electronic power system can be viewed as a system composed of a set of concurrently interacting subsystems to generate, transmit, and distribute electric power. The complex interaction among sub-systems makes the design of electronic power system complicated. Furthermore, in order to guarantee the safe generation and distribution of electronic power, the fault tolerant mechanisms are incorporated in the system design to satisfy high reliability requirements. As a result, the incorporation makes the design of such system more complicated. We propose a dependable electronic power system architecture, which can provide a generic framework to guide the development of electronic power system to ease the development complexity. In order to provide common idioms and patterns to the system *designers, we formally model the electronic power system architecture by using the PVS formal language. Based on the PVS model of this system architecture, we formally verify the fault tolerant properties of the system architecture by using the PVS theorem prover, which can guarantee that the system architecture can satisfy high reliability requirements.

Molecular alignment dependent electron interference in attosecond ultraviolet photoionization

Directory of Open Access Journals (Sweden)

Kai-Jun Yuan

2015-01-01

Full Text Available We present molecular photoionization processes by intense attosecond ultraviolet laser pulses from numerical solutions of time-dependent Schrödinger equations. Simulations preformed on a single electron diatomic H2+ show minima in molecular photoelectron energy spectra resulting from two center interference effects which depend strongly on molecular alignment. We attribute such sensitivity to the spatial orientation asymmetry of the photoionization process from the two nuclei. A similar influence on photoelectron kinetic energies is also presented.

Molecular alignment dependent electron interference in attosecond ultraviolet photoionization

Science.gov (United States)

Yuan, Kai-Jun; Bandrauk, André D.

2015-01-01

We present molecular photoionization processes by intense attosecond ultraviolet laser pulses from numerical solutions of time-dependent Schrödinger equations. Simulations preformed on a single electron diatomic H2+ show minima in molecular photoelectron energy spectra resulting from two center interference effects which depend strongly on molecular alignment. We attribute such sensitivity to the spatial orientation asymmetry of the photoionization process from the two nuclei. A similar influence on photoelectron kinetic energies is also presented. PMID:26798785

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

OpenAIRE

Anton M. Avramchuk

2017-01-01

The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing ...

Size-dependent electronic properties of metal nanostructures

Indian Academy of Sciences (India)

Table of contents. Size-dependent electronic properties of metal nanostructures · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Nanocrystalline film at liquid-liquid interface · Slide 21 · Slide 22.

Temperature dependent transport of two dimensional electrons in the integral quantum Hall regime

International Nuclear Information System (INIS)

Wi, H.P.

1986-01-01

This thesis is concerned with the temperature dependent electronic transport properties of a two dimensional electron gas subject to background potential fluctuations and a perpendicular magnetic field. The author carried out an extensive temperature dependent study of the transport coefficients, in the region of an integral quantum plateau, in an In/sub x/Ga/sub 1-x/As/InP heterostructure for 4.2K 10 cm -2 meV -1 ) even at the middle between two Landau levels, which is unexpected from model calculations based on short ranged randomness. In addition, the different T dependent behavior of rho/sub xx/ between the states in the tails and those near the center of a Landau level, indicates the existence of different electron states in a Landau level. Additionally, the author reports T-dependent transport measurements in the transition region between two quantum plateaus in several different materials

Determining the level of awareness of the physicians in using the variety of electronic information resources and the effecting factors.

Science.gov (United States)

Papi, Ahmad; Ghazavi, Roghayeh; Moradi, Salimeh

2015-01-01

Understanding of the medical society's from the types of information resources for quick and easy access to information is an imperative task in medical researches and management of the treatment. The present study was aimed to determine the level of awareness of the physicians in using various electronic information resources and the factors affecting it. This study was a descriptive survey. The data collection tool was a researcher-made questionnaire. The study population included all the physicians and specialty physicians of the teaching hospitals affiliated to Isfahan University of Medical Sciences and numbered 350. The sample size based on Morgan's formula was set at 180. The content validity of the tool was confirmed by the library and information professionals and the reliability was 95%. Descriptive statistics were used including the SPSS software version 19. On reviewing the need of the physicians to obtain the information on several occasions, the need for information in conducting the researches was reported by the maximum number of physicians (91.9%) and the usage of information resources, especially the electronic resources, formed 65.4% as the highest rate with regard to meeting the information needs of the physicians. Among the electronic information databases, the maximum awareness was related to Medline with 86.5%. Among the various electronic information resources, the highest awareness (43.3%) was related to the E-journals. The highest usage (36%) was also from the same source. The studied physicians considered the most effective deterrent in the use of electronic information resources as being too busy and lack of time. Despite the importance of electronic information resources for the physician's community, there was no comprehensive knowledge of these resources. This can lead to less usage of these resources. Therefore, careful planning is necessary in the hospital libraries in order to introduce the facilities and full capabilities of the

Influence of soliton distributions on the spin-dependent electronic ...

Indian Academy of Sciences (India)

Based on Su–Schrieffer–Heeger (SSH) Hamiltonian and using a generalized Green's function formalism, wecalculate the spin-dependent currents, the electronic transmission and tunnelling magnetoresistance (TMR). We found that the presence of a uniform distribution of the soliton centres along the molecular chain ...

A consumer-resource approach to the density-dependent population dynamics of mutualism.

Science.gov (United States)

Holland, J Nathaniel; DeAngelis, Donald L

2010-05-01

Like predation and competition, mutualism is now recognized as a consumer-resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant-mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

A consumer-resource approach to the density-dependent population dynamics of mutualism

Science.gov (United States)

Holland, J. Nathaniel; DeAngelis, Donald L.

2010-01-01

Like predation and competition, mutualism is now recognized as a consumer resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant- mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

Science.gov (United States)

Downey, Kay

2012-01-01

Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

Polarization dependence in ELNES: Influence of probe convergence, collector aperture and electron beam incidence angle

International Nuclear Information System (INIS)

Le Bosse, J.C.; Epicier, T.; Jouffrey, B.

2006-01-01

The differential scattering cross section in electron energy loss near edge spectroscopy (ELNES) generally depends on the orientation of the Q wave vector transferred from the incident electron to an atomic core electron. In the case where the excited atom belongs to a threefold, fourfold or sixfold main rotation axis, the dipole cross section depends on the angle of Q with respect to this axis. In this paper, we restrict to this situation called dichroism. Furthermore, if we take into account the relativistic effects due to the high incident electron velocity, this dipole cross section also depends on the angle of Q with respect to the electron beam axis. It is due to these dependences that the shape of measured electron energy loss spectra varies with the electron beam incidence, the collector aperture, the incident beam convergence and the incident electron energy. The existence of a particular beam incidence angle for which the scattering cross section becomes independent of collection and beam convergence semi-angles is clearly underscored. Conversely, it is shown that EELS spectra do not depend on the beam incidence angle for a set of particular values of collection and convergence semi-angles. Particularly, in the case of a parallel incident beam, there is a collection semi-angle (often called magic angle) for which the cross section becomes independent of the beam orientation. This magic angle depends on the incident beam kinetic energy. If the incident electron velocity V is small compared with the light velocity c, this magic angle is about 3.975θ E (θ E is the scattering angle). It decreases to 0 when V approaches c. These results are illustrated in the case of the K boron edge in the boron nitride

Electric field dependence of the electron mobility in bulk wurtzite ZnO

Indian Academy of Sciences (India)

Electric field dependence of the electron mobility in bulk wurtzite ZnO. K ALFARAMAWI ... tion to ultraviolet light emitters, gas sensors, surface acoustic wave devices and ..... Dorkel J M and Leturcq P H 1981 Solid-State Electron. 24 8211.

End-of-life resource recovery from emerging electronic products

DEFF Research Database (Denmark)

Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

2016-01-01

Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

Electron mean free path from angle-dependent photoelectron spectroscopy of aerosol particles

Energy Technology Data Exchange (ETDEWEB)

Goldmann, Maximilian; Miguel-Sánchez, Javier; West, Adam H. C.; Yoder, Bruce L.; Signorell, Ruth, E-mail: rsignorell@ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich (Switzerland)

2015-06-14

We propose angle-resolved photoelectron spectroscopy of aerosol particles as an alternative way to determine the electron mean free path of low energy electrons in solid and liquid materials. The mean free path is obtained from fits of simulated photoemission images to experimental ones over a broad range of different aerosol particle sizes. The principal advantage of the aerosol approach is twofold. First, aerosol photoemission studies can be performed for many different materials, including liquids. Second, the size-dependent anisotropy of the photoelectrons can be exploited in addition to size-dependent changes in their kinetic energy. These finite size effects depend in different ways on the mean free path and thus provide more information on the mean free path than corresponding liquid jet, thin film, or bulk data. The present contribution is a proof of principle employing a simple model for the photoemission of electrons and preliminary experimental data for potassium chloride aerosol particles.

Use of electronic sales data to tailor nutrition education resources for an ethnically diverse population.

Science.gov (United States)

Eyles, H; Rodgers, A; Ni Mhurchu, C

2010-02-01

Nutrition education may be most effective when personally tailored. Individualised electronic supermarket sales data offer opportunities to tailor nutrition education using shopper's usual food purchases. The present study aimed to use individualised electronic supermarket sales data to tailor nutrition resources for an ethnically diverse population in a large supermarket intervention trial in New Zealand. Culturally appropriate nutrition education resources (i.e. messages and shopping lists) were developed with the target population (through two sets of focus groups) and ethnic researchers. A nutrient database of supermarket products was developed using retrospective sales data and linked to participant sales to allow tailoring by usual food purchases. Modified Heart Foundation Tick criteria were used to identify 'healthier' products in the database suitable for promotion in the resources. Rules were developed to create a monthly report listing the tailored and culturally targeted messages to be sent to each participant, and to produce automated, tailored shopping lists. Culturally targeted nutrition messages (n = 864) and shopping lists (n = 3 formats) were developed. The food and nutrient database (n = 3000 top-selling products) was created using 12 months of retrospective sales data, and comprised 60%'healthier' products. Three months of baseline sales data were used to determine usual food purchases. Tailored resources were successfully mailed to 123 Māori, 52 Pacific and 346 non-Māori non-Pacific participants over the 6-month trial intervention period. Electronic supermarket sales data can be used to tailor nutrition education resources for a large number of ethnically diverse supermarket shoppers.

Size-dependent single electron transfer and semi-metal-to-insulator transitions in molecular metal oxide electronics

Science.gov (United States)

Balliou, Angelika; Bouroushian, Mirtat; Douvas, Antonios M.; Skoulatakis, George; Kennou, Stella; Glezos, Nikos

2018-07-01

All-inorganic self-arranged molecular transition metal oxide hyperstructures based on polyoxometalate molecules (POMs) are fabricated and tested as electronically tunable components in emerging electronic devices. POM hyperstructures reveal great potential as charging nodes of tunable charging level for molecular memories and as enhancers of interfacial electron/hole injection for photovoltaic stacks. STM, UPS, UV–vis spectroscopy and AFM measurements show that this functionality stems from the films’ ability to structurally tune their HOMO–LUMO levels and electron localization length at room temperature. By adapting POM nanocluster size in solution, self-doping and current modulation of four orders of magnitude is monitored on a single nanocluster on SiO2 at voltages as low as 3 Volt. Structurally driven insulator-to-semi-metal transitions and size-dependent current regulation through single electron tunneling are demonstrated and examined with respect to the stereochemical and electronic structure of the molecular entities. This extends the value of self-assembly as a tool for correlation length and electronic properties tuning and demonstrate POM hyperstructures’ plausibility for on-chip molecular electronics operative at room temperature.

Size-dependent single electron transfer and semi-metal-to-insulator transitions in molecular metal oxide electronics.

Science.gov (United States)

Balliou, Angelika; Bouroushian, Mirtat; Douvas, Antonios M; Skoulatakis, George; Kennou, Stella; Glezos, Nikos

2018-07-06

All-inorganic self-arranged molecular transition metal oxide hyperstructures based on polyoxometalate molecules (POMs) are fabricated and tested as electronically tunable components in emerging electronic devices. POM hyperstructures reveal great potential as charging nodes of tunable charging level for molecular memories and as enhancers of interfacial electron/hole injection for photovoltaic stacks. STM, UPS, UV-vis spectroscopy and AFM measurements show that this functionality stems from the films' ability to structurally tune their HOMO-LUMO levels and electron localization length at room temperature. By adapting POM nanocluster size in solution, self-doping and current modulation of four orders of magnitude is monitored on a single nanocluster on SiO 2 at voltages as low as 3 Volt. Structurally driven insulator-to-semi-metal transitions and size-dependent current regulation through single electron tunneling are demonstrated and examined with respect to the stereochemical and electronic structure of the molecular entities. This extends the value of self-assembly as a tool for correlation length and electronic properties tuning and demonstrate POM hyperstructures' plausibility for on-chip molecular electronics operative at room temperature.

Intensity dependence of electron gas kinetics in a laser corona

Directory of Open Access Journals (Sweden)

Mašek Martin

2013-11-01

Full Text Available In various experimental situations relevant to the laser fusion, such as plasma near the light entrance holes of hohlraum in the indirect drive experiments or more recently in the shock ignition direct drive a relatively long underdense plasma of corona type is encountered, which is subject to an intense nanosecond laser beam. The plasma is only weakly collisional and thus in the electron phase space a complicated kinetic evolution is going on, which is taking the electron gas fairly far from the thermal equilibrium and contributes to its unstable behaviour. These phenomena impede the absorption and thermalization of the incoming laser energy, create groups of fast electrons and also may lead to a non-linear reflection of the heating laser beam. One of the key processes leading to the electron acceleration is the stimulated Raman scattering (SRS in its non-linear phase. The SRS in the presence of electron-ion collisions requires a certain threshold intensity above which the mentioned non-dissipative phenomena can occur and develop to the stage, where they may become unpleasant for the fusion experiments. To assess this intensity limit a computational model has been developed based on the Vlasov-Maxwell kinetics describing such a plasma in 1D geometry. At a relatively high intensity of 1016 W/cm2 a number of non-linear phenomena are predicted by the code such as a saturation of Landau damping, which is then translated in an unfavourable time dependence of the reflected light intensity and formation of accelerated electron groups due to the electron trapping. The purpose of the present contribution is to map the intensity dependence of this non-linear development with the aim of assessing its weight in fusion relevant situations.

Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

Science.gov (United States)

Amusa, Oyintola Isiaka; Atinmo, Morayo

2016-01-01

(Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

Nanoscale spin-dependent transport of electrons and holes in Si-ferromagnet structures

NARCIS (Netherlands)

Ul Haq, E.

Given the rapid development of magnetic data storage and spin-electronics into the realm of nanotechnology, the understanding of the spin-dependent electronic transport and switching behavior of magnetic structures at the nanoscale is an important issue. We have developed spin-sensitive techniques

A systematic review of portable electronic technology for health education in resource-limited settings.

Science.gov (United States)

McHenry, Megan S; Fischer, Lydia J; Chun, Yeona; Vreeman, Rachel C

2017-08-01

The objective of this study is to conduct a systematic review of the literature of how portable electronic technologies with offline functionality are perceived and used to provide health education in resource-limited settings. Three reviewers evaluated articles and performed a bibliography search to identify studies describing health education delivered by portable electronic device with offline functionality in low- or middle-income countries. Data extracted included: study population; study design and type of analysis; type of technology used; method of use; setting of technology use; impact on caregivers, patients, or overall health outcomes; and reported limitations. Searches yielded 5514 unique titles. Out of 75 critically reviewed full-text articles, 10 met inclusion criteria. Study locations included Botswana, Peru, Kenya, Thailand, Nigeria, India, Ghana, and Tanzania. Topics addressed included: development of healthcare worker training modules, clinical decision support tools, patient education tools, perceptions and usability of portable electronic technology, and comparisons of technologies and/or mobile applications. Studies primarily looked at the assessment of developed educational modules on trainee health knowledge, perceptions and usability of technology, and comparisons of technologies. Overall, studies reported positive results for portable electronic device-based health education, frequently reporting increased provider/patient knowledge, improved patient outcomes in both quality of care and management, increased provider comfort level with technology, and an environment characterized by increased levels of technology-based, informal learning situations. Negative assessments included high investment costs, lack of technical support, and fear of device theft. While the research is limited, portable electronic educational resources present promising avenues to increase access to effective health education in resource-limited settings, contingent

Bias-dependent oscillatory electron transport of monatomic sulfur chains

KAUST Repository

Yu, Jing-Xin; Cheng, Yan; Sanvito, Stefano; Chen, Xiang-Rong

2012-01-01

The bias-dependent oscillatory electron transport of monatomic sulfur chains sandwiched between gold electrodes is investigated with density functional theory and non-equilibrium Green's function method. At zero bias, in contrast to the typical odd-even oscillations observed in most metallic chains, we find that the conductance oscillates with a period of four atoms. However, as the bias voltage is increased the current displays a two-atom periodicity. This emerges gradually, first for the longer chains and then, at voltages larger than 0.7 V, for lengths. The oscillatory behaviors are analyzed by the density of states and the energy-dependent and bias-dependent transmission coefficients. © 2012 American Institute of Physics.

Bias-dependent oscillatory electron transport of monatomic sulfur chains

KAUST Repository

Yu, Jing-Xin

2012-01-01

The bias-dependent oscillatory electron transport of monatomic sulfur chains sandwiched between gold electrodes is investigated with density functional theory and non-equilibrium Green\\'s function method. At zero bias, in contrast to the typical odd-even oscillations observed in most metallic chains, we find that the conductance oscillates with a period of four atoms. However, as the bias voltage is increased the current displays a two-atom periodicity. This emerges gradually, first for the longer chains and then, at voltages larger than 0.7 V, for lengths. The oscillatory behaviors are analyzed by the density of states and the energy-dependent and bias-dependent transmission coefficients. © 2012 American Institute of Physics.

Transfer of Japanese Human Resource Management to US Subsidiaries: Resource Dependence Theory and Institutionalism

Directory of Open Access Journals (Sweden)

Hisako Matsuo, Ph.D.

2013-07-01

Full Text Available Japanese corporations are characterized by distinctive management practices which have been nurtured in a culturally homogeneous environment. The transferability of these practices to foreign subsidiaries has been a subject of debate among management scholars. Drawing on resource dependence theory and institutionalism, this study examines the impact of homogeneity in management and parent company control on the degree of presence of Japanese human resource management (HRM in U.S. subsidiaries. The study uses Walton and Lawrence’s classification (reward, selection and promotion, employee influence mechanism, and job design to measure uniquely Japanese HRM and a sample survey of 138 U.S. subsidiaries of Japanese multinational corporations for data collection. A principal component analysis reveals that three dimensions of HRM (reward system, selection and promotion, and job design, rather than four, are salient among these establishments. An OLS regression analysis also reveals that the degree of homogeneity in management and parent company control has impact on the transfer of these dimensions of HRM. Some implications for future study are discussed.

SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

Directory of Open Access Journals (Sweden)

Sheri L Lewis

Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

Directory of Open Access Journals (Sweden)

Mohammad Reza Davarpanah

2012-07-01

Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

New formula for dependence of molecular electronic energy on internuclear distance

International Nuclear Information System (INIS)

Rebane, T.K.

1988-01-01

We formulate an integral virial theorem which connects the change in the molecular electronic energy during finite changes in the size of the nuclear core (in the case of a diatomic molecule, during finite changes of the internuclear distance) with a matrix element of the kinetic electronic energy operator and with an overlap integral between wave functions. Our results can be used to calculate the dependence of the molecular electronic energy on the internuclear distance, as well as to check the quality of, and to improve, the approximate electronic wave functions. The theory is illustrated by the simplest example of the approximate MO LCAO wave function for the hydrogen molecular ion

Electron-Spin Precession in Dependence of the Orientation of the External Magnetic Field.

Science.gov (United States)

Miah, M Idrish

2009-03-13

Electron-spin dynamics in semiconductor-based heterostructures has been investigated in oblique magnetic fields. Spins are generated optically by a circularly polarized light, and the dynamics of spins in dependence of the orientation (theta) of the magnetic field are studied. The electron-spin precession frequency, polarization amplitude, and decay rate as a function of theta are obtained and the reasons for their dependences are discussed. From the measured data, the values of the longitudinal and transverse components of the electron g-factor are estimated and are found to be in good agreement with those obtained in earlier investigations. The possible mechanisms responsible for the observed effects are also discussed.

Spin dependent transport of hot electrons through ultrathin epitaxial metallic films

Energy Technology Data Exchange (ETDEWEB)

Heindl, Emanuel

2010-06-23

In this work relaxation and transport of hot electrons in thin single crystalline metallic films is investigated by Ballistic Electron Emission Microscopy. The electron mean free paths are determined in an energy interval of 1 to 2 eV above the Fermi level. While fcc Au-films appear to be quite transmissive for hot electrons, the scattering lengths are much shorter for the ferromagnetic alloy FeCo revealing, furthermore, a strong spin asymmetry in hot electron transport. Additional information is gained from temperature dependent studies in combination with golden rule approaches in order to disentangle the impact of several relaxation and transport properties. It is found that bcc Fe-films are much less effective in spin filtering than films made of the FeCo-alloy. (orig.)

Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

Science.gov (United States)

Sahu, H. K.; Singh, S. N.

2015-04-01

This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

Dependence of electron inelastic mean free paths on electron energy and materials at low energy region, 1

International Nuclear Information System (INIS)

Tanuma, Shigeo; Powell, C.J.; Penn, D.R.

1990-01-01

We have proposed a general formula of electron inelastic mean free path (IMFP) to describe the calculated IMFPs over the 50-2000 eV energy range based on the Inokuti's modified Bethe formula for the inelastic scattering cross section. The IMFPs for 50-2000 eV electrons in 27 elements were calculated using Penn's algorithm. The IMFP dependence on electron energy in the range 50-200 eV varies considerably from material to material. These variations are associated with substantial differences in the electron energy-loss functions amongst the material. We also found that the modified Bethe formula by Inokuti could be fitted to the calculated IMFPs in the range 50-2000 eV within 3% relative error. (author)

Dependence of Energetic Electron Precipitation on the Geomagnetic Index Kp and Electron Energy

Directory of Open Access Journals (Sweden)

Mi-Young Park

2013-12-01

Full Text Available It has long been known that the magnetospheric particles can precipitate into the atmosphere of the Earth. In this paper we examine such precipitation of energetic electrons using the data obtained from low-altitude polar orbiting satellite observations. We analyze the precipitating electron flux data for many periods selected from a total of 84 storm events identified for 2001-2012. The analysis includes the dependence of precipitation on the Kp index and the electron energy, for which we use three energies E1 > 30 keV, E2 > 100 keV, E3 > 300 keV. We find that the precipitation is best correlated with Kp after a time delay of < 3 hours. Most importantly, the correlation with Kp is notably tighter for lower energy than for higher energy in the sense that the lower energy precipitation flux increases more rapidly with Kp than does the higher energy precipitation flux. Based on this we suggest that the Kp index reflects excitation of a wave that is responsible for scattering of preferably lower energy electrons. The role of waves of other types should become increasingly important for higher energy, for which we suggest to rely on other indicators than Kp if one can identify such an indicator.

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

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.

Electronic transport coefficients in plasmas using an effective energy-dependent electron-ion collision-frequency

Science.gov (United States)

Faussurier, G.; Blancard, C.; Combis, P.; Decoster, A.; Videau, L.

2017-10-01

We present a model to calculate the electrical and thermal electronic conductivities in plasmas using the Chester-Thellung-Kubo-Greenwood approach coupled with the Kramers approximation. The divergence in photon energy at low values is eliminated using a regularization scheme with an effective energy-dependent electron-ion collision-frequency. Doing so, we interpolate smoothly between the Drude-like and the Spitzer-like regularizations. The model still satisfies the well-known sum rule over the electrical conductivity. Such kind of approximation is also naturally extended to the average-atom model. A particular attention is paid to the Lorenz number. Its nondegenerate and degenerate limits are given and the transition towards the Drude-like limit is proved in the Kramers approximation.

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.

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

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.)

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.)

[Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

Science.gov (United States)

Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

2006-01-01

Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

Model of e-learning with electronic educational resources of new generation

OpenAIRE

A. V. Loban; D. A. Lovtsov

2017-01-01

Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with elec...

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

Material dependence of electron inelastic mean free paths at low energies

International Nuclear Information System (INIS)

Tanuma, S.; Powell, C.J.; Penn, D.R.

1990-01-01

We present and discuss electron inelastic mean free path (IMFP) data for aluminum and gold in the 50--200 eV range. These elements serve as examples of IMFP calculations that have been made for 50--2000 eV electrons in 31 materials (27 elements and 4 compounds). Substantial differences are found in the shapes of the IMFP versus energy curves for Al and Au and these can be understood in terms of the different inelastic scattering mechanisms in the two metals. The minimum IMFP value occurs at 40 eV in aluminum and at 120 eV in gold, a result which is consistent with the trends expected from free-electron IMFP calculations. This result differs, however, from that expected from the Seah and Dench attenuation length formula which shows essentially no material dependence at low energies. We have extended a general formula derived earlier to describe the calculated IMFPs over the 200--2000 eV energy range to give the IMFP dependences on material and energy from 50 to 2000 eV

Momentum distribution dependence of induced electron-cyclotron emission

International Nuclear Information System (INIS)

Ziebell, L.F.; Dillenburg, D.

1983-01-01

The dependence of the electron-cyclotron wave amplification in an inhomogeneous plasma slab on the electron momentum distribution is investigated. Two types of distributions are considered, both featuring a loss cone and a Maxwellian component. It is shown that the perpendicular emission at the fundamental frequency is in general greatly reduced by the presence of a Maxwellian component and situations occur in which a layer in the slab very effectively absorbs all the radiation amplified elsewhere. The transition from the pure loss cone to the pure Maxwellian case is accompanied by a peculiar behaviour of the dielectric tensor components, which may invalidate the geometrical optics approximation in the calculation of the emission and the commonly held belief that the real part of the refractive index is insensitive to the shape of the momentum distribution function. (Author) [pt

Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

Science.gov (United States)

Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

2012-01-01

Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

Electronically induced nuclear transitions - temperature dependence and Rabi oscillations

International Nuclear Information System (INIS)

Niez, J.J.

2002-01-01

This paper deals with a nucleus electromagnetically coupled with the bound states of its electronic surroundings. It describes the temperature dependence of its dynamics and the onset of potential Rabi oscillations by means of a Master Equation. The latter is generalized in order to account for possible strong resonances. Throughout the paper the approximation schemes are discussed and tested. (authors)

Brain state-dependence of electrically evoked potentials monitored with head-mounted electronics.

Science.gov (United States)

Richardson, Andrew G; Fetz, Eberhard E

2012-11-01

Inferring changes in brain connectivity is critical to studies of learning-related plasticity and stimulus-induced conditioning of neural circuits. In addition, monitoring spontaneous fluctuations in connectivity can provide insight into information processing during different brain states. Here, we quantified state-dependent connectivity changes throughout the 24-h sleep-wake cycle in freely behaving monkeys. A novel, head-mounted electronic device was used to electrically stimulate at one site and record evoked potentials at other sites. Electrically evoked potentials (EEPs) revealed the connectivity pattern between several cortical sites and the basal forebrain. We quantified state-dependent changes in the EEPs. Cortico-cortical EEP amplitude increased during slow-wave sleep, compared to wakefulness, while basal-cortical EEP amplitude decreased. The results demonstrate the utility of using portable electronics to document state-dependent connectivity changes in freely behaving primates.

Electronic Document Management: A Human Resource Management Case Study

Directory of Open Access Journals (Sweden)

Thomas Groenewald

2004-11-01

Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

Doping dependence of charge order in electron-doped cuprate superconductors

Science.gov (United States)

Mou, Yingping; Feng, Shiping

2017-12-01

In the recent studies of the unconventional physics in cuprate superconductors, one of the central issues is the interplay between charge order and superconductivity. Here the mechanism of the charge-order formation in the electron-doped cuprate superconductors is investigated based on the t-J model. The experimentally observed momentum dependence of the electron quasiparticle scattering rate is qualitatively reproduced, where the scattering rate is highly anisotropic in momentum space, and is intriguingly related to the charge-order gap. Although the scattering strength appears to be weakest at the hot spots, the scattering in the antinodal region is stronger than that in the nodal region, which leads to the original electron Fermi surface is broken up into the Fermi pockets and their coexistence with the Fermi arcs located around the nodal region. In particular, this electron Fermi surface instability drives the charge-order correlation, with the charge-order wave vector that matches well with the wave vector connecting the hot spots, as the charge-order correlation in the hole-doped counterparts. However, in a striking contrast to the hole-doped case, the charge-order wave vector in the electron-doped side increases in magnitude with the electron doping. The theory also shows the existence of a quantitative link between the single-electron fermiology and the collective response of the electron density.

Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

Directory of Open Access Journals (Sweden)

Soto Giselle

2008-11-01

Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

Temperature dependence of the electronic structure of semiconductors and insulators

Energy Technology Data Exchange (ETDEWEB)

Poncé, S., E-mail: samuel.pon@gmail.com; Gillet, Y.; Laflamme Janssen, J.; Gonze, X. [European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve (Belgium); Marini, A. [Consiglio Nazionale delle Ricerche (CNR), Via Salaria Km 29.3, CP 10, 00016 Monterotondo Stazione (Italy); Verstraete, M. [European Theoretical Spectroscopy Facility and Physique des matériaux et nanostructures, Université de Liège, Allée du 6 Août 17, B-4000 Liège (Belgium)

2015-09-14

The renormalization of electronic eigenenergies due to electron-phonon coupling (temperature dependence and zero-point motion effect) is sizable in many materials with light atoms. This effect, often neglected in ab initio calculations, can be computed using the perturbation-based Allen-Heine-Cardona theory in the adiabatic or non-adiabatic harmonic approximation. After a short description of the recent progresses in this field and a brief overview of the theory, we focus on the issue of phonon wavevector sampling convergence, until now poorly understood. Indeed, the renormalization is obtained numerically through a slowly converging q-point integration. For non-zero Born effective charges, we show that a divergence appears in the electron-phonon matrix elements at q → Γ, leading to a divergence of the adiabatic renormalization at band extrema. This problem is exacerbated by the slow convergence of Born effective charges with electronic wavevector sampling, which leaves residual Born effective charges in ab initio calculations on materials that are physically devoid of such charges. Here, we propose a solution that improves this convergence. However, for materials where Born effective charges are physically non-zero, the divergence of the renormalization indicates a breakdown of the adiabatic harmonic approximation, which we assess here by switching to the non-adiabatic harmonic approximation. Also, we study the convergence behavior of the renormalization and develop reliable extrapolation schemes to obtain the converged results. Finally, the adiabatic and non-adiabatic theories, with corrections for the slow Born effective charge convergence problem (and the associated divergence) are applied to the study of five semiconductors and insulators: α-AlN, β-AlN, BN, diamond, and silicon. For these five materials, we present the zero-point renormalization, temperature dependence, phonon-induced lifetime broadening, and the renormalized electronic band structure.

Spin-dependent electron emission from metals in the neutralization of He+ ions

International Nuclear Information System (INIS)

Alducin, M.; Roesler, M.; Juaristi, J.I.; Muino, R. Diez; Echenique, P.M.

2005-01-01

We calculate the spin-polarization of electrons emitted in the neutralization of He + ions interacting with metals. All stages of the emission process are included: the spin-dependent perturbation induced by the projectile, the excitation of electrons in Auger neutralization processes, the creation of a cascade of secondaries, and the escape of the electrons through the surface potential barrier. The model allows us to explain in quantitative terms the measured spin-polarization of the yield in the interaction of spin-polarized He + ions with paramagnetic surfaces, and to disentangle the role played by each of the involved mechanisms. We show that electron-electron scattering processes at the surface determine the spin-polarization of the total yield. High energy emitted electrons are the ones providing direct information on the He + ion neutralization process and on the electronic properties of the surface

Electron transport in furfural: dependence of the electron ranges on the cross sections and the energy loss distribution functions

Science.gov (United States)

Ellis-Gibbings, L.; Krupa, K.; Colmenares, R.; Blanco, F.; Muńoz, A.; Mendes, M.; Ferreira da Silva, F.; Limá Vieira, P.; Jones, D. B.; Brunger, M. J.; García, G.

2016-09-01

Recent theoretical and experimental studies have provided a complete set of differential and integral electron scattering cross section data from furfural over a broad energy range. The energy loss distribution functions have been determined in this study by averaging electron energy loss spectra for different incident energies and scattering angles. All these data have been used as input parameters for an event by event Monte Carlo simulation procedure to obtain the electron energy deposition patterns and electron ranges in liquid furfural. The dependence of these results on the input cross sections is then analysed to determine the uncertainty of the simulated values.

Electronic Information Access and Utilization by Makerere University Students in Uganda

Directory of Open Access Journals (Sweden)

Elisam Magara

2008-09-01

Full Text Available Objectives – The objectives of this study were to establish the level of computer utilization skills of Makerere University (Uganda Library and Information Science (LIS students; to determine the use of electronic information resources by LIS students; to determine the attitudes of LIS students towards electronic information resources; and to establish the problems faced by LIS students in accessing electronic information resources.Methods – A questionnaire survey was used for data collection.Results – The majority of Library and Information Science students at Makerere University depend on university computers for their work, and very few of them access the library’s e-resources. The few who access e-resources are self-taught. The majority of students surveyed were unaware of Emerald and EBSCO databases relevant to Library and Information Science students, and they found accessing eresources time-consuming. Conclusion – The study concluded that a concerted effort is needed by both LIS lecturers and university librarians in promoting use of the library’s electronic resources.

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.

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...

Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

Science.gov (United States)

Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

2015-09-01

Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

Charge-state dependence of binary-encounter-electron cross sections and peak energies

International Nuclear Information System (INIS)

Hidmi, H.I.; Richard, P.; Sanders, J.M.; Schoene, H.; Giese, J.P.; Lee, D.H.; Zouros, T.J.M.; Varghese, S.L.

1993-01-01

The charge-state dependence of the binary-encounter-electron (BEE) double-differential cross section (DDCS) at 0 degree with respect to the beam direction resulting from collisions of 1 MeV/amu H + , C q+ , N q+ , O q+ , F q+ , Si q+ , and Cl q+ , and 0.5 MeV/amu Cu q+ with H 2 is reported. The data show an enhancement in the BEE DDCS as the charge state of the projectile is decreased, in agreement with the data reported by Richard et al. [J. Phys. B 23, L213 (1990)]. The DDCS enhancement ratios observed for the three-electron isoelectronic sequence C 3+ :C 6+ , N 4+ :N 7+ , O 5+ :O 8+ , and F 6+ :F 9+ are about 1.35, whereas a DDCS enhancement of 3.5 was observed for Cu 4+ . The BEE enhancement with increasing electrons on the projectile has been shown by several authors to be due to the non-Coulomb static potential of the projectile and additionally to the e-e exchange interaction. An impulse-approximation (IA) model fits the shape of the BEE DDCS and predicts a Z p 2 dependence for the bare-ion cross sections. The IA also predicts a binary peak energy that is independent of q and Z p and below the classical value of 4t, where t is the energy of electrons traveling with the projectile velocity. We observed a BEE energy shift ΔE (ΔE=4t-E peak , where E peak is the measured energy at the peak of the binary encounter electrons) that is approximately independent of q for the low-Z p ions, whereas the measured ΔE values for Si, Cl, and Cu were found to be q dependent

pH-dependent electron transfer reaction and direct bioelectrocatalysis of the quinohemoprotein pyranose dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

Takeda, Kouta [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Matsumura, Hirotoshi; Ishida, Takuya [Department of Biomaterial Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 (Japan); Yoshida, Makoto [Department of Environmental and Natural Resource Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Igarashi, Kiyohiko; Samejima, Masahiro [Department of Biomaterial Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 (Japan); Ohno, Hiroyuki [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Nakamura, Nobuhumi, E-mail: nobu1@cc.tuat.ac.jp [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan)

2016-08-26

A pyranose dehydrogenase from Coprinopsis cinerea (CcPDH) is an extracellular quinohemoeprotein, which consists a b-type cytochrome domain, a pyrroloquinoline-quinone (PQQ) domain, and a family 1-type carbohydrate-binding module. The electron transfer reaction of CcPDH was studied using some electron acceptors and a carbon electrode at various pH levels. Phenazine methosulfate (PMS) reacted directly at the PQQ domain, whereas cytochrome c (cyt c) reacted via the cytochrome domain of intact CcPDH. Thus, electrons are transferred from reduced PQQ in the catalytic domain of CcPDH to heme b in the N-terminal cytochrome domain, which acts as a built-in mediator and transfers electron to a heterogenous electron transfer protein. The optimal pH values of the PMS reduction (pH 6.5) and the cyt c reduction (pH 8.5) differ. The catalytic currents for the oxidation of L-fucose were observed within a range of pH 4.5 to 11. Bioelectrocatalysis of CcPDH based on direct electron transfer demonstrated that the pH profile of the biocatalytic current was similar to the reduction activity of cyt c characters. - Highlights: • pH dependencies of activity were different for the reduction of cyt c and DCPIP. • DET-based bioelectrocatalysis of CcPDH was observed. • The similar pH-dependent profile was found with cyt c and electrode. • The present results suggested that IET reaction of CcPDH shows pH dependence.

Anomaly in the Kumakhov radiation temperature dependence at axial channeling of electrons

Energy Technology Data Exchange (ETDEWEB)

Komarov, F.F.; Telegin, V.I.; Khokonov, M.Kh.

1983-01-01

The results of numerical solution of a kinetic equation for distribution function of axially channelled electrons obtained by Belostritsky and Kumakhov at different temperatures of crystals and calculated for the determined electron distributions spectral density of radiation are given. Analysis of the obtained dependence of the number of channelled 5 GeV electrons in tungsten along the <111> axis on depth Z has revealed that 2% of incidence beam electrons have anomalously large depths of dechannelling. Ratio of electrons with large by modulus cross section energies grows at decreasing crystal temperature from 293 to 40 K and, therefore, radiation intensity increases. Two-fold increase of radiation intensity can be attained at axial channelling of 1 GeV electrons in tungsten <111> at the temperatures of the crystal equal to 40 and 293 K and its thickness equal to 220 ..mu..m.

Resource conservation approached with an appropriate collection and upgrade-remanufacturing for used electronic products.

Science.gov (United States)

Zlamparet, Gabriel I; Tan, Quanyin; Stevels, A B; Li, Jinhui

2018-03-01

This comparative research represents an example for a better conservation of resources by reducing the amount of waste (kg) and providing it more value under the umbrella of remanufacturing. The three discussed cases will expose three issues already addressed separately in the literature. The generation of waste electrical and electronic equipment (WEEE) interacts with the environmental depletion. In this article, we gave the examples of addressed issues under the concept of remanufacturing. Online collection opportunity eliminating classical collection, a business to business (B2B) implementation for remanufactured servers and medical devices. The material reuse (recycling), component sustainability, reuse (part harvesting), product reuse (after repair/remanufacturing) indicates the recovery potential using remanufacturing tool for a better conservation of resources adding more value to the products. Our findings can provide an overview of new system organization for the general collection, market potential and the technological advantages using remanufacturing instead of recycling of WEEE or used electrical and electronic equipment. Copyright © 2017. Published by Elsevier Ltd.

SANDYL, 3-D Time-Dependent and Space-Dependent Gamma Electron Cascade Transport by Monte-Carlo

International Nuclear Information System (INIS)

Haggmark, L.G.

1980-01-01

1 - Description of problem or function: SANDYL performs three- dimensional, time and space dependent Monte Carlo transport calculations for photon-electron cascades in complex systems. 2 - Method of solution: The problem geometry is divided into zones of homogeneous atomic composition bounded by sections of planes and quadrics. The material of each zone is a specified element or combination of elements. For a photon history, the trajectory is generated by following the photon from scattering to scattering using the various probability distributions to find distances between collisions, types of collisions, types of secondaries, and their energies and scattering angles. The photon interactions are photoelectric absorption (atomic ionization), coherent scattering, incoherent scattering, and pair production. The secondary photons which are followed include Bremsstrahlung, fluorescence photons, and positron-electron annihilation radiation. The condensed-history Monte Carlo method is used for the electron transport. In a history, the spatial steps taken by an electron are pre-computed and may include the effects of a number of collisions. The corresponding scattering angle and energy loss in the step are found from the multiple scattering distributions of these quantities. Atomic ionization and secondary particles are generated with the step according to the probabilities for their occurrence. Electron energy loss is through inelastic electron-electron collisions, Bremsstrahlung generation, and polarization of the medium (density effect). Included in the loss is the fluctuation due to the variation in the number of energy-loss collisions in a given Monte Carlo step (straggling). Scattering angular distributions are determined from elastic nuclear-collision cross sections corrected for electron-electron interactions. The secondary electrons which are followed included knock-on, pair, Auger (through atomic ionizations), Compton, and photoelectric electrons. 3

The temperature dependence of quantum spin pumping generated using electron spin resonance with three-magnon splittings

International Nuclear Information System (INIS)

Nakata, Kouki

2013-01-01

On the basis of the Schwinger–Keldysh formalism, we have closely investigated the temperature dependence of quantum spin pumping generated using electron spin resonance. We have clarified that three-magnon splittings excite non-zero modes of magnons and characterize the temperature dependence of quantum spin pumping generated using electron spin resonance. (paper)

Effects of the Use of Electronic Human Resource Management (EHRM Within Human Resource Management (HRM Functions at Universities

Directory of Open Access Journals (Sweden)

Chux Gervase Iwu

2016-09-01

Full Text Available This study set out to examine the effect of e-hrm systems in assisting human resource practitioners to execute their duties and responsibilities. In comparison to developed economies of the world, information technology adoption in sub-Saharan Africa has not been without certain glitches. Some of the factors that are responsible for these include poor need identification, sustainable funding, and insufficient skills. Besides these factors, there is also the issue of change management and users sticking to what they already know. Although, the above factors seem negative, there is strong evidence that information systems such as electronic human resource management present benefits to an organization. To achieve this, a dual research approach was utilized. Literature assisted immensely in both the development of the conceptual framework upon which the study hinged as well as in the development of the questionnaire items. The study also made use of an interview checklist to guide the participants. The findings reveal a mix of responses that indicate that while there are gains in adopting e-hrm systems, it is wiser to consider supporting resources as well as articulate the needs of the university better before any investment is made.

Electronic human resource management: Enhancing or entrancing?

Directory of Open Access Journals (Sweden)

Paul Poisat

2017-07-01

Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

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.

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.

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.

Energy and integrated dose dependence of MOSFET dosimeter for clinical electron beams

International Nuclear Information System (INIS)

Manigandan, D.; Bharanidharan, G.; Aruna, P.; Ganesan, S.; Tamil Kumar, T.; Rai

2008-01-01

In this study, the sensitivity (mV/cGy) and integral dose dependence of a MOSFET detector for different clinical electron beams was studied. Calibrated clinical electron beams (Varian 2100) were used for the exposure. A Markus type parallel plate chamber was used for the absolute dose measurements. In order to study the sensitivity of a MOSFET, the response of the ion chamber and MOSFET for the absorbed dose of 100 cGy was measured. The sensitivity of the MOSFET was then expressed as mV/cGy. Sensitivity was measured for 4-18 MeV electron beams. (author)

Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

Science.gov (United States)

Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

2014-01-01

Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

Systematic review of electronic surveillance of infectious diseases with emphasis on antimicrobial resistance surveillance in resource-limited settings.

Science.gov (United States)

Rattanaumpawan, Pinyo; Boonyasiri, Adhiratha; Vong, Sirenda; Thamlikitkul, Visanu

2018-02-01

Electronic surveillance of infectious diseases involves rapidly collecting, collating, and analyzing vast amounts of data from interrelated multiple databases. Although many developed countries have invested in electronic surveillance for infectious diseases, the system still presents a challenge for resource-limited health care settings. We conducted a systematic review by performing a comprehensive literature search on MEDLINE (January 2000-December 2015) to identify studies relevant to electronic surveillance of infectious diseases. Study characteristics and results were extracted and systematically reviewed by 3 infectious disease physicians. A total of 110 studies were included. Most surveillance systems were developed and implemented in high-income countries; less than one-quarter were conducted in low-or middle-income countries. Information technologies can be used to facilitate the process of obtaining laboratory, clinical, and pharmacologic data for the surveillance of infectious diseases, including antimicrobial resistance (AMR) infections. These novel systems require greater resources; however, we found that using electronic surveillance systems could result in shorter times to detect targeted infectious diseases and improvement of data collection. This study highlights a lack of resources in areas where an effective, rapid surveillance system is most needed. The availability of information technology for the electronic surveillance of infectious diseases, including AMR infections, will facilitate the prevention and containment of such emerging infectious diseases. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-01-01

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables

Dependence of electron peak current on hollow cathode dimensions and seed electron energy in a pseudospark discharge

International Nuclear Information System (INIS)

Cetiner, S. O.; Stoltz, P.; Messmer, P.; Cambier, J.-L.

2008-01-01

The prebreakdown and breakdown phases of a pseudospark discharge are investigated using the two-dimensional kinetic plasma simulation code OOPIC PRO. Trends in the peak electron current at the anode are presented as function of the hollow cathode dimensions and mean seed injection velocities at the cavity back wall. The plasma generation process by ionizing collisions is examined, showing the effect on supplying the electrons that determine the density of the beam. The mean seed velocities used here are varied between the velocity corresponding to the energy of peak ionization cross section, 15 times this value and no mean velocity (i.e., electrons injected with a temperature of 2.5 eV). The reliance of the discharge characteristics on the penetrating electric field is shown to decrease as the mean seed injection velocity increases because of its ability to generate a surplus plasma independent of the virtual anode. As a result, the peak current increases with the hollow cathode dimensions for the largest average injection velocity, while for the smallest value it increases with the area of penetration of the electric field in the hollow cathode interior. Additionally, for a given geometry an increase in the peak current with the surplus plasma generated is observed. For the largest seed injection velocity used a dependence of the magnitude of the peak current on the ratio of the hole thickness and hollow cathode depth to the hole height is demonstrated. This means similar trends of the peak current are generated when the geometry is resized. Although the present study uses argon only, the variation in the discharge dependencies with the seed injection energy relative to the ionization threshold is expected to apply independently of the gas type. Secondary electrons due to electron and ion impact are shown to be important only for the largest impact areas and discharge development times of the study

Exploratory Inquiry: Fundraising at Historically Black Colleges and Universities to Reduce Resource Dependence

Science.gov (United States)

Mills Campbell, Dawn

2017-01-01

Resource dependence has been evidenced among private HBCUs that obtain as much as 90% of operating revenue from tuition and fees. Without alternative funding strategies in place, small declines in enrollment can lead to a major budget crisis. The basic premise of this exploratory inquiry was that fundraising represents an opportunity that has been…

Effect of field-dependent mobility on the escape probability. I. Electrons photoinjected in neopentane

International Nuclear Information System (INIS)

Mozumder, A.; Carmichael, I.

1978-01-01

A general procedure is described for calculating the escape probability of an electron against neutralization in the presence of an external field after it has been ejected into a dielectric liquid from a planar surface. The present paper utilizes the field-dependent electron mobility measurement in neopentane by Bakale and Schmidt. The calculated escape probability, upon averaging over the initial distribution, is compared with the current efficiency measurement of Holroyd et al. The median thermalization legnth, inferred from this comparison, depends in general upon the assumed form of initial distribution. It is less than the value obtained when the field dependence of the mobility is ignored but greater than that applicable to the high energy irradiation case. A plausible explanation is offered

Origin of spin-dependent asymmetries in electron transmission through ultrathin ferromagnetic films

International Nuclear Information System (INIS)

Gokhale, M.P.; Mills, D.L.

1991-01-01

We present theoretical calculations of exchange asymmetries in the transmission of electrons through ultrathin films of ferromagnetic Fe. The results account nicely for the magnitude of the asymmetries observed by Pappas et al. in photoemission studies of Cu covered by an ultrathin film of Fe. We argue that exchange asymmetry in the transmissivity of the Fe film, rather than the spin dependence of the electron mean free path, is responsible for the effects reported by these authors

Open-Source Electronic Health Record Systems for Low-Resource Settings: Systematic Review.

Science.gov (United States)

Syzdykova, Assel; Malta, André; Zolfo, Maria; Diro, Ermias; Oliveira, José Luis

2017-11-13

Despite the great impact of information and communication technologies on clinical practice and on the quality of health services, this trend has been almost exclusive to developed countries, whereas countries with poor resources suffer from many economic and social issues that have hindered the real benefits of electronic health (eHealth) tools. As a component of eHealth systems, electronic health records (EHRs) play a fundamental role in patient management and effective medical care services. Thus, the adoption of EHRs in regions with a lack of infrastructure, untrained staff, and ill-equipped health care providers is an important task. However, the main barrier to adopting EHR software in low- and middle-income countries is the cost of its purchase and maintenance, which highlights the open-source approach as a good solution for these underserved areas. The aim of this study was to conduct a systematic review of open-source EHR systems based on the requirements and limitations of low-resource settings. First, we reviewed existing literature on the comparison of available open-source solutions. In close collaboration with the University of Gondar Hospital, Ethiopia, we identified common limitations in poor resource environments and also the main requirements that EHRs should support. Then, we extensively evaluated the current open-source EHR solutions, discussing their strengths and weaknesses, and their appropriateness to fulfill a predefined set of features relevant for low-resource settings. The evaluation methodology allowed assessment of several key aspects of available solutions that are as follows: (1) integrated applications, (2) configurable reports, (3) custom reports, (4) custom forms, (5) interoperability, (6) coding systems, (7) authentication methods, (8) patient portal, (9) access control model, (10) cryptographic features, (11) flexible data model, (12) offline support, (13) native client, (14) Web client,(15) other clients, (16) code

Home and Parenting Resources Available to Siblings Depending on Their Birth Intention Status

Science.gov (United States)

Barber, Jennifer S.; East, Patricia L.

2009-01-01

This study examines the differential availability of family and parenting resources to children depending on their birth planning status. The National Longitudinal Survey of Youth data were analyzed, 3,134 mothers and their 5,890 children (M = 7.1 years, range = 1 month-14.8 years), of whom 63% were intended at conception, 27% were mistimed, and…

On the length dependence of bridge-mediated electron transfer reactions

International Nuclear Information System (INIS)

Petrov, E.G.; Shevchenko, Ye.V.; May, V.

2003-01-01

Bridge-mediated nonadiabatic donor-acceptor (D-A) electron transfer (ET) is studied for the case of a regular molecular bridge of N identical units. It is shown that the multi-exponential ET kinetics reduces to a single-exponential transfer if, and only if, the integral population of the bridge remains small (less than 10 -2 ). An analytical expression for the overall D-A ET rate is derived and the necessary and sufficient conditions are formulated at which the rate is given as a sum of a superexchange and a sequential contribution. To describe experimental data on the N-dependence of ET reactions an approximate form of the overall transfer rate is derived. This expression is used to reproduce experimental data on distant ET through polyproline chains. Finally it is noted that the obtained analytical results can also be used for the description of more complex two-electron transfer reactions if the latter comprises separate single-electron pathways

Electron-Spin Precession in Dependence of the Orientation of the External Magnetic Field

Directory of Open Access Journals (Sweden)

Miah M

2009-01-01

Full Text Available Abstract Electron-spin dynamics in semiconductor-based heterostructures has been investigated in oblique magnetic fields. Spins are generated optically by a circularly polarized light, and the dynamics of spins in dependence of the orientation (θ of the magnetic field are studied. The electron-spin precession frequency, polarization amplitude, and decay rate as a function ofθare obtained and the reasons for their dependences are discussed. From the measured data, the values of the longitudinal and transverse components of the electrong-factor are estimated and are found to be in good agreement with those obtained in earlier investigations. The possible mechanisms responsible for the observed effects are also discussed.

Regulation of energy partitioning and alternative electron transport pathways during cold acclimation of lodgepole pine is oxygen dependent.

Science.gov (United States)

Savitch, Leonid V; Ivanov, Alexander G; Krol, Marianna; Sprott, David P; Oquist, Gunnar; Huner, Norman P A

2010-09-01

Second year needles of Lodgepole pine (Pinus contorta L.) were exposed for 6 weeks to either simulated control summer ['summer'; 25 °C/250 photon flux denisty (PFD)], autumn ('autumn'; 15°C/250 PFD) or winter conditions ('winter'; 5 °C/250 PFD). We report that the proportion of linear electron transport utilized in carbon assimilation (ETR(CO2)) was 40% lower in both 'autumn' and 'winter' pine when compared with the 'summer' pine. In contrast, the proportion of excess photosynthetic linear electron transport (ETR(excess)) not used for carbon assimilation within the total ETR(Jf) increased by 30% in both 'autumn' and 'winter' pine. In 'autumn' pine acclimated to 15°C, the increased amounts of 'excess' electrons were directed equally to 21  kPa O2-dependent and 2  kPa O2-dependent alternative electron transport pathways and the fractions of excitation light energy utilized by PSII photochemistry (Φ(PSII)), thermally dissipated through Φ(NPQ) and dissipated by additional quenching mechanism(s) (Φ(f,D)) were similar to those in 'summer' pine. In contrast, in 'winter' needles acclimated to 5 °C, 60% of photosynthetically generated 'excess' electrons were utilized through the 2  kPa O2-dependent electron sink and only 15% by the photorespiratory (21  kPa O2) electron pathway. Needles exposed to 'winter' conditions led to a 3-fold lower Φ(PSII), only a marginal increase in Φ(NPQ) and a 2-fold higher Φ(f,D), which was O2 dependent compared with the 'summer' and 'autumn' pine. Our results demonstrate that the employment of a variety of alternative pathways for utilization of photosynthetically generated electrons by Lodgepole pine depends on the acclimation temperature. Furthermore, dissipation of excess light energy through constitutive non-photochemical quenching mechanisms is O2 dependent.

2D Spin-Dependent Diffraction of Electrons From Periodical Chains of Nanomagnets

Directory of Open Access Journals (Sweden)

Teshome Senbeta

2012-03-01

Full Text Available The scattering of the unpolarized beams of electrons by nanomagnets in the vicinity of some scattering angles leads to complete spin polarized electrons. This result is obtained with the help of the perturbation theory. The dipole-dipole interaction between the magnetic moment of the nanomagnet and the magnetic moment of electron is treated as perturbation. This interaction is not spherically symmetric. Rather it depends on the electron spin variables. It in turn results in spinor character of the scattering amplitudes. Due to the smallness of the magnetic interactions, the scattering length of this process is very small to be proved experimentally. To enhance the relevant scattering lengths, we considered the diffraction of unpolarized beams of electrons by linear chains of nanomagnets. By tuning the distance between the scatterers it is possible to obtain the diffraction maximum of the scattered electrons at scattering angles which corresponds to complete spin polarization of electrons. It is shown that the total differential scattering length is proportional to N2 (N is a number of scatterers. Even small number of nanomagnets in the chain helps to obtain experimentally visible enhancement of spin polarization of the scattered electrons.

Parameter Dependence of Inward Diffusion on Injected Electrons in Helical Non-Neutral Plasmas

International Nuclear Information System (INIS)

Wakabayashi, H.; Himura, H.; Fukao, M.; Yoshida, Z.

2003-01-01

Experimental studies on an electron injection into a helical magnetic field and characteristics of non-neutral plasmas have been performed. It is found that the space potential φs has a weak dependence on the injection angle except for a narrow 'window' region in which φs significantly drops. A calculation shows that because of the electric field Eg of the electron gun (e-gun), the emitted electrons are launched quasi-parallel to the helical magnetic field B, regardless of α. This seems to agree with the observation. The 'window' seen in the data may be attributed to an current-driven instability which might result in the insufficient electron penetration or the degradation of electron confinement in the magnetic surface

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.

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

Energy Technology Data Exchange (ETDEWEB)

Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2007-05-11

High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

International Nuclear Information System (INIS)

Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

2007-01-01

High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

Enhancing a Dependable Multiserver Operating System with Temporal Protection via Resource Reservations

OpenAIRE

Mancin , Antonio; Lipari , Giuseppe; Herder , Jorrit N.; Gras , Ben; Tanenbaum , Andrew S.

2008-01-01

International audience; MINIX 3 is a microkernel-based, multiserver operating system for uniprocessors that is designed to be highly dependable. Servers are restricted according to the principle of least privilege. For example, access to resources such as system memory and device I/O is fully protected. Although MINIX 3 is a potential candidate for embedded platforms, it currently cannot safeguard processes with stringent timing requirements, such as real-time applications. In this paper, we ...

To make or buy patient safety solutions: a resource dependence and transaction cost economics perspective.

Science.gov (United States)

Fareed, Naleef; Mick, Stephen S

2011-01-01

For almost a decade, public and private organizations have pressured hospitals to improve their patient safety records. Since 2008, the Centers for Medicare & Medicaid Services has no longer been reimbursing hospitals for secondary diagnoses not reported during the point of admission. This ruling has motivated some hospitals to engage in safety-oriented programs to decrease adverse events. This study examined which hospitals may engage in patient safety solutions and whether they create these patient safety solutions within their structures or use suppliers in the market. We used a theoretical model that incorporates the key constructs of resource dependence theory and transaction cost economics theory to predict a hospital's reaction to Centers for Medicare & Medicaid Services "never event" regulations. We present propositions that speculate on how forces conceptualized from the resource dependence theory may affect adoption of patient safety innovations and, when they do, whether the adopting hospitals will do so internally or externally according to the transaction cost economics theory. On the basis of forces identified by the resource dependence theory, we predict that larger, teaching, safety net, horizontally integrated, highly interdependent, and public hospitals in concentrated, high public payer presence, competitive, and resource-rich environments will be more likely to engage in patient safety innovations. Following the logic of the transaction cost economics theory, we predict that of the hospitals that react positively to the never event regulation, most will internalize their innovations in patient safety solutions rather than approach the market, a choice that helps hospitals economize on transaction costs. This study helps hospital managers in their strategic thinking and planning in relation to current and future regulations related to patient safety. For researchers and policy analysts, our propositions provide the basis for empirical testing.

Size dependence investigations of hot electron cooling dynamics in metal/adsorbates nanoparticles

International Nuclear Information System (INIS)

Bauer, Christophe; Abid, Jean-Pierre; Girault, Hubert H.

2005-01-01

The size dependence of electron-phonon coupling rate has been investigated by femtosecond transient absorption spectroscopy for gold nanoparticles (NPs) wrapped in a shell of sulfate with diameter varying from 1.7 to 9.2 nm. Broad-band spectroscopy gives an overview of the complex dynamics of nonequilibrium electrons and permits the choice of an appropriate probe wavelength for studying the electron-phonon coupling dynamics. Ultrafast experiments were performed in the weak perturbation regime (less than one photon in average per nanoparticle), which allows the direct extraction of the hot electron cooling rates in order to compare different NPs sizes under the same conditions. Spectroscopic data reveals a decrease of hot electron energy loss rates with metal/adsorbates nanosystem sizes. Electron-phonon coupling time constants obtained for 9.2 nm NPs are similar to gold bulk materials (∼1 ps) whereas an increase of hot electron cooling time up to 1.9 ps is observed for sizes of 1.7 nm. This is rationalized by the domination of surface effects over size (bulk) effects. The slow hot electron cooling is attributed to the adsorbates-induced long-lived nonthermal regime, which significantly reduces the electron-phonon coupling strength (average rate of phonon emission)

No Evidence of Trade-Off between Farm Efficiency and Resilience: Dependence of Resource-Use Efficiency on Land-Use Diversity.

Directory of Open Access Journals (Sweden)

Helena Kahiluoto

Full Text Available Efficiency in the use of resources stream-lined for expected conditions could lead to reduced system diversity and consequently endanger resilience. We tested the hypothesis of a trade-off between farm resource-use efficiency and land-use diversity. We applied stochastic frontier production models to assess the dependence of resource-use-efficiency on land-use diversity as illustrated by the Shannon-Weaver index. Total revenue in relation to use of capital, land and labour on the farms in Southern Finland with a size exceeding 30 ha was studied. The data were extracted from the Finnish Profitability Bookkeeping data. Our results indicate that there is either no trade-off or a negligible trade-off of no economic importance. The small dependence of resource-use efficiency on land-use diversity can be positive as well as negative. We conclude that diversification as a strategy to enhance farm resilience does not necessarily constrain resource-use efficiency.

Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division

Science.gov (United States)

Stiltner, G.J.

1990-01-01

In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration of software and hardware: Ventura Publisher software on an IBM model AT personal computer, PageMaker software on a Macintosh computer, and FrameMaker software on a Sun Microsystems workstation. The following assessment criteria were to be addressed in the pilot studies: The combined use of text, tables, and graphics; analysis of time; ease of learning; compatibility with the existing minicomputer system; and technical limitations. It was considered essential that the camera-ready copy produced be in a format suitable for publication. Visual improvement alone was not a consideration. This report consolidates and summarizes the findings of the electronic report processing pilot projects. Text and table files originating on the existing minicomputer system were successfully transformed to the electronic report processing systems in American Standard Code for Information Interchange (ASCII) format. Graphics prepared using a proprietary graphics software package were transferred to all the electronic report processing software through the use of Computer Graphic Metafiles. Graphics from other sources were entered into the systems by scanning paper images. Comparative analysis of time needed to process text and tables by the electronic report processing systems and by conventional methods indicated that, although more time is invested in creating the original page composition for an electronically processed report , substantial time is saved in producing subsequent reports because the format can be stored and re-used by electronic means as a template. Because of the more compact page layouts, costs of printing the reports were 15% to 25

Laser-induced electron dynamics including photoionization: A heuristic model within time-dependent configuration interaction theory.

Science.gov (United States)

Klinkusch, Stefan; Saalfrank, Peter; Klamroth, Tillmann

2009-09-21

We report simulations of laser-pulse driven many-electron dynamics by means of a simple, heuristic extension of the time-dependent configuration interaction singles (TD-CIS) approach. The extension allows for the treatment of ionizing states as nonstationary states with a finite, energy-dependent lifetime to account for above-threshold ionization losses in laser-driven many-electron dynamics. The extended TD-CIS method is applied to the following specific examples: (i) state-to-state transitions in the LiCN molecule which correspond to intramolecular charge transfer, (ii) creation of electronic wave packets in LiCN including wave packet analysis by pump-probe spectroscopy, and, finally, (iii) the effect of ionization on the dynamic polarizability of H(2) when calculated nonperturbatively by TD-CIS.

Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

Directory of Open Access Journals (Sweden)

Velmurugan Chandran

2013-12-01

Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

International Nuclear Information System (INIS)

Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

2011-01-01

Highlights: → End-of-life electrical and electronic equipment (EEE) as secondary metal resources. → The content and the total amount of metals in specific equipment are both important. → We categorized 21 EEE types from contents and total amounts of various metals. → Important equipment types as secondary resources were listed for each metal kind. → Collectability and possible collection systems of various EEE types were discussed. - Abstract: End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection

Effective public resource allocation to escape lock-in: the case of infrastructure-dependent vehicle technologies

NARCIS (Netherlands)

Vooren, A. van der; Alkemade, F.; Hekkert, M.P.

2012-01-01

A multi-stage technological substitution model of infrastructure-dependent vehicle technologies is developed. This is used to examine how the allocation of public, financial resources to RD&D support and infrastructure development affects the replacement of a locked-in vehicle technology by more

The impact parameter dependence of swift electron-matter interactions

International Nuclear Information System (INIS)

Ritchie, R.H.

1988-01-01

In quantal collision theories, momentum and energy are usually taken to be good quantal variables. Classical collision theory, on the other hand, uses position and time to describe interactions between a probe and a target. In modern physics one may wish to express quantal theories in terms of spacelike variables. For example, experiments are now common in which one measures, by means of a narrowly focused beam of swift electrons, the distribution in energy of losses experienced in a very small region of space. Also, in experiments with channeled ions, and in microdosimetry, one is interested in the spatial coherence of unlocalized excitations created by swift ions and electrons, and their ultimate localization through transfer of energy to, e.g., single-particle excitations. In this lecture the author describes work, done in part in collaboration with Professor Howie, on some aspects of the spatial dependence of inelastic interactions between a charged particle and a condensed matter target. 6 refs., 1 fig

Principles of formation of the content of an educational electronic resource on the basis of general and didactic patterns of learning

Directory of Open Access Journals (Sweden)

Ольга Юрьевна Заславская

2018-12-01

Full Text Available The article considers the influence of the development of technical means of teaching on the effectiveness of educational and methodical resources. Modern opportunities of information and communication technologies allow creating electronic educational resources that represent educational information that automates the learning process, provide information assistance, if necessary, collect and process statistical information on the degree of development of the content of the school material by schoolchildren, set an individual trajectory of learning, and so on. The main principle of data organization is the division of the training course into separate sections on the thematic elements and components of the learning process. General regularities include laws that encompass the entire didactic system, and in specific (particular cases, those whose actions extend to a separate component (aspect of the system. From the standpoint of the existence of three types of electronic training modules in the aggregate content of the electronic learning resource - information, control and module of practical classes - the principles of the formation of the electronic learning resource, in our opinion, should regulate all these components. Each of the certain principles is considered in the groups: scientific orientation, methodological orientation, systemic nature, accounting of interdisciplinary connections, fundamentalization, systematic and dosage sequence, rational use of study time, accessibility, minimization, operationalization of goals, unified identification diagnosis.

Relaxation oscillations induced by amplitude-dependent frequency in dissipative trapped electron mode turbulence

International Nuclear Information System (INIS)

Terry, P.W.; Ware, A.S.; Newman, D.E.

1994-01-01

A nonlinear frequency shift in dissipative trapped electron mode turbulence is shown to give rise to a relaxation oscillation in the saturated power density spectrum. A simple non-Markovian closure for the coupled evolution of ion momentum and electron density response is developed to describe the oscillations. From solutions of a nonlinear oscillator model based on the closure, it is found that the oscillation is driven by the growth rate, as modified by the amplitude-dependent frequency shift, with inertia provided by the memory of the growth rate of prior amplitudes. This memory arises from time-history integrals common to statistical closures. The memory associated with a finite time of energy transfer between coupled spectrum components does not sustain the oscillation in the simple model. Solutions of the model agree qualitatively with the time-dependent numerical solutions of the original dissipative trapped electron model, yielding oscillations with the proper phase relationship between the fluctuation energy and the frequency shift, the proper evolution of the wave number spectrum shape and particle flux, and a realistic period

Dose-dependent high-resolution electron ptychography

International Nuclear Information System (INIS)

D'Alfonso, A. J.; Allen, L. J.; Sawada, H.; Kirkland, A. I.

2016-01-01

Recent reports of electron ptychography at atomic resolution have ushered in a new era of coherent diffractive imaging in the context of electron microscopy. We report and discuss electron ptychography under variable electron dose conditions, exploring the prospects of an approach which has considerable potential for imaging where low dose is needed

Dependence of Whistler-mode Wave Induced Electron Precipitation on k-vector Direction.

Science.gov (United States)

Kulkarni, P.; Inan, U. S.; Bell, T. F.; Bortnik, J.

2007-12-01

Whistler-mode waves that are either spontaneously generated in-situ (i.e., chorus), or externally injected (lightning, VLF transmitters) are known to be responsible for the loss of radiation belt electrons. An important determinant in the quantification of this loss is the dependence of the cyclotron resonant pitch angle scattering on the initial wave normal angles of the driving waves. Inan et al. (U.S. Inan et al., Controlled precipitation of radiation belt electrons, Journal of Geophysical Research-Space Physics, 108 (A5), 1186, doi: 10.1029/2002JA009580, 2003.) suggested that the lifetime of > 1 MeV electrons in the inner radiation belts might be moderated by in situ injection of VLF whistler mode waves at frequencies of a few kHz. The formulation of Wang and Bell (T.N.C. Wang and T.F. Bell, Radiation resisitance of a short dipole immersed in a cold magnetoionic medium, Radio Science, 4(2), 167-177, February 1969) for an electric dipole antenna located in the inner magnetosphere established that most of the radiated power is concentrated in waves whose wave normal angles lie near the local resonance cone. Such waves, compared to those injected at less oblique initial wave normal angles, undergo several more magnetospheric reflections, persist in the magnetospheric cavity for longer periods of time, and resonate with electrons of higher energies. Accordingly, such waves may be highly effective in contributing to the loss of electrons from the inner belt and slot regions [Inan et al., 2006]. Nevertheless, it has been noted (Inan et al. [2006], Inan and Bell [1991] and Albert [1999]) that > 1 MeV electrons may not be effectively scattered by waves propagating with very high wave normal angles, due to the generally reduced gyroresonant diffusion coefficients for wave normals near the resonance cone. We use the Stanford 2D VLF raytracing program to determine the energetic electron pitch angle scattering and the precipitated flux signatures that would be detected for

Density dependence of electron mobility in the accumulation mode for fully depleted SOI films

Energy Technology Data Exchange (ETDEWEB)

Naumova, O. V., E-mail: naumova@isp.nsc.ru; Zaitseva, E. G.; Fomin, B. I.; Ilnitsky, M. A.; Popov, V. P. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2015-10-15

The electron mobility µ{sub eff} in the accumulation mode is investigated for undepleted and fully depleted double-gate n{sup +}–n–n{sup +} silicon-on-insulator (SOI) metal–oxide–semiconductor field-effect transistors (MOSFET). To determine the range of possible values of the mobility and the dominant scattering mechanisms in thin-film structures, it is proposed that the field dependence of the mobility µ{sub eff} be replaced with the dependence on the density N{sub e} of induced charge carriers. It is shown that the dependences µ{sub eff}(N{sub e}) can be approximated by the power functions µ{sub eff}(N{sub e}) ∝ N{sub e}{sup -n}, where the exponent n is determined by the chargecarrier scattering mechanism as in the mobility field dependence. The values of the exponent n in the dependences µ{sub eff}(N{sub e}) are determined when the SOI-film mode near one of its surfaces varies from inversion to accumulation. The obtained results are explained from the viewpoint of the electron-density redistribution over the SOI-film thickness and changes in the scattering mechanisms.

Temperature Dependent Electron Transport Properties of Gold Nanoparticles and Composites: Scanning Tunneling Spectroscopy Investigations.

Science.gov (United States)

Patil, Sumati; Datar, Suwarna; Dharmadhikari, C V

2018-03-01

Scanning tunneling spectroscopy (STS) is used for investigating variations in electronic properties of gold nanoparticles (AuNPs) and its composite with urethane-methacrylate comb polymer (UMCP) as function of temperature. Films are prepared by drop casting AuNPs and UMCP in desired manner on silicon substrates. Samples are further analyzed for morphology under scanning electron microscopy (SEM) and atomic force microscopy (AFM). STS measurements performed in temperature range of 33 °C to 142 °C show systematic variation in current versus voltage (I-V) curves, exhibiting semiconducting to metallic transition/Schottky behavior for different samples, depending upon preparation method and as function of temperature. During current versus time (I-t) measurement for AuNPs, random telegraphic noise is observed at room temperature. Random switching of tunneling current between two discrete levels is observed for this sample. Power spectra derived from I-t show 1/f2 dependence. Statistical analysis of fluctuations shows exponential behavior with time width τ ≈ 7 ms. Local density of states (LDOS) plots derived from I-V curves of each sample show systematic shift in valance/conduction band edge towards/away from Fermi level, with respect to increase in temperature. Schottky emission is best fitted electron emission mechanism for all samples over certain range of bias voltage. Schottky plots are used to calculate barrier heights and temperature dependent measurements helped in measuring activation energies for electron transport in all samples.

Reentrant behavior in the superconducting phase-dependent resistance of a disordered two-dimensional electron gas

NARCIS (Netherlands)

den Hartog, S.G.; Wees, B.J.van; Klapwijk, T.M; Nazarov, Y.V.; Borghs, G.

1997-01-01

We have investigated the bias-voltage dependence of the phase-dependent differential resistance of a disordered T-shaped two-dimensional electron gas coupled to two superconducting terminals. The resistance oscillations first increase upon lowering the energy. For bias voltages below the Thouless

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-05-17

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

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

The Synthesis of the Hierarchical Structure of Information Resources for Management of Electronic Commerce Entities

Directory of Open Access Journals (Sweden)

Krutova Anzhelika S.

2017-06-01

Full Text Available The aim of the article is to develop the theoretical bases for the classification and coding of economic information and the scientific justification of the content of information resources of an electronic commerce enterprise. The essence of information resources for management of electronic business entities is investigated. It is proved that the organization of accounting in e-commerce systems is advisable to be built on the basis of two circuits: accounting for financial flows and accounting associated with transformation of business factors in products and services as a result of production activities. There presented a sequence of accounting organization that allows to combine the both circuits in a single information system, which provides a possibility for the integrated replenishment and distributed simultaneous use of the e-commerce system by all groups of users. It is proved that the guarantee of efficient activity of the information management system of electronic commerce entities is a proper systematization of the aggregate of information resources on economic facts and operations of an enterprise in accordance with the management tasks by building the hierarchy of accounting nomenclatures. It is suggested to understand nomenclature as an objective, primary information aggregate concerning a certain fact of the economic activity of an enterprise, which is characterized by minimum requisites, is entered into the database of the information system and is to be reflected in the accounting system. It is proposed to build a database of e-commerce systems as a part of directories (constants, personnel, goods / products, suppliers, buyers and the hierarchy of accounting nomenclatures. The package of documents regulating the organization of accounting at an enterprise should include: the provision on the accounting services, the order on the accounting policy, the job descriptions, the schedules of information exchange, the report card and

Constitutive NADPH-dependent electron transferase activity of the Nox4 dehydrogenase domain.

Science.gov (United States)

Nisimoto, Yukio; Jackson, Heather M; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J David

2010-03-23

NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47(phox) and p67(phox) and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K(m) for NADPH of 55 +/- 10 microM. The concentration of Nox4 in cell lysates was estimated using Western blotting and allowed calculation of a turnover of approximately 200 mol of H(2)O(2) min(-1) (mol of Nox4)(-1). A chimeric protein (Nox2/4) consisting of the Nox2 transmembrane (TM) domain and the Nox4 dehydrogenase (DH) domain showed H(2)O(2) production in the absence of cytosolic regulatory subunits. In contrast, chimera Nox4/2, consisting of the Nox4 TM and Nox2 DH domains, exhibited PMA-dependent activation that required coexpression of regulatory subunits. Nox DH domains from several Nox isoforms were purified and evaluated for their electron transferase activities. Nox1 DH, Nox2 DH, and Nox5 DH domains exhibited barely detectable activities toward artificial electron acceptors, while the Nox4 DH domain exhibited significant rates of reduction of cytochrome c (160 min(-1), largely superoxide dismutase-independent), ferricyanide (470 min(-1)), and other electron acceptors (artificial dyes and cytochrome b(5)). Rates were similar to those observed for H(2)O(2) production by the Nox4 holoenzyme in cell lysates. The activity required added FAD and was seen with NADPH but not NADH. These results indicate that the Nox4 DH domain exists in an intrinsically activated state and that electron transfer from NADPH to FAD is likely to be rate-limiting in the NADPH-dependent reduction of oxygen by holo-Nox4.

Effect of the δ-potential on spin-dependent electron tunneling in double barrier semiconductor heterostructure

Science.gov (United States)

Chandrasekar, L. Bruno; Gnanasekar, K.; Karunakaran, M.

2018-06-01

The effect of δ-potential was studied in GaAs/Ga0.6Al0·4As double barrier heterostructure with Dresselhaus spin-orbit interaction. The role of barrier height and position of the δ- potential in the well region was analysed on spin-dependent electron tunneling using transfer matrix method. The spin-separation between spin-resonances on energy scale depends on both height and position of the δ- potential, whereas the tunneling life time of electrons highly influenced by the position of the δ- potential and not on the height. These results might be helpful for the fabrication of spin-filters.

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2015-06-16

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

Energy and orientation dependence of electron-irradiation-induced defects in InP

International Nuclear Information System (INIS)

Sibille, A.; Suski, J.; LeRoux, G.

1984-01-01

The concentration of several electron-irradiation-induced deep defect levels in InP has been measured by deep-level transient spectroscopy (DLTS) as a function of electron energy. The dominant centers exhibit a threshold at about 100 keV, which clearly points to a primary production event by electron--phosphorus-atom collision. This unambiguous determination allowed a test of the recently proposed orientation dependence technique to find the nature of the sublattice involved in the collision process for III-V compounds. A good quantitative agreement is obtained with a hard-sphere model for secondary collisions if disorientation of the beam in the sample is taken into account. Other traps exhibit higher thresholds which correspond either to indium-atom displacements or to the involvement of secondary collisions in the production event

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

Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

Science.gov (United States)

Goodfellow, L M

2009-06-01

A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

Knowledge and Natural Resources

DEFF Research Database (Denmark)

Bertelsen, Rasmus Gjedssø; Justinussen, Jens Christian Svabo

2016-01-01

Arctic economies are generally natural resource based economies, whether they are indigenous economies largely dependent on living on the land or industrialized economies depending on marine resources, mineral resources or fossil or renewable energy resources. However, the central role of knowledge...

Communication: On the calculation of time-dependent electron flux within the Born-Oppenheimer approximation: A flux-flux reflection principle

Science.gov (United States)

Albert, Julian; Hader, Kilian; Engel, Volker

2017-12-01

It is commonly assumed that the time-dependent electron flux calculated within the Born-Oppenheimer (BO) approximation vanishes. This is not necessarily true if the flux is directly determined from the continuity equation obeyed by the electron density. This finding is illustrated for a one-dimensional model of coupled electronic-nuclear dynamics. There, the BO flux is in perfect agreement with the one calculated from a solution of the time-dependent Schrödinger equation for the coupled motion. A reflection principle is derived where the nuclear BO flux is mapped onto the electronic flux.

Temperature-dependent surface structure, composition, and electronic properties of the clean SrTiO3(111) crystal face: Low-energy-electron diffraction, Auger-electron spectroscopy, electron energy loss, and ultraviolet-photoelectron spectroscopy studies

International Nuclear Information System (INIS)

Lo, W.J.; Somorjai, G.A.

1978-01-01

Low-energy-electron diffraction, Auger-electron spectroscopy, electron-energy-loss, and ultraviolet-photoelectron spectroscopies were used to study the structure, composition, and electron energy distribution of a clean single-crystal (111) face of strontium titanate (perovskite). The dependence of the surface chemical composition on the temperature has been observed along with corresponding changes in the surface electronic properties. High-temperature Ar-ion bombardment causes an irreversible change in the surface structure, stoichiometry, and electron energy distribution. In contrast to the TiO 2 surface, there are always significant concentrations of Ti 3+ in an annealed ordered SrTiO 3 (111) surface. This stable active Ti 3+ monolayer on top of a substrate with large surface dipole potential makes SrTiO 3 superior to TiO 2 when used as a photoanode in the photoelectrochemical cell

Gafchromic EBT3 film dosimetry in electron beams — energy dependence and improved film read‐out

Science.gov (United States)

Ojala, Jarkko; Kaijaluoto, Sampsa; Jokelainen, Ilkka; Kosunen, Antti

2016-01-01

For megavoltage photon radiation, the fundamental dosimetry characteristics of Gafchromic EBT3 film were determined in  60Co gamma ray beam with addition of experimental and Monte Carlo (MC)‐simulated energy dependence of the film for 6 MV photon beam and 6 MeV, 9 MeV, 12 MeV, and 16 MeV electron beams in water phantom. For the film read‐out, two phase correction of scanner sensitivity was applied: a matrix correction for scanning area and dose‐dependent correction by iterative procedure. With these corrections, the uniformity of response can be improved to be within ±50 pixel values (PVs). To improve the read‐out accuracy, a procedure with flipped film orientations was established. With the method, scanner uniformity can be improved further and dust particles, scratches and/or dirt on scanner glass can be detected and eliminated. Responses from red and green channels were averaged for read‐out, which decreased the effect of noise present in values from separate channels. Since the signal level with the blue channel is considerably lower than with other channels, the signal variation due to different perturbation effects increases the noise level so that the blue channel is not recommended to be used for dose determination. However, the blue channel can be used for the detection of emulsion thickness variations for film quality evaluations with unexposed films. With electron beams ranging from 6 MeV to 16 MeV and at reference measurement conditions in water, the energy dependence of the EBT3 film is uniform within 0.5%, with uncertainties close to 1.6% (k=2). Including 6 MV photon beam and the electron beams mentioned, the energy dependence is within 1.1%. No notable differences were found between the experimental and MC‐simulated responses, indicating negligible change in intrinsic energy dependence of the EBT3 film for 6 MV photon beam and 6 MeV–16 MeV electron beams. Based on the dosimetric characteristics of the EBT3 film, the read�

Resonant spin-flavor conversion of supernova neutrinos: Dependence on electron mole fraction

International Nuclear Information System (INIS)

Yoshida, Takashi; Takamura, Akira; Kimura, Keiichi; Yokomakura, Hidekazu; Kawagoe, Shio; Kajino, Toshitaka

2009-01-01

Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Y e is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds 0.5 in several seconds after the core collapse. When a higher resonance of the RSF conversion is located in the innermost region, flavor change of the neutrinos strongly depends on the sign of 1-2Y e . At an adiabatic high RSF resonance the flavor conversion of ν e ↔ν μ,τ occurs in Y e e >0.5 and inverted mass hierarchy. In other cases of Y e values and mass hierarchies, the conversion of ν e ↔ν μ,τ occurs. The final ν e spectrum is evaluated in the cases of Y e e >0.5 taking account of the RSF conversion. Based on the obtained result, time variation of the event number ratios of low ν e energy to high ν e energy is discussed. In normal mass hierarchy, an enhancement of the event ratio should be seen in the period when the electron fraction in the innermost region exceeds 0.5. In inverted mass hierarchy, on the other hand, a dip of the event ratio should be observed. Therefore, the time variation of the event number ratio is useful to investigate the effect of the RSF conversion.

Library resources on the Internet

Science.gov (United States)

Buchanan, Nancy L.

1995-07-01

Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

Temperature dependence of electronic transport property in ferroelectric polymer films

Energy Technology Data Exchange (ETDEWEB)

Zhao, X.L.; Wang, J.L., E-mail: jlwang@mail.sitp.ac.cn; Tian, B.B.; Liu, B.L.; Zou, Y.H.; Wang, X.D.; Sun, S.; Sun, J.L., E-mail: jlsun@mail.sitp.ac.cn; Meng, X.J.; Chu, J.H.

2014-10-15

Highlights: • The ferroelectric polymer was fabricated by Langmuir–Blodgett method. • The electrons as the dominant injected carrier were conformed in the ferroelectric polymer films. • The leakage current conduction mechanisms in ferroelectric polymer were investigated. - Abstract: The leakage current mechanism of ferroelectric copolymer of polyvinylidene fluoride with trifluoroethylene prepared by Langmuir–Blodgett was investigated in the temperature range from 100 K to 350 K. The electron as the dominant injected carrier was observed in the ferroelectric copolymer films. The transport mechanisms in copolymer strongly depend on the temperature and applied voltage. From 100 K to 200 K, Schottky emission dominates the conduction. With temperature increasing, the Frenkel–Poole emission instead of the Schottky emission to conduct the carrier transport. When the temperature gets to 260 K, the leakage current becomes independent of temperature, and the space charge limited current conduction was observed.

Spin-dependent hot electron transport and nano-scale magnetic imaging of metal/Si structures

International Nuclear Information System (INIS)

Kaidatzis, A.

2008-10-01

In this work, we experimentally study spin-dependent hot electron transport through metallic multilayers (ML), containing single magnetic layers or 'spin-valve' (SV) tri layers. For this purpose, we have set up a ballistic electron emission microscope (BEEM), a three terminal extension of scanning tunnelling microscopy on metal/semiconductor structures. The implementation of the BEEM requirements into the sample fabrication is described in detail. Using BEEM, the hot electron transmission through the ML's was systematically measured in the energy range 1-2 eV above the Fermi level. By varying the magnetic layer thickness, the spin-dependent hot electron attenuation lengths were deduced. For the materials studied (Co and NiFe), they were compared to calculations and other determinations in the literature. For sub-monolayer thickness, a non uniform morphology was observed, with large transmission variations over sub-nano-metric distances. This effect is not yet fully understood. In the imaging mode, the magnetic configurations of SV's were studied under field, focusing on 360 degrees domain walls in Co layers. The effects of the applied field intensity and direction on the DW structure were studied. The results were compared quantitatively to micro-magnetic calculations, with an excellent agreement. From this, it can be shown that the BEEM magnetic resolution is better than 50 nm. (author)

ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

Directory of Open Access Journals (Sweden)

Maria D. Tukalo

2013-09-01

Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

Selection and Evaluation of Electronic Resources

Directory of Open Access Journals (Sweden)

Doğan Atılgan

2013-11-01

Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined.

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.)

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-01-01

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-05-03

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

The level of the usage of the human resource information system and electronic recruitment in Croatian companies

Directory of Open Access Journals (Sweden)

Snježana Pivac

2014-12-01

Full Text Available Performing business according to contemporary requirements influences companies for continuous usage of modern managerial tools, such as a human resource information system (HRIS and electronic recruitment (ER. Human resources have been recognised as curtail resources and the main source of a competitive advantage in creation of successful business performance. In order to attract and select the top employees, companies use quality information software for attracting internal ones, and electronic recruitment for attracting the best possible external candidates. The main aim of this paper is to research the level of the usage of HRIS and ER within medium-size and large Croatian companies. Moreover, the additional aim of this paper is to evaluate the relationship among the usage of these modern managerial tools and the overall success of human resource management within these companies. For the purpose of this paper, primary and secondary research has been conducted in order to reveal the level of the usage of HRIS and ER as well as the overall success of human resource management in Croatian companies. The companies’ classification (HRIS and ER is done by using the non-hierarchical k-means cluster method as well as the nonparametric Kruskal Wallis test. Further, the companies are ranked by the multicriteria PROMETHEE method. Relevant nonparametric tests are used for testing the overall companies’ HRM. Finally, binary logistic regression is estimated, relating binary variable HRM and HRIS development. After detailed research, it can be concluded that large Croatian companies apply HRIS in majority (with a positive relation to HRM performance, but still require certain degrees of its development.

The electronic encapsulation of knowledge in hydraulics, hydrology and water resources

Science.gov (United States)

Abbott, Michael B.

The rapidly developing practice of encapsulating knowledge in electronic media is shown to lead necessarily to the restructuring of the knowledge itself. The consequences of this for hydraulics, hydrology and more general water-resources management are investigated in particular relation to current process-simulation, real-time control and advice-serving systems. The generic properties of the electronic knowledge encapsulator are described, and attention is drawn to the manner in which knowledge 'goes into hiding' through encapsulation. This property is traced in the simple situations of pure mathesis and in the more complex situations of taxinomia using one example each from hydraulics and hydrology. The consequences for systems architectures are explained, pointing to the need for multi-agent architectures for ecological modelling and for more general hydroinformatics systems also. The relevance of these developments is indicated by reference to ongoing projects in which they are currently being realised. In conclusion, some more general epistemological aspects are considered within the same context. As this contribution is so much concerned with the processes of signification and communication, it has been partly shaped by the theory of semiotics, as popularised by Eco ( A Theory of Semiotics, Indiana University, Bloomington, 1977).

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.

Mapping momentum-dependent electron-phonon coupling and nonequilibrium phonon dynamics with ultrafast electron diffuse scattering

Science.gov (United States)

Stern, Mark J.; René de Cotret, Laurent P.; Otto, Martin R.; Chatelain, Robert P.; Boisvert, Jean-Philippe; Sutton, Mark; Siwick, Bradley J.

2018-04-01

Despite their fundamental role in determining material properties, detailed momentum-dependent information on the strength of electron-phonon and phonon-phonon coupling (EPC and PPC, respectively) across the entire Brillouin zone has remained elusive. Here we demonstrate that ultrafast electron diffuse scattering (UEDS) directly provides such information. By exploiting symmetry-based selection rules and time resolution, scattering from different phonon branches can be distinguished even without energy resolution. Using graphite as a model system, we show that UEDS patterns map the relative EPC and PPC strength through their profound sensitivity to photoinduced changes in phonon populations. We measure strong EPC to the K -point TO phonon of A1' symmetry (K -A1' ) and along the entire TO branch between Γ -K , not only to the Γ -E2 g phonon. We also determine that the subsequent phonon relaxation of these strongly coupled optical phonons involve three stages: decay via several identifiable channels to TA and LA phonons (1 -2 ps), intraband thermalization of the non-equilibrium TA/LA phonon populations (30 -40 ps) and interband relaxation of the TA/LA modes (115 ps). Combining UEDS with ultrafast angle-resolved photoelectron spectroscopy will yield a complete picture of the dynamics within and between electron and phonon subsystems, helping to unravel complex phases in which the intertwined nature of these systems has a strong influence on emergent properties.

A dependência pela prática de exercícios físicos e o uso de recursos ergogênicos = Physical exercise dependence and the use of ergogenic resources

Directory of Open Access Journals (Sweden)

José Luiz Lopes Vieira

2010-01-01

Full Text Available Objetivou-se Investigar a ocorrência de dependência por exercícios físicos quanto às características de praticantes de musculação e ginástica em academias, como uso de recursos ergogênicos, sexo e índice de massa corporal. Participaram do estudo 80 sujeitos (27,12 ± 6,60 anos, praticantes de ginástica e/ou musculação em academias, de ambos os sexos. Utilizou-se a Escala de Dependência por Exercícios Físicos, a listagem do tipo de suplemento alimentar utilizado como recurso ergogênico e o Índice de Massa Corporal – IMC (Kg/cm². A análise estatística foi realizada por meio da correlação de Spearman e o teste de Wilcoxon (p The aim of this study is to investigate the occurrence of physical exercise dependence in regards to the characteristics of participants in weight training and exercises at gyms, such as the use ofergogenic resources, gender and body mass index. Eighty subjects (27.12 ± 6.60 years from both genders took part in the study, all of whom practiced gymnastics and/or weight training in gyms. The study utilized the Exercise Dependence Scale, a check list of the kinds of nutritional supplementation used as ergogenic resources, and the Body Mass Index – BMI (Kg cm-². Statistical analysis was performed using Spearman's correlation and the Wilcoxon test (p < 0.05. The results showed that there was no statistically significant difference between physical exercise dependence in men (5.14 ± 1.28 and women (5.60 ± 1.45. The body mass index did not show statistically significant correlation with the scores of dependency, either. However, dependentmen showed high prevalence of use of ergogenic resources (63.63%, p = 0.01, while for dependent women there were no statistically significant results. The body mass index does not relate to the scores of exercise dependence. However, even with a normal BMI, the use of ergogenic resources presents high prevalence among dependent men. As a result, there is evidence that

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

Dependence of ion-electron emission from clean metals on the incidence angle of the projectile

International Nuclear Information System (INIS)

Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

1981-01-01

We have studied the dependence of electron yields γ from clean Cu and Au surfaces on the incidence angle theta of 5--50-keV He + , Ar + , and Xe + projectiles, in the angular range 0--80 0 , and under ultrahigh-vacuum conditions. We have found that, at small angles, γproportionalsec/sup f/theta, with f generally different from unity. For Xe + on Cu, γ(theta) presents an energy-dependence maximum, similar to that obtained for sputtering. The results are explained in terms of the anisotropy of the electron cascade in the solid, the depth distribution of the inelastic energy deposited by the projectile and by rapidly recoiling target atoms in the near-surface region of the solid

Comprehensive z-dependent measurements of electron-beam microbunching using COTR in a saturated SASE FEL

CERN Document Server

Lumpkin, Alex H; Lewellen, J W; Berg, W; Biedron, S G; Borland, M; Chae, Y; Erdmann, M; Huang, Z; Kim, K J; Li, Y; Milton, S V; Moog, E; Rule, D W; Sajaev, Vadim; Yang, B X

2002-01-01

We report the initial, comprehensive set of z-dependent measurements of electron-beam microbunching using coherent optical transition radiation (Cot) in a saturated self-amplified spontaneous emission (SASE) free-electron laser (FEL) experiment. In this case the FEL was operated near 530 nm using an enhanced facility including a bunch-compressed photocathode gun electron beam, linac, and 21.6 m of undulator length. The longitudinal microbunching was tracked by inserting a metal foil and mirror after each of the nine 2.4-m-long undulators and measuring the visible COTR spectra, intensity, angular, distribution, and spot size. We observed for the first time the z-dependent transition of the COTR spectra from simple lines to complex structure/sidebands near saturation. We also observed the change in the microbunching fraction after saturation, multiple fringes in the COTR interferogram that are consistent with involvement of a smaller core of the e-beam transverse distribution, and the second harmonic content of...

Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

Science.gov (United States)

Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

2015-10-20

Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

Time-dependent restricted-active-space self-consistent eld theory: Formulation and application to laser-driven many-electron dynamics

DEFF Research Database (Denmark)

Miyagi, Haruhide; Madsen, Lars Bojer

We have developed a new theoretical framework for time-dependent many-electron problems named time-dependent restricted-active-space self-consistent field (TD-RASSCF) theory. The theory generalizes the multicongurational time-dependent Hartree-Fock (MCTDHF) theory by truncating the expansion...

Time-dependent radiolytic yields at room temperature and temperature-dependent absorption spectra of the solvated electrons in polyols

International Nuclear Information System (INIS)

Lin Mingzhang; Mostafavi, M.; Lampre, I.; Muroya, Y.; Katsumura, Y.

2007-01-01

The molar extinction coefficients at the absorption maximum of the solvated electron spectrum have been evaluated to be 900, 970, and 1000 mol -1 ·m 2 for 1,2-ethanediol (12ED), 1,2-propanediol (12PD), and 1,3-propanediol (13PD), respectively. These values are two-third or three-fourth of the value usually reported in the published report. Picosecond pulse radiolysis studies have aided in depicting the radiolytic yield of the solvated electron in these solvents as a function of time from picosecond to microsecond. The radiolytic yield in these viscous solvents is found to be strongly different from that of the water solution. The temperature dependent absorption spectra of the solvated electron in 12ED, 12PD, and 13PD have been also investigated. In all the three solvents, the optical spectra shift to the red with increasing temperature. While the shape of the spectra does not change in 13PD, a widening on the blue side of the absorption band is observed in 12ED and 12PD at elevated temperatures. (authors)

Bias dependent charge trapping in MOSFETs during 1 and 6 MeV electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Shinde, N.S. [Department of Chemical Engineering, Mie University, 5148507 (Japan); Kulkarni, V.R.; Mathakari, N.L.; Bhoraskar, V.N. [Department of Physics, Univeristy of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, Univeristy of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

2008-06-15

To study irradiation-induced charge trapping in SiO{sub 2} and around the SiO{sub 2}-Si interface, depletion n-MOSFETs (metal-oxide-semiconductor field effect transistor) were used. The devices were gate biased during 1 and 6 MeV pulsed electron irradiation. The I{sub D}-V{sub DS} (drain current versus drain voltage) and I{sub D}-V{sub GS} (drain current versus gate voltage) characteristics were measured before and after irradiation. The shift in threshold voltage {delta}V{sub T} (difference in threshold voltage V{sub T} before and after irradiation) exhibited trends depending on the applied gate bias during 1 MeV electron irradiation. This behavior can be associated to the contribution of irradiation-induced negative charge {delta}N{sub IT} buildup around the SiO{sub 2}-Si interface to {delta}V{sub T}, which is sensitive to the electron tunneling from the substrates. However, only weak gate bias dependence was observed in 6 MeV electron irradiated devices. Independent of the energy loss and applied bias, the positive oxide trapped charge {delta}N{sub OT} is marginal and can be associated to thin and good quality of SiO{sub 2}. These results are explained using screening of free and acceptor states by the applied bias during irradiation, thereby reducing the total irradiation-induced charges.

Dependence of electronic properties of germanium on the in-plane biaxial tensile strains

Energy Technology Data Exchange (ETDEWEB)

Yang, C.H. [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876 (China); Yu, Z.Y., E-mail: yuzhongyuan30@gmail.com [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876 (China); Liu, Y.M.; Lu, P.F. [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876 (China); Gao, T. [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Li, M.; Manzoor, S. [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876 (China)

2013-10-15

The hybrid HSE06 functional with the spin–orbit coupling effects is used to calculate the habituation of the electronic properties of Ge on the (0 0 1), (1 1 1), (1 0 1) in-plane biaxial tensile strains (IPBTSs). Our motivation is to explore the nature of electronic properties of tensile-strained Ge on different substrate orientations. The calculated results demonstrate that one of the most effective and practical approaches for transforming Ge into a direct transition semiconductor is to introduce (0 0 1) IPBTS to Ge. At 2.3% (0 0 1) IPBTS, Ge becomes a direct bandgap semiconductor with 0.53 eV band gap, in good agreement with the previous theoretical and experimental results. We find that the (1 1 1) and (1 0 1) IPBTSs are not efficient since the shear strain and inner displacement of atoms introduced by them quickly decrease the indirect gap of Ge. By investigating the dependence of valence band spin–orbit splitting on strain, we prove that the dependency relationship and the coupled ways between the valence-band states of tensile-strained Ge are closely related to the symmetry of strain tensor, i.e., the symmetry of the substrate orientation. The first- and second-order coefficients describing the dependence of indirect gap, direct gap, the valence band spin–orbit coupling splitting, and heavy-hole–light-hole splitting of Ge on IPBTSs have been obtained by the least squares polynomial fitting. These coefficients are significant to quantitatively modulate the electronic properties of Ge by tensile strain and design tensile-strained Ge devices by semiconductor epitaxial technique.

Dependence of ion-electron emission from clean metals on the incidence angle of the projectile

Energy Technology Data Exchange (ETDEWEB)

Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

1981-10-15

We have studied the dependence of electron yields ..gamma.. from clean Cu and Au surfaces on the incidence angle theta of 5--50-keV He/sup +/, Ar/sup +/, and Xe/sup +/ projectiles, in the angular range 0--80 /sup 0/, and under ultrahigh-vacuum conditions. We have found that, at small angles, ..gamma..proportionalsec/sup f/theta, with f generally different from unity. For Xe/sup +/ on Cu, ..gamma..(theta) presents an energy-dependence maximum, similar to that obtained for sputtering. The results are explained in terms of the anisotropy of the electron cascade in the solid, the depth distribution of the inelastic energy deposited by the projectile and by rapidly recoiling target atoms in the near-surface region of the solid.

Temperature and intensity dependence of the performance of an electron-irradiated (AlGa)As/GaAs solar cell

Science.gov (United States)

Swartz, C. K.; Hart, R. E., Jr.

1979-01-01

The performance of a Hughes, liquid-phase epitaxial 2 centimeter-by-2 centimeter, (AlGa)As/GaAs solar cell was measured before and after irradiations with 1 MeV electrons to fluences of 1 x 10 to the 16th power electrons/sq cm. The temperature dependence of performance was measured over the temperature range 135 to 415 K at each fluence level. In addition, temperature dependences were measured at five intensity levels from 137 to 2.57 mW/sq cm before irradiation and after a fluence of 1 x 10 to the 16th power electrons/sq cm. For the intermediate fluences, performance was measured as a function of intensity at 298 K only.

The magnetism and spin-dependent electronic transport properties of boron nitride atomic chains

International Nuclear Information System (INIS)

An, Yipeng; Zhang, Mengjun; Wang, Tianxing; Jiao, Zhaoyong; Wu, Dapeng; Fu, Zhaoming; Wang, Kun

2016-01-01

Very recently, boron nitride atomic chains were successively prepared and observed in experiments [O. Cretu et al., ACS Nano 8, 11950 (2015)]. Herein, using a first-principles technique, we study the magnetism and spin-dependent electronic transport properties of three types of BN atomic chains whose magnetic moment is 1 μ B for B n N n−1 , 2 μ B for B n N n , and 3 μ B for B n N n+1 type atomic chains, respectively. The spin-dependent electronic transport results demonstrate that the short B n N n+1 chain presents an obvious spin-filtering effect with high spin polarization ratio (>90%) under low bias voltages. Yet, this spin-filtering effect does not occur for long B n N n+1 chains under high bias voltages and other types of BN atomic chains (B n N n−1 and B n N n ). The proposed short B n N n+1 chain is predicted to be an effective low-bias spin filters. Moreover, the length-conductance relationships of these BN atomic chains were also studied.

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.

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.

Electron-induced desorption of europium atoms from oxidized tungsten surface: concentration dependence of low-energy peak

CERN Document Server

Davydov, S Y

2002-01-01

One discusses nature of electron induced desorption of Eu sup 0 europium atoms under E sub e irradiating electron low-energies (approx 30 eV) and peculiarities of yield dependence of Eu sup 0 atoms on their concentration at oxidized tungsten surface. Primary act of vacancy origination in europium adatom inner 5p-shell turned to be the determining stage. Evaluations have shown that just the first of two possible scenarios of ionization (electron intra-atomic to Eu adatom external quasi-level or realise of knocked out electron into vacuum) leads to Eu sup 0 desorption. One determined concentration threshold for yield of Eu sup 0 atoms

Energy dependence of solar-neutrino--electron scattering as a test of neutral currents

International Nuclear Information System (INIS)

Kwong, W.; Rosen, S.P.

1992-01-01

The energy dependence of ν-e scattering of solar neutrinos is investigated in the framework of neutrino oscillations and the nonadiabatic Mikheyev-Smirnov-Wolfenstein effect. It is shown that, with sufficient data, it will be possible to establish unambiguously whether neutrino oscillations are actually occurring and whether the electron neutrino oscillates into active or inactive (sterile) neutrino flavors

Using mobile electronic devices to deliver educational resources in developing countries.

Science.gov (United States)

Mazal, Jonathan Robert; Ludwig, Rebecca

2015-01-01

Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

Scale Dependence of Female Ungulate Reproductive Success in Relation to Nutritional Condition, Resource Selection and Multi-Predator Avoidance.

Directory of Open Access Journals (Sweden)

Jared F Duquette

Full Text Available Female ungulate reproductive success is dependent on the survival of their young, and affected by maternal resource selection, predator avoidance, and nutritional condition. However, potential hierarchical effects of these factors on reproductive success are largely unknown, especially in multi-predator landscapes. We expanded on previous research of neonatal white-tailed deer (Odocoileus virginianus daily survival within home ranges to assess if resource use, integrated risk of 4 mammalian predators, maternal nutrition, winter severity, hiding cover, or interactions among these variables best explained landscape scale variation in daily or seasonal survival during the post-partum period. We hypothesized that reproductive success would be limited greater by predation risk at coarser spatiotemporal scales, but habitat use at finer scales. An additive model of daily non-ideal resource use and maternal nutrition explained the most (69% variation in survival; though 65% of this variation was related to maternal nutrition. Strong support of maternal nutrition across spatiotemporal scales did not fully support our hypothesis, but suggested reproductive success was related to dam behaviors directed at increasing nutritional condition. These behaviors were especially important following severe winters, when dams produced smaller fawns with less probability of survival. To increase nutritional condition and decrease wolf (Canis lupus predation risk, dams appeared to place fawns in isolated deciduous forest patches near roads. However, this resource selection represented non-ideal resources for fawns, which had greater predation risk that led to additive mortalities beyond those related to resources alone. Although the reproductive strategy of dams resulted in greater predation of fawns from alternative predators, it likely improved the life-long reproductive success of dams, as many were late-aged (>10 years old and could have produced multiple litters

Success criteria for electronic medical record implementations in low-resource settings: a systematic review.

Science.gov (United States)

Fritz, Fleur; Tilahun, Binyam; Dugas, Martin

2015-03-01

Electronic medical record (EMR) systems have the potential of supporting clinical work by providing the right information at the right time to the right people and thus make efficient use of resources. This is especially important in low-resource settings where reliable data are also needed to support public health and local supporting organizations. In this systematic literature review, our objectives are to identify and collect literature about success criteria of EMR implementations in low-resource settings and to summarize them into recommendations. Our search strategy relied on PubMed queries and manual bibliography reviews. Studies were included if EMR implementations in low-resource settings were described. The extracted success criteria and measurements were summarized into 7 categories: ethical, financial, functionality, organizational, political, technical, and training. We collected 381 success criteria with 229 measurements from 47 articles out of 223 articles. Most papers were evaluations or lessons learned from African countries, published from 1999 to 2013. Almost half of the EMR systems served a specific disease area like human immunodeficiency virus (HIV). The majority of criteria that were reported dealt with the functionality, followed by organizational issues, and technical infrastructures. Sufficient training and skilled personnel were mentioned in roughly 10%. Political, ethical, and financial considerations did not play a predominant role. More evaluations based on reliable frameworks are needed. Highly reliable data handling methods, human resources and effective project management, as well as technical architecture and infrastructure are all key factors for successful EMR implementation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inter-dependence not Over-dependence: Reducing Urban Transport Energy Dependence

Energy Technology Data Exchange (ETDEWEB)

Saunders, Michael James; Rodrigues da Silva, Antonio Nelson

2007-07-01

A major issue of concern in today's world is urban transport energy dependence and energy supply security. In an energy inter-dependent world, energy over-dependence brings risks to urban transport systems. Many urban areas are over-dependent on finite petroleum resources for transport. New technology and the development and integration of renewable resources into transport energy systems may reduce some of the current transport energy dependence of urban areas. However, the most effective means of reducing energy dependence is to first design urban areas for this condition. An urban policy framework is proposed that requires transport energy dependence to be measured and controlled in the urban development process. A new tool has been created for this purpose, the Transport Energy Specification (TES), which measures transport energy dependence of urban areas. This creates the possibility for cities to regulate urban development with respect to energy dependence. Trial assessments were performed in Germany, New Zealand and Brazil; initial analysis by transport and government professionals shows promise of this tool being included into urban policy. The TES combined with a regulatory framework has the potential to significantly reduce transport energy consumption and dependence in urban areas in the future. (auth)

Modelling Oil‑Sector Dependency of Tax Revenues in a Resource Rich Country: Evidence from Azerbaijan

Directory of Open Access Journals (Sweden)

Akif Musayev

2017-01-01

Full Text Available Forecasting tax revenues is an important issue in budget planning. As a resource rich country, Azerbaijan’s budget revenues is severely depend on oil price and production levels. This study investigates oil sector dependency of state budget tax revenues in case of Azerbaijan by employing FMOLS, DOLS and CCR cointegration methods for the period of 2000Q1 – 2015Q2. Empirical results indicate statistically and economically significant positive long‑run impact of both oil related factors on tax revenues. Considering current fiscal challenges in the country, research findings are very useful for policy purposes and fills the gap in the literature by drawing mechanism of the association and estimating the relationship empirically.

Atomistic simulation of femtosecond laser pulse interactions with a copper film: Effect of dependency of penetration depth and reflectivity on electron temperature

Science.gov (United States)

Amouye Foumani, A.; Niknam, A. R.

2018-01-01

The response of copper films to irradiation with laser pulses of fluences in the range of 100-6000 J/m2 is simulated by using a modified combination of a two-temperature model (TTM) and molecular dynamics (MD). In this model, the dependency of the pulse penetration depth and the reflectivity of the target on electron temperature are taken into account. Also, the temperature-dependent electron-phonon coupling factor, electron thermal conductivity, and electron heat capacity are used in the simulations. Based on this model, the dependence of the integral reflectivity on pulse fluence, the changes in the film thickness, and the evolution of density and electron and lattice temperatures are obtained. Moreover, snapshots that show the melting and disintegration processes are presented. The disintegration starts at a fluence of 4200 J/m2, which corresponds with an absorbed fluence of 616 J/m2. The calculated values of integral reflectivity are in good agreement with the experimental data. The inclusion of such temperature-dependent absorption models in the TTM-MD method would facilitate the comparison of experimental data with simulation results.

Bimolecular Rate Constants for FAD-Dependent Glucose Dehydrogenase from Aspergillus terreus and Organic Electron Acceptors.

Science.gov (United States)

Tsuruoka, Nozomu; Sadakane, Takuya; Hayashi, Rika; Tsujimura, Seiya

2017-03-10

The flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) from Aspergillus species require suitable redox mediators to transfer electrons from the enzyme to the electrode surface for the application of bioelectrical devices. Although several mediators for FAD-GDH are already in use, they are still far from optimum in view of potential, kinetics, sustainability, and cost-effectiveness. Herein, we investigated the efficiency of various phenothiazines and quinones in the electrochemical oxidation of FAD-GDH from Aspergillus terreus . At pH 7.0, the logarithm of the bimolecular oxidation rate constants appeared to depend on the redox potentials of all the mediators tested. Notably, the rate constant of each molecule for FAD-GDH was approximately 2.5 orders of magnitude higher than that for glucose oxidase from Aspergillus sp. The results suggest that the electron transfer kinetics is mainly determined by the formal potential of the mediator, the driving force of electron transfer, and the electron transfer distance between the redox active site of the mediator and the FAD, affected by the steric or chemical interactions. Higher k ₂ values were found for ortho-quinones than for para-quinones in the reactions with FAD-GDH and glucose oxidase, which was likely due to less steric hindrance in the active site in the case of the ortho-quinones.

Bimolecular Rate Constants for FAD-Dependent Glucose Dehydrogenase from Aspergillus terreus and Organic Electron Acceptors

Directory of Open Access Journals (Sweden)

Nozomu Tsuruoka

2017-03-01

Full Text Available The flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH from Aspergillus species require suitable redox mediators to transfer electrons from the enzyme to the electrode surface for the application of bioelectrical devices. Although several mediators for FAD-GDH are already in use, they are still far from optimum in view of potential, kinetics, sustainability, and cost-effectiveness. Herein, we investigated the efficiency of various phenothiazines and quinones in the electrochemical oxidation of FAD-GDH from Aspergillus terreus. At pH 7.0, the logarithm of the bimolecular oxidation rate constants appeared to depend on the redox potentials of all the mediators tested. Notably, the rate constant of each molecule for FAD-GDH was approximately 2.5 orders of magnitude higher than that for glucose oxidase from Aspergillus sp. The results suggest that the electron transfer kinetics is mainly determined by the formal potential of the mediator, the driving force of electron transfer, and the electron transfer distance between the redox active site of the mediator and the FAD, affected by the steric or chemical interactions. Higher k2 values were found for ortho-quinones than for para-quinones in the reactions with FAD-GDH and glucose oxidase, which was likely due to less steric hindrance in the active site in the case of the ortho-quinones.

Angular Dependence of the Ion-Induced Secondary Electron Emission for He+ and Ga+ Beams

NARCIS (Netherlands)

Castaldo, V.; Withagen, J.; Hagen, C.; Kruit, P.; Van Veldhoven, E.

2011-01-01

In recent years, novel ion sources have been designed and developed that have enabled focused ion beam machines to go beyond their use as nano-fabrication tools. Secondary electrons are usually taken to form images, for their yield is high and strongly dependent on the surface characteristics, in

Quantitatively identical orientation-dependent ionization energy and electron affinity of diindenoperylene

Energy Technology Data Exchange (ETDEWEB)

Han, W. N.; Yonezawa, K.; Makino, R.; Kato, K.; Hinderhofer, A.; Ueno, N.; Kera, S. [Graduate School of Advanced Integration Science, Chiba University 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Murdey, R.; Shiraishi, R.; Yoshida, H.; Sato, N. [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

2013-12-16

Molecular orientation dependences of the ionization energy (IE) and the electron affinity (EA) of diindenoperylene (DIP) films were studied by using ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. The molecular orientation was controlled by preparing the DIP films on graphite and SiO{sub 2} substrates. The threshold IE and EA of DIP thin films were determined to be 5.81 and 3.53 eV for the film of flat-lying DIP orientation, respectively, and 5.38 and 3.13 eV for the film of standing DIP orientation, respectively. The result indicates that the IE and EA for the flat-lying film are larger by 0.4 eV and the frontier orbital states shift away from the vacuum level compared to the standing film. This rigid energy shift is ascribed to a surface-electrostatic potential produced by the intramolecular polar bond (>C{sup −}-H{sup +}) for standing orientation and π-electron tailing to vacuum for flat-lying orientation.

Power Dependence of the Electron Mobility Profile in a Hall Thruster

Science.gov (United States)

Jorns, Benjamin A.; Hofery, Richard H.; Mikellides, Ioannis G.

2014-01-01

The electron mobility profile is estimated in a 4.5 kW commercial Hall thruster as a function of discharge power. Internal measurements of plasma potential and electron temperature are made in the thruster channel with a high-speed translating probe. These measurements are presented for a range of throttling conditions from 150 - 400 V and 0.6 - 4.5 kW. The fluid-based solver, Hall2De, is used in conjunction with these internal plasma parameters to estimate the anomalous collision frequency profile at fixed voltage, 300 V, and three power levels. It is found that the anomalous collision frequency profile does not change significantly upstream of the location of the magnetic field peak but that the extent and magnitude of the anomalous collision frequency downstream of the magnetic peak does change with thruster power. These results are discussed in the context of developing phenomenological models for how the collision frequency profile depends on thruster operating conditions.

A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states.

Science.gov (United States)

Miranda, R P; Fisher, A J; Stella, L; Horsfield, A P

2011-06-28

The solution of the time-dependent Schrödinger equation for systems of interacting electrons is generally a prohibitive task, for which approximate methods are necessary. Popular approaches, such as the time-dependent Hartree-Fock (TDHF) approximation and time-dependent density functional theory (TDDFT), are essentially single-configurational schemes. TDHF is by construction incapable of fully accounting for the excited character of the electronic states involved in many physical processes of interest; TDDFT, although exact in principle, is limited by the currently available exchange-correlation functionals. On the other hand, multiconfigurational methods, such as the multiconfigurational time-dependent Hartree-Fock (MCTDHF) approach, provide an accurate description of the excited states and can be systematically improved. However, the computational cost becomes prohibitive as the number of degrees of freedom increases, and thus, at present, the MCTDHF method is only practical for few-electron systems. In this work, we propose an alternative approach which effectively establishes a compromise between efficiency and accuracy, by retaining the smallest possible number of configurations that catches the essential features of the electronic wavefunction. Based on a time-dependent variational principle, we derive the MCTDHF working equation for a multiconfigurational expansion with fixed coefficients and specialise to the case of general open-shell states, which are relevant for many physical processes of interest.

Dependence of radar auroral scattering cross section on the ambient electron density and the destabilizing electric field

International Nuclear Information System (INIS)

Haldoupis, C.; Nielsen, E.; Schlegel, K.

1990-01-01

By using a data set that includes simultaneous STARE and EISCAT measurements made at a common magnetic flux tube E region in the ionosphere, we investigate the dependence of relative scattering cross section of 1-meter auroral irregularities on the destabilizing E x B electron drift, or alternatively the electric field, and the E region ambient electron density. The analysis showed that both, the E field and mean electron density are the decisive factors in determining the strength of radar auroral echoes at magnetic aspect angles near perpendicularity. We have found that at instability threshold, i.e., when the E field strength is in the 15 to 20 mV/m range, the backscatter power level is affected strongly by the mean electron density. Above threshold, the wave saturation amplitudes are determined mainly by the combined action of electron drift velocity magnitude, V d , and mean electron density, N e , in a way that the scattering cross section, or the electron density fluctuation level, increases with electric field magnitude but at a rate which is larger when the ambient electron density is lower. The analysis enabled us to infer an empirical functional relationship which is capable of predicting reasonably well the intensity of STARE echoes from EISCAT E field and electron density data. In this functional relationship, the received power at threshold depends on N e 2 whereas, from threshold to perhaps more than 50 mV/m, the power increases nonlinearly with drift velocity as V d n where the exponent n is approximately proportional to N e -1/2 . The results support the Farley-Bunemann instability as the primary instability mechanism, but the existing nonlinear treatment of the theory, which includes wave-induced cross field diffusion, cannot account for the observed role of electron density in the saturation of irregularity amplitudes

Electron Beam Irradiation Dose Dependently Damages the Bacillus Spore Coat and Spore Membrane

Directory of Open Access Journals (Sweden)

S. E. Fiester

2012-01-01

Full Text Available Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB irradiation has been frequently chosen to eradicate Bacillus spores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation on Bacillus spores. To study this, B. atrophaeus spores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy. Irradiated spores were found (1 to contain structural damage as observed by electron microscopy, (2 to have spilled cytoplasmic contents as measured by spectroscopy, (3 to have reduced membrane integrity as determined by fluorescence cytometry, and (4 to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation.

Conformational changes of the NADPH-dependent cytochrome P450 reductase in the course of electron transfer to cytochromes P450

DEFF Research Database (Denmark)

Laursen, Tomas; Jensen, Kenneth; Møller, Birger Lindberg

2011-01-01

The NADPH-dependent cytochrome P450 reductase (CPR) is a key electron donor to eucaryotic cytochromes P450 (CYPs). CPR shuttles electrons from NADPH through the FAD and FMN-coenzymes into the iron of the prosthetic heme-group of the CYP. In the course of these electron transfer reactions, CPR und...... to serve as an effective electron transferring "nano-machine"....

Structural Dependence of Electronic Properties in A-A-D-A-A-Type Organic Solar Cell Material

Directory of Open Access Journals (Sweden)

Ram S. Bhatta

2015-01-01

Full Text Available Small conjugated molecules (SCMs are promising candidates for organic photovoltaic (OPV devices because of their structural simplicity, well control over synthetic reproducibility, and low purification cost. However, industrial development of SCM-based OPV devices requires improving their performance, which in turn relies on the fundamental understanding of structural dependence of electronic properties of SCMs. Herein, we report the structural and electronic properties of the BCNDTS molecule as a model system for acceptor-acceptor-donor-acceptor-acceptor (A-A-D-A-A type SCMs, using density functional theory (DFT and time-dependent DFT methods. Systematic calculations of two-dimensional potential energy surfaces, molecular electrostatic potential surfaces, ground state frontier molecular orbital energies, and the vertical excitation energies are performed. We found that the lowest energy conformation of the BCNDTS molecule is planar. The planar conformation favors the lowest ground state and the excited state energies as well as the strongest oscillator strength. The present results suggest that SCMs containing central dithienosilole cores connected with 2,1,3-benzothiadiazole groups have potential to be an efficient electron donor for OPV devices.

Loss of coping resources and psychological distress in spouses of alcohol dependents following partner violence

Directory of Open Access Journals (Sweden)

Ottilingam Somasundaram Ravindran

2017-01-01

Full Text Available Background and Objectives: A study to assess the psychological distress of married women due to their spousal violence under alcohol dependence. This study is aimed at studying partner violence, various coping styles and psychological distress among spouses of men with alcohol dependence and to explore the association between partner violence and coping behaviour. Materials and Methods: The study was conducted on 50 wives of alcohol dependent individuals in the age range of 20-50 years, who were divided into two groups based on the duration of drinking of their husbands. They were assessed by GHQ-12, Measure of Wife Abuse, Coping with Drinking Questionnaire and Depression Anxiety and Stress Scale. Results: Partner alcohol use was associated with increased psychological distress in their spouses and they have used both adaptive and maladaptive coping strategies. Conclusion: Alcohol plays a role in partner violence and spousal mental distress resulting in loss of their coping resources.

Resolution-of-identity stochastic time-dependent configuration interaction for dissipative electron dynamics in strong fields.

Science.gov (United States)

Klinkusch, Stefan; Tremblay, Jean Christophe

2016-05-14

In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.

Resolution-of-identity stochastic time-dependent configuration interaction for dissipative electron dynamics in strong fields

Energy Technology Data Exchange (ETDEWEB)

Klinkusch, Stefan; Tremblay, Jean Christophe [Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin (Germany)

2016-05-14

In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.

Electronic Human Resources Management (e-HRM Adoption Studies: Past and Future Research

Directory of Open Access Journals (Sweden)

Winarto Winarto

2018-05-01

Full Text Available Electronic human resource management (e-HRM systems become more widely used by profit and non-profit organization. However, the field currently lacks sound theoretical frameworks that can be useful in addressing a key issue concerning the implementation of e-HRM systems, in particular to obtain a better understanding of the factors influencing the adoption of e-HRM systems. The objective of this paper is to provide a foundation towards the development of a theoretical framework for the implementation of e-HRM systems and develop a conceptual model that would reflect the nature of e-HRM systems’ adoption through systematic literature review. Adopting Crossan and Apaydin’s procedure of systematic review, this paper investigated 21 empirical papers of electronics human resources management, then categorized them into 4 characteristics which influence the adoption; System and technology characteristics; Organizational characteristics; User/individual characteristics, and Environmental and contextual characteristics. Finally, the e-HRM adoption research framework is drawn and based on the framework; avenues for future research are discussed.   Bahasa Indonesia Abstrak: Manajemen sumber daya manusia elektronik (selanjutnya disebut dengan e-HRM semakin banyak digunakan oleh organisasi profit dan nonprofit. Namun, bidang dan topik ini belum memiliki kerangka teori yang mapan, yang dapat digunakan untuk menganalisis isu-isu terkait penerapan e-HRM, terutama mengenai faktor-faktor yang mempengaruhi adopsi sistem e-HRM. Tujuan penelitian ini adalah untuk memberikan landasan bagi pengembangan kerangka teoritis untuk implementasi sistem e-HRM dan mengembangkan model konseptual yang akan menggambarkan adopsi sistem e-HRM melalui tinjauan literatur sistematis. Mengadopsi prosedur dan metode Crossan dan Apaydin untuk melakukan telaah literatur secara sistematis, paper ini menyelidiki 21 publikasi empiris manajemen sumber daya manusia elektronik dari 2

The effects of density dependent resource limitation on size of wild reindeer.

Science.gov (United States)

Skogland, Terje

1983-11-01

A density-dependent decrement in size for wild reindeer from 12 different Norwegian herds at 16 different densities was shown using lower jawbone-length as the criterion of size. This criterion was tested and found to adequately predict body size of both bucks and does. Lactation in does did not affect jaw length but significantly affected dressed weights.A decrement in the size of does as a result of gross density was found. This size decrement was further analysed in relation to the habitat densities in winter (R 2 =0.85) and in summer (R 2 =0.75) separately, in order to estimate the relative effects of each factor. For herds with adequate food in winter (no signs of overgrazing of lichens) density in relation to summer habitat and mires yielded the highest predictive power in a multiple regression. For herds with adequate summer pastures, densities per winter habitat and lichen volumes showed likewise a highly significant correlation. The inclusion of the lichen volume data in the regression increased its predictive power. The major effect of resource limitation was to delay the time of calving because a maternal carry-over effect allowed the calf a shorter period of growth to be completed during its first summer. Neonate size at birth was highly correlated with maternal size regardless of the mean calving date although the latter was significantly delayed for small-sized does in food resource-limited herds. Likewise the postnatal growth rate of all calves were not significantly different during 50 days postpartum regardless of maternal conditions in winter feeding. The summer growth rates of bucks ≧1 year did not vary significantly between herds. The age of maturity of food resource-limited does was delayed by one year and growth ceased after the initiation of reproduction. This shows that under conditions of limited resources the does with delayed births of calves allocated less energy to body growth simply because they had less time to replenish body

Energetic Constraints on H-2-Dependent Terminal Electron Accepting Processes in Anoxic Environments

DEFF Research Database (Denmark)

Heimann, Axel Colin; Jakobsen, Rasmus; Blodau, C.

2010-01-01

and sulfate reduction are under direct thermodynamic control in soils and sediments and generally approach theoretical minimum energy thresholds. If H-2 concentrations are lowered by thermodynamically more potent TEAPs, these processes are inhibited. This principle is also valid for TEAPS providing more free......Microbially mediated terminal electron accepting processes (TEAPs) to a large extent control the fate of redox reactive elements and associated reactions in anoxic soils, sediments, and aquifers. This review focuses on thermodynamic controls and regulation of H-2-dependent TEAPs, case studies...... illustrating this concept and the quantitative description of thermodynamic controls in modeling. Other electron transfer processes are considered where appropriate. The work reviewed shows that thermodynamics and microbial kinetics are connected near thermodynamic equilibrium. Free energy thresholds...

Parametric dependencies of JET electron temperature profiles

Energy Technology Data Exchange (ETDEWEB)

Schunke, B [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Imre, K; Riedel, K [New York Univ., NY (United States)

1994-07-01

The JET Ohmic, L-Mode and H-Mode electron temperature profiles obtained from the LIDAR Thomson Scattering Diagnostic are parameterized in terms of the normalized flux parameter and a set of the engineering parameters like plasma current, toroidal field, line averages electron density... It is shown that the electron temperature profiles fit a log-additive model well. It is intended to use the same model to predict the profile shape for D-T discharges in JET and in ITER. 2 refs., 5 figs.

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).

Improving Electronic Resources through Holistic Budgeting

Science.gov (United States)

Kusik, James P.; Vargas, Mark A.

2009-01-01

To establish a more direct link between its collections and the educational goals of Saint Xavier University, the Byrne Memorial Library has adopted a "holistic" approach to collection development. This article examines how traditional budget practices influenced the library's selection of resources and describes how holistic collection…

Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

Directory of Open Access Journals (Sweden)

Martha Ingrid Preddie

2008-03-01

Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

Pulse Radiolysis Studies of Temperature Dependent Electron Transfers among Redox Centers in ba(3)-Cytochrome c Oxidase from Thermus thermophilus

DEFF Research Database (Denmark)

Farver, Ole; Wherland, Scot; Antholine, William E

2010-01-01

The functioning of cytochrome c oxidases involves orchestration of long-range electron transfer (ET) events among the four redox active metal centers. We report the temperature dependence of electron transfer from the Cu(A)(r) site to the low-spin heme-(a)b(o) site, i.e., Cu(A)(r) + heme-a(b)(o) ......The functioning of cytochrome c oxidases involves orchestration of long-range electron transfer (ET) events among the four redox active metal centers. We report the temperature dependence of electron transfer from the Cu(A)(r) site to the low-spin heme-(a)b(o) site, i.e., Cu(A)(r) + heme...... in cytochrome ba(3) had no effect on the rate of this reaction whereas the II-Met160Leu Cu(A)-mutation was slower by an amount corresponding to a decreased driving force of ∼0.06 eV. The structures support the presence of a common, electron-conducting "wire" between Cu(A) and heme-a(b). The transfer...

Temperature dependence of electron mobility, electroluminescence and photoluminescence of Alq{sub 3} in OLED

Energy Technology Data Exchange (ETDEWEB)

Mu Haichuan; White, Dan; Sharpton, Buck [Office of Electronic Miniaturization, University of Alaska at Fairbanks, AK 99701 (United States); Klotzkin, David [Department of Electrical and Computer Engineering and Computer Sciences, University of Cincinnati, Cincinnati, OH 45221 (United States); De Silva, Ajith; Wagner, Hans Peter [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States)], E-mail: fnhm@uaf.edu

2008-12-07

The correlation of electroluminescence (EL), photoluminescence (PL) and electron mobility were investigated over temperature from 60 to 300 K in small-molecule organic light emitting diode (OLED) structures. The devices consisted of ITO/PEDOT(50 nm)/TPD(50 nm)/Alq{sub 3}(60 nm)/LiF(1 nm)/Al(90 nm), and were fabricated with high-vacuum sublimation/evaporation in a cross-linked configuration. Electron mobility was measured using an ac analysis of the device optical modulation characteristics, while PL and EL were measured by measuring optical power out at fixed pump power of 1 mW, and analysis of dc brightness-voltage (L-V) characteristics, respectively. PL intensity and mobility had a clear maximum at around 220 K, while EL efficiency was constant below 220 K and decrease monotonically above. The reason for the temperature dependent EL, PL and electron mobility behaviour will be discussed.

Penetration length-dependent hot electrons in the field emission from ZnO nanowires

Science.gov (United States)

Chen, Yicong; Song, Xiaomeng; Li, Zhibing; She, Juncong; Deng, Shaozhi; Xu, Ningsheng; Chen, Jun

2018-01-01

In the framework of field emission, whether or not hot electrons can form in the semiconductor emitters under a surface penetration field is of great concern, which will provide not only a comprehensive physical picture of field emission from semiconductor but also guidance on how to improve device performance. However, apart from some theoretical work, its experimental evidence has not been reported yet. In this article, the field penetration length-dependent hot electrons were observed in the field emission of ZnO nanowires through the in-situ study of its electrical and field emission characteristic before and after NH3 plasma treatment in an ultrahigh vacuum system. After the treatment, most of the nanowires have an increased carrier density but reduced field emission current. The raised carrier density was caused by the increased content of oxygen vacancies, while the degraded field emission current was attributed to the lower kinetic energy of hot electrons caused by the shorter penetration length. All of these results suggest that the field emission properties of ZnO nanowires can be optimized by modifying their carrier density to balance both the kinetic energy of field induced hot electrons and the limitation of saturated current under a given field.

Fossile fuel and uranium resources

International Nuclear Information System (INIS)

Gorkum, A.A. van.

1975-01-01

The world's resources of coal, lignite, oil, natural gas, shale oil and uranium are reviewed. These quantities depend on the prices which make new resources exploitable. Uranium resources are given exclusively for the USSR, Eastern Europe and China. Their value in terms of energy depends heavily on the reactor type used. All figures given are estimated to be conservative

Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

Science.gov (United States)

Friege, Henning

2012-09-01

For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

Science.gov (United States)

Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

2013-01-01

In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

The dependence of electronic transport on compressive deformation of C{sub 60} molecule

Energy Technology Data Exchange (ETDEWEB)

Li, H. [Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University (China)], E-mail: lihuilmy@hotmail.com; Zhang, X.Q. [Physics Department, Ocean University of China, Qingdao (China)

2008-06-02

The dependence of electronic transport on compressive deformation of C{sub 60} molecule is studied theoretically in this work. Brenner's 'second generation' empirical potential is used to describe the many-body short-range interatomic interactions for C{sub 60} in the molecular dynamics simulations. Our results demonstrate that C{sub 60} can be compressed up to a strain {epsilon}=0.31 before collapsing. Electronic transport under an applied bias is calculated by using a self-consistent field approach coupled with non-equilibrium Green's function (NEGF) formalism. The transmission probability, conductance gap, and conductance spectrum are found to be sensitive to the compression. The peak value of conductance decreases with the increase of strain until the C{sub 60} is compressed up to a strain {epsilon}=0.31.

Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms.

Science.gov (United States)

Perkins, R; Williamson, C; Lavaud, J; Mouget, J-L; Campbell, D A

2018-04-16

Photoacclimation by strains of Haslea "blue" diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction-recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m -2  s -1 photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σ PSII ') or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σ PSII ' in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. Q A - oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction-recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment.

Stacking-dependent electronic property of trilayer graphene epitaxially grown on Ru(0001)

Energy Technology Data Exchange (ETDEWEB)

Que, Yande; Xiao, Wende, E-mail: wdxiao@iphy.ac.cn, E-mail: hjgao@iphy.ac.cn; Chen, Hui; Wang, Dongfei; Du, Shixuan; Gao, Hong-Jun, E-mail: wdxiao@iphy.ac.cn, E-mail: hjgao@iphy.ac.cn [Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China)

2015-12-28

The growth, atomic structure, and electronic property of trilayer graphene (TLG) on Ru(0001) were studied by low temperature scanning tunneling microscopy and spectroscopy in combined with tight-binding approximation (TBA) calculations. TLG on Ru(0001) shows a flat surface with a hexagonal lattice due to the screening effect of the bottom two layers and the AB-stacking in the top two layers. The coexistence of AA- and AB-stacking in the bottom two layers leads to three different stacking orders of TLG, namely, ABA-, ABC-, and ABB-stacking. STS measurements combined with TBA calculations reveal that the density of states of TLG with ABC- and ABB-stacking is characterized by one and two sharp peaks near to the Fermi level, respectively, in contrast to the V-shaped feature of TLG with ABA-stacking. Our work demonstrates that TLG on Ru(0001) might be an ideal platform for exploring stacking-dependent electronic properties of graphene.

Electron tunneling in lithium-ammonia solutions probed by frequency-dependent electron spin relaxation studies.

Science.gov (United States)

Maeda, Kiminori; Lodge, Matthew T J; Harmer, Jeffrey; Freed, Jack H; Edwards, Peter P

2012-06-06

Electron transfer or quantum tunneling dynamics for excess or solvated electrons in dilute lithium-ammonia solutions have been studied by pulse electron paramagnetic resonance (EPR) spectroscopy at both X- (9.7 GHz) and W-band (94 GHz) frequencies. The electron spin-lattice (T(1)) and spin-spin (T(2)) relaxation data indicate an extremely fast transfer or quantum tunneling rate of the solvated electron in these solutions which serves to modulate the hyperfine (Fermi-contact) interaction with nitrogen nuclei in the solvation shells of ammonia molecules surrounding the localized, solvated electron. The donor and acceptor states of the solvated electron in these solutions are the initial and final electron solvation sites found before, and after, the transfer or tunneling process. To interpret and model our electron spin relaxation data from the two observation EPR frequencies requires a consideration of a multiexponential correlation function. The electron transfer or tunneling process that we monitor through the correlation time of the nitrogen Fermi-contact interaction has a time scale of (1-10) × 10(-12) s over a temperature range 230-290 K in our most dilute solution of lithium in ammonia. Two types of electron-solvent interaction mechanisms are proposed to account for our experimental findings. The dominant electron spin relaxation mechanism results from an electron tunneling process characterized by a variable donor-acceptor distance or range (consistent with such a rapidly fluctuating liquid structure) in which the solvent shell that ultimately accepts the transferring electron is formed from random, thermal fluctuations of the liquid structure in, and around, a natural hole or Bjerrum-like defect vacancy in the liquid. Following transfer and capture of the tunneling electron, further solvent-cage relaxation with a time scale of ∼10(-13) s results in a minor contribution to the electron spin relaxation times. This investigation illustrates the great

Electron Tunneling in Lithium Ammonia Solutions Probed by Frequency-Dependent Electron-Spin Relaxation Studies

Science.gov (United States)

Maeda, Kiminori; Lodge, Matthew T.J.; Harmer, Jeffrey; Freed, Jack H.; Edwards, Peter P.

2012-01-01

Electron transfer or quantum tunneling dynamics for excess or solvated electrons in dilute lithium-ammonia solutions have been studied by pulse electron paramagnetic resonance (EPR) spectroscopy at both X- (9.7 GHz) and W-band (94 GHz) frequencies. The electron spin-lattice (T1) and spin-spin (T2) relaxation data indicate an extremely fast transfer or quantum tunneling rate of the solvated electron in these solutions which serves to modulate the hyperfine (Fermi-contact) interaction with nitrogen nuclei in the solvation shells of ammonia molecules surrounding the localized, solvated electron. The donor and acceptor states of the solvated electron in these solutions are the initial and final electron solvation sites found before, and after, the transfer or tunneling process. To interpret and model our electron spin relaxation data from the two observation EPR frequencies requires a consideration of a multi-exponential correlation function. The electron transfer or tunneling process that we monitor through the correlation time of the nitrogen Fermi-contact interaction has a time scale of (1–10)×10−12 s over a temperature range 230–290K in our most dilute solution of lithium in ammonia. Two types of electron-solvent interaction mechanisms are proposed to account for our experimental findings. The dominant electron spin relaxation mechanism results from an electron tunneling process characterized by a variable donor-acceptor distance or range (consistent with such a rapidly fluctuating liquid structure) in which the solvent shell that ultimately accepts the transferring electron is formed from random, thermal fluctuations of the liquid structure in, and around, a natural hole or Bjerrum-like defect vacancy in the liquid. Following transfer and capture of the tunneling electron, further solvent-cage relaxation with a timescale of ca. 10−13 s results in a minor contribution to the electron spin relaxation times. This investigation illustrates the great potential

Designing a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology

Directory of Open Access Journals (Sweden)

Mirali Seyednaghavi

2017-06-01

Full Text Available : In the first phase of this study a model for electronic human resource management in government agencies based on new public services was explored by using software MAXQDA, then in the second phase, relationship between the elements of the theory were tested using software Smart PLS2. So the aim of this study is to design a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology. In this regard, according to Strauss and Corbin’s structured plan, five hypotheses were tested. Quantitative data analysis indicates that the pressures of the policies and global perspectives cause to move toward e-HRM. Among the contextual conditions macro structural mechanisms, considerations of actors, governance considerations have a significant impact on the strategy of new public services and therefore lead to the consequences of its implementation in public organizations. The findings suggest that e-HRM does not have a positive and meaningful impact on new public services, and in our country, although the recent political developments have somehow removed the gap between public policy makers, administrators, and the public, but there is still a long way to go.

Electronic access to scientific nursing knowledge: the Virginia Henderson International Nursing Library.

Science.gov (United States)

Graves, J R

2001-02-01

To inform oncology nurses about the electronic knowledge resources offered by the Sigma Theta Tau International Virginia Henderson International Nursing Library. Published articles and research studies. Clinical nursing research dissemination has been seriously affected by publication bias. The Virginia Henderson International Nursing Library has introduced both a new publishing paradigm for research and a new knowledge indexing strategy for improving electronic access to research knowledge (findings). The ability of oncology nursing to evolve, as an evidence-based practice, is largely dependent on access to research findings.

Resourcefulness training intervention: a promising approach to improve mental health of mothers with technology-dependent children.

Science.gov (United States)

Toly, Valerie Boebel; Musil, Carol M; Zauszniewski, Jaclene A

2014-02-01

The population of children dependent on medical technology such as mechanical ventilation, feeding tubes, and supplemental oxygen continues to grow in the United States. These children are frequently cared for by their mothers at home following hospital discharge. Research indicates that these mothers are at high risk for negative mental health outcomes that affect both caregiver and care recipient. The purpose of this randomized controlled pilot trial was to determine the feasibility, acceptability, and efficacy of resourcefulness training (RT), a cognitive-behavioral intervention, among mothers of technology-dependent children. RT was found to be a feasible and acceptable intervention with this population during the 6 week study. The effect size in this pilot study demonstrates initial efficacy and indicates areas for strengthening the intervention protocol. RT is a promising intervention that can be employed by pediatric nurses to assist mothers in the home management of technology-dependent children. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of combined platinum and electron on the temperature dependence of forward voltage in fast recovery diode

International Nuclear Information System (INIS)

Jia Yun-Peng; Zhao Bao; Wu Yu; Zhou Xuan; Li Zhe; Tan Jian; Yang Fei

2015-01-01

The temperature dependences of forward voltage drop (V F ) of the fast recovery diodes (FRDs) are remarkably influenced by different lifetime controlled treatments. In this paper the results of an experimental study are presented, which are the lifetime controls of platinum treatment, electron irradiation treatment, and the combined treatment of the above ones. Based on deep level transient spectroscopy (DLTS) measurements, a new level E6 (E C -0.376 eV) is found in the combined lifetime treated (CLT) sample, which is different from the levels of the individual platinum and electron irradiation ones. Comparing the tested V F results of CLT samples with the others, the level E6 is responsible for the degradation of temperature dependence of the forward voltage drop in the FRD. (paper)

The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

Directory of Open Access Journals (Sweden)

Ольга Николаевна Крылова

2009-06-01

Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

Spin—Dependent Scattering Effects and Dimensional Crossover in a Quasi—Two—Dimensional Disordered Electron System

Institute of Scientific and Technical Information of China (English)

YANGYong－Hong; WANGYong－Gang; 等

2002-01-01

Two kinds of spin-dependent scattering effects (magnetic-impurity and spin-orbit scatterings) are investigated theoretically in a quasi-tow-dimensional (quasi-2D) disordered electron system.By making use of the diagrammatic techniques in perturbation theory,we have calculated the dc conductivity and magnetoresistance due to weak-localization effects,the analytical expressions of them are obtained as functions of the interlayer hopping energy and the characteristic times:elastic,inelastic,magnetic and spin-orbit scattering times.The relevant dimensional crossover behavior from 3D to 2D with decreasing the interlayer coupling is discussed,and the condition for the crossover is shown to be dependent on the aforementioned scattering times.At low temperature there exists a spin-dependent-scattering-induced dimensional crossover in this system.

Time-dependent theory of Raman scattering for systems with several excited electronic states: Application to a H+3 model system

International Nuclear Information System (INIS)

Heather, R.; Metiu, H.

1989-01-01

The time-dependent formulation of Raman scattering theory is used to study how nonadiabatic interactions affect the Raman spectrum of a model H + 3 system, which has two excited electronic states. We start with a formula derived by Heller which gives the Raman scattering cross section as the Fourier transform (over time) of a time-dependent overlap integral. The latter is calculated with a method proposed by Fleck, Morris, and Feit, and extended to curve crossing by Alvarellos and Metiu. In performing these calculations we are especially interested in displaying effects typical of systems having more than one upper state. If the incident laser populates two electronic states there are several ways (i.e., excite to state one and emit from state two, excite to state one, and emit from state one, etc.) by which the Raman process can reach a given final state, and this leads to quantum interference. This interference is manifested in the Raman cross section as approximate selection rules controlling which final states can be reached through the Raman process. These selection rules depend on the relative orientation of the transition dipoles that radiatively couple the ground electronic state with the excited electronic states. The magnitude of the nonadiabatic contribution to the Raman emission, e.g., the contribution from absorbing to state one and emitting from state two, can be determined from the polarization dependence of the Raman emission if the transition dipoles have neither parallel nor antiparallel relative orientation

Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

Science.gov (United States)

Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

2015-01-01

The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

Persistence in ratio-dependent models of consumer-resource dynamics

Directory of Open Access Journals (Sweden)

Claude Lobry

2007-02-01

Full Text Available In a recent work Cantrell, Cosner and Ruan show that intraspecific interference is responsible for coexistence of many consumers for one resource with a logistic like growth rate. Recently, we have established a similar result for the case of a chemostat using a rather different technique. In the present note, we complement these two works to the case of an unknown nonlinear growth rate for the resource satisfying mild assumptions.

Time-dependent reduced density matrix functional theory applied to laser-driven, correlated two-electron dynamics

Energy Technology Data Exchange (ETDEWEB)

Brics, Martins; Kapoor, Varun; Bauer, Dieter [Institut fuer Physik, Universitaet Rostock, 18051 Rostock (Germany)

2013-07-01

Time-dependent density functional theory (TDDFT) with known and practicable exchange-correlation potentials does not capture highly correlated electron dynamics such as single-photon double ionization, autoionization, or nonsequential ionization. Time-dependent reduced density matrix functional theory (TDRDMFT) may remedy these problems. The key ingredients in TDRDMFT are the natural orbitals (NOs), i.e., the eigenfunctions of the one-body reduced density matrix (1-RDM), and the occupation numbers (OCs), i.e., the respective eigenvalues. The two-body reduced density matrix (2-RDM) is then expanded in NOs, and equations of motion for the NOs can be derived. If the expansion coefficients of the 2-RDM were known exactly, the problem at hand would be solved. In practice, approximations have to be made. We study the prospects of TDRDMFT following a top-down approach. We solve the exact two-electron time-dependent Schroedinger equation for a model Helium atom in intense laser fields in order to study highly correlated phenomena such as the population of autoionizing states or single-photon double ionization. From the exact wave function we calculate the exact NOs, OCs, the exact expansion coefficients of the 2-RDM, and the exact potentials in the equations of motion. In that way we can identify how many NOs and which level of approximations are necessary to capture such phenomena.

L-tryptophan-induced electron transport across supported lipid bilayers: an alkyl-chain tilt-angle, and bilayer-symmetry dependence.

Science.gov (United States)

Sarangi, Nirod Kumar; Patnaik, Archita

2012-12-21

Molecular orientation-dependent electron transport across supported 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers (SLBs) on semiconducting indium tin oxide (ITO) is reported with an aim towards potential nanobiotechnological applications. A bifunctional strategy is adopted to form symmetric and asymmetric bilayers of DPPC that interact with L-tryptophan, and are analyzed by surface manometry and atomic force microscopy. Polarization-dependent real-time Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) analysis of these SLBs reveals electrostatic, hydrogen-bonding, and cation-π interactions between the polar head groups of the lipid and the indole side chains. Consequently, a molecular tilt arises from the effective interface dipole, facilitating electron transport across the ITO-anchored SLBs in the presence of an internal Fe(CN)(6)(4-/3-) redox probe. The incorporation of tryptophan enhances the voltammetric features of the SLBs. The estimated electron-transfer rate constants for symmetric and asymmetric bilayers (k(s) = 2.0×10(-2) and 2.8×10(-2) s(-1)) across the two-dimensional (2D) ordered DPPC/tryptophan SLBs are higher compared to pure DPPC SLBs (k(s) = 3.2×10(-3) and 3.9×10(-3) s(-1)). In addition, they are molecular tilt-dependent, as it is the case with the standard apparent rate constants k(app)(0), estimated from electrochemical impedance spectroscopy and bipotentiostatic experiments with a Pt ultramicroelectrode. Lower magnitudes of k(s) and k(app)(0) imply that electrochemical reactions across the ITO-SLB electrodes are kinetically limited and consequently governed by electron tunneling across the SLBs. Standard theoretical rate constants (k(th)(0)) accrued upon electron tunneling comply with the potential-independent electron-tunneling coefficient β = 0.15 Å(-1). Insulator-semiconductor transitions moving from a liquid-expanded to a condensed 2D-phase state of the SLBs are noted, adding a new dimension

Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

Science.gov (United States)

Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

2016-01-01

The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

Shaping the Electronic Library--The UW-Madison Approach.

Science.gov (United States)

Dean, Charles W., Ed.; Frazier, Ken; Pope, Nolan F.; Gorman, Peter C.; Dentinger, Sue; Boston, Jeanne; Phillips, Hugh; Daggett, Steven C.; Lundquist, Mitch; McClung, Mark; Riley, Curran; Allan, Craig; Waugh, David

1998-01-01

This special theme section describes the University of Wisconsin-Madison's experience building its Electronic Library. Highlights include integrating resources and services; the administrative framework; the public electronic library, including electronic publishing capability and access to World Wide Web-based and other electronic resources;…

Secondary emission coefficient dependence on the angle of incidence of primary electrons on CsI and LiF layers. [0. 9 to 3 keV, mechanism

Energy Technology Data Exchange (ETDEWEB)

Shabel' nikova, A E; Yasnopol' skii, N L

1976-08-01

The angular dependence was studied of the secondary emission coefficient sigma for CsI and LiF dielectrics which have large sigma in conditions of normal incidence of primary electrons. Measurements were taken down to the angle of 85 deg for energies of primary electrons between 0.9 and 3 keV. In the whole range of angles a nonmonotonic angular dependence sigma is observed. The dependence shows itself particularly clearly for CsI at large energies of primary electrons. Such a behaviour is due to the decrease in the depth of yield of inelastically reflected electrons and to the increase in the inelastic reflection coefficient of the substance.

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2017-08-22

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

The use of quality benchmarking in assessing web resources for the dermatology virtual branch library of the National electronic Library for Health (NeLH).

Science.gov (United States)

Kamel Boulos, M N; Roudsari, A V; Gordon, C; Muir Gray, J A

2001-01-01

In 1998, the U.K. National Health Service Information for Health Strategy proposed the implementation of a National electronic Library for Health to provide clinicians, healthcare managers and planners, patients and the public with easy, round the clock access to high quality, up-to-date electronic information on health and healthcare. The Virtual Branch Libraries are among the most important components of the National electronic Library for Health. They aim at creating online knowledge based communities, each concerned with some specific clinical and other health-related topics. This study is about the envisaged Dermatology Virtual Branch Libraries of the National electronic Library for Health. It aims at selecting suitable dermatology Web resources for inclusion in the forthcoming Virtual Branch Libraries after establishing preliminary quality benchmarking rules for this task. Psoriasis, being a common dermatological condition, has been chosen as a starting point. Because quality is a principal concern of the National electronic Library for Health, the study includes a review of the major quality benchmarking systems available today for assessing health-related Web sites. The methodology of developing a quality benchmarking system has been also reviewed. Aided by metasearch Web tools, candidate resources were hand-selected in light of the reviewed benchmarking systems and specific criteria set by the authors. Over 90 professional and patient-oriented Web resources on psoriasis and dermatology in general are suggested for inclusion in the forthcoming Dermatology Virtual Branch Libraries. The idea of an all-in knowledge-hallmarking instrument for the National electronic Library for Health is also proposed based on the reviewed quality benchmarking systems. Skilled, methodical, organized human reviewing, selection and filtering based on well-defined quality appraisal criteria seems likely to be the key ingredient in the envisaged National electronic Library for

There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

Directory of Open Access Journals (Sweden)

Annie M. Hughes

2013-03-01

Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

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.

Electronic resources access and usage among the postgraduates of ...

African Journals Online (AJOL)

... and usage among the postgraduates of a Nigerian University of Technology. ... faced by postgraduates in using e-resources include takes too much time to find, ... Resources, Access, Use, Postgraduat, Students, University, Technology, Nigeria ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

Layer-dependent anisotropic electronic structure of freestanding quasi-two-dimensional Mo S 2

KAUST Repository

Hong, Jinhua

2016-02-29

The anisotropy of the electronic transition is a well-known characteristic of low-dimensional transition-metal dichalcogenides, but their layer-thickness dependence has not been properly investigated experimentally until now. Yet, it not only determines the optical properties of these low-dimensional materials, but also holds the key in revealing the underlying character of the electronic states involved. Here we used both angle-resolved electron energy-loss spectroscopy and spectral analysis of angle-integrated spectra to study the evolution of the anisotropic electronic transition involving the low-energy valence electrons in the freestanding MoS2 layers with different thicknesses. We are able to demonstrate that the well-known direct gap at 1.8 eV is only excited by the in-plane polarized field while the out-of-plane polarized optical gap is 2.4 ± 0.2 eV in monolayer MoS2. This contrasts with the much smaller anisotropic response found for the indirect gap in the few-layer MoS2 systems. In addition, we determined that the joint density of states associated with the indirect gap transition in the multilayer systems and the corresponding indirect transition in the monolayer case has a characteristic three-dimensional-like character. We attribute this to the soft-edge behavior of the confining potential and it is an important factor when considering the dynamical screening of the electric field at the relevant excitation energies. Our result provides a logical explanation for the large sensitivity of the indirect transition to thickness variation compared with that for the direct transition, in terms of quantum confinement effect.

Layer-dependent anisotropic electronic structure of freestanding quasi-two-dimensional Mo S 2

KAUST Repository

Hong, Jinhua; Li, Kun; Jin, Chuanhong; Zhang, Xixiang; Zhang, Ze; Yuan, Jun

2016-01-01

The anisotropy of the electronic transition is a well-known characteristic of low-dimensional transition-metal dichalcogenides, but their layer-thickness dependence has not been properly investigated experimentally until now. Yet, it not only determines the optical properties of these low-dimensional materials, but also holds the key in revealing the underlying character of the electronic states involved. Here we used both angle-resolved electron energy-loss spectroscopy and spectral analysis of angle-integrated spectra to study the evolution of the anisotropic electronic transition involving the low-energy valence electrons in the freestanding MoS2 layers with different thicknesses. We are able to demonstrate that the well-known direct gap at 1.8 eV is only excited by the in-plane polarized field while the out-of-plane polarized optical gap is 2.4 ± 0.2 eV in monolayer MoS2. This contrasts with the much smaller anisotropic response found for the indirect gap in the few-layer MoS2 systems. In addition, we determined that the joint density of states associated with the indirect gap transition in the multilayer systems and the corresponding indirect transition in the monolayer case has a characteristic three-dimensional-like character. We attribute this to the soft-edge behavior of the confining potential and it is an important factor when considering the dynamical screening of the electric field at the relevant excitation energies. Our result provides a logical explanation for the large sensitivity of the indirect transition to thickness variation compared with that for the direct transition, in terms of quantum confinement effect.

Coupled electron and atomic kinetics through the solution of the Boltzmann equation for generating time-dependent X-ray spectra

International Nuclear Information System (INIS)

Sherrill, M.E.; Abdallah, J. Jr.; Csanak, G.; Kilcrease, D.P.; Dodd, E.S.; Fukuda, Y.; Akahane, Y.; Aoyama, M.; Inoue, N.; Ueda, H.; Yamakawa, K.; Faenov, A.Ya.; Magunov, A.I.; Pikuz, T.A.; Skobelev, I.Yu.

2006-01-01

In this work, we present a model that solves self-consistently the electron and atomic kinetics to characterize highly non-equilibrium plasmas, in particular for those systems where both the electron distribution function is far from Maxwellian and the evolution of the ion level populations are dominated by time-dependent atomic kinetics. In this model, level populations are obtained from a detailed collisional-radiative model where collision rates are computed from a time varying electron distribution function obtained from the solution of the zero-dimensional Boltzmann equation. The Boltzmann collision term includes the effects of electron-electron collisions, electron collisional ionization, excitation and de-excitation. An application for He α spectra from a short pulse laser irradiated argon cluster target will be shown to illustrate the results of our model

Coupled electron and atomic kinetics through the solution of the Boltzmann equation for generating time-dependent X-ray spectra

Energy Technology Data Exchange (ETDEWEB)

Sherrill, M.E. [Los Alamos National Laboratory, T-4, Los Alamos, NM 87545 (United States)]. E-mail: manolo@t4.lanl.gov; Abdallah, J. Jr. [Los Alamos National Laboratory, T-4, Los Alamos, NM 87545 (United States); Csanak, G. [Los Alamos National Laboratory, T-4, Los Alamos, NM 87545 (United States); Kilcrease, D.P. [Los Alamos National Laboratory, T-4, Los Alamos, NM 87545 (United States); Dodd, E.S. [Los Alamos National Laboratory, X-1, Los Alamos, NM 87545 (United States); Fukuda, Y. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Akahane, Y. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Aoyama, M. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Inoue, N. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Ueda, H. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Yamakawa, K. [Advanced Photon Research Center, JAERI, Kyoto 619-0215 (Japan); Faenov, A.Ya. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo, Moscow Region 141570 (Russian Federation); Magunov, A.I. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo, Moscow Region 141570 (Russian Federation); Pikuz, T.A. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo, Moscow Region 141570 (Russian Federation); Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo, Moscow Region 141570 (Russian Federation)

2006-05-15

In this work, we present a model that solves self-consistently the electron and atomic kinetics to characterize highly non-equilibrium plasmas, in particular for those systems where both the electron distribution function is far from Maxwellian and the evolution of the ion level populations are dominated by time-dependent atomic kinetics. In this model, level populations are obtained from a detailed collisional-radiative model where collision rates are computed from a time varying electron distribution function obtained from the solution of the zero-dimensional Boltzmann equation. The Boltzmann collision term includes the effects of electron-electron collisions, electron collisional ionization, excitation and de-excitation. An application for He{sub {alpha}} spectra from a short pulse laser irradiated argon cluster target will be shown to illustrate the results of our model.

Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

Energy Technology Data Exchange (ETDEWEB)

Barilo, Nick F.

2014-09-29

The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

Energy- and temperature dependences of secondary electron emission of CsI- and CsBr layers doped with Cd

International Nuclear Information System (INIS)

Galij, P.V.; Tsal', N.A.

1983-01-01

The energy and temperature dependences of the secondary electron emission coefficient (SEEC) of CsI-Cd-, CsBr-Cd-, CsI-CsBr layers have been studied. The effect of bivalent cadmium impurity on the SEEC value is investigated. It is shown that implantation of small amounts of Cd 2+ impurity into the lattice of the initial monocrystals might increase the SEEC values of the layers. Temperature dependences (TD) of SEEC are measured and the possibility of comparing experimental results with the Dekker formula is analyzed. A conclusion is drawn that the Dekker model well describes the TD of SEEC of doped layers at temperatures T < or approximately 100 deg C. At elevated temperatures., along with secondary electron scattering on phonons, one should take into account their scattering on vacancies

EFFECTIVE ELECTRONIC TUTORIAL

Directory of Open Access Journals (Sweden)

Andrei A. Fedoseev

2014-01-01

Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

Integrated Resource Management and Recovery

DEFF Research Database (Denmark)

Astrup, Thomas Fruergaard

2014-01-01

, depends on the quality of these resources and technological abilities to extract resources from mixed materials, e.g. mobile phones, solar cells, or mixed domestic waste. The "effort" invested in recovery of secondary resources should not be more than the "benefit" associated with the secondary resources...

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....

Survival and growth of epiphytic ferns depend on resource sharing

Directory of Open Access Journals (Sweden)

Hua-Zheng eLu

2016-03-01

Full Text Available Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets and another on groups (several ramets within a plot, with severed and intact rhizome treatments (without and with physiological integration on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

Layer-dependent electronic properties of phosphorene-like materials and phosphorene-based van der Waals heterostructures.

Science.gov (United States)

Huang, Y C; Chen, X; Wang, C; Peng, L; Qian, Q; Wang, S F

2017-06-29

Black phosphorus is a layered semiconducting allotrope of phosphorus with high carrier mobility. Its monolayer form, phosphorene, is an extremely fashionable two-dimensional material which has promising potential in transistors, optoelectronics and electronics. However, phosphorene-like analogues, especially phosphorene-based heterostructures and their layer-controlled electronic properties, are rarely systematically investigated. In this paper, the layer-dependent structural and electronic properties of phosphorene-like materials, i.e., mono- and few-layer MXs (M = Sn, Ge; X = S, Se), are first studied via first-principles calculations, and then the band edge position of these MXs as well as mono- and few-layer phosphorene are aligned. It is revealed that van der Waals heterostructures with a Moiré superstructure formed by mutual coupling among MXs and among MXs and few-layer phosphorene are able to show type-I or type-II characteristics and a I-II or II-I transition can be induced by adjusting the number of layers. Our work is expected to yield a new family of phosphorene-based semiconductor heterostructures with tunable electronic properties through altering the number of layers of the composite.

Role for Distributed Energy Resources (DER) in the Digital Economy

Energy Technology Data Exchange (ETDEWEB)

Key, Thomas S [Electric Power Research Institute (EPRI)

2007-11-01

A large, and growing, part of the Nation's economy either serves or depends upon the information technology industry. These high-tech or "digital" enterprises are characterized by a dependence on electronic devices, need for completely reliable power supply, and intolerance to any power quality problems. In some cases these enterprises are densely populated with electronic loads and have very high energy usage per square foot. Serving these enterprises presents both electric power and equipment cooling challenges. Traditional electric utilities are often hard-pressed to deliver power that meets the stringent requirements of digital customers, and the economic and social consequences of a service quality or reliability problem can be large. New energy delivery and control options must be developed to effectively serve a digital economy. This report explores how distributed energy resources, partnerships between utility and customer to share the responsibility for service quality, innovative facility designs, higher energy efficiencies and waste-heat utilization can be coupled to meet the needs of a growing digital economy.

Orientation-dependent imaging of electronically excited quantum dots

Science.gov (United States)

Nguyen, Duc; Goings, Joshua J.; Nguyen, Huy A.; Lyding, Joseph; Li, Xiaosong; Gruebele, Martin

2018-02-01

We previously demonstrated that we can image electronic excitations of quantum dots by single-molecule absorption scanning tunneling microscopy (SMA-STM). With this technique, a modulated laser beam periodically saturates an electronic transition of a single nanoparticle, and the resulting tunneling current modulation ΔI(x0, y0) maps out the SMA-STM image. In this paper, we first derive the basic theory to calculate ΔI(x0, y0) in the one-electron approximation. For near-resonant tunneling through an empty orbital "i" of the nanostructure, the SMA-STM signal is approximately proportional to the electron density |φi) (x0,y0)|nudge quantum dots on the surface and roll them, thus imaging excited state electronic structure of a single quantum dot at different orientations. We use density functional theory to model ODMs at various orientations, for qualitative comparison with the SMA-STM experiment. The model demonstrates that our experimentally observed signal monitors excited states, localized by defects near the surface of an individual quantum dot. The sub-nanometer super-resolution imaging technique demonstrated here could become useful for mapping out the three-dimensional structure of excited states localized by defects within nanomaterials.

SU-F-I-70: Investigation of Gafchromic EBT3 Film Energy Dependence Using Proton, Photon, and Electron Beams

International Nuclear Information System (INIS)

Ferreira, C; Schnell, E; Ahmad, S; De La Fuente Herman, T

2016-01-01

Purpose: To investigate the energy dependence of Gafchromic EBT3 film over a range of clinically used proton, photon and electron energies. Methods: Proton beam energies of 117 and 204 MeV, corresponding respectively to ranges in water of 10 cm and 27 cm from a Mevion S250 double scatter system unit were used. Electron energies of 6 and 20 MeV and photon energies of 6 and 18 MV from a Varian Clinac 21EX Linac were used. Two pieces of film (5×5 cm"2) were irradiated sequentially for doses of 100, 500, and 1000 cGy for all energies and modalities. Films were placed on the central beam axis for a 10×10 cm"2 field size in the middle of spread out Bragg peak (SOBP) for proton and in respective dmax for photon and electron energies. Films were scanned on a flatbed Epson Expression 10000 XL scanner on the central region of the scanning window using 48-bit, 300 dpi, and landscape orientation after 48 hours post-irradiation of film to account for optical density (OD) stabilization. Film analysis of the red channel was performed using ImageJ 1.48v (National Institutes of Health). Results: The energy dependency of EBT3 among all energies and modalities for all doses studied was small within measurement uncertainties (1σ = ± 4.1%). The mean net OD in red channel for films receiving the same dose in the same energy modality had standard deviations within 0.9% for photons, 4.9% for electrons and 1.8% for protons. It was observed that film pieces were activated during proton irradiation, e.g., 7 mR/hr at surface after 30 minutes of irradiation, lasting for 2 hours post irradiation. Conclusion: EBT3 energy dependency was evaluated for clinically used proton, photon, and electron energies. The film self-activation may have contributed to fog and negligible dose.

SU-F-I-70: Investigation of Gafchromic EBT3 Film Energy Dependence Using Proton, Photon, and Electron Beams

Energy Technology Data Exchange (ETDEWEB)

Ferreira, C; Schnell, E; Ahmad, S; De La Fuente Herman, T [University of Oklahoma Health Science Center, Oklahoma City, OK (United States)

2016-06-15

Purpose: To investigate the energy dependence of Gafchromic EBT3 film over a range of clinically used proton, photon and electron energies. Methods: Proton beam energies of 117 and 204 MeV, corresponding respectively to ranges in water of 10 cm and 27 cm from a Mevion S250 double scatter system unit were used. Electron energies of 6 and 20 MeV and photon energies of 6 and 18 MV from a Varian Clinac 21EX Linac were used. Two pieces of film (5×5 cm{sup 2}) were irradiated sequentially for doses of 100, 500, and 1000 cGy for all energies and modalities. Films were placed on the central beam axis for a 10×10 cm{sup 2} field size in the middle of spread out Bragg peak (SOBP) for proton and in respective dmax for photon and electron energies. Films were scanned on a flatbed Epson Expression 10000 XL scanner on the central region of the scanning window using 48-bit, 300 dpi, and landscape orientation after 48 hours post-irradiation of film to account for optical density (OD) stabilization. Film analysis of the red channel was performed using ImageJ 1.48v (National Institutes of Health). Results: The energy dependency of EBT3 among all energies and modalities for all doses studied was small within measurement uncertainties (1σ = ± 4.1%). The mean net OD in red channel for films receiving the same dose in the same energy modality had standard deviations within 0.9% for photons, 4.9% for electrons and 1.8% for protons. It was observed that film pieces were activated during proton irradiation, e.g., 7 mR/hr at surface after 30 minutes of irradiation, lasting for 2 hours post irradiation. Conclusion: EBT3 energy dependency was evaluated for clinically used proton, photon, and electron energies. The film self-activation may have contributed to fog and negligible dose.

Renewable energy resources

DEFF Research Database (Denmark)

Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

2014-01-01

Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

Directory of Open Access Journals (Sweden)

Shailendra Kumar

2013-06-01

Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

The influence of the spin-dependent phases of tunneling electrons on the conductance of a point ferromagnet/isolator/d-wave superconductor contact.

Science.gov (United States)

Vodopyanov, B P

2010-05-12

The influence of the spin-dependent phase shifts (SDPSs) associated with the electronic reflection and transmission amplitudes acquired by electrons upon scattering at the potential barrier on the Andreev reflection probability of electron and hole excitations for a ferromagnet/isolator/d-wave superconductor (FIS) contact and on the charge conductance of the FIS contact is studied. Various superconductor orientations are considered. It has been found that for strong ferromagnets and ultrathin interface potential for the {110} oriented d-wave superconductor the presence of the SDPS can lead to the appearance of finite-voltage peaks in the charge conductance of the F/I/d-wave superconductor contact. On the contrary, for the {100} orientation of the d-wave superconductor the presence of the SDPS can lead to restoration of the zero-voltage peak and suppression of finite-voltage peaks. The spin-dependent amplitudes of the Andreev reflection probability and energy levels of the spin-dependent Andreev bound states are found.

Effects of V-shaped edge defect and H-saturation on spin-dependent electronic transport of zigzag MoS2 nanoribbons

International Nuclear Information System (INIS)

Li, Xin-Mei; Long, Meng-Qiu; Cui, Li-Ling; Xiao, Jin; Zhang, Xiao-Jiao; Zhang, Dan; Xu, Hui

2014-01-01

Based on nonequilibrium Green's function in combination with density functional theory calculations, the spin-dependent electronic transport properties of one-dimensional zigzag molybdenum disulfide (MoS 2 ) nanoribbons with V-shaped defect and H-saturation on the edges have been studied. Our results show that the spin-polarized transport properties can be found in all the considered zigzag MoS 2 nanoribbons systems. The edge defects, especially the V-shaped defect on the Mo edge, and H-saturation on the edges can suppress the electronic transport of the systems. Also, the spin-filtering and negative differential resistance behaviors can be observed obviously. The mechanisms are proposed for these phenomena. - Highlights: • The spin-dependent electronic transport of zigzag MoS 2 nanoribbons. • The effects of V-shaped edge defect and H-saturation. • The effects of spin-filter and negative differential resistance can be observed

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.

The organisational performance of National Disability Sport Organisations during a time of austerity: A resource dependence theory perspective

OpenAIRE

Brown, Christopher; Pappous, Athanasios

2017-01-01

Austerity measures implemented by the UK Coalition government have had a negative impact on disabled people (Cross 2013). This article utilises the resource dependence theory to explore the challenges national disability sport organisations (NDSOs) have faced in their attempts to achieve growth, whilst discussing some of the tactics used to overcome these challenges. Secondary quantitative data from the 2011-2015 NDSO accounts was analysed, which suggests increased income has been accompanied...

Electron/electron acoustic instability

International Nuclear Information System (INIS)

Gary, S.P.

1987-01-01

The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2

International Nuclear Information System (INIS)

Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.

2005-01-01

X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature

Natural resources: A curse on education spending?

International Nuclear Information System (INIS)

Cockx, Lara; Francken, Nathalie

2016-01-01

In line with the rising interest in harnessing natural resource revenues for economic and human development through productive government investments, this paper aims to address an important blind spot in our understanding of the “resource curse” by contributing innovative insights on how natural resource wealth impacts government priorities and expenditure practices. Using a large panel dataset of 140 countries covering the period from 1995 to 2009, we find an adverse effect of resource dependence on public education expenditures relative to GDP that is robust to controlling for a range of additional covariates. Furthermore, our findings indicate that this resource curse effect on the government prioritization of education mainly stems from point-source natural resources. These results are of particular importance for the sustainable management of natural resource wealth in developing countries, as they could achieve especially high returns by investing resource revenues in public goods such as education. While this paper underlines the importance of institutions and government accountability, our findings also raise questions on the role of the private sector as a partner in development, as the extractives industry could consider increasing funding for education through Corporate Social Responsibility (CSR) initiatives. - Highlights: •We use a panel dataset of 140 countries covering the period from 1995 to 2009. •We find an inverse relationship between resource dependence and education spending. •The effect of resource dependence is robust to controlling for several covariates. •Indirect effects through a decline in accountability and the service industry. •This curse mainly stems from point-source resource dependence.

Dependence of synergy current driven by lower hybrid wave and electron cyclotron wave on the frequency and parallel refractive index of electron cyclotron wave for Tokamaks

International Nuclear Information System (INIS)

Huang, J.; Chen, S. Y.; Tang, C. J.

2014-01-01

The physical mechanism of the synergy current driven by lower hybrid wave (LHW) and electron cyclotron wave (ECW) in tokamaks is investigated using theoretical analysis and simulation methods in the present paper. Research shows that the synergy relationship between the two waves in velocity space strongly depends on the frequency ω and parallel refractive index N // of ECW. For a given spectrum of LHW, the parameter range of ECW, in which the synergy current exists, can be predicted by theoretical analysis, and these results are consistent with the simulation results. It is shown that the synergy effect is mainly caused by the electrons accelerated by both ECW and LHW, and the acceleration of these electrons requires that there is overlap of the resonance regions of the two waves in velocity space

Library usage patterns in the electronic information environment. Electronic journals, Use studies, Libraries, Medical libraries

Directory of Open Access Journals (Sweden)

B. Franklin

2004-01-01

Full Text Available This paper examines the methodology and results from Web-based surveys of more than 15,000 networked electronic services users in the United States between July 1998 and June 2003 at four academic health sciences libraries and two large main campus libraries serving a variety of disciplines. A statistically valid methodology for administering simultaneous Web-based and print-based surveys using the random moments sampling technique is discussed and implemented. Results from the Web-based surveys showed that at the four academic health sciences libraries, there were approximately four remote networked electronic services users for each in-house user. This ratio was even higher for faculty, staff, and research fellows at the academic health sciences libraries, where more than five remote users for each in-house user were recorded. At the two main libraries, there were approximately 1.3 remote users for each in-house user of electronic information. Sponsored research (grant funded research accounted for approximately 32% of the networked electronic services activity at the health sciences libraries and 16% at the main campus libraries. Sponsored researchers at the health sciences libraries appeared to use networked electronic services most intensively from on-campus, but not from in the library. The purpose of use for networked electronic resources by patrons within the library is different from the purpose of use of those resources by patrons using the resources remotely. The implications of these results on how librarians reach decisions about networked electronic resources and services are discussed.

The dependence of potential well formation on the magnetic field strength and electron injection current in a polywell device

International Nuclear Information System (INIS)

Cornish, S.; Gummersall, D.; Carr, M.; Khachan, J.

2014-01-01

A capacitive probe has been used to measure the plasma potential in a polywell device in order to observe the dependence of potential well formation on magnetic field strength, electron injection current, and polywell voltage bias. The effectiveness of the capacitive probe in a high energy electron plasma was determined by measuring the plasma potential of a planar diode with an axial magnetic field. The capacitive probe was translated along the axis of one of the field coils of the polywell, and the spatial profile of the potential well was measured. The confinement time of electrons in the polywell was estimated with a simple analytical model which used the experimentally observed potential well depths, as well as a simulation of the electron trajectories using particle orbit theory

Electronic resources of the rare books and valuable editions department of the Central Scientific Library of the V.N. Karazin Kharkiv National University: open access for research

Directory of Open Access Journals (Sweden)

І. К. Журавльова

2014-12-01

Full Text Available The article describes tasks that electronic collections of rare books fulfill: broad access for readers to rare and valuable editions providing, preservation of ensuring of the original. On the example of the electronic collection of the Central Scientific Library of the V.N. Karazin Kharkiv National University – «eScriptorium: electronic archive of rare books and manuscripts for research and education» the possibility of the full-text resources of the valuable editions using is shown. The principles of creation, structure, chronological frameworks, directions of adding the documents to the archive are represented. The perspectives of the project development are outlined as well as examples of the digital libraries of the European countries and Ukraine are provided, the actual task of preserving the originals of the rare books of the country is raised, the innovative approaches to serving users with electronic resources are considered. The evidences of cooperation of the Central Scientific Library of the V.N. Karazin Kharkiv National University with the largest world digital libraries: World Digital Library and Europeana are provided.

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

Effects of multiple electronic shells on strong-field multiphoton ionization and high-order harmonic generation of diatomic molecules with arbitrary orientation: An all-electron time-dependent density-functional approach

International Nuclear Information System (INIS)

Telnov, Dmitry A.; Chu, S.-I

2009-01-01

We present a time-dependent density-functional theory approach with proper long-range potential for an ab initio study of the effect of correlated multielectron responses on the multiphoton ionization (MPI) and high-order harmonic generation (HHG) of diatomic molecules N 2 and F 2 in intense short laser pulse fields with arbitrary molecular orientation. We show that the contributions of inner molecular orbitals to the total MPI probability can be sufficiently large or even dominant over the highest-occupied molecular orbital, depending on detailed electronic structure and symmetry, laser field intensity, and orientation angle. The multielectron effects in HHG are also very important. They are responsible for enhanced HHG at some orientations of the molecular axis. Even strongly bound electrons may have a significant influence on the HHG process.

Analytical local electron-electron interaction model potentials for atoms

International Nuclear Information System (INIS)

Neugebauer, Johannes; Reiher, Markus; Hinze, Juergen

2002-01-01

Analytical local potentials for modeling the electron-electron interaction in an atom reduce significantly the computational effort in electronic structure calculations. The development of such potentials has a long history, but some promising ideas have not yet been taken into account for further improvements. We determine a local electron-electron interaction potential akin to those suggested by Green et al. [Phys. Rev. 184, 1 (1969)], which are widely used in atom-ion scattering calculations, electron-capture processes, and electronic structure calculations. Generalized Yukawa-type model potentials are introduced. This leads, however, to shell-dependent local potentials, because the origin behavior of such potentials is different for different shells as has been explicated analytically [J. Neugebauer, M. Reiher, and J. Hinze, Phys. Rev. A 65, 032518 (2002)]. It is found that the parameters that characterize these local potentials can be interpolated and extrapolated reliably for different nuclear charges and different numbers of electrons. The analytical behavior of the corresponding localized Hartree-Fock potentials at the origin and at long distances is utilized in order to reduce the number of fit parameters. It turns out that the shell-dependent form of Green's potential, which we also derive, yields results of comparable accuracy using only one shell-dependent parameter

Size-dependent giant-magnetoresistance in millimeter scale GaAs/AlGaAs 2D electron devices

Science.gov (United States)

Mani, R. G.

2013-01-01

Large changes in the electrical resistance induced by the application of a small magnetic field are potentially useful for device-applications. Such Giant Magneto-Resistance (GMR) effects also provide new insights into the physical phenomena involved in the associated electronic transport. This study examines a “bell-shape” negative GMR that grows in magnitude with decreasing temperatures in mm-wide devices fabricated from the high-mobility GaAs/AlGaAs 2-Dimensional Electron System (2DES). Experiments show that the span of this magnetoresistance on the magnetic-field-axis increases with decreasing device width, W, while there is no concurrent Hall resistance, Rxy, correction. A multi-conduction model, including negative diagonal-conductivity, and non-vanishing off-diagonal conductivity, reproduces experimental observations. The results suggest that a size effect in the mm-wide 2DES with mm-scale electron mean-free-paths is responsible for the observed “non-ohmic” size-dependent negative GMR. PMID:24067264

Circularly polarized harmonic generation by intense bicircular laser pulses: electron recollision dynamics and frequency dependent helicity

Science.gov (United States)

Bandrauk, André D.; Mauger, François; Yuan, Kai-Jun

2016-12-01

Numerical solutions of time-dependent Schrödinger equations for one and two electron cyclic molecules {{{H}}}nq+ exposed to intense bichromatic circularly polarized laser pulses of frequencies {ω }1 and {ω }2, such that {ω }1/{ω }2={n}1/{n}2 (integer) produce circularly polarized high order harmonics with a cut-off recollision maximum energy at and greater than the linear polarization law (in atomic units) {N}m{ω }1={I}p+3.17{U}p, where I p is the ionization potential and {U}p={(2{E}0)}2/4{ω }2 is the ponderomotive energy defined by the field E 0 (intensity I={{cE}}02/8π ) from each pulse and mean frequency ω =({ω }1+{ω }2)/2 . An electron recollision model in a rotating frame at rotating frequency {{Δ }}ω =({ω }1-{ω }2)/2 predicts this simple result as a result of recollision dynamics in a combination of bichromatic circularly polarized pulses. The harmonic helicities and their intensities are shown to depend on compatible symmetries of the net pulse electric fields with that of the molecules.

Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

International Nuclear Information System (INIS)

Silva, Cleber F.

2011-01-01

The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm 2 ; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1σ), and the energy dependence response, to the same doses, is better 3% (1σ) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

Energy Technology Data Exchange (ETDEWEB)

Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

2001-06-01

KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

Dependence of electron beam instability growth rates on the beam-plasma system parameters

International Nuclear Information System (INIS)

Strangeway, R.J.

1982-01-01

Electron beam instabilites are studied by using a simple model for an electron beam streaming through a cold plasma, the beam being of finite width perpendicular to the ambient magnetic field. Through considerations of finite geometry and the coldness of the beam and background plasma, an instability similar to the two stream instability is assumed to be the means for wave growth in the system. Having found the maximum growth rate for one set of beam-plasma system parameters, this maximum growth rate is traced as these parameters are varied. The parameters that describe the system are the beam velocity (v/sub b/), electron gyrofrequency to ambient electron plasma frequency ratio (Ω/sub e//ω/sub p/e), the beam to background number density ratio (n/sub b//n/sub a/), and the beam width (a). When Ω/sub e//ω/sub p/e>1, a mode with Ω/sub e/<ω<ω/sub u/hr is found to be unstable, where Ω is the wave frequency and ω/sub u/hr is the upper hybrid resonance frequency. For low values of n/sub b//n/sub a/ and Ω/sub e/<ω/sub p/e, this mode is still present with ω/sub p/e<ω<ω/sub u/hr. If the beam density is large, n/sub b//n/sub a/approx. =1, the instability occures for frequencies just above the electron gyrofrequency. This mode may well be that observed in laboratory plasma before the system undergoes the beam-plasma discharge. There is another instability present, which occurs for ωapprox. =ω/sub p/e. The growth rates for this mode, which are generally larger than those found for the ωapprox. =ωuhr mode, are only weakly dependent on Ω/sub d//ω/sub p/e. That this mode is not always observed in the laboratory implies that some factors not considered in the present theory suppress this mode, specifically, finite beam length

Water Resources

International Nuclear Information System (INIS)

Abira, M.A.

1997-01-01

Water is essential for life and ecological sustenance; its availability is essential component of national welfare and productivity.The country's socio-economic activities are largely dependent on the natural endowment of water resources. Kenya's water resources comprises of surface waters (rivers, lakes and wetlands) and ground water. Surface water forms 86% of total water resources while the rest is ground water Geological, topographical and climatic factors influence the natural availability and distribution of water with the rainfall distribution having the major influence. Water resources in Kenya are continuously under threat of depletion and quality degradation owing to rising population, industrialization, changing land use and settlement activities as well as natural changes. However, the anticipated climate change is likely to exacerbate the situation resulting in increased conflict over water use rights in particular, and, natural resource utilisation in general. The impacts of climate change on the water resources would lead to other impacts on environmental and socio-economic systems

Intensity dependent waiting time for strong electron trapping events in speckle stimulated raman scatter

Energy Technology Data Exchange (ETDEWEB)

Rose, Harvey [Los Alamos National Laboratory; Daughton, W [Los Alamos National Laboratory; Yin, L [Los Alamos National Laboratory

2009-01-01

The onset of Stimulated Raman scatter from an intense laser speckle is the simplest experimentally realizable laser-plasma-interaction environment. Despite this data and recent 3D particle simulations, the controlling mechanism at the onset of backscatter in the kinetic regime when strong electron trapping in the daughter Langmuir wave is a dominant nonlinearity is not understood. This paper explores the consequences of assuming that onset is controlled by large thermal fluctuations. A super exponential dependence of mean reflectivity on speckle intensity in the onset regime is predicted.

The composition dependence of magnetic, electronic and optical properties of Mn-doped SixGe1-x nanowires

Science.gov (United States)

Wei, Jianglin; Lan, Mu; Zhang, Xi; Xiang, Gang

2017-07-01

Mn-doped SixGe1-x nanowires (NWs) with different Ge concentrations have been studied by first-principles calculations. It is found that the spin dependent energy bands of the NWs show rich variations both in bandgap width and type (from indirect to direct) as the Ge concentration changes. The Mn-doped SixGe1-x NWs exhibit half-metallic characteristics for all Ge concentrations, and the ground states of the NWs are found to be ferromagnetic (FM). The net magnetization mapping and spin density of states calculations reveal that Mn 3d electrons have a strong hybridization effect with nearest Ge 4p electrons, which results in the Ge’s nontrivial contribution to the magnetic moment of the NWs. Further magnon dispersion studies show that the magnetic order stability of the NWs is influenced by Ge concentrations. Finally, the dependence of the optical properties of the magnetic NWs on the Ge concentration is demonstrated. Our results suggest that Mn-doped SixGe1-x NWs may be useful in spintronic and optoelectronic devices.

Electronic-property dependent interactions between tetracycline and graphene nanomaterials in aqueous solution.

Science.gov (United States)

He, Lin; Liu, Fei-Fei; Zhao, Mengyao; Qi, Zhen; Sun, Xuefei; Afzal, Muhammad Zaheer; Sun, Xiaomin; Li, Yanhui; Hao, Jingcheng; Wang, Shuguang

2018-04-01

Understanding the interactions between graphene nanomaterials (GNMs) and antibiotics in aqueous solution is critical to both the engineering applications of GNMs and the assessment of their potential impact on the fate and transport of antibiotics in the aquatic environment. In this study, adsorption of one common antibiotic, tetracycline, by graphene oxide (GO) and reduced graphene oxide (RGO) was examined with multi-walled carbon nanotubes (MWCNTs) and graphite as comparison. The results showed that the tetracycline adsorption capacity by the four selected carbonaceous materials on the unit mass basis followed an order of GO>RGO>MWCNTs>graphite. Upon normalization by surface area, graphite, RGO and MWCNTs had almost the same high tetracycline adsorption affinity while GO exhibited the lowest. We proposed π-electron-property dependent interaction mechanisms to explain the observed different adsorption behaviors. Density functional theory (DFT) calculations suggested that the oxygen-containing functional groups on GO surface reduced its π-electron-donating ability, and thus decreased the π-based interactions between tetracycline and GO surface. Comparison of adsorption efficiency at different pH indicated that electrostatic interaction also played an important role in tetracycline-GO interactions. Site energy analysis confirmed a highly heterogeneous distribution of the binding sites and strong tetracycline binding affinity of GO surface. Copyright © 2017. Published by Elsevier B.V.

The Biomedical Resource Ontology (BRO) to enable resource discovery in clinical and translational research.

Science.gov (United States)

Tenenbaum, Jessica D; Whetzel, Patricia L; Anderson, Kent; Borromeo, Charles D; Dinov, Ivo D; Gabriel, Davera; Kirschner, Beth; Mirel, Barbara; Morris, Tim; Noy, Natasha; Nyulas, Csongor; Rubenson, David; Saxman, Paul R; Singh, Harpreet; Whelan, Nancy; Wright, Zach; Athey, Brian D; Becich, Michael J; Ginsburg, Geoffrey S; Musen, Mark A; Smith, Kevin A; Tarantal, Alice F; Rubin, Daniel L; Lyster, Peter

2011-02-01

The biomedical research community relies on a diverse set of resources, both within their own institutions and at other research centers. In addition, an increasing number of shared electronic resources have been developed. Without effective means to locate and query these resources, it is challenging, if not impossible, for investigators to be aware of the myriad resources available, or to effectively perform resource discovery when the need arises. In this paper, we describe the development and use of the Biomedical Resource Ontology (BRO) to enable semantic annotation and discovery of biomedical resources. We also describe the Resource Discovery System (RDS) which is a federated, inter-institutional pilot project that uses the BRO to facilitate resource discovery on the Internet. Through the RDS framework and its associated Biositemaps infrastructure, the BRO facilitates semantic search and discovery of biomedical resources, breaking down barriers and streamlining scientific research that will improve human health. Copyright © 2010 Elsevier Inc. All rights reserved.

Exploring the Tilt-Angle Dependence of electron tunneling across Molecular junction of Self-Assembled Alkanethiols

DEFF Research Database (Denmark)

Frederiksen, Thomas; Munuera, C.; Ocal, C.

2009-01-01

Electronic transport mechanisms in molecular junctions are investigated by a combination of first-principles calculations and current−voltage measurements of several well-characterized structures. We study self-assembled layers of alkanethiols grown on Au(111) and form tunnel junctions...... for the longer molecular chains. Our calculations confirm the observed trends and explain them as a result of two mechanisms, namely, a previously proposed intermolecular tunneling enhancement as well as a hitherto overlooked tilt-dependent molecular gate effect....

Mineral resources

Digital Repository Service at National Institute of Oceanography (India)

Valsangkar, A.B.

(placers), biogenous (ooze, limestone) or chemogenous (phosphorites and polymetallic nodules) type. In recent years, hydrothermal deposits, cobalt crust and methane gas hydrates are considered as frontier resources. Their distribution depends upon proximity...

Electronic Recruitment at CERN

CERN Multimedia

2004-01-01

The Human Resources Department switches to electronic recruitment. From now on whenever you are involved in a recruitment action you will receive an e-mail giving you access to a Web folder. Inside you will find a shortlist of applications drawn up by the Human Resources Department. This will allow you to consult the folder, at the same time as everyone else involved in the recruitment process, for the vacancy you are interested in. This new electronic recruitment system, known as e-RT, will be introduced in a presentation given at 10 a.m. on 11 February in the Main Auditorium. Implemented by AIS (Administrative Information Services) and the Human Resources Department, e-RT will cover vacancies open in all of CERN's recruitment programmes. The electronic application system was initially made available to technical students in July 2003. By December it was extended to summer students, fellows, associates and Local Staff. Geraldine Ballet from the Recruitment Service prefers e-RT to mountains of paper! The Hu...

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.

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

Science.gov (United States)

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

Renewable material resource potential

NARCIS (Netherlands)

van Weenen, H.; Wever, R.; Quist, J.; Tukker, A.; Woudstra, J.; Boons, F.A.A.; Beute, N.

2010-01-01

Renewable material resources, consist of complex systems and parts. Their sub-systems and sub-sub-systems, have unique, specific, general and common properties. The character of the use that is made of these resources, depends on the availability of knowledge, experience, methods, tools, machines

Resources and Transaction Costs

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

2004-01-01

resources depends on the propertyrights that she holds to those resources and on the transaction costs of exchanging,defining and protecting the relevant property rights. While transaction costs aremajor sources of value dissipation, value may be created by reducing suchdissipation. Implications for the RBV...

State-dependent electron delocalization dynamics at the solute-solvent interface: soft-x-ray absorption spectroscopy and ab initio calculations.

Science.gov (United States)

Bokarev, Sergey I; Dantz, Marcus; Suljoti, Edlira; Kühn, Oliver; Aziz, Emad F

2013-08-23

Nonradiative decay channels in the L-edge fluorescence yield spectra from transition-metal-aqueous solutions give rise to spectral distortions with respect to x-ray transmission spectra. Their origin is unraveled here using partial and inverse partial fluorescence yields on the microjet combined with multireference ab initio electronic structure calculations. Comparing Fe2+, Fe3+, and Co2+ systems we demonstrate and quantify unequivocally the state-dependent electron delocalization within the manifold of d orbitals as one origin of this observation.

Time-dependent plasma behavior triggered by a pulsed electron gun under conditions of beam-plasma-discharge

International Nuclear Information System (INIS)

Szuszczewicz, E.P.; Lin, C.S.

1982-01-01

This chapter reports on experiments whose purpose was to simulate spaceborne applications of energetic electron guns while exploring the ''in situ'' diagnostics of time-dependent beam-plasma behavior under pulsed electron gun conditions. Beam-plasma-discharge (BPD), the BPD afterglow that exists after gun-pulse termination, and the plasma decay process are considered. It is concluded that there is a rapid enhancement in plasma density as the gas turns on; that during the pulse-ON time a quasi-steady-state BPD can be maintained with characteristics identical with its dc counterpart; that in the period immediately following gun-pulse termination the plasma loss process is dominated by cross-field radial diffusion; and that the afterglow plasma is within + or -10% of being an isodensity contour

Merge of terminological resources

DEFF Research Database (Denmark)

Henriksen, Lina; Braasch, Anna

2012-01-01

In our globalized world, the amount of cross-national communication increases rapidly, which also calls for easy access to multi-lingual high quality terminological resources. Sharing of terminology resources is currently becoming common practice, and efficient strategies for integration...... – or merging – of terminology resources are strongly needed. This paper discusses prerequisites for successful merging with the focus on identification of candidate duplicates of a subject domain found in the resources to be merged, and it describes automatic merging strategies to be applied to such duplicates...... in electronic terminology resources. Further, some perspectives of manual, supplementary assessment methods supporting the automatic procedures are sketched. Our considerations are primarily based on experience gained in the IATE and EuroTermBank projects, as merging was a much discussed issue in both projects....

Angular dependent transport of auroral electrons in the upper atmosphere

International Nuclear Information System (INIS)

Lummerzheim, D.; Rees, M.H.

1989-01-01

The transport of auroral electrons through the upper atmosphere is analyzed. The transport equation is solved using a discrete ordinate method including elastic and inelastic scattering of electrons resulting in changes of pitch angle, and degradation in energy as the electrons penetrate into the atmosphere. The transport equation is solved numerically for the electron intensity as a function of altitude, pitch angle, and energy. In situ measurements of the pitch angle and energy distribution of precipitating electrons over an auroral arc provide boundary conditions for the calculation. The electron spectra from various locations over the aurora present a variety of anisotropic pitch angle distributions and energy spectra. Good agreement is found between the observed backscattered electron energy spectra and model predictions. Differences occur at low energies (below 500 eV) in the structure of the pitch angle distribution. Model calculations were carried out with various different phase functions for elastic and inelastic collisions to attempt changing the angular scattering, but the observed pitch angle distributions remain unexplained. We suggest that mechanisms other than collisional scattering influence the angular distribution of auroral electrons at or below 300 km altitude in the low energy domain. (author)

Complete electronics self-teaching guide with projects

CERN Document Server

Boysen, Earl

2012-01-01

An all-in-one resource on everything electronics-related! For almost 30 years, this book has been a classic text for electronics enthusiasts. Now completely updated for today's technology, this latest version combines concepts, self-tests, and hands-on projects to offer you a completely repackaged and revised resource. This unique self-teaching guide features easy-to-understand explanations that are presented in a user-friendly format to help you learn the essentials you need to work with electronic circuits. All you need is a general understanding of electronics concepts such as Oh

Work function and temperature dependence of electron tunneling through an N-type perylene diimide molecular junction with isocyanide surface linkers.

Science.gov (United States)

Smith, Christopher E; Xie, Zuoti; Bâldea, Ioan; Frisbie, C Daniel

2018-01-18

Conducting probe atomic force microscopy (CP-AFM) was employed to examine electron tunneling in self-assembled monolayer (SAM) junctions. A 2.3 nm long perylene tetracarboxylic acid diimide (PDI) acceptor molecule equipped with isocyanide linker groups was synthesized, adsorbed onto Ag, Au and Pt substrates, and the current-voltage (I-V) properties were measured by CP-AFM. The dependence of the low-bias resistance (R) on contact work function indicates that transport is LUMO-assisted ('n-type behavior'). A single-level tunneling model combined with transition voltage spectroscopy (TVS) was employed to analyze the experimental I-V curves and to extract the effective LUMO position ε l = E LUMO - E F and the effective electronic coupling (Γ) between the PDI redox core and the contacts. This analysis revealed a strong Fermi level (E F ) pinning effect in all the junctions, likely due to interface dipoles that significantly increased with increasing contact work function, as revealed by scanning Kelvin probe microscopy (SKPM). Furthermore, the temperature (T) dependence of R was found to be substantial. For Pt/Pt junctions, R varied more than two orders of magnitude in the range 248 K tunneling mechanism and allow independent determination of ε l , giving values compatible with estimates of ε l based on analysis of the full I-V data. Theoretical analysis revealed a general criterion to unambiguously rule out a two-step transport mechanism: namely, if measured resistance data exhibit a pronounced Arrhenius-type temperature dependence, a two-step electron transfer scenario should be excluded in cases where the activation energy depends on contact metallurgy. Overall, our results indicate (1) the generality of the Fermi level pinning phenomenon in molecular junctions, (2) the utility of employing the single level tunneling model for determining essential electronic structure parameters (ε l and Γ), and (3) the importance of changing the nature of the contacts to

Direct observation and theory of trajectory-dependent electronic energy losses in medium-energy ion scattering.

Science.gov (United States)

Hentz, A; Parkinson, G S; Quinn, P D; Muñoz-Márquez, M A; Woodruff, D P; Grande, P L; Schiwietz, G; Bailey, P; Noakes, T C Q

2009-03-06

The energy spectrum associated with scattering of 100 keV H+ ions from the outermost few atomic layers of Cu(111) in different scattering geometries provides direct evidence of trajectory-dependent electronic energy loss. Theoretical simulations, combining standard Monte Carlo calculations of the elastic scattering trajectories with coupled-channel calculations to describe inner-shell ionization and excitation as a function of impact parameter, reproduce the effects well and provide a means for far more complete analysis of medium-energy ion scattering data.

The calibration of spectrometers for Auger electron and X-ray photoelectron spectrometers part II - the determination of the electron spectrometer transmission function and the detector sensitivity energy dependencies

International Nuclear Information System (INIS)

Smith, G.C.; Seah, M.P.

1991-01-01

For the use of published general or theoretical sensitivity factors in quantitative AES and XPS the energy dependence of both the spectrometer transmission function and the detector sensitivity must be known. Here we develop simple procedures which allow these dependencies to be determined experimentally. Detailed measurements for a modified VG Scientific ESCALAB II, the metrology spectrometer, operated in both the constant ΔE/E and constant ΔE modes, are presented and compared with theoretical estimates. It is shown that an exceptionally detailed electron-optical calculation, involving proprietary information, would be required to match the accuracy of the experimental procedures developed. Removal of the spectrometer transmission function and the detector sensitivity terms allows the measured spectrum to be converted to the true electron emission spectrum irrespective of the mode of operation. This provides the first step to the provision of reference samples to calibrate the transmission functions and detector sensitivities of all instruments so that they, in turn, may produce true electron emission spectra. This is vital if (i) all instruments are to give consistent results, (ii) theoretical terms are to be used in quantifying either AES or XPS and (iii) reference data banks are to be established for AES or XPS

Impact-parameter dependence of the total probability for electromagnetic electron-positron pair production in relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Hencken, K.; Trautmann, D.; Baur, G.

1995-01-01

We calculate the impact-parameter-dependent total probability P total (b) for the electromagnetic production of electron-positron pairs in relativistic heavy-ion collisions in lowest order. We study expecially impact parameters smaller than the Compton wavelength of the electron, where the equivalent-photon approximation cannot be used. Calculations with and without a form factor for the heavy ions are done; the influence is found to be small. The lowest-order results are found to violate unitarity and are used for the calculation of multiple-pair production probabilities with the help of the approximate Poisson distribution already found in earlier publications

Electron beam effects in auger electron spectroscopy and scanning electron microscopy

International Nuclear Information System (INIS)

Fontaine, J.M.; Duraud, J.P.; Le Gressus, C.

1979-01-01

Electron beam effects on Si(100) and 5% Fe/Cr alloy samples have been studied by measurements of the secondary electron yield delta, determination of the surface composition by Auger electron spectroscopy and imaging with scanning electron microscopy. Variations of delta as a function of the accelerating voltage Esub(p) (0.5 -9 Torr has no effect on technological samples covered with their reaction layers; the sensitivities to the beam depend rather on the earlier mechanical, thermal and chemical treatment of the surfaces. (author)

Effective electron-electron and electron-phonon interactions in the Hubbard-Holstein model

International Nuclear Information System (INIS)

Aprea, G.; Di Castro, C.; Grilli, M. . E-mail marco.grilli@roma1.infn.it; Lorenzana, J.

2006-01-01

We investigate the interplay between the electron-electron and the electron-phonon interaction in the Hubbard-Holstein model. We implement the flow-equation method to investigate within this model the effect of correlation on the electron-phonon effective coupling and, conversely, the effect of phonons in the effective electron-electron interaction. Using this technique we obtain analytical momentum-dependent expressions for the effective couplings and we study their behavior for different physical regimes. In agreement with other works on this subject, we find that the electron-electron attraction mediated by phonons in the presence of Hubbard repulsion is peaked at low transferred momenta. The role of the characteristic energies involved is also analyzed

Electron nature of chemically active state of spiropyran with nitro group. Dependence of efficiency of radiation colouring of spiropyrans on their structure

International Nuclear Information System (INIS)

Kholmanskij, A.S.; Zubkov, A.V.; Dyumaev, K.M.

1980-01-01

Using the theory of solvatochromy it is shown that chemically active state of spiropyran with nitro group is its highly polar electron-excitated state. On the basis of the image on the electron nature of chemically active state of spiropyran the dependence of the values of radiation yield of the coloured forms of spiropyrans upon their structure is explained

Oscillator clustering in a resource distribution chain

DEFF Research Database (Denmark)

Postnov, D.; Sosnovtseva, Olga; Mosekilde, Erik

2005-01-01

separate the inherent dynamics of the individual oscillator from the properties of the coupling network. Illustrated by examples from microbiological population dynamics, renal physiology, and electronic oscillator theory, we show how competition for primary resources in a resource distribution chain leads...

Reply to the Discussion of Space-Time Modelling with Long-Memory Dependence: Assessing Ireland’s Wind Resource

Science.gov (United States)

1988-10-01

meteorologists’ rule-of-thumb that climatic drift manifests itself in periods greater than 30 years. For a fractionally-differenced model with our...estimates in a univariate ARIMA (p, d, q) with I d I< 0.5 has been derived by Li and McLrjd (1986). The model used by I-Iaslett an Raftery can be viewed as...Reply to the Discussion of "Space-time Modelling with Long-mnmory cDependence: Assessing Ireland’s Wind Resource" cJohn Haslett Department of

Power Electronics

DEFF Research Database (Denmark)

Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

2008-01-01

is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

International Nuclear Information System (INIS)

Kupfer, T.

1977-02-01

The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

Hybrid Vlasov–Fokker–Planck–Maxwell simulations of fast electron transport and the time dependance of K-shell excitation in a mid-Z metallic target

International Nuclear Information System (INIS)

Thomas, A G R; Sherlock, M; Ridgers, C P; Kuranz, C; Drake, R P

2013-01-01

Using a hybrid Vlasov–Fokker–Planck–Maxwell code coupled to calculations using a modified relativistic binary-encounter Bethe model of ionizing collisions we study the time and space dependence of K α photon generation by a fast electron beam injected into a solid density copper plasma target. The electron beam is chosen to be representative of that expected to be generated by a picosecond duration, ∼10 19 W cm −2 intensity laser. K α photons are produced as electrons reflux laterally across the target and are slowed and thermalized by collisions with, and Ohmic heating of, the background fluid over a ∼10 ps timescale, which dictates the timescale for K α emission. The results show reasonable agreement with recent experimental results in terms of both the yield and time dependance. We show how lateral expansion of the electrons can be imaged in the K α radiation. (paper)

Molecular tilt-dependent and tyrosine-enhanced electron transfer across ITO/SAM/[DPPC–Au NP–Tyrosine] Janus nanoparticle junction

Energy Technology Data Exchange (ETDEWEB)

Sarangi, Nirod Kumar; Patnaik, Archita, E-mail: archita59@yahoo.com [Indian Institute of Technology Madras, Department of Chemistry (India)

2016-09-15

Enhanced interfacial electron transfer (ET) across the otherwise insulating indium tin oxide/alkanethiol self-assembled monolayer (SAM)/redox molecule junction was accomplished when a Janus gold nanoparticle (JNP) protected by bioinspired phosphatidylcholine (DPPC) lipid and tyrosine amino acid ligands was anchored on it. In addition to the most theoretical and experimental investigations on the distance-dependent ET across Metal–Organic SAM–Nanoparticle (NP) architectures, the current results succinctly illustrate molecular tilt angle of the SAM and the characteristic of JNP as key factors in expediting the ET rate via electron tunneling. In the absence of JNP, electron tunneling with a tunneling factor β = 1.1 Å{sup −1} across the SAM was the rate-limiting step, evidenced from electrochemical impedance spectroscopy (EIS). The apparent electron transfer rate constant (k{sub app}{sup 0}) for anchored SAM was enhanced by at least one order of magnitude than the DPPC-only protected nanoparticle, suggesting the potential role of tyrosine towards the enhanced ET. The asymmetric and biogenic nature of the construct sheds light on a potential bioelectronic device for novel electronic attributes.Graphical abstractEntry of TOC .

Electron dose rate and photon contamination in electron arc therapy

International Nuclear Information System (INIS)

Pla, M.; Podgorsak, E.B.; Pla, C.

1989-01-01

The electron dose rate at the depth of dose maximum dmax and the photon contamination are discussed as a function of several parameters of the rotational electron beam. A pseudoarc technique with an angular increment of 10 degrees and a constant number of monitor units per each stationary electron field was used in our experiments. The electron dose rate is defined as the electron dose at a given point in phantom divided by the number of monitor units given for any one stationary electron beam. For a given depth of isocenter di the electron dose rates at dmax are linearly dependent on the nominal field width w, while for a given w the dose rates are inversely proportional to di. The dose rates for rotational electron beams with different di are related through the inverse square law provided that the two beams have (di,w) combinations which give the same characteristic angle beta. The photon dose at the isocenter depends on the arc angle alpha, field width w, and isocenter depth di. For constant w and di the photon dose at isocenter is proportional to alpha, for constant alpha and w it is proportional to di, and for constant alpha and di it is inversely proportional to w. The w and di dependence implies that for the same alpha the photon dose at the isocenter is inversely proportional to the electron dose rate at dmax

Positive Perceptions of Access to Online Library Resources Correlates with Quality and Quantity of Scholarly Publications among Finnish Academics. A Review of: Vakkari, Pertti. “Perceived Influence of the Use of Electronic Information Resources on Scholarly Work and Publication Productivity.” Journal of the American Society for Information Science and Technology 59.4 (Feb. 15, 2008: 602-12.

Directory of Open Access Journals (Sweden)

Scott Marsalis

2008-12-01

Full Text Available Objective – To investigate the relationship between academics’ use of library electronic resources and their opinions regarding how these resources have impacted their work, and to investigate the association between this perceived influence and publication productivity during the previous two years.Design – Two specific questions added to an annual online user-survey questionnaire; additional data mined from surveySetting – Twenty-two Finnish Universities served by FinELib, the Finnish Electronic Library.Subjects – Seven hundred and sixty seven academic staff and full-time doctoral students.Methods – A questionnaire was posted in April 2007 on FinELib’s homepage and advertised on each university library’s mainpage, and focused on respondents’ experience in the previous two years. Participants selected answers either from a list of category choices, or, when measuring perceptions, by rating agreement with statements along a four-point scale. Controlled variables measured were the respondents’ academic position, their discipline, membership in a research group, whether their literature use was discipline-specific or interdisciplinary, and their perception of the availability online of the relevant core literature. The independent variable measured was the scholars’ perception of the impact of the use of electronic library resources on their work. The dependent variable measured was the scholars’ self-reported publications in the two years preceding the survey.Main Results – Participants reported a positive impact on the efficiency of their work, most strongly in areas of ease of access, with lesser impacts in the range of materials available to them and the ease with which they can keep up-to-date in their field. To a lesser extent, the scholars perceived a positive impact on the quality of their work. Upon analysis, the study found that access to online library resources improved scholars’ work by the interconnected

Z1 dependence of ion-induced electron emission from aluminum

International Nuclear Information System (INIS)

Alonso, E.V.; Baragiola, R.A.; Ferron, J.; Jakas, M.M.; Oliva-Florio, A.

1980-01-01

We have measured the electron emission yields γ of clean aluminum under bombardment with H + , H 2 + , D + , D 2 + , He + , B + , C + , N + , N 2 + , O + , O 2 + , F + , Ne + , S + , Cl + , Ar + , Kr + , and Xe + in the energy range 1.2--50 keV. The clean surfaces were prepared by in situ evaporation of high-purity Al under ultra-high-vacuum conditions. It is found that kinetic electron emission yields γ/sub k/, obtained after subtracting from the measured γ a contribution due to potential emission, are roughly proportional to the electronic stopping powers, for projectiles lighter than Al. For heavier projectiles there is a sizable contribution to electron emission from collisions involving rapidly recoiling target atoms, which increases with the mass of the projectile, and which dominates the threshold and near-threshold behavior of kinetic emission. The results, together with recently reported data on Auger electron emission from ion-bombarded Al show that the mechanism proposed by Parilis and Kishinevskii of inner-shell excitation and subsequent Auger decay is negligible for light ions and probably small for heavy ions on Al and in our energy range. We thus conclude that kinetic electron emission under bombardment by low-energy ions results mainly from the escape of excited valence electrons

Electron-electron coincidence spectroscopies at surfaces

International Nuclear Information System (INIS)

Stefani, G.; Iacobucci, S.; Ruocco, A.; Gotter, R.

2002-01-01

In the past 20 years, a steadily increasing number of electron-electron coincidence experiments on atoms and molecules have contributed to a deeper understanding of electron-electron correlation effects. In more recent years this technique has been extended to the study of solid surfaces. This class of one photon IN two electrons OUT experiments will be discussed with an emphasis on grazing incidence geometry, that is expected to be particularly suited for studying surfaces. The crucial question of which is the dominant mechanism that leads to ejection of pairs of electron from the surface will be addressed. It will be shown that, depending on the kinematics chosen, the correlated behaviour of the pairs of electrons detected might be singled out from independent particle one

Electron beam-plasma interaction and electron-acoustic solitary waves in a plasma with suprathermal electrons

Science.gov (United States)

Danehkar, A.

2018-06-01

Suprathermal electrons and inertial drifting electrons, so called electron beam, are crucial to the nonlinear dynamics of electrostatic solitary waves observed in several astrophysical plasmas. In this paper, the propagation of electron-acoustic solitary waves (EAWs) is investigated in a collisionless, unmagnetized plasma consisting of cool inertial background electrons, hot suprathermal electrons (modeled by a κ-type distribution), and stationary ions. The plasma is penetrated by a cool electron beam component. A linear dispersion relation is derived to describe small-amplitude wave structures that shows a weak dependence of the phase speed on the electron beam velocity and density. A (Sagdeev-type) pseudopotential approach is employed to obtain the existence domain of large-amplitude solitary waves, and investigate how their nonlinear structures depend on the kinematic and physical properties of the electron beam and the suprathermality (described by κ) of the hot electrons. The results indicate that the electron beam can largely alter the EAWs, but can only produce negative polarity solitary waves in this model. While the electron beam co-propagates with the solitary waves, the soliton existence domain (Mach number range) becomes narrower (nearly down to nil) with increasing the beam speed and the beam-to-hot electron temperature ratio, and decreasing the beam-to-cool electron density ratio in high suprathermality (low κ). It is found that the electric potential amplitude largely declines with increasing the beam speed and the beam-to-cool electron density ratio for co-propagating solitary waves, but is slightly decreased by raising the beam-to-hot electron temperature ratio.

Diameter dependent electron transfer kinetics in semiconductor-enzyme complexes.

Science.gov (United States)

Brown, Katherine A; Song, Qing; Mulder, David W; King, Paul W

2014-10-28

Excited state electron transfer (ET) is a fundamental step for the catalytic conversion of solar energy into chemical energy. To understand the properties controlling ET between photoexcited nanoparticles and catalysts, the ET kinetics were measured for solution-phase complexes of CdTe quantum dots and Clostridium acetobutylicum [FeFe]-hydrogenase I (CaI) using time-resolved photoluminescence spectroscopy. Over a 2.0-3.5 nm diameter range of CdTe nanoparticles, the observed ET rate (kET) was sensitive to CaI concentration. To account for diameter effects on CaI binding, a Langmuir isotherm and two geometric binding models were created to estimate maximal CaI affinities and coverages at saturating concentrations. Normalizing the ET kinetics to CaI surface coverage for each CdTe diameter led to k(ET) values that were insensitive to diameter, despite a decrease in the free energy for photoexcited ET (ΔGET) with increasing diameter. The turnover frequency (TOF) of CaI in CdTe-CaI complexes was measured at several molar ratios. Normalization for diameter-dependent changes in CaI coverage showed an increase in TOF with diameter. These results suggest that k(ET) and H2 production for CdTe-CaI complexes are not strictly controlled by ΔG(ET) and that other factors must be considered.

Substrate dependence of electron-stimulated O - yields from dissociative electron attachment to physisorbed O2

Science.gov (United States)

Huels, M. A.; Parenteau, L.; Sanche, L.

1994-03-01

We present measurements of O- electron stimulated desorption yields obtained under identical experimental conditions from 0.15 monolayers (ML) of O2 deposited onto disordered substrates consisting of 4 ML of either Kr, Xe, C2H6, C2H4, N2O, CH3Cl, or H2O, all condensed on Pt (polycrystalline). The resulting O- yield functions, for incident electron energies below 20 eV, are compared to that obtained from the O2/Kr solid; this allows us to assess the order of magnitude effects of the local substrate environment on dissociative electron attachment (DEA) via the 2Πu and gas phase forbidden 2Σ+g,u resonances of O-2. We note that, in addition to electron energy losses in the substrate prior to DEA to O2 and post-dissociation interactions of the O- with the substrate molecules, charge or energy transfer from the O-2 transient anion to a substrate molecule, and capture of the incident electron into a dissociative anion resonance of the substrate molecule may contribute to a reduced O- yield from the physisorbed O2. In the case of O2 deposited on amorphous ice, we find that the O- signal from DEA to O2 is completely absent for electron energies below 14 eV; we attribute this to a complete quenching of the dissociative O-2(2Πu, 2Σ+) resonances by the adjacent water molecules.

Temperature dependences in electron-stimulated desorption of neutral europium

CERN Document Server

Ageev, V N; Madey, T E

2003-01-01

The electron-stimulated desorption (ESD) yield for neutral europium (Eu) atoms from Eu layers adsorbed on oxygen-covered tungsten surfaces has been measured as a function of electron energy, europium coverage and degree of oxidation of tungsten, with an emphasis on effects of substrate temperature. The measurements have been carried out using a time-of-flight method and surface ionization detector. We expand on an earlier report, and compare ESD of multivalent Eu with ESD of monovalent alkali atoms, studied previously. The Eu atom ESD is a complicated function of Eu coverage, electron energy and substrate temperature. In the coverage range 0.05-0.35 monolayer (ML), overlapping resonant-like Eu atom yield peaks are observed at electron energies E sub e of 36 and 41 eV that might be associated with Eu or W shallow core level excitations. Additional resonant-like peaks are seen at E sub e of 54 and 84 eV that are associated with W 5p and 5s level excitations. The Eu atom yield peaks at 36 and 41 eV are seen only...

Electronic conferencing for continuing medical education: a resource survey.

Science.gov (United States)

Sternberg, R J

1986-10-01

The use of electronic technologies to link participants for education conferences is an option for providers of Continuing Medical Education. In order to profile the kinds of electronic networks currently offering audio- or videoteleconferences for physician audiences, a survey was done during late 1985. The information collected included range of services, fees, and geographic areas served. The results show a broad diversity of providers providing both interactive and didactic programming to both physicians and other health care professionals.

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.

Wigner-like crystallization of Anderson-localized electron systems with low electron densities

CERN Document Server

Slutskin, A A; Pepper, M

2002-01-01

We consider an electron system under conditions of strong Anderson localization, taking into account interelectron long-range Coulomb repulsion. We establish that at sufficiently low electron densities and sufficiently low temperatures the Coulomb electron interaction brings about ordering of the Anderson-localized electrons into a structure that is close to an ideal (Wigner) crystal lattice, provided the dimension of the system is > 1. This Anderson-Wigner glass (AWG) is a new macroscopic electron state that, on the one hand, is beyond the conventional Fermi glass concept, and on the other hand, qualitatively differs from the known 'plain' Wigner glass (inherent in self-localized electron systems) in that the random slight electron displacements from the ideal crystal sites essentially depend on the electron density. With increasing electron density the AWG is found to turn into the plain Wigner glass or Fermi glass, depending on the width of the random spread of the electron levels. It is shown that the res...

A Ferredoxin- and F420H2-Dependent, Electron-Bifurcating, Heterodisulfide Reductase with Homologs in the Domains Bacteria and Archaea.

Science.gov (United States)

Yan, Zhen; Wang, Mingyu; Ferry, James G

2017-02-07

Heterodisulfide reductases (Hdr) of the HdrABC class are ancient enzymes and a component of the anaerobic core belonging to the prokaryotic common ancestor. The ancient origin is consistent with the widespread occurrence of genes encoding putative HdrABC homologs in metabolically diverse prokaryotes predicting diverse physiological functions; however, only one HdrABC has been characterized and that was from a narrow metabolic group of obligate CO 2 -reducing methanogenic anaerobes (methanogens) from the domain Archaea Here we report the biochemical characterization of an HdrABC homolog (HdrA2B2C2) from the acetate-utilizing methanogen Methanosarcina acetivorans with unusual properties structurally and functionally distinct from the only other HdrABC characterized. Homologs of the HdrA2B2C2 archetype are present in phylogenetically and metabolically diverse species from the domains Bacteria and Archaea The expression of the individual HdrA2, HdrB2, and HdrB2C2 enzymes in Escherichia coli, and reconstitution of an active HdrA2B2C2 complex, revealed an intersubunit electron transport pathway dependent on ferredoxin or coenzyme F 420 (F 420 H 2 ) as an electron donor. Remarkably, HdrA2B2C2 couples the previously unknown endergonic oxidation of F 420 H 2 and reduction of ferredoxin with the exergonic oxidation of F 420 H 2 and reduction of the heterodisulfide of coenzyme M and coenzyme B (CoMS-SCoB). The unique electron bifurcation predicts a role for HdrA2B2C2 in Fe(III)-dependent anaerobic methane oxidation (ANME) by M. acetivorans and uncultured species from ANME environments. HdrA2B2C2, ubiquitous in acetotrophic methanogens, was shown to participate in electron transfer during acetotrophic growth of M. acetivorans and proposed to be essential for growth in the environment when acetate is limiting. Discovery of the archetype HdrA2B2C2 heterodisulfide reductase with categorically unique properties extends the understanding of this ancient family beyond CO 2

Deviation from an inverse cosine dependence of kinetic secondary electron emission for angle of incidence at keV energy

International Nuclear Information System (INIS)

Ohya, Kaoru; Kawata, Jun; Mori, Ichiro

1989-01-01

Incident angle dependence of kinetic secondary electron emission from metals resulting from incidence of keV ions is investigated by computer simulation with the TRIM Monte Carlo program of ion scattering in matter. The results show large deviations from the inverse cosine dependence, which derives from high-energy approximation, because of a series of elastic collisions of incident ions with metal atoms. In the keV energy region, the elastic collisions have two different effects on the angular dependence for relatively high-energy light ions and for low-energy heavy ions: they result in over- and under-inverse-cosine dependences, respectively. The properties are observed even with an experiment of the keV-neutral incidence on a contaminated surface. In addition, the effects of the thin oxide layer and roughness on the surface are examined with simplified models. (author)

Phase transformation in multiferroic Bi5Ti3FeO15 ceramics by temperature-dependent ellipsometric and Raman spectra: An interband electronic transition evidence

Science.gov (United States)

Jiang, P. P.; Duan, Z. H.; Xu, L. P.; Zhang, X. L.; Li, Y. W.; Hu, Z. G.; Chu, J. H.

2014-02-01

Thermal evolution and an intermediate phase between ferroelectric orthorhombic and paraelectric tetragonal phase of multiferroic Bi5Ti3FeO15 ceramic have been investigated by temperature-dependent spectroscopic ellipsometry and Raman scattering. Dielectric functions and interband transitions extracted from the standard critical-point model show two dramatic anomalies in the temperature range of 200-873 K. It was found that the anomalous temperature dependence of electronic transition energies and Raman mode frequencies around 800 K can be ascribed to intermediate phase transformation. Moreover, the disappearance of electronic transition around 3 eV at 590 K is associated with the conductive property.

Characteristic of nicotine delivery devices – electronic cigarettes – as a tool to fight against tobacco dependence

Directory of Open Access Journals (Sweden)

A. Ye. Bogomolov

2018-04-01

Full Text Available The aim of the study is the analysis of specialized scientific literature and the review of data about the modern views on the electronic devices of nicotine delivery – electronic cigarettes from the view of evidence-based medicine. In recent years, electronic cigarettes (EC have become widespread. More than 10 years have passed since the first batch release of electronic cigarettes, and during that time, many studies have been conducted on various aspects of their use. However, the main concern of experts is the lack of a clear unanimous opinion about their health security and the EC's effectiveness as a method of tobacco control. The review presents modern data regarding existing EC modifications, the impact of their use on the human body at the cellular and systemic levels. Attention is paid to the fact that the actual physical nicotine dependence in the vast majority of cases is combined with psychological dependence, which reduces the effectiveness of other nicotine delivery devices. Data from randomized clinical trials show that further development of methods for studying the effects of the EC on the organism is very actual. In general, such studies were made to highlight key issues regarding the safety and effectiveness of e-cigarette use, including the fight against tobacco smoking. Special cautions were made to the research results that indicate the growing of popularity of e-cigarettes among teenagers, particularly in the US, Poland, Latvia, Finland and Korea. Conclusions. The EC has proven to be effective in removing of tobacco-related complaints, but so far, the EC cannot be available as safe and effective method to completely abandon smoking. Existing production regulations do not standardize either the EC itself or the liquid for them, because of which the composition (including the content of harmful to health substances is not actually regulated. In addition, there are no data about the long-term effects of EC usage, which is a

Utilization of bio-resources by low energy electron beam

International Nuclear Information System (INIS)

Kume, Tamikazu

2003-01-01

Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

Going beyond "it depends:" the role of context in shaping participation in natural resource management

Directory of Open Access Journals (Sweden)

Susan Baker

2018-03-01

Full Text Available Public participation is increasingly advocated in natural resource management to meet a spectrum of instrumental to normative goals. However, the success of participation in achieving these goals is highly variable, depending on both societal and institutional contexts. Whether participation realises its benefits or succumbs to its pitfalls is shaped by dynamic interactions operating among three contextual dimensions: participatory rationales (instrumental to normative, institutional fit of different levels (types of participation (information delivery to partnership to delegation, and social structures (such as cultural context, social capital, and power distribution. Some levels of participation may support the existing power hierarchy, others benefit organized stakeholder groups and special interests, and still others foster deliberative democratic outcomes. We argue that wise choice of levels of participation in particular contexts shapes the balance of participation's benefits and pitfalls.

The pressure dependence of structural, electronic, mechanical, vibrational, and thermodynamic properties of palladium-based Heusler alloys

Energy Technology Data Exchange (ETDEWEB)

Coban, Cansu [Balikesir Univ. (Turkey). Dept. of Physics

2017-07-01

The pressure dependent behaviour of the structural, electronic, mechanical, vibrational, and thermodynamic properties of Pd{sub 2}TiX (X=Ga, In) Heusler alloys was investigated by ab initio calculations. The lattice constant, the bulk modulus and its first pressure derivative, the electronic band structure and the density of states (DOS), mechanical properties such as elastic constants, anisotropy factor, Young's modulus, etc., the phonon dispersion curves and phonon DOS, entropy, heat capacity, and free energy were obtained under pressure. It was determined that the calculated lattice parameters are in good agreement with the literature, the elastic constants obey the stability criterion, and the phonon dispersion curves have no negative frequency which shows that the compounds are stable. The band structures at 0, 50, and 70 GPa showed valence instability at the L point which explains the superconductivity in Pd{sub 2}TiX (X=Ga, In).

Timing of reproduction in consumer-resource interactions

NARCIS (Netherlands)

Sun, Zepeng

2016-01-01

Timing of reproduction plays an important role in consumer-resource interactions, in particular when the development of the individuals is resource-dependent and when the resource productivity is changing over time. Despite its ubiquity in many species, seasonal reproduction is only to a limited

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.

Nonlinear electron-acoustic rogue waves in electron-beam plasma system with non-thermal hot electrons

Science.gov (United States)

Elwakil, S. A.; El-hanbaly, A. M.; Elgarayh, A.; El-Shewy, E. K.; Kassem, A. I.

2014-11-01

The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, non-thermal hot electrons obeying a non-thermal distribution, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles on the electron beam and energetic population parameter are discussed. The results of the present investigation may be applicable in auroral zone plasma.

Adaptation of mathematical educational content in e-learning resources

Directory of Open Access Journals (Sweden)

Yuliya V. Vainshtein

2017-01-01

Full Text Available Modern trends in the world electronic educational system development determine the necessity of adaptive learning intellectual environments and resources’ development and implementation. An upcoming trend in improvement the quality of studying mathematical disciplines is the development and application of adaptive electronic educational resources. However, the development and application experience of adaptive technologies in higher education is currently extremely limited and does not imply the usage flexibility. Adaptive educational resources in the electronic environment are electronic educational resources that provide the student with a personal educational space, filled with educational content that “adapts” to the individual characteristics of the students and provides them with the necessary information.This article focuses on the mathematical educational content adaptation algorithms development and their implementation in the e-learning system. The peculiarity of the proposed algorithms is the possibility of their application and distribution for adaptive e-learning resources construction. The novelty of the proposed approach is the three-step content organization of the adaptive algorithms for the educational content: “introductory adaptation of content”, “the current adaptation of content”, “estimative and a corrective adaptation”. For each stage of the proposed system, mathematical algorithms for educational content adaptation in adaptive e-learning resources are presented.Due to the high level of abstraction and complexity perception of mathematical disciplines, educational content is represented in the various editions of presentation that correspond to the levels of assimilation of the course material. Adaptation consists in the selection of the optimal edition of the material that best matches the individual characteristics of the student. The introduction of a three-step content organization of the adaptive

Note: Theoretical study on the gas pressure dependence of x-ray yield in TE111 cavity based electron cyclotron resonance x-ray source

International Nuclear Information System (INIS)

Selvakumaran, T. S.; Sen, Soubhadra; Baskaran, R.

2014-01-01

Adopting Langevin methodology, a pressure dependent frictional force term which represents the collisional effect is added to the Lorentz equation. The electrons are assumed to be starting from the uniformly distributed co-ordinates on the central plane. The trajectory of each electron is numerically simulated by solving the modified Lorentz equation for a given pressure. The Bremsstrahlung x-ray energy spectrum for each electron crossing the cavity wall boundary is obtained using the Duane-Hunt law. The total x-ray yield is estimated by adding the spectral contribution of each electron. The calculated yields are compared with the experimental results and a good agreement is found

The impact of market and organizational characteristics on nursing care facility service innovation: a resource dependency perspective.

Science.gov (United States)

Banaszak-Holl, J; Zinn, J S; Mor, V

1996-04-01

Using resource dependency theory as a conceptual framework, this study investigates both the organizational and environmental factors associated with an emerging health care service delivery innovation, the provision of specialty care in designated units in nursing care facilities. We consider two types of specialty units, Alzheimer's Disease and subacute care. The Medicare/Medicaid Automated Certification Survey (MMACS) data file was merged with local market area data obtained from the 1992 Area Resource File and with state level regulatory data. The likelihood of providing Alzheimer's Disease or subacute care in dedicated units was estimated by separate logistic regressions. Results indicate that facilities with fewer Medicare patients are more likely to operate a dedicated Alzheimer's care unit, while facilities located in markets with a large HMO population and greater hospital supply are more likely to operate a subacute care unit. While competition among nursing homes, for the most part, is an incentive to innovate, greater regulatory stringency appears to constrain the development of specialty care units of both types. Finally, organizational characteristics (e.g., size and proprietary status) appear to be important enabling factors influencing the propensity to provide specialty care in dedicated units. Nursing care facilities are moving toward providing specialty care units partly as a response to a growing demand by resource providers and to maintain a competitive edge in tighter markets. Loosening regulation directed at cost containment would further encourage the development of specialty care but should be preceded by some evaluation of population needs for specialty care and the effectiveness of specialty care units.

Electron attachment cross sections obtained from electron attachment spectroscopy

International Nuclear Information System (INIS)

Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.

1988-01-01

Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)

Internet and Electronic Information Management

Science.gov (United States)

2004-12-01

centers to form consortia and share electronic information sources. Although traditional resource sharing arrangements encouraged competition rather...outside world, through public relations and through marketing information products or services, to its own competitive advantage (Davenport 1997: 193-217... electronic information sources are a challenge for electronic information managers. Libraries and information centers are no longer “the only game in town

Wavelength dependence of momentum-space images of low-energy electrons generated by short intense laser pulses at high intensities

International Nuclear Information System (INIS)

Maharjan, C M; Alnaser, A S; Litvinyuk, I; Ranitovic, P; Cocke, C L

2006-01-01

We have measured momentum-space images of low-energy electrons generated by the interaction of short intense laser pulses with argon atoms at high intensities. We have done this over a wavelength range from 400 to 800 nm. The spectra show considerable structure in both the energy and angular distributions of the electrons. Some, but not all, energy features can be identified as multi-photon resonances. The angular structure shows a regularity which transcends the resonant structure and may be due instead to diffraction. The complexity of the results defies easy model-dependent interpretations and invites full solutions to Schroedinger's equation for these systems

Interplay between electron-phonon and electron-electron interactions

International Nuclear Information System (INIS)

Roesch, O.; Gunnarsson, O.; Han, J.E.; Crespi, V.H.

2005-01-01

We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Washing-free heterogeneous immunosensor using proximity-dependent electron mediation between an enzyme label and an electrode.

Science.gov (United States)

Dutta, Gorachand; Kim, Sinyoung; Park, Seonhwa; Yang, Haesik

2014-05-06

Washing processes, essential in most heterogeneous labeled assays, have been a big hurdle in simplifying the detection procedure and reducing assay time. Nevertheless, less attention has been paid to washing-free heterogeneous labeled assays. We report a purely washing-free immunosensor that allows fast, sensitive, and single-step detection of prostate-specific antigen in serum with low interference. Proximity-dependent electron mediation of ferrocenemethanol (Fc) between an indium-tin oxide (ITO) electrode and a glucose-oxidase (GOx) label allows us to discriminate between a bound and an unbound label: a bound label offers faster electron mediation than an unbound one. The electrooxidation of Fc at a low applied potential (0.13 V vs Ag/AgCl) and a low electrocatalytic ITO electrode and the oxidation of l-ascorbic acid by l-ascorbate oxidase minimize the effect of the interfering species. With a high concentration of glucose (200 mM), the signal and background levels are hardly dependent on the glucose-concentration variation in the sample. The washing-free immunosensor can detect a concentration of ca. 1 pg/mL for mouse IgG in phosphate-buffered saline and a concentration of ca. 10 pg/mL for prostate-specific antigen spiked in female serum after an incubation period of 10 min. The concentrations measured with actual clinical serum samples are in good agreement with the concentrations measured with a commercial instrument, which renders the washing-free heterogeneous immunosensor appealing for practical use.

Dynamic models for distributed generation resources

Energy Technology Data Exchange (ETDEWEB)

Morched, A.S. [BPR Energie, Sherbrooke, PQ (Canada)

2010-07-01

Distributed resources can impact the performance of host power systems during both normal and abnormal system conditions. This PowerPoint presentation discussed the use of dynamic models for identifying potential interaction problems between interconnected systems. The models were designed to simulate steady state behaviour as well as transient responses to system disturbances. The distributed generators included directly coupled and electronically coupled generators. The directly coupled generator was driven by wind turbines. Simplified models of grid-side inverters, electronically coupled wind generators and doubly-fed induction generators (DFIGs) were presented. The responses of DFIGs to wind variations were evaluated. Synchronous machine and electronically coupled generator responses were compared. The system model components included load models, generators, protection systems, and system equivalents. Frequency responses to islanding events were reviewed. The study demonstrated that accurate simulations are needed to predict the impact of distributed generation resources on the performance of host systems. Advances in distributed generation technology have outpaced the development of models needed for integration studies. tabs., figs.

Phase transformation in multiferroic Bi5Ti3FeO15 ceramics by temperature-dependent ellipsometric and Raman spectra: An interband electronic transition evidence

International Nuclear Information System (INIS)

Jiang, P. P.; Duan, Z. H.; Xu, L. P.; Zhang, X. L.; Li, Y. W.; Hu, Z. G.; Chu, J. H.

2014-01-01

Thermal evolution and an intermediate phase between ferroelectric orthorhombic and paraelectric tetragonal phase of multiferroic Bi 5 Ti 3 FeO 15 ceramic have been investigated by temperature-dependent spectroscopic ellipsometry and Raman scattering. Dielectric functions and interband transitions extracted from the standard critical-point model show two dramatic anomalies in the temperature range of 200–873 K. It was found that the anomalous temperature dependence of electronic transition energies and Raman mode frequencies around 800 K can be ascribed to intermediate phase transformation. Moreover, the disappearance of electronic transition around 3 eV at 590 K is associated with the conductive property

A bias-tunable electron-spin filter based on a two-dimensional electron gas modulated by ferromagnetic-Schottky metal stripes

Energy Technology Data Exchange (ETDEWEB)

Lu Jianduo, E-mail: l_j316@163.co [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China); Li Yunbao; Yun Meijuan [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China); Zheng Wei [Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077 (China)

2011-03-28

We investigate the effect of the bias in an electron-spin filter based on a two-dimensional electron gas modulated by ferromagnetic-Schottky metal stripes. The numerical results show that the electron transmission and the conductance as well as the spin polarization are strongly dependent on the bias applied to the device. - Research highlights: We propose a bias-tunable electron-spin filter. The transmission and the conductance depend on the bias and the electron energy. The spin polarization depends on the bias and the electron energy. The results are helpful for making new types of bias-tunable spin filters.

Natural Resources and FDI in GCC Countries

OpenAIRE

Mohamed Mahjoub Elheddad

2016-01-01

Natural resources are a blessing for some countries to attract FDI but cursed for others. Existing literature argues the suggestion that resource-rich countries attract less FDI because of resource (oil) price volatility. This study examines that natural resources discourage FDI in GCC countries (the FDI-Natural resources curse hypothesis), using panel data analysis for six oil dependent countries during 1980-2013 and applying several econometrics techniques. The main findings of this paper i...

Energy relaxation and separation of a hot electron-hole pair in organic aggregates from a time-dependent wavepacket diffusion method

International Nuclear Information System (INIS)

Han, Lu; Liang, WanZhen; Zhao, Yi; Zhong, Xinxin

2014-01-01

The time-dependent wavepacket diffusive method [X. Zhong and Y. Zhao, J. Chem. Phys. 138, 014111 (2013)] is extended to investigate the energy relaxation and separation of a hot electron-hole pair in organic aggregates with incorporation of Coulomb interaction and electron-phonon coupling. The pair initial condition generated by laser pulse is represented by a Gaussian wavepacket with a central momentum. The results reveal that the hot electron energy relaxation is very well described by two rate processes with the fast rate much larger than the slow one, consistent with experimental observations, and an efficient electron-hole separation is accomplished accompanying the fast energy relaxation. Furthermore, although the extra energy indeed helps the separation by overcoming the Coulomb interaction, the width of initial wavepacket is much sensitive to the separation efficiency and the narrower wavepacket generates the more separated charges. This behavior may be useful to understand the experimental controversy of the hot carrier effect on charge separation

Electron transfer capacity dependence of quinone-mediated Fe(III) reduction and current generation by Klebsiella pneumoniae L17.

Science.gov (United States)

Li, Xiaomin; Liu, Liang; Liu, Tongxu; Yuan, Tian; Zhang, Wei; Li, Fangbai; Zhou, Shungui; Li, Yongtao

2013-06-01

Quinone groups in exogenous electron shuttles can accelerate extracellular electron transfer (EET) from bacteria to insoluble terminal electron acceptors, such as Fe(III) oxides and electrodes, which are important in biogeochemical redox processes and microbial electricity generation. However, the relationship between quinone-mediated EET performance and electron-shuttling properties of the quinones remains incompletely characterized. This study investigates the effects of a series of synthetic quinones (SQs) on goethite reduction and current generation by a fermenting bacterium Klebsiella pneumoniae L17. In addition, the voltammetric behavior and electron transfer capacities (ETCs) of SQ, including electron accepting (EAC) and donating (EDC) capacities, is also examined using electrochemical methods. The results showed that SQ can significantly increase both the Fe(III) reduction rates and current outputs of L17. Each tested SQ reversibly accepted and donated electrons as indicated by the cyclic voltammograms. The EAC and EDC results showed that Carmine and Alizarin had low relative capacities of electron transfer, whereas 9,10-anthraquinone-2,6-disulfonic acid (AQDS), 2-hydroxy-1,4-naphthoquinone (2-HNQ), and 5-hydroxy-1,4-naphthoquinone (5-HNQ) showed stronger relative ETC, and 9,10-anthraquinone-2-carboxylic acid (AQC) and 9,10-anthraquinone-2-sulfonic acid (AQS) had high relative ETC. Enhancement of microbial goethite reduction kinetics and current outputs by SQ had a good linear relationship with their ETC, indicating that the effectiveness of quinone-mediated EET may be strongly dependent on the ETC of the quinones. Therefore, the presence of quinone compounds and fermenting microorganisms may increase the diversity of microbial populations that contribute to element transformation in natural environments. Moreover, ETC determination of different SQ would help to evaluate their performance for microbial EET under anoxic conditions. Copyright © 2013 Elsevier

Availability of Electronic Resources for Service Provision in ...

African Journals Online (AJOL)

The study also revealed that majority of the University libraries have adequate basic infrastructure for effective electronic information services. ... acquired by the library are put into maximal use by the library clientele, thereby ensuring the achievement of the library's objective which is satisfying the users, information needs.

Field dependence of the electron drift velocity along the hexagonal axis of 4H-SiC

Energy Technology Data Exchange (ETDEWEB)

Ivanov, P. A., E-mail: Pavel.Ivanov@mail.ioffe.ru; Potapov, A. S.; Samsonova, T. P.; Grekhov, I. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

2016-07-15

The forward current–voltage characteristics of mesa-epitaxial 4H-SiC Schottky diodes are measured in high electric fields (up to 4 × 10{sup 5} V/cm) in the n-type base region. A semi-empirical formula for the field dependence of the electron drift velocity in 4H-SiC along the hexagonal axis of the crystal is derived. It is shown that the saturated drift velocity is (1.55 ± 0.05) × 10{sup 7} cm/s in electric fields higher than 2 × 10{sup 5} V/cm.

Dependence of the electron Langmuir wave damping on the angle of propagation in weakly ionized neon plasma

International Nuclear Information System (INIS)

Zigman, V.J.; Milic, B.S.

1995-01-01

The dependence of the attenuation of the longitudinal electron Langmuir waves (ω ∼ ω pe ), in collisional weakly ionized, non-magnetized, uniform and steady-state plasmas placed in external d.c. electric field, on the angle θ between the wave vector and the electron drift rvec u is studied on the ground of the kinetic theory and the linear perturbation technique. The collisionless and collisional contributions to the overall attenuation were evaluated separately, as it was shown previously that in certain instances the elastic e - n encounters (with collision frequency ν en , ν en much-lt ω pe ) may attenuate the Langmuir waves more efficiently than the Landau mechanism. More precisely, it was found that, for any fixed value of E 0 /n n , there exists a critical value of the ratio n n /X above which the collisional attenuation prevails

Exact solution of a coupled spin–electron linear chain composed of localized Ising spins and mobile electrons

International Nuclear Information System (INIS)

Čisárová, Jana; Strečka, Jozef

2014-01-01

Exact solution of a coupled spin–electron linear chain composed of localized Ising spins and mobile electrons is found. The investigated spin–electron model is exactly solvable by the use of a transfer-matrix method after tracing out the degrees of freedom of mobile electrons delocalized over a couple of interstitial (decorating) sites. The exact ground-state phase diagram reveals an existence of five phases with different number of mobile electrons per unit cell, two of which are ferromagnetic, two are paramagnetic and one is antiferromagnetic. We have studied in particular the dependencies of compressibility and specific heat on temperature and electron density. - Highlights: • A coupled spin–electron chain composed of Ising spins and mobile electrons is exactly solved. • Quantum paramagnetic, ferromagnetic and antiferromagnetic ground states are found. • A compressibility shows a non-monotonous dependence on temperature and electron density. • Thermal dependences of specific heat display two distinct peaks

Emotional Intelligence Research within Human Resource Development Scholarship

Science.gov (United States)

Farnia, Forouzan; Nafukho, Fredrick Muyia

2016-01-01

Purpose: The purpose of this study is to review and synthesize pertinent emotional intelligence (EI) research within the human resource development (HRD) scholarship. Design/methodology/approach: An integrative review of literature was conducted and multiple electronic databases were searched to find the relevant resources. Using the content…

Direct electrons at the CERN ISR. II. A study of the transverse momentum dependence above 0.6 GeV/c

International Nuclear Information System (INIS)

Buesser, F.W.; Camilleri, L.; Di Lella, L.

1975-01-01

The previously reported observation of direct electrons produced in proton-proton collisions at the CERN ISR was extended to transverse moments, p*/sub T/, as low as 0.6 GeV/c. The ratio of electron to pion cross sections seems to rise as p*/sub T/ is decreased. It increases by at most a factor of 2 between p*/sub T/ of 2 and 0.6 GeV/c. Results on the s-dependence of this ratio and on correlated charged particles are presented for p*/sub T/ greater than or equal to 1 GeV/c in another work

Communication: satisfying fermionic statistics in the modeling of open time-dependent quantum systems with one-electron reduced density matrices.

Science.gov (United States)

Head-Marsden, Kade; Mazziotti, David A

2015-02-07

For an open, time-dependent quantum system, Lindblad derived the most general modification of the quantum Liouville equation in the Markovian approximation that models environmental effects while preserving the non-negativity of the system's density matrix. While Lindblad's modification is correct for N-electron density matrices, solution of the Liouville equation with a Lindblad operator causes the one-electron reduced density matrix (1-RDM) to violate the Pauli exclusion principle. Consequently, after a short time, the 1-RDM is not representable by an ensemble N-electron density matrix (not ensemble N-representable). In this communication, we derive the necessary and sufficient constraints on the Lindbladian matrix within the Lindblad operator to ensure that the 1-RDM remains N-representable for all time. The theory is illustrated by considering the relaxation of an excitation in several molecules F2, N2, CO, and BeH2 subject to environmental noise.

Dissipative time-dependent quantum transport theory.

Science.gov (United States)

Zhang, Yu; Yam, Chi Yung; Chen, GuanHua

2013-04-28

A dissipative time-dependent quantum transport theory is developed to treat the transient current through molecular or nanoscopic devices in presence of electron-phonon interaction. The dissipation via phonon is taken into account by introducing a self-energy for the electron-phonon coupling in addition to the self-energy caused by the electrodes. Based on this, a numerical method is proposed. For practical implementation, the lowest order expansion is employed for the weak electron-phonon coupling case and the wide-band limit approximation is adopted for device and electrodes coupling. The corresponding hierarchical equation of motion is derived, which leads to an efficient and accurate time-dependent treatment of inelastic effect on transport for the weak electron-phonon interaction. The resulting method is applied to a one-level model system and a gold wire described by tight-binding model to demonstrate its validity and the importance of electron-phonon interaction for the quantum transport. As it is based on the effective single-electron model, the method can be readily extended to time-dependent density functional theory.

Alloy scattering dependence of electron transport in AlGaN

International Nuclear Information System (INIS)

Yarar, Z.; Ozdemir, M.

2010-01-01

The electron transport and velocity characteristics in AlGaN are examined using an ensemble Monte Carlo simulation method. A three valley band structure model where nonparabolicity effects are considered in all valleys is used for Monte Carlo calculations. All of the major electron scattering interactions like acoustic and optical phonon, intervaley, ionized impurity and alloy disorder scatterings are included in the calculations. The velocity-applied electric field characteristics are analyzed as a function of Al molar fraction and temperature in the ranges of x=0.1 to x=0.5 and 77 K to 500 K, respectively. The velocity overshoot is clearly observed and the population of valleys seems well-matched with the occupancy of valleys in AlGaN. The results of electron steady state velocity-field curves are found that the alloy disorder scattering has important effects on the electron transport characteristics of AlGaN.

Electron reactions in model liquids and biological systems

International Nuclear Information System (INIS)

Bakale, G.; Gregg, E.C.