Sample records for electronic discussion groups

  1. Exploration of the Value of Electronic Discourse for Developing Cultural Competency in College Freshmen

    ERIC Educational Resources Information Center

    Phillips, Donna Alley

    2010-01-01

    The purpose of this study was to explore the impact of electronic discourse on cultural competency growth among college students. Data were gathered by monitoring six discussion groups, three of which held face-to-face (FTF) discussions and three of which held electronic discussions (ED). Each group was led by a college professor after a…

  2. Improving Group Learning through Electronically Facilitated Skillful Discussions.

    ERIC Educational Resources Information Center

    Driver, Michaela

    2003-01-01

    Surveys, notes, and transcripts from 35 business administration students participating in group learning via chat rooms were analyzed. Qualitative and quantitative data indicated that electronic conferencing can effectively support groups in reflection, collective inquiry, and skillful discussion. (Contains 21 references.) (SK)

  3. Evaluation of electronic discussion groups as a teaching/learning strategy in an evidence-based medicine course: a pilot study.

    PubMed

    Kamin, C; Glicken, A; Hall, M; Quarantillo, B; Merenstein, G

    2001-01-01

    As course directors, we wished to incorporate small group learning into our Evidence-based Medicine course for students to get feedback on the development of a well constructed, researchable clinical question. Scheduling of these groups was problematic. We sought to evaluate computer-mediated communication as an alternative to face-to-face small groups. Students were randomly assigned to either face-to-face small groups or asynchronous, electronic, small groups. Final examination scores were analyzed with an analysis of variance to determine if there were differences in student performance based on group type. Student survey items were analyzed using Fisher's Exact test to determine if there were differences in student attitudes based on group type. There were no significant differences found in overall student performance. Significant differences in student attitudes were found to exist with respect to: (1) participation in discussions, with face-to-face groups reporting greater participation; (2) putting more thought into comments, with electronic groups reporting more thought put into comments; and (3) difficulty relating to other students in the class, with electronic groups reporting more difficulty. We found electronic discussion groups (computer-mediated communication) to be a viable teaching/learning strategy with no adverse effects on student performance or attitudes.

  4. It's About Time: Using Electronic Literature Discussion Groups with Adult Learners

    ERIC Educational Resources Information Center

    Beeghly, Dena G.

    2005-01-01

    The purpose of this study was to investigate the effect that participating in online literature discussions would have on the discourse and learning of adult students. Would electronic literature (e-lit) discussions promote grand conversations? Would students feel that e-lit discussions enhanced their understanding of what they read, and, if so,…

  5. Incorporating electronic-based and computer-based strategies: graduate nursing courses in administration.

    PubMed

    Graveley, E; Fullerton, J T

    1998-04-01

    The use of electronic technology allows faculty to improve their course offerings. Four graduate courses in nursing administration were contemporized to incorporate fundamental computer-based skills that would be expected of graduates in the work setting. Principles of adult learning offered a philosophical foundation that guided course development and revision. Course delivery strategies included computer-assisted instructional modules, e-mail interactive discussion groups, and use of the electronic classroom. Classroom seminar discussions and two-way interactive video conferencing focused on group resolution of problems derived from employment settings and assigned readings. Using these electronic technologies, a variety of courses can be revised to accommodate the learners' needs.

  6. Unblocking brainstorms.

    PubMed

    Gallupe, R B; Bastianutti, L M; Cooper, W H

    1991-02-01

    Brainstorming groups have consistently produced fewer ideas than have the equivalent number of individuals working by themselves. These results have been attributed to social loafing, evaluation apprehension, and production blocking in groups. In this study, a new brainstorming technique--electronic brainstorming--that may reduce both production blocking and evaluation apprehension was assessed. Electronic and nonelectronic groups and nominal and interacting groups were compared in a 2 x 2 factorial design. Electronic groups were more productive than nonelectronic groups, but the productivity of nominal and interacting groups did not differ. In contrast, interacting groups felt better about the idea-generation process than did nominal groups. Ways in which electronic brainstorming can reopen a long dormant area of research and application are discussed.

  7. Internet, World Wide Web, and Creativity.

    ERIC Educational Resources Information Center

    Siau, Keng

    1999-01-01

    This article presents the services available on the Internet for creativity and discusses their applicability to electronic brainstorming. Services include bulletin boards, electronic mail and listservs, chat groups, file transfers, and remote login. Opportunities provided by the World Wide Web are discussed, along with tools available to…

  8. Results of the Arizona Medicaid health information technology pharmacy focus groups.

    PubMed

    Warholak, Terri L; Murcko, Anita; McKee, Megan; Urbine, Terry

    2011-12-01

    In 2007, a federal Medicaid Transformation Grant was awarded to design, develop, and deploy a statewide Health Information Exchange and Electronic Health Record in Arizona, United States. To explore the health information technology needs, knowledge, and expectations of Arizona's health care professionals, moderated focus groups were conducted. This article describes the results of the pharmacist focus groups. Focus group activities included a brief presentation, completion of a paper-based survey, and group discussion. The methods included solicitation by invitation, participant selection, meeting content, collaterals, focus group execution, recording, analysis, and discerning comparability among groups. Pharmacy focus group discussions centered on electronic prescribing, including the anticipated advantages: reducing handwriting interpretation errors, improving formulary compliance, improving communication with prescribers, increasing efficiency, and ensuring data accuracy. Disadvantages included: medication errors, inadequate training and knowledge of software applications, and inflated patient expectations. Pharmacists ranked e-prescribing as the highest priority feature of an electronic health system. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Electronic Creativity Techniques for Organizational Innovation.

    ERIC Educational Resources Information Center

    Siau, Keng L.

    1996-01-01

    Discusses using advanced electronic and communication technology to improve organizational innovation. Group creativity techniques, such as electronic brainstorming, PMI (a brainstorming approach involving plus, minus, and interesting points), synectics, and their verbal counterparts are compared. Electronic PMI and synectics are found to be…

  10. Lead and uranium group abundances in cosmic rays

    NASA Technical Reports Server (NTRS)

    Yadav, J. S.; Perelygin, V. P.

    1985-01-01

    The importance of Lead and Uranium group abundances in cosmic rays is discussed in understanding their evolution and propagation. The electronic detectors can provide good charge resolution but poor data statistics. The plastic detectors can provide somewhat better statistics but charge resolution deteriorates. The extraterrestrial crystals can provide good statistics but with poor charge resolution. Recent studies of extraterrestrial crystals regarding their calibration to accelerated uranium ion beam and track etch kinetics are discussed. It is hoped that a charge resolution of two charge units can be achieved provided an additional parameter is taken into account. The prospects to study abundances of Lead group, Uranium group and superheavy element in extraterrestrial crystals are discussed, and usefulness of these studies in the light of studies with electronic and plastic detectors is assessed.

  11. Study of electron transport in the functionalized nanotubes and their impact on the electron transfer in the active site of horseradish peroxidase

    NASA Astrophysics Data System (ADS)

    Feizabadi, Mina; Ajloo, Davood; Soleymanpour, Ahmad; Faridnouri, Hassan

    2018-05-01

    Electrochemical characterization of functionalized carbon nanotubes (f-CNT) including carboxyl (CNT-COOH), amine (CNT-NH2) and hydroxyl (CNT-OH) functional groups were studied using differential pulse voltammetry (DPV). The current-voltage (I-V) curves were obtained from each system and the effect of f-CNT on redox interaction of horseradish peroxidase (HRP) immobilized on the electrode surface was investigated. The non-equilibrium Green's function (NEGF) combined with density functional theory (DFT) were used to study the transport properties of f-CNT. Additionally, the effect of the number of functional groups on transport properties of CNT, I-V characteristics, electronic transmission coefficients and spatial distribution of f-CNTs have been calculated and analyzed. The results showed that the carboxyl derivative has larger transmission coefficients and current value than other f-CNTs. Then, the effect of functional groups on the electron transport in heme group of HRP is discussed. Finally, the effect of a covalent bond between active site amino acids and amine functional group of CNT was investigated and discussed.

  12. The ethics of research using electronic mail discussion groups.

    PubMed

    Kralik, Debbie; Warren, Jim; Price, Kay; Koch, Tina; Pignone, Gino

    2005-12-01

    The aim of this paper is to identify and discuss the ethical considerations that have confronted and challenged the research team when researchers facilitate conversations using private electronic mail discussion lists. The use of electronic mail group conversations, as a collaborative data generation method, remains underdeveloped in nursing. Ethical challenges associated with this approach to data generation have only begun to be considered. As receipt of ethics approval for a study titled; 'Describing transition with people who live with chronic illness' we have been challenged by many ethical dilemmas, hence we believe it is timely to share the issues that have confronted the research team. These discussions are essential so we can understand the possibilities for research interaction, communication, and collaboration made possible by advanced information technologies. Our experiences in this study have increased our awareness for ongoing ethical discussions about privacy, confidentiality, consent, accountability and openness underpinning research with human participants when generating data using an electronic mail discussion group. We describe how we work at upholding these ethical principles focusing on informed consent, participant confidentiality and privacy, the participants as threats to themselves and one another, public-private confusion, employees with access, hackers and threats from the researchers. A variety of complex issues arise during cyberspace research that can make the application of traditional ethical standards troublesome. Communication in cyberspace alters the temporal, spatial and sensory components of human interaction, thereby challenging traditional ethical definitions and calling to question some basic assumptions about identity and ones right to keep aspects of it confidential. Nurse researchers are bound by human research ethics protocols; however, the nature of research by electronic mail generates moral issues as well as ethical concerns. Vigilance by researchers is required to ensure that data are viewed within the scope of the enabling ethics approval.

  13. Web Site Design Benchmarking within Industry Groups.

    ERIC Educational Resources Information Center

    Kim, Sung-Eon; Shaw, Thomas; Schneider, Helmut

    2003-01-01

    Discussion of electronic commerce focuses on Web site evaluation criteria and applies them to different industry groups in Korea. Defines six categories of Web site evaluation criteria: business function, corporate credibility, contents reliability, Web site attractiveness, systematic structure, and navigation; and discusses differences between…

  14. All-electron and relativistic pseudopotential studies for the group 1 element polarizabilities from K to element 119.

    PubMed

    Lim, Ivan S; Schwerdtfeger, Peter; Metz, Bernhard; Stoll, Hermann

    2005-03-08

    Two-component and scalar relativistic energy-consistent pseudopotentials for the group 1 elements from K to element 119 are presented using nine electrons for the valence space definition. The accuracy of such an approximation is discussed for dipole polarizabilities and ionization potentials obtained at the coupled-cluster level as compared to experimental and all-electron Douglas-Kroll results.

  15. The Tie that Binds: Building Discourse Communities and Group Cohesion through Computer-Based Conferences.

    ERIC Educational Resources Information Center

    Selfe, Cynthia L.; Eilola, J. Daniel

    1988-01-01

    Discussion of the use of electronic conferencing to form a discourse community focuses on a case study of student consultants working in a microcomputer lab supporting writing courses at Michigan Technological University. The formulation of a group identity, as well as group values, goals, and expectations are discussed. (16 references) (LRW)

  16. Electron guns and collectors developed at INP for electron cooling devices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharapa, A.N.; Shemyakin, A.V.

    1997-09-01

    Institute of Nuclear Physics (INP) has a rich experience in designing electron guns and collectors for electron cooling devices. This paper is a review of the experience of several INP research groups in this field. Some results obtained at INP for systems without a guiding magnetic field are also discussed.

  17. Functional conjugated pyridines via main-group element tuning.

    PubMed

    Stolar, Monika; Baumgartner, Thomas

    2018-03-29

    Pyridine-based materials have seen widespread attention for the development of n-type organic materials. In recent years, the incorporation of main-group elements has also explored significant advantages for the development and tunability of organic conjugated materials. The unique chemical and electronic structure of main-group elements has led to several enhancements in conventional organic materials. This Feature article highlights recent main-group based pyridine materials by discussing property enhancements and application in organic electronics.

  18. Raising the Standard. Electronics Technician Skills for Today and Tomorrow.

    ERIC Educational Resources Information Center

    Electronic Industries Foundation, Washington, DC.

    This manual identifies the standard skills required of a work-ready, entry-level electronics technician. It provides a valuable resource for these groups: students considering careers as electronics technicians; for counselors, educators, and administrators; and for employers. An introduction discusses use of the standards and includes two lists…

  19. Do electronic mail discussion lists act as virtual colleagues?

    PubMed Central

    Worth, E. R.; Patrick, T. B.

    1997-01-01

    Anesthesiology Discussion Group (ADG), an electronic mail (email) discussion list, has previously been shown to be a clinically oriented, cost-effective form of telemedicine. ADG is composed of an international collection of anesthesia providers. Discussions with colleagues are generally informal in nature and are examples of types of information-seeking behavior which frequently occur in hallways or lounges of a hospital or clinic. Information-seeking occurs when a health care provider searches for information which will be used to solve or satisfy a patient's problem or need. We surveyed practitioners who had previously submitted non-rhetorical, clinical questions to the group. After analysis of the questionnaire results, we conclude that ADG is a valuable resource used for information-seeking and is a clinically effective form of telemedicine. Many of the respondents indicated that they used ADG to obtain second opinions from the collective expertise of group members. Respondents also indicated that they were generally satisfied with the quality of responses and would not hesitate to use ADG for future clinical questions. PMID:9357641

  20. Examining the Effects of Electronic Mentoring Prompts on Learners' Scientific Reasoning Skills in a Text-Based Online Conference for a Science Education Course

    ERIC Educational Resources Information Center

    Angeli, Charoula; Valanides, Nicos

    2008-01-01

    In a science education methods course, groups of students were initially involved in a face-to-face discussion and were sensitized about certain conflicting claims regarding a puzzling observation or set of observations. They were then instructed to resolve their conflicting ideas through electronic discussion. Students had two weeks time to…

  1. The challenge of electronic health records (EHRs) design and implementation: responses of health workers to drawing a 'big and rich picture' of a future EHR programme using animated tools.

    PubMed

    Jenkings, K Neil; Wilson, Robert G

    2007-01-01

    To investigate the use of animation tools to aid visualisation of problems for discussion within focus groups, in the context of healthcare workers discussing electronic health records (EHRs). Ten healthcare staff focus groups, held in a range of organisational contexts. Each focus group was in four stages: baseline discussion, animator presentation, post-animator discussion and questionnaire. Audio recordings of the focus groups were transcribed and coded and the emergent analytic themes analysed for issues relating to EHR design and implementation. The data allowed a comparison of baseline and post-animator discussion. The animator facilitated discussion about EHR issues and these were thematically coded as: Workload; Sharing Information; Access to Information; Record Content; Confidentiality; Patient Consent; and Implementation. We illustrate that use of the animator in focus groups is one means to raise understanding about a proposed EHR development. The animator provided a visual 'probe' to support a more proactive and discursive localised approach to end-user concerns, which could be part of an effective stakeholder engagement and communication strategy crucial in any EHR or health informatics implementation programme. The results of the focus groups were to raise salient issues and concerns, many of which anticipated those that have emerged in the current NHS Connecting for Health Care Records programme in England. Potentially, animator-type technologies may facilitate the user ownership which other forms of dissemination appear to be failing to achieve.

  2. Electronic structures and population dynamics of excited states of xanthione and its derivatives

    NASA Astrophysics Data System (ADS)

    Fedunov, Roman G.; Rogozina, Marina V.; Khokhlova, Svetlana S.; Ivanov, Anatoly I.; Tikhomirov, Sergei A.; Bondarev, Stanislav L.; Raichenok, Tamara F.; Buganov, Oleg V.; Olkhovik, Vyacheslav K.; Vasilevskii, Dmitrii A.

    2017-09-01

    A new compound, 1,3-dimethoxy xanthione (DXT), has been synthesized and its absorption (stationary and transient) and luminescence spectra have been measured in n-hexane and compared with xanthione (XT) spectra. The pronounced broadening of xanthione vibronic absorption band related to the electronic transition to the second singlet excited state has been observed. Distinctions between the spectra of xanthione and its methoxy derivatives are discussed. Quantum chemical calculations of these compounds in the ground and excited electronic states have been accomplished to clarify the nature of electronic spectra changes due to modification of xanthione by methoxy groups. Appearance of a new absorption band of DXT caused by symmetry changes has been discussed. Calculations of the second excited state structure of xanthione and its methoxy derivatives confirm noticeable charge transfer (about 0.1 of the charge of an electron) from the methoxy group to thiocarbonyl group. Fitting of the transient spectra of XT and DXT has been fulfilled and the time constants of internal conversion S2 →S1 and intersystem crossing S1 →T1 have been determined. A considerable difference between the time constants of internal conversion S2 →S1 in XT and DXT is uncovered.

  3. Group Theory in Spectroscopy

    ERIC Educational Resources Information Center

    Mooney, A.

    1973-01-01

    Discusses application of group theory to the teaching of selection rules in electronic and vibrational spectroscopy. Indicates that acquaintance with such a mathematical concept is essential for high school students to understand molecular spectrum courses. (CC)

  4. Applications of biochar in redox-mediated reactions.

    PubMed

    Yuan, Yong; Bolan, Nanthi; Prévoteau, Antonin; Vithanage, Meththika; Biswas, Jayanta Kumar; Ok, Yong Sik; Wang, Hailong

    2017-12-01

    Biochar is chemically more reduced and reactive than the original feedstock biomass. Graphite regions, functional groups, and redox-active metals in biochar contribute to its redox characteristics. While the functional groups such as phenolic species in biochar are the main electron donating moieties (i.e., reducers), the quinones and polycondensed aromatic functional groups are the components accepting electrons (oxidants). The redox capacity of biochar depends on feedstock properties and pyrolysis conditions. This paper aims to review and summarize the various synthesis techniques for biochars and the methods for probing their redox characteristics. We review the abiotic and microbial applications of biochars as electron donors, electron acceptors, or electron shuttles for pollutant degradation, metal(loid)s (im)mobilization, nutrient transformation, and discuss the underlying mechanisms. Furthermore, knowledge gaps that exist in the exploration and differentiation of the electron transfer mechanisms involving biochars are also identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Dynamism in Electronic Performance Support Systems.

    ERIC Educational Resources Information Center

    Laffey, James

    1995-01-01

    Describes a model for dynamic electronic performance support systems based on NNAble, a system developed by the training group at Apple Computer. Principles for designing dynamic performance support are discussed, including a systems approach, performer-centered design, awareness of situated cognition, organizational memory, and technology use.…

  6. Designing Transferable Skills Inventory for Assessing Students Using Group Discussion: A Case Study of First Year Electrical and Electronics Engineering Students

    ERIC Educational Resources Information Center

    Tejaswani, K.; Madhuri, G. V.

    2015-01-01

    Employability skills among engineering graduates have been a concern due to their inability to perform on a professional platform to the employer's expected level. As they are higher cognitive skills, they are to be nurtured during the graduation period. Keeping this in view, group discussions are identified as one of the methods to elicit…

  7. Classroom Voting Questions to Stimulate Discussions in Precalculus

    ERIC Educational Resources Information Center

    Cline, Kelly; Zullo, Holly; Huckaby, David A.; Storm, Christopher; Stewart, Ann

    2018-01-01

    Classroom voting can be an effective way to stimulate student discussions. In this pedagogy, the instructor poses a multiple-choice question to the class, and then allows a few minutes for consideration and small-group discussion before students vote, either with clickers, cell phones, or a non-electronic method. After the vote the instructor…

  8. Electronic structure of antibiotic erythromycin

    NASA Astrophysics Data System (ADS)

    Novak, Igor; Kovač, Branka

    2015-03-01

    The electronic structure of erythromycin A (ERYMA) molecule has been studied by UV photoelectron spectroscopy and assigned (in the low ionization energy region only) by empirical arguments. The two orbitals with highest energy (lowest ionization energy) are localized on the nitrogen of the desosamine sugar functional group and on the ester group of macrolide (lactone) ring. We discuss how these orbital energies can help to rationalize the known mode of binding of ERYMA to their biological receptors.

  9. The Arithmetic of Aromaticity.

    ERIC Educational Resources Information Center

    Glidewell, Christopher; Lloyd, Douglas

    1986-01-01

    Explores the extent to which, in polycyclic hydrocarbons, the total pi electron population tends to form small (4n plus 2) groups and avoid the formation of 4n groups. Also discusses the relation of this trend to resonance energy stabilizations. (JN)

  10. Electron tunneling through covalent and noncovalent pathways in proteins

    NASA Technical Reports Server (NTRS)

    Beratan, David N.; Onuchic, Jose Nelson; Hopfield, J. J.

    1987-01-01

    A model is presented for electron tunneling in proteins which allows the donor-acceptor interaction to be mediated by the covalent bonds between amino acids and noncovalent contacts between amino acid chains. The important tunneling pathways are predicted to include mostly bonded groups with less favorable nonbonded interactions being important when the through bond pathway is prohibitively long. In some cases, vibrational motion of nonbonded groups along the tunneling pathway strongly influences the temperature dependence of the rate. Quantitative estimates for the sizes of these noncovalent interactions are made and their role in protein mediated electron transport is discussed.

  11. Electronic and Photoelectron Spectroscopy of Toluene

    NASA Astrophysics Data System (ADS)

    Gardner, Adrian M.; Green, Alistair M.; Tame-Reyes, Victor; Wright, Timothy G.

    2012-06-01

    Electronic and photoelectron spectra of toluene are presented and discussed. The utilization of a recently reported scheme for assigning the normal vibrations of substituted benzenes allows these spectra to be compared to those of other molecules with unprecedented clarity. Changes in vibrational activity within a series of substituted benzene molecules will be discussed, specifically the increased rate of intramolecular vibrational energy redistribution observed in molecules where the substituent is a methyl group. A. M. Gardner and T. G. Wright, J. Chem. Phys., 135, 114305 (2011)

  12. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study.

    PubMed

    Dostanić, J; Lončarević, D; Zlatar, M; Vlahović, F; Jovanović, D M

    2016-10-05

    A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31+G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σp constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO2 photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Electronic and magnetic properties of second main-group and second sub-group metals substitution for Al in delafossite CuAlO2

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Jun; Liu, Fu-Sheng; Liu, Zheng-Tang

    2015-07-01

    A systematic theoretical investigation has been carried out for the structural, electronic and magnetic properties of second main-group and second sub-group metals substitution for Al in delafossite CuAlO2 in the framework of density functional theory. The structural parameters and formation energies were calculated and discussed. The appearance of enhanced p-type conductivity after doping has been analyzed. Moreover, it is shown that all dopants have relatively large magnetic moments, but their ferromagnetic states are unstable, showing that their potential application in dilute magnetic semiconductors is not applicable.

  14. Electronic reserves: copyright and permissions

    PubMed Central

    Graves, Karen J.

    2000-01-01

    Electronic reserves present a new service option for libraries to provide needed materials during hours that the library is not open and to user groups located some distance from library collections. Possible changes to current copyright law and publishers permissions policies have delayed the development of electronic reserves in many libraries. This paper reviews the current state of electronic reserves materials in the publishing and library communities and presents the results of a survey of publishers to determine permissions policies for electronic materials. Issues of concern to both libraries and publishers are discussed. PMID:10658960

  15. 2-Aryl-2-nitroacetates as Central Precursors to Aryl Nitromethanes, α-Ketoesters, and α-Amino Acids

    PubMed Central

    Metz, Alison E.

    2013-01-01

    Nitroarylacetates are useful small molecular building blocks that act as precursors to α-ketoesters and aryl nitromethanes as well as α-amino acids. Methods were developed that produce each of these compound types in good yields. Two different conditions for decarboxylation are discussed for substrates with neutral and electron-poor aryl groups versus electron-rich aryl groups. For formation of the α-ketoesters, new mild conditions for the Nef disproportionation were identified. PMID:23245626

  16. Group-theoretical analysis of two-dimensional hexagonal materials

    NASA Astrophysics Data System (ADS)

    Minami, Susumu; Sugita, Itaru; Tomita, Ryosuke; Oshima, Hiroyuki; Saito, Mineo

    2017-10-01

    Two-dimensional hexagonal materials such as graphene and silicene have highly symmetric crystal structures and Dirac cones at the K point, which induce novel electronic properties. In this report, we calculate their electronic structures by using density functional theory and analyze their band structures on the basis of the group theory. Dirac cones frequently appear when the symmetry at the K point is high; thus, two-dimensional irreducible representations are included. We discuss the relationship between symmetry and the appearance of the Dirac cone.

  17. Electronic spectra of 2- and 3-tolunitrile in the gas phase. I. A study of methyl group internal rotation via rovibronically resolved spectroscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ruiz-Santoyo, José Arturo; Álvarez-Valtierra, Leonardo, E-mail: leoav@fisica.ugto.mx; Wilke, Josefin

    2016-01-28

    Rotationally resolved fluorescence excitation spectra of the origin bands in the S{sub 1}←S{sub 0} transition of 2-tolunitrile (2TN) and 3-tolunitrile (3TN) have been recorded in the collision-free environment of a molecular beam. Analyses of these data provide the rotational constants of each molecule and the potential energy curves governing the internal rotation of the attached methyl groups in both electronic states. 2TN exhibits much larger barriers along this coordinate than 3TN. Interestingly, the electronic transition dipole moment in both molecules is markedly influenced by the position of the attached methyl group rather than the position of the cyano group; possiblemore » reasons for this intriguing behavior are discussed.« less

  18. Instructional Utilization of the Internet in Public School Settings.

    ERIC Educational Resources Information Center

    Milheim, William D.

    1997-01-01

    Discussion of use of the Internet in educational settings focuses on providing specific information for elementary and secondary school personnel to increase their awareness and utilization of the Internet. Topics include accessing the Internet; school access; origins of the Internet; electronic mail; discussion groups, or listservs; newsgroups;…

  19. Client perceptions of the mental health engagement network: a qualitative analysis of an electronic personal health record.

    PubMed

    Forchuk, Cheryl; Reiss, Jeffrey P; O'Regan, Tony; Ethridge, Paige; Donelle, Lorie; Rudnick, Abraham

    2015-10-14

    Information technologies such as websites, mobile phone applications, and virtual reality programs have been shown to deliver innovative and effective treatments for mental illness. Much of the research studying electronic mental health interventions focuses on symptom reduction; however, to facilitate the implementation of electronic interventions in usual mental health care, it is also important to investigate the perceptions of clients who will be using the technologies. To this end, a qualitative analysis of focus group discussions regarding the Mental Health Engagement Network, a web-based personal health record and smartphone intervention, is presented here. Individuals living in the community with a mood or psychotic disorder (n = 394) were provided with a smartphone and access to an electronic personal health record, the Lawson SMART Record, for 12 to 18 months to manage their mental health. This study employed a delayed-implementation design and obtained both quantitative and qualitative data through individual interviews and focus group sessions. Participants had the opportunity to participate in voluntary focus group sessions at three points throughout the study to discuss their perceptions of the technologies. Qualitative data from 95 focus group participants were analysed using a thematic analysis. Four overarching themes emerged from focus group discussions: 1) Versatile functionality of the Lawson SMART Record and smartphone facilitated use; 2) Aspects of the technologies as barriers to use; 3) Use of the Mental health Engagement Network technologies resulted in perceived positive outcomes; 4) Future enhancement of the Lawson SMART Record and intervention is recommended. These qualitative data provide a valuable contribution to the understanding of how smarttechnologies can be integrated into usual mental health care. Smartphones are extremely portable andcommonplace in society. Therefore, clients can use these devices to manage and track mental health issuesin any place at almost any time without feeling stigmatized. Assessing clients' perspectives regarding the use of smart technologies in mental health care provides an invaluable addition to the current literature. Qualitative findings support the feasibility of implementing a smartphone and electronic personal health record intervention with individuals who are living in the community and experiencing a mental illness, and provide considerations for future development and implementation.

  20. Current status and future directions for in situ transmission electron microscopy

    PubMed Central

    Taheri, Mitra L.; Stach, Eric A.; Arslan, Ilke; Crozier, P.A.; Kabius, Bernd C.; LaGrange, Thomas; Minor, Andrew M.; Takeda, Seiji; Tanase, Mihaela; Wagner, Jakob B.; Sharma, Renu

    2016-01-01

    This review article discusses the current and future possibilities for the application of in situ transmission electron microscopy to reveal synthesis pathways and functional mechanisms in complex and nanoscale materials. The findings of a group of scientists, representing academia, government labs and private sector entities (predominantly commercial vendors) during a workshop, held at the Center for Nanoscale Science and Technology- National Institute of Science and Technology (CNST-NIST), are discussed. We provide a comprehensive review of the scientific needs and future instrument and technique developments required to meet them. PMID:27566048

  1. Distributions of methyl group rotational barriers in polycrystalline organic solids

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Beckmann, Peter A., E-mail: pbeckman@brynmawr.edu, E-mail: wangxianlong@uestc.edu.cn; Conn, Kathleen G.; Division of Education and Human Services, Neumann University, One Neumann Drive, Aston, Pennsylvania 19014-1298

    We bring together solid state {sup 1}H spin-lattice relaxation rate measurements, scanning electron microscopy, single crystal X-ray diffraction, and electronic structure calculations for two methyl substituted organic compounds to investigate methyl group (CH{sub 3}) rotational dynamics in the solid state. Methyl group rotational barrier heights are computed using electronic structure calculations, both in isolated molecules and in molecular clusters mimicking a perfect single crystal environment. The calculations are performed on suitable clusters built from the X-ray diffraction studies. These calculations allow for an estimate of the intramolecular and the intermolecular contributions to the barrier heights. The {sup 1}H relaxation measurements,more » on the other hand, are performed with polycrystalline samples which have been investigated with scanning electron microscopy. The {sup 1}H relaxation measurements are best fitted with a distribution of activation energies for methyl group rotation and we propose, based on the scanning electron microscopy images, that this distribution arises from molecules near crystallite surfaces or near other crystal imperfections (vacancies, dislocations, etc.). An activation energy characterizing this distribution is compared with a barrier height determined from the electronic structure calculations and a consistent model for methyl group rotation is developed. The compounds are 1,6-dimethylphenanthrene and 1,8-dimethylphenanthrene and the methyl group barriers being discussed and compared are in the 2–12 kJ mol{sup −1} range.« less

  2. Computer simulation of electron flow in linear-beam microwave tubes

    NASA Astrophysics Data System (ADS)

    Kumar, Lalit

    1990-12-01

    The computer simulation of electron flow in linear-beam microwave tubes, such as a travelling-wave tube (TWT) and klystron, is used for designing and optimising the electron gun and collector and for analysing the large-signal beam-wave interaction phenomenon. Major aspects of simulation of electron flow in static and rf fields present in such tubes are discussed. Some advancements made in this respect and results obtained from computer programs developed by the research group at CEERI for a gridded electron gun, depressed collector, and large-signal analysis of TWT and klystron are presented.

  3. Space Station Workshop: Commercial Missions and User Requirements

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The topics of discussion addressed during a three day workshop on commercial application in space are presented. Approximately half of the program was directed towards an overview and orientation to the Space Station Project; the technical attributes of space; and present and future potential commercial opportunities. The remaining time was spent addressing technological issues presented by previously-formed industry working groups, who attempted to identify the technology needs, problems or issues faced and/or anticipated by the following industries: extraction (mining, agriculture, petroleum, fishing, etc.); fabrication (manufacturing, automotive, aircraft, chemical, pharmaceutical and electronics); and services (communications, transportation and retail robotics). After the industry groups presented their technology issues, the workshop divided into smaller discussion groups composed of: space experts from NASA; academia; industry experts in the appropriate disciplines; and other workshop participants. The needs identified by the industry working groups, space station technical requirements, proposed commercial ventures and other issues related to space commercialization were discussed. The material summarized and reported are the consensus from the discussion groups.

  4. Transmission effects in unfolding electronic-vibrational electron-molecule energy-loss spectra

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang Shiyang; Khakoo, Murtadha A.; Johnson, Paul V.

    2006-03-15

    The results of an investigation concerning the sensitivity of conventional unfolding methods applied to electronic-vibrational electron-energy-loss spectra to the transmission efficiency of electron spectrometers are presented. This investigation was made in an effort to understand differences in the differential cross sections for excitation of low-lying electronic states determined experimentally by various groups using electronic-vibrational energy-loss spectra of N{sub 2}. In these experiments, very similar spectral unfolding methods were used, which relied on similar Franck-Condon factors. However, the overall analyses of the electron scattering spectra (by the individual groups) resulted in large differences among the differential cross sections determined from thesemore » energy-loss spectra. The transmission response of the experimental apparatus to different-energy scattered electrons has often been discussed as a key factor that caused these disagreements. The present investigation shows in contrast that the effect of transmission is smaller than that required to independently explain such differences, implying that other systematic effects are responsible for the existing differences between measurements.« less

  5. Space Technology Plasma Issues in 2001

    NASA Technical Reports Server (NTRS)

    Garrett, Henry (Editor); Feynman, Joan (Editor); Gabriel, Stephen (Editor)

    1986-01-01

    The purpose of the workshop was to identify and discuss plasma issues that need to be resolved during the next 10 to 20 years (circa 2001) to facilitate the development of the advanced space technology that will be required 20 or 30 years into the future. The workshop consisted of 2 days of invited papers and 2 sessions of contributed poster papers. During the third day the meeting broke into 5 working groups, each of which held discussions and then reported back to the conference as a whole. The five panels were: Measurements Technology and Active Experiments Working Group; Advanced High-Voltage, High-Power and Energy-Storage Space Systems Working Group; Large Structures and Tethers Working Group; Plasma Interactions and Surface/Materials Effects Working Group; and Beam Plasmas, Electronic Propulsion and Active Experiments Using Beams Working Group.

  6. The Use of Electronic Voting Systems in Lectures within Business and Marketing: A Case Study of Their Impact on Student Learning

    ERIC Educational Resources Information Center

    Masikunas, George; Panayiotidis, Andreas; Burke, Linda

    2007-01-01

    This article presents a case study of the impact on student learning of introducing an electronic voting system (EVS) into large-group lectures for first-year undergraduate students undertaking degrees in marketing and business systems. We discuss the potential for using EVS-style interactive lectures in marketing and business programmes. We then…

  7. Netiquettes for Networkers.

    ERIC Educational Resources Information Center

    McMurdo, George

    1995-01-01

    Presents 20 networking etiquette guidelines taken from electronic and print sources. Highlights include focusing on one subject, condensing messages, editing quotes, spelling and grammar, typography, mistakes, acronyms, humor, researching discussion groups, intellectual property and copyright, manners, ethics, and damage. (AEF)

  8. Young adults' favorable perceptions of snus, dissolvable tobacco products, and electronic cigarettes: findings from a focus group study.

    PubMed

    Choi, Kelvin; Fabian, Lindsey; Mottey, Neli; Corbett, Amanda; Forster, Jean

    2012-11-01

    We explored young adults' perceptions of snus (spitless moist snuff packed in porous bags), dissolvable tobacco products, and electronic cigarettes and intention to try these products. We conducted 11 focus group discussions involving a total of 66 young adults (18-26 years old) on these new tobacco products (e.g., harmfulness, potential as quit aids, intention to try) held between July and December 2010. We analyzed discussions using a thematic approach. Participants generally reported positive perceptions of the new products, particularly because they came in flavors. Few negative perceptions were reported. Although some participants believed these products were less harmful than cigarettes and helpful in quitting smoking, others thought the opposite, particularly regarding electronic cigarettes. Participants also commented that these products could be gateways to cigarette smoking. Half of the participants, including a mix of smokers and nonsmokers, admitted they would try these products if offered by a friend. Young adults perceive the new tobacco products positively and are willing to experiment with them. Eliminating flavors in these products may reduce young adults' intentions to try these products.

  9. Conversational Scholarship in Cyberspace: The Evolution and Activities of H-Net, the Online Network for the Humanities.

    ERIC Educational Resources Information Center

    Turnbull, Paul

    1996-01-01

    The origins and current use of H-Net, an online humanities network on the World Wide Web, are examined. H-Net currently sponsors 73 electronic discussion lists that reach subscribers in 68 countries. Discussion groups have not met expectations for scholarly exchange, possibly because of plagiarism and copyright concerns. New ventures include book…

  10. A Funny Thing Happened on the Way to the Forum: Electronic Discussion and Foreign Language Learning.

    ERIC Educational Resources Information Center

    Hanna, Barbara; de Nooy, Juliana

    2003-01-01

    Examines participation of language students in on-line discussion groups with native speakers of the target language. Examines the threads started by four anglophone students of French when they post messages to a forum on the Web site of the French newspaper "Le Monde." Investigation of these examples points to the ways in which electronic…

  11. Use of a Wiki-Based Software to Manage Research Group Activities

    ERIC Educational Resources Information Center

    Wang, Ting; Vezenov, Dmitri V.; Simboli, Brian

    2014-01-01

    This paper discusses use of the wiki software Confluence to organize research group activities and lab resources. Confluence can serve as an electronic lab notebook (ELN), as well as an information management and collaboration tool. The article provides a case study in how researchers can use wiki software in "home-grown" fashion to…

  12. Analysis of thermoelectric properties of high-temperature complex alloys of nickel-base, iron-base and cobalt-base groups

    NASA Technical Reports Server (NTRS)

    Holanda, R.

    1984-01-01

    The thermoelectric properties alloys of the nickel-base, iron-base, and cobalt-base groups containing from 1% to 25% 106 chromium were compared and correlated with the following material characteristics: atomic percent of the principle alloy constituent; ratio of concentration of two constituents; alloy physical property (electrical resistivity); alloy phase structure (percent precipitate or percent hardener content); alloy electronic structure (electron concentration). For solid-solution-type alloys the most consistent correlation was obtained with electron concentration, for precipitation-hardenable alloys of the nickel-base superalloy group, the thermoelectric potential correlated with hardener content in the alloy structure. For solid-solution-type alloys, no problems were found with thermoelectric stability to 1000; for precipitation-hardenable alloys, thermoelectric stability was dependent on phase stability. The effects of the compositional range of alloy constituents on temperature measurement uncertainty are discussed.

  13. An Internet discussion board for parents of mentally ill young children.

    PubMed

    Scharer, Kathleen

    2005-01-01

    This paper reports parents' use of electronic bulletin board for social support during a pilot study of an Internet intervention. Parents participated for a mean of 13.83 weeks. The convenience sample consisted of six parents. Data were from site access information and parents' postings. Excluding one mother who checked frequently for messages, mothers have an average of 5.2 postings. Excluding this one mother, the postings/ accesses ratio was greater than 60%. Parents made postings in four categories of "child's illness" having 37 comments and 36 comments for "group maintenance". While the study findings cannot be generalized, these results suggest that parents will use electronic discussion boards.

  14. Theoretical Studies of Gas Phase Elementary and Carbon Nanostructure Growth Reactions

    DTIC Science & Technology

    2013-09-19

    time dynamics of electron transfer in a prototype redox reaction that occurs in reactive collisions between neutral and ionic fullerenes is discussed...The LvNMD show that the electron transfer occurs within 60 fs directly preceding the collision of the fullerenes , followed by structural changes...collisions between neutral and multiply charged fullerenes . 2 B. Collaboration with the AFRL. Collaboration with the VIggiano group at AFRL at

  15. STRUCTURAL DIVERSITY IN SOLID STATE CHEMISTRY:A Story of Squares and Triangles

    NASA Astrophysics Data System (ADS)

    Lee, Stephen

    1996-10-01

    A simple method for calculating the electronic energy of extended solids is discussed in this review. This method is based on the Huckel or tight-binding theory in which an explicit pairwise repulsion is added to the generally attractive forces of the partially filled valence electron bands. An expansion based on the power moments of the electronic density of states is discussed, and the structural energy difference theorem is reviewed. The repulsive energy is found to vary linearly with the second power moment of the electronic density of states. These results are then used to show why there is such a diversity of structure in the solid state. The elemental structures of the main group are rationalized by the above methods. It is the third and fourth power moments (which correspond in part to triangles and squares of bonded atoms) that account for much of the elemental structures of the main group elements of the periodic table. This serves as an introduction to further rationalizations of transition for noble metal alloy, binary and ternary telluride and selenide, and other intermetallic structures.Thus a cohesive picture of both covalent and metallic bonding is presented in this review, illustrating the importance of atomic orbitals and their overlap integrals.

  16. Improving temperature monitoring in the vaccine cold chain at the periphery: an intervention study using a 30-day electronic refrigerator temperature logger (Fridge-tag).

    PubMed

    Kartoğlu, Umit; Nelaj, Erida; Maire, Denis

    2010-05-28

    This intervention study was conducted in Albania to establish the superiority of the Fridge-tag (30-day electronic refrigerator temperature logger) against thermometers. Intervention sites used Fridge-tag and a modified temperature control record sheet, while control sites continued with their routine operation with thermometers. All refrigerators in both groups were equipped with downloadable electronic data loggers to record temperatures for reference. Focus group sessions were conducted with involved staff to discuss temperature monitoring, Fridge-tag use and its user-friendliness. Significant discrepancies were observed between thermometer readings and the electronic data loggers in control sites, while all alarms from Fridge-tag were confirmed in the intervention group. Thermometers are not sufficient to monitor temperatures in refrigerators since they miss the great majority of low and high alarms. Fridge-tag has proven to be an effective tool in providing health workers with the information they need to take the necessary actions when there are refrigerator temperature variations. (c) 2010 Elsevier Ltd. All rights reserved.

  17. Electronic imaging of the human body

    NASA Astrophysics Data System (ADS)

    Vannier, Michael W.; Yates, Randall E.; Whitestone, Jennifer J.

    1992-09-01

    The Human Engineering Division of the Armstrong Laboratory (USAF); the Mallinckrodt Institute of Radiology; the Washington University School of Medicine; and the Lister-Hill National Center for Biomedical Communication, National Library of Medicine are sponsoring a working group on electronic imaging of the human body. Electronic imaging of the surface of the human body has been pursued and developed by a number of disciplines including radiology, forensics, surgery, engineering, medical education, and anthropometry. The applications range from reconstructive surgery to computer-aided design (CAD) of protective equipment. Although these areas appear unrelated, they have a great deal of commonality. All the organizations working in this area are faced with the challenges of collecting, reducing, and formatting the data in an efficient and standard manner; storing this data in a computerized database to make it readily accessible; and developing software applications that can visualize, manipulate, and analyze the data. This working group is being established to encourage effective use of the resources of all the various groups and disciplines involved in electronic imaging of the human body surface by providing a forum for discussing progress and challenges with these types of data.

  18. Computer Networks and Networking: A Primer.

    ERIC Educational Resources Information Center

    Collins, Mauri P.

    1993-01-01

    Provides a basic introduction to computer networks and networking terminology. Topics addressed include modems; the Internet; TCP/IP (Transmission Control Protocol/Internet Protocol); transmission lines; Internet Protocol numbers; network traffic; Fidonet; file transfer protocol (FTP); TELNET; electronic mail; discussion groups; LISTSERV; USENET;…

  19. Electronic patient record use during ward rounds: a qualitative study of interaction between medical staff.

    PubMed

    Morrison, Cecily; Jones, Matthew; Blackwell, Alan; Vuylsteke, Alain

    2008-01-01

    Electronic patient records are becoming more common in critical care. As their design and implementation are optimized for single users rather than for groups, we aimed to understand the differences in interaction between members of a multidisciplinary team during ward rounds using an electronic, as opposed to paper, patient medical record. A qualitative study of morning ward rounds of an intensive care unit that triangulates data from video-based interaction analysis, observation, and interviews. Our analysis demonstrates several difficulties the ward round team faced when interacting with each other using the electronic record compared with the paper one. The physical setup of the technology may impede the consultant's ability to lead the ward round and may prevent other clinical staff from contributing to discussions. We discuss technical and social solutions for minimizing the impact of introducing an electronic patient record, emphasizing the need to balance both. We note that awareness of the effects of technology can enable ward-round teams to adapt their formations and information sources to facilitate multidisciplinary communication during the ward round.

  20. Electronic patient record use during ward rounds: a qualitative study of interaction between medical staff

    PubMed Central

    Morrison, Cecily; Jones, Matthew; Blackwell, Alan; Vuylsteke, Alain

    2008-01-01

    Introduction Electronic patient records are becoming more common in critical care. As their design and implementation are optimized for single users rather than for groups, we aimed to understand the differences in interaction between members of a multidisciplinary team during ward rounds using an electronic, as opposed to paper, patient medical record. Methods A qualitative study of morning ward rounds of an intensive care unit that triangulates data from video-based interaction analysis, observation, and interviews. Results Our analysis demonstrates several difficulties the ward round team faced when interacting with each other using the electronic record compared with the paper one. The physical setup of the technology may impede the consultant's ability to lead the ward round and may prevent other clinical staff from contributing to discussions. Conclusions We discuss technical and social solutions for minimizing the impact of introducing an electronic patient record, emphasizing the need to balance both. We note that awareness of the effects of technology can enable ward-round teams to adapt their formations and information sources to facilitate multidisciplinary communication during the ward round. PMID:19025662

  1. Supersonic plasma beams with controlled speed generated by the alternative low power hybrid ion engine (ALPHIE) for space propulsion

    NASA Astrophysics Data System (ADS)

    Conde, L.; Domenech-Garret, J. L.; Donoso, J. M.; Damba, J.; Tierno, S. P.; Alamillo-Gamboa, E.; Castillo, M. A.

    2017-12-01

    The characteristics of supersonic ion beams from the alternative low power hybrid ion engine (ALPHIE) are discussed. This simple concept of a DC powered plasma accelerator that only needs one electron source for both neutral gas ionization and ion beam neutralization is also examined. The plasma production and space charge neutralization processes are thus coupled in this plasma thruster that has a total DC power consumption of below 450 W, and uses xenon or argon gas as a propellant. The operation parameters of the plasma engine are studied in the laboratory in connection with the ion energy distribution function obtained with a retarding-field energy analyzer. The ALPHIE plasma beam expansion produces a mesothermal plasma flow with two-peaked ion energy distribution functions composed of low and high speed ion groups. The characteristic drift velocities of the fast ion groups, in the range 36.6-43.5 Km/s, are controlled by the acceleration voltage. These supersonic speeds are higher than the typical ion sound velocities of the low energy ion group produced by the expansion of the plasma jet. The temperatures of the slow ion population lead to ion Debye lengths longer than the electron Debye lengths. Furthermore, the electron impact ionization can coexist with collisional ionization by fast ions downstream the grids. Finally, the performance characteristics and comparisons with other plasma accelerator schemes are also discussed.

  2. Young Adults’ Favorable Perceptions of Snus, Dissolvable Tobacco Products, and Electronic Cigarettes: Findings From a Focus Group Study

    PubMed Central

    Fabian, Lindsey; Mottey, Neli; Corbett, Amanda; Forster, Jean

    2012-01-01

    Objectives. We explored young adults’ perceptions of snus (spitless moist snuff packed in porous bags), dissolvable tobacco products, and electronic cigarettes and intention to try these products. Methods. We conducted 11 focus group discussions involving a total of 66 young adults (18–26 years old) on these new tobacco products (e.g., harmfulness, potential as quit aids, intention to try) held between July and December 2010. We analyzed discussions using a thematic approach. Results. Participants generally reported positive perceptions of the new products, particularly because they came in flavors. Few negative perceptions were reported. Although some participants believed these products were less harmful than cigarettes and helpful in quitting smoking, others thought the opposite, particularly regarding electronic cigarettes. Participants also commented that these products could be gateways to cigarette smoking. Half of the participants, including a mix of smokers and nonsmokers, admitted they would try these products if offered by a friend. Conclusions. Young adults perceive the new tobacco products positively and are willing to experiment with them. Eliminating flavors in these products may reduce young adults’ intentions to try these products. PMID:22813086

  3. Internet Connections to Mathematics Education.

    ERIC Educational Resources Information Center

    Day, Roger

    1995-01-01

    Presents Internet connections appropriate for mathematics education; provides descriptions of ways that mathematics educators can access electronic resources such as e-mail, discussion groups, gopher servers, and transfer of files; and provides hints and examples from classroom connections and professional applications. (18 references) (Author/MKR)

  4. Proceedings of the November 2011 Traceability Research Summit: this report is the third in a series on Traceability Summits sponsored by IFT beginning in July 2011.

    PubMed

    Hickey, Caitlin; Bhatt, Tejas

    2013-12-01

    Fifty thought leaders in the area of food traceability met for a 3rd time to discuss methodologies and finalize the principles that define their vision for traceability. Participants in the summit included representatives from industry, trade associations, government, academia, consumer groups, and more. One main focus of this summit included a discussion on the current regulations and voluntary initiatives in place regarding traceability. Overall, it was recognized that the recommendations from this summit group would be more specific and stringent in comparison to these current regulations and initiatives. The participants sought to be leaders in the traceability arena, with their recommendations leading the industry to optimal traceability systems and methods. Participants agreed on many principles for their vision of traceability, emphasizing the importance of access to traceability data. They discussed having industry be asked for "basic" tracing data prior to the need for a large-scale investigation, having standards for sharing data, and having the data in electronic form. Participants foresaw the importance of capturing data electronically in the future, although they recognized that many firms do not currently do this. The group also saw a need for a transition period to implement changes, and to provide implementation training and resource aid to small businesses. Summit participants discussed specific definitions and examples for key data elements and critical tracking events that could be used by industry to capture tracing data at specific points within the supply chain. Overall, participants refined the goals of the summit group and started to identify specific ways to achieve those goals. © 2013 Institute of Food Technologists®

  5. Magnetic holes in the dipolarized magnetotail: ion and electron anisotropies

    NASA Astrophysics Data System (ADS)

    Shustov, P.; Artemyev, A.; Zhang, X. J.; Yushkov, E.; Petrukovich, A. A.

    2017-12-01

    We conduct statistics on magnetic holes observed by THEMIS spacecraft in the near-Earth magnetotail. Groups of holes are detected after dipolarizations in the quiet, equatorial plasma sheet. Magnetic holes are characterized by significant magnetic field depressions (up to 50%) and strong electron currents ( 10-50 nA/m2), with spatial scales much smaller than the ion gyroradius. These magnetic holes are populated by hot (>10 keV), transversely anisotropic electrons supporting the pressure balance. We present statistical properties of these sub-ion scale magnetic holes and discuss possible mechanisms on the hole formation.

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

    NASA Astrophysics Data System (ADS)

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

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

  7. Australian Academic Use of the Internet.

    ERIC Educational Resources Information Center

    Applebee, Andrelyn C.; Clayton, Peter; Pascoe, Celina

    1997-01-01

    A study of academic staff at the University of Canberra (Australia) in 1995 determined use of electronic mail, Telnet, file transfer protocol (FTP) software, World Wide Web, library and document delivery services, discussion groups, and student communication. Examined demographic characteristics of faculty (discipline, employment status, gender,…

  8. Electronic Support Groups: An Open Line of Communication in Contested Illness

    PubMed Central

    Murphy, Michael; Kontos, Nicholas; Freudenreich, Oliver

    2017-01-01

    Background Patients with functional somatic syndromes are often difficult to treat. The relationship between doctors and patients can be strained, which limits communication. Instead, patients often communicate with each other over the Internet in electronic support groups. Objective This perspective summarizes studies of patient-to-patient communication over the Internet and uses the concept of contested illness to provide insights into the experiences of patients with functional somatic disorders. Discussion Conflict between a patient and their physician is a key feature of functional somatic syndromes. Physicians and patients do not have a shared understanding or appreciation of the patient’s experiences. Patients with functional somatic syndromes often value their own embodied experience over medical knowledge. At the same time, they remain deeply invested in finding a “good doctor” who believes that the patient is suffering, agrees with their conception of the cause, and assents to the treatment as directed by the patient. Electronic support groups reinforce these beliefs. Conclusion Patients may benefit from a compromising, collaborative approach that is realistic about the limitations of medical knowledge. However, physicians should not engage in unsafe treatment practices. Electronic support groups exist for a wide range of illnesses and the issues that rise to the surface in functional somatic syndromes likely occur to some extent with almost every patient. PMID:27421707

  9. Perspectives of healthcare practitioners: An exploration of interprofessional communication using electronic medical records.

    PubMed

    Bardach, Shoshana H; Real, Kevin; Bardach, David R

    2017-05-01

    Contemporary state-of-the-art healthcare facilities are incorporating technology into their building design to improve communication and patient care. However, technological innovations may also have unintended consequences. This study seeks to better understand how technology influences interprofessional communication within a hospital setting based in the United States. Nine focus groups were conducted including a range of healthcare professions. The focus groups explored practitioners' experiences working on two floors of a newly designed hospital and included questions about the ways in which technology shaped communication with other healthcare professionals. All focus groups were recorded, transcribed, and coded to identify themes. Participant responses focused on the electronic medical record, and while some benefits of the electronic medical record were discussed, participants indicated use of the electronic medical record has resulted in a reduction of in-person communication. Different charting approaches resulted in barriers to communication between specialties and reduced confidence that other practitioners had received one's notes. Limitations in technology-including limited computer availability, documentation complexity, and sluggish sign-in processes-also were identified as barriers to effective and timely communication between practitioners. Given the ways in which technology shapes interprofessional communication, future research should explore how to create standardised electronic medical record use across professions at the optimal level to support communication and patient care.

  10. e-Consultation Improves Efficacy in Thoracic Surgery Outpatient Clinics.

    PubMed

    Novoa, Nuria M; Gómez, Maria Teresa; Rodríguez, María; Jiménez López, Marcelo F; Aranda, Jose L; Bollo de Miguel, Elena; Diez, Florentino; Hernández Hernández, Jesús; Varela, Gonzalo

    2016-11-01

    The aim of this study is analysing the impact of the systematic versus occasional videoconferencing discussion of patients with two respiratory referral units along 6 years of time over the efficiency of the in-person outpatient clinics of a thoracic surgery service. Retrospective and comparative study of the evaluated patients through videoconferencing and in-person first visits during two equivalents periods of time: Group A (occasional discussion of cases) between 2008-2010 and Group B (weekly regular discussion) 2011-2013. Data were obtained from two prospective and electronic data bases. The number of cases discussed using e-consultation, in-person outpatient clinics evaluation and finally operated on under general anaesthesia in each period of time are presented. For efficiency criteria, the index: number of operated on cases/number of first visit outpatient clinic patients is created. Non-parametric Wilcoxon test is used for comparison. The mean number of patients evaluated at the outpatient clinics/year on group A was 563 versus 464 on group B. The median number of cases discussed using videoconferencing/year was 42 for group A versus 136 for group B. The mean number of operated cases/first visit at the outpatient clinics was 0.7 versus 0.87 in group B (P=.04). The systematic regular discussion of cases using videoconferencing has a positive impact on the efficacy of the outpatient clinics of a Thoracic Surgery Service measured in terms of operated cases/first outpatient clinics visit. Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Tunable delay time and Hartman effect in graphene magnetic barriers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ban, Yue; Wang, Lin-Jun; Chen, Xi, E-mail: xchen@shu.edu.cn

    2015-04-28

    Tunable group delay and Hartman effect have been investigated for massless Dirac electrons in graphene magnetic barriers. In the presence of magnetic field, dwell time is found to be equal to net group delay plus the group delay contributing from the lateral shifts. The group delay times are discussed in both cases of normal and oblique incidence, to clarify the nature of Hartman effect. In addition, the group delay in transmission can be modulated from subluminality to superluminality by adjusting the magnetic field, which may also lead to potential applications in graphene-based microelectronics.

  12. Delay time and Hartman effect in strain engineered graphene

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong; Ban, Yue, E-mail: yban@shu.edu.cn

    2014-05-07

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect.

  13. Teaching Techniques and Course Content for International Finance.

    ERIC Educational Resources Information Center

    Esemuede, Samuel I.

    Noting the rapid and large changes in international finance over the past 2 decades, this paper offers suggestions for teaching business education courses on international finance. The paper recommends a combination of computer-assisted instruction and electronic classroom, discussion group, independent study, and lecture. Computer-assisted…

  14. Computer Conferencing and Electronic Mail.

    ERIC Educational Resources Information Center

    Kaye, Tony

    This paper discusses a number of problems associated with distance education methods used in adult education and training fields, including limited opportunities for dialogue and group interaction among students and between students and tutors; the expense of updating and modifying mass-produced print and audiovisual materials; and the relative…

  15. "Best Practices" and Collaborative Software in Online Teaching

    ERIC Educational Resources Information Center

    Tremblay, Remi

    2006-01-01

    In recent years, many distance educators and institutions have successfully adopted asynchronous text-based environments as the backbone of their online classrooms. Group email, electronic references, and course websites, coupled with online discussions, typically constitute the model of online course delivery. Although the structure and pacing of…

  16. Axoglial contacts in the area postrema of the cat - An ultrastructural study

    NASA Technical Reports Server (NTRS)

    Damelio, Fernando E.; Gibbs, Michael A.; Mehler, William R.; Philpott, Delbert E.; Savage, Wayne

    1986-01-01

    Axoglial contacts were observed in an ultrastructural study of the area postrema of the cat. According to the disposition of the electron-dense projections attached to the adjoining membranes these contacts were classified as symmetrical or asymmetrical. The axon profiles contained aggregations of clear vesicles randomly distributed or grouped in clusters adjacent to the electron-dense projections. Dense core vesicles were occasionally seen. The neuroglial profiles were either astrocytic or ependymoglial in nature. The astrocytes showed a clear cytoplasm, polymorphous vesicles, mitochondria, glycogen granules, and bundles of filaments. The ependymal cells, in contrast, had a more electron-dense and granular appearance, tubular structures, irregular vesicular formations, profiles of smooth reticuloendoplasm, and filaments grouped in bundles or isolated in the cytoplasm. The possibility that these contacts might play a role in the chemical transfer from neurons to glial cells is discussed on the basis of existing biochemical data.

  17. Electron microscopic changes of detrusor in benign enlargement of prostate and its clinical correlation.

    PubMed

    Yadav, Sher Singh; Bhattar, Rohit; Sharma, Lokesh; Banga, Gautam; Sadasukhi, Trilok Chandra

    2017-01-01

    To study the ultra structural changes in bladder musculature in cases of BPE and their clinical relevance. In this descriptive longitudinal, controlled, observational study patients were enrolled into three groups, group 1, group 2A and group 2B. Control group (group-1) consisted of age matched normal male patients, who underwent surveillance or diagnostic cystoscopy for microscopic hematuria or irritative symptoms. Case group (group-2) comprised of patients with BPE, undergoing TURP. Case group (group-2) was further classified into: Category 2A (patients not on catheter) and cat-egory 2B (patients on catheter). All relevant clinical parameters like IPSS, prostate size, Qmax, PVR were recorded. Cystoscopy and bladder biopsy were performed in all patients. Various ultrastructural parameters like myocytes, fascicular pattern, interstitial tissue, nerve hypertrophy and cell junction pattern were analyzed under electron microscope and they were clinically correlated using appropriate statistical tests. Control group had significant difference as compared to case group in terms of baseline parameters like IPSS, flow rate and prostate size, both preoperatively and postoperatively, except for PVR, which was seen only preoperatively. There was statistically significant difference in ultrastructural patterns between case and control group in all five electron microscopic patterns. However, no significant difference was found between the subcategories of case groups. BPE is responsible for ultra structural changes in detrusor muscle and these changes remain persistent even after TURP. Nerve hypertrophy, which was not thoroughly discussed in previous studies, is also one of the salient feature of this study. Copyright® by the International Brazilian Journal of Urology.

  18. Kinetic and Mechanistic Examination of Acid–Base Bifunctional Aminosilica Catalysts in Aldol and Nitroaldol Condensations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Collier, Virginia E.; Ellebracht, Nathan C.; Lindy, George I.

    The kinetic and mechanistic understanding of cooperatively catalyzed aldol and nitroaldol condensations is probed using a series of mesoporous silicas functionalized with aminosilanes to provide bifunctional acid–base character. Mechanistically, a Hammett analysis is performed to determine the effects of electron-donating and electron-withdrawing groups of para-substituted benzaldehyde derivatives on the catalytic activity of each condensation reaction. This information is also used to discuss the validity of previously proposed catalytic mechanisms and to propose a revised mechanism with plausible reaction intermediates. For both reactions, electron-withdrawing groups increase the observed rates of reaction, though resonance effects play an important, yet subtle, role inmore » the nitroaldol condensation, in which a p-methoxy electron-donating group is also able to stabilize the proposed carbocation intermediate. Additionally, activation energies and pre-exponential factors are calculated via the Arrhenius analysis of two catalysts with similar amine loadings: one catalyst had silanols available for cooperative interactions (acid–base catalysis), while the other was treated with a silanol-capping reagent to prevent such cooperativity (base-only catalysis). The values obtained for activation energies and pre-exponential factors in each reaction are discussed in the context of the proposed mechanisms and the importance of cooperative interactions in each reaction. The catalytic activity decreases for all reactions when the silanols are capped with trimethylsilyl groups, and higher temperatures are required to make accurate rate measurements, emphasizing the vital role the weakly acidic silanols play in the catalytic cycles. The results indicate that loss of acid sites is more detrimental to the catalytic activity of the aldol condensation than the nitroaldol condensation, as evidenced by the significant decrease in the pre-exponential factor for the aldol condensation when silanols are unavailable for cooperative interactions. Cooperative catalysis is evidenced by significant changes in the pre-exponential factor, rather than the activation energy for the aldol condensation.« less

  19. Kinetic and Mechanistic Examination of Acid–Base Bifunctional Aminosilica Catalysts in Aldol and Nitroaldol Condensations

    DOE PAGES

    Collier, Virginia E.; Ellebracht, Nathan C.; Lindy, George I.; ...

    2015-12-09

    The kinetic and mechanistic understanding of cooperatively catalyzed aldol and nitroaldol condensations is probed using a series of mesoporous silicas functionalized with aminosilanes to provide bifunctional acid–base character. Mechanistically, a Hammett analysis is performed to determine the effects of electron-donating and electron-withdrawing groups of para-substituted benzaldehyde derivatives on the catalytic activity of each condensation reaction. This information is also used to discuss the validity of previously proposed catalytic mechanisms and to propose a revised mechanism with plausible reaction intermediates. For both reactions, electron-withdrawing groups increase the observed rates of reaction, though resonance effects play an important, yet subtle, role inmore » the nitroaldol condensation, in which a p-methoxy electron-donating group is also able to stabilize the proposed carbocation intermediate. Additionally, activation energies and pre-exponential factors are calculated via the Arrhenius analysis of two catalysts with similar amine loadings: one catalyst had silanols available for cooperative interactions (acid–base catalysis), while the other was treated with a silanol-capping reagent to prevent such cooperativity (base-only catalysis). The values obtained for activation energies and pre-exponential factors in each reaction are discussed in the context of the proposed mechanisms and the importance of cooperative interactions in each reaction. The catalytic activity decreases for all reactions when the silanols are capped with trimethylsilyl groups, and higher temperatures are required to make accurate rate measurements, emphasizing the vital role the weakly acidic silanols play in the catalytic cycles. The results indicate that loss of acid sites is more detrimental to the catalytic activity of the aldol condensation than the nitroaldol condensation, as evidenced by the significant decrease in the pre-exponential factor for the aldol condensation when silanols are unavailable for cooperative interactions. Cooperative catalysis is evidenced by significant changes in the pre-exponential factor, rather than the activation energy for the aldol condensation.« less

  20. The Future of Scholarly Publishing

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2009

    2009-01-01

    In these times of financial crisis, much of the discussion about scholarly publishing has focused on budgets, the switch to electronic formats, and the future of the monograph. Throughout, however, university presses have continued to bring out important scholarship that is the mainstay of academe. "The Chronicle Review" asked a group of editors…

  1. Chemically derived graphene oxide: towards large-area thin-film electronics and optoelectronics.

    PubMed

    Eda, Goki; Chhowalla, Manish

    2010-06-11

    Chemically derived graphene oxide (GO) possesses a unique set of properties arising from oxygen functional groups that are introduced during chemical exfoliation of graphite. Large-area thin-film deposition of GO, enabled by its solubility in a variety of solvents, offers a route towards GO-based thin-film electronics and optoelectronics. The electrical and optical properties of GO are strongly dependent on its chemical and atomic structure and are tunable over a wide range via chemical engineering. In this Review, the fundamental structure and properties of GO-based thin films are discussed in relation to their potential applications in electronics and optoelectronics.

  2. Employing NMR Spectroscopy To Evaluate Transmission of Electronic Effects in 4-Substituted Chalcones

    NASA Astrophysics Data System (ADS)

    Wachter-Jurcsak, Nanette; Zamani, Hossein

    1999-05-01

    Described is an organic synthesis experiment that demonstrates the electronic transmission by substituents. The effect of substitution at the para-position of the styryl ring of 1,3-diphenyl-2-propenones (chalcones) by typical electron-donating or -accepting groups can be observed by proton and carbon-13 NMR spectroscopy. A linear correlation is observed when the differences in chemical shift measurements for H are plotted against the corresponding Hammett substituent constant values. Good correlation between carbon-13 chemical shifts of the alpha carbon are also observed. The syntheses of the 4-substituted chalcones is presented as well as a brief discussion of the theory.

  3. Innovative research on the group teaching mode based on the LabVIEW virtual environment

    NASA Astrophysics Data System (ADS)

    Liang, Pei; Huang, Jie; Gong, Hua-ping; Dong, Qian-min; Dong, Yan-yan; Sun, Cai-xia

    2017-08-01

    This paper discusses the widely existing problems of increasing demand of professional engineer in electronic science major and the backward of the teaching mode at present. From one specialized course "Virtual Instrument technique and LABVIEW programming", we explore the new group-teaching mode based on the Virtual Instrument technique, and then the Specific measures and implementation procedures and effect of this teaching mode summarized in the end.

  4. Marcus equation

    DOE R&D Accomplishments Database

    1998-09-21

    In the late 1950s to early 1960s Rudolph A. Marcus developed a theory for treating the rates of outer-sphere electron-transfer reactions. Outer-sphere reactions are reactions in which an electron is transferred from a donor to an acceptor without any chemical bonds being made or broken. (Electron-transfer reactions in which bonds are made or broken are referred to as inner-sphere reactions.) Marcus derived several very useful expressions, one of which has come to be known as the Marcus cross-relation or, more simply, as the Marcus equation. It is widely used for correlating and predicting electron-transfer rates. For his contributions to the understanding of electron-transfer reactions, Marcus received the 1992 Nobel Prize in Chemistry. This paper discusses the development and use of the Marcus equation. Topics include self-exchange reactions; net electron-transfer reactions; Marcus cross-relation; and proton, hydride, atom and group transfers.

  5. Ynamides in Ring Forming Transformations

    PubMed Central

    WANG, XIAO-NA; YEOM, HYUN-SUK; FANG, LI-CHAO; HE, SHUZHONG; MA, ZHI-XIONG; KEDROWSKI, BRANT L.; HSUNG, RICHARD P.

    2013-01-01

    Conspectus The ynamide functional group activates carbon-carbon triple bonds through an attached nitrogen atom that bears an electron-withdrawing group. As a result, the alkyne has both electrophilic and nucleophilic properties. Through the selection of the electron-withdrawing group attached to nitrogen chemists can modulate the electronic properties and reactivity of ynamides, making these groups versatile synthetic building blocks. The reactions of ynamides also lead directly to nitrogen-containing products, which provides access to important structural motifs found in natural products and molecules of medicinal interest. Therefore, researchers have invested increasing time and research in the chemistry of ynamides in recent years. This Account surveys and assesses new organic transformations involving ynamides developed in our laboratory and in others around the world. We showcase the synthetic power of ynamides for rapid assembly of complex molecular structures. Among the recent reports of ynamide transformations, ring-forming reactions provide a powerful tool for generating molecular complexity quickly. In addition to their synthetic utility, such reactions are mechanistically interesting. Therefore, we focus primarily on the cyclization chemistry of ynamides. This Account highlights ynamide reactions that are useful in the rapid synthesis of cyclic and polycyclic structural manifolds. We discuss the mechanisms active in the ring formations and describe representative examples that demonstrate the scope of these reactions and provide mechanistic insights. In this discussion we feature examples of ynamide reactions involving radical cyclizations, ring-closing metathesis, transition metal and non-transition metal mediated cyclizations, cycloaddition reactions, and rearrangements. The transformations presented rapidly introduce structural complexity and include nitrogen within, or in close proximity to, a newly formed ring (or rings). Thus, ynamides have emerged as powerful synthons for nitrogen-containing heterocycles and nitrogen-substituted rings, and we hope this Account will promote continued interest in the chemistry of ynamides. PMID:24164363

  6. Physical characterization of uranium oxide pellets and powder applied in the Nuclear Forensics International Technical Working Group Collaborative Materials Exercise 4

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Griffiths, Grant; Keegan, E.; Young, E.

    Physical characterization is one of the most broad and important categories of techniques to apply in a nuclear forensic examination. Physical characterization techniques vary from simple weighing and dimensional measurements to complex sample preparation and scanning electron microscopy-electron backscatter diffraction analysis. This paper reports on the physical characterization conducted by several international laboratories participating in the fourth Collaborative Materials Exercise, organized by the Nuclear Forensics International Technical Working Group. Methods include a range of physical measurements, microscopy-based observations, and profilometry. In conclusion, the value of these results for addressing key investigative questions concerning two uranium dioxide pellets and a uraniummore » dioxide powder is discussed.« less

  7. Physical characterization of uranium oxide pellets and powder applied in the Nuclear Forensics International Technical Working Group Collaborative Materials Exercise 4

    DOE PAGES

    Griffiths, Grant; Keegan, E.; Young, E.; ...

    2018-01-06

    Physical characterization is one of the most broad and important categories of techniques to apply in a nuclear forensic examination. Physical characterization techniques vary from simple weighing and dimensional measurements to complex sample preparation and scanning electron microscopy-electron backscatter diffraction analysis. This paper reports on the physical characterization conducted by several international laboratories participating in the fourth Collaborative Materials Exercise, organized by the Nuclear Forensics International Technical Working Group. Methods include a range of physical measurements, microscopy-based observations, and profilometry. In conclusion, the value of these results for addressing key investigative questions concerning two uranium dioxide pellets and a uraniummore » dioxide powder is discussed.« less

  8. Scaffolding scientific discussion using socially relevant representations in networked multimedia

    NASA Astrophysics Data System (ADS)

    Hoadley, Christopher M.

    1999-11-01

    How do students make use of social cues when learning on the computer? This work examines how students in a middle-school science course learned through on-line peer discussion. Cognitive accounts of collaboration stress interacting with ideas, while socially situated accounts stress the interpersonal context. The design of electronic environments allows investigation into the interrelation of cognitive and social dimensions. I use on-line peer discussion to investigate how socially relevant representations in interfaces can aid learning. First, I identify some of the variables that affect individual participation in on-line discussion, including interface features. Individual participation is predicted by student attitudes towards learning from peers. Second, I describe the range of group outcomes for these on-line discussions. There is a large effect of discussion group on learning outcomes which is not reducible to group composition or gross measures of group process. Third, I characterize how students (individually) construct understanding from these group discussions. Learning in the on-line discussions is shown to be a result of sustained interaction over time, not merely encountering or expressing ideas. Experimental manipulations in the types of social cues available to students suggest that many students do use socially relevant representations to support their understanding of multiple viewpoints and science reasoning. Personalizing scientific disputes can afford reflection on the nature of scientific discovery and advance. While there are many individual differences in how social representations are used by students in learning, overall learning benefits for certain social representations can be shown. This work has profound implications for design of collaborative instructional methods, equitable access to science learning, design of instructional technology, and understanding of learning and cognition in social settings.

  9. Use of the Internet for educational applications in prosthodontics.

    PubMed

    van Putten, M C

    1996-08-01

    Internet is the common term for the information superhighway. The Internet has become a major information resource for educational, governmental, and business institutions. This article reviews the current operation of the Internet as a background for discussing educational opportunities for instruction in prosthodontics. Electronic mail, news groups, file transfer protocol, Gopher, and network navigators are discussed. The use of the World Wide Web for educational purposes by The Ohio State University College of Dentistry Department of Restorative and Prosthetic Dentistry is described.

  10. Using Instant Messaging Systems as a Platform for Electronic Voting

    NASA Astrophysics Data System (ADS)

    Meletiadou, Anastasia; Grimm, Rüdiger

    Many Instant Messaging (IM) systems like Skype or Spark offer ex tended services such as file sharing, VoIP, or a shared whiteboard. As the name suggests, IM applications are predominantly used for spontaneous text-based communication for private or business purposes. In this paper we explore their potential to serve as platforms for secure collaborative applications like electronic contract negotiation, e-payment or electronic voting. Such applications have to deal with challenges like time constraints (“instant” com munication is desired), integration of media channels and the absence of one uni fying “sphere of control” covering all participants. In this paper, we address these challenges by discussing one particular secure collaborative application: secure decision processes for small groups. We provide the following contribu tions: (1) we define three varying scenarios and corresponding security require ments (2) we present an IM-based architecture implementing these scenarios, in cluding a Video-based authentication mechanism, and (3) we discuss poten tial attack patterns.

  11. Strategies for Multi-Modal Analysis

    NASA Astrophysics Data System (ADS)

    Hexemer, Alexander; Wang, Cheng; Pandolfi, Ronald; Kumar, Dinesh; Venkatakrishnan, Singanallur; Sethian, James; Camera Team

    This section on soft materials will be dedicated to discuss the extraction of the chemical distribution and spatial arrangement of constituent elements and functional groups at multiple length scales and, thus, the examination of collective dynamics, transport, and electronic ordering phenomena. Traditional measures of structure in soft materials have relied heavily on scattering and imaging based techniques due to their capacity to measure nanoscale dimensions and their capacity to monitor structure under conditions of dynamic stress loading. Special attentions are planned to focus on the application of resonant x-ray scattering, contrast-varied neutron scattering, analytical transmission electron microscopy, and their combinations. This session aims to bring experts in both scattering and electron microscope fields to discuss recent advances in selectively characterizing structural architectures of complex soft materials, which have often multi-components with a wide range of length scales and multiple functionalities, and thus hopes to foster novel ideas to decipher a higher level of structural complexity in soft materials in future. CAMERA, Early Career Award.

  12. Using an online service for breastfeeding support: what mothers want to discuss.

    PubMed

    Cowie, Genevieve A; Hill, Sophie; Robinson, Priscilla

    2011-08-01

    There is little research on how the establishment and maintenance of breastfeeding and other early parenting skills is assisted by the use of electronic peer support groups. In what ways do parents use a popular peer-moderated online resource and what topics do they choose to discuss? The objective of this study was to identify and quantify the main uses of an electronic discussion board hosted by a prominent Australian lay breastfeeding advocacy organisation. Three consecutive days of conversations on the discussion board were followed. Using content analysis, the messages were coded and analysed statistically for the ways the board was used and which topics were and were not present. The discussion board almost universally gave emotional support to the participants and most users expressed their emotions in their messages. The giving of factual advice or opinions was a much less frequent use of the discussion board as was the clear seeking of emotional support and general facts or advice. The range of topics discussed was dominated by general parenting followed by various breastfeeding topics as well as much discussion related to general social support. The lay-moderated discussion board can be a worthwhile resource for parents in need of reassurance, information or general social support. It may also be useful to expand the amount of breastfeeding and parenting information available on the organisation's main website.

  13. Building Your Own Web Course: The Case for Off-the-Shelf Component Software.

    ERIC Educational Resources Information Center

    Kaplan, Howard

    1998-01-01

    Compares the features, advantages, and disadvantages of two major software options available for designing web courses: (1) component, off-the shelf software that allows for creation of audio slide lectures, course materials, discussion forums, animations, synchronous chat groups, quiz creators, and electronic mail, and (2) integrated packages…

  14. Virtual Seminars and Their Impact on the Role of the Teaching Staff.

    ERIC Educational Resources Information Center

    Jelfs, Anne; Colbourn, Chris

    2002-01-01

    Discusses current demands on teaching staff in United Kingdom higher education and the impact these demands have when teaching through electronic resources. Topics include collaborative small-group learning; transferable skills; nontraditional students; the role of the tutor; social theories of education; and a case study of virtual seminars for…

  15. Computers and Information Systems in Planning and Related Governmental Functions.

    ERIC Educational Resources Information Center

    Tucker, Dorothy; Vance, Mary, Ed.

    The 266 items cited include material published since July 1960, organized in the following ten groups: (1) general discussion, and feasibility; (2) statewide electronic data processing (EDP) systems; (3) EDP in local governments; (4) intergovernmental EDP systems; (5) EDP in the planning agency; (6) data banks and information systems; (7) computer…

  16. Tracing the Reflective Practices of Student Teachers in Online Modes

    ERIC Educational Resources Information Center

    Farr, Fiona; Riordan, Elaine

    2015-01-01

    During the course of pre-and in-service teacher education programmes, reflection can happen in a number of ways, for example: reflective journals, personal stories and pair/group co-operative discussions, professional development portfolios, and blogs and electronic portfolios. The aim of this paper is to examine various technologies such as…

  17. One-Dimensional Nanostructures and Devices of II–V Group Semiconductors

    PubMed Central

    2009-01-01

    The II–V group semiconductors, with narrow band gaps, are important materials with many applications in infrared detectors, lasers, solar cells, ultrasonic multipliers, and Hall generators. Since the first report on trumpet-like Zn3P2nanowires, one-dimensional (1-D) nanostructures of II–V group semiconductors have attracted great research attention recently because these special 1-D nanostructures may find applications in fabricating new electronic and optoelectronic nanoscale devices. This article covers the 1-D II–V semiconducting nanostructures that have been synthesized till now, focusing on nanotubes, nanowires, nanobelts, and special nanostructures like heterostructured nanowires. Novel electronic and optoelectronic devices built on 1-D II–V semiconducting nanostructures will also be discussed, which include metal–insulator-semiconductor field-effect transistors, metal-semiconductor field-effect transistors, andp–nheterojunction photodiode. We intent to provide the readers a brief account of these exciting research activities. PMID:20596452

  18. K-12 access to internet: Securing the legal framework

    NASA Astrophysics Data System (ADS)

    Blauassociate, Andrew

    1993-09-01

    While many people in government, education, and industry have lauded the potential educational value of Internet access for students in grades K-12, there is as yet no legal or regulatory framework within which this new medium is being offered to students. The Communications Policy Forum, a nonpartisan project of the Electronic Frontier Foundation, recently convened a roundtable to discuss some of the legal issues that arise when K-12 schools provide Internet access to their students. Approximately 15 people, representing carriers who provide connections to the Internet, schools or school systems who are connected to the Internet, and legal experts with expertise in this and related areas, met to discuss questions of legal liability as this new medium enters an educational setting for minors. The following attempts to capture the major issues, suggestions, and directions for further collaborative efforts raised during the course of that discussion. In brief, the group identified statutory language aimed at other types of electronic communication that may offer some guidance; was briefed on a host of state laws that could be used to prosecute providers of certain materials found on the Internet; and concluded that there is no case law that clearly applies to this setting. The discussion revealed an interest in anticipating issues and developing responses before problems arose, and the need for shared approaches to allow carriers to move forward in serving and expanding this field. Members of the group offered to pursue these issues jointly and agreed upon a handful of concrete steps for further exploration and discussion.

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samskog, P.; Kispert, L.D.; Lund, A.

    Three different radicals were identified by EPR in x-ray irradiated single crystals of trehalose at 3 K. The species are the trapped electron, a hydroxy alkyl radical, and an alkoxy radical. The electron is trapped in an intermolecular site formed by two hydroxyl groups, one on the carbohydrate and the other on a water molecule as evidenced by the anisotropic proton hyperfine couplings. A geometric model for the trapping site is presented. The trapped electron decays by cleavage of an OH bond and the liberated hydrogen atom abstracts another hydrogen atom from an adjacent carbon atom forming a hydroxy alkylmore » radical. The site of the alkoxy radical has been identified. The primary reaction mechanism is discussed.« less

  20. Using Hyperfine Structure to Quantify the Effects of Substitution on the Electron Distribution Within a Pyridine Ring: a Study of 2-, 3-, and 4-PICOLYLAMINE

    NASA Astrophysics Data System (ADS)

    McDivitt, Lindsey M.; Himes, Korrina M.; Bailey, Josiah R.; McMahon, Timothy J.; Bird, Ryan G.

    2017-06-01

    The ground state rotational spectra of the three methylamine substituted pyridines, 2-, 3-, and 4-picolylamine, were collected and analyzed over the frequency range of 7-17.5 GHz using chirped-pulsed Fourier transform microwave spectroscopy. All three molecules show a distinctive quadrupole splitting, which is representative of the local electronic environment around the two different ^{14}N nuclei, with the pyridine nitrogen being particularly sensitive to the pi-electron distribution within the ring. The role that the position of the methylamine group plays on the quadrupole coupling constants on both nitrogens will be discussed and compared to other substituted pyridines.

  1. Undergraduate nurses reflections on Whatsapp use in improving primary health care education.

    PubMed

    Willemse, Juliana J

    2015-08-13

    The global use of mobile devices with their connectivity capacity, and integrated with the affordances of social media networks, provides a resource-rich platform for innovative student-directed learning experiences. The objective of this study was to review the experiences of undergraduate nurses on the improvement of primary health care education at a School of Nursing at a University in the Western Cape, South Africa, through the incorporation of a social media application, WhatsApp. A qualitative, exploratory, descriptive, and contextual design was used to explore and describe data collected from a purposive sample of 21 undergraduate nursing students. The study population was engaged in a WhatsApp discussion group to enhance their integration of theory and clinical practice of the health assessment competency of the Primary Health Care Module. Participants submitted electronic reflections on their experiences in the WhatsApp discussion group via email on completion of the study. Thematic analysis of the qualitative data collected was done according to Tesch's (1990) steps of descriptive data analysis in order to identify the major themes in the study. The electronic reflections were analysed to explore their rich, reflective data. Seven themes were identified that included: positive experiences using the WhatsApp group; the usefulness of WhatsApp for integrating theory and clinical practice; the availability of resources for test preparation; opportunity for clarification; anonymity; exclusion of students as a result of the lack of an appropriate device, and the application caused the battery of the device to run flat quickly. The results of the experiences of students in the WhatsApp discussion group could be used to inform the use of social media applications in teaching and learning, with the purpose of enhancing the integration of the theory and clinical practice.

  2. A Microcontroller Operated Device for the Generation of Liquid Extracts from Conventional Cigarette Smoke and Electronic Cigarette Aerosol.

    PubMed

    Anderson, Chastain A; Bokota, Rachael E; Majeste, Andrew E; Murfee, Walter L; Wang, Shusheng

    2018-01-18

    Electronic cigarettes are the most popular tobacco product among middle and high schoolers and are the most popular alternative tobacco product among adults. High quality, reproducible research on the consequences of electronic cigarette use is essential for understanding emerging public health concerns and crafting evidence based regulatory policy. While a growing number of papers discuss electronic cigarettes, there is little consistency in methods across groups and very little consensus on results. Here, we describe a programmable laboratory device that can be used to create extracts of conventional cigarette smoke and electronic cigarette aerosol. This protocol details instructions for the assembly and operation of said device, and demonstrates the use of the generated extract in two sample applications: an in vitro cell viability assay and gas-chromatography mass-spectrometry. This method provides a tool for making direct comparisons between conventional cigarettes and electronic cigarettes, and is an accessible entry point into electronic cigarette research.

  3. The US Nuclear Data Network

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1993-10-19

    This report discusses the following topics: US Nuclear Data Network Meeting; TUNL A=3--20 Data Project Activity Report 1993; INEL Mass-chain Evaluation Project Activity Report for 1993; 1993 Isotopes; Nuclear Data Project Activity Report; The NNDC Activity Report Parts A and B; Minutes of the Formats and Procedures Subcommittee; Evaluation of High-spin Nuclear Data for ENSDF and Table of Superdeformed Nuclear Bands; Proposal for Support of a Experimental High-spin; Data File/Data-Network Coordinator; Radioactive Decay and Applications; A Plan for a Horizontal Evaluation of Decay Data; ENSDF On-line System; The MacNuclide Project Expanding the Scope of the Nuclear Structure Reference File; ENSDAT:more » Evaluated Nuclear Structure Drawings and Tables; Cross Section Evaluation Working Group (CSEWG) and CSEWG Strategy Session; A Draft Proposal for a USNDN Program Advisory Council; Recommendations of Focus Group 1; Recommendations of Focus Group 2; Recommendations of Focus Group 3; Recommendations of Focus Group 4; The Table of Isotopes; The Isotopes CD-ROM; Electronic Table of Isotopes (ETOI); and Electronic Access to Nuclear Data.« less

  4. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Badnell, N. R.; Ballance, C. P.

    Modeling the spectral emission of low-charge iron group ions enables the diagnostic determination of the local physical conditions of many cool plasma environments such as those found in H II regions, planetary nebulae, active galactic nuclei, etc. Electron-impact excitation drives the population of the emitting levels and, hence, their emissivities. By carrying-out Breit-Pauli and intermediate coupling frame transformation (ICFT) R-matrix calculations for the electron-impact excitation of Fe{sup 2+}, which both use the exact same atomic structure and the same close-coupling expansion, we demonstrate the validity of the application of the powerful ICFT method to low-charge iron group ions. This ismore » in contradiction to the finding of Bautista et al., who carried-out ICFT and Dirac R-matrix calculations for the same ion. We discuss possible reasons.« less

  5. Use of an Electronic Tongue System and Fuzzy Logic to Analyze Water Samples

    NASA Astrophysics Data System (ADS)

    Braga, Guilherme S.; Paterno, Leonardo G.; Fonseca, Fernando J.

    2009-05-01

    An electronic tongue (ET) system incorporating 8 chemical sensors was used in combination with two pattern recognition tools, namely principal component analysis (PCA) and Fuzzy logic for discriminating/classification of water samples from different sources (tap, distilled and three brands of mineral water). The Fuzzy program exhibited a higher accuracy than the PCA and allowed the ET to classify correctly 4 in 5 types of water. Exception was made for one brand of mineral water which was sometimes misclassified as tap water. On the other hand, the PCA grouped water samples in three clusters, one with the distilled water; a second with tap water and one brand of mineral water, and the third with the other two other brands of mineral water. Samples in the second and third clusters could not be distinguished. Nevertheless, close grouping between repeated tests indicated that the ET system response is reproducible. The potential use of the Fuzzy logic as the data processing tool in combination with an electronic tongue system is discussed.

  6. Spin Andreev-like Reflection in Metal-Mott Insulator Heterostructures

    DOE PAGES

    Al-Hassanieh, K. A.; Rincón, Julián; Alvarez, G.; ...

    2015-02-09

    Here we used the time-dependent density-matrix renormalization group (tDMRG) to study the time evolution of electron wave packets in one-dimensional (1D) metal-superconductor heterostructures. The results show Andreev reflection at the interface, as expected. By combining these results with the well-known single- spin-species electron-hole transformation in the Hubbard model, we predict an analogous spin Andreev reflection in metal-Mott insulator heterostructures. This effect is numerically confirmed using 1D tDMRG, but it is expected to also be present in higher dimensions, as well as in more general Hamiltonians. We present an intuitive picture of the spin reflection, analogous to that of Andreev reflectionmore » at metal- superconductor interfaces. This allows us to discuss a novel antiferromagnetic proximity effect. Possible experimental realizations are discussed.« less

  7. Use of an Electronic Discussion Group for High School Publications Advisers: A Descriptive Pilot Study.

    ERIC Educational Resources Information Center

    Blick, Eddie

    This study aimed to catalog the nature of written message exchanges on a network computer bulletin board, HSJOURN, which caters mainly to high school journalism teachers and publications advisers. The study analyzed the content of messages between December 1993 and January 1995 and cataloged them in the following categories: announcements;…

  8. Public Access; Public Interest. The Network Project. Notebook Number 11.

    ERIC Educational Resources Information Center

    Columbia Univ., New York, NY. Network Project.

    The transcript of a panel discussion and an essay on public access to and control of society's information resources are presented. It is contended that the electronic Media--including radio, television, and communication satellites--are controlled by a select group of individuals and corporations and that they are not meeting the public interest.…

  9. Contemporary Performance by and for Those with Disabilities: The Case of Greece

    ERIC Educational Resources Information Center

    Koltsida, Maria; Lenakakis, Antonis

    2017-01-01

    The purpose of this article is to discuss examples of Greek contemporary performance by and for individuals with disabilities and by mixed groups that include individuals with and without disabilities working together. It is a research on primary and secondary electronic and printed resources and data. This article examines firstly the state…

  10. A Study of the Communication Patterns of Participants in Consumer Health Electronic Discussion Groups.

    ERIC Educational Resources Information Center

    Schoch, Natalie A.; White, Marilyn Domas

    1997-01-01

    Compares the interactions in two listservs, one dealing with a chronic illness (diabetes), the other with a more acute disease (colon cancer). Analysis of 1000 messages from each list categorized messages by problem orientation and into socioemotional areas having positive and negative reactions and into task areas for asking questions and…

  11. Addressing Common Student Errors with Classroom Voting in Multivariable Calculus

    ERIC Educational Resources Information Center

    Cline, Kelly; Parker, Mark; Zullo, Holly; Stewart, Ann

    2012-01-01

    One technique for identifying and addressing common student errors is the method of classroom voting, in which the instructor presents a multiple-choice question to the class, and after a few minutes for consideration and small group discussion, each student votes on the correct answer, often using a hand-held electronic clicker. If a large number…

  12. Patient engagement in the inpatient setting: a systematic review.

    PubMed

    Prey, Jennifer E; Woollen, Janet; Wilcox, Lauren; Sackeim, Alexander D; Hripcsak, George; Bakken, Suzanne; Restaino, Susan; Feiner, Steven; Vawdrey, David K

    2014-01-01

    To systematically review existing literature regarding patient engagement technologies used in the inpatient setting. PubMed, Association for Computing Machinery (ACM) Digital Library, Institute of Electrical and Electronics Engineers (IEEE) Xplore, and Cochrane databases were searched for studies that discussed patient engagement ('self-efficacy', 'patient empowerment', 'patient activation', or 'patient engagement'), (2) involved health information technology ('technology', 'games', 'electronic health record', 'electronic medical record', or 'personal health record'), and (3) took place in the inpatient setting ('inpatient' or 'hospital'). Only English language studies were reviewed. 17 articles were identified describing the topic of inpatient patient engagement. A few articles identified design requirements for inpatient engagement technology. The remainder described interventions, which we grouped into five categories: entertainment, generic health information delivery, patient-specific information delivery, advanced communication tools, and personalized decision support. Examination of the current literature shows there are considerable gaps in knowledge regarding patient engagement in the hospital setting and inconsistent use of terminology regarding patient engagement overall. Research on inpatient engagement technologies has been limited, especially concerning the impact on health outcomes and cost-effectiveness. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. The study of electrochemical cell taught by problem-based learning

    NASA Astrophysics Data System (ADS)

    Srichaitung, Paisan

    2018-01-01

    According to the teaching activity of Chemistry, researcher found that students were not able to seek self knowledge even applied knowledge to their everyday life. Therefore, the researcher is interested in creating an activity to have students constructed their knowledge, science process skills, and can apply knowledge in their everyday life. The researcher presented form of teaching activity of electrochemical cell by using problem-based learning for Mathayom five students of Thai Christian School. The teaching activity focused on electron transfer in galvanic cell. In this activity, the researcher assigned students to design the electron transfer in galvanic cell using any solution that could light up the bulb. Then students were separated into a group of two, which were total seven groups. Each group of students searched the information about the electron transfer in galvanic cell from books, internet, or other sources of information. After students received concepts, or knowledge they searched for, Students designed and did the experiment. Finally, the students in each groups had twenty minutes to give a presentation in front of the classroom about the electron transfer in galvanic using any solution to light up the bulb with showing the experiment, and five minutes to answer their classmates' questions. Giving the presentation took four periods with total seven groups. After students finished their presentation, the researcher had students discussed and summarized the teaching activity's main idea of electron transfer in galvanic. Then, researcher observed students' behavior in each group found that 85.7 percentages of total students developed science process skills, and transferred their knowledge through presentation completely. When students done the post test, the researcher found that 92.85 percentages of total students were able to explain the concept of galvanic cell, described the preparation and the selection of experimental equipment. Furthermore, students constructed their skills, scientific process, and seek self knowledge which made them seek the choices to solve problems variously. This Research using problem-based learning can be applied to teaching activity in other subjects.

  14. Increasing Discussion Rates of Incontinence in Primary Care: A Randomized Controlled Trial.

    PubMed

    Schüssler-Fiorenza Rose, Sophia Miryam; Gangnon, Ronald E; Chewning, Betty; Wald, Arnold

    2015-11-01

    A minority of women with urinary incontinence (UI) and even fewer with fecal incontinence (FI) report having discussed it with a health care provider in the past year. Thus our aim was to evaluate whether the use of an electronic pelvic floor assessment questionnaire (ePAQ-PF) improves communication about incontinence in primary care. Women 40 years and older who were scheduled for an annual wellness physical at an internal medicine clinic between August 2007 and August 2008 were randomized to complete the ePAQ-PF prior to (n = 145) or after (n = 139) their visit. Clinicians of women in the intervention group received the ePAQ-PF report prior to the visit. Outcome measures from clinic note abstraction included mention of UI (primary) and FI. Participant-reported outcome measures included discussion of UI and FI and initiator of discussion. Discussions of UI was more common in the intervention group than the control group: (27% vs. 19%; odds ratio [OR], 1.6 95% confidence interval [95%CI] 0.9-2.8, particularly for women over 60 (33% vs. 12%; OR 3.8, 95%CI 1.2-11.8) and for women with UI (42% vs. 25%; OR 2.2, 95%CI 1.1-4.1). The intervention primarily led to an increase in clinician-initiated UI discussions which were more common in the intervention group (18% vs. 4%, OR 4.8, 95%CI 1.9-12.0) Participants in the intervention group more frequently reported discussion of FI (14% vs. 6%; OR 2.5, 95%CI 1.1-6.0) which was clinician initiated in over half the cases (9% vs. 3%; OR 3.5, 95%CI 1.1-11.0). Use of the ePAQ-PF prior to clinic visits increases discussion of UI and FI, particularly clinician-initiated discussion. These findings suggest that such instruments may increase the detection and treatment of this often "silent" affliction.

  15. Collaborative designing and job satisfaction of airplane manufacturing engineers: A case study

    NASA Astrophysics Data System (ADS)

    Johnson, Michael David, Sr.

    The group III-nitride system of materials has had considerable commercial success in recent years in the solid state lighting (SSL) and power electronics markets. The need for high efficient general lighting applications has driven research into InGaN based blue light emitting diodes (LEDs), and demand for more efficient power electronics for telecommunications has driven research into AlGaN based high electron mobility transistors (HEMTs). However, the group III-nitrides material properties make them attractive for several other applications that have not received as much attention. This work focuses on developing group III-nitride based devices for novel applications. GaN is a robust, chemically inert, piezoelectric material, making it an ideal candidate for surface acoustic wave (SAW) devices designed for high temperature and/or harsh environment sensors. In this work, SAW devices based on GaN are developed for use in high temperature gas or chemical sensor applications. To increase device sensitivity, while maintaining a simple one-step photolithography fabrication process, devices were designed to operate at high harmonic frequencies. This allows for GHz regime operation without sub-micron fabrication. One potential market for this technology is continuous emissions monitoring of combustion gas vehicles. In addition to SAW devices, high electron mobility transistors (HEMTs) were developed. The epitaxial structure was characterized and the 2-D electron gas concentrations were simulated and compared to experimental results. Device fabrication processes were developed and are outlined. Fabricated devices were electrically measured and device performance is discussed.

  16. Theoretical analysis of the electronic properties of the sex pheromone and its analogue derivatives in the female processionary moth Thaumetopoea pytiocampa.

    PubMed

    Chamorro, Ester R; Sequeira, Alfredo F; Zalazar, M Fernanda; Peruchena, Nélida M

    2008-09-15

    In the present work, the distribution of the electronic charge density of the natural sex pheromone, the (Z)-13-hexadecen-11-ynyl acetate, in the female processionary moth, Thaumetopoea pytiocampa, and its nine analogue derivatives was studied within the framework of the Density Functional Theory and the Atoms in Molecules (AIM) Theory at B3LYP/6-31G *//B3LYP/6-31++G * * level. Additionally, molecular electrostatic potential (MEP) maps of the previously mentioned compounds were computed and compared. Furthermore, the substitution of hydrogen atoms from the methyl group in the acetate group by electron withdrawing substituents (i.e., halogen atoms) as well as the replacement effect of hydrogen by electron donor substituents (+I effect) as methyl group, were explored. The key feature of the topological distribution of the charge density in analogue compounds, such as the variations of the topological properties encountered in the region formed by neighbouring atoms from the substitution site were presented and discussed. Using topological parameters, such as electronic charge density, Laplacian, kinetic energy density, and potential energy density evaluated at bond critical points (BCP), we provide here a detailed analysis of the nature of the chemical bonding of these molecules. In addition, the atomic properties (population, charge, energy, volume, and dipole moment) were determined on selected atoms. These properties were analyzed at the substitution site (with respect to the natural sex pheromone) and related to the biological activity and to the possible binding site with the pheromone binding protein, (PBP). Moreover, the Laplacian function of the electronic density was used to locate electrophilic regions susceptible to be attacked (by deficient electron atoms or donor hydrogen). Our results indicate that the change in the atomic properties, such as electronic population and atomic volume, are sensitive indicators of the loss of the biological activity in the analogues studied here. The crucial interaction between the acetate group of the natural sex pheromone and the PBP is most likely to be a hydrogen bonding and the substitution of hydrogen atoms by electronegative atoms in the pheromone molecule reduces the hydrogen acceptor capacity. This situation is mirrored by the diminish of the electronic population on carbon and oxygen atoms at the carbonylic group in the halo-acetate group. Additionally, the modified acetate group (with electronegative atoms) shows new charge concentration critical points or regions of concentration of charge density in which an electrophilic attack can also occur. Finally, the use of the topological analysis based in the charge density distribution and its Laplacian function, in conjunction with MEP maps provides valuable information about the steric volume and electronic requirement of the sex pheromone for binding to the PBP.

  17. Doping of TiO 2 Polymorphs for Altered Optical and Photocatalytic Properties

    DOE PAGES

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; ...

    2009-01-01

    Tmore » his paper reviews recent investigations of the influence of dopants on the optical properties of iO 2 polymorphs. he common undoped polymorphs of iO 2 are discussed and compared. he results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of the iO 2 electronic structure, which is supported with first-principles calculations.« less

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mechalakos, J.

    The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiationmore » therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy.« less

  19. Insights into the mechanisms of vertical transmission of HIV-1. BIOMED2 Working Group on the in utero transmission of HIV-1.

    PubMed

    Menu, E; Mognetti, B; Moussa, M; Nardese, V; Tresoldi, L; Tscherning, C; Mbopi Keou, F X; Dubanchet, S; Mauclere, P; Fenyö, E M; Scarlatti, G; Barre-Sinoussi, F; Chaouat, G

    1997-12-01

    This paper is a summary of three oral presentations, as well as the ensuing discussion, at the Rijeka/Opatija 3rd Alps Adria Immunology meeting by three members of the European Biomed group on vertical transmission of HIV (G. Chaouat, F. Barre-Sinoussi, G. Scarlatti). This group also involves the laboratories of D. Dormont (CEA, Fontenay aux roses, France), P. Gounon (Electron Microscopy, the Pasteur Institute, France; Irène Athanassakis, University of Crete, Greece; Eva Maria Fenyö, Karolinska Institute, Sweden; and Larry Guilbert, Canada). As such, this paper intends to be neither a review, nor an original article, but rather is an opinion paper discussing the working hypothesis of this network, as well as some of their recent results, which were presented at this meeting. The paper was issued at the request of the organizers of the meeting.

  20. Structural, vibrational, electronic investigations and quantum chemical studies of 2-amino-4-methoxybenzothiazole

    NASA Astrophysics Data System (ADS)

    Arjunan, V.; Raj, Arushma; Santhanam, R.; Marchewka, M. K.; Mohan, S.

    2013-02-01

    Extensive vibrational investigations of 2-amino-4-methoxybenzothiazole have been carried out with FTIR and FT-Raman spectral techniques. The electronic structure of the molecule has been analysed by UV-Visible and NMR spectroscopies. The DFT studies were carried out with B3LYP and HF methods utilising 6-31G(d,p), 6-311++G(d,p) and cc-pVDZ basis sets to determine the structural, thermodynamical, vibrational, electronic characteristics of the compound and also to understand the electronic and steric influence of the methoxy amino groups on the skeletal frequencies. The mixing of the fundamental modes was determined with the help of total energy distribution (TED). The energies of the frontier molecular orbitals have also been determined. The kinetic and thermodynamic stability and chemical hardness of the molecule have been determined. Complete NBO analysis was also carried out to find out the intramolecular electronic interactions and their stabilisation energy. 1H and 13C NMR chemical shifts and the electronic transitions of the molecule are also discussed.

  1. The diagnosis related groups enhanced electronic medical record.

    PubMed

    Müller, Marcel Lucas; Bürkle, Thomas; Irps, Sebastian; Roeder, Norbert; Prokosch, Hans-Ulrich

    2003-07-01

    The introduction of Diagnosis Related Groups as a basis for hospital payment in Germany announced essential changes in the hospital reimbursement practice. A hospital's economical survival will depend vitally on the accuracy and completeness of the documentation of DRG relevant data like diagnosis and procedure codes. In order to enhance physicians' coding compliance, an easy-to-use interface integrating coding tasks seamlessly into clinical routine had to be developed. A generic approach should access coding and clinical guidelines from different information sources. Within the Electronic Medical Record (EMR) a user interface ('DRG Control Center') for all DRG relevant clinical and administrative data has been built. A comprehensive DRG-related web site gives online access to DRG grouping software and an electronic coding expert. Both components are linked together using an application supporting bi-directional communication. Other web based services like a guideline search engine can be integrated as well. With the proposed method, the clinician gains quick access to context sensitive clinical guidelines for appropriate treatment of his/her patient and administrative guidelines for the adequate coding of the diagnoses and procedures. This paper describes the design and current implementation and discusses our experiences.

  2. Carbon Nanoelectronics

    NASA Astrophysics Data System (ADS)

    McEuen, Paul

    2001-05-01

    Recently, there has been tremendous interest in nanostructures built entirely out of carbon. The most famous are the soccer-ball shaped C60 molecule and single-walled nanotubes. The latter are nanometer-diameter cylinders made from rolled up single graphene sheets. These carbon nanostructures are proving to be wonderful systems for the study of the physics of electrons in reduced dimensions. They also have a variety of technological applications (both demonstrated and potential), in areas ranging from materials to electronics to biotechnology. In this talk, I will discuss our group's recent efforts to probe the electrical and electromechanical, and thermal properties of these fascinating systems. note

  3. Electrochemical Growth of Single-Crystal Metal Nanowires via a Two-Dimensional Nucleation and Growth Mechanism.

    PubMed

    Tian, Mingliang; Wang, Jinguo; Kurtz, James; Mallouk, Thomas E; Chan, M H W

    2003-07-01

    Metallic nanowires (Au, Ag, Cu, Ni, Co, and Rh) with an average diameter of 40 nm and a length of 3-5 μm have been fabricated by electrodeposition in the pores of track-etched polycarbonate membranes. Structural characterizations by transmission electron microscopy (TEM) and electron diffraction showed that nanowires of Au, Ag, and Cu are single-crystalline with a preferred [111] orientation, whereas Ni, Co, and Rh wires are polycrystalline. Possible mechanisms responsible for nucleation and growth for single-crystal noble metals versus polycrystalline group VIII-B metals are discussed.

  4. Substituent effects on the redox states of locally functionalized single-walled carbon nanotubes revealed by in situ photoluminescence spectroelectrochemistry.

    PubMed

    Shiraishi, Tomonari; Shiraki, Tomohiro; Nakashima, Naotoshi

    2017-11-09

    Single-walled carbon nanotubes (SWNTs) with local chemical modification have been recognized as a novel near infrared (NIR) photoluminescent nanomaterial due to the emergence of a new red-shifted photoluminescence (PL) with enhanced quantum yields. As a characteristic feature of the locally functionalized SWNTs (lf-SWNTs), PL wavelength changes occur with the structural dependence of the substituent structures in the modified aryl groups, showing up to a 60 nm peak shift according to an electronic property difference of the aryl groups. Up to now, however, the structural effect on the electronic states of the lf-SWNTs has been discussed only on the basis of theoretical calculations due to the very limited amount of modifications. Herein, we describe the successfully-determined electronic states of the aryl-modified lf-SWNTs with different substituents (Ar-X SWNTs) using an in situ PL spectroelectrochemical method based on electrochemical quenching of the PL intensities analyzed by the Nernst equation. In particular, we reveal that the local functionalization of (6,5)SWNTs induced potential changes in the energy levels of the HOMO and the LUMO by -23 to -38 meV and +20 to +22 meV, respectively, compared to those of the pristine SWNTs, which generates exciton trapping sites with narrower band gaps. Moreover, the HOMO levels of the Ar-X SWNTs specifically shift in a negative potential direction by 15 meV according to an enhancement of the electron-accepting property of the substituents in the aryl groups that corresponds to an increase in the Hammet substituent constants, suggesting the importance of the dipole effect from the aryl groups on the lf-SWNTs to the level shift of the frontier orbitals. Our method is a promising way to characterize the electronic features of the lf-SWNTs.

  5. Phase space holes and synchronized BGK modes in autoresonantly driven, Penning-trapped electron clouds

    NASA Astrophysics Data System (ADS)

    Friedland, Lazar; Fajans, Joel; Bertsche, Will; Wurtele, Jonathan

    2003-10-01

    We study excitation and control of BGK modes in pure electron plasmas in a Penning trap. We apply an oscillating external potential with a negatively chirped frequency. This drive resonates with, and phase-locks to, a group of axially bouncing electrons in the trap. All initially phase-locked electrons remain phase-locked during the chirp (the autoresonance phenomenon), while some new particles are added to the resonant group, as the bucket moves through the phase space. This creates an oscillating in space and slowly evolving in energy hole in the phase space distribution of the electrons. The electron density perturbation associated with this evolving hole yields a BGK mode synchronized with the drive. The local depth of the hole in phase space, and, thus, the amplitude of the mode are controlled by the external parameter (the driving frequency). The process is reversible, so that the BGK mode can be returned to its nearly initial state, by reversing the direction of variation of the driving frequency. A kinetic theory of this excitation process is developed. The theory uses results on passage through, and capture into, bounce resonance in the system from Monte Carlo simulations of resonant bucket dynamics. We discuss the dependence of the excited BGK mode on the drive frequency chirp rate and other plasma parameters and compare these predictions with experiments.

  6. Case study evaluating Just-In-Time Teaching and Peer Instruction using clickers in a quantum mechanics course

    NASA Astrophysics Data System (ADS)

    Sayer, Ryan; Marshman, Emily; Singh, Chandralekha

    2016-12-01

    Just-in-Time Teaching (JiTT) is an instructional strategy involving feedback from students on prelecture activities in order to design in-class activities to build on the continuing feedback from students. We investigate the effectiveness of a JiTT approach, which included in-class concept tests using clickers in an upper-division quantum mechanics course. We analyze student performance on prelecture reading quizzes, in-class clicker questions answered individually, and clicker questions answered after group discussion, and compare those performances with open-ended retention quizzes administered after all instructional activities on the same concepts. In general, compared to the reading quizzes, student performance improved when individual clicker questions were posed after lectures that focused on student difficulties found via electronic feedback. The performance on the clicker questions after group discussion following individual clicker question responses also showed improvement. We discuss some possible reasons for the improved performance at various stages, e.g., from prelecture reading quizzes to postlecture clicker questions, and from individual to group clicker questions.

  7. Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72.

    PubMed

    Beddar, A Sam; Biggs, Peter J; Chang, Sha; Ezzell, Gary A; Faddegon, Bruce A; Hensley, Frank W; Mills, Michael D

    2006-05-01

    Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT, (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems.

  8. Anion photoelectron spectroscopy of germanium and tin clusters containing a transition- or lanthanide-metal atom; MGe(n)- (n = 8-20) and MSn(n)- (n = 15-17) (M = Sc-V, Y-Nb, and Lu-Ta).

    PubMed

    Atobe, Junko; Koyasu, Kiichirou; Furuse, Shunsuke; Nakajima, Atsushi

    2012-07-14

    The electronic properties of germanium and tin clusters containing a transition- or lanthanide-metal atom from group 3, 4, or 5, MGe(n) (M = Sc, Ti, V, Y, Zr, Nb, Lu, Hf, and Ta) and MSn(n) (M = Sc, Ti, Y. Zr, and Hf), were investigated by anion photoelectron spectroscopy at 213 nm. In the case of the group 3 elements Sc, Y, and Lu, the threshold energy of electron detachment of MGe(n)(-) exhibits local maxima at n = 10 and 16, while in the case of the group 4 elements Ti, Zr, and Hf, it exhibits a local minimum only at n = 16, associated with the presence of a small bump in the spectrum. A similar behavior is observed for MSn(n)(-) around n = 16, and these electronic characteristics of MGe(n) and MSn(n) are closely related to those of MSi(n). Compared to MSi(n), however, the larger cavity size of a Ge(n) cage allows metal atom encapsulation at a smaller size n. A cooperative effect between the electronic and geometric structures of clusters with a large cavity of Ge(16) or Sn(16) is discussed together with the results of experiments that probe their geometric stability via their reactivity to H(2)O adsorption.

  9. THz-driven zero-slippage IFEL scheme for phase space manipulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Curry, E.; Fabbri, S.; Musumeci, P.

    In this paper, we describe an inverse free electron laser (IFEL) interaction driven by a near single-cycle THz pulse that is group velocity-matched to an electron bunch inside a waveguide, allowing for a sustained interaction in a magnetic undulator. We discuss the application of this guided-THz IFEL technique for compression of a relativistic electron bunch and synchronization with the external laser pulse used to generate the THz pulse via optical rectification, as well as a laser-driven THz streaking diagnostic with the potential for femtosecond scale temporal resolution. Initial measurements of the THz waveform via an electro-optic sampling based technique confirm the predicted reduction of the group velocity, using a curved parallel plate waveguide, as a function of the varying aperture size of the guide. We also present the design of a proof-of-principle experiment based on the bunch parameters available at the UCLA PEGASUS laboratory. With amore » $$10\\,\\mathrm{MV}\\,{{\\rm{m}}}^{-1}$$ THz peak field, our simulation model predicts compression of a $$6\\,\\mathrm{MeV}$$ $$100\\,\\mathrm{fs}$$ electron beam by nearly an order of magnitude and a significant reduction of its initial timing jitter.« less

  10. THz-driven zero-slippage IFEL scheme for phase space manipulation

    DOE PAGES

    Curry, E.; Fabbri, S.; Musumeci, P.; ...

    2016-11-24

    In this paper, we describe an inverse free electron laser (IFEL) interaction driven by a near single-cycle THz pulse that is group velocity-matched to an electron bunch inside a waveguide, allowing for a sustained interaction in a magnetic undulator. We discuss the application of this guided-THz IFEL technique for compression of a relativistic electron bunch and synchronization with the external laser pulse used to generate the THz pulse via optical rectification, as well as a laser-driven THz streaking diagnostic with the potential for femtosecond scale temporal resolution. Initial measurements of the THz waveform via an electro-optic sampling based technique confirm the predicted reduction of the group velocity, using a curved parallel plate waveguide, as a function of the varying aperture size of the guide. We also present the design of a proof-of-principle experiment based on the bunch parameters available at the UCLA PEGASUS laboratory. With amore » $$10\\,\\mathrm{MV}\\,{{\\rm{m}}}^{-1}$$ THz peak field, our simulation model predicts compression of a $$6\\,\\mathrm{MeV}$$ $$100\\,\\mathrm{fs}$$ electron beam by nearly an order of magnitude and a significant reduction of its initial timing jitter.« less

  11. The New Mass Media Challenge to a Free Society.

    ERIC Educational Resources Information Center

    Seldes, Gilbert

    Critical issues are raised for group study and discussion on the relationship of the thinking individual to the mass media. Although the electronic revolution is still in progress, it is essential to act now to control its speed and direction, using what is best in the media while trying to correct the faults. An analysis of fictional and factual…

  12. Multisite constrained model of trans-4-(N,N-dimethylamino)-4'-nitrostilbene for structural elucidation of radiative and nonradiative excited states.

    PubMed

    Lin, Cheng-Kai; Wang, Yu-Fu; Cheng, Yuan-Chung; Yang, Jye-Shane

    2013-04-18

    A constrained model compound of trans-4-(N,N-dimethylamino)-4'-nitrostilbene (DNS), namely, compound DNS-B3 that is limited to torsions about the phenyl-nitro C-N bond and the central C═C bond, was prepared to investigate the structural nature of the radiative and nonradiative states of electronically excited DNS. The great similarities in solvent-dependent electronic spectra, fluorescence decay times, and quantum yields for fluorescence (Φf) and trans → cis photoisomerization (Φtc) between DNS and DNS-B3 indicate that the fluorescence is from a planar charge-transfer state and torsion of the nitro group is sufficient to account for the nonradiative decay of DNS. This conclusion is supported by TDDFT calculations on DNS-B3 in dichloromethane. The structure at the conical intersection for internal conversion is associated with not only a twisting but also a pyramidalization of the nitro group. The mechanism of the NO2 torsion is discussed in terms of the effects of solvent polarity, the substituents, and the volume demand. The differences and analogies of the NO2- vs amino-twisted intramolecular charge-transfer (TICT) state of trans-aminostilbenes are also discussed.

  13. Nitroxides as Antioxidants and Anticancer Drugs

    PubMed Central

    Lewandowski, Marcin; Gwozdzinski, Krzysztof

    2017-01-01

    Nitroxides are stable free radicals that contain a nitroxyl group with an unpaired electron. In this paper, we present the properties and application of nitroxides as antioxidants and anticancer drugs. The mostly used nitroxides in biology and medicine are a group of heterocyclic nitroxide derivatives of piperidine, pyrroline and pyrrolidine. The antioxidant action of nitroxides is associated with their redox cycle. Nitroxides, unlike other antioxidants, are characterized by a catalytic mechanism of action associated with a single electron oxidation and reduction reaction. In biological conditions, they mimic superoxide dismutase (SOD), modulate hemoprotein’s catalase-like activity, scavenge reactive free radicals, inhibit the Fenton and Haber-Weiss reactions and suppress the oxidation of biological materials (peptides, proteins, lipids, etc.). The use of nitroxides as antioxidants against oxidative stress induced by anticancer drugs has also been investigated. The application of nitroxides and their derivatives as anticancer drugs is discussed in the contexts of breast, hepatic, lung, ovarian, lymphatic and thyroid cancers under in vivo and in vitro experiments. In this article, we focus on new natural spin-labelled derivatives such as camptothecin, rotenone, combretastatin, podophyllotoxin and others. The applications of nitroxides in the aging process, cardiovascular disease and pathological conditions were also discussed. PMID:29165366

  14. Nano-Electronics and Bio-Electronics

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Kwak, Dochan (Technical Monitor)

    2001-01-01

    Viewgraph presentation on Nano-Electronics and Bio-Electronics is discussed. Topics discussed include: NASA Ames nanotechnology program, Potential Carbon Nanotube (CNT) application, CNT synthesis,Computational Nanotechnology, and protein nanotubes.

  15. Case Study: Converting Paper-based Case Report Forms to an Electronic Format (e-CRF) with ACASI Self-Report Integration.

    PubMed

    Mierzwa, Stan; Souidi, Samir; Akello, Carolyne; Etima, Juliane; Ssebagala, Richard; Nolan, Monica; Kabwigu, Samuel; Nakablito, Clemensia

    2017-01-01

    This paper will discuss the integration of electronic Case Report Forms (e-CRFs) into an already existing Android-based Audio Computer-Assisted Self-Interview (ACASI) software solution that was developed for a public health project in Kampala, Uganda, the technical outcome results, and lessons learned that may be useful to other projects requiring or considering such a technology solution. The developed product can function without a connection to the Internet and allows for synchronizing collected data once connectivity is possible. Previously, only paper-based CRFs were utilized at the Uganda project site. A subset or select group of CRFs were targeted for integration with ACASI in order to test feasibility and success. Survey volume, error rate, and acceptance of the system, as well as the operational and technical design of the solution, will be discussed.

  16. The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand

    NASA Astrophysics Data System (ADS)

    Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.

    2017-06-01

    During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.

  17. The accuracy and efficiency of electronic screening for recruitment into a clinical trial on COPD.

    PubMed

    Schmickl, Christopher N; Li, Man; Li, Guangxi; Wetzstein, Marnie M; Herasevich, Vitaly; Gajic, Ognjen; Benzo, Roberto P

    2011-10-01

    Participant recruitment is an important process in successful conduct of randomized controlled trials. To facilitate enrollment into a National Institutes of Health-sponsored clinical trial involving patients with chronic obstructive pulmonary disease (COPD), we developed and prospectively validated an automated electronic screening tool based on boolean free-text search of admission notes in electronic medical records. During a 2-week validation period, all patients admitted to prespecified general medical services were screened for eligibility by both the electronic screening tool and a COPD nurse. Group discussion was the gold standard for confirmation of true-positive results. Compared with the gold standard, electronic screening yielded 100% sensitivity, 92% specificity, 100% negative predictive value, and 72% positive predictive value. Compared with traditional manual screening, electronic screening demonstrated time-saving potential of 76%. Thus, the electronic screening tool accurately identifies potential study subjects and improves efficiency of patient accrual for a clinical trial on COPD. This method may be expanded into other institutional and clinical settings. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Ultrastructure of antennal sensilla of the peach aphid Myzus persicae Sulzer, 1776.

    PubMed

    Ban, Li-Ping; Sun, Yin-Peng; Wang, Ying; Tu, Xiong-Bing; Zhang, Shan-Gan; Zhang, Yun-Ting; Wu, Yun-Sheng; Zhang, Ze-Hua

    2015-02-01

    The antennal sensilla of alate Myzus persicae were mapped using transmission electron microscopy and the ultrastructure of sensilla trichoidea, coeloconica, and placoidea are described. Trichoid sensilla, located on the tip of the antennae, are innervated by 2-4 neurons, with some outer dendrites reaching the distal end of the hair. Coeloconic sensilla in primary rhinaria are of two morphological types, both equipped with two dendrites. Dendrites of Type II coeloconic sensilla are enveloped in the dendrite sheath, containing the sensillum lymph. In sensilla coeloconica of Type I, instead, dendrites are enclosed by an electron opaque solid cuticle, with no space left for the sensillum lymph. The ultrastructure of big placoid sensillum reveals the presence of three groups of neurons, with 2-3 dendrites in each neuron group, while both small placoid sensilla are equipped with a single group of neurons, consisting of three dendrites. Both large and small placoid sensilla bear multiple pores on the outer cuticle. The function of these sensilla is also discussed. © 2014 Wiley Periodicals, Inc.

  19. Growth of wide-bandgap nitride semiconductors by MBE

    NASA Astrophysics Data System (ADS)

    Moustakas, T. D.

    2002-08-01

    This paper reviews progress in the heteroepitaxial growth of Ill-Nitride semiconductors. The growth of wurtzite and zinc-blende allotropic forms of GaN on various substrates with hexagonal and cubic symmetry respectively were discussed. In particular we addressed the growth on the various faces of sapphire, 6H-SiC and (001) Si. It has been shown that the kinetics of growth by plasma-MBE or ammonia-MBE are different. Specifically, in plasma-assisted MBE smooth films are obtained under group-III rich conditions of growth. On the other hand in ammonia-MBE smooth films are obtained under nitrogen rich conditions of growth. High quality films were obtained on 6H-SiC without the employment of any buffer. The various nucleation steps used to improve the two dimensional growth as well as to control the film polarity were discussed. The n- and p-doping of GaN were addressed. The concept of increasing the solubility of Mg in GaN by simultaneously bombarding the surface of the growing film with a flux of electrons (co-doping GaN with Mg and electrons) was discussed. The influence of the strength of Al-N, Ga-N and In-N bonds on the kinetics of growth of nitride alloys was pointed out. Specifically, it was shown that in both the nitrogen-rich and group-III rich growth regimes, the incorporation probability of aluminum is unity for the investigated temperature range of 750-800° C. On the other hand the incorporation probability of gallium is constant but less than unity only in the nitrogen-rich regime of growth. In the group-III regime the incorporation probability of gallium decreases monotonically with the total group-III flux, due to the competition with aluminum for the available active nitrogen. Alloy phenomena such as phase separation and atomic ordering and the influence of these phenomena to the optical properties were addressed. InGaN alloys are thermodynamically unstable against phase separation. At compositions above 30% they tend to undergo partial phase separation. Furthermore, InGaN alloys were found to undergo 1x1 monolayer cation ordering. AlGaN alloys do not show evidence of phase separation but they were found to undergo multiple type of superlattice ordering. Under nitrogen-rich growth conditions they show one monolayer periodicity, while under group-III rich growth it was found that the structure is a superposition of a seven monolayer and twelve monolayer superlattices. Finally, the growth of heterostructures and MQWs and the use of the MBE method for the fabrication of optical, electronic and electromechanical devices were discussed.

  20. MO-A-BRB-03: Integration Issues in Electronic Charting for External Beam Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sutlief, S.

    2015-06-15

    The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiationmore » therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy.« less

  1. MO-A-BRB-02: Considerations and Issues in Electronic Charting for Brachytherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Richardson, S.

    2015-06-15

    The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiationmore » therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy.« less

  2. Two new Neotropical species of Ceracis Mellié (Coleoptera, Ciidae) and redefinition of the cucullatus group

    PubMed Central

    Antunes-Carvalho, Caio; Lopes-Andrade, Cristiano

    2011-01-01

    Abstract Two new Neotropical species of Ceracis Mellié are described: Ceracis cassumbensis Antunes-Carvalho & Lopes-Andrade, sp. n. from a single locality in northeastern Brazil and Ceracis navarretei Antunes-Carvalho & Lopes-Andrade, sp. n. from a single locality in southern Mexico. Scanning Electron Microscope images of adults and photographs of holotypes and male terminalia are provided for both species, their similarities and differences with other Ceracis are briefly discussed, and the cucullatus species-group is redefined for including the new species described herein. PMID:22140333

  3. Congested ferrocenyl polyphosphanes bearing electron-donating or electron-withdrawing phosphanyl groups: assessment of metallocene conformation from NMR spin couplings and use in palladium-catalyzed chloroarenes activation.

    PubMed

    Mom, Sophal; Beaupérin, Matthieu; Roy, David; Royer, Sylviane; Amardeil, Régine; Cattey, Hélène; Doucet, Henri; Hierso, J-C

    2011-11-21

    The synthesis of novel substituted cyclopentadienyl salts that incorporate both a congested branched alkyl group (tert-butyl, (triphenyl)methyl, or tri(4-tert-butyl)phenylmethyl) and a phosphanyl group is reported. The introduction of either electron-withdrawing or electron-donating substituents (furyl, i-propyl, cyclohexyl, tert-butyl) on P atoms was generally achieved in high yield. The modular synthesis of ferrocenyl polyphosphanes from an assembly of these cyclopentadienyl salts was investigated, leading to the formation of new triphosphanes (denoted as 9-12) and diphosphanes (denoted as 14-16). The resulting phosphanes are not sensitive to air or moisture, even when electron-rich substituents are present. This set of polyphosphanes displays varied conformational features, which are discussed in the light of their multinuclear NMR characterization in solution and of the X-ray solid state structure of the representative triphosphane 1,2-bis(diphenylphosphanyl)-1'-(diisopropylphosphanyl)-3'-(triphenyl)methyl-4-tert-butyl ferrocene, 11. In particular, the existence of a range of significantly different nonbonded ("through-space", TS) spin-spin coupling constants between heteroannular P atoms, for the triphosphanes of this class, allowed their preferred conformation in solution to be appraised. The study evidences an unanticipated flexibility of the ferrocene platform, despite the presence of very congested tert-butyl and trityl groups. Herein, we show that, contrary to our first belief, the preferred conformation for the backbone of ferrocenyl polyphosphanes can not only depend on the hindrance of the groups decorating the cyclopentadienyl rings but is also a function of the substituents of the phosphanyl groups. The interest of these robust phosphanes as ligands was illustrated in palladium catalysis for the arylation of n-butyl furan with chloroarenes, using direct C-H activation of the heteroaromatic in the presence of low metal/ligand loadings (0.5-1.0 mol %). Thus, 4-chlorobenzonitrile, 4-chloronitrobenzene, 4-chloropropiophenone, and 4-(trifluoromethyl)chlorobenzene were efficiently coupled to n-butyl furan, using Pd(OAc)(2) associated to the new diphosphane ligands 1,1'-bis(diisopropylphosphanyl)-3,3'-di(triphenyl)methyl ferrocene (15) or 1,1'-bis(dicyclohexylphosphanyl)-3,3'-di(triphenyl)methylferrocene (16), which respectively hold the electron-rich -Pi-Pr(2) and -PCy(2) groups.

  4. Consumers' Preferences for Electronic Nicotine Delivery System Product Features: A Structured Content Analysis.

    PubMed

    Kistler, Christine E; Crutchfield, Trisha M; Sutfin, Erin L; Ranney, Leah M; Berman, Micah L; Zarkin, Gary A; Goldstein, Adam O

    2017-06-07

    To inform potential governmental regulations, we aimed to develop a list of electronic nicotine delivery system (ENDS) product features important to U.S. consumers by age and gender. We employed qualitative data methods. Participants were eligible if they had used an ENDS at least once. Groups were selected by age and gender (young adult group aged 18-25, n = 11; middle-age group aged 26-64, n = 9; and women's group aged 26-64, n = 9). We conducted five individual older adult interviews (aged 68-80). Participants discussed important ENDS features. We conducted a structured content analysis of the group and interview responses. Of 34 participants, 68% were white and 56% were female. Participants mentioned 12 important ENDS features, including: (1) user experience; (2) social acceptability; (3) cost; (4) health risks/benefits; (5) ease of use; (6) flavors; (7) smoking cessation aid; (8) nicotine content; (9) modifiability; (10) ENDS regulation; (11) bridge between tobacco cigarettes; (12) collectability. The most frequently mentioned ENDS feature was modifiability for young adults, user experience for middle-age and older adults, and flavor for the women's group. This study identified multiple features important to ENDS consumers. Groups differed in how they viewed various features by age and gender. These results can inform ongoing regulatory efforts.

  5. Consumers’ Preferences for Electronic Nicotine Delivery System Product Features: A Structured Content Analysis

    PubMed Central

    Kistler, Christine E.; Crutchfield, Trisha M.; Sutfin, Erin L.; Ranney, Leah M.; Berman, Micah L.; Zarkin, Gary A.; Goldstein, Adam O.

    2017-01-01

    To inform potential governmental regulations, we aimed to develop a list of electronic nicotine delivery system (ENDS) product features important to U.S. consumers by age and gender. We employed qualitative data methods. Participants were eligible if they had used an ENDS at least once. Groups were selected by age and gender (young adult group aged 18–25, n = 11; middle-age group aged 26–64, n = 9; and women’s group aged 26–64, n = 9). We conducted five individual older adult interviews (aged 68–80). Participants discussed important ENDS features. We conducted a structured content analysis of the group and interview responses. Of 34 participants, 68% were white and 56% were female. Participants mentioned 12 important ENDS features, including: (1) user experience; (2) social acceptability; (3) cost; (4) health risks/benefits; (5) ease of use; (6) flavors; (7) smoking cessation aid; (8) nicotine content; (9) modifiability; (10) ENDS regulation; (11) bridge between tobacco cigarettes; (12) collectability. The most frequently mentioned ENDS feature was modifiability for young adults, user experience for middle-age and older adults, and flavor for the women’s group. This study identified multiple features important to ENDS consumers. Groups differed in how they viewed various features by age and gender. These results can inform ongoing regulatory efforts. PMID:28590444

  6. Development of fluorescent probes based on protection-deprotection of the key functional groups for biological imaging.

    PubMed

    Tang, Yonghe; Lee, Dayoung; Wang, Jiaoliang; Li, Guanhan; Yu, Jinghua; Lin, Weiying; Yoon, Juyoung

    2015-08-07

    Recently, the strategy of protection-deprotection of functional groups has been widely employed to design fluorescent probes, as the protection-deprotection of functional groups often induces a marked change in electronic properties. Significant advances have been made in the development of analyte-responsive fluorescent probes based on the protection-deprotection strategy. In this tutorial review, we highlight the representative examples of small-molecule based fluorescent probes for bioimaging, which are operated via the protection-deprotection of key functional groups such as aldehyde, hydroxyl, and amino functional groups reported from 2010 to 2014. The discussion includes the general protection-deprotection methods for aldehyde, hydroxyl, or amino groups, as well as the design strategies, sensing mechanisms, and deprotection modes of the representative fluorescent imaging probes applied to bio-imaging.

  7. Patient and public views about the security and privacy of Electronic Health Records (EHRs) in the UK: results from a mixed methods study.

    PubMed

    Papoutsi, Chrysanthi; Reed, Julie E; Marston, Cicely; Lewis, Ruth; Majeed, Azeem; Bell, Derek

    2015-10-14

    Although policy discourses frame integrated Electronic Health Records (EHRs) as essential for contemporary healthcare systems, increased information sharing often raises concerns among patients and the public. This paper examines patient and public views about the security and privacy of EHRs used for health provision, research and policy in the UK. Sequential mixed methods study with a cross-sectional survey (in 2011) followed by focus group discussions (in 2012-2013). Survey participants (N = 5331) were recruited from primary and secondary care settings in West London (UK). Complete data for 2761 (51.8 %) participants were included in the final analysis for this paper. The survey results were discussed in 13 focus groups with people living with a range of different health conditions, and in 4 mixed focus groups with patients, health professionals and researchers (total N = 120). Qualitative data were analysed thematically. In the survey, 79 % of participants reported that they would worry about the security of their record if this was part of a national EHR system and 71 % thought the National Health Service (NHS) was unable to guarantee EHR safety at the time this work was carried out. Almost half (47 %) responded that EHRs would be less secure compared with the way their health record was held at the time of the survey. Of those who reported being worried about EHR security, many would nevertheless support their development (55 %), while 12 % would not support national EHRs and a sizeable proportion (33 %) were undecided. There were also variations by age, ethnicity and education. In focus group discussions participants weighed up perceived benefits against potential security and privacy threats from wider sharing of information, as well as discussing other perceived risks: commercial exploitation, lack of accountability, data inaccuracies, prejudice and inequalities in health provision. Patient and public worries about the security risks associated with integrated EHRs highlight the need for intensive public awareness and engagement initiatives, together with the establishment of trustworthy security and privacy mechanisms for health information sharing.

  8. Universality classes of order parameters composed of many-body bound states

    DOE PAGES

    Tsvelik, A. M.

    2016-11-28

    This theoretical paper discusses microscopic models giving rise to special types of order in which conduction electrons are bound together with localized spins to create composite order parameters. It is shown that composite order is related to the formation of a spin liquid with gapped excitations carrying quantum numbers which are a fraction of those of electron. These spin liquids are special in the sense that their formation necessarily involves spin degrees of freedom of both the conduction and the localized electrons and can be characterized by nonlocal order parameters. A detailed description of such spin liquid states is presentedmore » with a special care given to a demonstration of their robustness against local perturbations preserving the Lie group symmetry and the translational invariance.« less

  9. SUPERNOVAE, NEUTRON STARS, AND TWO KINDS OF NEUTRINO

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chiu, H.Y.

    1962-08-15

    The role of neutrinos in the core of a star that has undergone a supernova explosion is discussed. The existence of neutron stars, the Schwarzchild singularity in general relativity, and the meaning of conservation of baryons in the neighborhood of a Schwarzchild singularity are also considered. The problem of detection of neutron stars is discussed. It is concluded that neutron stars are the most plausible alternative for the remnant of the core of a supernova. The neutrino emission processes are divided into two groups: the neutrino associated with the meson (mu) and the production of electron neutrinos. (C.E.S.)

  10. Understanding PGM-free Catalysts by Linking Density Functional Theory Calculations and Structural Analysis: Perspectives and Challenges

    DOE PAGES

    Gonzales, Ivana; Artyushkova, Kateryna; Atanassov, Plamen

    2018-03-13

    Here, we discuss perspectives and challenges in applying density functional theory for the calculation of spectroscopic properties of platinum group metal (PGM)-free electrocatalysts for oxygen reduction. More specifically, we discuss recent advances in the density functional theory calculations of core-level shifts in binding energies of N 1s electrons as measured by X-ray photoelectron spectroscopy. The link between the density functional theory calculations, the electrocatalytic performance of the catalysts, and structural analysis using modern spectroscopic techniques is expected to significantly increase our understanding of PGM-free catalysts at the molecular level.

  11. Understanding PGM-free Catalysts by Linking Density Functional Theory Calculations and Structural Analysis: Perspectives and Challenges

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gonzales, Ivana; Artyushkova, Kateryna; Atanassov, Plamen

    Here, we discuss perspectives and challenges in applying density functional theory for the calculation of spectroscopic properties of platinum group metal (PGM)-free electrocatalysts for oxygen reduction. More specifically, we discuss recent advances in the density functional theory calculations of core-level shifts in binding energies of N 1s electrons as measured by X-ray photoelectron spectroscopy. The link between the density functional theory calculations, the electrocatalytic performance of the catalysts, and structural analysis using modern spectroscopic techniques is expected to significantly increase our understanding of PGM-free catalysts at the molecular level.

  12. Supercoherent states and physical systems

    NASA Technical Reports Server (NTRS)

    Fatyga, B. W.; Kostelecky, V. Alan; Nieto, Michael Martin; Truax, D. Rodney

    1992-01-01

    A method is developed for obtaining coherent states of a system admitting a supersymmetry. These states are called supercoherent states. The presented approach is based on an extension to supergroups of the usual group-theoretic approach. The example of the supersymmetric harmonic oscillator is discussed, thereby illustrating some of the attractive features of the method. Supercoherent states of an electron moving in a constant magnetic field are also described.

  13. Packaging and Embedded Electronics for the Next Generation

    NASA Technical Reports Server (NTRS)

    Sampson, Michael J.

    2010-01-01

    This viewgraph presentation describes examples of electronic packaging that protects an electronic element from handling, contamination, shock, vibration and light penetration. The use of Hermetic and non-hermetic packaging is also discussed. The topics include: 1) What is Electronic Packaging? 2) Why Package Electronic Parts? 3) Evolution of Packaging; 4) General Packaging Discussion; 5) Advanced non-hermetic packages; 6) Discussion of Hermeticity; 7) The Class Y Concept and Possible Extensions; 8) Embedded Technologies; and 9) NEPP Activities.

  14. Surface physics of semiconducting nanowires

    NASA Astrophysics Data System (ADS)

    Amato, Michele; Rurali, Riccardo

    2016-02-01

    Semiconducting nanowires (NWs) are firm candidates for novel nanoelectronic devices and a fruitful playground for fundamental physics. Ultra-thin nanowires, with diameters below 10 nm, present exotic quantum effects due to the confinement of the wave functions, e.g. widening of the electronic band-gap, deepening of the dopant states. However, although several reports of sub-10 nm wires exist to date, the most common NWs have diameters that range from 20 to 200 nm, where these quantum effects are absent or play a very minor role. Yet, the research activity on this field is very intense and these materials still promise to provide an important paradigm shift for the design of emerging electronic devices and different kinds of applications. A legitimate question is then: what makes a nanowire different from bulk systems? The answer is certainly the large surface-to-volume ratio. In this article we discuss the most salient features of surface physics and chemistry in group-IV semiconducting nanowires, focusing mostly on Si NWs. First we review the state-of-the-art of NW growth to achieve a smooth and controlled surface morphology. Next we discuss the importance of a proper surface passivation and its role on the NW electronic properties. Finally, stressing the importance of a large surface-to-volume ratio and emphasizing the fact that in a NW the surface is where most of the action takes place, we discuss molecular sensing and molecular doping.

  15. Study of the Chemical Space of Selected Bacteriostatic Sulfonamides from an Information Theory Point of View.

    PubMed

    López-Rosa, Sheila; Molina-Espíritu, Moyocoyani; Esquivel, Rodolfo O; Soriano-Correa, Catalina; Dehesa, Jésus S

    2016-12-05

    The relative structural location of a selected group of 27 sulfonamide-like molecules in a chemical space defined by three information theory quantities (Shannon entropy, Fisher information, and disequilibrium) is discussed. This group is composed of 15 active bacteriostatic molecules, 11 theoretically designed ones, and para-aminobenzoic acid. This endeavor allows molecules that share common chemical properties through the molecular backbone, but with significant differences in the identity of the chemical substituents, which might result in bacteriostatic activity, to be structurally classified and characterized. This is performed by quantifying the structural changes on the electron density distribution due to different functional groups and number of electrons. The macroscopic molecular features are described by means of the entropy-like notions of spatial electronic delocalization, order, and uniformity. Hence, an information theory three-dimensional space (IT-3D) emerges that allows molecules with common properties to be gathered. This space witnesses the biological activity of the sulfonamides. Some structural aspects and information theory properties can be associated, as a result of the IT-3D chemical space, with the bacteriostatic activity of these molecules. Most interesting is that the active bacteriostatic molecules are more similar to para-aminobenzoic acid than to the theoretically designed analogues. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Molecular symmetry group analysis of the low-wavenumber torsions and vibration-torsions in the S1 state and ground state cation of p-xylene: An investigation using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy

    NASA Astrophysics Data System (ADS)

    Gardner, Adrian M.; Tuttle, William D.; Groner, Peter; Wright, Timothy G.

    2017-03-01

    For the first time, a molecular symmetry group (MSG) analysis has been undertaken in the investigation of the electronic spectroscopy of p-xylene (p-dimethylbenzene). Torsional and vibration-torsional (vibtor) levels in the S1 state and ground state of the cation of p-xylene are investigated using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. In the present work, we concentrate on the 0-350 cm-1 region, where there are a number of torsional and vibtor bands and we discuss the assignment of this region. In Paper II [W. D. Tuttle et al., J. Chem. Phys. 146, 124309 (2017)], we examine the 350-600 cm-1 region where vibtor levels are observed as part of a Fermi resonance. The similarity of much of the observed spectral activity to that in the related substituted benzenes, toluene and para-fluorotoluene, is striking, despite the different symmetries. The discussion necessitates a consideration of the MSG of p-xylene, which has been designated G72, but we shall also designate [{3,3}]D2h and we include the symmetry operations, character table, and direct product table for this. We also discuss the symmetries of the internal rotor (torsional) levels and the selection rules for the particular electronic transition of p-xylene investigated here.

  17. Structural, vibrational, electronic investigations and quantum chemical studies of 2-amino-4-methoxybenzothiazole.

    PubMed

    Arjunan, V; Raj, Arushma; Santhanam, R; Marchewka, M K; Mohan, S

    2013-02-01

    Extensive vibrational investigations of 2-amino-4-methoxybenzothiazole have been carried out with FTIR and FT-Raman spectral techniques. The electronic structure of the molecule has been analysed by UV-Visible and NMR spectroscopies. The DFT studies were carried out with B3LYP and HF methods utilising 6-31G(d,p), 6-311++G(d,p) and cc-pVDZ basis sets to determine the structural, thermodynamical, vibrational, electronic characteristics of the compound and also to understand the electronic and steric influence of the methoxy amino groups on the skeletal frequencies. The mixing of the fundamental modes was determined with the help of total energy distribution (TED). The energies of the frontier molecular orbitals have also been determined. The kinetic and thermodynamic stability and chemical hardness of the molecule have been determined. Complete NBO analysis was also carried out to find out the intramolecular electronic interactions and their stabilisation energy. (1)H and (13)C NMR chemical shifts and the electronic transitions of the molecule are also discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Breaking resolution limits in ultrafast electron diffraction and microscopy.

    PubMed

    Baum, Peter; Zewail, Ahmed H

    2006-10-31

    Ultrafast electron microscopy and diffraction are powerful techniques for the study of the time-resolved structures of molecules, materials, and biological systems. Central to these approaches is the use of ultrafast coherent electron packets. The electron pulses typically have an energy of 30 keV for diffraction and 100-200 keV for microscopy, corresponding to speeds of 33-70% of the speed of light. Although the spatial resolution can reach the atomic scale, the temporal resolution is limited by the pulse width and by the difference in group velocities of electrons and the light used to initiate the dynamical change. In this contribution, we introduce the concept of tilted optical pulses into diffraction and imaging techniques and demonstrate the methodology experimentally. These advances allow us to reach limits of time resolution down to regimes of a few femtoseconds and, possibly, attoseconds. With tilted pulses, every part of the sample is excited at precisely the same time as when the electrons arrive at the specimen. Here, this approach is demonstrated for the most unfavorable case of ultrafast crystallography. We also present a method for measuring the duration of electron packets by autocorrelating electron pulses in free space and without streaking, and we discuss the potential of tilting the electron pulses themselves for applications in domains involving nuclear and electron motions.

  19. High-temperature mass spectrometry - Vaporization of group 4-B metal carbides. [using Knudsen effusion

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.

    1974-01-01

    The high temperature vaporization of the metal-carbon systems TiC, ZrC, HfC, and ThC was studied by the Knudsen effusion - mass spectrometric method. For each system the metal dicarbide and tetracarbide molecular species were identified in the gas phase. Relative ion currents of the carbides and metals were measured as a function of temperature. Second- and third-law methods were used to determine enthalpies. Maximum values were established for the dissociation energies of the metal monocarbide molecules TiC, ZrC, HfC, and ThC. Thermodynamic functions used in the calculations are discussed in terms of assumed molecular structures and electronic contributions to the partition functions. The trends shown by the dissociation energies of the carbides of Group 4B are compared with those of neighboring groups and discussed in relation to the corresponding oxides and chemical bonding. The high temperature molecular beam inlet system and double focusing mass spectrometer are described.

  20. Dynamics of 4-oxo-TEMPO-d16-15N nitroxide-propylene glycol system studied by ESR and ESE in liquid and glassy state in temperature range 10-295 K

    NASA Astrophysics Data System (ADS)

    Goslar, Janina; Hoffmann, Stanislaw K.; Lijewski, Stefan

    2016-08-01

    ESR spectra and electron spin relaxation of nitroxide radical in 4-oxo-TEMPO-d16-15N in propylene glycol were studied at X-band in the temperature range 10-295 K. The spin-lattice relaxation in the liquid viscous state determined from the resonance line shape is governed by three mechanisms occurring during isotropic molecular reorientations. In the glassy state below 200 K the spin-lattice relaxation, phase relaxation and electron spin echo envelope modulations (ESEEM) were studied by pulse spin echo technique using 2-pulse and 3-pulse induced signals. Electron spin-lattice relaxation is governed by a single non-phonon relaxation process produced by localized oscillators of energy 76 cm-1. Electron spin dephasing is dominated by a molecular motion producing a resonance-type peak in the temperature dependence of the dephasing rate around 120 K. The origin of the peak is discussed and a simple method for the peak shape analysis is proposed, which gives the activation energy of a thermally activated motion Ea = 7.8 kJ/mol and correlation time τ0 = 10-8 s. The spin echo amplitude is strongly modulated and FT spectrum contains a doublet of lines centered around the 2D nuclei Zeeman frequency. The splitting into the doublet is discussed as due to a weak hyperfine coupling of nitroxide unpaired electron with deuterium of reorienting CD3 groups.

  1. M-shell resolved high-resolution X-ray spectroscopic study of transient matter evolution driven by hot electrons in kJ-laser produced plasmas

    NASA Astrophysics Data System (ADS)

    Condamine, F. P.; Šmíd, M.; Renner, O.; Dozières, M.; Thais, F.; Angelo, P.; Rosmej, F. B.

    2017-03-01

    Hot electrons represent a key subject for high intensity laser produced plasmas and atomic physics. Simulations of the radiative properties indicate a high sensitivity to hot electrons, that in turn provides the possibility for their detailed characterization by high-resolution spectroscopic methods. Of particular interest is X-ray spectroscopy due to reduced photo-absorption in dense matter and their efficient generation by hot electrons (inner-shell ionization/excitation). Here, we report on an experimental campaign conducted at the ns, kJ laser facility PALS at Prague in Czech Republic. Thin copper foils have been irradiated with 1ω pulses. Two spherically bent quartz Bragg crystal spectrometers with high spectral (λ/Δλ > 5000) and spatial resolutions (Δx = 30µm) have been set up simultaneously to achieve a high level of confidence for the complex Kα emission group. In particular, this group, which shows a strong overlap between lines, can be resolved in several substructures. Furthermore, an emission on the red wing of the Kα2 transition (λ = 1.5444A) could be identified with Hartree-Fock atomic structure calculations. We discuss possible implications for the analysis of non-equilibrium phenomena and present first simulations.

  2. Maturing CCD Photon-Counting Technology for Space Flight

    NASA Technical Reports Server (NTRS)

    Mallik, Udayan; Lyon, Richard; Petrone, Peter; McElwain, Michael; Benford, Dominic; Clampin, Mark; Hicks, Brian

    2015-01-01

    This paper discusses charge blooming and starlight saturation - two potential technical problems - when using an Electron Multiplying Charge Coupled Device (EMCCD) type detector in a high-contrast instrument for imaging exoplanets. These problems especially affect an interferometric type coronagraph - coronagraphs that do not use a mask to physically block starlight in the science channel of the instrument. These problems are presented using images taken with a commercial Princeton Instrument EMCCD camera in the Goddard Space Flight Center's (GSFC), Interferometric Coronagraph facility. In addition, this paper discusses techniques to overcome such problems. This paper also discusses the development and architecture of a Field Programmable Gate Array and Digital-to-Analog Converter based shaped clock controller for a photon-counting EMCCD camera. The discussion contained here will inform high-contrast imaging groups in their work with EMCCD detectors.

  3. Mechanistic aspects of hydrogen abstraction for phenolic antioxidants. Electronic structure and topological electron density analysis.

    PubMed

    Singh, Nakul; O'Malley, Patrick J; Popelier, Paul L A

    2005-02-21

    Density functional calculations using the B3LYP functional are used to provide insight into the hydrogen abstraction mechanism of phenolic antioxidants. The energy profiles for 13 ortho, meta, para and di-methyl substituted phenols with hydroperoxyl radical have been determined. An excellent correlation between the enthalpy (DeltaH) and activation energy (DeltaEa) was found, obeying the Evans-Polanyi rule. The effects of hydrogen bonding on DeltaEa are also discussed. Electron donating groups at the ortho and para positions are able to lower the activation energy for hydrogen abstraction. The highly electron withdrawing fluoro substituent increases the activation energies relative to phenol at the meta position but not at the para position. The electron density is studied using the atoms in molecules (AIM) approach. Atomic and bond properties are extracted to describe the hydrogen atom abstraction mechanism. It is found that on going from reactants to transition state, the hydrogen atom experiences a loss in volume, electronic population and dipole moment. These features suggest that the phenol hydroperoxyl reactions proceed according to a proton coupled electron transfer (PCET) as opposed to a hydrogen atom transfer (HAT) mechanism.

  4. Communicating in organizations, part I: general principles of high-stakes discussions.

    PubMed

    Harolds, Jay A

    2012-03-01

    Communication skills are important for all members in an organization, and especially the leaders. Leaders must be proficient in many different types of conversations, such as one-on-one dialogue, group meetings, speeches, electronic exchanges of messages, newsletters, question and answer sessions with various stakeholders and the media, and so forth. This series of articles will review some important aspects of communication within an organization.

  5. LMS and New Media

    DTIC Science & Technology

    2009-08-19

    Management of Social Media The Caring Personal Agent SUSAN BULL1, JIM GREER2, GORD MCCALLA2 1 Educational Technology Research Group, Electronic...Discussion Forums, Leader Education , On Demand Learning . 24 Cianciolo, A. (2008) Study Report 2008-05. Program Evaluation for U.S. Army Lifelong...AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Advanced Decision Learning (ADL

  6. A novel base-induced isomerization gives access to unprecedented (E)-exo-glycals.

    PubMed

    Eppe, Guillaume; Dumitrescu, Lidia; Pierrot, Olivier; Li, Tianlei; Pan, Weidong; Vincent, Stéphane P

    2013-08-26

    Bump the base: This study reports the discovery of the base-induced Z-to-E isomerization of exo-glycals bearing an electron-withdrawing group (EWG). The scope of this novel transformation regarding the carbohydrate unit is also discussed. After elucidating the mechanism, preparation of novel (E)-exo- glycals was performed (TBS = tert-butyldimethylsilyl). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Syntheses, spectroscopic properties and molecular structure of silver phytate complexes - IR, UV-VIS studies and DFT calculations

    NASA Astrophysics Data System (ADS)

    Zając, A.; Dymińska, L.; Lorenc, J.; Ptak, M.; Hanuza, J.

    2018-03-01

    Silver phytate IP6, IP6Ag, IP6Ag2 and IP6Ag3 complexes in the solid state have been synthesized changing the phosphate to metal mole ratio. The obtained products have been characterized by means of chemical and spectroscopic studies. Attenuated total reflection Fourier transform infrared technique and Raman microscope were used in the measurements. These results were discussed in terms of DFT (Density Functional Theory) quantum chemical calculations using the B3LYP/6-31G(d,p) approach. The molecular structures of these compounds have been proposed on the basis of group theory and geometry optimization taking into account the shape and the number of the observed bands corresponding to the stretching and bending vibrations of the phosphate group and metal-oxygen polyhedron. The role of inter- and intra-hydrogen bonds in stabilization of the structure has been discussed. It was found that three types of hydrogen bonds appear in the studied compounds: terminal, and those engaged in the inter- and intra-molecular interactions. The Fermi resonance as a result of the strong intra-molecular Osbnd H⋯O hydrogen bonds was discovered. Electron absorption spectra have been measured to characterize the electron properties of the studied complexes and their local symmetry.

  8. Protonated o-semiquinone radical as a mimetic of the humic acids native radicals: A DFT approach to the molecular structure and EPR properties

    NASA Astrophysics Data System (ADS)

    Witwicki, Maciej; Jezierska, Julia

    2012-06-01

    Organic radicals are known to be an indispensable component of the humic acids (HA) structure. In HA two forms of radicals, stable (native) and short-lived (transient), are identified. Importantly, these radical forms can be easily differentiated by electron paramagnetic resonance (EPR) spectroscopy. This article provides a DFT-based insight into the electronic and molecular structure of the native radicals. The molecular models including an increase of the radical aromaticity and the hydrogen bonding between the radical and other functional groups of HA are taken under investigation. In consequence the interesting pieces of information on the structure of the native radical centers in HA are revealed and discussed, especially in terms of differences between the electronic structure of the native and transient forms.

  9. The work practice of medical secretaries and the implementation of electronic health records in Denmark.

    PubMed

    Bertelsen, Pernille; Nøhr, Christian

    The introduction of electronic health records will entail substantial organisational changes to the clinical and administrative staff in hospitals. Hospital owners in Denmark have predicted that these changes will render up to half of medical secretaries redundant. The present study however shows that medical secretaries have a great variety of duties, and often act as the organisational "glue" or connecting thread between other professional groups at the hospital. The aim of this study is to obtain a detailed understanding of the pluralism of work tasks the medical secretaries perform. It is concluded that clinicians as well as nurses depend on medical secretaries, and therefore to reduce the number of secretaries because electronic health record systems are implemented needs very careful thinking, planning and discussion with the other professions involved.

  10. Solar radio continuum storms

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Radio noise continuum emission observed in metric and decametric wave frequencies is discussed. The radio noise is associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. It is shown that the S-component emission in microwave frequencies generally occurs several days before the emission of the noise continuum storms of lower frequencies. It is likely that energetic electrons, 10 to 100 Kev, accelerated in association with the variation of sunspot magnetic fields, are the sources of the radio emissions. A model is considered to explain the relation of burst storms on radio noise. An analysis of the role of energetic electrons on the emissions of both noise continuum and type III burst storms is presented. It is shown that instabilities associated with the electrons and their relation to their own stabilizing effects are important in interpreting both of these storms.

  11. Electron self-injection in the donut bubble wakefield

    NASA Astrophysics Data System (ADS)

    Firouzjaei, Ali Shekari; Shokri, Babak

    2018-05-01

    We investigate electron self-injection in a donut bubble wakefield driven by a Laguerre-Gauss laser pulse. The present work discusses the electron capture by modeling the analytical donut bubble field. We discuss the self-injection of the electrons from plasma for various initial conditions and then compare the results. We show that the donut bubble can trap plasma electrons forming a hollow beam. We present the phase spaces and longitudinal momentum evolution for the trapped electrons in the bubble and discuss their characteristic behaviors and stability. It will be shown that the electrons self-injected in the front are ideal for applications in which a good stability and low energy spread are essential.

  12. Valence State Driven Site Preference in the Quaternary Compound Ca5MgAgGe5: An Electron-Deficient Phase with Optimized Bonding

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ponou, Simeon; Lidin, Sven; Zhang, Yuemei

    The quaternary phase Ca5Mg0.95Ag1.05(1)Ge5 (3) was synthesized by high-temperature solid-state techniques, and its crystal structure was determined by single-crystal diffraction methods in the orthorhombic space group Pnma – Wyckoff sequence c12 with a = 23.1481(4) Å, b = 4.4736(1) Å, c = 11.0128(2) Å, V = 1140.43(4) Å3, Z = 4. The crystal structure can be described as linear intergrowths of slabs cut from the CaGe (CrB-type) and the CaMGe (TiNiSi-type; M = Mg, Ag) structures. Hence, 3 is a hettotype of the hitherto missing n = 3 member of the structure series with the general formula R2+nT2X2+n, previously describedmore » with n = 1, 2, and 4. The member with n = 3 was predicted in the space group Cmcm – Wyckoff sequence f5c2. The experimental space group Pnma (in the nonstandard setting Pmcn) corresponds to a klassengleiche symmetry reduction of index two of the predicted space group Cmcm. This transition originates from the switching of one Ge and one Ag position in the TiNiSi-related slab, a process that triggers an uncoupling of each of the five 8f sites in Cmcm into two 4c sites in Pnma. The Mg/Ag site preference was investigated using VASP calculations and revealed a remarkable example of an intermetallic compound for which the electrostatic valency principle is a critical structure-directing force. The compound is deficient by one valence electron according to the Zintl concept, but LMTO electronic structure calculations indicate electronic stabilization and overall bonding optimization in the polyanionic network. Other stability factors beyond the Zintl concept that may account for the electronic stabilization are discussed.« less

  13. Spectral, coordination and thermal properties of 5-arylidene thiobarbituric acids

    NASA Astrophysics Data System (ADS)

    Masoud, Mamdouh S.; El-Marghany, Adel; Orabi, Adel; Ali, Alaa E.; Sayed, Reham

    2013-04-01

    Synthesis of 5-arylidine thiobarbituric acids containing different functional groups with variable electronic characters were described and their Co2+, Ni2+ and Cu2+ complexes. The stereochemistry and mode of bonding of 5-(substituted benzylidine)-2-TBA complexes were achieved based on elemental analysis, spectral (UV-VIS, IR, 1H NMR, MS), magnetic susceptibility and conductivity measurements. The ligands were of bidentate and tridentate bonding through S, N and O of pyrimidine nucleolus. All complexes were of octahedral configuration. The thermal data of the complexes pointed to their stability. The mechanism of the thermal decomposition is discussed. The thermodynamic parameters of the dissociation steps were evaluated and discussed.

  14. The structure of 110 tilt boundaries in large area solar silicon

    NASA Technical Reports Server (NTRS)

    Ast, D. G.; Cunningham, B.; Vaudin, M.

    1982-01-01

    The models of Hornstra and their connection to the repeating group description of grain boundaries (7-10) are discussed. A model for the Sigma = 27 boundary containing a zig-zag arrangement of dislocations is constructed and it is shown that zig-zag models can account for the contrast features observed in high resolution transmission electron micrographs of second and third order twin boundaries in silicon. The boundaries discussed are symmetric with a 110 tilt axis and a (110) boundary plane in the median lattice (the median plane). The median lattice is identical in structure and halfway in orientation between the crystal lattices either side of the boundary.

  15. Software engineering risk factors in the implementation of a small electronic medical record system: the problem of scalability.

    PubMed

    Chiang, Michael F; Starren, Justin B

    2002-01-01

    The successful implementation of clinical information systems is difficult. In examining the reasons and potential solutions for this problem, the medical informatics community may benefit from the lessons of a rich body of software engineering and management literature about the failure of software projects. Based on previous studies, we present a conceptual framework for understanding the risk factors associated with large-scale projects. However, the vast majority of existing literature is based on large, enterprise-wide systems, and it unclear whether those results may be scaled down and applied to smaller projects such as departmental medical information systems. To examine this issue, we discuss the case study of a delayed electronic medical record implementation project in a small specialty practice at Columbia-Presbyterian Medical Center. While the factors contributing to the delay of this small project share some attributes with those found in larger organizations, there are important differences. The significance of these differences for groups implementing small medical information systems is discussed.

  16. Molecular anions.

    PubMed

    Simons, Jack

    2008-07-24

    The experimental and theoretical study of molecular anions has undergone explosive growth over the past 40 years. Advances in techniques used to generate anions in appreciable numbers as well as new ion-storage, ion-optics, and laser spectroscopic tools have been key on the experimental front. Theoretical developments on the electronic structure and molecular dynamics fronts now allow one to achieve higher accuracy and to study electronically metastable states, thus bringing theory in close collaboration with experiment in this field. In this article, many of the experimental and theoretical challenges specific to studying molecular anions are discussed. Results from many research groups on several classes of molecular anions are overviewed, and both literature citations and active (in online html and pdf versions) links to numerous contributing scientists' Web sites are provided. Specific focus is made on the following families of anions: dipole-bound, zwitterion-bound, double-Rydberg, multiply charged, metastable, cluster-based, and biological anions. In discussing each kind of anion, emphasis is placed on the structural, energetic, spectroscopic, and chemical-reactivity characteristics that make these anions novel, interesting, and important.

  17. Flexible Organic Electronics in Biology: Materials and Devices.

    PubMed

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-09

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Molecular structures and intramolecular dynamics of pentahalides

    NASA Astrophysics Data System (ADS)

    Ischenko, A. A.

    2017-03-01

    This paper reviews advances of modern gas electron diffraction (GED) method combined with high-resolution spectroscopy and quantum chemical calculations in studies of the impact of intramolecular dynamics in free molecules of pentahalides. Some recently developed approaches to the electron diffraction data interpretation, based on direct incorporation of the adiabatic potential energy surface parameters to the diffraction intensity are described. In this way, complementary data of different experimental and computational methods can be directly combined for solving problems of the molecular structure and its dynamics. The possibility to evaluate some important parameters of the adiabatic potential energy surface - barriers to pseudorotation and saddle point of intermediate configuration from diffraction intensities in solving the inverse GED problem is demonstrated on several examples. With increasing accuracy of the electron diffraction intensities and the development of the theoretical background of electron scattering and data interpretation, it has become possible to investigate complex nuclear dynamics in fluxional systems by the GED method. Results of other research groups are also included in the discussion.

  19. Electron cyclotron thruster new modeling results preparation for initial experiments

    NASA Technical Reports Server (NTRS)

    Hooper, E. Bickford

    1993-01-01

    The following topics are discussed: a whistler-based electron cyclotron resonance heating (ECRH) thruster; cross-field coupling in the helicon approximation; wave propagation; wave structure; plasma density; wave absorption; the electron distribution function; isothermal and adiabatic plasma flow; ECRH thruster modeling; a PIC code model; electron temperature; electron energy; and initial experimental tests. The discussion is presented in vugraph form.

  20. Ultrafast electronic dynamics driven by nuclear motion

    NASA Astrophysics Data System (ADS)

    Vendrell, Oriol

    2016-05-01

    The transfer of electrical charge on a microscopic scale plays a fundamental role in chemistry, in biology, and in technological applications. In this contribution, we will discuss situations in which nuclear motion plays a central role in driving the electronic dynamics of photo-excited or photo-ionized molecular systems. In particular, we will explore theoretically the ultrafast transfer of a double electron hole between the functional groups of glycine after K-shell ionization and subsequent Auger decay. Although a large energy gap of about 15 eV initially exists between the two electronic states involved and coherent electronic dynamics play no role in the hole transfer, we will illustrate how the double hole can be transferred within 3 to 4 fs between both functional ends of the glycine molecule driven solely by specific nuclear displacements and non-Born-Oppenheimer effects. This finding challenges the common wisdom that nuclear dynamics of the molecular skeleton are unimportant for charge transfer processes at the few-femtosecond time scale and shows that they can even play a prominent role. We thank the Hamburg Centre for Ultrafast Imaging and the Volkswagen Foundation for financial support.

  1. Teaching Students to Correspond Effectively Electronically.

    ERIC Educational Resources Information Center

    Extejt, Marian M.

    1998-01-01

    Discusses current standards for formatting and etiquette of electronic mail in the business setting. Discusses privacy and appropriate content. Notes that class assignments involving electronic mail provide practical opportunities to develop ease with this form. (SR)

  2. Abductive networks applied to electronic combat

    NASA Astrophysics Data System (ADS)

    Montgomery, Gerard J.; Hess, Paul; Hwang, Jong S.

    1990-08-01

    A practical approach to dealing with combinatorial decision problems and uncertainties associated with electronic combat through the use of networks of high-level functional elements called abductive networks is presented. It describes the application of the Abductory Induction Mechanism (AIMTM) a supervised inductive learning tool for synthesizing polynomial abductive networks to the electronic combat problem domain. From databases of historical expert-generated or simulated combat engagements AIM can often induce compact and robust network models for making effective real-time electronic combat decisions despite significant uncertainties or a combinatorial explosion of possible situations. The feasibility of applying abductive networks to realize advanced combat decision aiding capabilities was demonstrated by applying AIM to a set of electronic combat simulations. The networks synthesized by AIM generated accurate assessments of the intent lethality and overall risk associated with a variety of simulated threats and produced reasonable estimates of the expected effectiveness of a group of electronic countermeasures for a large number of simulated combat scenarios. This paper presents the application of abductive networks to electronic combat summarizes the results of experiments performed using AIM discusses the benefits and limitations of applying abductive networks to electronic combat and indicates why abductive networks can often result in capabilities not attainable using alternative approaches. 1. ELECTRONIC COMBAT. UNCERTAINTY. AND MACHINE LEARNING Electronic combat has become an essential part of the ability to make war and has become increasingly complex since

  3. Breaking resolution limits in ultrafast electron diffraction and microscopy

    PubMed Central

    Baum, Peter; Zewail, Ahmed H.

    2006-01-01

    Ultrafast electron microscopy and diffraction are powerful techniques for the study of the time-resolved structures of molecules, materials, and biological systems. Central to these approaches is the use of ultrafast coherent electron packets. The electron pulses typically have an energy of 30 keV for diffraction and 100–200 keV for microscopy, corresponding to speeds of 33–70% of the speed of light. Although the spatial resolution can reach the atomic scale, the temporal resolution is limited by the pulse width and by the difference in group velocities of electrons and the light used to initiate the dynamical change. In this contribution, we introduce the concept of tilted optical pulses into diffraction and imaging techniques and demonstrate the methodology experimentally. These advances allow us to reach limits of time resolution down to regimes of a few femtoseconds and, possibly, attoseconds. With tilted pulses, every part of the sample is excited at precisely the same time as when the electrons arrive at the specimen. Here, this approach is demonstrated for the most unfavorable case of ultrafast crystallography. We also present a method for measuring the duration of electron packets by autocorrelating electron pulses in free space and without streaking, and we discuss the potential of tilting the electron pulses themselves for applications in domains involving nuclear and electron motions. PMID:17056711

  4. Direct modeling of the electrochemistry in the three-phase boundary of solid oxide fuel cell anodes by density functional theory: a critical overview.

    PubMed

    Shishkin, M; Ziegler, T

    2014-02-07

    The first principles modeling of electrochemical reactions has proven useful for the development of efficient, durable and low cost solid oxide full cells (SOFCs). In this account we focus on recent advances in modeling of structural, electronic and catalytic properties of the SOFC anodes based on density functional theory (DFT) first principle calculations. As a starting point, we highlight that the adequate analysis of cell electrochemistry generally requires modeling of chemical reactions at the metal/oxide interface rather than on individual metal or oxide surfaces. The atomic models of Ni/YSZ and Ni/CeO2 interfaces, required for DFT simulations of reactions on SOFC anodes are discussed next, together with the analysis of the electronic structure of these interfaces. Then we proceed to DFT-based findings on charge transfer mechanisms during redox reactions on these two anodes. We provide a comparison of the electronic properties of Ni/YSZ and Ni/CeO2 interfaces and present an interpretation of their different chemical performances. Subsequently we discuss the computed energy pathways of fuel oxidation mechanisms, obtained by various groups to date. We also discuss the results of DFT studies combined with microkinetic modeling as well as the results of kinetic Monte Carlo simulations. In conclusion we summarize the key findings of DFT modeling of metal/oxide interfaces to date and highlight possible directions in the future modeling of SOFC anodes.

  5. Survey of Computer-Based Message Systems; COM/PortaCOM Conference System: Design Goals and Principles; Computer Conferencing Is More Than Electronic Mail; Effects of the COM Computer Conference System.

    ERIC Educational Resources Information Center

    Palme, Jacob

    The four papers contained in this document provide: (1) a survey of computer based mail and conference systems; (2) an evaluation of systems for both individually addressed mail and group addressing through conferences and distribution lists; (3) a discussion of various methods of structuring the text data in existing systems; and (4) a…

  6. Cyberwar to Wikiwar: Battles for Cyberspace

    DTIC Science & Technology

    2013-01-01

    book, Cypherpunks : Freedom and the Future of Internet, this belief comes into sharp focus. The book takes its name from the cypher- punks movement...intrusive state surveillance. The book is a compila- tion of discussions of fellow believers in the cypherpunks ’ slogan of “privacy for the weak...especially in the case of the Syrian Electronic Army. It is unclear whether the group of cypherpunks would approve of another hacktivist group’s online

  7. Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials

    NASA Astrophysics Data System (ADS)

    Callewaert, Vincent; Saniz, Rolando; Barbiellini, Bernardo; Bansil, Arun; Partoens, Bart

    2017-08-01

    We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes.

  8. An Application of the Direct Coulomb Electron Pair Production Process to the Energy Measurement of the "VH-Group" in the "Knee" Region of the "All-Particle" Energy Spectrum

    NASA Technical Reports Server (NTRS)

    Derrickson, J. H.; Wu, J.; Christl, M. J.; Fountain, W. F.; Parnell, T. A.

    1999-01-01

    The "all-particle" cosmic ray energy spectrum appears to be exhibiting a significant change in the spectral index just above approximately 3000 TeV. This could indicate (1) a change in the propagation of the cosmic rays in the galactic medium, and/or (2) the upper limit of the supernova shock wave acceleration mechanism, and/or (3) a new source of high-energy cosmic rays. Air shower and JACEE data indicate the spectral change is associated with a composition change to a heavier element mixture whereas DICE does not indicate this. A detector concept will be presented that utilizes the energy dependence of the production of direct Coulomb electron-positron pairs by energetic heavy ions. Monte Carlo simulations of a direct electron pair detector consisting of Pb target foils interleaved with planes of 1-mm square scintillating optical fibers will be discussed. The goal is to design a large area, non-saturating instrument to measure the energy spectrum of the individual cosmic ray elements in the "VH-group" for energies greater than 10 TeV/nucleon.

  9. Effect of Molecular Rotation on Charge Transport Phenomena

    NASA Astrophysics Data System (ADS)

    Garg, O. P.; Lamba, Vijay Kr; Kaushik, D. K.

    2015-12-01

    The study of electron transport properties of molecular systems could be explained on the basis of the Landauer formalism. Unfortunately, due to the complexity of the experimental setup, most of these measurements have no control over the details of the electrode geometry, rotation of molecules, variation in angle of contacts, effect of fano resonances associated with side groups attached to rigid backbones, which results in a spectrum of IV-characteristics. Theoretical models can therefore help to understand and helps to develop new applications such as molecular sensors, etc. Thus we used simulation methods that generate the required structural ensemble, which is then analyzed with Green’s function methods to characterize the electronic transport properties. In present work we had discussed applications of this approach to understand the conductance in molecular system in the direction of controlling electron transport through molecules and studied the effect of rotation of sandwiched molecule.

  10. A rhenium complex doped in a silica molecular sieve for molecular oxygen sensing: Construction and characterization.

    PubMed

    Yang, Xiaozhou; Li, Yanxiao

    2016-01-15

    This paper reported a diamine ligand and its Re(I) complex for potential application in oxygen sensing. The novelty of this diamine ligand localized at its increased conjugation chain which had a typical electron-withdrawing group of 1,3,4-oxadiazole. Electronic distribution of excited electrons and their lifetime were supposed to be increased, favoring oxygen sensing collision. This hypothesis was confirmed by single crystal analysis, theoretical calculation and photophysical measurement. It was found that this Re(I) complex had a long-lived emission peaking at 545 nm, favoring sensing application. By doping this complex into a silica matrix MCM-41, oxygen sensing performance and mechanism of the resulting composites were discussed in detail. Non-linear Stern-Volmer working curves were observed with maximum sensitivity of 5.54 and short response time of ~6 s. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Enhancing Student Empathetic Engagement, History-Taking, and Communication Skills During Electronic Medical Record Use in Patient Care.

    PubMed

    LoSasso, Alisa Alfonsi; Lamberton, Courtney E; Sammon, Mary; Berg, Katherine T; Caruso, John W; Cass, Jonathan; Hojat, Mohammadreza

    2017-07-01

    To examine whether an intervention on proper use of electronic medical records (EMRs) in patient care could help improve medical students' empathic engagement, and to test the hypothesis that the training would reduce communication hurdles in clinical encounters. Seventy third-year medical students from the Sidney Kimmel Medical College at Thomas Jefferson University were randomly divided into intervention and control groups during their six-week pediatric clerkship in 2012-2013. The intervention group received a one-hour training session on EMR-specific communication skills, including discussion of EMR use, the SALTED mnemonic and technique (Set-up, Ask, Listen, Type, Exceptions, Documentation), and role-plays. Both groups completed the Jefferson Scale of Empathy (JSE) at the clerkship's start and end. At clerkship's end, faculty and standardized patients (SPs) rated students' empathic engagement in SP encounters, using the Jefferson Scale of Patient Perceptions of Physician Empathy (JSPPPE), and their history-taking and communication skills. Faculty mean ratings on the JSPPPE, history-taking skills, and communication skills were significantly higher for the intervention group than the control group. SP mean ratings on history-taking skills were significantly higher for the intervention group than the control group. Both groups' JSE mean scores increased pretest to posttest, but the changes were not significant. The intervention group's posttest JSE mean score was higher than the control group's, but the difference was not significant. The findings suggest that a simple intervention providing specialized training in EMR-specific communication can improve medical students' empathic engagement in patient care, history-taking skills, and communication skills.

  12. Theoretical study of the hydrogen abstraction of substituted phenols by nitrogen dioxide as a source of HONO.

    PubMed

    Shenghur, Abraham; Weber, Kevin H; Nguyen, Nhan D; Sontising, Watit; Tao, Fu-Ming

    2014-11-20

    The mild yet promiscuous reactions of nitrogen dioxide (NO2) and phenolic derivatives to produce nitrous acid (HONO) have been explored with density functional theory calculations. The reaction is found to occur via four distinct pathways with both proton coupled electron transfer (PCET) and hydrogen atom transfer (HAT) mechanisms available. While the parent reaction with phenol may not be significant in the gas phase, electron donating groups in the ortho and para positions facilitate the reduction of nitrogen dioxide by electronically stabilizing the product phenoxy radical. Hydrogen bonding groups in the ortho position may additionally stabilize the nascent resonantly stabilized radical product, thus enhancing the reaction. Catechol (ortho-hydroxy phenol) has a predicted overall free energy change ΔG(0) = -0.8 kcal mol(-1) and electronic activation energy Ea = 7.0 kcal mol(-1). Free amines at the ortho and para positions have ΔG(0) = -3.8 and -1.5 kcal mol(-1); Ea = 2.3 and 2.1 kcal mol(-1), respectively. The results indicate that the hydrogen abstraction reactions of these substituted phenols by NO2 are fast and spontaneous. Hammett constants produce a linear correlation with bond dissociation energy (BDE) demonstrating that the BDE is the main parameter controlling the dark abstraction reaction. The implications for atmospheric chemistry and ground-level nitrous acid production are discussed.

  13. Acenes, Heteroacenes and Analogous Molecules for Organic Photovoltaic and Field Effect Transistor Applications

    NASA Astrophysics Data System (ADS)

    Granger, Devin Benjamin

    Polycyclic aromatic hydrocarbons composed of benzenoid rings fused in a linear fashion comprise the class of compounds known as acenes. The structures containing three to six ring fusions are brightly colored and possess band gaps and charge transport efficiencies sufficient for semiconductor applications. These molecules have been investigated throughout the past several decades to assess their optoelectronic properties. The absorption, emission and charge transport properties of this series of molecules has been studied extensively to elucidate structure-property relationships. A wide variety of analogous molecules, incorporating heterocycles in place of benzenoid rings, demonstrate similar properties to the parent compounds and have likewise been investigated. Functionalization of acene compounds by placement of groups around the molecule affects the way in which molecules interact in the solid state, in addition to the energetics of the molecule. The use of electron donating or electron withdrawing groups affects the frontier molecular orbitals and thus affects the optical and electronic gaps of the molecules. The use of bulky side groups such as alkylsilylethynyl groups allows for crystal engineering of molecular aggregates, and changing the volume and dimensions of the alkylsilyl groups affects the intermolecular interactions and thus changes the packing motif. In chapter 2, a series of tetracene and pentacene molecules with strongly electron withdrawing groups is described. The investigation focuses on the change in energetics of the frontier molecular orbitals between the base acene and the nitrile and dicyanovinyl derivatives as well as the differences between the pentacene and tetracene molecules. The differences in close packing motifs through use of bulky alkylsilylethynyl groups is also discussed in relation to electron acceptor material design and bulk heterojunction organic photovoltaic characteristics. Chapter 3 focuses on molecular acceptor and donor molecules for bulk heterojunction organic photovoltaics based on anthrathiophene and benzo[1,2-b:4,5-b']dithiophene central units like literature molecules containing fluorene and dithieno[2,3-b:2',3'-d]silole cores. The synthetic strategies of developing reduced symmetry benzo[1,2-b:4,5-b']dithiophene to study the effect of substitution around the central unit is also described. The optical and electronic properties of the donors and acceptors are described along with the performance and characteristics of devices employing these molecules. The final two data chapters focus on new nitrogen containing polycyclic hydrocarbons containing indolizine and (2.2.2) cyclazine units. The optical, electronic and other physical properties of these molecules are explored, in addition to the synthetic strategies for incorporating the indolizine and cyclazine units. By use of alkylsilylethynyl groups, crystal engineering was investigated for the benzo[2,3-b:5,6-b']diindolizine chromophore described in chapter 4 to target the 2-D "brick-work" packing motif for application in field effect transistor devices. Optical and electronic properties of the cyclazine end-capped acene molecules described in chapter 5 were investigated and described in relation to the base acene molecules. In both cases, density functional theory calculations were conducted to better understand unexpected optical properties of these molecules, which are like the linear acene series despite the non-linear attachment.

  14. Use of personal phones by senior nursing students to access health care information during clinical education: staff nurses' and students' perceptions.

    PubMed

    Wittmann-Price, Ruth A; Kennedy, Lynn D; Godwin, Catherine

    2012-11-01

    Research indicates that having electronic resources readily available increases learners' ability to make clinical decisions and confidence in patient care. This mixed-method, descriptive pilot study collected data about senior prelicensure nursing students using smartphones, a type of mobile electronic device (MED), in the clinical area. The smartphones contained nursing diagnosis, pharmacology, and laboratory information; an encyclopedia; and the MEDLINE database. Student (n = 7) data about smartphone use during a 10-week clinical rotation were collected via student-recorded usage logs and focus group recordings. Staff nurses' (n = 5) perceptions of students' use of smartphones for clinical educational resources were collected by anonymous survey. Both the focus group transcript and staff surveys were evaluated and the themes summarized by content analysis. Positive results and barriers to use, such as cost and technological comfort levels, are discussed. The results may help nurse educators and administrators initiate further research of MEDs as a clinical resource. Copyright 2012, SLACK Incorporated.

  15. A Diffusion Model for Two-sided Service Systems

    NASA Astrophysics Data System (ADS)

    Homma, Koichi; Yano, Koujin; Funabashi, Motohisa

    A diffusion model is proposed for two-sided service systems. ‘Two-sided’ refers to the existence of an economic network effect between two different and interrelated groups, e.g., card holders and merchants in an electronic money service. The service benefit for a member of one side depends on the number and quality of the members on the other side. A mathematical model by J. H. Rohlfs explains the network (or bandwagon) effect of communications services. In Rohlfs' model, only the users' group exists and the model is one-sided. This paper extends Rohlfs' model to a two-sided model. We propose, first, a micro model that explains individual behavior in regard to service subscription of both sides and a computational method that drives the proposed model. Second, we develop macro models with two diffusion-rate variables by simplifying the micro model. As a case study, we apply the models to an electronic money service and discuss the simulation results and actual statistics.

  16. Bosnian and American students' attitudes toward electronic monitoring: is it about what we know or where we come from?

    PubMed

    Muftić, Lisa R; Payne, Brian K; Maljević, Almir

    2015-06-01

    The use of community corrections continues to grow across the globe as alternatives to incarceration are sought. Little research attention, however, has been directed at correctional alternatives from a global orientation. The purpose of this research study is to compare the way that a sample of criminal justice students from the United States (n = 118) and Bosnia and Herzegovina (n = 133) perceive electronic monitoring. Because electronic monitoring is a newer sentencing alternative and it is used differently in Bosnia and Herzegovina than it is in the United States, it is predicted that Bosnian students will view electronic monitoring differently than will students from the United States. This study finds that while students are largely supportive of electronic monitoring sentences, support is affected by offender type and student nationality. For example, Bosnian students are more supportive of electronic monitoring sentences for drug offenders while American students are more supportive of electronic monitoring sentences for juvenile offenders. Differences were also found across student groups when attitudes toward electronic monitoring and the costs and pains associated with electronic monitoring were assessed. Specifically, American students were less likely to view electronic monitoring as meeting the goals of rehabilitation and more likely to view the conditions and restrictions associated with electronic monitoring as being punitive than Bosnian students were. Implications from these findings, as well as limitations and suggestions for further research are discussed. © The Author(s) 2013.

  17. Modulated Electron Emission by Scattering-Interference of Primary Electrons

    NASA Astrophysics Data System (ADS)

    Valeri, Sergio; di Bona, Alessandro

    We review the effects of scattering-interference of the primary, exciting beam on the electron emission from ordered atomic arrays. The yield of elastically and inelastically backscattered electrons, Auger electrons and secondary electrons shows a marked dependence on the incidence angle of primary electrons. Both the similarity and the relative importance of processes experienced by incident and excident electrons are discussed. We also present recent studies of electron focusing and defocusing along atomic chains. The interplay between these two processes determines the in-depth profile of the primary electron intensity anisotropy. Finally, the potential for surface-structural studies and limits for quantitative analysis are discussed, in comparison with the Auger electron diffraction (AED) and photoelectron diffraction (PD) techniques.

  18. Electronic and optical properties of strained graphene and other strained 2D materials: a review.

    PubMed

    Naumis, Gerardo G; Barraza-Lopez, Salvador; Oliva-Leyva, Maurice; Terrones, Humberto

    2017-09-01

    This review presents the state of the art in strain and ripple-induced effects on the electronic and optical properties of graphene. It starts by providing the crystallographic description of mechanical deformations, as well as the diffraction pattern for different kinds of representative deformation fields. Then, the focus turns to the unique elastic properties of graphene, and to how strain is produced. Thereafter, various theoretical approaches used to study the electronic properties of strained graphene are examined, discussing the advantages of each. These approaches provide a platform to describe exotic properties, such as a fractal spectrum related with quasicrystals, a mixed Dirac-Schrödinger behavior, emergent gravity, topological insulator states, in molecular graphene and other 2D discrete lattices. The physical consequences of strain on the optical properties are reviewed next, with a focus on the Raman spectrum. At the same time, recent advances to tune the optical conductivity of graphene by strain engineering are given, which open new paths in device applications. Finally, a brief review of strain effects in multilayered graphene and other promising 2D materials like silicene and materials based on other group-IV elements, phosphorene, dichalcogenide- and monochalcogenide-monolayers is presented, with a brief discussion of interplays among strain, thermal effects, and illumination in the latter material family.

  19. Interaction and Correlation Effects in Quasi Two-dimensional Materials

    NASA Astrophysics Data System (ADS)

    Louie, Steven G.

    2015-03-01

    Experimental and theoretical studies of atomically thin quasi two-dimensional materials (typically related to some parent van der Waals layered crystals) and their nanostructures have revealed that these systems can exhibit highly unusual behaviors. In this talk, we discuss some theoretical studies of the electronic, transport and optical properties of such systems. We present results on graphene and graphene nanostructures as well as other quasi-2D systems such as monolayer and few-layer transition metal dichalcogenides (e.g., MoS2, MoSe2, WS2, and WSe2) and metal monochalcogenides (such as GaSe and FeSe). Owing to their reduced dimensionality, these systems present opportunities for unusual manifestation of concepts and phenomena that may not be so prominent or have not been seen in bulk materials. Symmetry and many-body interaction effects often play a critical role in shaping qualitatively and quantitatively their properties. Several quantum phenomena are discussed, including novel and dominant exciton effects, tunable magnetism, electron supercollimation by disorder, unusual plasmon behaviors, and possible enhanced superconductivity in some of these systems. We investigate their physical origins and compare theoretical predictions with experimental data. This work was supported by DOE under Contract No. DE-AC02-05CH11231 and by NSF under Grant No. DMR10-1006184. I would like to acknowledge collaborations with members of the Louie group and the experimental groups of Crommie, Heinz, Wang, and Zhang.

  20. Structure of transition-metal cluster compounds: Use of an additional orbital resulting from the f, g character of spd bond orbitals*

    PubMed Central

    Pauling, Linus

    1977-01-01

    A general theory of the structure of complexes of the transition metals is developed on the basis of the enneacovalence of the metals and the requirements of the electroneutrality principle. An extra orbital may be provided through the small but not negligible amount of f and g character of spd bond orbitals, and an extra electron or electron pair may be accepted in this orbital for a single metal or a cluster to neutralize the positive electric charge resulting from the partial ionic character of the bonds with ligands, such as the carbonyl group. Examples of cluster compounds of cobalt, ruthenium, rhodium, osmium, and gold are discussed. PMID:16592470

  1. Structure of transition-metal cluster compounds: Use of an additional orbital resulting from the f, g character of spd bond orbitals.

    PubMed

    Pauling, L

    1977-12-01

    A general theory of the structure of complexes of the transition metals is developed on the basis of the enneacovalence of the metals and the requirements of the electroneutrality principle. An extra orbital may be provided through the small but not negligible amount of f and g character of spd bond orbitals, and an extra electron or electron pair may be accepted in this orbital for a single metal or a cluster to neutralize the positive electric charge resulting from the partial ionic character of the bonds with ligands, such as the carbonyl group. Examples of cluster compounds of cobalt, ruthenium, rhodium, osmium, and gold are discussed.

  2. "I'm Scared of the Disappointment": Young Adult Smokers' Relational Identity Gaps and Management Strategies as Sites of Communication Intervention.

    PubMed

    Stanley, Samantha J; Pitts, Margaret Jane

    2018-02-22

    While cigarette smoking is decreasing among young adults, rates of nicotine consumption through other devices, most notably electronic cigarettes, are on the rise. Framed by communication theory of identity, this study examines young adult smokers' experiences with relational others in regard to their smoking. Focus group discussions and individual interviews convened with 20 young adult cigarette and electronic cigarette smokers revealed identity gaps implicating the relational layer of identity, including personal-relational, enacted-relational, and personal-enacted-relational identity gaps. Participants used communicative and behavioral strategies to manage relational discrepancies. The documented identity gaps and management strategies present opportunities for targeted smoking cessation interventions that amplify dissonance created through identity gaps as a motivational tactic.

  3. Development of refractive X-ray focusing optics at Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Alianelli, L.; Sawhney, K. J. S.; Loader, I. M.; Jenkins, D. W. K.; Stevens, R.; Snigirev, A.; Snigireva, I.

    2007-09-01

    The Diamond Optics & Metrology Group and the collaborators at the STFC Central Microstructure Facility have initiated a program for the design and fabrication of in-line micro- and nano-focusing optics for synchrotron radiation beamlines. The first type of optics fabricated is a kinoform lens in silicon on the same model proposed by K. Evans- Lutterodt et al [Opt. Expr. 11 (2003) 919.]. The fabrication utilised ultra high resolution electron beam lithographic patterning of an electron sensitive SU8 polymer and deep reactive ion etching of silicon. The first test of the focusing properties was performed at the ESRF BM5 optics beamline. In this paper we present details on the design and fabrication, and discuss the test results.

  4. Perspective: Theory and simulation of hybrid halide perovskites

    PubMed Central

    Jung, Young-Kwang

    2017-01-01

    Organic-inorganic halide perovskites present a number of challenges for first-principles atomistic materials modeling. Such “plastic crystals” feature dynamic processes across multiple length and time scales. These include the following: (i) transport of slow ions and fast electrons; (ii) highly anharmonic lattice dynamics with short phonon lifetimes; (iii) local symmetry breaking of the average crystallographic space group; (iv) strong relativistic (spin-orbit coupling) effects on the electronic band structure; and (v) thermodynamic metastability and rapid chemical breakdown. These issues, which affect the operation of solar cells, are outlined in this perspective. We also discuss general guidelines for performing quantitative and predictive simulations of these materials, which are relevant to metal-organic frameworks and other hybrid semiconducting, dielectric and ferroelectric compounds. PMID:29166078

  5. Phase Grouping of Larmor Electrons by a Synchronous Wave in Controlled Magnetrons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kazakevich, G.; Johnson, R.; Lebedev, V.

    A simplified analytical model based on the charge drift approximation has been developed. It considers the resonant interaction of the synchronous wave with the flow of Larmor electrons in a magnetron. The model predicts stable coherent generation of the tube above and below the threshold of self-excitation. This occurs if the magnetron is driven by a sufficient resonant injected signal (up to -10 dB). The model substantiates precise stability, high efficiency and low noise at the range of the magnetron power control over 10 dB by variation of the magnetron current. The model and the verifying experiments with 2.45 GHz,more » 1 kW magnetrons are discussed.« less

  6. EELS from organic crystalline materials

    NASA Astrophysics Data System (ADS)

    Brydson, R.; Eddleston, M. D.; Jones, W.; Seabourne, C. R.; Hondow, N.

    2014-06-01

    We report the use of the electron energy loss spectroscopy (EELS) for providing light element chemical composition information from organic, crystalline pharmaceutical materials including theophylline and paracetamol and discuss how this type of data can complement transmission electron microscopy (TEM) imaging and electron diffraction when investigating polymorphism. We also discuss the potential for the extraction of bonding information using electron loss near-edge structure (ELNES).

  7. Group dynamics for the acquisition of competences in Project Management

    NASA Astrophysics Data System (ADS)

    Taguas, E. V.; Aguilar, M. C.; Castillo, C.; Polo, M. J.; Pérez, R.

    2012-04-01

    The Bologna Process promotes European citizens' employability from teaching fields in the University which implies the design of activities addressed to the development of skills for the labor market and engagement of employers. This work has been conceived for improving the formation of Engineering Project Management through group dynamics focused on: 1) the use of the creativity for solving problems; 2) promoting leadership capacities and social skills in multidisciplinary/multicultural work groups; 3) the ethical, social and environmental compromise; 4) the continuous learning. Different types of activities were designed: short activities of 15-30 minutes where fragments of books or songs are presented and discussed and long activities (2 h) where groups of students take different roles for solving common problems and situations within the Engineering Projects context. An electronic book with the content of the dynamics and the material for the students has been carried out. A sample of 20 students of Electronic Engineering degree which had participated at least in two dynamics, evaluated the utility for improving their formation in Engineering Project Management with a mark of 8.2 (scale 0-10, standard deviation equal to 0.9). On the other hand, the teachers observed how this type of work, promotes the interdisciplinary training and the acquisition of social skills, usually not-included in the objectives of the subjects.

  8. Collection Development for the Electronic Library.

    ERIC Educational Resources Information Center

    Herzog, Kate

    1990-01-01

    Summarizes issues discussed at an institute held at Cornell University on the impact of electronic publishing on library collection development. Topics discussed include libraries of the future; the National Research and Education Network (NREN); a definition of an electronic library; scholarly communication; implications of national networks; and…

  9. X-ray magnetic circular dichroism in d and f ferromagnetic materials: recent theoretical progress. Part II (Review Article)

    NASA Astrophysics Data System (ADS)

    Antonov, V. N.; Shpak, A. P.; Yaresko, A. N.

    2008-02-01

    The present state of theoretical understanding of the x-ray magnetic circular dichroism (XMCD) of 4f and 5f compounds is reviewed. Energy band theory based upon the local spin-density approximation (LSDA) describes the XMCD spectra of transition metal compounds with high accuracy. However, the LSDA does not suffice for lanthanide compounds which have a correlated 4f shell. A satisfactory description of the XMCD spectra could be obtained by using a generalization of the LSDA, in which explicitly f electron Coulomb correlations are taken into account (LSDA +U approach). As examples of this group we consider the compound GdN. We also consider uranium 5f compounds. In those compounds where the 5f electrons are rather delocalized, the LSDA describes the XMCD spectra reasonably well. As an example of this group we consider UFe2. Particular differences occur for uranium compounds in which the 5f electrons are neither delocalized nor localized, but more or less semilocalized. Typical examples are UXAl (X =Co, Rh, and Pt), and UX (X =S, Se, Te). However, the semilocalized 5f's are not inert, but their interaction with conduction electrons plays an important role. We also consider the electronic structure and XMCD spectra of the heavy-fermion compounds UPt3, URu2Si2, UPd2Al3, UNi2Al3, and UBe13, where the degree of the 5f localization is increased in comparison with other uranium compounds. The electronic structure and XMCD spectra of UGe2 which possesses simultaneously ferromagnetism and superconductivity also presented. Recently achieved improvements for describing 5f compounds are discussed.

  10. Contributions to the second workshop on medium energy electron cooling - MEEC96

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    MacLachlan, J.

    1997-09-01

    MEEC96 was a workshop devoted primarily to discussion within four working groups, not a mini-conference of prepared reports. Therefore, although there are contributions bearing the name of a single author, much of what was learned came in extemporaneous discussion of the issues posed to the participants. The original plan to produce formal proceedings has been dropped because of the limited number of participants willing to write up their own contributions and because of the difficulty of converting free-wheeling discussion to the written word. The premsise for the 1996 gathering was to set a critique of Fermilab`s R&D effort at coolingmore » a ring of 8 GeV {bar p}`s. Separate abstracts have been submitted to the energy database for contributions to this workshop.« less

  11. Ethical, legal, and social implications of incorporating genomic information into electronic health records.

    PubMed

    Hazin, Ribhi; Brothers, Kyle B; Malin, Bradley A; Koenig, Barbara A; Sanderson, Saskia C; Rothstein, Mark A; Williams, Marc S; Clayton, Ellen W; Kullo, Iftikhar J

    2013-10-01

    The inclusion of genomic data in the electronic health record raises important ethical, legal, and social issues. In this article, we highlight these challenges and discuss potential solutions. We provide a brief background on the current state of electronic health records in the context of genomic medicine, discuss the importance of equitable access to genome-enabled electronic health records, and consider the potential use of electronic health records for improving genomic literacy in patients and providers. We highlight the importance of privacy, access, and security, and of determining which genomic information is included in the electronic health record. Finally, we discuss the challenges of reporting incidental findings, storing and reinterpreting genomic data, and nondocumentation and duty to warn family members at potential genetic risk.

  12. Particle precipitation prior to large earthquakes of both the Sumatra and Philippine Regions: A statistical analysis

    NASA Astrophysics Data System (ADS)

    Fidani, Cristiano

    2015-12-01

    A study of statistical correlation between low L-shell electrons precipitating into the atmosphere and strong earthquakes is presented. More than 11 years of the Medium Energy Protons Electrons Detector data from the NOAA-15 Sun-synchronous polar orbiting satellite were analysed. Electron fluxes were analysed using a set of adiabatic coordinates. From this, significant electron counting rate fluctuations were evidenced during geomagnetic quiet periods. Electron counting rates were compared to earthquakes by defining a seismic event L-shell obtained radially projecting the epicentre geographical positions to a given altitude towards the zenith. Counting rates were grouped in every satellite semi-orbit together with strong seismic events and these were chosen with the L-shell coordinates close to each other. NOAA-15 electron data from July 1998 to December 2011 were compared for nearly 1800 earthquakes with magnitudes larger than or equal to 6, occurring worldwide. When considering 30-100 keV precipitating electrons detected by the vertical NOAA-15 telescope and earthquake epicentre projections at altitudes greater that 1300 km, a significant correlation appeared where a 2-3 h electron precipitation was detected prior to large events in the Sumatra and Philippine Regions. This was in physical agreement with different correlation times obtained from past studies that considered particles with greater energies. The Discussion below of satellite orbits and detectors is useful for future satellite missions for earthquake mitigation.

  13. Designing Electronic Books.

    ERIC Educational Resources Information Center

    Barker, Philip; Manji, Karim

    1991-01-01

    Discussion of the design of interactive environments focuses on three types of electronic book metaphors that use optical discs and can facilitate computer-based learning: (1) static picture books, (2) moving picture books, and (3) multimedia books. Guidelines for designing electronic books are presented, and future directions are discussed. (17…

  14. Novel growth techniques of group-IV based semiconductors on insulator for next-generation electronics

    NASA Astrophysics Data System (ADS)

    Miyao, Masanobu; Sadoh, Taizoh

    2017-05-01

    Recent progress in the crystal growth of group-IV-based semiconductor-on-insulators is reviewed from physical and technological viewpoints. Liquid-phase growth based on SiGe-mixing-triggered rapid-melting growth enables formation of hybrid (100) (110) (111)-orientation Ge-on-insulator (GOI) structures, which show defect-free GOI with very high carrier mobility (˜1040 cm2 V-1 s-1). Additionally, SiGe mixed-crystals with laterally uniform composition were obtained by eliminating segregation phenomena during the melt-back process. Low-temperature solid-phase growth has been explored by combining this process with ion-beam irradiation, additional doping of group-IV elements, metal induced lateral crystallization with/without electric field, and metal-induced layer exchange crystallization. These efforts have enabled crystal growth on insulators below 400 °C, achieving high carrier mobility (160-320 cm2 V-1 s-1). Moreover, orientation-controlled SiGe and Ge films on insulators have been obtained below the softening temperatures of conventional plastic films (˜300 °C). Detailed characterization provides an understanding of physical phenomena behind these crystal growth techniques. Applying these methods when fabricating next-generation electronics is also discussed.

  15. Novel High Efficient Organic Photovoltaic Materials: Appendix for Summary of Research. Appendix

    NASA Technical Reports Server (NTRS)

    Sun, Sam

    2002-01-01

    There are many different kinds of conjugated polymers that may be useful in photovoltaic devices. So far, the most popular and successful conjugated polymers used in photovoltaic devices include poly(1,4-)phenylenevinylenes (PPV), C60 and their derivatives. The discovery of electro-luminescence in PPV has stimulated a great deal of interest in developing "plastic" solid-state semiconductor devices. The overall synthetic methodology for the preparation of PPV can be divided into three main categories: (1) side chain derivatization, (2) precursor approach, and (3) in-situ polymerization. In this project, the first method was adopted. As discussed in project proposal and literatures, the overall efficiency of photovoltaic devices containing conjugated polymers is determined by the materials ability to generate excitons from incoming radiation, and then to separate the charges at donor/acceptor interfaces, and then to transport charges to respective electrodes. Given that effective exciton diffusion range are typical less then 30 nm, unique morphological structures are needed. This need led to several research groups to the idea that interpenetrating or bi-continuous networks of donor (electron donating) and acceptor (electron withdrawing) polymers should give better results. One approach involved the use of functionalized PPV. The attachment of electron withdrawing cyano groups to a PPV forms the CN-PPV, making it a strong electron acceptor. Underivatized PPV is a generally considered a hole-transporting material. Using blends of MEH-PPV, a soluble donor PPV derivative, as a hole transporter and CN-PPV as an electron transporter, a quantum efficiencies of up to 6% was achieved.

  16. Laser wakefield accelerated electron beam monitoring and control

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koga, J. K.; Mori, M.; Kotaki, H.

    2016-03-25

    We will discuss our participation in the ImPACT project, which has as one of its goals the development of an ultra-compact electron accelerator using lasers (< 1 GeV, < 10   m) and the generation of an x-ray beam from the accelerated electrons. Within this context we will discuss our investigation into electron beam monitoring and control. Since laser accelerated electrons will be used for x-ray beam generation combined with an undulator, we will present investigation into the possibilities of the improvement of electron beam emittance through cooling.

  17. Crystal engineering, structure–function relationships, and the future of metal–organic frameworks

    DOE PAGES

    Allendorf, Mark D.; Stavila, Vitalie

    2014-10-15

    Metal-Organic Frameworks (MOFs) are a rapidly expanding class of hybrid organic-inorganic materials that can be rationally designed and assembled through crystal engineering. The explosion of interest in this subclass of coordination polymers results from their outstanding properties and myriad possible applications that include traditional uses of microporous materials, such as gas storage, separations, and catalysis, to new realms in biomedicine, electronic devices, and and information storage. The objective of this Highlight article is to provide the reader with a sense of where the field stands after roughly fifteen years of research. Remarkable progress has been made, but the barriers tomore » practical and commercial advances are also illuminated. We discuss the basic elements of MOF assembly and present a conceptual hierarchy of structural elements that assists in understanding how unique properties in these materials can be achieved. Structure-function relationships are then discussed; several are now well understood as a result of the focused efforts of many research groups over the past decade. Prospects for practical applications of MOFs in membranes, catalysis, biomedicine, and as active components in electronic and photonic devices are also discussed. Finally, we list key challenges that, in our view, must be addressed for these materials to realize their full potential in the marketplace.« less

  18. From EDI to Internet Commerce: The BHP Steel Experience.

    ERIC Educational Resources Information Center

    Chan, Caroline; Swatman, Paula M. C.

    2000-01-01

    Discusses the issue of business-to-business electronic commerce implementation and the factors affecting it. Discusses electronic data interchange technology, describes the results of a case study of BHP Steel (Australia), and considers paradigm shifts in implementation issues related to electronic commerce that occur over time. (Author/LRW)

  19. 76 FR 72087 - Special Conditions: Diamond Aircraft Industries, Model DA-40NG; Electronic Engine Control (EEC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... engine design certification, and the certification requirements for engine control systems are driven by... following novel or unusual design features: Electronic engine control system. Discussion As discussed above...; Electronic Engine Control (EEC) System AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final...

  20. 500 C Electronic Packaging and Dielectric Materials for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Chen, Liang-yu; Neudeck, Philip G.; Spry, David J.; Beheim, Glenn M.; Hunter, Gary W.

    2016-01-01

    High-temperature environment operable sensors and electronics are required for exploring the inner solar planets and distributed control of next generation aeronautical engines. Various silicon carbide (SiC) high temperature sensors, actuators, and electronics have been demonstrated at and above 500C. A compatible packaging system is essential for long-term testing and application of high temperature electronics and sensors. High temperature passive components are also necessary for high temperature electronic systems. This talk will discuss ceramic packaging systems developed for high temperature electronics, and related testing results of SiC circuits at 500C and silicon-on-insulator (SOI) integrated circuits at temperatures beyond commercial limit facilitated by these high temperature packaging technologies. Dielectric materials for high temperature multilayers capacitors will also be discussed. High-temperature environment operable sensors and electronics are required for probing the inner solar planets and distributed control of next generation aeronautical engines. Various silicon carbide (SiC) high temperature sensors, actuators, and electronics have been demonstrated at and above 500C. A compatible packaging system is essential for long-term testing and eventual applications of high temperature electronics and sensors. High temperature passive components are also necessary for high temperature electronic systems. This talk will discuss ceramic packaging systems developed for high electronics and related testing results of SiC circuits at 500C and silicon-on-insulator (SOI) integrated circuits at temperatures beyond commercial limit facilitated by high temperature packaging technologies. Dielectric materials for high temperature multilayers capacitors will also be discussed.

  1. Instrumentation for Studies of Electron Emission and Charging From Insulators

    NASA Technical Reports Server (NTRS)

    Thomson, C. D.; Zavyalov, V.; Dennison, J. R.

    2004-01-01

    Making measurements of electron emission properties of insulators is difficult since insulators can charge either negatively or positively under charge particle bombardment. In addition, high incident energies or high fluences can result in modification of a material s conductivity, bulk and surface charge profile, structural makeup through bond breaking and defect creation, and emission properties. We discuss here some of the charging difficulties associated with making insulator-yield measurements and review the methods used in previous studies of electron emission from insulators. We present work undertaken by our group to make consistent and accurate measurements of the electron/ion yield properties for numerous thin-film and thick insulator materials using innovative instrumentation and techniques. We also summarize some of the necessary instrumentation developed for this purpose including fast response, low-noise, high-sensitivity ammeters; signal isolation and interface to standard computer data acquisition apparatus using opto-isolation, sample-and-hold, and boxcar integration techniques; computer control, automation and timing using Labview software; a multiple sample carousel; a pulsed, compact, low-energy, charge neutralization electron flood gun; and pulsed visible and UV light neutralization sources. This work is supported through funding from the NASA Space Environments and Effects Program and the NASA Graduate Research Fellowship Program.

  2. One of several ‘toys’ for smoking: young adult experiences with electronic cigarettes in New York City

    PubMed Central

    McDonald, Emily Anne; Ling, Pamela M.

    2015-01-01

    Objective This qualitative research explores the use of electronic cigarettes and other similar ‘vapor’ delivery devices among young adults in New York City. Methods We employed 17 focus groups followed by 12 semistructured interviews to understand the beliefs, opinions and practices related to the use of electronic cigarettes among young adult smokers (N=87). Results Participants were mainly daily (52%) and non-daily (41%) smokers. While experimentation with electronic cigarette devices was frequently reported, participants related an overall lack of information about the devices and what they did know often reflected messages in e-cigarette marketing campaigns. Participants also used their own bodily sensations as a way to gauge potential risks and benefits of the products. Finally, young adults, steeped in a culture of personal technologies, perceived e-cigarettes as one more ‘toy’ among other technologies integrated into their everyday lives. Discussion E-cigarettes were also frequently used with other tobacco products, including conventional cigarettes. Our research indicates that public health campaigns may be needed to counter current industry marketing and inform the public that electronic cigarettes are currently unregulated, understudied and contain toxicants and carcinogens. PMID:25564287

  3. Inverse Perovskites - A New Platform For 3D Dirac Electron Physics

    NASA Astrophysics Data System (ADS)

    Rost, A. W.; Kim, J.; Shota, S.; Hayama, K.; Abdolazimi, V.; Bruin, J. A. N.; Muehle, C.; Schnyder, A.; Yaresko, A. N.; Nuss, J.; Takagi, H.

    3D Dirac semimetals show a wealth of phenomena including ultrahigh mobility, extreme transverse magnetoresistance and potential for negative longitudinal magnetoresistance. Furthermore, by introducing a gap these are often found to be topological crystalline insulators. Here, I will introduce our experiments on a new family of 3D Dirac materials - the inverse perovskites A3BO (A =Ca,Sr,Eu/B =Pb,Sn). These open up the possibility to chemically control the properties of Dirac electrons including (i) the anisotropy of the Dirac dispersion, (ii) role of spin orbit coupling, and (iii) magnetism. Our physical property measurements show all (Ca/Sr)3(Pb/Sn)O compounds host Dirac electrons at the Fermi energy with no other bands crossing EF. Quantum oscillations unveil small Fermi surfaces (frequencies <5 T) and light carriers (<0.02 me) only consistent with Dirac electrons. With the successful synthesis of Sr3Pb0.5Sn0.5O this group of materials therefore offers a unique chemical control over the physical properties of 3D Dirac electrons. Crucially, Eu3(Pb/Sn)O compounds allow for the introduction of magnetism. I will discuss the implications of this in particular with respect to surface states in these topological crystalline insulators.

  4. Reducing electronic media use in 2-3 year-old children: feasibility and efficacy of the Family@play pilot randomised controlled trial.

    PubMed

    Hinkley, Trina; Cliff, Dylan P; Okely, Anthony D

    2015-08-14

    Participation in electronic media use among 2-3 year olds is high and associated with adverse health and developmental outcomes. This study sought to test the feasibility and potential efficacy of a family-based program to decrease electronic media (EM) use in 2-3-year-old children. Family@play was a six-session pilot randomised controlled trial delivered to parents of 2-3 year-old children from August to September 2012 in a community environment in the Illawarra region of New South Wales, Australia. Development of program content was guided by Social Cognitive and Family Systems Theories. The primary outcome was children's electronic media use. Secondary outcomes included children's time in sitting, standing and stepping. Data collectors were blinded to group allocation. Parents completed comprehensive process evaluation measures and participated in focus group discussions following completion of the program. Regression analyses were undertaken and effect sizes calculated using principles of intention to treat. Twenty-two participants (n = 12 intervention; n = 10 control) provided complete baseline data; complete data from 16 participants (n = 6 intervention; n = 10 control) were available post-intervention. Process evaluation results were high, showing the acceptability of the program. Compared with children in the control group, there were greater decreases in total EM use among children in the intervention group (adjusted difference [95 % CI] = -31.2 mins/day [-71.0-8.6] Cohen's d = 0.70). Differences for other outcomes were in the hypothesised direction and ranged from small for postural (sitting, standing, stepping) outcomes to moderate to large for individual electronic media (e.g. TV viewing, DVD/video viewing). This is the first family-based study to engage families of 2-3 year old children outside the United States and target multiple EM behaviours. Family@play was shown to be a feasible and acceptable intervention to deliver to families of 2-3 year old children. Potential efficacy is evident from moderate to large effect sizes. A larger trial is warranted to test the efficacy of the program. Australian New Zealand Clinical Trials Registry ( ACTRN12612000470897 ).

  5. Electronic and atomic kinetics in solids irradiated with free-electron lasers or swift-heavy ions

    NASA Astrophysics Data System (ADS)

    Medvedev, N.; Volkov, A. E.; Ziaja, B.

    2015-12-01

    In this brief review we discuss the transient processes in solids under irradiation with femtosecond X-ray free-electron-laser (FEL) pulses and swift-heavy ions (SHI). Both kinds of irradiation produce highly excited electrons in a target on extremely short timescales. Transfer of the excess electronic energy into the lattice may lead to observable target modifications such as phase transitions and damage formation. Transient kinetics of material excitation and relaxation under FEL or SHI irradiation are comparatively discussed. The same origin for the electronic and atomic relaxation in both cases is demonstrated. Differences in these kinetics introduced by the geometrical effects (μm-size of a laser spot vs nm-size of an ion track) and initial irradiation (photoabsorption vs an ion impact) are analyzed. The basic mechanisms of electron transport and electron-lattice coupling are addressed. Appropriate models and their limitations are presented. Possibilities of thermal and nonthermal melting of materials under FEL and SHI irradiation are discussed.

  6. Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae) in Central Texas Caves

    PubMed Central

    Ledford, Joel; Paquin, Pierre; Cokendolpher, James; Campbell, Josh; Griswold, Charles

    2012-01-01

    Abstract The spider genus Tayshaneta is revised based on results from a three gene phylogenetic analysis (Ledford et al. 2011) and a comprehensive morphological survey using scanning electron (SEM) and compound light microscopy. The morphology and relationships within Tayshaneta are discussed and five species-groups are supported by phylogenetic analyses: the anopica group, the coeca group, the myopica group, the microps group and the sandersi group. Short branch lengths within Tayshaneta contrast sharply with the remaining North American genera and are viewed as evidence for a relatively recent radiation of species. Variation in troglomorphic morphology is discussed and compared to patterns found in other Texas cave invertebrates. Several species previously known as single cave endemics have wider ranges than expected, suggesting that some caves are not isolated habitats but instead form part of interconnected karst networks. Distribution maps are compared with karst faunal regions (KFR’s) in Central Texas and the implications for the conservation and recovery of Tayshaneta species are discussed. Ten new species are described: Tayshaneta archambaulti sp. n., Tayshaneta emeraldae sp. n., Tayshaneta fawcetti sp. n., Tayshaneta grubbsi sp. n., Tayshaneta madla sp. n., Tayshaneta oconnorae sp. n., Tayshaneta sandersi sp. n., Tayshaneta sprousei sp. n., Tayshaneta vidrio sp. n. and Tayshaneta whitei sp. n. The males for three species, Tayshaneta anopica (Gertsch, 1974), Tayshaneta devia (Gertsch, 1974) and Tayshaneta microps (Gertsch, 1974) are described for the first time. Tayshaneta furtiva (Gertsch, 1974) and Tayshaneta uvaldea (Gertsch, 1974) are declared nomina dubia as the female holotypes are not diagnosable and efforts to locate specimens at the type localities were unsuccessful. All Tayshaneta species are thoroughly illustrated, diagnosed and keyed. Distribution maps are also provided highlighting areas of taxonomic ambiguity in need of additional sampling. PMID:22363201

  7. Non-fullerene acceptors for organic solar cells

    NASA Astrophysics Data System (ADS)

    Yan, Cenqi; Barlow, Stephen; Wang, Zhaohui; Yan, He; Jen, Alex K.-Y.; Marder, Seth R.; Zhan, Xiaowei

    2018-03-01

    Non-fullerene acceptors (NFAs) are currently a major focus of research in the development of bulk-heterojunction organic solar cells (OSCs). In contrast to the widely used fullerene acceptors (FAs), the optical properties and electronic energy levels of NFAs can be readily tuned. NFA-based OSCs can also achieve greater thermal stability and photochemical stability, as well as longer device lifetimes, than their FA-based counterparts. Historically, the performance of NFA OSCs has lagged behind that of fullerene devices. However, recent developments have led to a rapid increase in power conversion efficiencies for NFA OSCs, with values now exceeding 13%, demonstrating the viability of using NFAs to replace FAs in next-generation high-performance OSCs. This Review discusses the important work that has led to this remarkable progress, focusing on the two most promising NFA classes to date: rylene diimide-based materials and materials based on fused aromatic cores with strong electron-accepting end groups. The key structure-property relationships, donor-acceptor matching criteria and aspects of device physics are discussed. Finally, we consider the remaining challenges and promising future directions for the NFA OSCs field.

  8. Ionizing radiation measurements using low cost instruments for teaching in college or high-school in Brazil

    NASA Astrophysics Data System (ADS)

    Silva, M. C.; Vilela, D. C.; Migoto, V. G.; Gomes, M. P.; Martin, I. M.; Germano, J. S. E.

    2017-11-01

    Ionizing radiation one of modern physics experimental teaching in colleges and high school can be easily implemented today due to low coasts of detectors and also electronic circuits and data acquisition interfaces. First it is interesting to show to young’s students what is ionizing radiation and from where they appears near ground level? How it is possible to measure these radiations and how to check intensities variation during day, night, dry and wet periods in the same school? For increasing interest and stimulation in others students how to proceed in making the graphics of the ionizing radiation and presenting him in real time using Web internet facilities? Many others facilities like calibration of the detector using low intensities radioactive ionizing radiation sources, make comparison of the measurements and discussions of the results should be possible between many groups of students from several schools in the region of Brazil. This paper presents the experimental procedures including detectors and associated electronic including data acquisition, graphics elaboration and Web internet procedures to discuss and exchanging data measurements from several schools.

  9. Consumers' Use of Personal Electronic Devices in the Kitchen.

    PubMed

    Lando, Amy M; Bazaco, Michael C; Chen, Yi

    2018-02-23

    Smartphones, tablets, and other personal electronic devices have become ubiquitous in Americans' daily lives. These devices are used by people throughout the day, including while preparing food. For example, a device may be used to look at recipes and therefore be touched multiple times during food preparation. Previous research has indicated that cell phones can harbor bacteria, including opportunistic human pathogens such as Staphylococcus and Klebsiella spp. This investigation was conducted with data from the 2016 Food Safety Survey (FSS) and from subsequent focus groups to determine the frequency with which consumers use personal electronic devices in the kitchen while preparing food, the types of devices used, and hand washing behaviors after handling these devices. The 2016 FSS is the seventh wave of a repeated cross-sectional survey conducted by the U.S. Food and Drug Administration in collaboration with the U.S. Department of Agriculture. The goal of the FSS is to evaluate U.S. adult consumer attitudes, behaviors, and knowledge about food safety. The FSS included 4,169 adults that were contacted using a dual-frame (land line and cell phone interviews) random-digit-dial sampling process. The personal electronics module was the first of three food safety topics discussed by each of eight consumer focus groups, which were convened in four U.S. cities in fall 2016. Results from the 2016 FSS revealed that of those individuals who use personal electronic devices while cooking, only about one third reported washing hands after touching the device and before continuing cooking. This proportion is significantly lower than that for self-reported hand washing behaviors after touching risky food products such as raw eggs, meat, chicken, or fish. Results from the focus groups highlight the varied usage of these devices during food preparation and the related strategies consumers are using to incorporate personal electric devices into their cooking routines.

  10. The Impact of Electronic Patient Portals on Patient Care: A Systematic Review of Controlled Trials

    PubMed Central

    Ammenwerth, Elske; Schnell-Inderst, Petra

    2012-01-01

    Background Modern information technology is changing and provides new challenges to health care. The emergence of the Internet and the electronic health record (EHR) has brought new opportunities for patients to play a more active role in his/her care. Although in many countries patients have the right to access their clinical information, access to clinical records electronically is not common. Patient portals consist of provider-tethered applications that allow patients to electronically access health information that are documented and managed by a health care institution. Although patient portals are already being implemented, it is still unclear in which ways these technologies can influence patient care. Objective To systematically review the available evidence on the impact of electronic patient portals on patient care. Methods A systematic search was conducted using PubMed and other sources to identify controlled experimental or quasi-experimental studies on the impact of patient portals that were published between 1990 and 2011. A total of 1,306 references from all the publication hits were screened, and 13 papers were retrieved for full text analysis. Results We identified 5 papers presenting 4 distinct studies. There were no statistically significant changes between intervention and control group in the 2 randomized controlled trials investigating the effect of patient portals on health outcomes. Significant changes in the patient portal group, compared to a control group, could be observed for the following parameters: quicker decrease in office visit rates and slower increase in telephone contacts; increase in number of messages sent; changes of the medication regimen; and better adherence to treatment. Conclusions The number of available controlled studies with regard to patient portals is low. Even when patient portals are often discussed as a way to empower patients and improve quality of care, there is insufficient evidence to support this assumption. PMID:23183044

  11. Individualized Risk Communication and Outreach for Primary Cardiovascular Disease Prevention in Community Health Centers: Randomized Trial.

    PubMed

    Persell, Stephen D; Brown, Tiffany; Lee, Ji Young; Shah, Shreya; Henley, Eric; Long, Timothy; Luther, Stephanie; Lloyd-Jones, Donald M; Jean-Jacques, Muriel; Kandula, Namratha R; Sanchez, Thomas; Baker, David W

    2015-11-01

    Many eligible primary cardiovascular disease prevention candidates are not treated with statins. Electronic health record data can identify patients with increased cardiovascular disease risk. We performed a pragmatic randomized controlled trial at community health centers in 2 states. Participants were men aged ≥35 years and women ≥45 years, without cardiovascular disease or diabetes mellitus, and with a 10-year risk of coronary heart disease of at least 10%. The intervention group received telephone and mailed outreach, individualized based on patients' cardiovascular disease risk and uncontrolled risk factors, provided by lay health workers. Main outcomes included: documented discussion of medication treatment for cholesterol with a primary care clinician, receipt of statin prescription within 6 months, and low-density lipoprotein (LDL)-cholesterol repeated and at least 30 mg/dL lower than baseline within 1 year. Six hundred forty-six participants (328 and 318 in the intervention and control groups, respectively) were included. At 6 months, 26.8% of intervention and 11.6% of control patients had discussed cholesterol treatment with a primary care clinician (odds ratio, 2.79; [95% confidence interval, 2.25-3.46]). Statin prescribing occurred for 10.1% in the intervention group and 6.0% in the control group (odds ratio, 1.76; [95% confidence interval, 0.90-3.45]). The cholesterol outcome did not differ, and the majority of patients did not repeat lipid levels during follow-up. Risk communication and lay outreach increased cholesterol treatment discussions with primary care clinicians. However, most discussions did not result in statin prescribing. For outreach to be successful, it should be combined with interventions to encourage clinicians to follow contemporary risk-based cholesterol treatment guidelines. URL: http://www.clincialtrials.gov. Unique identifier: NCT01610609. © 2015 American Heart Association, Inc.

  12. An Electronic Health Record Data-driven Model for Identifying Older Adults at Risk of Unintentional Falls

    PubMed Central

    Baus, Adam; Coben, Jeffrey; Zullig, Keith; Pollard, Cecil; Mullett, Charles; Taylor, Henry; Cochran, Jill; Jarrett, Traci; Long, Dustin

    2017-01-01

    Screening for risk of unintentional falls remains low in the primary care setting because of the time constraints of brief office visits. National studies suggest that physicians caring for older adults provide recommended fall risk screening only 30 to 37 percent of the time. Given prior success in developing methods for repurposing electronic health record data for the identification of fall risk, this study involves building a model in which electronic health record data could be applied for use in clinical decision support to bolster screening by proactively identifying patients for whom screening would be beneficial and targeting efforts specifically to those patients. The final model, consisting of priority and extended measures, demonstrates moderate discriminatory power, indicating that it could prove useful in a clinical setting for identifying patients at risk of falls. Focus group discussions reveal important contextual issues involving the use of fall-related data and provide direction for the development of health systems–level innovations for the use of electronic health record data for fall risk identification. PMID:29118679

  13. Pertinent parameters in photo-generation of electrons: Comparative study of anatase-based nano-TiO2 suspensions.

    PubMed

    Martel, D; Guerra, A; Turek, P; Weiss, J; Vileno, B

    2016-04-01

    In the field of solar fuel cells, the development of efficient photo-converting semiconductors remains a major challenge. A rational analysis of experimental photocatalytic results obtained with material in colloïdal suspensions is needed to access fundamental knowledge required to improve the design and properties of new materials. In this study, a simple system electron donor/nano-TiO2 is considered and examined via spin scavenging electron paramagnetic resonance as well as a panel of analytical techniques (composition, optical spectroscopy and dynamic light scattering) for selected type of nano-TiO2. Independent variables (pH, electron donor concentration and TiO2 amount) have been varied and interdependent variables (aggregate size, aggregate surface vs. volume and acid/base groups distribution) are discussed. This work shows that reliable understanding involves thoughtful combination of interdependent parameters, whereas the specific surface area seems not a pertinent parameter. The conclusion emphasizes the difficulty to identify the key features of the mechanisms governing photocatalytic properties in nano-TiO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Quantifying TEMPO Redox Polymer Charge Transport toward the Organic Radical Battery.

    PubMed

    Karlsson, Christoffer; Suga, Takeo; Nishide, Hiroyuki

    2017-03-29

    To design new and better organic active battery materials in a rational fashion, fundamental parameters of the charge transport must be studied. Herein we report on the electronic conductivity by electron diffusion in a TEMPO-containing redox polymer, and the reorganization energy of the TEMPO self-exchange in an organic solvent is determined for the first time. The electronic conductivity was 8.5 μS/cm at E 0 and corresponded to a redox hopping mechanism. The apparent electron diffusion coefficient was 1.9 × 10 -9 cm 2 /s at room temperature, and at short times the ion diffusion was limiting with a diffusion coefficient of 6.5 × 10 -10 cm 2 /s. The reorganization energy was determined to be 1.01 eV, indicating a rather polar chemical environment for the TEMPO groups. The implications for the usage of this type of materials in organic energy storage are discussed. As conductivity through 10 μm was demonstrated, we show that, if sufficient swellability can be ensured, charge can be transported through several micrometer thick layers in a battery electrode without any conducting additive.

  15. Two-dimensional hybrid Monte Carlo–fluid modelling of dc glow discharges: Comparison with fluid models, reliability, and accuracy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eylenceoğlu, E.; Rafatov, I., E-mail: rafatov@metu.edu.tr; Kudryavtsev, A. A.

    2015-01-15

    Two-dimensional hybrid Monte Carlo–fluid numerical code is developed and applied to model the dc glow discharge. The model is based on the separation of electrons into two parts: the low energetic (slow) and high energetic (fast) electron groups. Ions and slow electrons are described within the fluid model using the drift-diffusion approximation for particle fluxes. Fast electrons, represented by suitable number of super particles emitted from the cathode, are responsible for ionization processes in the discharge volume, which are simulated by the Monte Carlo collision method. Electrostatic field is obtained from the solution of Poisson equation. The test calculations weremore » carried out for an argon plasma. Main properties of the glow discharge are considered. Current-voltage curves, electric field reversal phenomenon, and the vortex current formation are developed and discussed. The results are compared to those obtained from the simple and extended fluid models. Contrary to reports in the literature, the analysis does not reveal significant advantages of existing hybrid methods over the extended fluid model.« less

  16. A new species of Dianthus (Caryophyllaceae) from Antalya, South Anatolia, Turkey.

    PubMed

    Deniz, İsmail Gökhan; Aykurt, Candan; Genç, İlker; Aksoy, Ahmet

    2016-01-01

    Dianthus multiflorus from Gazipaşa (Antalya), south Anatolia (Turkey), is described as a new annual species with verrucose calyx. The morphological differences from the species within the same group with Dianthus multiflorus, which are Dianthus aydogdui, Dianthus cyri and Dianthus tripunctatus, are discussed. The International Union for Conservation of Nature (IUCN) threat category and observations on the ecology of the populations are noted. The karyology and seed micromorphology of Dianthus multiflorus and Dianthus tripunctatus were examined by light microscopy and scanning electron microscopy.

  17. Structural and magnetic studies of nanocrystalline Y{sub 2}Ir{sub 2}O{sub 7}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dwivedi, Vinod Kumar, E-mail: vinodd@iitk.ac.in; Mukhopadhyay, Soumik

    2015-06-24

    In this paper, we discuss synthesis of Y{sub 2}Ir{sub 2}O{sub 7} nanoparticles via chemical solution process. Structural analysis shows single cubic phase with Fd-3m space group symmetry. The particle size and distribution were studied by Transmission Electron Microscopy experiments. The average particle size turns out to be 50nm, which is in good agreement with the XRD results. Magnetic characterization shows no evidence of long range ordering even in presence of strong correlations.

  18. Activities report in nuclear physics and particle acceleration

    NASA Astrophysics Data System (ADS)

    Jansen, J. F. W.; Demeijer, R. J.

    1984-04-01

    Research on nuclear resonances; charge transfer; breakup of light and heavy ions; reaction mechanisms of heavy ion collisions; high-spin states; and fundamental symmetries in weak interactions are outlined. Group theoretical methods applied to supersymmetries; phenomenological description of rotation-vibration coupling; a microscopic theory of collective variables; the binding energy of hydrogen adsorbed on stepped platinium; and single electron capture are discussed. Isotopes for nuclear medicine, for off-line nuclear spectroscopy work, and for the study of hyperfine interactions were produced.

  19. Making sense of the electronic resource marketplace: trends in health-related electronic resources.

    PubMed Central

    Blansit, B D; Connor, E

    1999-01-01

    Changes in the practice of medicine and technological developments offer librarians unprecedented opportunities to select and organize electronic resources, use the Web to deliver content throughout the organization, and improve knowledge at the point of need. The confusing array of available products, access routes, and pricing plans makes it difficult to anticipate the needs of users, identify the top resources, budget effectively, make sound collection management decisions, and organize the resources effectively and seamlessly. The electronic resource marketplace requires much vigilance, considerable patience, and continuous evaluation. There are several strategies that librarians can employ to stay ahead of the electronic resource curve, including taking advantage of free trials from publishers; marketing free trials and involving users in evaluating new products; watching and testing products marketed to the clientele; agreeing to beta test new products and services; working with aggregators or republishers; joining vendor advisory boards; benchmarking institutional resources against five to eight competitors; and forming or joining a consortium for group negotiating and purchasing. This article provides a brief snapshot of leading biomedical resources; showcases several libraries that have excelled in identifying, acquiring, and organizing electronic resources; and discusses strategies and trends of potential interest to biomedical librarians, especially those working in hospital settings. PMID:10427421

  20. Small-Scale Dayside Magnetic Reconnection Analysis via MMS

    NASA Astrophysics Data System (ADS)

    Pritchard, K. R.; Burch, J. L.; Fuselier, S. A.; Webster, J.; Genestreti, K.; Torbert, R. B.; Rager, A. C.; Phan, T.; Argall, M. R.; Le Contel, O.; Russell, C. T.; Strangeway, R. J.; Giles, B. L.

    2017-12-01

    The Magnetospheric Multiscale (MMS) mission has the primary objective of understanding the physics of the reconnection electron diffusion region (EDR), where magnetic energy is transformed into particle energy. In this poster, we present data from an EDR encounter that occurred in late December 2016 at approximately 11:00 MLT with a moderate guide field. The spacecraft were in a tetrahedral formation with an average inter-spacecraft distance of approximately 7 kilometers. During this event electron crescent-shaped distributions were observed in the electron stagnation region as is typical for asymmetric reconnection. Based on the observed ion velocity jets, the spacecraft traveled just south of the EDR. Because of the close spacecraft separation, fairly accurate computation of the Hall, electron pressure divergence, and electron inertia components of the reconnection electric field could be made. In the region of the crescent distributions good agreement was observed, with the strongest component being the normal electric field and the most significant sources being electron pressure divergence and the Hall electric field. While the strongest currents were in the out-of-plane direction, the dissipation was strongest in the normal direction because of the larger magnitude of the normal electric field component. These results are discussed in light of recent 3D PIC simulations performed by other groups.

  1. Making sense of the electronic resource marketplace: trends in health-related electronic resources.

    PubMed

    Blansit, B D; Connor, E

    1999-07-01

    Changes in the practice of medicine and technological developments offer librarians unprecedented opportunities to select and organize electronic resources, use the Web to deliver content throughout the organization, and improve knowledge at the point of need. The confusing array of available products, access routes, and pricing plans makes it difficult to anticipate the needs of users, identify the top resources, budget effectively, make sound collection management decisions, and organize the resources effectively and seamlessly. The electronic resource marketplace requires much vigilance, considerable patience, and continuous evaluation. There are several strategies that librarians can employ to stay ahead of the electronic resource curve, including taking advantage of free trials from publishers; marketing free trials and involving users in evaluating new products; watching and testing products marketed to the clientele; agreeing to beta test new products and services; working with aggregators or republishers; joining vendor advisory boards; benchmarking institutional resources against five to eight competitors; and forming or joining a consortium for group negotiating and purchasing. This article provides a brief snapshot of leading biomedical resources; showcases several libraries that have excelled in identifying, acquiring, and organizing electronic resources; and discusses strategies and trends of potential interest to biomedical librarians, especially those working in hospital settings.

  2. Harmonic cascade FEL designs for LUX

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Penn, G.; Reinsch, M.; Wurtele, J.

    LUX is a design concept for an ultrafast X-ray science facility, based on an electron beam accelerated to GeV energies in are circulating linac. Included in the design are short duration (200 fs or shorter FWHM) light sources using multiple stages of higher harmonic generation, seeded by a 200-250 nm laser of similar duration. This laser modulates the energy of a group of electrons within the electron bunch; this section of the electron bunch then produces radiation at a higher harmonic after entering a second, differently tuned undulator. Repeated stages in a cascade yield increasing photon energies up to 1more » keV. Most of the undulators in the cascade operate in the low-gain FEL regime. Harmonic cascades have been designed for each pass of the recirculating linac up to a final electron beam energy of 3.1 GeV. For a given cascade, the photon energy can be selected over a wide range by varying the seed laser frequency and the field strength in the undulators. We present simulation results using the codes GENESIS and GINGER, as well as the results of analytical models which predict FEL performance. We discuss lattice considerations pertinent for harmonic cascade FELs, as well as sensitivity studies and requirements on the electron beam.« less

  3. Synthesis and Pharmacology of 1-Alkyl-3-(1-naphthoyl)indoles: Steric and Electronic Effects of 4- and 8-Halogenated Naphthoyl Substituents.

    PubMed Central

    Wiley, Jenny L.; Smith, Valerie J.; Chen, Jianhong; Martin, Billy R.; Huffman, John W.

    2012-01-01

    To develop SAR at both the cannabinoid CB1 and CB2 receptors for 3-(1-naphthoyl)indoles bearing moderately electron withdrawing substituents at C-4 of the naphthoyl moiety, 1-propyl and 1-pentyl-3-(4-fluoro, chloro, bromo and iodo-1-naphthoyl) derivatives were prepared. To study the steric and electronic effects of substituents at the 8-position of the naphthoyl group, the 3-(4-chloro, bromo and iodo-1-naphthoyl)indoles were also synthesized. The affinities of both groups of compounds for the CB1 and CB2 receptors were determined and several of them were evaluated in vivo in the mouse. The effects of these substituents on receptor affinities and in vivo activity are discussed and structure-activity relationships are presented. Although many of these compounds are selective for the CB2 receptor, only three JWH-423, 1-propyl-3-(4-iodo-1-naphthoyl)indole, JWH-422, 2-methyl-1-propyl-3-(4-iodo-1-naphthoyl)indole, the 2-methyl analog of JWH-423 and JWH-417, 1-pentyl-3-(8-iodo-1-naphthoyl)indole, possess the desirable combination of low CB1 affinity and good CB2 affinity. PMID:22341572

  4. Effective bond orders from two-step spin–orbit coupling approaches: The I{sub 2}, At{sub 2}, IO{sup +}, and AtO{sup +} case studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maurice, Rémi, E-mail: remi.maurice@subatech.in2p3.fr; Montavon, Gilles; Réal, Florent

    2015-03-07

    The nature of chemical bonds in heavy main-group diatomics is discussed from the viewpoint of effective bond orders, which are computed from spin–orbit wave functions resulting from spin–orbit configuration interaction calculations. The reliability of the relativistic correlated wave functions obtained in such two-step spin–orbit coupling frameworks is assessed by benchmark studies of the spectroscopic constants with respect to either experimental data, or state-of-the-art fully relativistic correlated calculations. The I{sub 2}, At{sub 2}, IO{sup +}, and AtO{sup +} species are considered, and differences and similarities between the astatine and iodine elements are highlighted. In particular, we demonstrate that spin–orbit coupling weakensmore » the covalent character of the bond in At{sub 2} even more than electron correlation, making the consideration of spin–orbit coupling compulsory for discussing chemical bonding in heavy (6p) main group element systems.« less

  5. Overcoming challenges: life with an ostomy.

    PubMed

    Popek, Sarah; Grant, Marcia; Gemmill, Robin; Wendel, Christopher S; Mohler, M Jane; Rawl, Susan M; Baldwin, Carol M; Ko, Clifford Y; Schmidt, C Max; Krouse, Robert S

    2010-11-01

    Studies have demonstrated decreased health-related quality of life in patients with stomas. Using US Department of Veterans Affairs electronic medical records, veterans with stomas were surveyed using the City of Hope Quality of Life-Ostomy questionnaire. Focus groups were conducted segregated by type of stoma (ileostomy vs colostomy) and quality-of-life score (high vs low). Qualitative analysis was performed on the basis of the City of Hope Quality of Life for Ostomates format of health-related quality of life (physical, psychological, social, and spiritual). The findings of the colostomy focus groups are reported. Two new domains emerged: colostomy specific and health care specific. The most common domains discussed were colostomy specific, psychological, and social. The most frequently discussed colostomy-specific theme was effective and ineffective solutions to colostomy care. Family and spousal relationships were the main theme from the psychological category. The predominant social issue was sexual relationships. Awareness of patients' social, psychological, and medical status allows surgeons to identify those likely to have problems and devote resources to those veterans. Published by Elsevier Inc.

  6. Directory of Electronic Journals, Newsletters and Academic Discussion Lists. 5th Edition.

    ERIC Educational Resources Information Center

    King, Lisabeth A., Comp.; And Others

    This directory is a compilation of entries for nearly 2,500 scholarly discussion lists and 675 electronic journals, newsletters, and related titles such as newsletter-digests, available on the Internet. Instructions are provided for accessing each publication. Part 1 is an introduction to electronic scholarly publications, followed by the articles…

  7. The Contributions of Felix Bloch and W. V. Houston to the Electron Theory of Metals

    ERIC Educational Resources Information Center

    Rorschach, H. E., Jr.

    1970-01-01

    Discusses the contributions of Bloch and Houston to the electron theory of metals. Contains (1) a biographical note on W. V. Houston, (2) a review of the development of the electron theory of metals, and (3) a discussion of gravitationally induced electric fields. Bibliography. (LC)

  8. Splicing Ourselves into the Machine: Electronic Communities, Systems Theory, and Composition Studies.

    ERIC Educational Resources Information Center

    LaGrandeur, Kevin

    Computer mediated communication (CMC) tends to erase power structures because such communication somehow undermines or escapes discursive limits. Online discussions seem to promote rhetorical experimentation on the part of the participants. Finding a way to explain disparities between electronic discussion and oral discussion has proven difficult.…

  9. Two new species of gorgonian octocorals from the Tropical Eastern Pacific Biogeographic Region (Cnidaria, Anthozoa, Gorgoniidae)

    PubMed Central

    Breedy, Odalisca; Williams, Gary C; Guzman, Hector M

    2013-01-01

    Abstract The gorgoniid Eugorgia is exclusively an eastern Pacific genus. It has a wide geographic and bathymetric range of distribution, found from California to Perú and extends down to 65 m deep. Two new species are herein described. The morphological characters were analyzed and illustrated by light and scanning electron microscopy. Eugorgia beebei sp. n. can be distinguished by its white, ascending, sparse colony growth. Eugorgia mutabilis sp. n. can be distinguished by its white colony that changes color after collection, and the conspicuous sharp-crested disc sclerites. From a morphological point of view the new species are related to the daniana-group, the rubens-group and the siedenburgae-group of Eugorgia; their affiliations, and the proposal of a new group are discussed. These new species increases the number of species in the genus to 15, and contribute to the knowledge of the eastern Pacific octocoral biodiversity. PMID:24294084

  10. Report of the Working Group on Space/Lunar Tradeoffs

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The group discussed the advantages and disadvantages of five locations for an optical/infrared array: low-Earth orbit (LEO), Sun-synchronous Earth-orbit, geosynchronous orbit (GEO), Lagrangian points (L4 and L5), and the lunar surface. The factors affecting an array and our assessments of them are given and briefly discussed. In the discussions, two axioms are assumed: (1) Human expansion into space and to the Moon will occur; and (2) The Space Station will be constructed and operational. The major conclusion reached is that baselines of moderate size (greater than 300 m) are best done on the Moon and that large baselines (greater than 10 km) can be done only on the Moon. Three areas needing additional research were identified as follows. (1) Studies are needed on methods to steer long-baseline systems in orbit. This involves learning how to control free-flyers. It is not clear how the difficulty of control varies with orbital elevation. (2) More work is needed on the internal metrology of array systems, both orbital and lunar-surface systems.(3) We need to understand the radiation effects on detectors and electronics and learn how to mitigate them.

  11. An electro-optical and electron injection study of benzothiazole-based squaraine dyes as efficient dye-sensitized solar cell materials: a first principles study.

    PubMed

    Al-Fahdan, Najat Saeed; Asiri, Abdullah M; Irfan, Ahmad; Basaif, Salem A; El-Shishtawy, Reda M

    2014-12-01

    Squaraine dyes have attracted significant attention in many areas of daily life from biomedical imaging to semiconducting materials. Moreover, these dyes are used as photoactive materials in the field of solar cells. In the present study, we investigated the structural, electronic, photophysical, and charge transport properties of six benzothiazole-based squaraine dyes (Cis-SQ1-Cis-SQ3 and Trans-SQ1-Trans-SQ3). The effect of electron donating (-OCH3) and electron withdrawing (-COOH) groups was investigated intensively. Ground state geometry and frequency calculations were performed by applying density functional theory (DFT) at B3LYP/6-31G** level of theory. Absorption spectra were computed in chloroform at the time-dependent DFT/B3LYP/6-31G** level of theory. The driving force of electron injection (ΔG (inject)), relative driving force of electron injection (ΔG r (inject)), electronic coupling constants (|VRP|) and light harvesting efficiency (LHE) of all six compounds were calculated and compared with previously studied sensitizers. The ΔG (inject), ΔG r (inject) and |VRP| of all six compounds revealed that these sensitizers would be efficient dye-sensitized solar cell materials. Cis/Trans-SQ3 exhibited superior LHE as compared to other derivatives. The Cis/Trans geometric effect was studied and discussed with regard to electro-optical and charge transport properties.

  12. Surface contamination analysis technology team overview

    NASA Astrophysics Data System (ADS)

    Burns, H. Dewitt, Jr.

    1996-11-01

    The surface contamination analysis technology (SCAT) team was originated as a working roup of NASA civil service, Space Shuttle contractor, and university groups. Participating members of the SCAT Team have included personnel from NASA Marshall Space Flight Center's Materials and Processes Laboratory and Langley Research Center's Instrument Development Group; contractors-Thiokol Corporation's Inspection Technology Group, AC Engineering support contractor, Aerojet, SAIC, and Lockheed MArtin/Oak Ridge Y-12 support contractor and Shuttle External Tank prime contractor; and the University of Alabama in Huntsville's Center for Robotics and Automation. The goal of the SCAT team as originally defined was to develop and integrate a multi-purpose inspection head for robotic application to in-process inspection of contamination sensitive surfaces. One area of interest was replacement of ozone depleting solvents currently used for surface cleanliness verification. The team approach brought together the appropriate personnel to determine what surface inspection techniques were applicable to multi-program surface cleanliness inspection. Major substrates of interest were chosen to simulate space shuttle critical bonding surface or surfaces sensitive to contamination such as fuel system component surfaces. Inspection techniques evaluated include optically stimulated electron emission or photoelectron emission; Fourier transform infrared spectroscopy; near infrared fiber optic spectroscopy; and, ultraviolet fluorescence. Current plans are to demonstrate an integrated system in MSFC's Productivity Enhancement Complex within five years from initiation of this effort in 1992. Instrumentation specifications and designs developed under this effort include a portable diffuse reflectance FTIR system built by Surface Optics Corporation and a third generation optically stimulated electron emission system built by LaRC. This paper will discuss the evaluation of the various techniques on a number of substrate materials contaminated with hydrocarbons, silicones, and fluorocarbons. Discussion will also include standards development for instrument calibration and testing.

  13. Electronic Interactions of n-Doped Perylene Diimide Groups Appended to Polynorbornene Chains: Implications for Electron Transport in Organic Electronics.

    PubMed

    Nguyen, Minh T; Biberdorf, Joshua D; Holliday, Bradley J; Jones, Richard A

    2017-11-01

    A polymer consisting of a polynorbornene backbone with perylene diimide (PDI) pendant groups on each monomeric unit is synthesized via ring opening metathesis polymerization. The PDI pendant groups along the polymer backbone, studied by UV-vis absorption, fluorescence emission, and electron paramagnetic resonance spectroscopy in addition to electrochemical methods, show evidence of molecular aggregation and corresponding electronic coupling with neighboring groups, which forms pathways for efficient electron transport from one group to another in a specific reduced form. When n-doped, the title polymer shows redox conductivity of 5.4 × 10 -3 S cm -1 , comparable with crystalline PDI materials, and is therefore a promising material for use in organic electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. LDEF electronic systems: Successes, failures, and lessons

    NASA Technical Reports Server (NTRS)

    Miller, Emmett; Porter, Dave; Smith, Dave; Brooks, Larry; Levorsen, Joe; Mulkey, Owen

    1991-01-01

    Following the Long Duration Exposure Facility (LDEF) retrieval, the Systems Special Investigation Group (SIG) participated in an extensive series of tests of various electronic systems, including the NASA provided data and initiate systems, and some experiment systems. Overall, these were found to have performed remarkably well, even though most were designed and tested under limited budgets and used at least some nonspace qualified components. However, several anomalies were observed, including a few which resulted in some loss of data. The postflight test program objectives, observations, and lessons learned from these examinations are discussed. All analyses are not yet complete, but observations to date will be summarized, including the Boeing experiment component studies and failure analysis results related to the Interstellar Gas Experiment. Based upon these observations, suggestions for avoiding similar problems on future programs are presented.

  15. The cosmological lithium problem revisited

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Mukhamedzhanov, A. M.; Shubhchintak

    2016-07-01

    After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

  16. The GAMCIT gamma ray burst detector

    NASA Technical Reports Server (NTRS)

    Mccall, Benjamin J.; Grunsfeld, John M.; Sobajic, Srdjan D.; Chang, Chinley Leonard; Krum, David M.; Ratner, Albert; Trittschuh, Jennifer E.

    1993-01-01

    The GAMCIT payload is a Get-Away-Special payload designed to search for high-energy gamma-ray bursts and any associated optical transients. This paper presents details on the design of the GAMCIT payload, in the areas of battery selection, power processing, electronics design, gamma-ray detection systems, and the optical imaging of the transients. The paper discusses the progress of the construction, testing, and specific design details of the payload. In addition, this paper discusses the unique challenges involved in bringing this payload to completion, as the project has been designed, constructed, and managed entirely by undergraduate students. Our experience will certainly be valuable to other student groups interested in taking on a challenging project such as a Get-Away-Special payload.

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoshitake, Michiko, E-mail: yoshitake.michiko@nims.go.jp

    Transition-metal carbides and nitrides (TMCs and TMNs) are promising electrode materials for various electronic devices such as metal-oxide-semiconductor field-effect transistors and metal-insulator-metal capacitors. In this paper, the work functions of TMCs and TMNs are discussed systematically. Based upon the origin of the work function, the effect upon transition metal species by different periodic table groups is explained, carbides are compared with nitrides for the same transition metal, and the effect of carbon or nitrogen vacancies is discussed. In addition, a method to estimate the generic trend of the work function is proposed for TMC{sub x}, TMN{sub x}, TMC{sub 1−y}N{sub y}more » (transition metal carbonitrides), and TM{sub 1−z}TM′{sub z}C (alloy carbides)« less

  18. A Unified Electronic Tool for CPR and Emergency Treatment Escalation Plans Improves Communication and Early Collaborative Decision Making for Acute Hospital Admissions.

    PubMed

    Johnson, Mae; Whyte, Martin; Loveridge, Robert; Yorke, Richard; Naleem, Shairana

    2017-01-01

    The National Confidential Enquiry into Patient Outcomes and Death (NCEPOD) report 'Time to Intervene' (2012) stated that in a substantial number of cases, resuscitation is attempted when it was thought a 'do not attempt cardiopulmonary resuscitation' (DNACPR) decision should have been in place. Early decisions about CPR status and advance planning about limits of care now form part of national recommendations by the UK Resuscitation Council (2016). Treatment escalation plans (TEP) document what level of treatment intervention would be appropriate if a patient were to become acutely unwell and were not previously formally in place at King's College Hospital. A unifying paper based form was successfully piloted in the Acute Medical Unit, introducing the TEP and bringing together decision making around both treatment escalation and CPR status. Subsequently an electronic order-set for CPR status and treatment escalation was launched in April 2015 which led to a highly visible CPR and escalation status banner on the main screen at the top of the patient's electronic record. Ultimately due to further iterations in the electronic process by December 2016, all escalation decisions for acutely admitted patients now have high quality supporting, explanatory documentation with 100% having TEPs in place. There is now widespread multidisciplinary engagement in the process of defining limits of care for acutely admitted medical patients within the first 14 hours of admission and a strategy for rolling this process out across all the divisions of the hospital through our Deteriorating Patient Group (DPG). The collaborative design with acute medical, palliative and intensive care teams and the high visibility provided by the electronic process in the Electronic Patient Record (EPR) has enhanced communication with these teams, patients, nursing staff and the multidisciplinary team by ensuring clarity through a universally understood process about escalation and CPR. Clarity and openness about these discussions have been welcomed by patient focus groups facilitated via our acute medicine patient experience committee. There has been a shift in medical culture where transparency about limits of care has contributed to improving patient safety and quality of care through reducing unnecessary CPR supported by focus groups of staff.

  19. Improving extreme-scale problem solving: assessing electronic brainstorming effectiveness in an industrial setting.

    PubMed

    Dornburg, Courtney C; Stevens, Susan M; Hendrickson, Stacey M L; Davidson, George S

    2009-08-01

    An experiment was conducted to compare the effectiveness of individual versus group electronic brainstorming to address difficult, real-world challenges. Although industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges during the course of 4 days. Employees and contractors at a national laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a real-world problem. The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly (p < .05) outperformed the group. When quality is used to benchmark success, these data indicate that work-relevant challenges are better solved by aggregating electronic individual responses rather than by electronically convening a group. This research suggests that industrial reliance on electronic problem-solving groups should be tempered, and large nominal groups may be more appropriate corporate problem-solving vehicles.

  20. Exploring practical approaches to maximising data quality in electronic healthcare records in the primary care setting and associated benefits. Report of panel-led discussion held at SAPC in July 2014.

    PubMed

    Dungey, Sheena; Glew, Simon; Heyes, Barbara; Macleod, John; Tate, A Rosemary

    2016-09-01

    Electronic healthcare records provide information about patient care over time which not only affords the opportunity to improve patient care directly through effective monitoring and identification of care requirements but also offers a unique platform for both clinical and service-model research essential to the longer-term development of the health service. The quality of the recorded data can, however, be variable and can compromise the validity of data use both for primary and secondary purposes. In order to explore the challenges and benefits of and approaches to recording high quality primary care electronic records, a Clinical Practice Research Datalink (CPRD) sponsored workshop was held at the Society of Academic Primary Care (SAPC) conference in 2014 with the aim of engaging GPs and other data users. The workshop was held as a structured discussion, led by an expert panel and focused around three questions: (1) What are the data quality priorities for clinicians and researchers? How do these priorities differ or overlap? (2) What challenges might GPs face in provision of good data quality both for treating their patients and for research? Do these aims conflict? (3) What tools (such as data metrics and visualisations or software components) could assist the GP in improving data quality and patient management and could this tie in with analytical processes occurring at the research stage? The discussion highlighted both overlap and differences in the perceived data quality priorities and challenges for different user groups. Five key areas of focus were agreed upon and recommendations determined for moving forward in improving quality. The importance of good high quality electronic healthcare records has been set forth along with the need for a practical user-considered and collaborative approach to its improvement.

  1. Biomolecular damage induced by ionizing radiation: the direct and indirect effects of low-energy electrons on DNA.

    PubMed

    Alizadeh, Elahe; Orlando, Thomas M; Sanche, Léon

    2015-04-01

    Many experimental and theoretical advances have recently allowed the study of direct and indirect effects of low-energy electrons (LEEs) on DNA damage. In an effort to explain how LEEs damage the human genome, researchers have focused efforts on LEE interactions with bacterial plasmids, DNA bases, sugar analogs, phosphate groups, and longer DNA moieties. Here, we summarize the current understanding of the fundamental mechanisms involved in LEE-induced damage of DNA and complex biomolecule films. Results obtained by several laboratories on films prepared and analyzed by different methods and irradiated with different electron-beam current densities and fluencies are presented. Despite varied conditions (e.g., film thicknesses and morphologies, intrinsic water content, substrate interactions, and extrinsic atmospheric compositions), comparisons show a striking resemblance in the types of damage produced and their yield functions. The potential of controlling this damage using molecular and nanoparticle targets with high LEE yields in targeted radiation-based cancer therapies is also discussed.

  2. Recent developments of the in situ wet cell technology for transmission electron microscopies.

    PubMed

    Chen, Xin; Li, Chang; Cao, Hongling

    2015-03-21

    In situ wet cells for transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) allow studying structures and processes in a liquid environment with high temporal and spatial resolutions, and have been attracting increasing research interests in many fields. In this review, we highlight the structural and functional developments of the wet cells for TEM and STEM. One of the key features of the wet cells is the sealing technique used to isolate the liquid sample from the TEM/STEM vacuum environments, thus the existing in situ wet cells are grouped by different sealing methods. In this study, the advantages and shortcomings of each type of in situ wet cells are discussed, the functional developments of different wet cells are presented, and the future trends of the wet cell technology are addressed. It is suggested that in the future the in situ wet cell TEM/STEM technology will have an increasing impact on frontier nanoscale research.

  3. One- and two-dimensional pulse electron paramagnetic resonance spectroscopy: concepts and applications.

    PubMed

    Van Doorslaer, S; Schweiger, A

    2000-06-01

    During the last two decades, the possibilities of pulse electron paramagnetic resonance (EPR) and pulse electron nuclear double resonance (ENDOR) spectroscopy have increased tremendously. While at the beginning of the 1980s pulse-EPR and ENDOR applications were still a rarity, the techniques are now very frequently applied in chemistry, physics, materials science, biology and mineralogy. This is mainly due to the considerable efforts invested in the last few years on instrument development and pulse-sequence design. Pulse-EPR spectrometers are now commercially available, which enables many research groups to use these techniques. In this work, an overview of state-of-the-art pulse EPR and ENDOR spectroscopy is given. The rapid expansion of the field, however, does not allow us to give an exhaustive record of all the pulse methods introduced so far. After a brief and very qualitative description of the basic principles of pulse EPR, we discuss some of the experiments in more detail and illustrate the potential of the methods with a number of selected applications.

  4. Control of cell respiration by nitric oxide in Ataxia Telangiectasia lymphoblastoid cells.

    PubMed

    Masci, Alessandra; Mastronicola, Daniela; Arese, Marzia; Piane, Maria; De Amicis, Andrea; Blanck, Thomas J J; Chessa, Luciana; Sarti, Paolo

    2008-01-01

    Ataxia Telangiectasia (AT) patients are particularly sensitive to oxidative-nitrosative stress. Nitric oxide (NO) controls mitochondrial respiration via the reversible inhibition of complex IV. The mitochondrial response to NO of AT lymphoblastoid cells was investigated. Cells isolated from three patients and three intrafamilial healthy controls were selected showing within each group a normal diploid karyotype and homogeneous telomere length. Different complex IV NO-inhibition patterns were induced by varying the electron flux through the respiratory chain, using exogenous cell membrane permeable electron donors. Under conditions of high electron flux the mitochondrial NO inhibition of respiration was greater in AT than in control cells (P< or =0.05). This property appears peculiar to AT, and correlates well to the higher concentration of cytochrome c detected in the AT cells. This finding is discussed on the basis of the proposed mechanism of reaction of NO with complex IV. It is suggested that the peculiar response of AT mitochondria to NO stress may be relevant to the mitochondrial metabolism of AT patients.

  5. Experimental studies of fundamental issues in electron transfer through nanometer scale devices

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hiromichi

    Electron transfer reactions constitute many of the primary events in materials science, chemistry, physics, and biochemistry, e.g. the electron transport properties and photoexcited processes in solids and molecules, chemical reactions, corrosion, photosynthesis, respiration, and so forth. A self-assembled monolayer (SAM) film provides us with a unique environment not only to understand and manipulate the surface electronic properties of a solid, but also to control electron transfer processes at the interface. The first topic in this thesis describes the structure and electron tunneling characterization of alkanethiol SAMs on InP(100). Angle-resolved X-ray photoelectron spectroscopy was used to characterize the bonding of alkanethiols to n-InP surfaces and to measure the monolayer thickness. The results showed that the sulfur binds to In atoms on the surface, and provided film thicknesses of 6.4 A for C8H17SH, 11.1 A for C12H25SH, and 14.9 A for C16H 33SH, resulting in an average tilt angle of 55°. The analysis indicated that super-exchange coupling between the alkane chains plays an important role in defining electron tunneling barriers, especially for highly tilted chains. The second topic describes studies of cytochrome c bound to pure and mixed SAMs of o-terminated alkanethiol (terminated with pyridine, imidazole or nitrile groups) and alkanethiol on gold. Electrochemical methods are used to determine electron transfer rate constants of cytochrome c, and scanning tunneling microscopy to observe the cytochrome c on the SAM. Detailed analysis revealed direct association of the heme of cytochrome c with the terminal groups of the SAMs and a 'turning-over' of the electron transfer of cytochrome c from adiabatic to non-adiabatic regime. The third topic describes studies of oxidation and reduction of cytochrome c in solution through eleven different self-assembled monolayers (SAMs) on gold electrodes by cyclic voltammetry. Electron transfer rate constants of cytochrome c through the eleven SAMs ranged from ≤10-4 to ˜10-1 cm/sec. A strong correlation between the electron transfer rate constants and the hydrogen bonding ability of the SAM is identified. This correlation is discussed in terms of the dependence of the rate constant on the outer-sphere reorganization energy and the electronic coupling between the cytochrome and the differently terminated monolayer films.

  6. Excited level populations and excitation kinetics of nonequilibrium ionizing argon discharge plasma of atmospheric pressure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Akatsuka, Hiroshi

    2009-04-15

    Population densities of excited states of argon atoms are theoretically examined for ionizing argon plasma in a state of nonequilibrium under atmospheric pressure from the viewpoint of elementary processes with collisional radiative model. The dependence of excited state populations on the electron and gas temperatures is discussed. Two electron density regimes are found, which are distinguished by the population and depopulation mechanisms for the excited states in problem. When the electron impact excitation frequency for the population or depopulation is lower than the atomic impact one, the electron density of the plasma is considered as low to estimate the populationmore » and depopulation processes. Some remarkable characteristics of population and depopulation mechanisms are found for the low electron density atmospheric plasma, where thermal relaxation by atomic collisions becomes the predominant process within the group of close-energy states in the ionizing plasma of atmospheric pressure, and the excitation temperature is almost the same as the gas temperature. In addition to the collisional relaxation by argon atoms, electron impact excitation from the ground state is also an essential population mechanism. The ratios of population density of the levels pairs, between which exists a large energy gap, include information on the electron collisional kinetics. For high electron density, the effect of atomic collisional relaxation becomes weak. For this case, the excitation mechanism is explained as electron impact ladderlike excitation similar to low-pressure ionizing plasma, since the electron collision becomes the dominant process for the population and depopulation kinetics.« less

  7. Pediatrician Knowledge, Attitudes, and Practice Related to Electronic Cigarettes.

    PubMed

    Gorzkowski, Julie A; Whitmore, Regina M; Kaseeska, Kristen R; Brishke, Janet K; Klein, Jonathan D

    2016-07-01

    Electronic cigarettes (e-cigarettes) have grown rapidly in popularity, creating concerns for pediatricians and families. Evaluating pediatricians' understanding of e-cigarettes is an important first step in effectively addressing these products in practice. This qualitative study assesses pediatricians' knowledge, attitudes, and current clinical practices related to e-cigarettes. We conducted six focus groups with 37 pediatric clinicians in 2014. Groups were led by a trained facilitator using a semistructured discussion guide. Responses were recorded, transcribed, and coded to identify relevant themes. Pediatricians know that e-cigarettes generally contain nicotine and that adolescents and young adults are most likely to use them. However, most feel uninformed about the health effects of e-cigarettes and report wanting scientific evidence for safety or harm from credible sources. Pediatricians are skeptical of claims that e-cigarettes are safe, either for users or for those exposed to second-hand e-cigarette vapor or emissions. Participants noted that clinical conversations about e-cigarettes were rare, citing barriers including a lack of systematic screening, competing priorities during clinical visits, and, for some, limited confidence in their ability to address e-cigarettes during clinical encounters. No participants recommended e-cigarettes for cessation. Pediatricians feel poorly informed about e-cigarettes and are concerned about their potential health effects. While clinical discussions about e-cigarettes are rare, recent increases in their use leaves many clinicians wanting guidance about what to say to patients and families. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  8. Electronic and postal reminders for improving immunisation coverage in children: protocol for a systematic review and meta-analysis.

    PubMed

    Chachou, Martel J; Mukinda, Fidele K; Motaze, Villyen; Wiysonge, Charles S

    2015-10-15

    Worldwide, suboptimal immunisation coverage causes the deaths of more than one million children under five from vaccine-preventable diseases every year. Reasons for suboptimal coverage are multifactorial, and a combination of interventions is needed to improve compliance with immunisation schedules. One intervention relies on reminders, where the health system prompts caregivers to attend immunisation appointments on time or re-engages caregivers who have defaulted on scheduled appointments. We undertake this systematic review to investigate the potential of reminders using emails, phone calls, social media, letters or postcards to improve immunisation coverage in children under five. We will search for published and unpublished randomised controlled trials and non-randomised controlled trials in PubMed, Scopus, CINAHL, CENTRAL, Science Citation Index, WHOLIS, Clinicaltrials.gov and the WHO International Clinical Trials Platform. We will conduct screening of search results, study selection, data extraction and risk-of-bias assessment in duplicate, resolving disagreements by consensus. In addition, we will pool data from clinically homogeneous studies using random-effects meta-analysis; assess heterogeneity of effects using the χ(2) test of homogeneity; and quantify any observed heterogeneity using the I(2) statistic. This protocol does not need approval by an ethics committee because we will use publicly available data, without directly involving human participants. The results will provide updated evidence on the effects of electronic and postal reminders on immunisation coverage, and we will discuss the applicability of the findings to low and middle-income countries. We plan to disseminate review findings through publication in a peer-reviewed journal and presentation at relevant conferences. In addition, we will prepare a policymaker-friendly summary using a validated format (eg, SUPPORT Summary) and disseminate this through social media and email discussion groups. PROSPERO registration number CRD42014012888. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Asymptotically Free Gauge Theories. I

    DOE R&D Accomplishments Database

    Wilczek, Frank; Gross, David J.

    1973-07-01

    Asymptotically free gauge theories of the strong interactions are constructed and analyzed. The reasons for doing this are recounted, including a review of renormalization group techniques and their application to scaling phenomena. The renormalization group equations are derived for Yang-Mills theories. The parameters that enter into the equations are calculated to lowest order and it is shown that these theories are asymptotically free. More specifically the effective coupling constant, which determines the ultraviolet behavior of the theory, vanishes for large space-like momenta. Fermions are incorporated and the construction of realistic models is discussed. We propose that the strong interactions be mediated by a "color" gauge group which commutes with SU(3)xSU(3). The problem of symmetry breaking is discussed. It appears likely that this would have a dynamical origin. It is suggested that the gauge symmetry might not be broken, and that the severe infrared singularities prevent the occurrence of non-color singlet physical states. The deep inelastic structure functions, as well as the electron position total annihilation cross section are analyzed. Scaling obtains up to calculable logarithmic corrections, and the naive lightcone or parton model results follow. The problems of incorporating scalar mesons and breaking the symmetry by the Higgs mechanism are explained in detail.

  10. Radical O-O coupling reaction in diferrate-mediated water oxidation studied using multireference wave function theory.

    PubMed

    Kurashige, Yuki; Saitow, Masaaki; Chalupský, Jakub; Yanai, Takeshi

    2014-06-28

    The O-O (oxygen-oxygen) bond formation is widely recognized as a key step of the catalytic reaction of dioxygen evolution from water. Recently, the water oxidation catalyzed by potassium ferrate (K2FeO4) was investigated on the basis of experimental kinetic isotope effect analysis assisted by density functional calculations, revealing the intramolecular oxo-coupling mechanism within a di-iron(vi) intermediate, or diferrate [Sarma et al., J. Am. Chem. Soc., 2012, 134, 15371]. Here, we report a detailed examination of this diferrate-mediated O-O bond formation using scalable multireference electronic structure theory. High-dimensional correlated many-electron wave functions beyond the one-electron picture were computed using the ab initio density matrix renormalization group (DMRG) method along the O-O bond formation pathway. The necessity of using large active space arises from the description of complex electronic interactions and varying redox states both associated with two-center antiferromagnetic multivalent iron-oxo coupling. Dynamic correlation effects on top of the active space DMRG wave functions were additively accounted for by complete active space second-order perturbation (CASPT2) and multireference configuration interaction (MRCI) based methods, which were recently introduced by our group. These multireference methods were capable of handling the double shell effects in the extended active space treatment. The calculations with an active space of 36 electrons in 32 orbitals, which is far over conventional limitation, provide a quantitatively reliable prediction of potential energy profiles and confirmed the viability of the direct oxo coupling. The bonding nature of Fe-O and dual bonding character of O-O are discussed using natural orbitals.

  11. Concepts for the material development of phosphorescent organic materials processable from solution and their application in OLEDs

    NASA Astrophysics Data System (ADS)

    Janietz, S.; Krueger, H.; Thesen, M.; Salert, B.; Wedel, A.

    2014-10-01

    One example of organic electronics is the application of polymer based light emitting devices (PLEDs). PLEDs are very attractive for large area and fine-pixel displays, lighting and signage. The polymers are more amenable to solution processing by printing techniques which are favourable for low cost production in large areas. With phosphorescent emitters like Ir-complexes higher quantum efficiencies were obtained than with fluorescent systems, especially if multilayer stack systems with separated charge transport and emitting layers were applied in the case of small molecules. Polymers exhibit the ability to integrate all the active components like the hole-, electron-transport and phosphorescent molecules in only one layer. Here, the active components of a phosphorescent system - triplet emitter, hole- and electron transport molecules - can be linked as a side group to a polystyrene main chain. By varying the molecular structures of the side groups as well as the composition of the side chains with respect to the triplet emitter, hole- and electron transport structure, and by blending with suitable glass-forming, so-called small molecules, brightness, efficiency and lifetime of the produced OLEDs can be optimized. By choosing the triplet emitter, such as iridium complexes, different emission colors can be specially set. Different substituted triazine molecules were introduced as side chain into a polystyrene backbone and applied as electron transport material in PLED blend systems. The influence of alkyl chain lengths of the performance will be discussed. For an optimized blend system with a green emitting phosphorescent Ir-complex efficiencies of 60 cd/A and an lifetime improvement of 66.000 h @ 1000 cd/m2 were achieved.

  12. Hybrid nanocomposites of CdSe nanocrystals distributed in complexing thiophene-based copolymers.

    PubMed

    Aldakov, Dmitry; Jiu, Tonggang; Zagorska, Malgorzata; de Bettignies, Rémi; Jouneau, Pierre-Henri; Pron, Adam; Chandezon, Frédéric

    2010-07-21

    Two types of conjugated polymers were prepared with the goal to blend them with rod-like CdSe nanocrystals. The polymers of the first type were synthesized through copolymerization of 3-octylthiophene and 3-methylene-ethylcarboxylate-thiophene to give polythiophene with solubilizing alkyl groups and methylene ester functional groups (PE series). Post-polymerization hydrolysis of the ester type polymers yielded acid-type ones (PA series). Photoluminescence (PL) quenching in these polymers induced by their titration with nanocrystals solution was chosen as a measure of the polymer-nanocrystal interactions. PL of polyacids turned out to be more efficiently quenched as compared to the case of polymers with ester groups which was interpreted as an indication of better electronic communication between the hybrid components. Infrared (IR) spectroscopy confirmed efficient coordination of the carboxylic groups to CdSe. Voltammetric studies combined with UV-vis spectroelectrochemistry enabled the determination of energy levels alignment of the molecular composite components which turned out to be of staggered type-appropriate for photovoltaic applications. The obtained blends of polyacids with CdSe nanocrystals, when studied by transmission electron microscopy (TEM), revealed the presence of an interpenetrating network in which nanorods were homogeneously distributed within the polymer matrix without any indication of agglomerates formation both on the film surface and in the cross-section. Blends with polymers containing ester groups were less homogeneous which could be explained by weaker polymer-nanocrystals interactions. Photovoltaic cells based on these hybrid materials are also discussed.

  13. Getting started with electronic mail.

    PubMed Central

    Van Vuren, D D; Johnson, D E

    1985-01-01

    This paper gives suggestions to librarians on how to get started with electronic mail. It discusses the cost- and time-saving advantages of using electronic mail rather than TWX, United States mail, or telephones for communicating ILL requests and messages. For instance, preliminary cost data show that electronic mail is often half as expensive as TWX and costs no more than a 22 stamp. Key management concerns that must be considered when setting up electronic mail are discussed, including the need for subscribers to agree on one system. Also covered are the types of equipment that can be used with electronic mail, including print terminals. PMID:4027444

  14. Utilzing Networked Computer Workstations To Conduct Electronic Focus Groups.

    ERIC Educational Resources Information Center

    Lowery, Catherine; Franklin, Kathy K.

    Researchers at the University of Arkansas at Little Rock conducted a study of faculty attitudes about the use of technology in the college classroom using electronic focus group sessions. This paper examines the electronic focus group data collection procedure. The electronic sessions were conducted in a decision-support center on campus with 13…

  15. X.400: The Standard for Message Handling Systems.

    ERIC Educational Resources Information Center

    Swain, Leigh; Tallim, Paula

    1990-01-01

    Profiles X.400, the Open Systems Interconnection (OSI) Application layer standard that supports interpersonal electronic mail services, facsimile transfer, electronic data interchange, electronic funds transfer, electronic publishing, and electronic invoicing. Also discussed are an electronic directory to support message handling, compatibility…

  16. Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part I. Electronic brachytherapy source

    PubMed Central

    Fulkerson, Regina K.; Micka, John A.; DeWerd, Larry A.

    2014-01-01

    Purpose: Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR) 192Ir sources, as well as electronic brachytherapy sources. Part I of this paper will discuss the applicators used with electronic brachytherapy sources; Part II will discuss those used with HDR 192Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics including depth dose and surface dose distributions have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. Existing dosimetry protocols available from the AAPM bookend the cross-over characteristics of a traditional brachytherapy source (as described by Task Group 43) being implemented as a low-energy superficial x-ray beam (as described by Task Group 61) as observed with the surface applicators of interest. Methods: This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and 192Ir sources (Part II). Air-kerma rate measurements for the electronic brachytherapy sources were completed with an Attix Free-Air Chamber, as well as several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose measurements of the surface dose distributions and characteristic depth dose curves were completed in-phantom. Results: Theoretical dose distributions and depth dose curves were generated for each applicator and agreed well with the measured values. A method of output verification was created that allows users to determine the applicator-specific dose to water at the treatment surface based on a measured air-kerma rate. Conclusions: The novel output verification methods described in this work will reduce uncertainties in dose delivery for treatments with these kinds of surface applicators, ultimately improving patient care. PMID:24506635

  17. Nanoribbons: From fundamentals to state-of-the-art applications

    NASA Astrophysics Data System (ADS)

    Yagmurcukardes, M.; Peeters, F. M.; Senger, R. T.; Sahin, H.

    2016-12-01

    Atomically thin nanoribbons (NRs) have been at the forefront of materials science and nanoelectronics in recent years. State-of-the-art research on nanoscale materials has revealed that electronic, magnetic, phononic, and optical properties may differ dramatically when their one-dimensional forms are synthesized. The present article aims to review the recent advances in synthesis techniques and theoretical studies on NRs. The structure of the review is organized as follows: After a brief introduction to low dimensional materials, we review different experimental techniques for the synthesis of graphene nanoribbons (GNRs) with their advantages and disadvantages. In addition, theoretical investigations on width and edge-shape-dependent electronic and magnetic properties, functionalization effects, and quantum transport properties of GNRs are reviewed. We then devote time to the NRs of the transition metal dichalcogenides (TMDs) family. First, various synthesis techniques, E-field-tunable electronic and magnetic properties, and edge-dependent thermoelectric performance of NRs of MoS2 and WS2 are discussed. Then, strongly anisotropic properties, growth-dependent morphology, and the weakly width-dependent bandgap of ReS2 NRs are summarized. Next we discuss TMDs having a T-phase morphology such as TiSe2 and stable single layer NRs of mono-chalcogenides. Strong edge-type dependence on characteristics of GaS NRs, width-dependent Seebeck coefficient of SnSe NRs, and experimental analysis on the stability of ZnSe NRs are reviewed. We then focus on the most recently emerging NRs belonging to the class of transition metal trichalcogenides which provide ultra-high electron mobility and highly anisotropic quasi-1D properties. In addition, width-, edge-shape-, and functionalization-dependent electronic and mechanical properties of blackphosphorus, a monoatomic anisotropic material, and studies on NRs of group IV elements (silicene, germanene, and stanene) are reviewed. Observation of substrate-independent quantum well states, edge and width dependent properties, the topological phase of silicene NRs are reviewed. In addition, H2 concentration-dependent transport properties and anisotropic dielectric function of GeNRs and electric field and strain sensitive I-V characteristics of SnNRs are reviewed. We review both experimental and theoretical studies on the NRs of group III-V compounds. While defect and N-termination dependent conductance are highlighted for boron nitride NRs, aluminum nitride NRs are of importance due to their dangling bond, electric field, and strain dependent electronic and magnetic properties. Finally, superlattice structure of NRs of GaN/AlN, Si/Ge, G/BN, and MoS2/WS2 is reviewed.

  18. Spiers Memorial Lecture. Molecular mechanics and molecular electronics.

    PubMed

    Beckman, Robert; Beverly, Kris; Boukai, Akram; Bunimovich, Yuri; Choi, Jang Wook; DeIonno, Erica; Green, Johnny; Johnston-Halperin, Ezekiel; Luo, Yi; Sheriff, Bonnie; Stoddart, Fraser; Heath, James R

    2006-01-01

    We describe our research into building integrated molecular electronics circuitry for a diverse set of functions, and with a focus on the fundamental scientific issues that surround this project. In particular, we discuss experiments aimed at understanding the function of bistable rotaxane molecular electronic switches by correlating the switching kinetics and ground state thermodynamic properties of those switches in various environments, ranging from the solution phase to a Langmuir monolayer of the switching molecules sandwiched between two electrodes. We discuss various devices, low bit-density memory circuits, and ultra-high density memory circuits that utilize the electrochemical switching characteristics of these molecules in conjunction with novel patterning methods. We also discuss interconnect schemes that are capable of bridging the micrometre to submicrometre length scales of conventional patterning approaches to the near-molecular length scales of the ultra-dense memory circuits. Finally, we discuss some of the challenges associated with fabricated ultra-dense molecular electronic integrated circuits.

  19. Reactivity of seventeen- and nineteen-valence electron complexes in organometallic chemistry

    NASA Technical Reports Server (NTRS)

    Stiegman, Albert E.; Tyler, David R.

    1986-01-01

    A guideline to the reactivity of 17- and 19-valence electron species in organometallic chemistry is proposed which the authors believe will supersede all others. The thesis holds that the reactions of 17-electron metal radicals are associatively activated with reactions proceeding through a 19-valence electron species. The disparate reaction chemistry of the 17-electron metal radicals are unified in terms of this associative reaction pathway, and the intermediacy of 19-valence electron complexes in producing the observed products is discussed. It is suggested that related associatively activated pathways need to be considered in some reactions that are thought to occur by more conventional routes involving 16- and 18-electron intermediates. The basic reaction chemistry and electronic structures of these species are briefly discussed.

  20. Interacting Electrons and Holes in Quasi-2D Quantum Dots in Strong Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Hawrylak, P.; Sheng, W.; Cheng, S.-J.

    2004-09-01

    Theory of optical properties of interacting electrons and holes in quasi-2D quantum dots in strong magnetic fields is discussed. In two dimensions and the lowest Landau level, hidden symmetries control the interaction of the interacting system with light. By confining electrons and holes into quantum dots hidden symmetries can be removed and the excitation spectrum of electrons and excitons can be observed. We discuss a theory electronic and of excitonic quantum Hall droplets at a filling factorν=2. For an excitonic quantum Hall droplet the characteristic emission spectra are predicted to be related to the total spin of electron and hole configurations. For the electronic droplet the excitation spectrum of the droplet can be mapped out by measuring the emission for increasing number of electrons.

  1. NASA and COTS Electronics: Past Approach and Successes - Future Considerations

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.

    2018-01-01

    NASA has a long history of using commercial grade electronics in space. In this talk, a brief history of NASAâ's trends and approaches to commercial grade electronics focusing on processing and memory systems will be presented. This will include providing summary information on the space hazards to electronics as well as NASA mission trade space. We will also discuss developing recommendations for risk management approaches to Electrical, Electronic and Electromechanical (EEE) parts and reliability in space. The final portion of the talk will discuss emerging aerospace trends and the future for Commercial Off The Shelf (COTS) usage.

  2. Barriers to computed tomography radiation risk communication in the emergency department: a qualitative analysis of patient and physician perspectives.

    PubMed

    Robey, Thomas E; Edwards, Kelly; Murphy, Mary K

    2014-02-01

    This qualitative study aimed to characterize the barriers to informed discussions between patients and emergency physicians (EPs) about radiation risk from computed tomography (CT) and to identify future interventions to improve patient understanding of CT radiation risk. This study used a focus group approach to collect concepts about radiation risk exposure from a national sample of EPs and a local sample of emergency department (ED) patients. A directed content analysis used an a priori medical ethics framework to explore themes from the focus groups while a subsequent normative ethics analysis compared these results with existing perceptions about discussing CT radiation risk. Focus groups (three each for a total of 19 EPs and 27 patients) identified concepts consistent with core medical ethics principles: patients emphasized autonomy and nonmaleficence more than physicians, while physicians emphasized beneficence. Subjects' knowledge of radiation dose and risk were equivalent to previously published reports. When asked about whether they should talk about radiation with patients, 74% of EPs reported that radiation exposure should be discussed, but the study EPs self-reported doing so with only an average of 24% of patients. Patients reported wanting to hear about radiation from their physicians the next time they need CT scans and thought that a written handout would work better than any other method. When presented with options for how to discuss risk with patients, EPs reported needing easy access to risk information and preferred discussion over other communications approaches, but had mixed support of distributing patient handouts. The normative view that radiation from diagnostic CT should be discussed in the ED is shared by patients and physicians, but is challenged by the lack of a structured method to communicate CT radiation risk to ED patients. Our analysis identifies promising interest among physicians and patients to use information guides and electronic order prompts as potential informational tools to overcome this barrier. © 2014 by the Society for Academic Emergency Medicine.

  3. Three dimensional particle-in-cell simulations of electron beams created via reflection of intense laser light from a water target

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ngirmang, Gregory K., E-mail: ngirmang.1@osu.edu; Orban, Chris; Feister, Scott

    We present 3D Particle-in-Cell (PIC) modeling of an ultra-intense laser experiment by the Extreme Light group at the Air Force Research Laboratory using the Large Scale Plasma (LSP) PIC code. This is the first time PIC simulations have been performed in 3D for this experiment which involves an ultra-intense, short-pulse (30 fs) laser interacting with a water jet target at normal incidence. The laser-energy-to-ejected-electron-energy conversion efficiency observed in 2D(3v) simulations were comparable to the conversion efficiencies seen in the 3D simulations, but the angular distribution of ejected electrons in the 2D(3v) simulations displayed interesting differences with the 3D simulations' angular distribution;more » the observed differences between the 2D(3v) and 3D simulations were more noticeable for the simulations with higher intensity laser pulses. An analytic plane-wave model is discussed which provides some explanation for the angular distribution and energies of ejected electrons in the 2D(3v) simulations. We also performed a 3D simulation with circularly polarized light and found a significantly higher conversion efficiency and peak electron energy, which is promising for future experiments.« less

  4. Face-to-face or face-to-screen? Undergraduates' opinions and test performance in classroom vs. online learning

    PubMed Central

    Kemp, Nenagh; Grieve, Rachel

    2014-01-01

    As electronic communication becomes increasingly common, and as students juggle study, work, and family life, many universities are offering their students more flexible learning opportunities. Classes once delivered face-to-face are often replaced by online activities and discussions. However, there is little research comparing students' experience and learning in these two modalities. The aim of this study was to compare undergraduates' preference for, and academic performance on, class material and assessment presented online vs. in traditional classrooms. Psychology students (N = 67) at an Australian university completed written exercises, a class discussion, and a written test on two academic topics. The activities for one topic were conducted face-to-face, and the other online, with topics counterbalanced across two groups. The results showed that students preferred to complete activities face-to-face rather than online, but there was no significant difference in their test performance in the two modalities. In their written responses, students expressed a strong preference for class discussions to be conducted face-to-face, reporting that they felt more engaged, and received more immediate feedback, than in online discussion. A follow-up study with a separate group (N = 37) confirmed that although students appreciated the convenience of completing written activities online in their own time, they also strongly preferred to discuss course content with peers in the classroom rather than online. It is concluded that online and face-to-face activities can lead to similar levels of academic performance, but that students would rather do written activities online but engage in discussion in person. Course developers could aim to structure classes so that students can benefit from both the flexibility of online learning, and the greater engagement experienced in face-to-face discussion. PMID:25429276

  5. Face-to-face or face-to-screen? Undergraduates' opinions and test performance in classroom vs. online learning.

    PubMed

    Kemp, Nenagh; Grieve, Rachel

    2014-01-01

    As electronic communication becomes increasingly common, and as students juggle study, work, and family life, many universities are offering their students more flexible learning opportunities. Classes once delivered face-to-face are often replaced by online activities and discussions. However, there is little research comparing students' experience and learning in these two modalities. The aim of this study was to compare undergraduates' preference for, and academic performance on, class material and assessment presented online vs. in traditional classrooms. Psychology students (N = 67) at an Australian university completed written exercises, a class discussion, and a written test on two academic topics. The activities for one topic were conducted face-to-face, and the other online, with topics counterbalanced across two groups. The results showed that students preferred to complete activities face-to-face rather than online, but there was no significant difference in their test performance in the two modalities. In their written responses, students expressed a strong preference for class discussions to be conducted face-to-face, reporting that they felt more engaged, and received more immediate feedback, than in online discussion. A follow-up study with a separate group (N = 37) confirmed that although students appreciated the convenience of completing written activities online in their own time, they also strongly preferred to discuss course content with peers in the classroom rather than online. It is concluded that online and face-to-face activities can lead to similar levels of academic performance, but that students would rather do written activities online but engage in discussion in person. Course developers could aim to structure classes so that students can benefit from both the flexibility of online learning, and the greater engagement experienced in face-to-face discussion.

  6. Stimulated emission and optical properties of pyranyliden fragment containing compounds in PVK matrix

    NASA Astrophysics Data System (ADS)

    Vembris, Aivars; Zarins, Elmars; Kokars, Valdis

    2017-10-01

    Organic solid state lasers are thoughtfully investigated due to their potential applications in communication, sensors, biomedicine, etc. Low amplified spontaneous emission (ASE) excitation threshold value is essential for further use of the material in devices. Intramolecular interaction limits high molecule density load in the matrix. It is the case of the well-known red light emitting laser dye - 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM). The lowest ASE threshold value of the mentioned laser dye could be obtained within the concentration range between 2 and 4 wt%. At higher concentration threshold energy drastically increases. In this work optical and ASE properties of three original DCM derivatives in poly(N-vinylcarbazole) (PVK) at various concentrations will be discussed. One of the derivatives is modified DCM dye in which the methyl substituents in the electron donor part have been replaced with bulky trityloxyethyl groups (DWK-1). These sterically significant functional groups do not influence electron transitions in the dye but prevent aggregation of the molecules. The chemical structure of the second investigated compound is similar to DWK-1 where the methyl group is replaced with the tert-butyl substituent (DWK-1TB). The third derivative (DWK-2) consists of two N,N-di(trityloxyethyl)amino electron donor groups. All results were compared with DCM:PVK system. Photoluminescence quantum yield (PLQY) is up to ten times larger for DWK-1TB with respect to DCM systems. Bulky trityloxyethyl groups prevent aggregation of the molecules thus decreasing interaction between dyes and amount of non-radiative decays. The red shift of the photoluminescence and amplified spontaneous emission at higher concentrations were observed due to the solid state solvation effect. The increase of the investigated dye density in the matrix with a smaller reduction in PLQY resulted in low ASE threshold energy. The lowest threshold value was obtained around 21 μJ/cm2 (2.1 kW/cm2) in DWK-1TB:PVK films.

  7. A qualitative assessment of the perceived risks of electronic cigarette and hookah use in pregnancy.

    PubMed

    Kahr, Maike K; Padgett, Shannon; Shope, Cindy D; Griffin, Emily N; Xie, Susan S; Gonzalez, Pablo J; Levison, Judy; Mastrobattista, Joan; Abramovici, Adi R; Northrup, Thomas F; Stotts, Angela L; Aagaard, Kjersti M; Suter, Melissa A

    2015-12-21

    Studies reveal that electronic cigarette (e-cigarette) and hookah use are increasing among adolescents and young adults. However, the long-term health effects are unknown, especially with regards to pregnancy. Because of the increased use in women of reproductive age, and the unknown long-term health risks, our primary objectives were to determine the perceived risks of e-cigarette and hookah use in pregnancy, and learn common colloquial terms associated with e-cigarettes. Furthermore, we sought to determine if there is a stigma associated with e-cigarette use in pregnancy. Eleven focus groups including 87 participants were conducted immediately following regularly scheduled CenteringPregnancy® prenatal care with women at three different clinics in the greater Houston area. A minimum of two facilitators led the groups, using ten lead-in prompts, with Spanish translation as necessary. Facilitators took notes which were compared immediately following each group discussion and each group was audio recorded and transcribed. Three facilitators utilized NVivo 9.0 software to organize the transcribed data into nodes to identify major themes. To increase rigor, transcripts were further analyzed by two obstetricians who were instructed to find the major themes. Analyses revealed contradicting themes concerning e-cigarette use. In general, e-cigarettes were perceived as safer alternatives to regular tobacco cigarettes, especially if used as smoking cessation devices. A major theme is that use in pregnancy is harmful to the fetus. However, it was perceived that use for smoking cessation in pregnancy may have fewer side effects. We found that a common term for e-cigarettes is "Blu." In our discussion of hookah use, participants perceived use as popular among teenagers and that use in pregnancy is dangerous for the fetus. Although a strong theme emerged against hookah use, we found contradicting themes in our discussions on e-cigarette use in pregnancy. It is possible that e-cigarette use will not carry the same stigma as regular cigarette smoking in pregnancy. In addition, the impression of e-cigarettes as a healthier alternative to smoking may influence use in pregnancy. Clinicians need to be prepared for questions of e-cigarette safety and efficacy as smoking cessation devices from their pregnant patients who smoke, and women who smoke and are planning to become pregnant.

  8. Dispersive charge transport due to strong charge dipole interactions of cyano-group in the cyano-carbazole based molecular glass

    NASA Astrophysics Data System (ADS)

    Oh, Dong Keun; Hong, Sung Mok; Lee, Cheol Eui; Kim, B.-S.; Jin, J.-I.

    2005-12-01

    Using the time of flight (ToF) method, we investigated the bipolar charge transport for two glass-forming molecules containing carbazole and cyano-carbazole moiety. The enhanced electron mobility was observed in the cyano-carbazole compound. From the numerical method based the Laplace formalism, the distribution of hole trapping energy was obtained for the carbazole compound. This result was compared with the exponential distribution extracted from dispersion parameter for the cyano-carbazole material. Considering charge-dipole interactions as a reason for the disordered trapping mechanism, we discussed dispersive charge transport induced by a strong dipolar (i.e. cyano) group by comparing the distributions of hole trapping sites for two compounds.

  9. Textbooks on tap: using electronic books housed in handheld devices in nursing clinical courses.

    PubMed

    Williams, Margaret G; Dittmer, Arlis

    2009-01-01

    Changing technology is creating new ways to approach nursing education and practice. Beginning in 2003, using a quasi-experimental design, this project introduced personal digital assistants (PDAs) as a clinical tool to five experimental and control groups of students and faculty. The handheld device, or PDA, was loaded with e-books for clinical practice. Differences in learning styles and preferences emerged during the different phases of the study. Students were quickly able to master the technology and use the device effectively, reporting that they liked the concise nature of the information obtained. No students expressed dissatisfaction or regret at being in the experimental group. Results and implications for clinical practice, education, and library resources are discussed.

  10. (Tl, Sb) and (Tl, Bi) binary surface reconstructions on Ge(111) substrate

    NASA Astrophysics Data System (ADS)

    Gruznev, D. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Yakovlev, A. A.; Mihalyuk, A. N.; Zotov, A. V.; Saranin, A. A.

    2018-03-01

    2D compounds made of Group-III and Group-V elements on the surface of silicon and germanium attract considerable attention due to prospects of creating III-V binary monolayers, which are predicted to hold advanced physical properties. In the present work, we have investigated two such systems, (Tl, Sb)/Ge(111) and (Tl, Bi)/Ge(111) using scanning tunneling microscopy, low energy electron diffraction observations and density-functional-theory calculations. In addition to the previously reported surface structures of 2D (Tl, Sb) and (Tl, Bi) compounds on Si(111), we found new ones, namely, √{ 7} × √{ 7} and 3 × 3. Formation processes and plausible models of their atomic arrangements are discussed.

  11. Determination of ground and excited state dipole moments via electronic Stark spectroscopy: 5-methoxyindole

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilke, Josefin; Wilke, Martin; Schmitt, Michael, E-mail: mschmitt@uni-duesseldorf.de

    2016-01-28

    The dipole moments of the ground and lowest electronically excited singlet state of 5-methoxyindole have been determined by means of optical Stark spectroscopy in a molecular beam. The resulting spectra arise from a superposition of different field configurations, one with the static electric field almost parallel to the polarization of the exciting laser radiation, the other nearly perpendicular. Each field configuration leads to different intensities in the rovibronic spectrum. With an automated evolutionary algorithm approach, the spectra can be fit and the ratio of both field configurations can be determined. A simultaneous fit of two spectra with both field configurationsmore » improved the precision of the dipole moment determination by a factor of two. We find a reduction of the absolute dipole moment from 1.59(3) D to 1.14(6) D upon electronic excitation to the lowest electronically excited singlet state. At the same time, the dipole moment orientation rotates by 54{sup ∘} showing the importance of the determination of the dipole moment components. The dipole moment in the electronic ground state can approximately be obtained from a vector addition of the indole and the methoxy group dipole moments. However, in the electronically excited state, vector addition completely fails to describe the observed dipole moment. Several reasons for this behavior are discussed.« less

  12. Where does the electron go? The nature of ortho/para and meta group directing in electrophilic aromatic substitution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Shubin, E-mail: shubin@email.unc.edu

    Electrophilic aromatic substitution as one of the most fundamental chemical processes is affected by atoms or groups already attached to the aromatic ring. The groups that promote substitution at the ortho/para or meta positions are, respectively, called ortho/para and meta directing groups, which are often characterized by their capability to donate electrons to or withdraw electrons from the ring. Though resonance and inductive effects have been employed in textbooks to explain this phenomenon, no satisfactory quantitative interpretation is available in the literature. Here, based on the theoretical framework we recently established in density functional reactivity theory (DFRT), where electrophilicity andmore » nucleophilicity are simultaneously quantified by the Hirshfeld charge, the nature of ortho/para and meta group directing is systematically investigated for a total of 85 systems. We find that regioselectivity of electrophilic attacks is determined by the Hirshfeld charge distribution on the aromatic ring. Ortho/para directing groups have most negative charges on the ortho/para positions, while meta directing groups often possess the largest negative charge on the meta position. Our results do not support that ortho/para directing groups are electron donors and meta directing groups are electron acceptors. Most neutral species we studied here are electron withdrawal in nature. Anionic systems are always electron donors. There are also electron donors serving as meta directing groups. We predicted ortho/para and meta group directing behaviors for a list of groups whose regioselectivity is previously unknown. In addition, strong linear correlations between the Hirshfeld charge and the highest occupied molecular orbital have been observed, providing the first link between the frontier molecular orbital theory and DFRT.« less

  13. A new species of Dianthus (Caryophyllaceae) from Antalya, South Anatolia, Turkey

    PubMed Central

    Deniz, İsmail Gökhan; Aykurt, Candan; Genç, İlker; Aksoy, Ahmet

    2016-01-01

    Abstract Dianthus multiflorus from Gazipaşa (Antalya), south Anatolia (Turkey), is described as a new annual species with verrucose calyx. The morphological differences from the species within the same group with Dianthus multiflorus, which are Dianthus aydogdui, Dianthus cyri and Dianthus tripunctatus, are discussed. The International Union for Conservation of Nature (IUCN) threat category and observations on the ecology of the populations are noted. The karyology and seed micromorphology of Dianthus multiflorus and Dianthus tripunctatus were examined by light microscopy and scanning electron microscopy. PMID:27489473

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nayak, Vikas; Verma, U. P.

    Quantum mechanical based first principle calculations have been employed to obtain the unit cell lattice parameters of mercury thiogallate (HgGa{sub 2}S{sub 4}) in defect stannite structure for the first time. For this, we treated HgGa{sub 2}S{sub 4} in two different types of site symmetries in the same space group. In both the cases obtained unit cell parameters are same, which shows the accuracy of present approach. The electronic band structures show the semiconducting behavior in both the cases. The density of states plot are also studied and discussed.

  15. Amplifiers in the radio-electronic equipment of aircraft

    NASA Astrophysics Data System (ADS)

    Khol'Nyi, Vladimir Ia.

    The applications, classification, and technical specifications of airborne electronic amplifiers are discussed. Particular attention is given to the general design and principles of operation of single amplification cascades and multicascade amplifiers, including dc, audio, and video amplifiers used as part of the radio-electronic equipment of modern aircraft. The discussion also covers the principal technical and performance characteristics of various amplifiers, their operating conditions, service, and repair.

  16. Implementation of a World Wide Web server for the oil and gas industry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blaylock, R.E.; Martin, F.D.; Emery, R.

    1995-12-31

    The Gas and Oil Technology Exchange and Communication Highway, (GO-TECH), provides an electronic information system for the petroleum community for the purpose of exchanging ideas, data, and technology. The personal computer-based system fosters communication and discussion by linking oil and gas producers with resource centers, government agencies, consulting firms, service companies, national laboratories, academic research groups, and universities throughout the world. The oil and gas producers are provided access to the GO-TECH World Wide Web home page via modem links, as well as Internet. The future GO-TECH applications will include the establishment of{open_quote}Virtual corporations {close_quotes} consisting of consortiums of smallmore » companies, consultants, and service companies linked by electronic information systems. These virtual corporations will have the resources and expertise previously found only in major corporations.« less

  17. Implementation of a World Wide Web server for the oil and gas industry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blaylock, R.E.; Martin, F.D.; Emery, R.

    1996-10-01

    The Gas and Oil Technology Exchange and Communication Highway (GO-TECH) provides an electronic information system for the petroleum community for exchanging ideas, data, and technology. The PC-based system fosters communication and discussion by linking the oil and gas producers with resource centers, government agencies, consulting firms, service companies, national laboratories, academic research groups, and universities throughout the world. The oil and gas producers can access the GO-TECH World Wide Web (WWW) home page through modem links, as well as through the Internet. Future GO-TECH applications will include the establishment of virtual corporations consisting of consortia of small companies, consultants, andmore » service companies linked by electronic information systems. These virtual corporations will have the resources and expertise previously found only in major corporations.« less

  18. From Artificial Atoms to Nanocrystal Molecules: Preparation and Properties of More Complex Nanostructures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Choi, Charina L; Alivisatos, A Paul

    2009-10-20

    Quantum dots, which have found widespread use in fields such as biomedicine, photovoltaics, and electronics, are often called artificial atoms due to their size-dependent physical properties. Here this analogy is extended to consider artificial nanocrystal molecules, formed from well-defined groupings of plasmonically or electronically coupled single nanocrystals. Just as a hydrogen molecule has properties distinct from two uncoupled hydrogen atoms, a key feature of nanocrystal molecules is that they exhibit properties altered from those of the component nanoparticles due to coupling. The nature of the coupling between nanocrystal atoms and its response to vibrations and deformations of the nanocrystal moleculemore » bonds are of particular interest. We discuss synthetic approaches, predicted and observed physical properties, and prospects and challenges toward this new class of materials.« less

  19. Early experiences with big data at an academic medical center.

    PubMed

    Halamka, John D

    2014-07-01

    Beth Israel Deaconess Medical Center (BIDMC), an academic health care institution affiliated with Harvard University, has been an early adopter of electronic applications since the 1970s. Various departments of the medical center and the physician practice groups affiliated with it have implemented electronic health records, filmless imaging, and networked medical devices to such an extent that data storage at BIDMC now amounts to three petabytes and continues to grow at a rate of 25 percent a year. Initially, the greatest technical challenge was the cost and complexity of data storage. However, today the major focus is on transforming raw data into information, knowledge, and wisdom. This article discusses the data growth, increasing importance of analytics, and changing user requirements that have shaped the management of big data at BIDMC. Project HOPE—The People-to-People Health Foundation, Inc.

  20. Studies of beam position monitor stability

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tenenbaum, P.

    1998-05-01

    The authors present the results from two studies of the time stability between the mechanical center of a beam position monitor and its electrical/electronic center. In the first study, a group of 93 BPM processors was calibrated via Test Pulse Generator once per hour in order to measure the contribution of the readout electronics to offset drifts. In the second study, a triplet of stripline BPMs in the Final Focus Test Beam, separated only by drift spaces, was read out every 6 minutes during 1 week of beam operation. In both cases offset stability was observed to be on themore » order of microns over time spans ranging from hours to days, although during the beam study much worse performance was also observed. Implications for the beam position monitor system of future linear collider systems are discussed.« less

  1. The cosmological lithium problem revisited

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bertulani, C. A., E-mail: carlos.bertulani@tamuc.edu; Department of Physics and Astronomy, Texas A&M University, College Station, TX 75429; Mukhamedzhanov, A. M., E-mail: akram@comp.tamu.edu

    After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although ourmore » attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.« less

  2. Ab initio study on the molecular recognition by metalloporphyrins: CO interaction with iron porphyrin

    NASA Astrophysics Data System (ADS)

    Han, Seungwu; Cho, Kyeongjae; Ihm, Jisoon

    1999-02-01

    We have performed ab initio pseudopotential calculations to study the effects of structural deformations of iron porphyrin on the configuration of a carbon monoxide (CO) attached to it. We have considered two proximal deformations around the heme group: (i) rotation of a pyrrole ring in the iron porphyrin, and (ii) rotation of the imidazole side chain bound to the iron atom. We have identified induced changes of the atomic geometry and the electronic structure of the iron porphyrin-CO complex, and the results elucidate the microscopic nature of the CO interaction with the iron porphyrin. Implications on the controversies over the binding angle of the CO molecule on the iron porphyrin under different circumstances are discussed. A potential application to the simulation-based chemical sensor design is also discussed.

  3. Deposition of thin Si and Ge films by ballistic hot electron reduction in a solution-dripping mode and its application to the growth of thin SiGe films

    NASA Astrophysics Data System (ADS)

    Suda, Ryutaro; Yagi, Mamiko; Kojima, Akira; Mentek, Romain; Mori, Nobuya; Shirakashi, Jun-ichi; Koshida, Nobuyoshi

    2015-04-01

    To enhance the usefulness of ballistic hot electron injection into solutions for depositing thin group-IV films, a dripping scheme is proposed. A very small amount of SiCl4 or GeCl4 solution was dripped onto the surface of a nanocrystalline Si (nc-Si) electron emitter, and then the emitter is driven without using any counter electrodes. It is shown that thin Si and Ge films are deposited onto the emitting surface. Spectroscopic surface and compositional analyses showed no extrinsic carbon contaminations in deposited thin films, in contrast to the results of a previous study using the dipping scheme. The availability of this technique for depositing thin SiGe films is also demonstrated using a mixture SiCl4+GeCl4 solution. Ballistic hot electrons injected into solutions with appropriate kinetic energies promote preferential reduction of target ions with no by-products leading to nuclei formation for the thin film growth. Specific advantageous features of this clean, room-temperature, and power-effective process is discussed in comparison with the conventional dry and wet processes.

  4. Optical properties of spray coated layers with carbon nanotubes and graphene nanoplatelets

    NASA Astrophysics Data System (ADS)

    Lorenc, Zofia; Krzeminski, Jakub; Wroblewski, Grzegorz; Salbut, Leszek

    2016-04-01

    Carbon nanotubes as well as graphene are allotropic forms of carbon. Graphene is a two dimensional (2D) form of atomic-scale, hexagonal lattice, while carbon nanotube is a cylindrical nanostructure composed of a rolled sheet of graphene lattice at specific and discrete angles. Both of discussed materials have a high potential for modern engineering, especially in organic and printed electronics. High transparency in the visible part of the electromagnetic spectrum and low electrical resistance are desirable features in various applications and may be fulfilled with studied carbon nanomaterials. They have chances to become an important technological improvement in customers electronic devices by applying them to electrodes production in flexible screens and light sources. Graphene end carbon nanotubes are conceptually similar. However, characteristic properties of these two substances are different. In the article authors present the results of the transmission in visible electromagnetic spectrum characteristics of different samples. This parameter and the resistance of electrodes are tested, analysed and compared. Characteristics of optical transmittance against resistance with the optimal point of that relationship are presented in paper. Moreover, dependency of graphene nanoplatelets agglomerates arrangement against type of nano-fillers is shown. Two groups of tested inks contain graphene nanoplatelets with different fillers diameters. The third group contains carbon nanotubes. Described parameters are important for production process and results of analysis can be used by technologists working with elastic electronics.

  5. A dipole-bound dianion

    NASA Astrophysics Data System (ADS)

    Skurski, Piotr; Simons, Jack

    2000-04-01

    The possibility of binding two electrons by the dipole potential of a molecule was examined earlier by us using model potentials. That study suggested that large dipole moments μ=qR and large charge separation distances R (or equivalently large charges q) would be required to achieve binding two electrons. For example, even with a charge q=1.5 a.u. which might be achieved using di- or tri-valent cations, a dipole moment exceeding 15.922 D is needed. The presence of inner-shell electrons even further increases the value of μ that is required because the dipole-bound electrons' orbital must be orthogonal to and excluded from such inner shells. In the present work, we discuss our efforts to find a real molecule that can actually bind two electrons to a single dipole site. Numerical results are presented for the mono- and dianions of a double 5-member carbon ring system substituted with a Ca atom and three superhalogen -PF5 groups. The dianion of this molecule is found to be geometrically stable and to have a vertical electron detachment energy of ca. 0.8 eV. Its two excess electrons occupy the same fully symmetric a1 molecular orbital localized at the electropositive Ca end of the neutral system as is routinely observed in dipole-bound monoanions. Although our final candidate is chemically unusual, it is hoped that our predictions about it will encourage others to search for more synthetically tractable alternatives.

  6. Generation of Low-Energy High-Current Electron Beams in Plasma-Anode Electron Guns

    NASA Astrophysics Data System (ADS)

    Ozur, G. E.; Proskurovsky, D. I.

    2018-01-01

    This paper is a review of studies on the generation of low-energy high-current electron beams in electron guns with a plasma anode and an explosive-emission cathode. The problems related to the initiation of explosive electron emission under plasma and the formation and transport of high-current electron beams in plasma-filled systems are discussed consecutively. Considerable attention is given to the nonstationary effects that occur in the space charge layers of plasma. Emphasis is also placed on the problem of providing a uniform energy density distribution over the beam cross section, which is of critical importance in using electron beams of this type for surface treatment of materials. Examples of facilities based on low-energy high-current electron beam sources are presented and their applications in materials science and practice are discussed.

  7. Educational Systems Design Implications of Electronic Publishing.

    ERIC Educational Resources Information Center

    Romiszowski, Alexander J.

    1994-01-01

    Discussion of electronic publishing focuses on the four main purposes of media in general: communication, entertainment, motivation, and education. Highlights include electronic journals and books; hypertext; user control; computer graphics and animation; electronic games; virtual reality; multimedia; electronic performance support;…

  8. Electronic Library: A TERI Experiment.

    ERIC Educational Resources Information Center

    Kar, Debal C.; Deb, Subrata; Kumar, Satish

    2003-01-01

    Discusses the development of Electronic Library at TERI (The Energy and Resources Institute, New Delhi). Highlights include: hardware and software used; the digital library/Virtual Electronic Library; directory of Internet journals; virtual reference resources; electronic collection/Physical Electronic Library; downloaded online full-length…

  9. Graphene-Based Flexible and Stretchable Electronics.

    PubMed

    Jang, Houk; Park, Yong Ju; Chen, Xiang; Das, Tanmoy; Kim, Min-Seok; Ahn, Jong-Hyun

    2016-06-01

    Graphene provides outstanding properties that can be integrated into various flexible and stretchable electronic devices in a conventional, scalable fashion. The mechanical, electrical, and optical properties of graphene make it an attractive candidate for applications in electronics, energy-harvesting devices, sensors, and other systems. Recent research progress on graphene-based flexible and stretchable electronics is reviewed here. The production and fabrication methods used for target device applications are first briefly discussed. Then, the various types of flexible and stretchable electronic devices that are enabled by graphene are discussed, including logic devices, energy-harvesting devices, sensors, and bioinspired devices. The results represent important steps in the development of graphene-based electronics that could find applications in the area of flexible and stretchable electronics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. High Temperature Pt/Alumina Co-Fired System for 500 C Electronic Packaging Applications

    NASA Technical Reports Server (NTRS)

    Chen, Liang-Yu; Neudeck, Philip G.; Spry, David J.; Beheim, Glenn M.; Hunter, Gary W.

    2015-01-01

    Gold thick-film metallization and 96 alumina substrate based prototype packaging system developed for 500C SiC electronics and sensors is briefly reviewed, the needs of improvement are discussed. A high temperature co-fired alumina material system based packaging system composed of 32-pin chip-level package and printed circuit board is discussed for packaging 500C SiC electronics and sensors.

  11. Understanding electron magnetic circular dichroism in a transition potential approach

    NASA Astrophysics Data System (ADS)

    Barthel, J.; Mayer, J.; Rusz, J.; Ho, P.-L.; Zhong, X. Y.; Lentzen, M.; Dunin-Borkowski, R. E.; Urban, K. W.; Brown, H. G.; Findlay, S. D.; Allen, L. J.

    2018-04-01

    This paper introduces an approach based on transition potentials for inelastic scattering to understand the underlying physics of electron magnetic circular dichroism (EMCD). The transition potentials are sufficiently localized to permit atomic-scale EMCD. Two-beam and three-beam systematic row cases are discussed in detail in terms of transition potentials for conventional transmission electron microscopy, and the basic symmetries which arise in the three-beam case are confirmed experimentally. Atomic-scale EMCD in scanning transmission electron microscopy (STEM), using both a standard STEM probe and vortex beams, is discussed.

  12. Overview of TSCA Chemical Data Reporting Requirements and e‐Reporting

    EPA Pesticide Factsheets

    The presentation included an overview of the 2012 reporting requirements, a discussion of joint reporting, a discussion of considerations related to the reporting of by-products and updated information about registering for electronic reporting and for using the electronic reporting tool.

  13. Conceptual Design of Electron-Beam Generated Plasma Tools

    NASA Astrophysics Data System (ADS)

    Agarwal, Ankur; Rauf, Shahid; Dorf, Leonid; Collins, Ken; Boris, David; Walton, Scott

    2015-09-01

    Realization of the next generation of high-density nanostructured devices is predicated on etching features with atomic layer resolution, no damage and high selectivity. High energy electron beams generate plasmas with unique features that make them attractive for applications requiring monolayer precision. In these plasmas, high energy beam electrons ionize the background gas and the resultant daughter electrons cool to low temperatures via collisions with gas molecules and lack of any accelerating fields. For example, an electron temperature of <0.6 eV with densities comparable to conventional plasma sources can be obtained in molecular gases. The chemistry in such plasmas can significantly differ from RF plasmas as the ions/radicals are produced primarily by beam electrons rather than those in the tail of a low energy distribution. In this work, we will discuss the conceptual design of an electron beam based plasma processing system. Plasma properties will be discussed for Ar, Ar/N2, and O2 plasmas using a computational plasma model, and comparisons made to experiments. The fluid plasma model is coupled to a Monte Carlo kinetic model for beam electrons which considers gas phase collisions and the effect of electric and magnetic fields on electron motion. The impact of critical operating parameters such as magnetic field, beam energy, and gas pressure on plasma characteristics in electron-beam plasma processing systems will be discussed. Partially supported by the NRL base program.

  14. Communication: Photoionization of degenerate orbitals for randomly oriented molecules: The effect of time-reversal symmetry on recoil-ion momentum angular distributions

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshi-Ichi

    2018-04-01

    The photoelectron asymmetry parameter β, which characterizes the direction of electrons ejected from a randomly oriented molecular ensemble by linearly polarized light, is investigated for degenerate orbitals. We show that β is totally symmetric under the symmetry operation of the point group of a molecule, and it has mixed properties under time reversal. Therefore, all degenerate molecular orbitals, except for the case of degeneracy due to time reversal, have the same β (Wigner-Eckart theorem). The exceptions are e-type complex orbitals of the Cn, Sn, Cnh, T, and Th point groups, and calculations on boric acid (C3h symmetry) are performed as an example. However, including those point groups, all degenerate orbitals have the same β if those orbitals are real. We discuss the implications of this operator formalism for molecular alignment and photoelectron circular dichroism.

  15. Geometry dependence of electron donating or accepting abilities of amine groups in 4,4‧-disulfanediylbis(methylene)dithiazol-2-amine: Pyramidal versus planar

    NASA Astrophysics Data System (ADS)

    Karabıyık, Hasan; Kırılmış, Cumhur; Karabıyık, Hande

    2017-08-01

    The molecular and crystal structure of the title compound in which two thiazole-2-amine rings are linked to each other by disulfide bridge (sbnd Csbnd Ssbnd Ssbnd Csbnd) were studied by single-crystal X-ray diffraction, FT-IR, NMR spectroscopy, quantum chemical calculations and topological analyses on the electron density. A novel synthesis route for the compounds having symmetrical disulfide bridge is reported. The most important result regarding the compound is about electron donating or accepting properties of the terminal amine groups. Planar amine group acts as an electron-donating group, while pyramidal amine behaves as electron-accepting group. This inference was confirmed by scrutiny of crystallographic geometry and quantum chemical studies. To ascertain underlying reasons for this fact, intermolecular interactions (Nsbnd H⋯N type H-bonds and Csbnd H···π interactions) were studied. These interactions involving aromatic thiazole rings are verified by topological electron density and Hirshfeld surface analyses. Intermolecular interactions do not have an effect on the differentiation in electron donating or accepting ability of amine groups, because both amine groups are involved in Nsbnd H⋯N type H-bonds. In methodological sense, it has been understood that Ehrenfest forces acting on electron density are useful theoretical probe to analyze intra-molecular charge transfer processes.

  16. VO{sub 2} (A): Reinvestigation of crystal structure, phase transition and crystal growth mechanisms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rao Popuri, Srinivasa; University of Bordeaux, ICMCB, UPR 9048, F-33608 Pessac; National Institute for Research and Development in Electrochemistry and Condensed Matter, Timisoara, Plautius Andronescu Str. No. 1, 300224 Timisoara

    2014-05-01

    Well crystallized VO{sub 2} (A) microrods were grown via a single step hydrothermal reaction in the presence of V{sub 2}O{sub 5} and oxalic acid. With the advantage of high crystalline samples, we propose P4/ncc as an appropriate space group at room temperature. From morphological studies, we found that the oriented attachment and layer by layer growth mechanisms are responsible for the formation of VO{sub 2} (A) micro rods. The structural and electronic transitions in VO{sub 2} (A) are strongly first order in nature, and a marked difference between the structural transition temperatures and electronic transitions temperature was evidenced. The reversiblemore » intra- (LTP-A to HTP-A) and irreversible inter- (HTP-A to VO{sub 2} (M1)) structural phase transformations were studied by in-situ powder X-ray diffraction. Attempts to increase the size of the VO{sub 2} (A) microrods are presented and the possible formation steps for the flower-like morphologies of VO{sub 2} (M1) are described. - Graphical abstract: Using a single step and template free hydrothermal synthesis, well crystallized VO{sub 2} (A) microrods were prepared and the P4/ncc space group was assigned to the room temperature crystal structure. Reversible and irreversible phase transitions among different VO{sub 2} polymorphs were identified and their progressive nature was highlighted. Attempts to increase the microrods size, involving layer by layer formation mechanisms, are presented. - Highlights: • Highly crystallized VO{sub 2} (A) microrods were grown via a single step hydrothermal process. • The P4/ncc space group was determined for VO{sub 2} (A) at room temperature. • The electronic structure and progressive nature of the structural phase transition were investigated. • A weak coupling between structural and electronic phase transitions was identified. • Different crystallite morphologies were discussed in relation with growth mechanisms.« less

  17. Managing the Security of Nursing Data in the Electronic Health Record

    PubMed Central

    Samadbeik, Mahnaz; Gorzin, Zahra; Khoshkam, Masomeh; Roudbari, Masoud

    2015-01-01

    Background: The Electronic Health Record (EHR) is a patient care information resource for clinicians and nursing documentation is an essential part of comprehensive patient care. Ensuring privacy and the security of health information is a key component to building the trust required to realize the potential benefits of electronic health information exchange. This study was aimed to manage nursing data security in the EHR and also discover the viewpoints of hospital information system vendors (computer companies) and hospital information technology specialists about nursing data security. Methods: This research is a cross sectional analytic-descriptive study. The study populations were IT experts at the academic hospitals and computer companies of Tehran city in Iran. Data was collected by a self-developed questionnaire whose validity and reliability were confirmed using the experts’ opinions and Cronbach’s alpha coefficient respectively. Data was analyzed through Spss Version 18 and by descriptive and analytic statistics. Results: The findings of the study revealed that user name and password were the most important methods to authenticate the nurses, with mean percent of 95% and 80%, respectively, and also the most significant level of information security protection were assigned to administrative and logical controls. There was no significant difference between opinions of both groups studied about the levels of information security protection and security requirements (p>0.05). Moreover the access to servers by authorized people, periodic security update, and the application of authentication and authorization were defined as the most basic security requirements from the viewpoint of more than 88 percent of recently-mentioned participants. Conclusions: Computer companies as system designers and hospitals information technology specialists as systems users and stakeholders present many important views about security requirements for EHR systems and nursing electronic documentation systems. Prioritizing of these requirements helps policy makers to decide what to do when planning for EHR implementation. Therefore, to make appropriate security decisions and to achieve the expected level of protection of the electronic nursing information, it is suggested to consider the priorities of both groups of experts about security principles and also discuss the issues seem to be different between two groups of participants in the research. PMID:25870490

  18. Managing the security of nursing data in the electronic health record.

    PubMed

    Samadbeik, Mahnaz; Gorzin, Zahra; Khoshkam, Masomeh; Roudbari, Masoud

    2015-02-01

    The Electronic Health Record (EHR) is a patient care information resource for clinicians and nursing documentation is an essential part of comprehensive patient care. Ensuring privacy and the security of health information is a key component to building the trust required to realize the potential benefits of electronic health information exchange. This study was aimed to manage nursing data security in the EHR and also discover the viewpoints of hospital information system vendors (computer companies) and hospital information technology specialists about nursing data security. This research is a cross sectional analytic-descriptive study. The study populations were IT experts at the academic hospitals and computer companies of Tehran city in Iran. Data was collected by a self-developed questionnaire whose validity and reliability were confirmed using the experts' opinions and Cronbach's alpha coefficient respectively. Data was analyzed through Spss Version 18 and by descriptive and analytic statistics. The findings of the study revealed that user name and password were the most important methods to authenticate the nurses, with mean percent of 95% and 80%, respectively, and also the most significant level of information security protection were assigned to administrative and logical controls. There was no significant difference between opinions of both groups studied about the levels of information security protection and security requirements (p>0.05). Moreover the access to servers by authorized people, periodic security update, and the application of authentication and authorization were defined as the most basic security requirements from the viewpoint of more than 88 percent of recently-mentioned participants. Computer companies as system designers and hospitals information technology specialists as systems users and stakeholders present many important views about security requirements for EHR systems and nursing electronic documentation systems. Prioritizing of these requirements helps policy makers to decide what to do when planning for EHR implementation. Therefore, to make appropriate security decisions and to achieve the expected level of protection of the electronic nursing information, it is suggested to consider the priorities of both groups of experts about security principles and also discuss the issues seem to be different between two groups of participants in the research.

  19. Phylogenetic analysis of proteins associated in the four major energy metabolism systems: photosynthesis, aerobic respiration, denitrification, and sulfur respiration.

    PubMed

    Tomiki, Takeshi; Saitou, Naruya

    2004-08-01

    The four electron transfer energy metabolism systems, photosynthesis, aerobic respiration, denitrification, and sulfur respiration, are thought to be evolutionarily related because of the similarity of electron transfer patterns and the existence of some homologous proteins. How these systems have evolved is elusive. We therefore conducted a comprehensive homology search using PSI-BLAST, and phylogenetic analyses were conducted for the three homologous groups (groups 1-3) based on multiple alignments of domains defined in the Pfam database. There are five electron transfer types important for catalytic reaction in group 1, and many proteins bind molybdenum. Deletions of two domains led to loss of the function of binding molybdenum and ferredoxin, and these deletions seem to be critical for the electron transfer pattern changes in group 1. Two types of electron transfer were found in group 2, and all its member proteins bind siroheme and ferredoxin. Insertion of the pyridine nucleotide disulfide oxidoreductase domain seemed to be the critical point for the electron transfer pattern change in this group. The proteins belonging to group 3 are all flavin enzymes, and they bind flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN). Types of electron transfer in this group are divergent, but there are two common characteristics. NAD(P)H works as an electron donor or acceptor, and FAD or FMN transfers electrons from/to NAD(P)H. Electron transfer functions might be added to these common characteristics by the addition of functional domains through the evolution of group 3 proteins. Based on the phylogenetic analyses in this study and previous studies, we inferred the phylogeny of the energy metabolism systems as follows: photosynthesis (and possibly aerobic respiration) and the sulfur/nitrogen assimilation system first diverged, then the sulfur/nitrogen dissimilation system was produced from the latter system.

  20. Thymic Carcinoma Management Patterns among International Thymic Malignancy Interest Group (ITMIG) Physicians with Consensus from the Thymic Carcinoma Working Group.

    PubMed

    Shepherd, Annemarie; Riely, Gregory; Detterbeck, Frank; Simone, Charles B; Ahmad, Usman; Huang, James; Korst, Robert; Rajan, Arun; Rimner, Andreas

    2017-04-01

    Thymic carcinomas are rare epithelial malignancies with limited data to guide management. To identify areas of agreement and variability in current clinical practice, a 16-question electronic survey was given to members of the International Thymic Malignancy Interest Group (ITMIG). Areas of controversy were discussed with the Thymic Carcinoma Working Group and consensus was achieved, as described. A total of 100 ITMIG members responded. There was general agreement regarding the role for multimodality therapy with definitive surgical resection in physically fit patients with advanced but resectable disease. Areas of controversy included the need for histologic confirmation before surgery, the role of adjuvant therapy, the optimal first-line chemotherapy regimen, and the recommended treatment course for marginally resectable disease with invasion into the great vessels, pericardium, and lungs. The results of the questionnaire provide a description of the management of thymic carcinoma by 100 ITMIG members with a specific interest or expertise in thymic malignancies. Although there was agreement in some areas, clinical practice appears to vary significantly. There is a great need for collaborative research to identify optimal evaluation and treatment strategies. Given the need for multimodality therapy in many cases, a multidisciplinary discussion of the management of patients with thymic carcinoma is critical. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  1. Safeguarding the process of drug administration with an emphasis on electronic support tools

    PubMed Central

    Seidling, Hanna M; Lampert, Anette; Lohmann, Kristina; Schiele, Julia T; Send, Alexander J F; Witticke, Diana; Haefeli, Walter E

    2013-01-01

    Aims The aim of this work is to understand the process of drug administration and identify points in the workflow that resulted in interventions by clinical information systems in order to improve patient safety. Methods To identify a generic way to structure the drug administration process we performed peer-group discussions and supplemented these discussions with a literature search for studies reporting errors in drug administration and strategies for their prevention. Results We concluded that the drug administration process might consist of up to 11 sub-steps, which can be grouped into the four sub-processes of preparation, personalization, application and follow-up. Errors in drug handling and administration are diverse and frequent and in many cases not caused by the patient him/herself, but by family members or nurses. Accordingly, different prevention strategies have been set in place with relatively few approaches involving e-health technology. Conclusions A generic structuring of the administration process and particular error-prone sub-steps may facilitate the allocation of prevention strategies and help to identify research gaps. PMID:24007450

  2. A study of the possible characteristics of a low-altitude electron layer in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Wallio, H. A.

    1974-01-01

    The apparent diurnal Martian surface pressure variations, as deduced from radio occultation experiments, is discussed and explained as possibly arising from the effect of a low-altitude electron layer. Possible source and loss mechanisms for the low altitude electron layer are presented and discussed. Time dependent differential equations describing the electron layer are derived, and then integrated to investigate the electron distribution resulting from several processes that might occur in the atmosphere. It is concluded that the source mechanism is the sublimation of alkali atoms from a permanent dust layer, and that the dominant loss process must involve CO2 clustering about the alkali atoms. An electron layer is developed which explains the apparent diurnal surface pressure variation.

  3. Challenges for Electronics in the Vision for Space Exploration

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.

    2005-01-01

    This presentation has been a brief snapshot discussing electronics and Exploration-related challenges. The vision for Space Exploration creates a new paradigm for NASA missions. This includes transport (Crew Exploration Vehicle-CEV), and lunar and Mars Exploration and human presence. If one considers the additional hazards faced by these concepts versus more traditional NASA missions, multiple challenges surface for reliable utilization of electronic parts. The true challenge is to provide a risk as low as reasonably achievable (ALARA-a traditional biological radiation exposure term), while still providing cost effective solutions. This presentation also discusses the hazard for electronic parts and exploration, the types of electronic parts for exploration, and the critical juncture for space usage of commercial changes in the electronics world.

  4. Conformational control of cofactors in nature: The effect of methoxy group orientation on the electronic structure of ubisemiquinone

    NASA Astrophysics Data System (ADS)

    De Almeida, Wagner B.; O'Malley, Patrick J.

    2018-03-01

    Ubiquinone is the key electron and proton transfer agent in biology. Its mechanism involves the formation of its intermediate one-electron reduced form, the ubisemiquinone radical. This is formed in a protein-bound form which permits the semiquinone to vary its electronic and redox properties. This can be achieved by hydrogen bonding acceptance by one or both oxygen atoms or as we now propose by restricted orientations for the methoxy groups of the headgroup. We show how the orientation of the two methoxy groups of the quinone headgroup affects the electronic structure of the semiquinone form and demonstrate a large dependence of the ubisemiquinone spin density distribution on the orientation each methoxy group takes with respect to the headgroup ring plane. This is shown to significantly modify associated hyperfine couplings which in turn needs to be accounted for in interpreting experimental values in vivo. The study uncovers the key potential role the methoxy group orientation can play in controlling the electronic structure and spin density of ubisemiquinone and provides an electronic-level insight into the variation in electron affinity and redox potential of ubiquinone as a function of the methoxy orientation. Taken together with the already known influence of cofactor conformation on heme and chlorophyll electronic structure, it reveals a more widespread role for cofactor conformational control of electronic structure and associated electron transfer in biology.

  5. Two-photon or higher-order absorbing optical materials and methods of use

    NASA Technical Reports Server (NTRS)

    Perry, Joseph (Inventor); Marder, Seth (Inventor)

    2001-01-01

    Compositions capable of simultaneous two-photon absorption and higher order absorptivities are disclosed. Many of these compositions are compounds satisfying the formulae D-.PI.-D, A-.PI.-A, D-A-D and A-D-A, wherein D is an electron donor group, A is an electron acceptor group and .PI. comprises a bridge of .pi.-conjugated bonds connecting the electron donor groups and electron acceptor groups. In A-D-A and D-A-D compounds, the .pi. bridge is substituted with electron donor groups and electron acceptor groups, respectively. Also disclosed are methods that generate an electronically excited state of a compound, including those satisfying one of these formulae. The electronically excited state is achieved in a method that includes irradiating the compound with light. Then, the compound is converted to a multi-photon electronically excited state upon simultaneous absorption of at least two photons of light. The sum of the energies of all of the absorbed photons is greater than or equal to the transition energy from a ground state of the compound to the multi-photon excited state. The energy of each absorbed photon is less than the transition energy between the ground state and the lowest single-photon excited state of the compound is less than the transition energy between the multi-photon excited state and the ground state.

  6. Electronic prompts significantly increase response rates to postal questionnaires: a randomized trial within a randomized trial and meta-analysis.

    PubMed

    Clark, Laura; Ronaldson, Sarah; Dyson, Lisa; Hewitt, Catherine; Torgerson, David; Adamson, Joy

    2015-12-01

    To assess the effectiveness of sending electronic prompts to randomized controlled trial participants to return study questionnaires. A "trial within a trial" embedded within a study determining the effectiveness of chronic obstructive pulmonary disease (DOC) screening on smoking cessation. Those participants taking part in DOC who provided a mobile phone number and/or an electronic mail address were randomized to either receive an electronic prompt or no electronic prompt to return a study questionnaire. The results were combined with two previous studies in a meta-analysis. A total of 437 participants were randomized: 226 to the electronic prompt group and 211 to the control group. A total of 285 (65.2%) participants returned the follow-up questionnaire: 157 (69.5%) in the electronic prompt group and 128 (60.7%) in the control group [difference 8.8%; 95% confidence interval (CI): -0.11%, 17.7%; P = 0.05]. The mean time to response was 23 days in the electronic prompt group and 33 days in the control group (hazard ratio = 1.27; 95% CI: 1.105, 1.47). The meta-analysis of all three studies showed an increase in response rate of 7.1% (95% CI: 0.8%, 13.3%). The use of electronic prompts increased response rates and reduces the time to response. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. A coproduced patient and public event: An approach to developing and prioritizing ambulance performance measures.

    PubMed

    Irving, Andy; Turner, Janette; Marsh, Maggie; Broadway-Parkinson, Andrea; Fall, Dan; Coster, Joanne; Siriwardena, A Niroshan

    2018-02-01

    Patient and public involvement (PPI) is recognized as an important component of high-quality health services research. PPI is integral to the Pre-hospital Outcomes for Evidence Based Evaluation (PhOEBE) programme. The PPI event described in detail in this article focusses on the process of involving patients and public representatives in identifying, prioritizing and refining a set of outcome measures that can be used to support ambulance service performance measurement. To obtain public feedback on little known, complex aspects of ambulance service performance measurement. The event was codesigned and coproduced with the PhOEBE PPI reference group and PhOEBE research team. The event consisted of brief researcher-led presentations, group discussions facilitated by the PPI reference group members and electronic voting. Data were collected from eighteen patient and public representatives who attended an event venue in Yorkshire. The results of the PPI event showed that this interactive format and mode of delivery was an effective method to obtain public feedback and produced a clear indication of which ambulance performance measures were most highly favoured by event participants. The event highlighted valuable contributions the PPI reference group made to the design process, supporting participant recruitment and facilitation of group discussions. In addition, the positive team working experience of the event proved a catalyst for further improvements in PPI within the PhOEBE project. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

  8. Accessing Electronic Theses: Progress?

    ERIC Educational Resources Information Center

    Tennant, Roy

    2000-01-01

    Describes various ways by which universities provide access to their electronic theses and dissertations (ETDs), discussing UMI (University Microfilms International), XML (eXtensible Markup Language), and other formats. Discusses key leaders--national and international--in the ETD effort. Outlines the two main methods for locating ETDs. Presents a…

  9. Graphene-based organic-inorganic hybrids with optoelectronic and magneto-optic functions (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lee, Kwang-Sup; Kim, Sung-Hyun; Jung, Juhyoung; Teng, Xue-Cheng; Prabhakaran, Prem

    2017-02-01

    Groups around the world are pursuing optoelctronic and magneto-optic properties of graphene-based materials since they hold a lot of promise for future technologies. Quantum dot (QD) decorated graphenic nanohybrids can be candidates for demonstrating energy transfer, while magnetic nanoparticles (MNPs) on graphene give rise to interesting electronic phenomena like magneto-optical effects. Graphene containing MNPs are also good candidates for exploring quantum-hall effect. In medicine these materials have demonstrated applications in bioimaging, drug delivery, photothermal treatment and magnetic resonance imaging. A majority of groups working on QD or MNPs have focused on chemical functionalization methods for making graphene-MNP nanohybrids. We have developed a set of small molecule as well as polymeric ligands for noncovalent self-assembly of nanoparticles on graphene. The ligands contain pyrene as an anchor group for graphene and also thiol or dipamine as anchor groups for QD or MNPs. In this presentation we discuss the synthesis and characterization of these materials and outline some early results regarding exploratory device fabrication involving these materials.

  10. Synthesis and characterization of covalently bound benzocaine graphite oxide derivative

    NASA Astrophysics Data System (ADS)

    Kabbani, Ahmad; Kabbani, Mohamad; Safadi, Khadija

    2015-09-01

    Graphite oxide (GO) derived materials include chemically functionalize or reduced graphene oxide (exfoliated from GO) sheets, assembled paper-like forms , and graphene-based composites GO consists of intact graphitic regions interspersed with sp3-hybridized carbons containing hydroxyl and epoxide functional groups on the top and bottom surfaces of each sheet and sp2-hybridized carbons containing carboxyl and carbonyl groups mostly at the sheet edges. Hence, GO is hydrophilic and readily disperses in water to form stable colloidal suspensions Due to the attached oxygen functional groups, GO was used to prepare different derivatives which result in some physical and chemical properties that are dramatically different from their bulk counterparts .The present work discusses the covalent cross linking of graphite oxide to benzocaine or ethyl ester of para-aminobenzoic acid,structure I,used in many over-the-counter ointment drug.Synthesis is done via diazotization of the amino group.The product is characterized via IR,Raman, X-ray photoelectron spectroscopy as well as electron microscopy.

  11. Overview of MEMS/NEMS technology development for space applications at NASA/JPL

    NASA Astrophysics Data System (ADS)

    George, Thomas

    2003-04-01

    This paper highlights the current technology development activities of the MEMS Technology Group at JPL. A diverse range of MEMS/NEMS technologies are under development, that are primarily applicable to NASA"s needs in the area of robotic planetary exploration. MEMS/NEMS technologies have obvious advantages for space applications, since they offer the promise of highly capable devices with ultra low mass, size and power consumption. However, the key challenge appears to be in finding efficient means to transition these technologies into "customer" applications. A brief description of this problem is presented along with the Group"s innovative approach to rapidly advance the maturity of technologies via insertion into space missions. Also described are some of the major capabilities of the MEMS Technology Group. A few important examples from among the broad classes of technologies being developed are discussed, these include the "Spider Web Bolometer", High-Performance Miniature Gyroscopes, an Electron Luminescence X-ray Spectrometer, a MEMS-based "Knudsen" Thermal Transpiration pump, MEMS Inchworm Actuators, and Nanowire-based Biological/Chemical Sensors.

  12. General synthesis and physicochemical characterisation of a series of peptide-mimic lysine-based amino-functionalised lipids.

    PubMed

    Wölk, Christian; Drescher, Simon; Meister, Annette; Blume, Alfred; Langner, Andreas; Dobner, Bodo

    2013-09-16

    A series of novel malonic acid diamides (second generation) with two long hydrophobic alkyl chains and an alkaline polar head group was synthesised and characterised as a new class of amino-functionalised lipids. These peptide-mimic lipids are suitable for polynucleotide transfer. The lipids bear a novel backbone consisting of a lysine unit and a malonic acid unit. Six different head-group structures, which vary in size and number of amino groups that can be protonated, were attached to the backbone structure. Furthermore, different alkyl chains were used to build the lipophilic part (namely tetradecyl, hexadecyl, and oleyl). Phase transitions of the new compounds in aqueous dispersions at pH 10 were analysed and discussed in terms of head group and alkyl chain variations. The shape and size of the formed aggregates of selected lipid dispersions were investigated by dynamic light scattering and transmission electron microscopy. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Influence of the position of the methoxy group on the stabilities of the syn and anti conformers of 4-, 5-, and 6-methoxyindole

    NASA Astrophysics Data System (ADS)

    Wilke, Martin; Brand, Christian; Wilke, Josefin; Schmitt, Michael

    2017-07-01

    Even though the two possible rotamers of methoxy-substituted indoles only differ in the orientation of a methoxy group, this slight geometry change can have a strong influence on the stabilities and further molecular properties of the conformers. In the present study, we evaluate the effect of the methyl group position on the presence of different conformers in molecular beam studies for the systems 4-, 5-, and 6-methoxyindole. By using rotationally resolved electronic Stark spectroscopy in combination with high level ab initio calculations the structures of the observable conformers have been assigned and reasons for the absence of the missing conformers discussed. Thereby, we could show that the relative ground state energies and isomerization barriers for both conformers strongly depend on the position of the methoxy group and are the main explanation for the absence of the syn conformers of 4-, and 5-methoxyindole.

  14. Local Group dSph radio survey with ATCA - II. Non-thermal diffuse emission

    NASA Astrophysics Data System (ADS)

    Regis, Marco; Richter, Laura; Colafrancesco, Sergio; Profumo, Stefano; de Blok, W. J. G.; Massardi, Marcella

    2015-04-01

    Our closest neighbours, the Local Group dwarf spheroidal (dSph) galaxies, are extremely quiescent and dim objects, where thermal and non-thermal diffuse emissions lack, so far, of detection. In order to possibly study the dSph interstellar medium, deep observations are required. They could reveal non-thermal emissions associated with the very low level of star formation, or to particle dark matter annihilating or decaying in the dSph halo. In this work, we employ radio observations of six dSphs, conducted with the Australia Telescope Compact Array in the frequency band 1.1-3.1 GHz, to test the presence of a diffuse component over typical scales of few arcmin and at an rms sensitivity below 0.05 mJy beam-1. We observed the dSph fields with both a compact array and long baselines. Short spacings led to a synthesized beam of about 1 arcmin and were used for the extended emission search. The high-resolution data mapped background sources, which in turn were subtracted in the short-baseline maps, to reduce their confusion limit. We found no significant detection of a diffuse radio continuum component. After a detailed discussion on the modelling of the cosmic ray (CR) electron distribution and on the dSph magnetic properties, we present bounds on several physical quantities related to the dSphs, such that the total radio flux, the angular shape of the radio emissivity, the equipartition magnetic field, and the injection and equilibrium distributions of CR electrons. Finally, we discuss the connection to far-infrared and X-ray observations.

  15. Electronic Commerce and Competitive Procurement

    DTIC Science & Technology

    1991-06-01

    electronic commerce techniques ( electronic Jata interchange (EDI). electronic mail ( E -mail), electronic bulletin boards and facsimile] to competitive ...The ability to conduct discussions and negotiations with offerors electronically by E -mail supports the competitive proposal solicitation method...software vendors understand the dimensions of the DoD electronic commerce market , they may through competitive forces provide EDI capability. If their

  16. Report from the fourth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative).

    PubMed

    Chalmers, J R; Simpson, E; Apfelbacher, C J; Thomas, K S; von Kobyletzki, L; Schmitt, J; Singh, J A; Svensson, Å; Williams, H C; Abuabara, K; Aoki, V; Ardeleanu, M; Awici-Rasmussen, M; Barbarot, S; Berents, T L; Block, J; Bragg, A; Burton, T; Bjerring Clemmensen, K K; Creswell-Melville, A; Dinesen, M; Drucker, A; Eckert, L; Flohr, C; Garg, M; Gerbens, L A A; Graff, A L B; Hanifin, J; Heinl, D; Humphreys, R; Ishii, H A; Kataoka, Y; Leshem, Y A; Marquort, B; Massuel, M-A; Merhand, S; Mizutani, H; Murota, H; Murrell, D F; Nakahara, T; Nasr, I; Nograles, K; Ohya, Y; Osterloh, I; Pander, J; Prinsen, C; Purkins, L; Ridd, M; Sach, T; Schuttelaar, M-L A; Shindo, S; Smirnova, J; Sulzer, A; Synnøve Gjerde, E; Takaoka, R; Vestby Talmo, H; Tauber, M; Torchet, F; Volke, A; Wahlgren, C-F; Weidinger, S; Weisshaar, E; Wollenberg, A; Yamaga, K; Zhao, C Y; Spuls, P I

    2016-07-01

    This article is a report of the fourth meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in Malmö, Sweden on 23-24 April 2015 (HOME IV). The aim of the meeting was to achieve consensus over the preferred outcome instruments for measuring patient-reported symptoms and quality of life for the HOME core outcome set for atopic eczema (AE). Following presentations, which included data from systematic reviews, consensus discussions were held in a mixture of whole group and small group discussions. Small groups were allocated a priori to ensure representation of different stakeholders and countries. Decisions were voted on using electronic keypads. For the patient-reported symptoms, the group agreed by vote that itch, sleep loss, dryness, redness/inflamed skin and irritated skin were all considered essential aspects of AE symptoms. Many instruments for capturing patient-reported symptoms were discussed [including the Patient-Oriented SCOring Atopic Dermatitis index, Patient-Oriented Eczema Measure (POEM), Self-Administered Eczema Area and Severity Index, Itch Severity Scale, Atopic Dermatitis Quickscore and the Nottingham Eczema Severity Score] and, by consensus, POEM was selected as the preferred instrument to measure patient-reported symptoms. Further work is needed to determine the reliability and measurement error of POEM. Further work is also required to establish the importance of pain/soreness and the importance of collecting information regarding the intensity of symptoms in addition to their frequency. Much of the discussion on quality of life concerned the Dermatology Life Quality Index and Quality of Life Index for Atopic Dermatitis; however, consensus on a preferred instrument for measuring this domain could not be reached. In summary, POEM is recommended as the HOME core outcome instrument for measuring AE symptoms. © 2016 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

  17. On the generation of magnetosheath lion roars

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, L.C.; Wu, C.S.; Price, C.P.

    1987-03-01

    A theoretical model is proposed to discuss the electron dynamics associated with the mirror waves and their effects on the generation of the observed lion roars in the magnetosheath. It is pointed out that the usual double-adiabatic theory of hydromagnetics is not applicable to the electrons in mirror waves. Although the electron magnetic moment is conserved, the energy of each electron in the mirror waves is expected to be constant (because of the high electron speed along the magnetic field). Assuming an initial electron temperature anisotropy, the authors can show that in the low field region the electron temperature andmore » thermal anisotropy are higher than the initial values, whereas in the high field region the electron temperature and anisotropy are lower. This point can lead to a theoretical explanation of the important features of the observed lion roars. The present discussion complements the existing theories in the literature.« less

  18. Single-Molecule Bioelectronics

    PubMed Central

    Rosenstein, Jacob K.; Lemay, Serge G.; Shepard, Kenneth L.

    2014-01-01

    Experimental techniques which interface single biomolecules directly with microelectronic systems are increasingly being used in a wide range of powerful applications, from fundamental studies of biomolecules to ultra-sensitive assays. Here we review several technologies which can perform electronic measurements of single molecules in solution: ion channels, nanopore sensors, carbon nanotube field-effect transistors, electron tunneling gaps, and redox cycling. We discuss the shared features among these techniques that enable them to resolve individual molecules, and discuss their limitations. Recordings from each of these methods all rely on similar electronic instrumentation, and we discuss the relevant circuit implementations and potential for scaling these single-molecule bioelectronic interfaces to high-throughput arrayed sensing platforms. PMID:25529538

  19. Design of a cluster-randomized trial of electronic health record-based tools to address overweight and obesity in primary care.

    PubMed

    Baer, Heather J; Wee, Christina C; DeVito, Katerina; Orav, E John; Frolkis, Joseph P; Williams, Deborah H; Wright, Adam; Bates, David W

    2015-08-01

    Primary care providers often fail to identify patients who are overweight or obese or discuss weight management with them. Electronic health record-based tools may help providers with the assessment and management of overweight and obesity. We describe the design of a trial to examine the effectiveness of electronic health record-based tools for the assessment and management of overweight and obesity among adult primary care patients, as well as the challenges we encountered. We developed several new features within the electronic health record used by primary care practices affiliated with Brigham and Women's Hospital in Boston, MA. These features included (1) reminders to measure height and weight, (2) an alert asking providers to add overweight or obesity to the problem list, (3) reminders with tailored management recommendations, and (4) a Weight Management screen. We then conducted a pragmatic, cluster-randomized controlled trial in 12 primary care practices. We randomized 23 clinical teams ("clinics") within the practices to the intervention group (n = 11) or the control group (n = 12). The new features were activated only for clinics in the intervention group. The intervention was implemented in two phases: the height and weight reminders went live on 15 December 2011 (Phase 1), and all of the other features went live on 11 June 2012 (Phase 2). Study enrollment went from December 2011 through December 2012, and follow-up ended in December 2013. The primary outcomes were 6-month and 12-month weight change among adult patients with body mass index ≥25 who had a visit at one of the primary care clinics during Phase 2. Secondary outcome measures included the proportion of patients with a recorded body mass index in the electronic health record, the proportion of patients with body mass index ≥25 who had a diagnosis of overweight or obesity on the electronic health record problem list, and the proportion of patients with body mass index ≥25 who had a follow-up appointment about their weight or were prescribed weight loss medication. We encountered challenges in our development of an intervention within the existing structure of an electronic health record. For example, although we decided to randomize clinics within primary care practices, this decision may have introduced contamination and led to some imbalance of patient characteristics between the intervention and control practices. Using the electronic health record as the primary data source reduced the cost of the study, but not all desired data were recorded for every participant. Despite the challenges, this study should provide valuable information about the effectiveness of electronic health record-based tools for addressing overweight and obesity in primary care. © The Author(s) 2015.

  20. Generation of low-emittance electron beams in electrostatic accelerators for FEL applications

    NASA Astrophysics Data System (ADS)

    Chen, Teng; Elias, Luis R.

    1995-02-01

    This paper reports results of transverse emittance studies and beam propagation in electrostatic accelerators for free electron laser applications. In particular, we discuss emittance growth analysis of a low current electron beam system consisting of a miniature thermoionic electron gun and a National Electrostatics Accelerator (NEC) tube. The emittance growth phenomenon is discussed in terms of thermal effects in the electron gun cathode and aberrations produced by field gradient changes occurring inside the electron gun and throughout the accelerator tube. A method of reducing aberrations using a magnetic solenoidal field is described. Analysis of electron beam emittance was done with the EGUN code. Beam propagation along the accelerator tube was studied using a cylindrically symmetric beam envelope equation that included beam self-fields and the external accelerator fields which were derived from POISSON simulations.

  1. On the generation of magnetosheath lion roars

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Wu, C. S.; Price, C. P.

    1987-01-01

    A theoretical model is proposed to discuss the electron dynamics associated with the mirror waves and their effects on the generation of the observed lion roars in the magnetosheath. It is pointed out that the usual double-adiabatic theory of hydromagnetics is not applicable to the electrons in mirror waves. Although the electron magnetic moment is conserved, the energy of each electron in the mirror waves is expected to be constant. Assuming an initial electron temperature anisotropy, it can be shown that in the low field region the electron temperature and thermal anisotropy are higher than the initial values, whereas in the high field region the electron temperature and anisotropy are lower. This point can lead to a theoretical explanation of the important features of the observed lion roars. Then present discussion complements the existing theories in the literature.

  2. A Randomized Controlled Trial of an Electronic Informed Consent Process

    PubMed Central

    Rothwell, Erin; Wong, Bob; Rose, Nancy C.; Anderson, Rebecca; Fedor, Beth; Stark, Louisa A.; Botkin, Jeffrey R.

    2018-01-01

    A pilot study assessed an electronic informed consent model within a randomized controlled trial (RCT). Participants who were recruited for the parent RCT project were randomly selected and randomized to either an electronic consent group (n = 32) or a simplified paper-based consent group (n = 30). Results from the electronic consent group reported significantly higher understanding of the purpose of the study, alternatives to participation, and who to contact if they had questions or concerns about the study. However, participants in the paper-based control group reported higher mean scores on some survey items. This research suggests that an electronic informed consent presentation may improve participant understanding for some aspects of a research study. PMID:25747685

  3. What Does Electronic Conferencing Afford Distance Education?

    ERIC Educational Resources Information Center

    Barnes, Sally

    2000-01-01

    Discusses the use of technology for distance learning in higher education and examines the similarities and differences between face-to-face seminars and online discussions. Considers the concept of affordance in relation to information and communication technologies and distance education; and examines affordances of electronic conferencing and…

  4. Forces Shaping the Electronic Publishing Industry of the 1990s.

    ERIC Educational Resources Information Center

    Hawkins, Donald T.; And Others

    1992-01-01

    Reviews the conventional publishing industry, and discusses a study of the electronic publishing industry and its products and processes. Discusses seven major forces affecting it--technology, economics, demographics, social trends, government policies, applications growth, and industry trends--and outlines principles to follow for success in…

  5. Amplified spontaneous emission of pyranyliden derivatives in PVK matrix

    NASA Astrophysics Data System (ADS)

    Vembris, Aivars; Zarinsh, Elmars; Kokars, Valdis

    2016-04-01

    One of the well-known red light emitting laser dyes is 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4Hpyran (DCM). Amplified spontaneous emission (ASE) has been widely investigated of DCM molecules or its derivatives in polymer or low molecular weight matrix. The main issue for these molecules is aggregation which limits doping concentration in matrix. Lowest ASE threshold values within concentration range of 2 and 4 wt% were obtained. In this work ASE properties of two original DCM derivatives in poly(N-vinylcarbazole) (PVK) at various concentrations will be discussed. One of the derivatives is the same DCM dye with replaced butyl groups at electron donor part with bulky trytiloxyethyl groups (DWK-1). These groups do not influence electron transitions in the dye but prevent aggregation of the molecules. Second derivative (DWK-2) consists of two equal donor groups with the attached trytiloxyethyl groups. All results were compared with DCM:PVK system. Photoluminescence quantum yield (PLQY) is almost three times larger for DWK-1 concentration up to 20wt% with respect to DCM systems. PLQY was saturated on 0.06 at higher DWK-1 concentrations. Bulky trytiloxyethyl groups prevent aggregation of the molecules thus decreasing interaction between dyes and numbers of non-radiative decays. Red shift of photoluminescence and amplified spontaneous emission at higher concentrations were observed due to the solid state solvation effect. Increases of dye density in matrix with smaller lose in PLQY resulted in low ASE threshold energy. The lowest threshold value was obtained around 29 μJ/cm2 in DWK-1:PVK films.

  6. Teaching Chemistry with Electron Density Models.

    ERIC Educational Resources Information Center

    Shusterman, Gwendolyn P.; Shusterman, Alan J.

    1997-01-01

    Describes a method for teaching electronic structure and its relevance to chemical phenomena that relies on computer-generated three-dimensional models of electron density distributions. Discusses the quantum mechanical background needed and presents ways of using models of electronic ground states to teach electronic structure, bonding concepts,…

  7. Non-conjugated, phenyl assisted coupling in through bond electron transfer in a perylenemonoimide-triphenylamine system.

    PubMed

    Bell, Toby D M; Stefan, Alina; Lemaur, Vincent; Bernhardt, Stefan; Müllen, Klaus; Cornil, Jérôme; Beljonne, David; Hofkens, Johan; Van der Auweraer, Mark; De Schryver, Frans C

    2007-04-01

    Two donor-bridge-acceptor compounds containing triphenylamine (TPA) donors and perylenemonoimide (PMI) acceptors have been studied by spectroscopic techniques and quantum chemical computation. Both systems have been observed to emit prompt and delayed fluorescence under certain conditions indicating that forward and reverse electron transfer (ET) processes can occur between the locally excited and the charge separated states. The experimental and computational results show that the TPA and PMI chromophores are better coupled by almost 50% in the meta isomers which undergo ET more readily than the para isomers. Quantum chemical calculations indicate that this unexpected situation is the result of a phenyl group on the side of the bridge being advantageously positioned in the meta isomers. This leads to more extensive delocalisation of the TPA HOMO into the bridge enhancing the total through bond electronic coupling between the TPA and PMI chromophores. The calculations also indicate a strong angle dependence of the total coupling in both isomers. The experimental results are discussed in the context of the high temperature limit of Marcus's theory of non-adiabatic ET.

  8. The Application of Metal Oxide Nanomaterials for Chemical Sensor Development

    NASA Technical Reports Server (NTRS)

    Xu, Jennifer C.; Hunter, Gary W.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.

    2007-01-01

    NASA Glenn Research Center (GRC) has been developing miniature chemical sensors for a variety of applications including fire detection, emissions monitoring, fuel leak detection, and environmental monitoring. Smart Lick and Stick sensor technology which integrates a sensor array, electronics, telemetry, and power into one microsystem are being developed. These microsystems require low power consumption for long-term aerospace applications. One approach to decreasing power consumption is the use of nanotechnology. Nanocrystalline tin oxide (SnO2) carbon monoxide (CO) sensors developed previously by this group have been successfully used for fire detection and emissions monitoring. This presentation will briefly review the overall NASA GRC chemical sensor program and discuss our further effort in nanotechnology applications. New carbon dioxide (CO2) sensing material using doped nanocrystalline SnO2 will be discussed. Nanocrystalline SnO2 coated solid electrolyte CO2 sensors and SnO2 nanorod and nanofiber hydrogen (H2) sensors operated at reduced or room temperatures will also be discussed.

  9. NASA Past, Present, and Future: The Use of Commercial Off The Shelf (COTS) Electronics in Space

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.; Guertin, Steven M.

    2017-01-01

    NASA has a long history of using commercial grade electronics in space. In this presentation we will provide a brief history of NASA's trends and approaches to commercial grade electronics focusing on processing and memory systems. This will include providing summary information on the space hazards to electronics as well as NASA mission trade space. We will also discuss developing recommendations for risk management approaches to Electrical, Electronic and Electromechanical (EEE) parts usage in space. Two examples will be provided focusing on a near-earth Polar-orbiting spacecraft as well as a mission to Mars. The final portion will discuss emerging trends impacting usage.

  10. Different Effect of the Additional Electron-Withdrawing Cyano Group in Different Conjugation Bridge: The Adjusted Molecular Energy Levels and Largely Improved Photovoltaic Performance.

    PubMed

    Li, Huiyang; Fang, Manman; Hou, Yingqin; Tang, Runli; Yang, Yizhou; Zhong, Cheng; Li, Qianqian; Li, Zhen

    2016-05-18

    Four organic sensitizers (LI-68-LI-71) bearing various conjugated bridges were designed and synthesized, in which the only difference between LI-68 and LI-69 (or LI-70 and LI-71) was the absence/presence of the CN group as the auxiliary electron acceptor. Interestingly, compared to the reference dye of LI-68, LI-69 bearing the additional CN group exhibited the bad performance with the decreased Jsc and Voc values. However, once one thiophene moiety near the anchor group was replaced by pyrrole with the electron-rich property, the resultant LI-71 exhibited a photoelectric conversion efficiency increase by about 3 folds from 2.75% (LI-69) to 7.95% (LI-71), displaying the synergistic effect of the two moieties (CN and pyrrole). Computational analysis disclosed that pyrrole as the auxiliary electron donor (D') in the conjugated bridge can compensate for the lower negative charge in the electron acceptor, which was caused by the CN group as the electron trap, leading to the more efficient electron injection and better photovoltaic performance.

  11. Personal Electronic Health Records: Understanding User Requirements and Needs in Chronic Cancer Care

    PubMed Central

    Winkler, Eva; Kamradt, Martina; Längst, Gerda; Eckrich, Felicitas; Heinze, Oliver; Bergh, Bjoern; Szecsenyi, Joachim; Ose, Dominik

    2015-01-01

    Background The integration of new information and communication technologies (ICTs) is becoming increasingly important in reorganizing health care. Adapting ICTs as supportive tools to users' needs and daily practices is vital for adoption and use. Objective In order to develop a Web-based personal electronic health record (PEPA), we explored user requirements and needs with regard to desired information and functions. Methods A qualitative study across health care sectors and health professions was conducted in a regional health care setting in Germany. Overall, 10 semistructured focus groups were performed, collecting views of 3 prospective user groups: patients with colorectal cancer (n=12) and representatives from patient support groups (n=2), physicians (n=17), and non-medical HCPs (n=16). Data were audio- and videotaped, transcribed verbatim, and thematically analyzed using qualitative content analysis. Results For both patients and HCPs, it was central to have a tool representing the chronology of illness and its care processes, for example, patients wanted to track their long-term laboratory findings (eg, tumor markers). Designing health information in a patient accessible way was highlighted as important. Users wanted to have general and tumor-specific health information available in a PEPA. Functions such as filtering information and adding information by patients (eg, on their well-being or electronic communication with HCPs via email) were discussed. Conclusions In order to develop a patient/user centered tool that is tailored to user needs, it is essential to address their perspectives. A challenge for implementation will be how to design PEPA’s health data in a patient accessible way. Adequate patient support and technical advice for users have to be addressed. PMID:25998006

  12. Electronic cigarettes: a review of safety and clinical issues.

    PubMed

    Weaver, Michael; Breland, Alison; Spindle, Tory; Eissenberg, Thomas

    2014-01-01

    This clinical case conference discusses 3 cases of patients using electronic cigarettes. Electronic cigarettes, also referred to as electronic nicotine delivery systems or "e-cigarettes," generally consist of a power source (usually a battery) and a heating element (commonly referred to as an atomizer) that vaporize a solution (e-liquid). The user inhales the resulting vapor. E-liquids contain humectants such as propylene glycol and/or vegetable glycerin, flavorings, and usually, but not always, nicotine. Each patient's information is an amalgamation of actual patients and is presented and then followed by a discussion of clinical issues.

  13. Electroactive materials for organic electronics: preparation strategies, structural aspects and characterization techniques.

    PubMed

    Pron, Adam; Gawrys, Pawel; Zagorska, Malgorzata; Djurado, David; Demadrille, Renaud

    2010-07-01

    This critical review discusses specific chemical and physicochemical requirements which must be met for organic compounds to be considered as promising materials for applications in organic electronics. Although emphasis is put on molecules and macromolecules suitable for fabrication of field effect transistors (FETs), a large fraction of the discussed compounds can also be applied in other organic or hybrid (organic-inorganic) electronic devices such as photodiodes, light emitting diodes, photovoltaic cells, etc. It should be of interest to chemists, physicists, material scientists and electrical engineers working in the domain of organic electronics (423 references).

  14. Point defects in crystalline zircon (zirconium silicate), ZrSiO4: electron paramagnetic resonance studies

    NASA Astrophysics Data System (ADS)

    Tennant, W. C.; Claridge, R. F. C.; Walsby, C. J.; Lees, N. S.

    This article outlines the present state of knowledge of paramagnetic defects in crystalline zircon as obtained mainly, but not exclusively, from electron paramagnetic resonance (EPR) studies in crystalline zircon (zirconium silicate, ZrSiO4). The emphasis is on single-crystal studies where, in principle, unambiguous analysis is possible. Firstly, the crystallography of zircon is presented. Secondly, the relationships between available crystal-site symmetries and the symmetries of observed paramagnetic species in zircon, and how these observations lead to unambiguous assignments of point-group symmetries for particular paramagnetic species are detailed. Next, spin-Hamiltonian (SH) analysis is discussed with emphasis on the symmetry relationships that necessarily exist amongst the Laue classes of the crystal sites in zircon, the paramagnetic species occupying those sites and the SH itself. The final sections of the article then survey the results of EPR studies on zircon over the period 1960-2002.

  15. Electronic structure and lattice dynamics of few-layer InSe

    NASA Astrophysics Data System (ADS)

    Webster, Lucas; Yan, Jia-An

    Studies of Group-III monochalcogenides (MX, M = Ga and In, X = S, Se, and Te) have revealed their great potentials in many optoelectronic applications, including solar energy conversion, fabrication of memory devices and solid-state batteries. Among these semiconductors, indium selenide (InSe) has attracted particular attention due to its narrower direct bandgap, which makes it suitable for photovoltaic conversion. In this work, using first-principles calculations, we present a detailed study of the energetics, atomic structures, electronic structures, and lattice dynamics of InSe layers down to two-dimensional limit, namely, monolayer InSe and bilayer InSe with various stacking geometry. Calculations using various exchange-correlation functionals and pseudopotentials are tested and compared with experimental data. The dependence of the Raman spectra on the stacking geometry and the laser polarization will also be discussed. This work is supported by the SET Grant of the Fisher College of Science and Mathematics (FCSM) at the Towson University.

  16. Three-Dimensional Electrodes for High-Performance Bioelectrochemical Systems

    PubMed Central

    Yu, Yang-Yang; Zhai, Dan-Dan; Si, Rong-Wei; Sun, Jian-Zhong; Liu, Xiang; Yong, Yang-Chun

    2017-01-01

    Bioelectrochemical systems (BES) are groups of bioelectrochemical technologies and platforms that could facilitate versatile environmental and biological applications. The performance of BES is mainly determined by the key process of electron transfer at the bacteria and electrode interface, which is known as extracellular electron transfer (EET). Thus, developing novel electrodes to encourage bacteria attachment and enhance EET efficiency is of great significance. Recently, three-dimensional (3D) electrodes, which provide large specific area for bacteria attachment and macroporous structures for substrate diffusion, have emerged as a promising electrode for high-performance BES. Herein, a comprehensive review of versatile methodology developed for 3D electrode fabrication is presented. This review article is organized based on the categorization of 3D electrode fabrication strategy and BES performance comparison. In particular, the advantages and shortcomings of these 3D electrodes are presented and their future development is discussed. PMID:28054970

  17. Using Computer Conferencing and Electronic Mail to Facilitate Group Projects.

    ERIC Educational Resources Information Center

    Anderson, Margaret D.

    1996-01-01

    Reports on the use of electronic mail and an electronic conferencing system to conduct group projects in three educational psychology courses at the State University of New York College at Cortland. Course design is explained and group project design is described, including assignments and oral presentations during regular class sessions.…

  18. 75 FR 38127 - Visteon Systems, LLC North Penn Plant Electronics Products Group Including On-Site Leased Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ..., North Penn Plant, Electronics Products Group to be covered by this certification. The intent of the... North Penn Plant Electronics Products Group Including On-Site Leased Workers From Ryder Integrated... Certification Regarding Eligibility To Apply for Worker Adjustment Assistance and Alternative Trade Adjustment...

  19. Intellectual and Economic Fuel for the Electronics Revolution

    ERIC Educational Resources Information Center

    Linvill, John G.; Hogan, C. Lester

    1977-01-01

    Reviews the evolution of semiconductor electronics, shows how it served and was strengthened by space and defense missions; discusses how new enterprises formed as semiconductor electronics developed. (MLH)

  20. σ-Hole Bond vs π-Hole Bond: A Comparison Based on Halogen Bond.

    PubMed

    Wang, Hui; Wang, Weizhou; Jin, Wei Jun

    2016-05-11

    The σ-hole and π-hole are the regions with positive surface electrostatic potential on the molecule entity; the former specifically refers to the positive region of a molecular entity along extension of the Y-Ge/P/Se/X covalent σ-bond (Y = electron-rich group; Ge/P/Se/X = Groups IV-VII), while the latter refers to the positive region in the direction perpendicular to the σ-framework of the molecular entity. The directional noncovalent interactions between the σ-hole or π-hole and the negative or electron-rich sites are named σ-hole bond or π-hole bond, respectively. The contributions from electrostatic, charge transfer, and other terms or Coulombic interaction to the σ-hole bond and π-hole bond were reviewed first followed by a brief discussion on the interplay between the σ-hole bond and the π-hole bond as well as application of the two types of noncovalent interactions in the field of anion recognition. It is expected that this review could stimulate further development of the σ-hole bond and π-hole bond in theoretical exploration and practical application in the future.

  1. Solitons, Lie Group Analysis and Conservation Laws of a (3+1)-Dimensional Modified Zakharov-Kuznetsov Equation in a Multicomponent Magnetised Plasma

    NASA Astrophysics Data System (ADS)

    Du, Xia-Xia; Tian, Bo; Chai, Jun; Sun, Yan; Yuan, Yu-Qiang

    2017-11-01

    In this paper, we investigate a (3+1)-dimensional modified Zakharov-Kuznetsov equation, which describes the nonlinear plasma-acoustic waves in a multicomponent magnetised plasma. With the aid of the Hirota method and symbolic computation, bilinear forms and one-, two- and three-soliton solutions are derived. The characteristics and interaction of the solitons are discussed graphically. We present the effects on the soliton's amplitude by the nonlinear coefficients which are related to the ratio of the positive-ion mass to negative-ion mass, number densities, initial densities of the lower- and higher-temperature electrons and ratio of the lower temperature to the higher temperature for electrons, as well as by the dispersion coefficient, which is related to the ratio of the positive-ion mass to the negative-ion mass and number densities. Moreover, using the Lie symmetry group theory, we derive the Lie point symmetry generators and the corresponding symmetry reductions, through which certain analytic solutions are obtained via the power series expansion method and the (G'/G) expansion method. We demonstrate that such an equation is strictly self-adjoint, and the conservation laws associated with the Lie point symmetry generators are derived.

  2. Barriers and facilitators to electronic documentation in a rural hospital.

    PubMed

    Whittaker, Alice A; Aufdenkamp, Marilee; Tinley, Susan

    2009-01-01

    The purpose of the study was to explore nurses' perceptions of barriers and facilitators to adoption of an electronic health record (EHR) in a rural Midwestern hospital. This study was a qualitative, descriptive design. The Staggers and Parks Nurse-Computer Interaction Framework was used to guide directed content analysis. Eleven registered nurses from oncology and medical-surgical units were interviewed using three semistructured interview questions. Predetermined codes and operational definitions were developed from the Staggers and Parks framework. Narrative data were analyzed by each member of the research team and group consensus on coding was reached through group discussions. Participants were able to identify computer-related, nurse-related, and contextual barriers and facilitators to implementation of EHR. In addition, two distinct patterns of perceptions and acceptance were identified. The Staggers and Parks Nurse-Computer Interaction framework was found to be useful in identifying computer, nurse, and contextual characteristics that act as facilitators or barriers to adoption of an EHR system. Acceptance and use of an EHR are enhanced when barriers are managed and facilitators are supported. Understanding and management of facilitators and barriers to EHR adoption may impact nurses' ability to provide and document nursing care.

  3. Electronic Media, Videodisc Technology, and the Visual Arts.

    ERIC Educational Resources Information Center

    Anderson, Frances E.

    1985-01-01

    The potential of electronic media for art education is examined. Discussed are computers, video recorders, interactive video discs, and two-way cable television. Emphasis is on laser videodisc technology. What changes must occur in the educational system to accommodate technology and discipline-based art education are also discussed. (Author/RM)

  4. Electronic Commerce, Digital Information, and the Firm.

    ERIC Educational Resources Information Center

    Rosenbaum, Howard

    2000-01-01

    Discussion of the social context of electronic commerce (ecommerce) focuses on information imperatives, or rules that are critical for ecommerce firms. Concludes with a discussion of the organizational changes that can be expected to accompany the incorporation of these imperatives into the mission and core business processes of ecommerce firms.…

  5. "YOUR VIEWS SHOWED TRUE IGNORANCE!!!": (Mis)Communication in an Online Interracial Discussion Forum.

    ERIC Educational Resources Information Center

    McKee, Heidi

    2002-01-01

    Focuses on the dynamics of interracial electronic communication. Examines the misunderstandings that arose in this interracial discussion, situating the causes and consequences of the students' discourse within both the local context of the electronic forum and within wider cultural patterns. Suggests strategies for facilitating more productive…

  6. A Model for Web-based Information Systems in E-Retailing.

    ERIC Educational Resources Information Center

    Wang, Fang; Head, Milena M.

    2001-01-01

    Discusses the use of Web-based information systems (WIS) by electronic retailers to attract and retain consumers and deliver business functions and strategy. Presents an abstract model for WIS design in electronic retailing; discusses customers, business determinants, and business interface; and suggests future research. (Author/LRW)

  7. Why NASA and the Space Electronics Community Cares About Cyclotrons

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.

    2017-01-01

    NASA and the space community are faced with the harsh reality of operating electronic systems in the space radiation environment. Systems need to work reliably (as expected for as long as expected) and be available during critical operations such as docking or firing a thruster. This talk will provide a snapshot of the import of ground-based research on the radiation performance of electronics. Discussion topics include: 1) The space radiation environment hazard, 2) Radiation effects on electronics, 3) Simulation of effects with cyclotrons (and other sources), 4) Risk prediction for space missions, and, 5) Real-life examples of both ground-based testing and space-based anomalies and electronics performance. The talk will conclude with a discussion of the current state of radiation facilities in North America for ground-based electronics testing.

  8. Dose-dependent high-resolution electron ptychography

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    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.

  9. A Value-Added Framework for Analyzing Electronic and Print Publishing.

    ERIC Educational Resources Information Center

    Perritt, Henry H., Jr.

    1991-01-01

    Discusses changes in the publishing industry resulting from digital electronic networks and optical storage technologies, and explains attributes of information products as types of value for both print and electronic contexts. Electronic products necessary for a shift from paper to electronic formats are identified, and legal issues are…

  10. Activation of a medical emergency team using an electronic medical recording-based screening system*.

    PubMed

    Huh, Jin Won; Lim, Chae-Man; Koh, Younsuck; Lee, Jury; Jung, Youn-Kyung; Seo, Hyun-Suk; Hong, Sang-Bum

    2014-04-01

    To evaluate the efficacy of a medical emergency team activated using 24-hour monitoring by electronic medical record-based screening criteria followed by immediate intervention by a skilled team. Retrospective cohort study. Academic tertiary care hospital with approximately 2,700 beds. A total of 3,030 events activated by a medical emergency team from March 1, 2008, to February 28, 2010. None. We collected data for all medical emergency team activations: patient characteristics, trigger type for medical emergency team (electronic medical record-based screening vs calling criteria), interventions during each event, outcomes of the medical emergency team intervention, and 28-day mortality after medical emergency team activation. We analyzed data for 2009, when the medical emergency team functioned 24 hours a day, 7 days a week (period 2), compared with that for 2008, when the medical emergency team functioned 12 hours a day, 7 days a week (period 1). The commonest cause of medical emergency team activation was respiratory distress (43.6%), and the medical emergency team performed early goal-directed therapy (21.3%), respiratory care (19.9%), and difficult airway management (12.3%). For patients on general wards, 51.3% (period 1) and 38.4% (period 2) of medical emergency team activations were triggered by the electronic medical record-based screening system (electronic medical record-triggered group). In 23.4%, activation occurred because of an abnormality in laboratory screening criteria. The commonest activation criterion from electronic medical record-based screening was respiratory rate (39.4%). Over half the patients were treated in the general ward, and one third of the patients were transferred to the ICU. The electronic medical record-triggered group had lower ICU admission with an odds ratio of 0.35 (95% CI, 0.22-0.55). In surgical patients, the electronic medical record-triggered group showed the lower 28-day mortality (10.5%) compared with the call-triggered group (26.7%) or the double-triggered group (33.3%) (odds ratio 0.365 with 95% CI, 0.154-0.867, p = 0.022). We successful managed the medical emergency team with electronic medical record-based screening criteria and a skilled intervention team. The electronic medical record-triggered group had lower ICU admission than the call-triggered group or the double-triggered group. In surgical patients, the electronic medical record-triggered group showed better outcome than other groups.

  11. Structure-Activity Relationships for Pt-Free Metal Phosphide Hydrogen Evolution Electrocatalysts.

    PubMed

    Owens-Baird, Bryan; Kolen'ko, Yury V; Kovnir, Kirill

    2018-05-23

    In the field of renewable energy, the splitting of water into hydrogen and oxygen fuel gases using water electrolysis is a prominent topic. Traditionally, these catalytic processes have been performed by platinum-group metal catalysts, which are effective at promoting water electrolysis but expensive and rare. The search for an inexpensive and Earth-abundant catalyst has led to the development of 3d-transition-metal phosphides for the hydrogen evolution reaction. These catalysts have shown excellent activity and stability. In this review, we discuss the electronic and crystal structures of bulk and surface of selected Fe, Co, and Ni phosphides, and their relationships to the experimental catalytic activity. The various synthetic protocols towards the state-of-the-art transition metal phosphide electrocatalysts are also discussed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Models of Electron Energetics in the Enceladus Torus

    NASA Astrophysics Data System (ADS)

    Cravens, T. E.; Ozak, N.; Richard, M. S.; Robertson, I. P.; Perry, M. E.; Campbell, M. E.

    2010-12-01

    The inner magnetosphere of Saturn contains a mixture of plasma and neutral gas, the dominant source of which is the icy satellite Enceladus. Water vapor and water dissociation products are present throughout the magnetosphere but they are particularly concentrated in a torus surrounding Saturn at the orbit of Enceladus. The Hubble Space Telescope observed OH in the torus and other neutral species (mainly water) have been measured by the Ion and Neutral Mass Spectrometer (INMS) and the Ultraviolet Imaging Spectrometer (UVIS) onboard the Cassini spacecraft. Relatively cold plasma, dominated by water group ion species, was measured by instruments onboard both the Voyager and Cassini spacecraft. The electron distribution function in this torus appears to include both a colder thermal population (seen for example by the Cassini Radio and Plasma Wave Spectrometer’s Langmuir probe -- RPWS/LP) and hotter suprathermal populations (seen by the electron spectrometer part of the Cassini plasma analyzer -- CAPS/ELS). We present a model of electron energetics in the torus. One part of this model utilizes an electron energy deposition code to determine electron fluxes versus energy. The model includes photoelectron production from the absorption of solar radiation as well as electron impact collisional processes for water and other neutral species. Another part of the model consists of an energetics code for thermal electrons that generates electron temperatures. Heating from Coulomb collisions with photoelectrons and with hot pick-up ions was included, as was cooling due to electron impact collisions with water. We show that solar radiation is the dominant source of suprathermal electrons in the core neutral torus, in agreement with recently published CAPS-ELS data. We predict electron thermal energies of about 2 eV, which is somewhat low in comparison with recently published RPWS-LP data. The implications of these results for plasma densities in the torus will also be discussed.

  13. Principal Challenges Facing Electronic Records Management in Federal Agencies Today.

    ERIC Educational Resources Information Center

    Patterson, Giovanna; Sprehe, J. Timothy

    2002-01-01

    Discusses electronic records management in the federal government. Highlights include managing electronic mail; information technology planning, systems design, and architecture; updating conventional records management; integrating electronic records management with other information technology systems; challenges of end-user training; business…

  14. Carbon Nanotube Based Molecular Electronics

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Saini, Subhash; Menon, Madhu

    1998-01-01

    Carbon nanotubes and the nanotube heterojunctions have recently emerged as excellent candidates for nanoscale molecular electronic device components. Experimental measurements on the conductivity, rectifying behavior and conductivity-chirality correlation have also been made. While quasi-one dimensional simple heterojunctions between nanotubes with different electronic behavior can be generated by introduction of a pair of heptagon-pentagon defects in an otherwise all hexagon graphene sheet. Other complex 3- and 4-point junctions may require other mechanisms. Structural stability as well as local electronic density of states of various nanotube junctions are investigated using a generalized tight-binding molecular dynamics (GDBMD) scheme that incorporates non-orthogonality of the orbitals. The junctions investigated include straight and small angle heterojunctions of various chiralities and diameters; as well as more complex 'T' and 'Y' junctions which do not always obey the usual pentagon-heptagon pair rule. The study of local density of states (LDOS) reveal many interesting features, most prominent among them being the defect-induced states in the gap. The proposed three and four pointjunctions are one of the smallest possible tunnel junctions made entirely of carbon atoms. Furthermore the electronic behavior of the nanotube based device components can be taylored by doping with group III-V elements such as B and N, and BN nanotubes as a wide band gap semiconductor has also been realized in experiments. Structural properties of heteroatomic nanotubes comprising C, B and N will be discussed.

  15. Understanding children's sedentary behaviour: a qualitative study of the family home environment.

    PubMed

    Granich, Joanna; Rosenberg, Michael; Knuiman, Matthew; Timperio, Anna

    2010-04-01

    Electronic media (EM) (television, electronic games and computer) use has been associated with overweight and obesity among children. Little is known about the time spent in sedentary behaviour (SB) among children within the family context. The aim of this study was to explore how the family home environment may influence children's electronic-based SB. Focus groups and family interviews were conducted with 11- to 12-year old children (n = 54) and their parents (n = 38) using a semi-structured discussion guide. Transcripts were analysed using a thematic content approach. A brief self-completed questionnaire was also used to measure leisure behaviour and electronic devices at home. Children incorporated both sedentary and physical activities into their weekly routine. Factors influencing children's EM use included parent and sibling modelling and reinforcement, personal cognitions, the physical home environment and household EM use rules and restrictions. Participants were not concerned about the excessive time children spent with EM. This under-recognition emerged as a personal influencing factor and was viewed as a major barrier to modifying children's electronic-based SB. Efforts to reduce SB in children should focus on the influencing factors that reciprocally interact within the family home. An emphasis on increasing awareness about the risks associated with spending excessive time in screen-based activities should be a priority when developing intervention strategies aimed at modifying the time children spend in SB.

  16. Electronic structure and mechanical properties of plasma nitrided ferrous alloys

    NASA Astrophysics Data System (ADS)

    Portolan, E.; Baumvol, I. J. R.; Figueroa, C. A.

    2009-04-01

    The electronic structures of the near-surface regions of two different nitrided steels (AISI 316 and 4140) were investigated using X-ray photoelectron spectroscopy. Photoelectron groups from all main chemical elements involved were addressed for steel samples with implanted-N concentrations in the range 16-32 at.%. As the implanted-N concentrations were increased, rather contrasting behaviors were observed for the two kinds of steel. The N1s photoelectrons had spectral shifts toward lower (nitrided AISI 316) or higher (nitrided AISI 4140) binding energies, whereas the Fe2p 3/2 photoelectron spectrum remains at a constant binding energy (nitrided AISI 316) or shifts toward higher binding energies (AISI 4140). These trends are discussed in terms of the metallic nitride formation and the overlapping of atomic orbitals. For nitrided AISI 316, a semi-classical approach of charge transfer between Cr and N is used to explain the experimental facts (formation of CrN), while for nitrided AISI 4140 we propose that the interaction between orbitals 4s from Fe and 2p from N promotes electrons to the conduction band increasing the electrical attraction of the N1s and Fe2p electrons in core shells (formation of FeN x). The increase in hardness of the steel upon N implantation is attributed to the localization of electrons in specific bonds, which diminishes the metallic bond character.

  17. Sputtering of water ice films: A re-assessment with singly and doubly charged oxygen and argon ions, molecular oxygen, and electrons

    NASA Astrophysics Data System (ADS)

    Galli, A.; Vorburger, A.; Wurz, P.; Tulej, M.

    2017-07-01

    We studied the erosion rates from thin water ice films on a microbalance upon irradiation with ions (O+, O2+, O2+ , Ar+ , and Ar2+) and electrons at energies between 0.1 keV and 80 keV. The results with O+ and Ar+ irradiation confirm previous results of other research groups that relied on the same experiment set-up. In addition, we assessed how the ice film thickness affects the results and we compared the results for singly versus doubly charged ions and for O+ versus O2+ ions. The irradiation with 1 keV and 3 keV electrons offer the first experimental results at these energies. Our results confirm theoretical predictions that the yield per impacting electron does not increase with energy ad infinitum but rather levels off between 0.1 and 1 keV. The results for ion and electron sputtering have important implications for atmosphere-less icy bodies in a plasma environment. We briefly discuss the implications for the icy moons of Jupiter. Finally, the experiments also allow us to assess the viability of two methods to measure the erosion rate in the case that the icy sample cannot be attached on a microbalance. This is an important step for future laboratory studies where regolith ice samples and their reaction to particle irradiation are to be characterized.

  18. Conventional taxonomy of lactobacilli surviving radurization of meat.

    PubMed

    Hastings, J W; Holzapfel, W H

    1987-03-01

    All of the 113 catalase-negative, Gram-positive, rod-shaped strains isolated from radurized minced beef (5 kGy) were homofermentative, non-thermophilic, and belonged to the sub-genus Streptobacterium. The majority of the strains (100) were identified as Lactobacillus sake. These were divided into four sub-groups based on their sugar fermentation pattern: group IA1 (melibiose (+), maltose (-), amygdalin (-), 76 strains); group IA2 (melibiose (+), maltose (-), amygdalin (+), 14 strains); group IB1 (melibiose (+), maltose (+), amygdalin (+), four strains); group IB2 (melibiose (+), maltose (+), amygdalin (-), six strains). Of the remaining strains, two produced L(+)-lactic acid and were identified as L. farciminis, three were identified as L. curvatus and eight showed characteristics of both L. sake and L. curvatus and were designated 'L. sake/curvatus.' With one exception, all strains were aciduric and relatively insensitive to the chemical preservatives tested. Most L. sake strains produced significant amounts of H2O2. Electron microscopy confirmed a possible relationship between the thickness of the cells and radiation resistance. The problems and limitations of this type of taxonomic study and possible reasons for the predominance of L. sake species in radurized meat are discussed.

  19. QSPR/QSAR in N-[(dimethylamine)methyl] benzamides substituents groups influence upon electronic distribution and local anesthetics activity.

    PubMed

    Tavares, Leoberto Costa; do Amaral, Antonia Tavares

    2004-03-15

    It was determined, with a systematic mode, the carbonyl group frequency in the region of the infrared of N-[(dimethylamine)methyl] benzamides 4-substituted (set A) and their hydrochlorides (set B), that had its local anesthetical activity evaluated. The application of the Hammett equation considering the values of the absorption frequency of carbonyl group, nu(C=O,) using the electronic constants sigma, sigma(I), sigma(R), I and R leads to meaningful correlation. The nature and the contribution of substituent group electronic effects on the polarity of the carbonyl group was also analyzed. The use of the nu(C=O) as an experimental electronic parameter for QSPR studies was validated.

  20. Structure-Function of the Cytochrome b 6f Complex of Oxygenic Photosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cramer, W. A.; Yamashita, E.; Baniulis, D.

    2014-03-20

    Structure–function of the major integral membrane cytochrome b 6f complex that functions in cyanobacteria, algae, and green plants to transfer electrons between the two reaction center complexes in the electron transport chain of oxygenic photosynthesis is discussed in the context of recently obtained crystal structures of the complex and soluble domains of cytochrome f and the Rieske iron–sulfur protein. The energy-transducing function of the complex, generation of the proton trans-membrane electrochemical potential gradient, centers on the oxidation/reduction pathways of the plastoquinol/plastoquinone (QH 2/Q), the proton donor/acceptor within the complex. These redox reactions are carried out by five redox prosthetic groupsmore » embedded in each monomer, the high potential two iron–two sulfur cluster and the heme of cytochrome f on the electropositive side (p) of the complex, two noncovalently bound b-type hemes that cross the complex and the membrane, and a covalently bound c-type heme (c n) on the electronegative side (n). These five redox-active groups are organized in high- (cyt f/[2Fe–2S] and low-potential (hemes b p, b n, c n) electron transport pathways that oxidize and reduce the quinol and quinone on the p- and n-sides in a Q-cycle-type mechanism, while translocating as many as 2 H + to the p-side aqueous side for every electron transferred through the high potential chain to the photosystem I reaction center. The presence of heme c n and the connection of the n-side of the membrane and b 6f complex to the cyclic electron transport chain indicate that the Q cycle in the oxygenic photosynthetic electron transport chain differs from those connected to the bc 1 complex in the mitochondrial respiratory chain and the chain in photosynthetic bacteria. Inferences from the structure and C2 symmetry of the complex for the pathway of QH 2/Q transfer within the complex, problems posed by the presence of lipid in the inter-monomer cavity, and the narrow portal for QH2 passage through the p-side oxidation site proximal to the [2Fe–2S] cluster are discussed.« less

  1. The Effects of the SUN Project on Teacher Knowledge and Self-Efficacy Regarding Biological Energy Transfer Are Significant and Long-Lasting: Results of a Randomized Controlled Trial

    PubMed Central

    Batiza, Ann Finney; Gruhl, Mary; Zhang, Bo; Harrington, Tom; Roberts, Marisa; LaFlamme, Donna; Haasch, Mary Anne; Knopp, Jonathan; Vogt, Gina; Goodsell, David; Hagedorn, Eric; Marcey, David; Hoelzer, Mark; Nelson, Dave

    2013-01-01

    Biological energy flow has been notoriously difficult to teach. Our approach to this topic relies on abiotic and biotic examples of the energy released by moving electrons in thermodynamically spontaneous reactions. A series of analogical model-building experiences was supported with common language and representations including manipulatives. These materials were designed to help learners understand why electrons move in a hydrogen explosion and hydrogen fuel cell, so they could ultimately understand the rationale for energy transfer in the mitochondrion and the chloroplast. High school biology teachers attended a 2-wk Students Understanding eNergy (SUN) workshop during a randomized controlled trial. These treatment group teachers then took hydrogen fuel cells, manipulatives, and other materials into their regular biology classrooms. In this paper, we report significant gains in teacher knowledge and self-efficacy regarding biological energy transfer in the treatment group versus randomized controls. Significant effects on treatment group teacher knowledge and self-efficacy were found not only post–SUN workshop but even 1 yr later. Teacher knowledge was measured with both a multiple-choice exam and a drawing with a written explanation. Teacher confidence in their ability to teach biological energy transfer was measured by a modified form of the Science Teaching Efficacy Belief Instrument, In-Service A. Professional development implications regarding this topic are discussed. PMID:23737635

  2. The effects of the SUN project on teacher knowledge and self-efficacy regarding biological energy transfer are significant and long-lasting: results of a randomized controlled trial.

    PubMed

    Batiza, Ann Finney; Gruhl, Mary; Zhang, Bo; Harrington, Tom; Roberts, Marisa; LaFlamme, Donna; Haasch, Mary Anne; Knopp, Jonathan; Vogt, Gina; Goodsell, David; Hagedorn, Eric; Marcey, David; Hoelzer, Mark; Nelson, Dave

    2013-06-01

    Biological energy flow has been notoriously difficult to teach. Our approach to this topic relies on abiotic and biotic examples of the energy released by moving electrons in thermodynamically spontaneous reactions. A series of analogical model-building experiences was supported with common language and representations including manipulatives. These materials were designed to help learners understand why electrons move in a hydrogen explosion and hydrogen fuel cell, so they could ultimately understand the rationale for energy transfer in the mitochondrion and the chloroplast. High school biology teachers attended a 2-wk Students Understanding eNergy (SUN) workshop during a randomized controlled trial. These treatment group teachers then took hydrogen fuel cells, manipulatives, and other materials into their regular biology classrooms. In this paper, we report significant gains in teacher knowledge and self-efficacy regarding biological energy transfer in the treatment group versus randomized controls. Significant effects on treatment group teacher knowledge and self-efficacy were found not only post-SUN workshop but even 1 yr later. Teacher knowledge was measured with both a multiple-choice exam and a drawing with a written explanation. Teacher confidence in their ability to teach biological energy transfer was measured by a modified form of the Science Teaching Efficacy Belief Instrument, In-Service A. Professional development implications regarding this topic are discussed.

  3. The use of electronic books in midwifery education: the student perspective.

    PubMed

    Appleton, Leo

    2004-12-01

    The objectives of this paper are: (i) to illustrate the use of e-books by health studies students at a college of higher education; (ii) to provide a demonstration of how e-books may be facilitated by library and information services staff working across the health and academic sectors; (iii) to comment upon the experiences of health studies students, in using e-books. A focus group of 10 student midwives was used to gain insight into how e-books may be used in an academic context for health professionals. The findings of the student midwives' focus group are reported and discussed. In this instance, the student midwives were encouraged to use e-books as part of a structured information skills programme. The paper concentrates on how the e-books were used within this context and addresses the potential benefits and disadvantages from a student perspective. The results provide evidence of a largely positive experience of using e-books as an electronic information resource. The focus group reveals many benefits and advantages in the facilitation and use of e-books, as well as addressing areas for development. It is concluded that e-books have a place in health library and information resources, but further development of e-books and e-book collections is required and subsequent investigation into their most effective use.

  4. Quantitative Simulation of QARBM Challenge Events During Radiation Belt Enhancements

    NASA Astrophysics Data System (ADS)

    Li, W.; Ma, Q.; Thorne, R. M.; Bortnik, J.; Chu, X.

    2017-12-01

    Various physical processes are known to affect energetic electron dynamics in the Earth's radiation belts, but their quantitative effects at different times and locations in space need further investigation. This presentation focuses on discussing the quantitative roles of various physical processes that affect Earth's radiation belt electron dynamics during radiation belt enhancement challenge events (storm-time vs. non-storm-time) selected by the GEM Quantitative Assessment of Radiation Belt Modeling (QARBM) focus group. We construct realistic global distributions of whistler-mode chorus waves, adopt various versions of radial diffusion models (statistical and event-specific), and use the global evolution of other potentially important plasma waves including plasmaspheric hiss, magnetosonic waves, and electromagnetic ion cyclotron waves from all available multi-satellite measurements. These state-of-the-art wave properties and distributions on a global scale are used to calculate diffusion coefficients, that are then adopted as inputs to simulate the dynamical electron evolution using a 3D diffusion simulation during the storm-time and the non-storm-time acceleration events respectively. We explore the similarities and differences in the dominant physical processes that cause radiation belt electron dynamics during the storm-time and non-storm-time acceleration events. The quantitative role of each physical process is determined by comparing against the Van Allen Probes electron observations at different energies, pitch angles, and L-MLT regions. This quantitative comparison further indicates instances when quasilinear theory is sufficient to explain the observed electron dynamics or when nonlinear interaction is required to reproduce the energetic electron evolution observed by the Van Allen Probes.

  5. Health Care Transition Preparation and Experiences in a U.S. National Sample of Young Adults With Type 1 Diabetes.

    PubMed

    Garvey, Katharine C; Foster, Nicole C; Agarwal, Shivani; DiMeglio, Linda A; Anderson, Barbara J; Corathers, Sarah D; Desimone, Marisa E; Libman, Ingrid M; Lyons, Sarah K; Peters, Anne L; Raymond, Jennifer K; Laffel, Lori M

    2017-03-01

    Young adults with type 1 diabetes transitioning from pediatric to adult care are at risk for adverse outcomes. We developed a survey to evaluate transition experiences in two groups of young adults with type 1 diabetes, before (PEDS) and after (ADULT) transition to adult care. We fielded an electronic survey to young adults (18 to <30 years) at 60 T1D Exchange Clinic Registry centers. Surveys were completed by 602 young adults, 303 in the PEDS group (60% female, age 20 ± 2 years) and 299 in the ADULT group (62% female, age 24 ± 3 years). In the PEDS group, mean anticipated transition age was 22 ± 2 years; 64% remained in pediatric care because of emotional attachment to the provider. The ADULT group transitioned at age 19 ± 2 years, mainly after pediatric provider recommendation. More than 80% of respondents reported receiving counseling on type 1 diabetes self-management and screening tests from pediatric providers, but less than half (43% PEDS and 33% ADULT) reported discussing reproductive health. In the PEDS group, half had discussed transfer with pediatric providers. Of the ADULT participants, 63% received an adult provider referral, and 66% felt mostly/completely prepared to transition. ADULT participants with fewer pretransition pediatric visits or who felt unprepared for transition had increased odds of gaps >6 months between pediatric and adult care. Receipt of transition preparation counseling was not associated with self-reported hemoglobin A 1c <7.0% in either group. These results support the need for intensive efforts to integrate transition preparation counseling and care coordination into pediatric type 1 diabetes care. © 2017 by the American Diabetes Association.

  6. Engagement and satisfaction with an Internet-based physical activity intervention in patients with rheumatoid arthritis.

    PubMed

    van den Berg, M H; Ronday, H K; Peeters, A J; Voogt-van der Harst, E M; Munneke, M; Breedveld, F C; Vliet Vlieland, T P M

    2007-03-01

    To assess the engagement in and satisfaction with an Internet-mediated physical activity intervention with individual supervision in patients with rheumatoid arthritis (RA). The intervention studied was one of the two strategies aimed at enhancing physical activity in RA patients that were being compared in a randomized controlled trial. A total of 82 patients, all experienced in using Internet and e-mail and registered at three different rheumatology out-patient clinics, were randomly allocated to the Internet-mediated individualized intervention (52 weeks). They had access to personal physical activity schedules and received individual supervision by a physical therapist by means of weekly e-mail feedback. In addition, telephone contacts, an online discussion forum, six face-to-face group meetings and electronic newsletters were offered. Besides registration of returned physical activity schedules, engagement and satisfaction were measured through questionnaires. The median physical activity schedule return rate of the 82 participants was 55%. The mean number of patients logging into the website at least once a week was 53 (70%) over 12 months. Of all patients, 69 returned the questionnaires (response 84%). Telephone contacts were used by 38/67 patients (57%), the mean (SD) number of attended group meetings was 3.1 (1.5) and the discussion forum comprised 15 posted messages. Overall, the proportions of patients being (very) satisfied with the amount of e-mail contacts, telephone contacts, usefulness of website information, physical activity schedules, group meetings and website layout were >/=85%. A smaller proportion of patients were satisfied with the links to other websites (68%), the newsletters (55%) and the online discussion forum (32%). Physical activity schedules with weekly feedback by e-mail, telephone contacts and a limited number of group meetings were frequently used website tools and modes of communication of an Internet-based physical activity intervention, with high-satisfaction rates from RA patients. Discussion forum and newsletters were less used and appreciated. Caution should be taken when extrapolating the results found to groups of patients who are not experienced Internet and e-mail users or patients with more severe physical disabilities.

  7. Discussing uncertainty and risk in primary care: recommendations of a multi-disciplinary panel regarding communication around prostate cancer screening.

    PubMed

    Wilkes, Michael; Srinivasan, Malathi; Cole, Galen; Tardif, Richard; Richardson, Lisa C; Plescia, Marcus

    2013-11-01

    Shared decision making improves value-concordant decision-making around prostate cancer screening (PrCS). Yet, PrCS discussions remain complex, challenging and often emotional for physicians and average-risk men. In July 2011, the Centers for Disease Control and Prevention convened a multidisciplinary expert panel to identify priorities for funding agencies and development groups to promote evidence-based, value-concordant decisions between men at average risk for prostate cancer and their physicians. Two-day multidisciplinary expert panel in Atlanta, Georgia, with structured discussions and formal consensus processes. Sixteen panelists represented diverse specialties (primary care, medical oncology, urology), disciplines (sociology, communication, medical education, clinical epidemiology) and market sectors (patient advocacy groups, Federal funding agencies, guideline-development organizations). Panelists used guiding interactional and evaluation models to identify and rate strategies that might improve PrCS discussions and decisions for physicians, patients and health systems/society. Efficacy was defined as the likelihood of each strategy to impact outcomes. Effort was defined as the relative amount of effort to develop, implement and sustain the strategy. Each strategy was rated (1-7 scale; 7 = maximum) using group process software (ThinkTank(TM)). For each group, intervention strategies were grouped as financial/regulatory, educational, communication or attitudinal levers. For each strategy, barriers were identified. Highly ranked strategies to improve value-concordant shared decision-making (SDM) included: changing outpatient clinic visit reimbursement to reward SDM; development of evidence-based, technology-assisted, point-of-service tools for physicians and patients; reframing confusing prostate cancer screening messages; providing pre-visit decision support interventions; utilizing electronic health records to promote benchmarking/best practices; providing additional training for physicians around value-concordant decision-making; and using re-accreditation to promote training. Conference outcomes present an expert consensus of strategies likely to improve value-concordant prostate cancer screening decisions. In addition, the methodology used to obtain agreement provides a model of successful collaboration around this and future controversial cancer screening issues, which may be of interest to funding agencies, educators and policy makers.

  8. A randomized controlled trial of an electronic informed consent process.

    PubMed

    Rothwell, Erin; Wong, Bob; Rose, Nancy C; Anderson, Rebecca; Fedor, Beth; Stark, Louisa A; Botkin, Jeffrey R

    2014-12-01

    A pilot study assessed an electronic informed consent model within a randomized controlled trial (RCT). Participants who were recruited for the parent RCT project were randomly selected and randomized to either an electronic consent group (n = 32) or a simplified paper-based consent group (n = 30). Results from the electronic consent group reported significantly higher understanding of the purpose of the study, alternatives to participation, and who to contact if they had questions or concerns about the study. However, participants in the paper-based control group reported higher mean scores on some survey items. This research suggests that an electronic informed consent presentation may improve participant understanding for some aspects of a research study. © The Author(s) 2014.

  9. Probing the Dipolar Coupling in a Heterospin Endohedral Fullerene-Phthalocyanine Dyad.

    PubMed

    Zhou, Shen; Yamamoto, Masanori; Briggs, G Andrew D; Imahori, Hiroshi; Porfyrakis, Kyriakos

    2016-02-03

    Paramagnetic endohedral fullerenes and phthalocyanine (Pc) complexes are promising building blocks for molecular quantum information processing, for which tunable dipolar coupling is required. We have linked these two spin qubit candidates together and characterized the resulting electron paramagnetic resonance properties, including the spin dipolar coupling between the fullerene spin and the copper spin. Having interpreted the distance-dependent coupling strength quantitatively and further discussed the antiferromagnetic aggregation effect of the CuPc moieties, we demonstrate two ways of tuning the dipolar coupling in such dyad systems: changing the spacer group and adjusting the solution concentration.

  10. Magnesium, zinc, aluminium and gallium hydride complexes of the transition metals† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6cc05702k

    PubMed Central

    Butler, Michael J.

    2017-01-01

    The preparation and applications of heterobimetallic complexes continue to occupy researchers in the fields of organometallic, main group, and coordination chemistry. This interest stems from the promise these complexes hold as precursors to materials, reagents in synthesis and as new catalysis. Here we survey and organise the state-of-the-art understanding of the TM–H–M linkage (M = Mg, Zn, Al, Ga). We discuss the structure and bonding in these complexes, their known reactivity, and their largely unrealised potential in catalysis. PMID:28070586

  11. Observations of radiation damage and recovery in ammonia targets

    NASA Astrophysics Data System (ADS)

    McKee, P. M.

    2004-06-01

    The Polarized Target Group at the University of Virginia has conducted experiments at both the Stanford Linear Accelerator Center (SLAC) and the Thomas Jefferson National Accelerator Facility (JLab) in which a high-intensity (100 nA) electron beam was focused on a polarized target of solid ammonia and/ or solid, deuterated ammonia. Analysis of the target polarization data have revealed several unique characteristics of ammonia. Topics discussed include the rate of polarization decay with accumulated charge, methods of recovering polarization through target annealing and damage-induced shifts in the optimum microwave frequency used to drive the polarization.

  12. The properties and applications of nanodiamonds.

    PubMed

    Mochalin, Vadym N; Shenderova, Olga; Ho, Dean; Gogotsi, Yury

    2011-12-18

    Nanodiamonds have excellent mechanical and optical properties, high surface areas and tunable surface structures. They are also non-toxic, which makes them well suited to biomedical applications. Here we review the synthesis, structure, properties, surface chemistry and phase transformations of individual nanodiamonds and clusters of nanodiamonds. In particular we discuss the rational control of the mechanical, chemical, electronic and optical properties of nanodiamonds through surface doping, interior doping and the introduction of functional groups. These little gems have a wide range of potential applications in tribology, drug delivery, bioimaging and tissue engineering, and also as protein mimics and a filler material for nanocomposites.

  13. Computer calculation of device, circuit, equipment, and system reliability.

    NASA Technical Reports Server (NTRS)

    Crosby, D. R.

    1972-01-01

    A grouping into four classes is proposed for all reliability computations that are related to electronic equipment. Examples are presented of reliability computations in three of these four classes. Each of the three specific reliability tasks described was originally undertaken to satisfy an engineering need for reliability data. The form and interpretation of the print-out of the specific reliability computations is presented. The justification for the costs of these computations is indicated. The skills of the personnel used to conduct the analysis, the interfaces between the personnel, and the timing of the projects is discussed.

  14. Point-of-care technology supports bedside documentation.

    PubMed

    Carlson, Elizabeth; Catrambone, Cathy; Oder, Karl; Nauseda, Susan; Fogg, Lou; Garcia, Brian; Brown, Frederick M; Johnson, Mary E; Johnson, Tricia J; Llewellyn, Jane

    2010-09-01

    As the conversion to an electronic health record intensifies, the question of which data-entry device works best in what environment and situation is paramount. Specifically, what is the best mix of equipment to purchase and install on clinical units based on staff preferences and budget constraints? The authors discuss their evaluation of stationary personal computers, workshops on wheels, and handheld tablets related to timeliness of data entry and their use of focus groups to ascertain the pros/cons of data-entry devices and staff preferences. An assessment of the implications for costs related to the timeliness of data entry is also presented.

  15. Development and operation of the JAERI superconducting energy recovery linacs

    NASA Astrophysics Data System (ADS)

    Minehara, Eisuke J.

    2006-02-01

    The Japan Atomic Energy Research Institute free-electron laser (JAERI FEL) group at Tokai, Ibaraki, Japan has successfully developed one of the most advanced and newest accelerator technologies named "superconducting energy recovery linacs (ERLs)" and some applications in near future using the ERLs. In the text, the current operation and high power JAERI ERL-FEL 10 kW upgrading program, ERL-light source design studies, prevention of the stainless-steel cold-worked stress-corrosion cracking failures and decommissioning of nuclear power plants in nuclear energy industries were reported and discussed briefly as a typical application of the ERL-FEL.

  16. Van der Waals corrected DFT study of adsorption of groups VA and VIA hydrides on graphene monoxide

    NASA Astrophysics Data System (ADS)

    Notash, M. Yaghoobi; Ebrahimzadeh, A. Rastkar

    2016-06-01

    Adsorption properties of H2O, H2S, NH3 and PH3 on graphene monoxide (GMO) nano flack are investigated using density functional theory (DFT). Calculations were carried out by van der Waals correction and general gradient approximation. The adsorption energies and charge transfer between species are obtained and discussed for the considered positions of adsorbate molecules. Charge transfer analysis show that the gas molecules act as an electron acceptor in all cases. The analysis of the adsorption energies suggest GMO can be a good candidate for the adsorption of these molecules.

  17. Excess electrons in reduced rutile and anatase TiO2

    NASA Astrophysics Data System (ADS)

    Yin, Wen-Jin; Wen, Bo; Zhou, Chuanyao; Selloni, Annabella; Liu, Li-Min

    2018-05-01

    As a prototypical photocatalyst, TiO2 is a material of scientific and technological interest. In photocatalysis and other applications, TiO2 is often reduced, behaving as an n-type semiconductor with unique physico-chemical properties. In this review, we summarize recent advances in the understanding of the fundamental properties and applications of excess electrons in reduced, undoped TiO2. We discuss the characteristics of excess electrons in the bulk and at the surface of rutile and anatase TiO2 focusing on their localization, spatial distribution, energy levels, and dynamical properties. We examine specific features of the electronic states for photoexcited TiO2, for intrinsic oxygen vacancy and Ti interstitial defects, and for surface hydroxyls. We discuss similarities and differences in the behaviors of excess electrons in the rutile and anatase phases. Finally, we consider the effect of excess electrons on the reactivity, focusing on the interaction between excess electrons and adsorbates.

  18. The integration of liquid cryogen cooling and cryocoolers withsuperconducting electronic systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Green, Michael A.

    2003-07-09

    The need for cryogenic cooling has been a critical issuethat has kept superconducting electronic devices from reaching the marketplace. Even though the performance of many of the superconductingcircuits is superior to silicon electronics, the requirement forcryogenic cooling has put the superconducting devices at a seriousdisadvantage. This report discusses the process of refrigeratingsuperconducting devices with cryogenic liquids and small cryocoolers.Three types of cryocoolers are compared for vibration, efficiency, andreliability. The connection of a cryocooler to the load is discussed. Acomparison of using flexible copper straps to carry the heat load andusing heat pipe is shown. The type of instrumentation needed formonitoringmore » and controlling the cooling is discussed.« less

  19. Electronic Journal Market Overview in 1997: Part 1--The Publishers.

    ERIC Educational Resources Information Center

    Machovec, George S.

    1997-01-01

    Provides an overview of the electronic journal market and focuses on publishers doing innovative projects. Discusses predominate market models; publishers and the Internet; issues surrounding electronic journals: pricing, security, electronic page layout, copyright, backfile availability, reliability, and accessibility. Highlights selected…

  20. Electron Microscopy.

    ERIC Educational Resources Information Center

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  1. Molecular Electronic Terms and Molecular Orbital Configurations.

    ERIC Educational Resources Information Center

    Mazo, R. M.

    1990-01-01

    Discussed are the molecular electronic terms which can arise from a given electronic configuration. Considered are simple cases, molecular states, direct products, closed shells, and open shells. Two examples are provided. (CW)

  2. Tuning of electronic properties and dynamical stability of graphene oxide with different functional groups

    NASA Astrophysics Data System (ADS)

    Dabhi, Shweta D.; Jha, Prafulla K.

    2017-09-01

    The structural, electronic and vibrational properties of graphene oxide (GO) with varying proportion of epoxy and hydroxyl functional groups have been studied using density functional theory. The functional groups and oxygen density have an obvious influence on the electronic and vibrational properties. The dependence of band gap on associated functional groups and oxygen density shows a possibility of tuning the band gap of graphene by varying the functional groups as well as oxidation level. The absorption of high oxygen content in graphene leads to the gap opening and resulting in a transition from semimetal to semiconductor. Phonon dispersion curves show no imaginary frequency or no softening of any phonon mode throughout the Brillouin zone which confirms the dynamical stability of all considered GO models. Different groups and different oxygen density result into the varying characteristics of phonon modes. The computed results show good agreement with the experimental observations. Our results present interesting possibilities for engineering the electronic properties of graphene and GO and impact the fabrication of new electronics.

  3. A DATA ACQUISITION SYSTEM FOR THE STUDY OF TRANSIENT RADIATION EFFECTS ON ELECTRONIC DEVICES. Paper 5 of FOURTH RADIATION EFFECTS SYMPOSIUM, SEPTEMBER 15-16, 1959, CINCINNATI, OHIO. GENERAL SESSION PAPERS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cochrane, D.O.; Graham, F.E.; Sauer, H.S.

    1961-10-31

    ning both the transient and permanent effects that an environment of the type created by a nuclear detonation or a pulsed reactor exerts on electronic devices, is described. The design of suitable test heads for containing the electronic devices is discussed. The design of a blockhouse for use near Ground Sero when evaluating components in a weapons environment is also discussed. (C.J.G.)

  4. Miniaturized Environmental Scanning Electron Microscope for In Situ Planetary Studies

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica; Abbott, Terry; Medley, Stephanie; Gregory, Don; Thaisen, Kevin; Taylor , Lawrence; Ramsey, Brian; Jerman, Gregory; Sampson, Allen; Harvey, Ralph

    2010-01-01

    The exploration of remote planetary surfaces calls for the advancement of low power, highly-miniaturized instrumentation. Instruments of this nature that are capable of multiple types of analyses will prove to be particularly useful as we prepare for human return to the moon, and as we continue to explore increasingly remote locations in our Solar System. To this end, our group has been developing a miniaturized Environmental-Scanning Electron Microscope (mESEM) capable of remote investigations of mineralogical samples through in-situ topographical and chemical analysis on a fine scale. The functioning of an SEM is well known: an electron beam is focused to nanometer-scale onto a given sample where resulting emissions such as backscattered and secondary electrons, X-rays, and visible light are registered. Raster scanning the primary electron beam across the sample then gives a fine-scale image of the surface topography (texture), crystalline structure and orientation, with accompanying elemental composition. The flexibility in the types of measurements the mESEM is capable of, makes it ideally suited for a variety of applications. The mESEM is appropriate for use on multiple planetary surfaces, and for a variety of mission goals (from science to non-destructive analysis to ISRU). We will identify potential applications and range of potential uses related to planetary exploration. Over the past few of years we have initiated fabrication and testing of a proof-of-concept assembly, consisting of a cold-field-emission electron gun and custom high-voltage power supply, electrostatic electron-beam focusing column, and scanning-imaging electronics plus backscatter detector. Current project status will be discussed. This effort is funded through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program.

  5. Rapid electron transfer by the carbon matrix in natural pyrogenic carbon

    PubMed Central

    Sun, Tianran; Levin, Barnaby D. A.; Guzman, Juan J. L.; Enders, Akio; Muller, David A.; Angenent, Largus T.; Lehmann, Johannes

    2017-01-01

    Surface functional groups constitute major electroactive components in pyrogenic carbon. However, the electrochemical properties of pyrogenic carbon matrices and the kinetic preference of functional groups or carbon matrices for electron transfer remain unknown. Here we show that environmentally relevant pyrogenic carbon with average H/C and O/C ratios of less than 0.35 and 0.09 can directly transfer electrons more than three times faster than the charging and discharging cycles of surface functional groups and have a 1.5 V potential range for biogeochemical reactions that invoke electron transfer processes. Surface functional groups contribute to the overall electron flux of pyrogenic carbon to a lesser extent with greater pyrolysis temperature due to lower charging and discharging capacities, although the charging and discharging kinetics remain unchanged. This study could spur the development of a new generation of biogeochemical electron flux models that focus on the bacteria–carbon–mineral conductive network. PMID:28361882

  6. Electron-Beam Produced Air Plasma: Optical Measurement of Beam Current

    NASA Astrophysics Data System (ADS)

    Vidmar, Robert; Stalder, Kenneth; Seeley, Megan

    2006-10-01

    Experiments to quantify the electron beam current and distribution of beam current in air plasma are discussed. The air plasma is produced by a 100-keV 10-mA electron beam source that traverses a transmission window into a chamber with air as a target gas. Air pressure is between 1 mTorr and 760 Torr. Strong optical emissions due to electron impact ionization are observed for the N2 2^nd positive line at 337.1 nm and the N2^+ 1^st negative line at 391.4 nm. Calibration of optical emissions using signals from the isolated transmission window and a Faraday plate are discussed. The calibrated optical system is then used to quantify the electron distribution in the air plasma.

  7. Artificial photosynthetic systems: assemblies of slipped cofacial porphyrins and phthalocyanines showing strong electronic coupling.

    PubMed

    Satake, Akiharu; Kobuke, Yoshiaki

    2007-06-07

    This paper reviews selected types of structurally well defined assemblies of porphyrins and phthalocyanines with strong electronic coupling. Face-to-face, head-to-tail, slipped cofacial, and non-parallel dimeric motifs constructed by covalent and non-covalent bonds are compared in the earlier sections. Their molecular orientation, electronic overlap, and absorption and fluorescence properties are discussed with a view towards the development of artificial photosynthetic systems and molecular electronics. Complementary coordination dimers are fully satisfactory in terms of structural stability, orientation factor, pi-electronic overlap, and zero fluorescence quenching. In later sections, several polymeric and macrocyclic porphyrin assemblies constructed by a combination of covalent bonds and complementary coordination bonds are discussed from the viewpoint of light-harvesting antenna functions.

  8. Printed Carbon Nanotube Electronics and Sensor Systems.

    PubMed

    Chen, Kevin; Gao, Wei; Emaminejad, Sam; Kiriya, Daisuke; Ota, Hiroki; Nyein, Hnin Yin Yin; Takei, Kuniharu; Javey, Ali

    2016-06-01

    Printing technologies offer large-area, high-throughput production capabilities for electronics and sensors on mechanically flexible substrates that can conformally cover different surfaces. These capabilities enable a wide range of new applications such as low-cost disposable electronics for health monitoring and wearables, extremely large format electronic displays, interactive wallpapers, and sensing arrays. Solution-processed carbon nanotubes have been shown to be a promising candidate for such printing processes, offering stable devices with high performance. Here, recent progress made in printed carbon nanotube electronics is discussed in terms of materials, processing, devices, and applications. Research challenges and opportunities moving forward from processing and system-level integration points of view are also discussed for enabling practical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Modeling the Influences of Electrostatic Discharge in Materials on a Failures of Onboard Electronic Equipment in under Microgcrogravity

    NASA Astrophysics Data System (ADS)

    Grichshenko, Valentina; Zhantayev, Zhumabek; Mukushev, Acemhan

    2016-07-01

    It is known, that during SV exploitation failures of automated systems happens as the result of complex influence of Space leading to SV's shorter life span, sometimes to their lose. All of the SV, functioning in the near-Earth Space (NES), subjected to influence of different Space factors. Causes and character of failure onboard equipment are different. Many researchers think that failures of onboard electronics connected to changing solar activity level. However, by the numerous onboard experiments established that even in the absence of solar burst in magnetostatic days there are registered failures of onboard electronics. In this paper discussed the results of modeling the impact of electrostatic discharge (ESD), occurring in the materials, on a failures of electronic onboard equipment in microgravity. The paper discusses the conditions of formation and influence of electrostatic discharge in microgravity on the elements of the onboard electronics in Space. Developed technique using circuit simulation in ISIS Proteus environment is discussed. Developed the recommendations for noise immunity of on-board equipment from ESD in Space. The results are used to predict the failure rate on-board electronics with the long term of space mission. Key words: microgravity, materials, failures, onboard electronics, Space

  10. Recent Progress on Stretchable Electronic Devices with Intrinsically Stretchable Components.

    PubMed

    Trung, Tran Quang; Lee, Nae-Eung

    2017-01-01

    Stretchable electronic devices with intrinsically stretchable components have significant inherent advantages, including simple fabrication processes, a high integrity of the stacked layers, and low cost in comparison with stretchable electronic devices based on non-stretchable components. The research in this field has focused on developing new intrinsically stretchable components for conductors, semiconductors, and insulators. New methodologies and fabrication processes have been developed to fabricate stretchable devices with intrinsically stretchable components. The latest successful examples of stretchable conductors for applications in interconnections, electrodes, and piezoresistive devices are reviewed here. Stretchable conductors can be used for electrode or sensor applications depending on the electrical properties of the stretchable conductors under mechanical strain. A detailed overview of the recent progress in stretchable semiconductors, stretchable insulators, and other novel stretchable materials is also given, along with a discussion of the associated technological innovations and challenges. Stretchable electronic devices with intrinsically stretchable components such as field-effect transistors (FETs), photodetectors, light-emitting diodes (LEDs), electronic skins, and energy harvesters are also described and a new strategy for development of stretchable electronic devices is discussed. Conclusions and future prospects for the development of stretchable electronic devices with intrinsically stretchable components are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Study of structural, electronic and magneto transport properties of La0.7Ca0.2-xSrxAg0.1MnO3

    NASA Astrophysics Data System (ADS)

    Subhashini, P.; Munirathinum, B.; Krishnaiah, M.; Venkatesh, R.; Venkateswarlu, D.; Ganesan, V.

    2016-10-01

    Structural, electrical and magneto transport properties of Lanthanum based manganites La0.7Ca0.2-xSrxAg0.1MnO3 (x=0 & 0.1) synthesized by low temperature nitrate route is studied systematically. The X-ray Diffraction patterns confirm the presence of orthorhombic structure with Pnma space group. The temperature dependence of MR (-35%) from 233-272K for x=0 and an MR (-26%) from 281-309K for x=0.1composition with an overall variation of 1% is very much advantageous for device application. Interestingly, in low temperature regime, the MR value of -47% obtained in x=0.1 composition at 10T around 5K is 20% higher than the MR obtained at 10T around the metal insulator transition. Significant changes happening in the low temperature MR measurements is discussed in the light of electron-electron interactions and weak localization mechanisms while the additional broad hump responsible for flat MR is attributed to the intrinsic electronic in homogeneity driven phase competition created due to the presence of mono valent Ag ions. The complex localization mechanism associated with insulating regime is in accordance with Variable range hopping of small polarons.

  12. Control software and electronics architecture design in the framework of the E-ELT instrumentation

    NASA Astrophysics Data System (ADS)

    Di Marcantonio, P.; Coretti, I.; Cirami, R.; Comari, M.; Santin, P.; Pucillo, M.

    2010-07-01

    During the last years the European Southern Observatory (ESO), in collaboration with other European astronomical institutes, has started several feasibility studies for the E-ELT (European-Extremely Large Telescope) instrumentation and post-focal adaptive optics. The goal is to create a flexible suite of instruments to deal with the wide variety of scientific questions astronomers would like to see solved in the coming decades. In this framework INAF-Astronomical Observatory of Trieste (INAF-AOTs) is currently responsible of carrying out the analysis and the preliminary study of the architecture of the electronics and control software of three instruments: CODEX (control software and electronics) and OPTIMOS-EVE/OPTIMOS-DIORAMAS (control software). To cope with the increased complexity and new requirements for stability, precision, real-time latency and communications among sub-systems imposed by these instruments, new solutions have been investigated by our group. In this paper we present the proposed software and electronics architecture based on a distributed common framework centered on the Component/Container model that uses OPC Unified Architecture as a standard layer to communicate with COTS components of three different vendors. We describe three working prototypes that have been set-up in our laboratory and discuss their performances, integration complexity and ease of deployment.

  13. High-energy particle production in solar flares (SEP, gamma-ray and neutron emissions). [solar energetic particles

    NASA Technical Reports Server (NTRS)

    Chupp, E. L.

    1987-01-01

    Electrons and ions, over a wide range of energies, are produced in association with solar flares. Solar energetic particles (SEPs), observed in space and near earth, consist of electrons and ions that range in energy from 10 keV to about 100 MeV and from 1 MeV to 20 GeV, respectively. SEPs are directly recorded by charged particle detectors, while X-ray, gamma-ray, and neutron detectors indicate the properties of the accelerated particles (electrons and ions) which have interacted in the solar atmosphere. A major problem of solar physics is to understand the relationship between these two groups of charged particles; in particular whether they are accelerated by the same mechanism. The paper reviews the physics of gamma-rays and neutron production in the solar atmosphere and the method by which properties of the primary charged particles produced in the solar flare can be deduced. Recent observations of energetic photons and neutrons in space and at the earth are used to present a current picture of the properties of impulsively flare accelerated electrons and ions. Some important properties discussed are time scale of production, composition, energy spectra, accelerator geometry. Particular attention is given to energetic particle production in the large flare on June 3, 1982.

  14. Electron and ion Bernstein waves in Saturnian Magnetosphere

    NASA Astrophysics Data System (ADS)

    Bashir, M. F.; Waheed, A.; Ilie, R.; Naeem, I.; Maqsood, U.; Yoon, P. H.

    2017-12-01

    The study of Bernstein mode is presented in order to interpret the observed micro-structures (MIS) and banded emission (BEM) in the Saturnian magnetosphere. The general dispersion relation of Bernstein wave is derived using the Lerche-NewBerger sum rule for the kappa distribution function and further analyzed the both electron Bernstein (EB) and ion Bernstein (IB) waves. The observational data of particle measurements is obtained from the electron spectrometer (ELS) and the ion mass spectrometer (IMS), which are part of the Cassini Plasma Spectrometer (CAPS) instrument suite on board the Cassini spacecraft. For additional electron data, the measurements of Low Energy Magnetospheric Measurements System of the Magnetospheric Imaging Instrument (LEMMS /MIMI) are also utilized. The effect of kappa spectral index, density ratio (nohe/noce for EB and nohe/noi for IB) and the temperature ratio (The/Tce for EB and The/T(h,c)i for IB) on the dispersion properties are discussed employing the exact numerical analysis to explain the appearing of additional maxima/minima (points where the perpendicular group velocity vanishes, i.e., ∂w/∂k = 0) above/below the lower (for IB) and upper hybrid (EB) bands in the observation and their relation to the MIS and BED. The results of these waves may also be compared with the simulation results of Space Weather Modeling Framework (SWMF) .

  15. The effect of including a 'psychooncological statement' in the discharge summary on patient-physician communication: a randomized controlled trial.

    PubMed

    Book, Katrin; Dinkel, Andreas; Henrich, Gerhard; Stuhr, Claudia; Peuker, Mareike; Härtl, Kristin; Brähler, Elmar; Herschbach, Peter

    2013-12-01

    The objective of this study is to determine whether the inclusion of a 'psychooncological statement' (PO-statement) in the discharge summary enhances patient-physician communication about psychosocial issues across the inpatient and outpatient sector. A total of 1416 cancer patients were randomly assigned to the intervention (with PO-statement in the discharge summary) or control group (discharge summary without PO-statement). Shortly before discharge from the hospital (T1), patients from the intervention group were screened for psychosocial distress. Based on the electronic clinical documentation system, screening results were subsequently integrated into the discharge summary, which automatically generated a PO-statement. To determine the effect of the PO-statement, patients as well as their primary care physicians (n = 596) were asked during follow-up care (T2) whether psychosocial distress was discussed during the last consultation. Including a PO-statement in the discharge summary did not result in more frequent discussions about psychosocial issues compared with the control group from the patients' and physicians' perspectives. Instead, discussions about psychosocial well-being were significantly associated with women of the patient (p = <0.001) and the physician (p = 0.011), medical discipline (gynecologists; p = 0.002), cancer diagnosis (gynecological cancer; p = 0.002), metastases (p = <0.001), professional training of patients (none, p = 0.026), and psychosocial qualification of physicians (p = 0.018). Written information on psychosocial distress in the discharge summary alone does not affect communication. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Inverse photoelectron spectrometer with magnetically focused electron gun

    NASA Technical Reports Server (NTRS)

    Krainsky, Isay L.

    1991-01-01

    An inverse photoelectron spectrometer is described which is based on the design of a magnetically focused low energy electron gun. The magnetic lens extends its field over a relatively large segment of the electron trajectory, which could provide a better focusing effect on a high-current-density low-velocity electron beam, providing the magnetic field in the vicinity of the target is reduced sufficiently to preserve the collinearity of the beam. In order to prove the concept, ray tracing is conducted using the Herrmannsfeldt program for solving electron trajectories in electrostatic and magnetostatic focusing systems. The program allows the calculation of the angles of the electron trajectories with the z axis, at the target location. The results of the ray-tracing procedure conducted for this gun are discussed. Some of the advantages of the magnetic focusing are also discussed.

  17. An empirical polytrope law for solar wind thermal electrons between 0.45 and 4.76 AU: Voyager 2 and Mariner 10

    NASA Technical Reports Server (NTRS)

    Sittler, E. C., Jr.; Scudder, J. D.

    1979-01-01

    Empirical evidence is presented that solar wind thermal electrons obey a polytrope law with polytrope index gamma = 1.175 plus or minus 0.03. The Voyager 2 and Mariner 10 data used as evidence are compared and discussed. The theoretical predictions that solar wind thermal electrons in the asymptotic solar wind should obey a polytrope law with polytrope index gamma = 1.16 plus or minus. The widespread impressions in the literature that solar wind electrons behave more like an isothermal than adiabatic gas, and the arguments that Coulomb collisions are the dominant stochastic process shaping observed electron distribution functions in the solar wind are reexamined, reviewed and evaluated. The assignment of the interplanetary potential as equal to approximately seven times the temperature of the thermal electrons is discussed.

  18. 76 FR 64428 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... open meeting. SUMMARY: In 1998 the Internal Revenue Service established the Electronic Tax... for discussion of electronic tax administration issues in support of the overriding goal that...

  19. 77 FR 70879 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-27

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... open meeting. SUMMARY: In 1998, the Internal Revenue Service established the Electronic Tax... for discussion of electronic tax administration issues in support of the overriding goal that...

  20. 77 FR 31441 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-25

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... open meeting. SUMMARY: In 1998 the Internal Revenue Service established the Electronic Tax... for discussion of electronic tax administration issues in support of the overriding goal that...

  1. The Key Ingredients of the Electronic Structure of FeSe

    NASA Astrophysics Data System (ADS)

    Coldea, Amalia I.; Watson, Matthew D.

    2018-03-01

    FeSe is a fascinating superconducting material at the frontier of research in condensed matter physics. Here, we provide an overview of the current understanding of the electronic structure of FeSe, focusing in particular on its low-energy electronic structure as determined from angle-resolved photoemission spectroscopy, quantum oscillations, and magnetotransport measurements of single-crystal samples. We discuss the unique place of FeSe among iron-based superconductors, as it is a multiband system exhibiting strong orbitally dependent electronic correlations and unusually small Fermi surfaces and is prone to different electronic instabilities. We pay particular attention to the evolution of the electronic structure that accompanies the tetragonal-orthorhombic structural distortion of the lattice around 90 K, which stabilizes a unique nematic electronic state. Finally, we discuss how the multiband multiorbital nematic electronic structure impacts our understanding of the superconductivity, and show that the tunability of the nematic state with chemical and physical pressure helps to disentangle the role of different competing interactions relevant for enhancing superconductivity.

  2. Recent Progress of Self-Powered Sensing Systems for Wearable Electronics.

    PubMed

    Lou, Zheng; Li, La; Wang, Lili; Shen, Guozhen

    2017-12-01

    Wearable/flexible electronic sensing systems are considered to be one of the key technologies in the next generation of smart personal electronics. To realize personal portable devices with mobile electronics application, i.e., wearable electronic sensors that can work sustainably and continuously without an external power supply are highly desired. The recent progress and advantages of wearable self-powered electronic sensing systems for mobile or personal attachable health monitoring applications are presented. An overview of various types of wearable electronic sensors, including flexible tactile sensors, wearable image sensor array, biological and chemical sensor, temperature sensors, and multifunctional integrated sensing systems is provided. Self-powered sensing systems with integrated energy units are then discussed, separated as energy harvesting self-powered sensing systems, energy storage integrated sensing systems, and all-in-on integrated sensing systems. Finally, the future perspectives of self-powered sensing systems for wearable electronics are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Electron swarm properties under the influence of a very strong attachment in SF6 and CF3I obtained by Monte Carlo rescaling procedures

    NASA Astrophysics Data System (ADS)

    Mirić, J.; Bošnjaković, D.; Simonović, I.; Petrović, Z. Lj; Dujko, S.

    2016-12-01

    Electron attachment often imposes practical difficulties in Monte Carlo simulations, particularly under conditions of extensive losses of seed electrons. In this paper, we discuss two rescaling procedures for Monte Carlo simulations of electron transport in strongly attaching gases: (1) discrete rescaling, and (2) continuous rescaling. The two procedures are implemented in our Monte Carlo code with an aim of analyzing electron transport processes and attachment induced phenomena in sulfur-hexafluoride (SF6) and trifluoroiodomethane (CF3I). Though calculations have been performed over the entire range of reduced electric fields E/n 0 (where n 0 is the gas number density) where experimental data are available, the emphasis is placed on the analysis below critical (electric gas breakdown) fields and under conditions when transport properties are greatly affected by electron attachment. The present calculations of electron transport data for SF6 and CF3I at low E/n 0 take into account the full extent of the influence of electron attachment and spatially selective electron losses along the profile of electron swarm and attempts to produce data that may be used to model this range of conditions. The results of Monte Carlo simulations are compared to those predicted by the publicly available two term Boltzmann solver BOLSIG+. A multitude of kinetic phenomena in electron transport has been observed and discussed using physical arguments. In particular, we discuss two important phenomena: (1) the reduction of the mean energy with increasing E/n 0 for electrons in \\text{S}{{\\text{F}}6} and (2) the occurrence of negative differential conductivity (NDC) in the bulk drift velocity only for electrons in both \\text{S}{{\\text{F}}6} and CF3I. The electron energy distribution function, spatial variations of the rate coefficient for electron attachment and average energy as well as spatial profile of the swarm are calculated and used to understand these phenomena.

  4. Selection criteria and facilitation training for the study of groupware

    NASA Technical Reports Server (NTRS)

    Robichaux, Barry P.

    1993-01-01

    Computer support for planning and decision making groups is a growing trend in the 90s. Groupware is a name often applied to group software and has been defined as 'computer-based systems that support groups engaged in a common task (or goal) and that provide an interface to a shared environment'. Unlike most single-user software, groupware assists user groups in their collaboration, coordination, and communication efforts. This paper focuses on groupware to support the meeting process. These systems are often called group decision support systems (GDSS), electronic meeting systems (EMS), or group support systems (GSS). The term 'meeting support groupware' is used here to include any computer-based system to support meetings. In order to understand this technology, one must first understand groups, what they do and the problems they face, and groupware, a wide range of technology to support group work. Guidelines for selecting groups for study as part of an overall research plan are provided in this document. These were taken from the literature and from persons for whom the information in this paper was targeted. Also, guidelines for facilitation training are discussed. Familiarity with known and accepted techniques are the principle duties of the facilitator and any form of training must include practice in using these techniques.

  5. An Examination of Electronic Cigarette Content on Social Media: Analysis of E-Cigarette Flavor Content on Reddit.

    PubMed

    Wang, Lei; Zhan, Yongcheng; Li, Qiudan; Zeng, Daniel D; Leischow, Scott J; Okamoto, Janet

    2015-11-20

    In recent years, the emerging electronic cigarette (e-cigarette) marketplace has shown great development prospects all over the world. Reddit, one of the most popular forums in the world, has a very large user group and thus great influence. This study aims to gain a systematic understanding of e-cigarette flavors based on data collected from Reddit. Flavor popularity, mixing, characteristics, trends, and brands are analyzed. Fruit flavors were mentioned the most (n = 15,720) among all the posts and were among the most popular flavors (n = 2902) used in mixed blends. Strawberry and vanilla flavors were the most popular for e-juice mixing. The number of posts discussing e-cigarette flavors has increased sharply since 2014. Mt. Baker Vapor and Hangen were the most popular brands discussed among users. Information posted on Reddit about e-cigarette flavors reflected consumers' interest in a variety of flavors. Our findings suggest that Reddit could be used for data mining and analysis of e-cigarette-related content. Understanding how e-cigarette consumers' view and utilize flavors within their vaping experience and how producers and marketers use social media to promote flavors and sell products could provide valuable information for regulatory decision-makers.

  6. An Examination of Electronic Cigarette Content on Social Media: Analysis of E-Cigarette Flavor Content on Reddit

    PubMed Central

    Wang, Lei; Zhan, Yongcheng; Li, Qiudan; Zeng, Daniel D.; Leischow, Scott J.; Okamoto, Janet

    2015-01-01

    In recent years, the emerging electronic cigarette (e-cigarette) marketplace has shown great development prospects all over the world. Reddit, one of the most popular forums in the world, has a very large user group and thus great influence. This study aims to gain a systematic understanding of e-cigarette flavors based on data collected from Reddit. Flavor popularity, mixing, characteristics, trends, and brands are analyzed. Fruit flavors were mentioned the most (n = 15,720) among all the posts and were among the most popular flavors (n = 2902) used in mixed blends. Strawberry and vanilla flavors were the most popular for e-juice mixing. The number of posts discussing e-cigarette flavors has increased sharply since 2014. Mt. Baker Vapor and Hangen were the most popular brands discussed among users. Information posted on Reddit about e-cigarette flavors reflected consumers’ interest in a variety of flavors. Our findings suggest that Reddit could be used for data mining and analysis of e-cigarette-related content. Understanding how e-cigarette consumers’ view and utilize flavors within their vaping experience and how producers and marketers use social media to promote flavors and sell products could provide valuable information for regulatory decision-makers. PMID:26610541

  7. Issues of nanoelectronics: a possible roadmap.

    PubMed

    Wang, Kang L

    2002-01-01

    In this review, we will discuss a possible roadmap in scaling a nanoelectronic device from today's CMOS technology to the ultimate limit when the device fails. In other words, at the limit, CMOS will have a severe short channel effect, significant power dissipation in its quiescent (standby) state, and problems related to other essential characteristics. Efforts to use structures such as the double gate, vertical surround gate, and SOI to improve the gate control have continually been made. Other types of structures using SiGe source/drain, asymmetric Schottky source/drain, and the like will be investigated as viable structures to achieve ultimate CMOS. In reaching its scaling limit, tunneling will be an issue for CMOS. The tunneling current through the gate oxide and between the source and drain will limit the device operation. When tunneling becomes significant, circuits may incorporate tunneling devices with CMOS to further increase the functionality per device count. We will discuss both the top-down and bottom-up approaches in attaining the nanometer scale and eventually the atomic scale. Self-assembly is used as a bottom-up approach. The state of the art is reviewed, and the challenges of the multiple-step processing in using the self-assembly approach are outlined. Another facet of the scaling trend is to decrease the number of electrons in devices, ultimately leading to single electrons. If the size of a single-electron device is scaled in such a way that the Coulomb self-energy is higher than the thermal energy (at room temperature), a single-electron device will be able to operate at room temperature. In principle, the speed of the device will be fast as long as the capacitance of the load is also scaled accordingly. The single-electron device will have a small drive current, and thus the load capacitance, including those of interconnects and fanouts, must be small to achieve a reasonable speed. However, because the increase in the density (and/or functionality) of integrated circuits is the principal driver, the wiring or interconnects will increase and become the bottleneck for the design of future high-density and high-functionality circuits, particularly for single-electron devices. Furthermore, the massive interconnects needed in the architecture used today will result in an increase in load capacitance. Thus for single-electron device circuits, it is critical to have minimal interconnect loads. And new types of architectures with minimal numbers of global interconnects will be needed. Cellular automata, which need only nearest-neighbor interconnects, are discussed as a plausible example. Other architectures such as neural networks are also possible. Examples of signal processing using cellular automata are discussed. Quantum computing and information processing are based on quantum mechanical descriptions of individual particles correlated among each other. A quantum bit or qubit is described as a linear superposition of the wave functions of a two-state system, for example, the spin of a particle. With the interaction of two qubits, they are connected in a "wireless fashion" using wave functions via quantum mechanical interaction, referred to as entanglement. The interconnection by the nonlocality of wave functions affords a massive parallel nature for computing or so-called quantum parallelism. We will describe the potential and solid-state implementations of quantum computing and information, using electron spin and/or nuclear spin in Si and Ge. Group IV elements have a long coherent time and other advantages. The example of using SiGe for g factor engineering will be described.

  8. Electron beam focusing system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  9. Effect of group electronegativity on electron transfer in bis(hydrazine) radical cations.

    PubMed

    Qin, Haimei; Zhong, Xinxin; Si, Yubing; Zhang, Weiwei; Zhao, Yi

    2011-04-14

    The radical cation of 4,10-ditert-butyl-5,9-diisopropyl-4,5,9,10-tetraazatetracyclo[6.2.2.2]-tetradecane (sBI4T(+)), as well as its substituted bis(hydrazine) radical cations, is chosen for the investigation of the electronegativity dependence of its intramolecular electron transfer. To do so, two parameters, reorganization energy and electronic coupling, are calculated with several ab initio approaches. It is found that the electronic couplings decrease with the increase of the group electronegativity while the reorganization energies do not show an explicit dependency. Furthermore, Marcus formula is employed to reveal those effect on the electron transfer rates. The predicted rates of electron transfer generally decrease with increasing group electronegativity, although not monotonically.

  10. Introduction to Small Group Discussion.

    ERIC Educational Resources Information Center

    Millar, Dan Pyle

    To bring educational research into focus with tested classroom practice, this booklet provides an introduction to small group discussion. The theory and research section discusses the importance of small group discussion, characteristics of small group discussions, group attraction based on Maslow's hierarchy of basic human needs, group decision…

  11. Non-Fullerene Electron Acceptors for Use in Organic Solar Cells

    PubMed Central

    2015-01-01

    Conspectus The active layer in a solution processed organic photovoltaic device comprises a light absorbing electron donor semiconductor, typically a polymer, and an electron accepting fullerene acceptor. Although there has been huge effort targeted to optimize the absorbing, energetic, and transport properties of the donor material, fullerenes remain as the exclusive electron acceptor in all high performance devices. Very recently, some new non-fullerene acceptors have been demonstrated to outperform fullerenes in comparative devices. This Account describes this progress, discussing molecular design considerations and the structure–property relationships that are emerging. The motivation to replace fullerene acceptors stems from their synthetic inflexibility, leading to constraints in manipulating frontier energy levels, as well as poor absorption in the solar spectrum range, and an inherent tendency to undergo postfabrication crystallization, resulting in device instability. New acceptors have to address these limitations, providing tunable absorption with high extinction coefficients, thus contributing to device photocurrent. The ability to vary and optimize the lowest unoccupied molecular orbital (LUMO) energy level for a specific donor polymer is also an important requirement, ensuring minimal energy loss on electron transfer and as high an internal voltage as possible. Initially perylene diimide acceptors were evaluated as promising acceptor materials. These electron deficient aromatic molecules can exhibit good electron transport, facilitated by close packed herringbone crystal motifs, and their energy levels can be synthetically tuned. The principal drawback of this class of materials, their tendency to crystallize on too large a length scale for an optimal heterojunction nanostructure, has been shown to be overcome through introduction of conformation twisting through steric effects. This has been primarily achieved by coupling two units together, forming dimers with a large intramolecular twist, which suppresses both nucleation and crystal growth. The generic design concept of rotationally symmetrical aromatic small molecules with extended π orbital delocalization, including polyaromatic hydrocarbons, phthalocyanines, etc., has also provided some excellent small molecule acceptors. In most cases, additional electron withdrawing functionality, such as imide or ester groups, can be incorporated to stabilize the LUMO and improve properties. New calamitic acceptors have been developed, where molecular orbital hybridization of electron rich and poor segments can be judiciously employed to precisely control energy levels. Conformation and intermolecular associations can be controlled by peripheral functionalization leading to optimization of crystallization length scales. In particular, the use of rhodanine end groups, coupled electronically through short bridged aromatic chains, has been a successful strategy, with promising device efficiencies attributed to high lying LUMO energy levels and subsequently large open circuit voltages. PMID:26505279

  12. Interactions between low energy electrons and DNA: a perspective from first-principles simulations

    NASA Astrophysics Data System (ADS)

    Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A.; Gu, Bin

    2017-09-01

    DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation—either photons or swift ions—and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

  13. Interactions between low energy electrons and DNA: a perspective from first-principles simulations.

    PubMed

    Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A; Gu, Bin

    2017-09-27

    DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation-either photons or swift ions-and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

  14. Focus group discussion in built environment qualitative research practice

    NASA Astrophysics Data System (ADS)

    Omar, D.

    2018-02-01

    Focus groups discussion is a useful way in built environment for qualitative research practice. Drawing upon recent reviews of focus group discussion and examples of how focus group discussions have been used by researchers and educators, this paper provides what actually happens in focus group discussion as practiced. There is difference between group of people and topic of interest. This article examines the focus group discussions as practiced in built environment. Thus, there is broad form of focus group discussions as practiced in built environment and the applications are varied.

  15. 75 FR 71188 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... open meeting. SUMMARY: In 1998 the Internal Revenue Service established the Electronic Tax... organized public forum for discussion of electronic tax administration issues in support of the overriding...

  16. 78 FR 32306 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... notice. SUMMARY: An open meeting of the Electronic Tax Administration Advisory Committee (ETAAC) will be conducted via telephone conference call. The ETAAC will discuss recommendations for electronic tax...

  17. 76 FR 12793 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... open meeting. SUMMARY: In 1998 the Internal Revenue Service established the Electronic Tax... organized public forum for discussion of electronic tax administration issues in support of the overriding...

  18. 75 FR 30109 - Open Meeting for the Electronic Tax Administration Advisory Committee (ETAAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service Open Meeting for the Electronic Tax... Open Meeting. SUMMARY: In 1998 the Internal Revenue Service established the Electronic Tax... organized public forum for discussion of electronic tax administration issues in support of the overriding...

  19. The Ins and the Outs of Electronic Publishing.

    ERIC Educational Resources Information Center

    Wills, Mathew; Wills, Gordon

    1996-01-01

    Examines electronic publishing for academic and professional publishers. Discusses benefits of electronic publishing to authors and readers, argues that the hard sell and product-driven mindsets will not work in a customer-focused communications medium, and outlines characteristics of electronic publishing that must be incorporated in successful…

  20. A Case Study in E-Journal Developments: The Scandinavian Position.

    ERIC Educational Resources Information Center

    Joa, Harald

    1997-01-01

    Provides an overview of peer-reviewed scientific and scholarly electronic journals in Scandinavia from a publisher's point of view. Discusses the electronic journals market in Scandinavia, international electronic publishing, the Institute for Scientific Information's Electronic Library Project, the one-stop shopping concept, and copyright and…

  1. Timelike Momenta In Quantum Electrodynamics

    DOE R&D Accomplishments Database

    Brodsky, S. J.; Ting, S. C. C.

    1965-12-01

    In this note we discuss the possibility of studying the quantum electrodynamics of timelike photon propagators in muon or electron pair production by incident high energy muon or electron beams from presently available proton or electron accelerators.

  2. Electron-Driven Processes: From Single Collision Experiments to High-Pressure Discharge Plasmas

    NASA Astrophysics Data System (ADS)

    Becker, Kurt

    2001-10-01

    Plasmas are complex systems which consist of various groups of interacting particles (neutral atoms and molecules in their ground states and in excite states, electrons, and positive and negative ions). In principle, one needs to understand and describe all interactions between these particles in order to model the properties of the plasma and to predict its behavior. However, two-body interactions are often the only processes of relevance and only a subset of all possible collisional interactions are important. The focus of this talk is on collisional and radiative processes in low-temperature plasmas, both at low and high pressures. We will limit the discussion (i) to ionization and dissociation processes in molecular low-pressure plasmas and (ii) to collisional and radiative processes in high-pressure plasmas in rare gases and mixtures of rare gases and N2, O2, and H2. Electron-impact dissociation processes can be divided into dissociative excitation and dissociation into neutral ground-state fragments. Neutral molecular dissociation has only recently received attention from experimentalists and theorists because of the serious difficulties associated with the investigation of these processes. Collisional and radiative processes in high-pressure plasmas provide a fertile environment to the study of interactions that go beyond binary collisions involving ground-state species. Step-wise processes and three-body collisions begin to dominate the behavior of such plasmas. We will discuss examples of such processes as they relate to high-pressure rare gas discharge plasmas. Work supported by NSF, DOE, DARPA, NASA, and ABA Inc.

  3. Transmutation of a heme protein.

    PubMed Central

    Barker, P D; Ferrer, J C; Mylrajan, M; Loehr, T M; Feng, R; Konishi, Y; Funk, W D; MacGillivray, R T; Mauk, A G

    1993-01-01

    Residue Asn57 of bovine liver cytochrome b5 has been replaced with a cysteine residue, and the resulting variant has been isolated from recombinant Escherichia coli as a mixture of four major species: A, BI, BII, and C. A combination of electronic spectroscopy, 1H NMR spectroscopy, resonance Raman spectroscopy, electrospray mass spectrometry, and direct electrochemistry has been used to characterize these four major cytochrome derivatives. The red form A (E(m) = -19 mV) is found to possess a heme group bound covalently through a thioether linkage involving Cys57 and the alpha carbon of the heme 4-vinyl group. Form BI has a covalently bound heme group coupled through a thioether linkage involving the beta carbon of the heme 4-vinyl group. Form BII is similar to BI except that the sulfur involved in the thioether linkage is oxidized to a sulfoxide. The green form C (E(m) = 175 mV) possesses a noncovalently bound prosthetic group with spectroscopic properties characteristic of a chlorin. A mechanism is proposed for the generation of these derivatives, and the implications of these observations for the biosynthesis of cytochrome c and naturally occurring chlorin prosthetic groups are discussed. PMID:8341666

  4. Wigner distributions for an electron

    NASA Astrophysics Data System (ADS)

    Kumar, Narinder; Mondal, Chandan

    2018-06-01

    We study the Wigner distributions for a physical electron, which reveal the multidimensional images of the electron. The physical electron is considered as a composite system of a bare electron and photon. The Wigner distributions for unpolarized, longitudinally polarized and transversely polarized electron are presented in transverse momentum plane as well as in impact-parameter plane. The spin-spin correlations between the bare electron and the physical electron are discussed. We also evaluate all the leading twist generalized transverse momentum distributions (GTMDs) for electron.

  5. Ligational behavior of clioquinol antifungal drug towards Ag(I), Hg(II), Cr(III) and Fe(III) metal ions: Synthesis, spectroscopic, thermal, morphological and antimicrobial studies

    NASA Astrophysics Data System (ADS)

    El-Megharbel, Samy M.; Refat, Moamen S.

    2015-04-01

    This article presents a synthesis, characterization, theoretical and biological (anti-bacterial, and anti-fugal) evaluation studies of Ag(I), Hg(II), Cr(III) and Fe(III) complexes of clioquinol (CQ) drug ligand. Structures of the titled complexes cited herein were discussed using elemental analyses and spectral measurements e.g., IR, 1H NMR, and electronic studies. The results confirmed the formation of the clioquinol complexes by three molar ratios (1:1) for Ag(I), (1:2) for Hg(II) and (1:3) for both Cr(III) and Fe(III) metal ions. The clioquinol reacts as a bidentate chelate bound to all respected metal ions through the oxygen and nitrogen of quinoline-8-ol. The metal(II) ions coordinated to clioquinol ligand through deprotonation of sbnd OH terminal group. Infrared and 1H NMR spectral data confirm that coordination is via the oxygen of phenolic group and nitrogen atom of quinoline moiety. The molar conductance measurements of the CQ complexes in DMSO correspond to be non-electrolyte nature. Thus, these complexes may be formulated as [Ag(CQ)(H2O)2] H2O, [Hg(CQ)2]ṡ2H2O, [Cr(CQ)3] and [Fe(CQ)3]H2O. The Coats-Redfern method, the kinetic thermodynamic parameters like activation energies (E∗), entropies (ΔS∗), enthalpies (ΔH∗), and Gibbs free energies (ΔG∗) of the thermal decomposition reactions have been deduced from thermogravimetric curves (TG) with helpful of differential thermo gravimetric (DTG) curves. The narrow size distribution in nano-scale range for the clioquinol complexes have been discussed using X-ray powder diffraction (XRD), scanning electron microscope (SEM), and X-ray energy dispersive spectrometer (EDX) analyzer.

  6. The Use of Electronic Question and Answer Forums in Mathematics Teacher Education

    ERIC Educational Resources Information Center

    Schuck, Sandra

    2003-01-01

    Many mathematics educators share a view of mathematics as a social and cultural phenomenon and believe that the learning of mathematics concepts is developed and enhanced through the use of learning communities. Electronic discussion boards provide one avenue for supporting such social learning. This paper discusses the use of a Question and…

  7. This May Be a Feud, but It Is Not a War: An Electronic, Interdisciplinary Dialogue on Teaching Native Religions.

    ERIC Educational Resources Information Center

    Grimes, Ronald L.

    1996-01-01

    Describes an electronic discussion on three listservs about whether European Americans should teach courses on Native religions; if not, what would result; if so, how to proceed. Responses discuss issues of cultural imperialism and appropriation, academic freedom, cultural property rights and control, qualifications (and disqualifications) for…

  8. Extending the Borders of Community and Learning with Electronic Mail Discussion Lists.

    ERIC Educational Resources Information Center

    Yungbluth, Stephen C.; Bertino, Sissy

    A qualitative study determined the impact electronic mail (e-mail) discussion lists can have on a college classroom. The theoretical concepts explored are "community" and "roles." Community is defined by the boundaries it possesses, the dialogue exchanged, and the people interacting in the community. Roles may be defined by the interactions among…

  9. Reflections and Conclusions on the Work Developed by the Group of Teaching Innovation in Electronics at the University of Valladolid

    ERIC Educational Resources Information Center

    Herrero, Luis Carlos; Pardo, Fernando; Fernando, María Luisa; González, María Luisa

    2011-01-01

    We hereby present the main conclusions and perspectives obtained by the Group of Teaching Innovation in Electronics (Grupo de Innovación Docente en Electrónica, GIDEN) of the University of Valladolid (UVa) with regard to its main areas of work. This group comprises teachers of the "Specialty in Industrial Electronics" degree, and the…

  10. Quantum Computational Studies of Electron Transfer in Respiratory Complex III and its Application for Designing New Mitocan Drugs

    NASA Astrophysics Data System (ADS)

    Hagras, Muhammad Ahmed

    Electron transfer occurs in many biological systems which are imperative to sustain life; oxidative phosphorylation in prokaryotes and eukaryotes, and photophosphorylation in photosynthetic and plant cells are well-balanced and complementary processes. Investigating electron transfer in those natural systems provides detailed knowledge of the atomistic events that lead eventually to production of ATP, or harvesting light energy. Ubiquinol:cytochrome c oxidoreductase complex (also known as bc 1 complex, or respiratory complex III) is a middle player in the electron transport proton pumping orchestra, located in the inner-mitochondrial membrane in eukaryotes or plasma membrane in prokaryotes, which converts the free energy of redox reactions to electrochemical proton gradient across the membrane, following the fundamental chemiosmotic principle discovered by Peter Mitchell 1. In humans, the malfunctioned bc1 complex plays a major role in many neurodegenerative diseases, stress-induced aging, and cancer development, because it produces most of the reactive oxygen species, which are also involved in cellular signaling 2. The mitochondrial bc1 complex has an intertwined dimeric structure comprised of 11 subunits in each monomer, but only three of them have catalytic function, and those are the only domains found in bacterial bc1 complex. The core subunits include: Rieske domain, which incorporates iron-sulfur cluster [2Fe-2S]; trans-membrane cytochrome b domain, incorporating low-potential heme group (heme b L) and high-potential heme group (heme b H); and cytochrome c1 domain, containing heme c1 group and two separate binding sites, Qo (or QP) site where the hydrophobic electron carrier ubihydroquinol QH2 is oxidized, and Qi (or QN) site where ubiquinone molecule Q is reduced 3. Electrons and protons in the bc1 complex flow according to the proton-motive Q-cycle proposed by Mitchell, which includes a unique electron flow bifurcation at the Qo site. At this site, one electron of a bound QH2 molecule transfers to [2Fe-2S] cluster of the Rieske domain, docked at the proximal docking site, and another electron transfers to heme b L , which subsequently passes it to heme bH , and finally to Q or SQ molecule bound at the Qi-site 4. Rieske domain undergoes a domain movement 22 A to bind at the distal docking site, where [2Fe-2S] cluster passes its electron to heme c1, which in turn passes it to heme c of the water-soluble cytochrome c carrier 3c, 5 (which shuttles it to cytochrome c oxidase, complex IV). In the current compiled work presented in the subsequent chapters, we deployed a stacking tiers hierarchy where each chapter's work presents a foundation for the next one. In chapter 1, we first present different methods to calculate tunneling currents in proteins including a new derivation method for the inter-atomic tunneling current method. In addition, we show the results of the inter-atomic tunneling current theory on models based on heme bL-heme bH redox pair system in bc1 complex. Afterwards, in chapter 2, we examine the electron tunneling pathways 6 between different intra-monomeric and inter-monomeric redox centers of bc1 complex, including its electron carriers - ubiquinol, ubiquinone, and cytochrome c molecules, using the well-studied coarse-grained interatomic method of the tunneling current theory 7. Going through the different tunneling pathways in bc1 complex, we discovered a pair of internal switches that modulate the electron transfer rate which we discuss in full details in chapter 3. Motivated by the discovery of those internal switches, we discuss in chapter 4 the discovery of a new binding pocket (designated as NonQ-site or NQ-site for short) in bc 1 complex which is located at the opposite side of the enzyme with respect to Qo site. In contrast to Qo site, however, the NQ-site penetrates deeply in the cytochrome b domain and reaches very closely the LH region. Hence the NQ-site provides a suitable binding pocket for ligands that can influence the orientation of Phe90 residue, and hence modulate the corresponding ET rate between heme b L and heme bH. Finally we present in chapter 5 our unique integrated software package (called Electron Tunneling in Proteins Program or ETP) which provides an environment with different capabilities such as tunneling current calculation, semi-empirical quantum mechanical calculation and molecular modeling simulation for calculation and analysis of electron transfer reactions in proteins.

  11. The Future of Consortia among Indian Libraries --- FORSA Consortium as Forerunner?

    NASA Astrophysics Data System (ADS)

    Birdie, Christina; Alladi, Vagiswari

    The phenomenon of consortia or group of libraries buying e-information together has become very important in the last few years. This new scenario, along with new forms of purchasing and selling e-information, has led to new pricing models that have not yet been fixed. Publishers and vendors find it convenient to communicate to a group collectively rather than transacting with individual libraries. In this paper we discuss the various offers from different publishers for access to electronic journals. We also attempt to analyze the suitability of these offers for the future of consortia arrangement in libraries in India based on the requirement and usage of digital information. Some of the challenges could be sorted out with the help of governments' participation in bridging the Digital Divide within the country more economically.

  12. Average thermal characteristics of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Montgomery, M. D.

    1972-01-01

    Average solar wind electron properties based on a 1 year Vela 4 data sample-from May 1967 to May 1968 are presented. Frequency distributions of electron-to-ion temperature ratio, electron thermal anisotropy, and thermal energy flux are presented. The resulting evidence concerning heat transport in the solar wind is discussed.

  13. SOME PROBLEMS IN THE CONSTRUCTION OF AN ELECTRON LINEAR ACCELERATOR (in Dutch)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Verhaeghe, J.; Vanhuyse, V.; Van Leuven, P.

    1959-01-01

    Special problems encountered in the construction of the electron linear accelerator of the Natuurkundig Laboratorium der Rijksuniversiteit of Ghent are discussed. The subjects considered are magnetic focusing, magnetic screening of the electron gun cathode, abnormal attenuation-multipactor effects, and electron energy control. (J.S.R.)

  14. The Internet and Technical Services: A Point Break Approach.

    ERIC Educational Resources Information Center

    McCombs, Gillian M.

    1994-01-01

    Discusses implications of using the Internet for library technical services. Topics addressed include creative uses of the Internet; three basic applications on the Internet, i.e., electronic mail, remote log-in to another computer, and file transfer; electronic processing of information; electronic access to information; and electronic processing…

  15. Molecular Diode Studies Based on a Highly Sensitive Molecular Measurement Technique.

    PubMed

    Iwane, Madoka; Fujii, Shintaro; Kiguchi, Manabu

    2017-04-26

    In 1974, molecular electronics pioneers Mark Ratner and Arieh Aviram predicted that a single molecule could act as a diode, in which electronic current can be rectified. The electronic rectification property of the diode is one of basic functions of electronic components and since then, the molecular diode has been investigated as a first single-molecule device that would have a practical application. In this review, we first describe the experimental fabrication and electronic characterization techniques of molecular diodes consisting of a small number of molecules or a single molecule. Then, two main mechanisms of the rectification property of the molecular diode are discussed. Finally, representative results for the molecular diode are reviewed and a brief outlook on crucial issues that need to be addressed in future research is discussed.

  16. Molecular Diode Studies Based on a Highly Sensitive Molecular Measurement Technique

    PubMed Central

    Iwane, Madoka; Fujii, Shintaro; Kiguchi, Manabu

    2017-01-01

    In 1974, molecular electronics pioneers Mark Ratner and Arieh Aviram predicted that a single molecule could act as a diode, in which electronic current can be rectified. The electronic rectification property of the diode is one of basic functions of electronic components and since then, the molecular diode has been investigated as a first single-molecule device that would have a practical application. In this review, we first describe the experimental fabrication and electronic characterization techniques of molecular diodes consisting of a small number of molecules or a single molecule. Then, two main mechanisms of the rectification property of the molecular diode are discussed. Finally, representative results for the molecular diode are reviewed and a brief outlook on crucial issues that need to be addressed in future research is discussed. PMID:28445393

  17. Problems related to the integration of fault tolerant aircraft electronic systems

    NASA Technical Reports Server (NTRS)

    Bannister, J. A.; Adlakha, V.; Triyedi, K.; Alspaugh, T. A., Jr.

    1982-01-01

    Problems related to the design of the hardware for an integrated aircraft electronic system are considered. Taxonomies of concurrent systems are reviewed and a new taxonomy is proposed. An informal methodology intended to identify feasible regions of the taxonomic design space is described. Specific tools are recommended for use in the methodology. Based on the methodology, a preliminary strawman integrated fault tolerant aircraft electronic system is proposed. Next, problems related to the programming and control of inegrated aircraft electronic systems are discussed. Issues of system resource management, including the scheduling and allocation of real time periodic tasks in a multiprocessor environment, are treated in detail. The role of software design in integrated fault tolerant aircraft electronic systems is discussed. Conclusions and recommendations for further work are included.

  18. Electron Spectroscopic Methods in Teaching.

    ERIC Educational Resources Information Center

    Allan, Michael

    1987-01-01

    Discusses electron-loss spectroscopy and the experimentally observed excitation energies in terms of qualitative MO theory. Reviews information on photoelectron spectroscopy and electron transmission spectroscopy and their relation to the occupied and unoccupied orbital levels. Focuses on teaching applications. (ML)

  19. The characteristics of a possible low altitude electron layer in the Martian atmosphere. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Wallio, H. A.

    1973-01-01

    The apparent diurnal Martian surface pressure variation, as deduced from radio occultation experiments, is discussed and explained as possibly arising from the effect of a low altitude electron layer. Possible source and loss mechanisms for the low altitude electron layer are presented and discussed. Time-dependent differential equations describing the electron layer are derived and then integrated to investigate the electron distribution resulting from the several processes that might occur in the atmosphere. It is concluded that the source mechanism is the sublimation of alkali atoms from a permanent dust layer (a dust layer of 0.2 micron particles of density 9/cu cm is sufficient), and that the dominant loss process must involve CO2 clustering to the alkali atoms. Using these processes, an electron layer is developed which would explain the apparent diurnal surface pressure.

  20. Interference with electrons: from thought to real experiments

    NASA Astrophysics Data System (ADS)

    Matteucci, Giorgio

    2013-11-01

    The two-slit interference experiment is usually adopted to discuss the superposition principle applied to radiation and to show the peculiar wave behaviour of material particles. Diffraction and interference of electrons have been demonstrated using, as interferometry devices, a hole, a slit, double hole, two-slits, an electrostatic biprism etc. A number of books, short movies and lectures on the web try to popularize the mysterious behaviour of electrons on the basis of Feynman thought experiment which consists of a Young two-hole interferometer equipped with a detector to reveal single electrons. A short review is reported regarding, i) the pioneering attempts carried out to demonstrate that interference patterns could be obtained with single electrons through an interferometer and, ii) recent experiments, which can be considered as the realization of the thought electron interference experiments adopted by Einstein-Bohr and subsequently by Feynman to discuss key features of quantum physics.

  1. Low-energy Auger electron diffraction: influence of multiple scattering and angular momentum

    NASA Astrophysics Data System (ADS)

    Chassé, A.; Niebergall, L.; Kucherenko, Yu.

    2002-04-01

    The angular dependence of Auger electrons excited from single-crystal surfaces is treated theoretically within a multiple-scattering cluster model taking into account the full Auger transition matrix elements. In particular the model has been used to discuss the influence of multiple scattering and angular momentum of the Auger electron wave on Auger electron diffraction (AED) patterns in the region of low kinetic energies. Theoretical results of AED patterns are shown and discussed in detail for Cu(0 0 1) and Ni(0 0 1) surfaces, respectively. Even though Cu and Ni are very similar in their electronic and scattering properties recently strong differences have been found in AED patterns measured in the low-energy region. It is shown that the differences may be caused to superposition of different electron diffraction effects in an energy-integrated experiment. A good agreement between available experimental and theoretical results has been achieved.

  2. Two-photon or higher-order absorbing optical materials for generation of reactive species

    NASA Technical Reports Server (NTRS)

    Marder, Seth R. (Inventor); Cumpston, Brian (Inventor); Lipson, Matthew (Inventor); Perry, Joseph W. (Inventor)

    2003-01-01

    Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed.

  3. Two-photon or higher-order absorbing optical materials for generation of reactive species

    NASA Technical Reports Server (NTRS)

    Perry, Joseph W (Inventor); Cumpston, Brian (Inventor); Lipson, Matthew (Inventor); Marder, Seth R (Inventor)

    2007-01-01

    Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed.

  4. Two-Photon or Higher-Order Absorbing Optical Materials for Generation of Reactive Species

    NASA Technical Reports Server (NTRS)

    Perry, Joseph W. (Inventor); Cumpston, Brian (Inventor); Lipson, Matthew (Inventor); Marder, Seth R. (Inventor)

    2013-01-01

    Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed.

  5. Quantum Hall Valley Nematics: From Field Theories to Microscopic Models

    NASA Astrophysics Data System (ADS)

    Parameswaran, Siddharth

    The interplay between quantum Hall ordering and spontaneously broken ``internal'' symmetries in two-dimensional electron systems with spin or pseudospin degrees of freedom gives rise to a variety of interesting phenomena, including novel phases, phase transitions, and topological excitations. I will discuss a theory of broken-symmetry quantum Hall states, applicable to a class of multivalley systems, where the symmetry at issue is a point-group element that combines a spatial rotation with a permutation of valley indices. I will explore its ramifications for the phase diagram of a variety of experimental systems, such as AlAs and Si quantum wells and the surface states of bismuth. I will also discuss unconventional transport phenomena in these phases in the presence of quenched randomness, and the possible mechanisms of selection between degenerate broken-symmetry phases in clean systems. I acknowledge support from NSF DMR-1455366.

  6. Status epilepticus in the elderly: epidemiology, clinical aspects and treatment

    PubMed Central

    de Assis, Telma M.R.; Costa, Gersonita; Bacellar, Aroldo; Orsini, Marco; Nascimento, Osvaldo J.M.

    2012-01-01

    The aim of the study was to review the epidemiology, clinical profile and discuss the etiology, prognosis and treatment options in patients aged 60 years or older presenting with status epilepticus. We performed a systematic review involving studies published from 1996 to 2010, in Medline/PubMed, Scientific Electronic Library on line (Scielo), Latin-American and Caribbean Center of Health Sciences Information (Lilacs) databases and textbooks. Related articles published before 1996, when relevant for discussing epilepsy in older people, were also included. Several population studies had shown an increased incidence of status epilepticus after the age of 60 years. Status epilepticus is a medical and neurological emergency that is associated with high morbidity and mortality, and is a major concern in the elderly compared to the general population. Prompt diagnosis and effective treatment of convulsive status epilepticus are crucial to avoid brain injury and reduce the fatality rate in this age group. PMID:23355930

  7. Toward operation of series IDs at BL43LXU of SPring-8

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baron, A. Q. R.; Tanaka, T.; Soutome, K.

    2016-07-27

    This paper discusses two issues relating to using 3 small gap insertion devices in series at BL43LXU of SPring-8 to make a uniquely powerful source in the 15-26 keV region of the x-ray spectrum. The issues discussed are (1) damage to the covers of the downstream IDs by radiation from the upstream IDs and (2) proper steering of the electron beam to get the best photon beam properties. After tests in several configurations, including one where an ID was run without an impedance-reducing cover, the damage issue was solved by installing a distributed absorber in the most downstream ID. Themore » steering issues were mostly resolved by the introduction of appropriate corrector magnets and feedback. The paper is written from the viewpoint of an interested beamline scientist impressed with the cooperation of different groups to make a source for new science possible.« less

  8. Properties that influence the specific surface areas of carbon nanotubes and nanofibers.

    PubMed

    Birch, M Eileen; Ruda-Eberenz, Toni A; Chai, Ming; Andrews, Ronnee; Hatfield, Randal L

    2013-11-01

    Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer-Emmett-Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

  9. The design of electron and ion guns, beams, and collectors

    NASA Astrophysics Data System (ADS)

    Becker, Reinard; Herrmannsfeldt, William B.

    2004-01-01

    The well known `SLAC Electron Trajectory Program' (EGUN) has been ported to PCs and has been developed into a family of programs for the design and the optimization of particle optics devices including electron and ion guns, beam transport sections and collectors. We will discuss the application of these tools for the design and the optimization of the essential parts of EBIS/T devices. The discussion will include conditions in which restrictions in the reliability of simulations may occur due to the mathematical modeling and how to overcome them.

  10. Trends in solid state electronics, part 2

    NASA Technical Reports Server (NTRS)

    Gassaway, J. D.

    1972-01-01

    Developments in the fields of semiconductors and magnetics are surveyed. Materials, devices, theory, and fabrication technology are discussed. Important events up until the present time are reported, and events are interpreted through historical perspective. A brief analysis of forces which have driven the development of today's electronic technology and some projections of present trends are given. More detailed discussions are presented for four areas of contemporary interest: amorphous semiconductors, bubble domain devices, charge-coupled devices, and electron and ion beam techniques. Beam addressed magnetic memories are reviewed to a lesser extent.

  11. The information needs and information seeking behaviour of family doctors.

    PubMed

    Bryant, Sue Lacey

    2004-06-01

    To explore the information needs and information seeking behaviour of family doctors, identifying any differences in attitudes and behaviours deriving from membership of a training practice and investigating the impact of a practice librarian. A case study of general practitioners (GPs) in Aylesbury Vale incorporated a quantitative study of use of the medical library, and two qualitative techniques, in-depth interviews and group discussions. A total of 58 GPs, almost three quarters of those in the Vale, participated; 19 via individual interviews and a further 39 via two group discussions. Family doctors are prompted to seek information by needs arising from a combination of professional responsibilities and personal characteristics. A need for problem-orientated information, related to the care of individual patients, was the predominant factor that prompted these GPs to seek information. Personal collections remain the preferred information resource; electronic sources rank second. The study demonstrated low use of the medical library. However, both vocational training and the employment of a practice librarian impacted on library use. The study illuminates the information needs and preferences of GPs and illustrates the contribution that librarians may make at practice level, indicating the importance of outreach work.

  12. Patients' willingness to pay for electronic communication with their general practitioner.

    PubMed

    Bergmo, Trine Strand; Wangberg, Silje Camilla

    2007-06-01

    Despite the common use of electronic communication in other aspects of everyday life, its use between patients and health care providers has been slow to diffuse. Possible explanations are security issues and lack of payment mechanisms. This study investigated how patients value secure electronic access to their general practitioner (GP). One hundred and ninety-nine patients were asked an open-ended willingness-to-pay (WTP) question as part of a randomised controlled trial. We compared the WTP values between two groups of respondents; one group had had the opportunity to communicate electronically with their GP for a year and the other group had not. Fifty-two percent of the total sample was willing to pay for electronic GP contact. The group of patients with access revealed a significantly lower WTP than the group without such access. Possible explanations are that the system had fewer benefits than expected, a presence of hypothetical bias or simply a preference for face-to-face encounters.

  13. High-Energy Electron-Induced SEUs and Jovian Environment Impact

    NASA Astrophysics Data System (ADS)

    Tali, Maris; Alía, Rubén García; Brugger, Markus; Ferlet-Cavrois, Veronique; Corsini, Roberto; Farabolini, Wilfrid; Mohammadzadeh, Ali; Santin, Giovanni; Virtanen, Ari

    2017-08-01

    We present experimental evidence of electron-induced upsets in a reference European Space Agency (ESA) single event upset (SEU) monitor, induced by a 200-MeV electron beam at the Very energetic Electronic facility for Space Planetary Exploration in harsh Radiation environments facility at CERN. Comparison of experimental cross sections and simulated cross sections is shown and the differences are analyzed. Possible secondary contributions to the upset rate by neutrons, flash effects, and cumulative dose effects are discussed, showing that electronuclear reactions are the expected SEU mechanism. The ESA Jupiter Icy Moons Explorer mission, to be launched in 2022, presents a challenging radiation environment due to the intense high-energy electron flux in the trapped radiation belts. Insight is given to the possible contribution of electrons to the overall upset rates in the Jovian radiation environment. Relative contributions of both typical electron and proton spectra created when the environmental spectra are transported through a typical spacecraft shielding are shown and the different mission phases are discussed.

  14. Low-Temperature Spacecraft: Challenges/Opportunities

    NASA Technical Reports Server (NTRS)

    Dickman, J. E.; Patterson, R. L.; Overton, E.; Hammoud, A. N.; Gerber, S. S.

    2001-01-01

    Imagine sending a spacecraft into deep space that operates at the ambient temperature of its environment rather than hundreds of degrees Kelvin warmer. The average temperature of a spacecraft warmed only by the sun drops from 279 K near the Earth's orbit to 90 K near the orbit of Saturn, and to 44 K near Pluto's orbit. At present, deep space probes struggle to maintain an operating temperature near 300 K for the onboard electronics. To warm the electronics without consuming vast amounts of electrical energy, radioisotope heater units (RHUs) are used in vast numbers. Unfortunately, since RHU are always 'on', an active thermal management system is required to reject the excess heat. A spacecraft designed to operate at cryogenic temperatures and shielded from the sun by a large communication dish or solar cell array could be less complex, lighter, and cheaper than current deep space probes. Before a complete low-temperature spacecraft becomes a reality, there are several challenges to be met. Reliable cryogenic power electronics is one of the major challenges. The Low-Temperature Power Electronics Research Group at NASA Glenn Research Center (GRC) has demonstrated the ability of some commercial off the shelf power electronic components to operate at temperatures approaching that of liquid nitrogen (77 K). Below 77 K, there exists an opportunity for the development of reliable semiconductor power switching technologies other than bulk silicon CMOS. This paper will report on the results of NASA GRC's Low-Temperature Power Electronics Program and discuss the challenges to (opportunities for) the creation of a low-temperature spacecraft.

  15. Analysis of urine composition in type Ⅱ diabetic mice after intervention therapy using holothurian polypeptides

    NASA Astrophysics Data System (ADS)

    Li, Yanyan; Xu, Jiajie; Su, Xiurong

    2017-07-01

    Hydrolysates and peptide fractions (PF) obtained from sea cucumber with commercial enzyme were studied on the hpyerglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR), and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of holothurian polypeptides treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

  16. Chalcones: structural requirements for antioxidant, estrogenic and antiproliferative activities.

    PubMed

    Calliste, C A; Le Bail, J C; Trouillas, P; Pouget, C; Habrioux, G; Chulia, A J; Duroux, J L

    2001-01-01

    Flavonoids are largely studied for their biological properties and particularly for their scavenging and antioxidant activities. In the present study, we first evaluated the antioxidant and the estrogenic actions of chalcones, then we tested their effects on MCF-7 cell proliferation. Chalcones are unique in the flavonoids family in lacking a heterocyclic C ring. We tested substituted chalcones with different numbers and different positions of the hydroxy groups: 2'-hydroxychalcone, 4'-hydroxychalcone, 4-hydroxychalcone, 2',4-dihydroxychalcone, isoliquiritigenin, 2',4'-dihydroxychalcone, phloretin and naringenin chalcone. For the antioxidant tests we established the importance of the alpha-beta double bond and the 6'-hydroxy group. The establishment of the structure-activity relationship for the estrogenic properties showed a correlation between the antioxidant and the estrogenic properties. The importance of conformation and hydroxy group positions observed for chalcones, having antioxidant and estrogenic properties, was also observed on MCF-7 cell growth with the same structure-activity relationship. The role of electron and hydrogen transfer in the correlation between these three biological activities was discussed.

  17. The Lewis Electron-Pair Model, Spectroscopy, and the Role of the Orbital Picture in Describing the Electronic Sructure of Molecules.

    ERIC Educational Resources Information Center

    Gallup, G. A.

    1988-01-01

    Describes why specific forms of orbitals used to interpret spectroscopy involving electronic transitions may not say much about the electronic structure of molecules. Discusses several theoretical approaches to explain the anomoly. Determines that the Lewis electron-pair model for molecules is a good predictor of spectroscopic results. (ML)

  18. Self-Consistent Superthermal Electron Effects on Plasmaspheric Refilling

    NASA Technical Reports Server (NTRS)

    Liemohn, M. W.; Khazanov, G. V.; Moore, T. E.; Guiter, S. M.

    1997-01-01

    The effects of self-consistently including superthermal electrons in the definition of the ambipolar electric field are investigated for the case of plasmaspheric refilling after a geomagnetic storm. By using the total electron population in the hydrodynamic equations, a method for incorporating superthermal electron parameters in the electric field and electron temperature calculation is developed. Also, the ambipolar electric field is included in the kinetic equation for the superthermal electrons through a change of variables using the total energy and the first adiabatic invariant. Calculations based on these changes are performed by coupling time-dependent models of the thermal plasma and superthermal electrons. Results from this treatment of the electric field and the self-consistent development of the solution are discussed in detail. Specifically, there is a decreased thermal electron density in the plasmasphere during the first few minutes of refilling, a slightly accelerated proton shock front, and a decreased superthermal electron flux due to the deceleration by the electric field. The timescales of plasmaspheric refilling are discussed and determined to be somewhat shorter than previously calculated for the thermal plasma and superthermal electron population due to the effects of the field-aligned potential.

  19. Symmetry properties of the electron density and following from it limits on the KS-DFT applications

    NASA Astrophysics Data System (ADS)

    Kaplan, Ilya G.

    2018-03-01

    At present, the Density Functional Theory (DFT) approach elaborated by Kohn with co-authors more than 50 years ago became the most widely used method for study molecules and solids. Using modern computation facilities, it can be applied to systems with million atoms. In the atmosphere of such great popularity, it is particularly important to know the limits of the applicability of DFT methods. In this report, I will discuss two cases when the conventional DFT approaches, using only electron density ρ and its gradients, cannot be applied (I will not consider the Ψ-versions of DFT). The first case is quite evident. In the degenerated states, the electron density may not be defined, since electronic and nuclear motions cannot be separated, the vibronic interaction mixed them. The second case is related to the spin of the state. As it was rigorously proved by group theoretical methods at the theorem level, the electron density does not depend on the total spin S of the arbitrary N-electron state. It means that the Kohn-Sham equations have the same form for states with different S. The critical survey of elaborated DFT procedures, taking into account spin, shows that they modified only exchange functionals, the correlation functionals do not correspond to the spin of the state. The point is that the conception of spin cannot be defined in the framework of the electron density formalism, which corresponds to the one-particle reduced density matrix. This is the main reason of the problems arising in the study by DFT of magnetic properties of the transition metals. The possible way of resolving these problems can be found in the two-particle reduced density matrix formulation of DFT.

  20. Electron Bubbles in Superfluid (3) 3 He-A: Exploring the Quasiparticle-Ion Interaction

    NASA Astrophysics Data System (ADS)

    Shevtsov, Oleksii; Sauls, J. A.

    2017-06-01

    When an electron is forced into liquid ^3He, it forms an "electron bubble", a heavy ion with radius, R˜eq 1.5 nm, and mass, M˜eq 100 m_3, where m_3 is the mass of a ^3He atom. These negative ions have proven to be powerful local probes of the physical properties of the host quantum fluid, especially the excitation spectra of the superfluid phases. We recently developed a theory for Bogoliubov quasiparticles scattering off electron bubbles embedded in a chiral superfluid that provides a detailed understanding of the spectrum of Weyl Fermions bound to the negative ion, as well as a theory for the forces on moving electron bubbles in superfluid ^3He-A (Shevtsov and Sauls in Phys Rev B 94:064511, 2016). This theory is shown to provide quantitative agreement with measurements reported by the RIKEN group (Ikegami et al. in Science 341(6141):59, 2013) for the drag force and anomalous Hall effect of moving electron bubbles in superfluid ^3He-A. In this report, we discuss the sensitivity of the forces on the moving ion to the effective interaction between normal-state quasiparticles and the ion. We consider models for the quasiparticle-ion (QP-ion) interaction, including the hard-sphere potential, constrained random-phase-shifts, and interactions with short-range repulsion and intermediate-range attraction. Our results show that the transverse force responsible for the anomalous Hall effect is particularly sensitive to the structure of the QP-ion potential and that strong short-range repulsion, captured by the hard-sphere potential, provides an accurate model for computing the forces acting on the moving electron bubble in superfluid 3He-A.

  1. Age-related trends in utilization of the internet and electronic communication devices for coordination of cancer care in elderly patients.

    PubMed

    Saied, Abdul; Sherry, Steven J; Castricone, Donna J; Perry, Kathleen M; Katz, Steven C; Somasundar, Ponnandai

    2014-04-01

    In this rapidly changing electronic era, we implemented a study to define age dependent variations in access and use of internet and electronic devices in the exchange of healthcare related information (HRI) and coordination of clinical care (CCC) among elderly patients with cancer. Data was collected through independently completed surveys after obtaining IRB approval in a single institution cancer center over a 4-month period. Questions regarding internet access and use of electronic media to obtain health information and coordinate care were distributed. The sample was divided in two groups based upon the World Health Organization (WHO) definition of geriatric patients: <65 y/o (group A) and ≥65 y/o (group B). One hundred and twenty-six surveys were analyzed with 70 patients in group A and 56 patients in group B. Access to the internet and use of email was higher in the group A (77% and 71%) vs. group B (36% and 33%, p < 0.001). The younger group felt more comfortable using the internet when compared to the older group (70% vs. 40%, p = 0.01). Patients in group B demonstrated a strong preference for paper copy based HRI and phone calls to CCC than text messages or emails (73% and 95%, p < 0.001). A transition zone between the ages of 65 and 70 years was defined to identify patients with increased reluctance to use internet and electronic devices to exchange HRI and CCC. The data supports that there is an age-defined underutilization of internet and electronic devices to exchange HRI and CCC. Characterization of this age-dependent transition zone will enable clinicians to identify patients who may not interface well with electronic communication strategies, and to improve delivery of HRI and CCC for the elderly. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  2. Prototype electron lens set-up for the Tevatron beam-beam compensation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Crawford, C.; Saewert, G.; Santucci, J.

    1999-05-17

    A prototype "electron lens" for the Tevatron beam-beam compensation project is commissioned at Fermilab. We de-scribe the set-up, report results of the first tests of the elec-tron beam, and discuss future plans.

  3. Neal-Schuman Electronic Classroom Handbook.

    ERIC Educational Resources Information Center

    Hinchliffe, Lisa Janicke

    This book discusses planning, designing, and implementing electronic classrooms. Chapters cover: (1) background, including the definition of electronic classrooms, classroom types, and justifications; (2) planning, including planners and the planning process; (3) gathering and analyzing information, including instructional needs assessment,…

  4. Developments in electron gun simulation

    NASA Astrophysics Data System (ADS)

    Herrmannsfeldt, W. B.

    1997-01-01

    This paper will discuss the developments in the electron gun simulation programs that are based on EGUN and its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications on EGN2 of this evolution will be discussed. Some examples and a review of the capabilities of the EGUN family will be described.

  5. Developments in the electron gun simulation program, EGUN

    NASA Astrophysics Data System (ADS)

    Herrmannsfeldt, W. B.

    1994-11-01

    This paper discusses the developments in the electron gun simulation programs that are based on EGUN with its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications of this evolution on EGN2 are discussed. Some examples and a review of the capabilities of the EGUN family are described.

  6. Developments in the electron gun simulation program, EGUN

    NASA Astrophysics Data System (ADS)

    Herrmannsfeldt, W. B.

    1995-07-01

    This paper discusses the developments in the electron gun simulation programs that are based on EGUN with its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications of this evolution on EGN2 are discussed. Some examples and a review of the capabilities of the EGUN family are described.

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

    ERIC Educational Resources Information Center

    Fisch, Audrey A.; Bennett, Deborah J.

    2011-01-01

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

  8. Electronic and Optical Sources of Information for the Humanities: A Survey of Library Users, Products and Projects in Italy.

    ERIC Educational Resources Information Center

    Paci, Augusta Maria; And Others

    1990-01-01

    Discussion of electronic information products for the humanities focuses on users in Italy. Databases are discussed; a user survey of La Sapienza University Arts Faculty is described; an example of research using two databases, FRANCIS and Philosopher's Index, is given; and Italian products and projects for the humanities are reviewed. (15…

  9. Focused electron beam induced deposition of pure SIO II

    NASA Astrophysics Data System (ADS)

    Perentes, Alexandre; Hoffmann, Patrik; Munnik, Frans

    2007-02-01

    Focused electron beam induced processing (FEBID) equipments are the "all in one" tools for high resolution investigation, and modification of nano-devices. Focused electron beam induced deposition from a gaseous precursor usually results in a nano-composite sub-structured material, in which the interesting material is embedded in an amorphous carbonaceous matrix. Using the Hydrogen free tetraisocyanatosilane Si(NCO) 4 molecule as Si source, we show how a controlled oxygen flux, simultaneously injected with the precursor vapors, causes contaminants to vanish from the FEB deposits obtained and leads to the deposition of pure SiO II. The chemical composition of the FEBID material could be controlled from SiC IINO 3 to SiO II, the latter containing undetectable foreign element contamination. The [O II] / [TICS] ratio needed to obtain SiO II in our FEB deposition equipment is larger than 300. The evolution of the FEBID material chemical composition is presented as function of the [O II] / [TICS] molecular flux ratios. A hypothetical decomposition pathway of this silane under these conditions is discussed based on the different species formed under electron bombardment of TICS. Transmission electron microscopy investigations demonstrated that the deposited oxide is smooth (roughness sub 2nm) and amorphous. Infrared spectroscopy confirmed the low concentration of hydroxyl groups. The Hydrogen content of the deposited oxide, measured by elastic recoil detection analysis, is as low as 1 at%. 193nm wavelength AIMS investigations of 125nm thick SiO II pads (obtained with [O II] / [TICS] = 325) showed an undetectable light absorption.

  10. Management of simulated maternal cardiac arrest by residents: didactic teaching versus electronic learning.

    PubMed

    Hards, Andrea; Davies, Sharon; Salman, Aliya; Erik-Soussi, Magda; Balki, Mrinalini

    2012-09-01

    Successful resuscitation of a pregnant woman undergoing cardiac arrest and survival of the fetus require prompt, high-quality cardiopulmonary resuscitation. The objective of this observational study was to assess management of maternal cardiac arrest by anesthesia residents using high-fidelity simulation and compare subsequent performance following either didactic teaching or electronic learning (e-learning). Twenty anesthesia residents were randomized to receive either didactic teaching (Didactic group, n = 10) or e-learning (Electronic group, n = 10) on maternal cardiac arrest. Baseline management skills were tested using high-fidelity simulation, with repeat simulation testing one month after their teaching intervention. The time from cardiac arrest to start of perimortem Cesarean delivery (PMCD) was measured, and the technical and nontechnical skills scores between the two teaching groups were compared. The median [interquartile range] time to PMCD decreased after teaching, from 4.5 min [3.4 to 5.1 min] to 3.5 min [2.5 to 4.0 min] (P = 0.03), although the change within each group was not statistically significant (Didactic group 4.9 to 3.8 min, P = 0.2; Electronic group 3.9 to 2.5 min, P = 0.07; Didactic group vs Electronic group, P = 1.0). Even after teaching, only 65% of participants started PMCD within four minutes. Technical and nontechnical skills scores improved after teaching in both groups, and there were no differences between the groups. There are gaps in the knowledge and implementation of resuscitation protocols and the recommended modifications for pregnancy among residents. Teaching can improve performance during management of maternal cardiac arrest. Electronic learning and didactic teaching offer similar benefits.

  11. Status of electronic waste recycling techniques: a review.

    PubMed

    Abdelbasir, Sabah M; Hassan, Saad S M; Kamel, Ayman H; El-Nasr, Rania Seif

    2018-05-08

    The increasing use of electrical and electronic equipment leads to a huge generation of electronic waste (e-waste). It is the fastest growing waste stream in the world. Almost all electrical and electronic equipment contain printed circuit boards as an essential part. Improper handling of these electronic wastes could bring serious risk to human health and the environment. On the other hand, proper handling of this waste requires a sound management strategy for awareness, collection, recycling, and reuse. Nowadays, the effective recycling of this type of waste has been considered as a main challenge for any society. Printed circuit boards (PCBs), which are the base of many electronic industries, are rich in valuable heavy metals and toxic halogenated organic substances. In this review, the composition of different PCBs and their harmful effects are discussed. Various techniques in common use for recycling the most important metals from the metallic fractions of e-waste are illustrated. The recovery of metals from e-waste material after physical separation through pyrometallurgical, hydrometallurgical, or biohydrometallurgical routes is also discussed, along with alternative uses of non-metallic fraction. The data are explained and compared with the current e-waste management efforts done in Egypt. Future perspectives and challenges facing Egypt for proper e-waste recycling are also discussed.

  12. Creating a Living Portfolio: Documenting Student Growth with Electronic Portfolios.

    ERIC Educational Resources Information Center

    Siegle, Del

    2002-01-01

    This article explains how teachers can use electronic portfolios of students' work to document learner progress. It considers different file formats for storing student work, describes steps to creating an electronic portfolio, and discusses an art and literature electronic magazine created by one school featuring work from student portfolios. (CR)

  13. Measuring electron temperature in the extended corona

    NASA Technical Reports Server (NTRS)

    Hassler, Donald M.; Gardner, L. D.; Kohl, John L.

    1992-01-01

    A technique for measuring electron temperature in the extended corona from the line profile of the electron scattered component of coronal H I Ly alpha produced by Thomson scattering of chromospheric Ly alpha emission is discussed. Because of the high thermal velocity of electrons at coronal temperatures (approximately 6800 km/s at T(sub e) = 1,500,000 K) the effect of nonthermal velocities and solar wind flows on the electron velocity distribution are negligible. However, the low electron mass which is responsible for the high thermal velocity also results in a very wide profile (approximately equal to 50 A). This wide profile, together with an intensity that is three orders of magnitude weaker than the resonantly scattered component of Ly alpha makes the direct measurement of T(sub e) a challenging observational problem. An evaluation of this technique based on simulated measurements is presented and the subsequent instrumental requirements necessary to make a meaningful determination of the electron temperature are discussed. Estimates of uncertainties in the measured electron temperature are related to critical instrument parameters such as grating stray light suppression.

  14. Patient engagement in the inpatient setting: a systematic review

    PubMed Central

    Prey, Jennifer E; Woollen, Janet; Wilcox, Lauren; Sackeim, Alexander D; Hripcsak, George; Bakken, Suzanne; Restaino, Susan; Feiner, Steven; Vawdrey, David K

    2014-01-01

    Objective To systematically review existing literature regarding patient engagement technologies used in the inpatient setting. Methods PubMed, Association for Computing Machinery (ACM) Digital Library, Institute of Electrical and Electronics Engineers (IEEE) Xplore, and Cochrane databases were searched for studies that discussed patient engagement (‘self-efficacy’, ‘patient empowerment’, ‘patient activation’, or ‘patient engagement’), (2) involved health information technology (‘technology’, ‘games’, ‘electronic health record’, ‘electronic medical record’, or ‘personal health record’), and (3) took place in the inpatient setting (‘inpatient’ or ‘hospital’). Only English language studies were reviewed. Results 17 articles were identified describing the topic of inpatient patient engagement. A few articles identified design requirements for inpatient engagement technology. The remainder described interventions, which we grouped into five categories: entertainment, generic health information delivery, patient-specific information delivery, advanced communication tools, and personalized decision support. Conclusions Examination of the current literature shows there are considerable gaps in knowledge regarding patient engagement in the hospital setting and inconsistent use of terminology regarding patient engagement overall. Research on inpatient engagement technologies has been limited, especially concerning the impact on health outcomes and cost-effectiveness. PMID:24272163

  15. Pentafluorobenzyl bromide-A versatile derivatization agent in chromatography and mass spectrometry: I. Analysis of inorganic anions and organophosphates.

    PubMed

    Tsikas, Dimitrios

    2017-02-01

    Pentafluorobenzyl bromide (PFB-Br) is a versatile derivatization agent. It is widely used in chromatography and mass spectrometry since several decades. The bromide atom is largely the single leaving group of PFB-Br. It is substituted by wide a spectrum of nucleophiles in aqueous and non-aqueous systems to form electrically neutral, in most organic solvents soluble, generally thermally stable, volatile, strongly electron-capturing and ultraviolet light-absorbing derivatives. Because of these greatly favoured physicochemical properties, PFB-Br emerged an ideal derivatization agent for highly sensitive analysis of endogenous and exogenous substances including various inorganic and organic anions by electron capture detection or after electron-capture negative-ion chemical ionization in GC-MS. The present article attempts an appraisal of the utility of PFB-Br in analytical chemistry. It reviews and discusses papers dealing with the use of PFB-Br as the derivatization reagent in the qualitative and quantitative analysis of endogenous and exogenous inorganic anions in various biological samples, notably plasma, urine and saliva. These analytes include nitrite, nitrate, cyanide and dialkyl organophosphates. Special emphasis is given to mass spectrometry-based approaches and stable-isotope dilution techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Dose specification for radiation therapy: dose to water or dose to medium?

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, Jinsheng

    2011-05-01

    The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis.

  17. D-region positive and negative ion concentration and mobilities during the February 1979 eclipse

    NASA Astrophysics Data System (ADS)

    Conley, T. D.; Narcisi, R. S.; Hegblom, E. R.

    1983-07-01

    Positive and negative ion concentrations and mobilities have been obtained from an analysis of Gerdien condenser measurements on rocket flights, A10.802-1 and A10.802-2, during and after eclipse totality. The aerodynamic instrument calibration and the data analysis techniques are discussed. The measured concentrations on both flights were about 10,000/cu cm in the altitudes range, 45-80 km. These high concentrations at very low altitudes suggest that a relativistic electron precipitation event was occurring during the measurements. The ion concentration measurements along with electron density measurements made by other groups during the eclipse were used to calculate the negative ion/ electron ratio, and the lumped parameter detachment rate. These results are compared with prior measurements during eclipse and solar proton events and code results. The analysis shows that the present negative ion model is incomplete. The reduced mobilities were also determined. The mobility distributions show that the heavy ions of both the positive and negative species dominate from 45 to 70 km. The data reveal more massive ions at higher altitudes than at low altitudes (1000 vs 300 a.m.u.) as well as possible evidence for multiply charged ions below about 60 km.

  18. Wave-Particle Interactions in the Earth's Radiation Belts: Recent Advances and Unprecedented Future Opportunities

    NASA Astrophysics Data System (ADS)

    Li, W.

    2017-12-01

    In the collisionless heliospheric plasmas, wave-particle interaction is a fundamental physical process in transferring energy and momentum between particles with different species and energies. This presentation focuses on one of the important wave-particle interaction processes: interaction between whistler-mode waves and electrons. Whistler-mode waves have frequencies between proton and electron cyclotron frequency and are ubiquitously present in the heliospheric plasmas including solar wind and planetary magnetospheres. I use Earth's Van Allen radiation belt as "local space laboratory" to discuss the role of whistler-mode waves in energetic electron dynamics using multi-satellite observations, theory and modeling. I further discuss solar wind drivers leading to energetic electron dynamics in the Earth's radiation belts, which is critical in predicting space weather that has broad impacts on our technological systems and society. At last, I discuss the unprecedented future opportunities of exploring space science using multi-satellite observations and state-of-the-art theory and modeling.

  19. Smart Technology in Lung Disease Clinical Trials.

    PubMed

    Geller, Nancy L; Kim, Dong-Yun; Tian, Xin

    2016-01-01

    This article describes the use of smart technology by investigators and patients to facilitate lung disease clinical trials and make them less costly and more efficient. By "smart technology" we include various electronic media, such as computer databases, the Internet, and mobile devices. We first describe the use of electronic health records for identifying potential subjects and then discuss electronic informed consent. We give several examples of using the Internet and mobile technology in clinical trials. Interventions have been delivered via the World Wide Web or via mobile devices, and both have been used to collect outcome data. We discuss examples of new electronic devices that recently have been introduced to collect health data. While use of smart technology in clinical trials is an exciting development, comparison with similar interventions applied in a conventional manner is still in its infancy. We discuss advantages and disadvantages of using this omnipresent, powerful tool in clinical trials, as well as directions for future research. Published by Elsevier Inc.

  20. Microbiome involved in microbial electrochemical systems (MESs): A review.

    PubMed

    Saratale, Rijuta Ganesh; Saratale, Ganesh Dattatraya; Pugazhendhi, Arivalagan; Zhen, Guangyin; Kumar, Gopalakrishnan; Kadier, Abudukeremu; Sivagurunathan, Periyasamy

    2017-06-01

    Microbial electrochemical systems (MESs) are an attracting technology for the disposal of wastewater treatment and simultaneous energy production. In MESs, at the anode microorganisms through the catalytic activity generates electrons that can be converted into electricity or other valuable chemical compounds. Microorganisms those having ability to donate and accept electrons to and from anode and cathode electrodes, respectively are recognized as 'exoelectrogens'. In the MESs, it renders an important function for its performance. In the present mini-review, we have discussed the role of microbiome including pure culture, enriched culture and mixed culture in different BESs application. The effects of operational and biological factors on microbiome development have been discussed. Further discussion about the molecular techniques for the evaluation of microbial community analysis is addressed. In addition different electrochemical techniques for extracellular electron transfer (EET) mechanism of electroactive biofilms have been discussed. This review highlights the importance of microbiome in the development of MESs, effective operational factors for exo-electrogens activities as well their key challenges and future technological aspects are also briefly discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

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