WorldWideScience

Sample records for theoretical study final

  1. Final Report May 1, 2012 to May 31, 2015: "Theoretical Studies in Elementary Particle Physics"

    Energy Technology Data Exchange (ETDEWEB)

    Collins, John C. [Pennsylvania State Univ., State College, PA (United States); Roiban, Radu [Pennsylvania State Univ., State College, PA (United States)

    2015-08-19

    This final report summarizes work at Penn State University from May 1, 2012 to May 31, 2015. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

  2. Theoretical studies of the heating of toroidal plasmas with radio frequency electromagnetic radiation. Final report

    International Nuclear Information System (INIS)

    Glasser, A.H.; Swanson, D.G.; Wersinger, J.M.

    1982-01-01

    The continuation of a program of theoretical studies of the heating of toroidal plasmas with radio frequency (RF) electromagnetic radiation is proposed. Funding for this project first began on September 3, 1981, and will expire on April 2, 1982. A summary of the principal accomplishments of the first five months of the project is presented. These include the acquisition of computer terminals and modems, the implementation of existing codes on the MFECC C Cray Computer, the extension of the LHTOR lower hybrid toroidal ray tracing code to the full electromagnetic dispersion relation, the implementation of graphic output from the code, the beginning of extensive parameter studies, the beginning of an analytical treatment of the mode conversion layer associated with singular harmonic absorption, and the introduction of a graduate student into the program

  3. Theoretical nuclear reaction and structure studies using hyperons and photons. Final report

    International Nuclear Information System (INIS)

    Cotanch, S.R.

    1998-01-01

    This report details research progress and results obtained during the ten period from June 1, 1988 through May 31, 1998. In compliance with grant requirements the Principal Investigator, Professor Stephen R. Cotanch, has conducted a research program addressing theoretical investigations of reactions involving hyperons and photons. The Principal Investigator has devoted to this program 50% of his time during the academic year and 100% of this time in the summer. Highlights of significant research results are briefly summarized in this report which respectively correspond to the three sub-programs of this project

  4. Theoretical studies in nuclear physics. Three year progress report and final report

    International Nuclear Information System (INIS)

    Landau, R.H.; Madsen, V.A.

    1996-01-01

    In 1995 the DOE grant in Nuclear theory with Professors Rubin H. Landau and Victor A. Madsen as co-principal investigators ended. Their research was carried out in collaboration with graduate students in Corvallis, and with scientists at LLNL-Livermore, Los Alamos, TRIUMF, KFA-Julich, Hamburg University, Melbourne University, The Thinking Machine Corporation and IBM Research. Activities in nuclear and particle physics at Oregon State University (OSU) were diverse and active. Madsen's work concentrated on the relation of reactions to the nuclear structure, and Landau's work concentrated on intermediate energy physics, few-body problems, and computational physics. The Landau group had a weekly meeting of students and visitors. There was a weekly nuclear seminar with experimental and theoretical colleagues, and a weekly departmental colloquium. The DOE support had permitted the group to run Unix workstations networked to other computers in the Physics Department and the University. Since 1990 OSU has been using IBM RISC System 6000/model 530 with console and four X-stations. The equipment was purchased and is maintained with yearly DOE funding of the group

  5. Theoretical studies in nuclear structure. Final progress report, June 1, 1991--July 31, 1996

    International Nuclear Information System (INIS)

    Marshalek, E.R.

    1997-01-01

    The general purview of the project is the theory of collective motion in atomic nuclei. The chief aim is to elucidate the phenomena of (1) anharmonic multiphonon excitations, and (2) collective tilted rotation, both of which are topics of considerable current interest. In the primary stage of an investigation it is often necessary to develop appropriate mathematical tools, as was the case here. In the next stage, the formalism must be tested on simple soluble models. The work described here is mainly concerned with these two stages. The final stage of realistic applications will require more time, manpower and, of course, the necessary funding. Some planning for this last stage has been carried out and anticipated problems axe briefly discussed. As it turns out, both of the above topics can be approached within the unified framework of a theorem that I developed, called the Cranking Bifurcation Theorem (CBT) to be described below. The CBT can be regarded as an outgrowth of the boson expansion method, which provides a general, and, in principal, exact formalism for treating collective excitations. We begin with a brief discussion of the CBT and then continue on to the applications

  6. Theoretical studies of magnetic systems. Final report, August 1, 1994--November 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Gor`kov, L.P.; Novotny, M.A.; Schrieffer, J.R.

    1997-12-31

    During the grant period the authors have studied five areas of research: (1) low dimensional ferrimagnets; (2) lattice effects in the mixed valence problem; (3) spin compensation in the one dimensional Kondo lattice; (4) the interaction of quasi particles in short coherence length superconductors; and (5) novel effects in angle resolved photoemission spectra from nearly antiferromagnetic materials. Progress in each area is summarized.

  7. Theoretical and experimental studies of fixed-bed coal gasification reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, B.; Bhattacharya, A.; Salam, L.; Dudukovic, M.P.

    1983-09-01

    A laboratory fixed-bed gasification reactor was designed and built with the objective of collecting operational data for model validation and parameter estimation. The reactor consists of a 4 inch stainless steel tube filled with coal or char. Air and steam is fed at one end of the reactor and the dynamic progress of gasification in the coal or char bed is observed through thermocouples mounted at various radial and axial locations. Product gas compositions are also monitored as a function of time. Results of gasification runs using Wyoming coal are included in this report. In parallel with the experimental study, a two-dimensional model of moving bed gasifiers was developed, coded into a computer program and tested. This model was used to study the laboratory gasifier by setting the coal feed rate equal to zero. The model is based on prior work on steady state and dynamic modeling done at Washington University and published elsewhere in the literature. Comparisons are made between model predictions and experimental results. These are also included in this report. 23 references, 18 figures, 6 tables.

  8. Input–Output Matrix study: A theoretical frame to study the impact of Brazilian IPI reduction in final demand

    Directory of Open Access Journals (Sweden)

    Rodrigo Emmanuel Santana Borges

    2014-05-01

    Full Text Available The economic crisis of 2008–2009 will be known as the day when the creator knelt before its creation (Syll, 2010. Amid such economic mess created by economists (and so-called engineers themselves, there seems to be a single economic perspective: every man for himself and save yourself if you can. In the midst of this major disruption in the global economy, the Brazilian government decided, in a set of economic measures, to promote a partial and time-limited VAT reduction as its main countercyclical policy. This paper proposes to measure which were the direct and indirect effects of lowering the taxes for a limited time on production, employment generation and income. Additionally, it intends to check whether the reduction on IPI level, a tax that is one of the VATs in Brazil, was indeed the most efficient choice among the other value added taxes in Brazil. In order to accomplish such objectives, a simple final demand model for the GDP is adopted, and the latest national accounts input–output data is taken as a basis to infer the multipliers for the variables chosen and to estimate hypothetical impacts of reduction in other taxes instead of IPI reduction in the specific sector. Currently, the consensus is that the countercyclical economic policy adopted in Brazil had a positive result and fulfilled the expected goals.

  9. Research in theoretical physics. Final report

    International Nuclear Information System (INIS)

    Frampton, P.H.; Choi, S.I.; Ng, Y.J.; Manire, G.P.; vanDam, H.

    1986-01-01

    Results are reported briefly in these theoretical areas: higher-dimensional anomalies, spontaneous compactification, supersymmetric confining models of the weak interactions, spacetime thermodynamics and the inflationary universe, spin-dependent forces in the quarkonium systems, scalar-quark bound states, construction of a self-interacting massless spin 3 theory, relativistic corrections in quarkonium, scalar quarkonium production supergravity and unified theories, supersymmetric unified theories and hierarchy problems, and family unification in higher dimensions

  10. A theoretical and numerical study of the flow of granular materials down an inclined plane. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K.R.

    1995-12-31

    The mechanics of the flowing granular materials such as coal, agricultural products, at deal of attention as it has fertilizers, dry chemicals, metal ores, etc. have received a great deal of attention as it has relevance to several important technological problems. Despite wide interest and more than five decades of experimental and theoretical investigations, most aspects of the behavior of flowing granular materials are still not well understood. So Experiments have to be devised which quantify and describe the non-linear behavior of the modular materials, and theories developed which can explain the experimentally observed facts. As many models have been suggested for describing the behavior of granular materials, from both continuum and kinetic theory viewpoints, we proposed to investigate the validity and usefulness of representative models from both the continuum and kinetic theory points of view, by determining the prediction of such a theory, in a representative flow, with respect to existence, non-existence, multiplicity and stability of solutions. The continuum model to be investigated is an outgrowth of a model due to Goodman and Cowin (1971, 1972) and the kinetic theory models being those due to Jenkins and Richman (1985) and Boyle and Massoudi (1989). In this report we present detailed results regarding the same. Interestingly, we find that the predictions of all the theories, in certain parameter space associated with these models, are qualitatively similar. This ofcourse depends on the values assumed for various material parameters in the models, which as yet are unknown, as reliable experiments have not been carried out as yet for their determination.

  11. Theoretical studies of multistep processes, isospin effects in nuclear scattering, and meson and baryon interactions in nuclear physics. Final technical report, 1 September 1979-30 April 1986

    International Nuclear Information System (INIS)

    Madsen, V.A.; Landau, R.H.

    1986-01-01

    Final technical report on a contract supporting theoretical studies in nuclear physics at Oregon State University is presented. The research was led by Professors Landau and Madsen and carried out in collaboration with graduate students in Corvallis and scientists at LLNL-Livermore, KFA-Julich, Purdue University-West Lafayette, University of Oregon-Eugene, Florida State University-Talahasie, and TRIUMF-Vancouver. The studies included meson exchange current effects, quark effects,and relativistic/Dirac effects deduced from spin observables in p- 3 He scattering, coupled bound and continuum eigenstates in momentum space for kaons and antiprotons, and charge symmetry violation in π scattering from trinucleons. Additional studies included microscopic optical potential calculations, multiple step processes, and differences in neutron and proton multipole matrix elements in low lying collective states and in giant resonances. 45 refs

  12. An experimental and theoretical study to relate uncommon rock/fluid properties to oil recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.

    1995-07-01

    Waterflooding is the most commonly used secondary oil recovery technique. One of the requirements for understanding waterflood performance is a good knowledge of the basic properties of the reservoir rocks. This study is aimed at correlating rock-pore characteristics to oil recovery from various reservoir rock types and incorporating these properties into empirical models for Predicting oil recovery. For that reason, this report deals with the analyses and interpretation of experimental data collected from core floods and correlated against measurements of absolute permeability, porosity. wettability index, mercury porosimetry properties and irreducible water saturation. The results of the radial-core the radial-core and linear-core flow investigations and the other associated experimental analyses are presented and incorporated into empirical models to improve the predictions of oil recovery resulting from waterflooding, for sandstone and limestone reservoirs. For the radial-core case, the standardized regression model selected, based on a subset of the variables, predicted oil recovery by waterflooding with a standard deviation of 7%. For the linear-core case, separate models are developed using common, uncommon and combination of both types of rock properties. It was observed that residual oil saturation and oil recovery are better predicted with the inclusion of both common and uncommon rock/fluid properties into the predictive models.

  13. Theoretical Advanced Study Institute: 2014

    Energy Technology Data Exchange (ETDEWEB)

    DeGrand, Thomas [Univ. of Colorado, Boulder, CO (United States)

    2016-08-17

    The Theoretical Advanced Study Institute (TASI) was held at the University of Colorado, Boulder, during June 2-27, 2014. The topic was "Journeys through the Precision Frontier: Amplitudes for Colliders." The organizers were Professors Lance Dixon (SLAC) and Frank Petriello (Northwestern and Argonne). There were fifty-one students. Nineteen lecturers gave sixty seventy-five minute lectures. A Proceedings was published. This TASI was unique for its large emphasis on methods for calculating amplitudes. This was embedded in a program describing recent theoretical and phenomenological developments in particle physics. Topics included introductions to the Standard Model, to QCD (both in a collider context and on the lattice), effective field theories, Higgs physics, neutrino interactions, an introduction to experimental techniques, and cosmology.

  14. Theoretical studies of combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, J.M. [Emory Univ., Atlanta, GA (United States)

    1993-12-01

    The basic objectives of this research program are to develop and apply theoretical techniques to fundamental dynamical processes of importance in gas-phase combustion. There are two major areas currently supported by this grant. One is reactive scattering of diatom-diatom systems, and the other is the dynamics of complex formation and decay based on L{sup 2} methods. In all of these studies, the authors focus on systems that are of interest experimentally, and for which potential energy surfaces based, at least in part, on ab initio calculations are available.

  15. Research in theoretical nuclear and neutrino physics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sarcevic, Ina [Univ. of Arizona, Tucson, AZ (United States). Dept. of Physics

    2014-06-14

    The main focus of the research supported by the nuclear theory grant DE-FG02-04ER41319 was on studying parton dynamics in high-energy heavy ion collisions, perturbative approach to charm production and its contribution to atmospheric neutrinos, application of AdS/CFT approach to QCD, neutrino signals of dark mattter annihilation in the Sun and on novel processes that take place in dense stellar medium and their role in stellar collapse, in particular the effect of new neutrino interactions on neutrino flavor conversion in Supernovae. We present final technical report on projects completed under the grant.

  16. THEORETICAL ASPECTS OF FILMMUSIC STUDY

    Directory of Open Access Journals (Sweden)

    Egorova Tatiana K.

    2014-04-01

    Full Text Available In this article, author analyzes the theoretical aspects of the film music study taking into account with modern realities in the development of world film-process and attempts to its scientific understanding. Need for innovation in this area is long overdue, because the existing on this topic nonfiction no longer meets the new aesthetic and art-practical achievements and innovations in the film music development at the XXI century. Related to the phenomenon of music in screen arts a number of new terms and concepts require a certain adjustment as well. Their range of action is not yet fully defined. Author of the article offered her version of their content-semantic interpretation (largely experimental designed to promote new research methods for the film music study.

  17. Final Report. Research in Theoretical High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Greensite, Jeffrey P. [San Francisco State Univ., CA (United States); Golterman, Maarten F.L. [San Francisco State Univ., CA (United States)

    2015-04-30

    Grant-supported research in theoretical high-energy physics, conducted in the period 1992-2015 is briefly described, and a full listing of published articles result from those research activities is supplied.

  18. Studies In Theoretical High Energy Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Keung, Wai Yee [Univ. of Illinois, Chicago, IL (United States)

    2017-07-01

    This is a final technical report for grant no. DE-SC0007948 describing research activities in theoretical high energy physics at University of Illinois at Chicago for the whole grant period from July 1, 2012 to March 31, 2017.

  19. CO oxidation on gold nanoparticles: Theoretical studies

    DEFF Research Database (Denmark)

    Remediakis, Ioannis; Lopez, Nuria; Nørskov, Jens Kehlet

    2005-01-01

    We present a summary of our theoretical results regarding CO oxidation on both oxide-supported and isolated gold nanoparticles. Using Density Functional Theory we have studied the adsorption of molecules and the oxidation reaction of CO on gold clusters. Low-coordinated sites on the gold...... nanoparticles can adsorb small inorganic molecules such as O2 and CO, and the presence of these sites is the key factor for the catalytic properties of supported gold nanoclusters. Other contributions, induced by the presence of the support, can provide parallel channels for the reaction and modulate the final...

  20. Theoretical Studies of Elementary Hydrocarbon Species and Their Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Wesley D. [Univ. of Georgia, Athens, GA (United States). Dept. of Chemistry. Center for Computational Quantum Chemistry; Schaefer, III, Henry F. [Univ. of Georgia, Athens, GA (United States). Dept. of Chemistry. Center for Computational Quantum Chemistry

    2015-11-14

    This is the final report of the theoretical studies of elementary hydrocarbon species and their reactions. Part A has a bibliography of publications supported by DOE from 2010 to 2016 and Part B goes into recent research highlights.

  1. Theoretical investigations of grout seal longevity - Final report

    International Nuclear Information System (INIS)

    Alcorn, S.; Coons, W.; Christian-Frear, T.; Wallace, M.

    1992-04-01

    Theoretical investigations into the longevity of repository seals have dealt primarily with the development of a methodology to evaluate interactions between portland cement-based grout and groundwater. Evaluation of chemical thermodynamic equilibria between grout and groundwater, and among grout, groundwater, and granitic host rock phases using the geochemical codes EQ3NR/EQ6 suggests that a fracture filled with grout and saturated with groundwater will tend to fill and 'tighten' with time. Results of these investigations suggest that cement grout seals will maintain an acceptable level of performance for tens of thousands to millions of years, provided the repository is sited where groundwater chemistry is compatible with the seals and hydrologic gradients are low. The results of the grout: groundwater: rock calculations suggest that buffering of the fracture seals chemical systems by the granite rock may be important in determining the long-term fate of grout seals and the resulting phase assemblage in the fracture. The similarity of the modelled reaction products to those observed in naturally filled fractures suggests that with time equilibrium will be approached and grouted fractures subject to low hydrologic gradients will continue to seal. If grout injected into fractures materially reduces groundwater flux, the approach to chemical equilibrium will likely be accelerated. In light of this, even very thin or imperfectly grouted fractures would tighten in suitable hydrogeologic environments. (29 refs.) (au)

  2. Theoretical Studies in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Collins, John C.; Roiban, Radu S

    2013-04-01

    This final report summarizes work at Penn State University from June 1, 1990 to April 30, 2012. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

  3. Theoretical studies in nuclear physics

    International Nuclear Information System (INIS)

    Landau, R.H.; Madsen, V.A.

    1991-01-01

    This report discusses research in nuclear theory in the following areas: Isospin effects and charge exchange; inelastic and charge exchange scattering; momentum space proton scattering; pion scattering from nuclei; and antiproton studies. 14 refs

  4. Theoretical studies of unconventional superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Groensleth, Martin Sigurd

    2008-07-01

    This thesis presents four research papers. In the first three papers we have derived analytical results for the transport properties in unconventional superconductors and ferromagnetic systems with multiple broken symmetries. In Paper I and parts of Paper II we have studied tunneling transport between two non-unitary ferromagnetic spin-triplet superconductors, and found a novel interplay between ferromagnetism and superconductivity manifested in the Josephson effect as a spin- and charge-current in the absence of an applied voltage across the junction. The critical amplitudes of these currents can be adjusted by the relative magnetization direction on each side of the junction. Furthermore, in Paper II, we have found a way of controlling a spin-current between two ferromagnets with spin-orbit coupling. Paper III considers a junction consisting of a ferromagnet and a non-unitary ferromagnetic superconductor, and we show that the conductance spectra contains detailed information about the superconducting gaps and pairing symmetry of the Cooper-pairs. In the last paper we present a Monte Carlo study of an effective Hamiltonian describing orbital currents in the CuO2 layers of high-temperature superconductive cuprates. The model features two intrinsically anisotropic Ising models, coupled through an anisotropic next-nearest neighbor interaction, and an Ashkin-Teller nearest neighbor fourth order coupling. We have studied the specific heat anomaly, as well as the anomaly in the staggered magnetization associated with the orbital currents and its susceptibility. We have found that in a limited parameter regime, the specific heat anomaly is substantially suppressed, while the susceptibility has a non-analytical peak across the order-disorder transition. The model is therefore a candidate for describing the breakup of hidden order when crossing the pseudo-gap line on the under-doped side in the phase diagram of high-temperature superconductors. (Author) 64 refs., figs

  5. Theoretical study of free electron laser physics

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Gwon; Cho, Sung Oh; Jeong, Young Uk; Kim, Sun Kook; Lee, Byung Cheol; Cha, Byung Heon; Lee, Jong Min [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-04-01

    A theoretical study of free electron laser physics is presented in this report. In particular, an analysis is given of the free electron laser with a linearly polarized magnetic wiggler. We describe the basic electron dynamics and gain mechanism in a free electron laser by solving the one-body classical Lorentz force equations in the presence of a periodic magnetic field and a plane electromagnetic wave. Phase space paths for electrons analogously related to those of a simple pendulum are used to describe the laser gain and saturation, and the evolution of the electron beam energy and position distributions. We present an analysis of the single-mode problem and a self-consistent nonlinear treatment of the finite transverse dimensional effects associated with the free electron laser in a steady state. Results computed by applying an external D.C. electric field to the system are discussed for investigating efficiency enhancement of the free electron lasers. Finally optical guiding effect in small signal regime is described to investigate the possibility of amplifying radiation fields in very long wigglers for large gain and high extraction efficiency. 14 refs., 45 figs. (Author)

  6. DOE-HEP Final Report for 2013-2016: Studies of plasma wakefields for high repetition-rate plasma collider, and Theoretical study of laser-plasma proton and ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Katsouleas, Thomas C. [Duke Univ., Durham, NC (United States). Dept. of Electrical and Computer Engineering; Sahai, Aakash A. [Imperial College, London (United Kingdom). Dept. of Physics

    2016-08-08

    There were two goals for this funded project: 1. Studies of plasma wakefields for high repetition-rate plasma collider, and 2. Theoretical study of laser-plasma proton and ion acceleration. For goal 1, an analytical model was developed to determine the ion-motion resulting from the interaction of non-linear “blow-out” wakefields excited by beam-plasma and laser-plasma interactions. This is key to understanding the state of the plasma at timescales of 1 picosecond to a few 10s of picoseconds behind the driver-energy pulse. More information can be found in the document. For goal 2, we analytically and computationally analyzed the longitudinal instabilities of the laser-plasma interactions at the critical layer. Specifically, the process of “Doppler-shifted Ponderomotive bunching” is significant to eliminate the very high-energy spread and understand the importance of chirping the laser pulse frequency. We intend to publish the results of the mixing process in 2-D. We intend to publish Chirp-induced transparency. More information can be found in the document.

  7. Theoretical studies of chemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, G.C. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This collaborative program with the Theoretical Chemistry Group at Argonne involves theoretical studies of gas phase chemical reactions and related energy transfer and photodissociation processes. Many of the reactions studied are of direct relevance to combustion; others are selected they provide important examples of special dynamical processes, or are of relevance to experimental measurements. Both classical trajectory and quantum reactive scattering methods are used for these studies, and the types of information determined range from thermal rate constants to state to state differential cross sections.

  8. Surfactants, interfaces and pores : a theoretical study

    NARCIS (Netherlands)

    Huinink, H.

    1998-01-01

    The aim of this study was to investigate the behavior of surfactants in porous media by theoretical means. The influence of curvature of a surface on the adsorption has been studied with a mean field lattice (MFL) model, as developed by Scheutjens and Fleer. An analytical theory has been

  9. Experimental and Theoretical Progress of Linear Collider Final Focus Design and ATF2 Facility

    CERN Document Server

    Seryi, Andrei; Zimmermann, Frank; Kubo, Kiyoshi; Kuroda, Shigeru; Okugi, Toshiyuki; Tauchi, Toshiaki; Terunuma, Nobuhiro; Urakawa, Junji; White, Glen; Woodley, Mark; Angal-Kalinin, Deepa

    2014-01-01

    In this brief overview we will reflect on the process of the design of the linear collider (LC) final focus (FF) optics, and will also describe the theoretical and experimental efforts on design and practical realisation of a prototype of the LC FF optics implemented in the ATF2 facility at KEK, Japan, presently being commissioned and operated.

  10. Theoretical and simulation studies of seeding methods

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, Claudio [Univ. of California, Los Angeles, CA (United States)

    2017-12-11

    We report the theoretical and experimental studies done with the support of DOE-Grant DE-SC0009983 to increase an X-ray FEL peak power from the present level of 20 to 40 GW to one or more TW by seeding, undulator tapering and using the new concept of the Double Bunch FEL.

  11. THEORETICAL STUDY ON ELECTRONIC STRUCTURES AND ...

    African Journals Online (AJOL)

    THEORETICAL STUDY ON ELECTRONIC STRUCTURES AND SPECTROSCOPY OF TRIARYLBORANE SUBSTITUTED BY THIOPHENE. ... Also, the 13C chemical shifts of the carbon atoms on the phenyl rings in these compounds are upfield relative to those of the same carbon atoms in the parent compound.

  12. Information Theoretic Studies and Assessment of Space Object Identification

    Science.gov (United States)

    2014-03-24

    AFRL-OSR-VA-TR-2014-0119 INFORMATION THEORETIC STUDIES AND ASSESMENTS OF SPACE-OBJECT IDENTIFICATION Sudhakar Prasad UNIVERSITY OF NEW MEXICO Final...5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME...S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND

  13. Theoretical studies on energetic materials bearing pentaflurosulphyl ...

    Indian Academy of Sciences (India)

    Theoretical studies on the compounds with SF5 groups. 1167. Table 2. Calculated total energies (E0), zero-point energies (ZPE), densities and heats of formation (HOFs) for the title energetic materials. E0 and ZPE are in a.u., HOFs are in kJ/mol, densities are in g/cm3. Compound. E0. ZPE. Hf, gas. Hf, sub. Hf, solid. Density.

  14. Theoretical pluralism in psychoanalytic case studies

    Directory of Open Access Journals (Sweden)

    Jochem eWillemsen

    2015-09-01

    Full Text Available The aim of this study is to provide an overview of the scientific activity of different psychoanalytic schools of thought in terms of the content and production of case studies published on ISI Web of Knowledge. Between March 2013 and November 2013, we contacted all case study authors included in the online archive of psychoanalytic and psychodynamic case studies (www.singlecasearchive.com to inquire about their psychoanalytic orientation during their work with the patient. The response rate for this study was 45%. It appears that the two oldest psychoanalytic schools, Object-relations psychoanalysis and Ego psychology or ‘Classical psychoanalysis’ dominate the literature of published case studies. However, most authors stated that they feel attached to two or more psychoanalytic schools of thought. This confirms that the theoretical pluralism in psychoanalysis stretches to the field of single case studies. The single case studies of each psychoanalytic school are described separately in terms of methodology, patient, therapist, or treatment features. We conclude that published case studies features are fairly similar across different psychoanalytic schools. The results of this study are not representative of all psychoanalytic schools, as some do not publish their work in ISI ranked journals.

  15. Theoretical pluralism in psychoanalytic case studies

    Science.gov (United States)

    Willemsen, Jochem; Cornelis, Shana; Geerardyn, Filip M.; Desmet, Mattias; Meganck, Reitske; Inslegers, Ruth; Cauwe, Joachim M. B. D.

    2015-01-01

    The aim of this study is to provide an overview of the scientific activity of different psychoanalytic schools of thought in terms of the content and production of case studies published on ISI Web of Knowledge. Between March 2013 and November 2013, we contacted all case study authors included in the online archive of psychoanalytic and psychodynamic case studies (www.singlecasearchive.com) to inquire about their psychoanalytic orientation during their work with the patient. The response rate for this study was 45%. It appears that the two oldest psychoanalytic schools, Object-relations psychoanalysis and Ego psychology or “Classical psychoanalysis” dominate the literature of published case studies. However, most authors stated that they feel attached to two or more psychoanalytic schools of thought. This confirms that the theoretical pluralism in psychoanalysis stretches to the field of single case studies. The single case studies of each psychoanalytic school are described separately in terms of methodology, patient, therapist, or treatment features. We conclude that published case studies features are fairly similar across different psychoanalytic schools. The results of this study are not representative of all psychoanalytic schools, as some do not publish their work in ISI ranked journals. PMID:26483725

  16. Theoretical study of fractal growth and stability on surface

    DEFF Research Database (Denmark)

    Dick, Veronika V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    We perform a theoretical study of the fractal growing process on surface by using the deposition, diffusion, aggregation method. We present a detailed analysis of the post-growth processes occurring in a nanofractal on surface. For this study we developed a method which describes the internal...... dynamics of particles in a fractal and accounts for their diffusion and detachment. We demonstrate that these kinetic processes are responsible for the formation of the final shape of the islands on surface after the post-growth relaxation....

  17. Theoretical studies on aerosol agglomeration processes

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, K.E.J. [VTT Energy, Espoo (Finland). Energy Use

    1997-12-31

    In this thesis, theoretical modeling of certain aerosol systems has been presented. At first, the aerosol general dynamic equation is introduced, along with a discretization routine for its numerical solution. Of the various possible phenomena affecting aerosol behaviour, this work is mostly focused on aerosol agglomeration. The fundamentals of aerosol agglomeration theory are thus briefly reviewed. The two practical applications of agglomeration studied in this thesis are flue gas cleaning using an electrical agglomerator and nanomaterial synthesis with a free jet reactor. In an electrical agglomerator the aerosol particles are charged and brought into an alternating electric field. The aim is to remove submicron particles from flue gases by collisions with larger particles before conventional gas cleaning devices that have a clear penetration window in the problematic 0.1-1{mu}m size range. A mathematical model was constructed to find out the effects of the different system parameters on the agglomerator`s performance. A crucial part of this task was finding out the collision efficiencies of particles of varying size and charge. The original idea was to use unipolar charging of the particles, and a laboratory scale apparatus was constructed for this purpose. Both theory and experiments clearly show that significant removal of submicron particles can not be achieved by such an arrangement. The theoretical analysis further shows that if the submicron particles and the large collector particles were charged with opposite polarity, significant removal of the submicron particles could be obtained. The second application of agglomeration considered in this thesis is predicting/controlling nanoparticle size in the gas-to-particle aerosol route to material synthesis. In a typical material reactor, a precursor vapor reacts to form molecules of the desired material. In a cooling environment, a particulate phase forms, the dynamics of which are determined by the rates of

  18. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.; Orr, L.

    1993-01-01

    The various components of the high-energy physics research program at the University of Rochester are presented. (I)Fixed-target experimentation at FNAL includes studies of direct photon production by p and π on H, Be, and Cu, and hybrid mesons and other physics issues in Coulomb excitation at high energies. (II)The status of the GEM (Gammas, Electrons, and Muons) Experiment at the SSC is given. (III)The D-Zero experiment at FNAL is reviewed. (IV)Deep inelastic lepton--nucleon scattering experiments are summarized: electron scattering experiments at SLAC, FNAL neutrino quad triplet runs, FNAL neutrino sign selected experiments, and SDC cosmic ray test and test beam calibration. (V)Studies of nonlinear QED at SLAC concentrated on a study of QED at critical field strength in intense laser--high-energy electron collisions. (VI)Development work on the Collider Detector at Fermilab (CDF) emphasized the CDF silicon vertex detector, the end plug calorimeter, and the SDC tile/fiber calorimetry. (VII)The theoretical physics effort is sketched

  19. Theoretical study of defect properties in metals

    International Nuclear Information System (INIS)

    Sindzingre, P.

    1987-01-01

    Several characteristic properties (formation and migration enthalpies and volumes, dipole tensors, effects on shear elastic constants) of several point defects (vacancy, divacancy, interstitial, di-interstitial) in different metals: f.c.c. metals (Al, Cu, Ag, Au), h.c.p. metals (Be, Mg, Zn, Cd, Na, Co, Ti, Zr), b.c.c. metals (Li, Na, K, Rb, Cs) have been calculated. The calculated properties are evaluated from static computations performed with pair potentials derived from pseudo-potential theory (for simple or noble metals) or deduced empirically. Results are compared with available experimental data with previous theoretical works. The first part of this work where we have studied point defects properties in f.c.c. metals lead us to suggest a more convincing interpretation of X-ray scattering and elastic relation measurements concerning interstitials in Al and Cu, and a new interpretation for X-ray scattering measurements concerning di-interstitials in Al. In the second part, devoted to h.c.p. metals we are brought to propose for each studied metal the interstitial configurations which yield the best agreement with experimental results. The third part, devoted to the study of point defects in alkalin b.c.c. metals lead us to interpret self-diffusion in these metals with the assumption of a simultaneous contribution of monovacancies, divacancies and interstitials [fr

  20. Theoretical and experimental study of thermoacoustic engines

    Science.gov (United States)

    Raspet, Richard; Bass, Henry E.; Arnott, W. P.

    1992-12-01

    A three year study of thermoacoustic engines operating as prime movers and refrigerators was completed. The major thrust of this effort was the use and theoretical description of ceramic honeycomb structures as the active element in thermoacoustic engines. An air-filled demonstration prime mover was constructed and demonstrated at Acoustical Society of America and IEE meetings. A helium-filled test prime mover was designed and built an is being employed in studies of the threshold of oscillation as a function of temperature difference and pressure. In addition, acoustically based theories of the thermoacoustic engine have been developed and tested for a parallel plate stack at the Naval Postgraduate School and for a honeycomb stack at the University of Mississippi. Most of this work is described in detail in the attached publications. In this report we will give an overview of the research completed to date and its relationship to work performed at the Naval Postgraduate School and to future work at the University of Mississippi.

  1. Theoretical aspects of coping strategies study

    OpenAIRE

    Kabiyeva, M.; Kasen, G. A.

    2015-01-01

    In article based on a thorough analysis of classical and modern foreign and domestic literature examines the notion of coping strategies, approaches to the understanding of coping. Theoretically proved that coping is an individual way to interact with the situation according to its own logic, psychological capabilities and its importance in human life, the level of development of coping resources provides a successful adaptation to stress. From the analysis of theoretical literature, we saw t...

  2. Theoretical Study of a Spherical Plasma Focus

    Science.gov (United States)

    Ay, Yasar

    A theoretical model is developed for two concentric electrodes spherical plasma focus device in order to investigate the plasma sheath dynamics, radiative emission, and the ion properties. The work focuses on the model development of the plasma sheath dynamics and its validation, followed by studying of the radiation effects and the beam-ion properties in such unique geometry as a pulsed source for neutrons, soft and hard x-rays, and electron and ion beams. Chapter 1 is an introduction on fusion systems including plasma focus. Chapter 2 is an extensive literature survey on plasma focus modeling and experiments including the various radiations and their mechanism. Chapter 3 details modeling and validation of the plasma sheath dynamics model with comparison between hydrogen, deuterium, tritium and deuterium-tritium mixture for the production of pulsed neutrons. Chapter 4 is a study of the radiative phase, in which neutron yield is investigated, as well as the predicted beam-ion properties. Chapter 5 summarizes and discusses the results. Chapter 6 provides concluding remarks and proposed future works. The phases of the developed model are the rundown phase I, rundown phase II, the reflected phase and a radiative phase. The rundown phase I starts immediately after the completion of the gas breakdown and ends when the current sheath reaches the equator point of the spherical shape. Then immediately followed by rundown phase II to start and it ends when the shock front hits the axis, which is the beginning of the reflected shock phase. Reflected shock front moves towards the incoming current sheath and meets it which is both the end of the reflected shock phase and the beginning of the radiative phase. After the reflected shock front and the current sheath meet, the current sheath continues to move radially inward by compressing the produced plasma column until it reaches the axis. Since the discharge current contains important information about the plasma dynamic

  3. Theoretical study of conjugated porphyrin polymers

    DEFF Research Database (Denmark)

    Pedersen, T.G.; Lynge, T.B.; Kristensen, P.K.

    2005-01-01

    for these applications. From a theoretical analysis of excitons in long metalloporphyrin chains, we demonstrate that the binding energy is much lower than in usual conjugated polymers. Our calculated absorption spectra are in good agreement with measurements. (c) 2004 Elsevier B.V. All rights reserved....

  4. Theoretical study of the electron paramagnetic resonance ...

    Indian Academy of Sciences (India)

    Abstract. The electron paramagnetic resonance (EPR) parameters (the g factors, hy- perfine structure constants and the superhyperfine parameters) for the tetragonal Ir2+ centre in NaCl are theoretically investigated from the perturbation formulas of these parameters for a 5d7 ion in tetragonally elongated octahedra.

  5. EXPERIMENT AL AND THEORETICAL STUDY OF PRECAST ...

    African Journals Online (AJOL)

    In such type of construction, the fresh concrete can be directly poured on the precast beam elements and hollow concrete blocks, which bridge the space between the beams. However, the safety of such construction must be ensured through theoretical investigations supported by experimental verifications. The purpose of ...

  6. Theoretical Model for Volume Fraction of UC, 235U Enrichment, and Effective Density of Final U 10Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); McGarrah, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)

    2016-04-12

    The purpose of this document is to provide a theoretical framework for (1) estimating uranium carbide (UC) volume fraction in a final alloy of uranium with 10 weight percent molybdenum (U-10Mo) as a function of final alloy carbon concentration, and (2) estimating effective 235U enrichment in the U-10Mo matrix after accounting for loss of 235U in forming UC. This report will also serve as a theoretical baseline for effective density of as-cast low-enriched U-10Mo alloy. Therefore, this report will serve as the baseline for quality control of final alloy carbon content

  7. A Correlational Study of Students' Theoretical and Practical

    African Journals Online (AJOL)

    Galadanci & Mukhtar

    the examinations are theoretical; either in the form of multiple choice questions or essay questions. In a few subjects, such as. Physics, Chemistry and Biology, where the course of study has a substantial practical component over and above the theoretical component, students are given both theoretical and practical.

  8. Theoretical and experimental study of fenofibrate and simvastatin

    Science.gov (United States)

    Nicolás Vázquez, Inés; Rodríguez-Núñez, Jesús Rubén; Peña-Caballero, Vicente; Ruvalcaba, Rene Miranda; Aceves-Hernandez, Juan Manuel

    2017-12-01

    Fenofibrate, an oral fibrate lipid lowering agent, and simvastatin, which reduces plasma levels of low-density lipoprotein cholesterol, are active pharmaceutical ingredients (APIs), currently in the market. We characterized these APIs by thermal analysis and conducted X-ray powder diffraction techniques. Studies should be carried out in the formulation stage before the final composition of a polypill may be established. Thus, it was found in thermochemical studies that both compounds present no chemical interactions in an equimolar mixture of solid samples at room temperature. Theoretical studies were employed to determine possible interactions between fenofibrate and simvastatin. A very weak intramolecular hydrogen bond is formed between the hydroxyl group (O5H5) of the simvastatin with chlorine and carbonyl group (C11O4, C1O2) of the fenofibrate molecule. These weak energy hydrogen bonds have no effect on the chemical stability of the compounds studied. The results were obtained using Density Functional Theory methods; particularly the BPE1BPE and B3LYP functional and 6-31++G** basis set. The values of energy show good approximation when are compared with similar calculations previously reported. Infrared spectra of monomers and dimers were obtained via theoretical calculations.

  9. Theoretical study of near-threshold electron-molecule scattering

    International Nuclear Information System (INIS)

    Morrison, M.A.

    1989-01-01

    We have been engaged in carrying out a foundation study on problems pertaining to near-threshold nuclear excitations in e-H 2 scattering. The primary goals of this study are: to investigate the severity and nature of the anticipated breakdown of the adiabatic-nuclei (AN) approximation, first for rotation only (in the rigid-rotator approximation), and then for vibration; to determine a data base of accurate ab initio cross sections for this important system; to implement and test accurate, computationally-tractable model potentials for exchange and polarization effects; and to begin the exploration of alternative scattering theories for near-threshold collisions. This study has provided a well-defined theoretical context for our future investigations. Second, it has enabled us to identify and quantify several serious problems in the theory of near-threshold electron-molecule scattering that demand attention. And finally, it has led to the development of some of the theoretical and computational apparatus that will form the foundation of future work. In this report, we shall review our progress to date, emphasizing work completed during the current contract year. 17 refs., 5 figs., 1 tab

  10. Studies in theoretical high energy particle physics

    International Nuclear Information System (INIS)

    Aratyn, H.; Brekke, L.; Keung, Wai-Yee; Sukhatme, U.

    1993-01-01

    Theoretical work on the following topics is briefly summarized: symmetry structure of conformal affine Toda model and KP hierarchy; solitons in the affine Toda and conformal affine Toda models; classical r-matrices and Poisson bracket structures on infinite-dimensional groups; R-matrix formulation of KP hierarchies and their gauge equivalence; statistics of particles and solitons; charge quantization in the presence of an Alice string; knotting and linking of nonabelian flux; electric dipole moments; neutrino physics in gauge theories; CP violation in the high energy colliders; supersymmetric quantum mechanics; parton structure functions in nuclei; dual parton model. 38 refs

  11. Theoretical studies in elementary particle physics

    International Nuclear Information System (INIS)

    Collins, J.

    1994-01-01

    This is a report on research conducted at Penn State University under grant number DE-FG02-90ER-40577, from November 1992 to present. The author is a member of the CTEQ collaboration (Coordinated Theoretical and Experimental Project on Quantitative QCD). Some of the work in CTEQ is described in this report. Topics which the authors work has touched include: polarized hard scattering; hard diffraction; small x and perturbative pomeron physics; gauge-invariant operators; fundamental QCD; heavy quarks; instantons and deep inelastic scattering; non-perturbative corrections to τ decay

  12. Solar pond conception - experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Huseyin [Zonguldak Karaelmas Univ., Technical Education Faculty, Karabuk (Turkey); Halici, Fethi [Sakarya Univ., Mechanical Engineering Dept., Adapazari (Turkey); Binark, A. Korhan [Marmara Univ., Technical Education Faculty, Istanbul (Turkey)

    2000-07-01

    A one dimensional transient mathematical model for predicting the thermal performance of the salt gradient solar pond is developed and presented. In this paper, the natural solar ponds and different artificial solar pond systems found in the literature are introduced. Necessary modifications are made on the experimental stand located in Istanbul Technical University, the experimental stand is introduced and natural phenomena produced in the pond by the different solar pond variations under natural conditions are observed. In the theoretical work based on a one dimensional unsteady state heat conduction model with internal heat generation, the energy and mass balance equations for the upper convective zone, the non-convective zone and the lower convective zone, all of which form the solar pond, are written in terms of differential equations. These equations are solved analytically and numerically. The results obtained from the analysis are compared with the experimental results. The temperature and the concentration profiles are separately presented in the figures. (Author)

  13. Advanced Design Studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Don [Rensselaer Polytechnic Institute, Troy, NY (United States)

    2012-12-01

    The ARIES-CS project was a multi-year multi-institutional project to assess the feasibility of a compact stellarator as a fusion power plant. The work herein describes efforts to help design one aspect of the device, the divertor, which is responsible for the removal of particle and heat flux from the system, acting as the first point of contact between the magnetically confined hot plasma and the outside world. Specifically, its location and topology are explored, extending previous work on the sub ject. An optimized design is determined for the thermal particle flux using a suite of 3D stellarator design codes which trace magnetic field lines from just inside the confined plasma edge to their strike points on divertor plates. These divertor plates are specified with a newly developed plate design code. It is found that a satisfactory thermal design exists which maintains the plate temperature and heat load distribution below tolerable engineering limits. The design is unique, including a toroidal taper on the outboard plates which was found to be important to our results. The maximum thermal heat flux for the final design was 3.61 M W/m2 and the maximum peaking factor was 10.3, below prescribed limits of 10 M W/m2 and 15.6, respectively. The median length of field lines reaching the plates is about 250 m and their average angle of inclination to the surface is 2 deg. Finally, an analysis of the fast alphas, resulting from fusion in the core, which escape the plasma was performed. A method is developed for obtaining the mapping from magnetic coordinates to real-space coordinates for the ARIES-CS. This allows the alpha exit locations to be identified in real space for the first time. These were then traced using the field line algorithm as well as a guiding center routine accounting for their mass, charge, and specific direction and energy. Results show that the current design is inadequate for accommodating the alpha heat flux, capturing at most 1/3 of lost alphas

  14. Theoretical studies of the C4 molecule

    International Nuclear Information System (INIS)

    Ritchie, J.P.; King, H.F.; Young, W.S.

    1985-01-01

    Optimized geometries and relative energies for three states of the C 4 molecule have been obtained from single-reference configuration interaction (SRCI) calculations. At the SRCI level, a rhombic form is calculated to lie 1.1 kcal below the triplet form; consideration of the Davidson correction reduces this difference to 0.4 kcal, while more complete basis sets are expected to increase the difference only by about 0.2 kcal. Consideration of these effects and difference in zero-point energy leads to a final estimated splitting of 1.2 kcal, favoring the rhombus. To aid the determination of the ground state, preliminary estimates of the lowest optical transitions were obtained from SRCI calculations and vibrational frequencies were obtained from SCF calculations. Comparison of the calculated results with experimentally obtained spectra suggest the possibility that both the linear triplet and the rhombus may have already been observed. 19 refs., 4 figs., 4 tabs

  15. [Theoretical elementary particle studies.] Final report, September 1983-July 1985

    International Nuclear Information System (INIS)

    Collins, J.C.

    1985-01-01

    The work done during the period September 1983 to July 1985 covers several areas of the theory of the strong interactions of elementary particles, mostly in the area characterized as 'perturbative QCD'. The specific topics are: the proof of factorization for hard processes, such as the Drell-Yan process; calculation of transverse-mementum distributions for these processes; investigation of the small-x region; demonstration of the applicability of perturbative QCD (quantum chromodynamics) to the production of heavy quarks; and improved methods of calculation of the effects of heavy quarks in hard processes, and in particular of their distribution functions in hadrons ('structure functions'). 31 refs

  16. Theoretical Studies of Hydrogen Storage Alloys.

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Hannes

    2012-03-22

    Theoretical calculations were carried out to search for lightweight alloys that can be used to reversibly store hydrogen in mobile applications, such as automobiles. Our primary focus was on magnesium based alloys. While MgH{sub 2} is in many respects a promising hydrogen storage material, there are two serious problems which need to be solved in order to make it useful: (i) the binding energy of the hydrogen atoms in the hydride is too large, causing the release temperature to be too high, and (ii) the diffusion of hydrogen through the hydride is so slow that loading of hydrogen into the metal takes much too long. In the first year of the project, we found that the addition of ca. 15% of aluminum decreases the binding energy to the hydrogen to the target value of 0.25 eV which corresponds to release of 1 bar hydrogen gas at 100 degrees C. Also, the addition of ca. 15% of transition metal atoms, such as Ti or V, reduces the formation energy of interstitial H-atoms making the diffusion of H-atoms through the hydride more than ten orders of magnitude faster at room temperature. In the second year of the project, several calculations of alloys of magnesium with various other transition metals were carried out and systematic trends in stability, hydrogen binding energy and diffusivity established. Some calculations of ternary alloys and their hydrides were also carried out, for example of Mg{sub 6}AlTiH{sub 16}. It was found that the binding energy reduction due to the addition of aluminum and increased diffusivity due to the addition of a transition metal are both effective at the same time. This material would in principle work well for hydrogen storage but it is, unfortunately, unstable with respect to phase separation. A search was made for a ternary alloy of this type where both the alloy and the corresponding hydride are stable. Promising results were obtained by including Zn in the alloy.

  17. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin [Univ. of Rochester, NY (United States)

    2012-10-04

    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  18. Theoretical study of nitride short period superlattices

    Science.gov (United States)

    Gorczyca, I.; Suski, T.; Christensen, N. E.; Svane, A.

    2018-02-01

    Discussion of band gap behavior based on first principles calculations of electronic band structures for various short period nitride superlattices is presented. Binary superlattices, as InN/GaN and GaN/AlN as well as superlattices containing alloys, as InGaN/GaN, GaN/AlGaN, and GaN/InAlN are considered. Taking into account different crystallographic directions of growth (polar, semipolar and nonpolar) and different strain conditions (free-standing and pseudomorphic) all the factors influencing the band gap engineering are analyzed. Dependence on internal strain and lattice geometry is considered, but the main attention is devoted to the influence of the internal electric field and the hybridization of well and barrier wave functions. The contributions of these two important factors to band gap behavior are illustrated and estimated quantitatively. It appears that there are two interesting ranges of layer thicknesses; in one (few atomic monolayers in barriers and wells) the influence of the wave function hybridization is dominant, whereas in the other (layers thicker than roughly five to six monolayers) dependence of electric field on the band gaps is more important. The band gap behavior in superlattices is compared with the band gap dependence on composition in the corresponding ternary and quaternary alloys. It is shown that for superlattices it is possible to exceed by far the range of band gap values, which can be realized in ternary alloys. The calculated values of the band gaps are compared with the photoluminescence emission energies, when the corresponding data are available. Finally, similarities and differences between nitride and oxide polar superlattices are pointed out by comparison of wurtzite GaN/AlN and ZnO/MgO.

  19. Final report on case studies

    DEFF Research Database (Denmark)

    Ljungberg, Daniel; McKelvey, Maureen; Lassen, Astrid Heidemann

    2012-01-01

    Case study as a research design means investigating a single or multiple instance(s) or setting(s) (i.e. a case) and its entire context to explain a phenomenon and its processes. This is achieved through detailed understanding, usually comprised of multiple sources of information. In this way, ca...

  20. Skid resistance study : final report.

    Science.gov (United States)

    1977-06-01

    This is a report of a research project involving, in Phase I, the skid resistance of asphaltic concrete overlays. Phase II is a report of a pilot study set up in order to determine the best way to perform a skid resistance inventory of the highway ne...

  1. A correlational study of students' theoretical and practical ...

    African Journals Online (AJOL)

    A correlational study of students' theoretical and practical examinations scores in computer applications courses in Bayero University Kano. ... Science World Journal ... In other words, for a student to do well in any of the courses, he/she must perform well in both the theoretical and practical aspects of the examination.

  2. THEORETICAL STUDY OF THE CATALYTIC DESULFURIZATION ...

    African Journals Online (AJOL)

    a

    In the present study we have submitted the dihydrothiiren (Figure 1b), the methylthiiren (Figure 1c) and the methyldihydrothiiren (Figure 1d) to the same process before proceeding to their desulfurization behaviour in order to propose the sulfur atom elimination mechanism while studying methyl group influence on the thiiren ...

  3. Laser fusion study. Final report

    International Nuclear Information System (INIS)

    1975-06-01

    The following appendices are included: (1) sensor performance calculation techniques, (2) focus sensing, (3) purchased item data, (4) pointing and focusing configuration tradeoff studies, (5) false start centering sensor, (6) RCA application notes on quad delection, (7) elliptical flex pivot analysis, (8) servo mirrors cross coupling, (9) optical misalignment analysis, (10) stress induced birefrigent quarter-wave retarder, (11) data bulletin on incramute damping alloy, (12) the utilization of stepping motors, and (13) computer program listing for stepper motor load simulation

  4. Theoretical Study of Semiconductor Laser under Modulation

    Science.gov (United States)

    Boukari, O.; Hassine, L.; Dherbecourt, P.; Latry, O.; Ketata, M.; Bouchriha, H.

    2007-09-01

    In this paper we present a description of the chirp induced in a direct modulated DFB laser. Our study is follows two different approaches. The first approach is based on a resolution of the rate equations of laser; the second, on a simulation of a heterodyne system with the Optisystem software. This study enables us to visualize the chirp in the RF field. We also characterize it according to the injection current i(t) parameters, such as the amplitude and the frequency of the modulation. The aim of our study is to choose the appropriate values of these parameters, in order to use the direct modulated DFB laser as an optical tunable source for Coherent Optical Frequency Domain Reflectometry technique (C-OFDR). We demonstrate that the optical frequency of these lasers can be controlled via the injection current i(t) and it can be linearly swept (chirped) over some tens of gigahertz.

  5. Theoretical studies on energetic materials bearing pentaflurosulphyl ...

    Indian Academy of Sciences (India)

    Heats of formation (HOF) for a series of energetic materials containing SF5 group were studied by density functional theory. Results show that HOFs increase with the augmention of field effects of substituted groups. Addition of furazan or furoxan ring increases HOF of the energetic materials. All the SF5-containing ...

  6. A Theoretical Study of Leading Edge Noise

    Science.gov (United States)

    2008-05-01

    measurements of the noise radiated from a number of different airfoils made as -part of a companion study at Virginia lech . It was concluded that the...giving, at a distance r from the blade, and at an angle 9 to the direction of the unsteady loading, the sound spectrum as Spp(co)=( cocos &4itrcc) 2SLL

  7. Theoretical studies on the conformations of selenamides

    Indian Academy of Sciences (India)

    Unknown

    selenols, selenones, selenoamides, selenonium ylides, selenonium imides etc. have been studied in comparison with organosulphur compounds 1. Compounds containing Se–N bonds are rare. Flemmang et al 2 have reported the generation of nitrile N-selenides in the gas phase, which have Se–N ionic interactions.

  8. A Theoretical Study of Landing Mat Behavior

    Science.gov (United States)

    1969-07-01

    Waterways Experiment Station (WES) under Contract DACA 39-67-C-oohh, during the period July 1967 to March 1969. The study was conducted as a part of the...required functional relationship. If the functional relationship was to apply, of necessity , it had to satisfy each set of- data. Thus in order to

  9. Theoretical studies on energetic materials bearing pentaflurosulphyl

    Indian Academy of Sciences (India)

    Heats of formation (HOF) for a series of energetic materials containing SF5 group were studied by density functional theory. Results show that HOFs increase with the augmention of field effects of substituted groups. Addition of furazan or furoxan ring increases HOF of the energetic materials. All the SF5-containing ...

  10. Global Leadership Study: A Theoretical Framework

    Science.gov (United States)

    Perkins, Anne W.

    2009-01-01

    Traditional leadership theory and research courses do not adequately prepare students for cross-cultural leadership. This article notes six premises of Western theories and demonstrates the limitations of these premises in non-Western settings. A framework for the study of cross-cultural leadership, The Global Leadership-Learning Pyramid, is…

  11. Theoretical and experimental studies on the foundation theoretical and experimental studies on the foundation of mesomechanics

    Science.gov (United States)

    Chudnovsky, A.; Wu, S.

    1992-06-01

    The report summarizes a closely coupled experimental and theoretical investigation of various stages of Fracture Process: (1) accumulation of 'damage' on submicroscopical and microscopical scales leading to crack initiation; (2) slow (subcritical) crack growth and an evolution of the damage zone; (3) transition to dynamic crack growth and the catastrophic failure. The experimental part of the program is focused on the observation and quantitative characterization of damage preceding and accompanying crack initiation and growth. A special experimental setup for studying the fracture process under variable stress field is reported in Chapter 2. A leading role of crack-damage interaction in fracture process is well documented. A new formalism for solution of crack-microcrack array interaction problem and its successful implementation in the evaluation of crack layer driving forces is presented in Chapter 3. A new model of the process zone, which generalizes the well-known Dagdale-Barenblatt model is presented in Chapter 4. A new measure for material toughness and the prediction of R-curve behavior illustrate the practical application of our model. Experimental examinations of our model under various test conditions are reported in Chapters 4, 5 and 6. The development of the constitutive equations for Crack Layer evolution and their experimental examinations under stress relaxation, fatigue and creep conditions are reported in Chapters 5 and 6. An accelerated test procedure and the formulation of crack layer instability criteria as a substitution for the conventional fracture toughness parameters are also discussed in Chapter 6.

  12. Theoretical and experimental studies of thermolysin inhibition

    OpenAIRE

    Wuxiuer, Yimingjiang

    2008-01-01

    Zinc-metalloproteinases play a key role in the biosythesis and metabolism of different bioactive peptides. As a member of zinc-metalloproteinases, thermolysin has served as a model system to study the inhibition mechanism of other metalloproteinases. Inhibitors of thermolysin have considerable potential as therapeutic agents. In the present master thesis, docking calculations were performed and reported for 25 potent non-peptidal thermolysin inhibitors retrieved from literatures. Docking sof...

  13. THEORETICAL CONCEPT OF JOB SATISFACTION - A STUDY

    OpenAIRE

    Dr. A. Thangaswamy; D.Thiyagaraj

    2017-01-01

    Job satisfaction is one of the important factors that have drawn attention of the organization as well as academicians. In view of the rising competition as a result of globalisation, managers have placed great importance on the construct of job satisfaction. This may be due to the findings of many studies that job satisfaction is a significant determinant of organizational commitment. Highly satisfied employees will exert extra effort and contribute positively to the effectiveness and effici...

  14. Theoretical and experimental studies of elementary particles

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Olsen, S.L.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.

    1991-01-01

    This report discusses: Fixed target experimentation at Fermilab; the D-zero collider experiment at Fermilab; deep inelastic lepton nucleon scattering; non-accelerator experiments and non-linear QED; the AMY experiment at TRISTAN and other activities at KEK; the collider detector at Fermilab; laser switched linac; preparations for experiments at the SSC; search for massive stable particles; and the Advanced Study Institute on techniques and concepts of high energy physics

  15. Theoretical Studies of Elementary Hydrocarbon Species and Their Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Wesley D. [University of Georgia, Department of Chemistry and Center for Computational Quantum Chemistry; Schaefer, Henry F. [University of Georgia, Center for Computational Quantum Chemistry

    2018-04-08

    The research program supported by this DOE grant carried out both methodological development and computational applications of first-principles theoretical chemistry based on quantum mechanical wavefunctions, as directed toward understanding and harnessing the fundamental chemical physics of combustion. To build and refine the world’s database of thermochemistry, spectroscopy, and chemical kinetics, predictive and definitive computational methods are needed that push the envelope of modern electronic structure theory. The application of such methods has been made to gain comprehensive knowledge of the paradigmatic reaction networks by which the n- and i-propyl, t-butyl, and n-butyl radicals are oxidized by O2. Numerous ROO and QOOH intermediates in these R + O2 reaction systems have been characterized along with the interconnecting isomerization transition states and the barriers leading to fragmentation. Other combustion-related intermediates have also been studied, including methylsulfinyl radical, cyclobutylidene, and radicals derived from acetaldehyde and vinyl alcohol. Theoretical advances have been achieved and made available to the scientific community by implementation into PSI4, an open-source electronic structure computer package emphasizing automation, advanced libraries, and interoperability. We have pursued the development of universal explicitly correlated methods applicable to general electronic wavefunctions, as well as a framework that allows multideterminant reference functions to be expressed as a single determinant from quasiparticle operators. Finally, a rigorous analytical tool for correlated wavefunctions has been created to elucidate dispersion interactions, which play essential roles in many areas of chemistry, but whose effects are often masked and enigmatic. Our research decomposes and analyzes the coupled-cluster electron correlation energy in molecular systems as a function of interelectronic distance. Concepts

  16. Theoretical study of HBeO

    International Nuclear Information System (INIS)

    Zaidi, A.; Lahmar, S.; Lakhdar, Z. Ben; Rosmus, P.; Chambaud, G.

    2006-01-01

    Using multi-reference configuration interaction (MRCI) and coupled-cluster RCCSD(T) ab initio methods three-dimensional potential energy surfaces (PES) have been generated for the X 2 Π and A 2 Σ + states of HBeO. The two components of the X 2 Π electronic ground state form a linear-linear Renner-Teller pair. The HBeO structure is calculated to lie 11,917cm -1 above the BeOH isomer. A barrier on the A' PES of 10,920cm -1 relative to the HBeO minimum does not permit a spontaneous rearrangement. From variational Renner-Teller calculations the rovibronic levels of the X 2 Π state of the HBeO radical have been evaluated for J=12andJ=32. The eigenstates can not be unequivocally assigned by harmonic quantum numbers due to anharmonic resonances involving all three vibrational modes. In contrast with previous studies A 2 Σ + state is calculated above the X 2 Π (T e =9389cm -1 ). For some higher doublet and quartet states of BeOH and HBeO, MRCI vertical electronic transition energies are reported

  17. Theoretical studies of homogeneous catalysts mimicking nitrogenase.

    Science.gov (United States)

    Sgrignani, Jacopo; Franco, Duvan; Magistrato, Alessandra

    2011-01-10

    The conversion of molecular nitrogen to ammonia is a key biological and chemical process and represents one of the most challenging topics in chemistry and biology. In Nature the Mo-containing nitrogenase enzymes perform nitrogen 'fixation' via an iron molybdenum cofactor (FeMo-co) under ambient conditions. In contrast, industrially, the Haber-Bosch process reduces molecular nitrogen and hydrogen to ammonia with a heterogeneous iron catalyst under drastic conditions of temperature and pressure. This process accounts for the production of millions of tons of nitrogen compounds used for agricultural and industrial purposes, but the high temperature and pressure required result in a large energy loss, leading to several economic and environmental issues. During the last 40 years many attempts have been made to synthesize simple homogeneous catalysts that can activate dinitrogen under the same mild conditions of the nitrogenase enzymes. Several compounds, almost all containing transition metals, have been shown to bind and activate N₂ to various degrees. However, to date Mo(N₂)(HIPTN)₃N with (HIPTN)₃N= hexaisopropyl-terphenyl-triamidoamine is the only compound performing this process catalytically. In this review we describe how Density Functional Theory calculations have been of help in elucidating the reaction mechanisms of the inorganic compounds that activate or fix N₂. These studies provided important insights that rationalize and complement the experimental findings about the reaction mechanisms of known catalysts, predicting the reactivity of new potential catalysts and helping in tailoring new efficient catalytic compounds.

  18. Theoretical Studies of Homogeneous Catalysts Mimicking Nitrogenase

    Directory of Open Access Journals (Sweden)

    Alessandra Magistrato

    2011-01-01

    Full Text Available The conversion of molecular nitrogen to ammonia is a key biological and chemical process and represents one of the most challenging topics in chemistry and biology. In Nature the Mo-containing nitrogenase enzymes perform nitrogen ‘fixation’ via an iron molybdenum cofactor (FeMo-co under ambient conditions. In contrast, industrially, the Haber-Bosch process reduces molecular nitrogen and hydrogen to ammonia with a heterogeneous iron catalyst under drastic conditions of temperature and pressure. This process accounts for the production of millions of tons of nitrogen compounds used for agricultural and industrial purposes, but the high temperature and pressure required result in a large energy loss, leading to several economic and environmental issues. During the last 40 years many attempts have been made to synthesize simple homogeneous catalysts that can activate dinitrogen under the same mild conditions of the nitrogenase enzymes. Several compounds, almost all containing transition metals, have been shown to bind and activate N2 to various degrees. However, to date Mo(N2(HIPTN3N with (HIPTN3N= hexaisopropyl-terphenyl-triamidoamine is the only compound performing this process catalytically. In this review we describe how Density Functional Theory calculations have been of help in elucidating the reaction mechanisms of the inorganic compounds that activate or fix N2. These studies provided important insights that rationalize and complement the experimental findings about the reaction mechanisms of known catalysts, predicting the reactivity of new potential catalysts and helping in tailoring new efficient catalytic compounds.

  19. Theoretical and Experimental Studies in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James [Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy

    2017-03-08

    . We note also that PBPL graduates remain as close elaborators for the program after leaving UCLA. The UCLA PBPL program is a foremost developer of on-campus facilities, such as the Neptune and Pegasus Laboratories, providing a uniquely strong environment for student-based research. In addition, the PBPL is a strong user of off-campus national lab facilities, such as SLAC FACET and NLCTA, and the BNL ATF. UCLA has also vigorously participated in the development of these facilities. The dual emphases on off- and on-campus opportunities permit the PBPL to address in an agile way a wide selection of cutting-edge research topics. The topics embraced by this proposal illustrate this program aspect well. These include: GV/m dielectric wakefield acceleration/coherent Cerenkov radiation experiments at FACET (E-201) and the ATF; synergistic laser-excited dielectric accelerator and light source development; plasma wakefield (PWFA) experiments on “Trojan horse” ionization injection (FACET E-210), quasi-nonlinear PWFA at BNL and the production at Neptune high transformer ratio plasma wakes; the inauguration of a new type of RF photoinjector termed “hybrid” at UCLA, and application to PWFA; space-charge dominated beam and cathode/near cathode physics; the study of advanced IFEL systems, for very high energy gain and utilization of novel OAM modes; the physcis of inverse Compton scattering (ICS), with applications to e+ production and γγ colliders; electron diffraction; and advanced beam diagnostics using coherent imaging techniques. These subjects are addressed under the leadership of PBPL director Prof. James Rosenzweig in Task A, and Prof. Pietro Musumeci in Task J, which was initiated following his OHEP Outstanding Junior Investigator award.

  20. Theoretical study of nuclear physics with strangeness at Nankai University

    International Nuclear Information System (INIS)

    Ning Pingzhi

    2007-01-01

    Theoretical study of nuclear physics with strangeness from the nuclear physics group at Nankai university is briefly introduced. Theoretical calculations on hyperon mean free paths in nuclear medium have been done. The other 4 topics in the area of strangeness nuclear physics are the effect of different baryon impurities in nucleus, the heavy flavored baryon hypernuclei, the eta-mesons in nuclear matter and the properties of kaonic nuclei. (authors)

  1. Experimental and theoretical study of magnetohydrodynamic ship models.

    Science.gov (United States)

    Cébron, David; Viroulet, Sylvain; Vidal, Jérémie; Masson, Jean-Paul; Viroulet, Philippe

    2017-01-01

    Magnetohydrodynamic (MHD) ships represent a clear demonstration of the Lorentz force in fluids, which explains the number of students practicals or exercises described on the web. However, the related literature is rather specific and no complete comparison between theory and typical small scale experiments is currently available. This work provides, in a self-consistent framework, a detailed presentation of the relevant theoretical equations for small MHD ships and experimental measurements for future benchmarks. Theoretical results of the literature are adapted to these simple battery/magnets powered ships moving on salt water. Comparison between theory and experiments are performed to validate each theoretical step such as the Tafel and the Kohlrausch laws, or the predicted ship speed. A successful agreement is obtained without any adjustable parameter. Finally, based on these results, an optimal design is then deduced from the theory. Therefore this work provides a solid theoretical and experimental ground for small scale MHD ships, by presenting in detail several approximations and how they affect the boat efficiency. Moreover, the theory is general enough to be adapted to other contexts, such as large scale ships or industrial flow measurement techniques.

  2. Experimental and theoretical study of magnetohydrodynamic ship models.

    Directory of Open Access Journals (Sweden)

    David Cébron

    Full Text Available Magnetohydrodynamic (MHD ships represent a clear demonstration of the Lorentz force in fluids, which explains the number of students practicals or exercises described on the web. However, the related literature is rather specific and no complete comparison between theory and typical small scale experiments is currently available. This work provides, in a self-consistent framework, a detailed presentation of the relevant theoretical equations for small MHD ships and experimental measurements for future benchmarks. Theoretical results of the literature are adapted to these simple battery/magnets powered ships moving on salt water. Comparison between theory and experiments are performed to validate each theoretical step such as the Tafel and the Kohlrausch laws, or the predicted ship speed. A successful agreement is obtained without any adjustable parameter. Finally, based on these results, an optimal design is then deduced from the theory. Therefore this work provides a solid theoretical and experimental ground for small scale MHD ships, by presenting in detail several approximations and how they affect the boat efficiency. Moreover, the theory is general enough to be adapted to other contexts, such as large scale ships or industrial flow measurement techniques.

  3. STUDY OF THE SEMI-THEORETICAL RELATION OF THE ...

    African Journals Online (AJOL)

    ABSTRACT. This study has for objective to study the theoretical relation of the hydraulic jump by sill, evolving in an U-shaped channel, with a rough bed. Functional relations, in non- dimensional form, relating the jump characteristics, seeming the effect of the bed's roughness, are obtained. A comparative study with the ...

  4. Optical graphene quantum dots gas sensors: Theoretical study

    Science.gov (United States)

    Raeyani, D.; Shojaei, S.; Ahmadi-Kandjani, S.

    2018-02-01

    In this work, we theoretically studied the changes of graphene quantum dots (GQD) absorption spectra under the influence of different gases to indicate optical gas sensing features of GQDs. The adsorption of gas molecules such as CO2, N2 and Ar on GQDs have been theoretically investigated through time-dependent density functional theory (TDDFT) calculations. Our study revealed that UV-Vis absorption spectrum of GQDs in the presence of CO2 undergoes considerable changes than that of N2 and Ar. The shift of maximum absorption wavelength for adsorption of CO2, N2 and Ar in same distance from GQD in addition to density of state (DOS) and orbital analyses have been obtained. To verify our theoretical results, comparison with experimental study has been done and good agreement has been observed. Comparing with electrical property of GQD, optical properties showed an efficient tool to be implemented in gas adsorption and paves the way towards GQD optical gas sensors.

  5. Theoretical study on β-aminoacroleine; Density functional theory ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 124; Issue 3. Theoretical study on β-aminoacroleine; Density functional theory, atoms in molecules theory and natural bond orbitals studies. Heidar Raissi Mehdi Yoosefian Effat Moshfeghi Farzaneh Farzad. Volume 124 Issue 3 May 2012 pp 731-739 ...

  6. Theoretical studies on proton transfer reaction of 3 (5)-substituted ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 1. Theoretical studies on proton transfer reaction of 3(5)-substituted pyrazoles ... Abstract. The inter and intra molecular proton transfer reactions of a series of pyrazole derivatives have been studied by using density functional theory (DFT) andMP2 methods ...

  7. Theoretical study (ab initio and DFT methods) on acidic dissociation ...

    African Journals Online (AJOL)

    Analytical measurement of materials requires exact knowledge of their acid dissociation constant (pKa) values. In recent years, quantum mechanical calculations have been extensively used to study of acidities in the aqueous solutions and the results were compared with the experimental values. In this study, a theoretical ...

  8. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V

    1984-01-01

    Diffusion in Liquids: A Theoretical and Experimental Study aims to discuss the principles, applications, and advances in the field of diffusion, thermal diffusion, and thermal conduction in liquid systems. The book covers topics such as the principles of non-equilibrium thermodynamics; diffusion in binary and multicompetent systems; and experimental methods of studying diffusion processes in liquids. Also covered in the book are topics such as the theoretical interpretations of diffusion coefficients; hydrodynamic and kinetic theories; and diffusion in electrolyte systems. The text is recommen

  9. Theoretical atomic and molecular photophysics. Final technical report, October 1, 1981-September 30, 1982

    International Nuclear Information System (INIS)

    Nonlinearities arise in the interaction of light and matter as soon as the light intensity approaches the so-called saturation intensity. It is in this case that an atomic transition stops responding as a harmonic oscillator, and that the atom's inversion begins to play a role in the excitation process. Purely coherent intense plane-wave light gives rise to a variety of remarkable nonlinear effects upon absorption by, or transmission through, a collection of nearly resonant atoms or molecules. In many circumstances, one is interested in the excitation of atomic vapors under conditions that are far from purely coherent or plane-wave in character. Among the more realistic situations encountered in practice are those in which the light is a beam with finite cross section instead of a plane wave, and the atom-light interaction is made partially incoherent by the presence of noise, such as is contributed by collisions of various kinds. In addition, it may not be realistic to treat the absorbing atoms or molecules as if they had a well-defined unique ladder of energy levels through which an electron can be promoted en route to ionization. Few theoretical tools are available for analysis of nonlinear light-matter interactions in these more realistic situations. A brief summary is given here of research into propagation of intense light and dressed atom dynamics

  10. Theoretical studies of the spin-Hamiltonian parameters for the ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 70; Issue 4. Theoretical studies of the spin-Hamiltonian parameters for the orthorhombic Pr4+ centers in Sr2CeO4 ... Author Affiliations. Wen-Lin Feng1. Department of Applied Physics, Chongqing Institute of Technology, Chongqing 400050, People Republic of China ...

  11. A combined electrochemical and theoretical study of pyridine-based ...

    Indian Academy of Sciences (India)

    PARUL DOHARE

    2018-02-01

    Feb 1, 2018 ... mild steel (MS) in 1 M hydrochloric acid solution using electrochemical experiments and theoretical study. The results ... Quantum chemical calculations and Monte Carlo simulations were used to understand metal-inhibitor interaction and ...... steel in Bacil- lus sp. inoculated artificial seawater Corros. Sci.

  12. Generation, structure and reactivity of arynes: A theoretical study

    Indian Academy of Sciences (India)

    Generation, structure and reactivity of arynes: A theoretical study. PETER G S DKHAR and R H DUNCAN LYNGDOH*. Department of Chemistry, North-Eastern Hill University, Bijni Complex,. Shillong 793 003, India. MS received 20 September 1999; revised 14 February 2000. Abstract. The semiempirical AM1 SCF-MO ...

  13. Trends In The Study Of Language Variation:Theoretical And ...

    African Journals Online (AJOL)

    Register study, stylistics, sociolinguistics, discourse analysis, and English for specific purposes all deal with language variation. This can be gleaned from several perspectives. In this paper, however, we have tried to look at the issue of variation from two main perspectives namely: the theoretical and the taxonomic.

  14. Piezoelectricity in quasicrystals: A group-theoretical study

    Indian Academy of Sciences (India)

    Group-theoretical methods have been accepted as exact and reliable tools in studying the physical properties of crystals and quasicrystalline materials. By group representation theory, the maximum number of non-vanishing and independent second- order piezoelectric coefficients required by the seven pentagonal and ...

  15. Theoretical study of the mechanism of proton transfer in tautomeric ...

    Indian Academy of Sciences (India)

    Unknown

    Theoretical study of the mechanism of proton transfer in tautomeric systems: Alloxan. RITA KAKKAR*, BHUPENDRA K SARMA and VANDANA KATOCH. Department of Chemistry, University of Delhi, Delhi 110 007, India e-mail: rita_kakkar@vsnl.com. MS received 12 July 1999; revised 18 January 2000. Abstract.

  16. Theoretical study of catalytic hydrogenation of oxirane and its methyl ...

    African Journals Online (AJOL)

    C3H6O) is its methyl derivative. Theoretical studies on catalytic hydrogenation of both compounds, in presence of aluminium chloride (AlCl3) catalyst, are carried out. The products of reactions are ethanol and propan-1-ol from oxirane and ...

  17. A combined electrochemical and theoretical study of pyridine-based ...

    Indian Academy of Sciences (India)

    PARUL DOHARE

    2018-02-01

    Feb 1, 2018 ... mild steel (MS) in 1 M hydrochloric acid solution using electrochemical experiments and theoretical study. The results showed that all the three DAPs act as mixed type corrosion inhibitors, and are adsorbed on MS surface by following Langmuir adsorption isotherm. The methyl-substituted DAP-1 showed ...

  18. Theoretical study on mechanism, kinetics, and thermochemistry of ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 6. Theoretical study on mechanism, kinetics, and thermochemistry of the gas phase reaction of 2,2,2-trifluoroethyl butyrate with OH radicals at 298 K. Nand Kishor Gour Bhupesh Kumar Mishra Hari Ji Singh. Regular Articles Volume 127 Issue 6 June 2015 ...

  19. Theoretical study of the mechanism of proton transfer in tautomeric ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 4. Theoretical study of the mechanism of proton transfer in tautomeric systems: Alloxan ... The N-H bond is almost broken, while the O-H bond is only partially formed in the transition state. The other stabilizing effect in aqueous solution is due to bulk solvent ...

  20. Theoretical study of the mechanism of proton transfer in tautomeric ...

    Indian Academy of Sciences (India)

    Theoretical study of the mechanism of proton transfer in tautomeric systems: Alloxan ... reason is the almost complete separation of the two entities, i.e. the alloxan anion and the hydronium ion in the latter case, indicating that in this case a dissociative mechanism of the kind encountered in acid-base equilibria is operating.

  1. Theoretical study and numerical simulation of secondary flow in channels

    Energy Technology Data Exchange (ETDEWEB)

    Fort, J.; Halama, J.; Hrusova, M.; Kozel, K. [Technical Univ. Prague (Czech Republic). Dept. of Technical Mathematics; Skvor, M. [Ceska Akademie Ved, Prague (Czech Republic). Inst. of Thermomechanics

    1999-12-01

    Presented work deals with flow in a 3D curved channel of constant curvature and constant rectangular cross-section. Properties of typical secondary flow structures are theoretically studied. Some cases of subsonic flow were simulated numerically by two different finite volume methods. Numerical results are compared with experimental data. (orig.)

  2. Theoretical study and numerical simulation of secondary flow in channels

    Energy Technology Data Exchange (ETDEWEB)

    Fort, J.; Halama, J.; Hrusova, M.; Kozel, K. (Technical Univ. Prague (Czech Republic). Dept. of Technical Mathematics); Skvor, M. (Ceska Akademie Ved, Prague (Czech Republic). Inst. of Thermomechanics)

    1999-01-01

    Presented work deals with flow in a 3D curved channel of constant curvature and constant rectangular cross-section. Properties of typical secondary flow structures are theoretically studied. Some cases of subsonic flow were simulated numerically by two different finite volume methods. Numerical results are compared with experimental data. (orig.)

  3. Experimental and theoretical studies on a novel helical architecture ...

    Indian Academy of Sciences (India)

    Sci. Vol. 128, No. 12, December 2016, pp. 1895–1904. c Indian Academy of Sciences. DOI 10.1007/s12039-016-1195-9. Experimental and theoretical studies on a novel helical architecture driven by hydrogen and halogen bonding interactions. QING ZHU LIUa, SHAN SHAN WANGa, TENG FEI WANGa, JIAN GUO LINa,∗.

  4. Synthesis, experimental and theoretical studies of two cocrystals in 1 ...

    Indian Academy of Sciences (India)

    Abstract. This paper reports synthesis, characterization and theoretical studies of two 1:1 stoichiometric ratio cocrystals of 4,4'-bithiazole-2,2'-diamine (DABTZ) with 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (bpo) and 1,3-bis(4-pyridyl)ethane (bpa). These cocrystal compounds have been prepared by slow evaporation method and ...

  5. Drug and Alcohol Studies (Volume 2: Theoretical Studies)

    OpenAIRE

    MacGregor, S; Thom, B

    2014-01-01

    VOLUME TWO: THEORETICAL PERSPECTIVES Excerpt from Drug, Set and Setting: The Basis for Controlled Intoxicant Use N. Zinberg Sociocultural Anthropology and Alcohol and Drug Research Geoffrey Hunt and Judith Barker Towards a Unified Theory Addiction Is a Brain Disease and It Matters Alan Leshner Drug Dependence A. Thomas McLellan et al A Chronic Mental Illness Alcohol Dependence Griffith Edwards and Milton Gross Provisional Description of a Clinical Syndrome Illicit Drugs and the Rise of Epidem...

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

    Science.gov (United States)

    2013-09-19

    photodissociation reactions of ketene, methylamine, formic acid , methyl ethyl ketone, acetone and NO3. For instance, for NO3, a totally unknown...to photodissociation reactions of ketene, methylamine, formic acid , methyl ethyl ketone, acetone and NO3. For instance, for NO3, a totally unknown...THEORETICAL STUDIES OF GAS PHASE ELEMENTARY AND CARBON NANOSTRUCTURE GROWTH REACTIONS KEIJI MOROKUMA EMORY UNIVERSITY 09/19/2013 Final Report

  7. Theoretical nuclear physics: Final report for period February 1, 1984 to January 31, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Rost, E.; Kunz, P.D.

    1987-01-23

    Nuclear theory at the University of Colorado emphasizes the study of nuclear structure through the use of nuclear reactions. Recent efforts have been focussed on the role of relativistic models in nucleon-nucleus scattering and reactions. Further work delves into the underlying bases of the reaction theory itself.

  8. Theoretical study of electron transport throughout some molecular structures

    Science.gov (United States)

    Abbas, Mohammed A. A.; Hanoon, Falah H.; Al-Badry, Lafy F.

    2017-11-01

    The present work is a theoretical study of the electronic properties of some molecular structures. The system that takes into account in the study is left lead-donor-molecule-acceptor-right lead. The molecule, such as (phenyl, biphenyl, triphenyl, naphthalene, anthracene, and phenanthrene), is threaded by magnetic flux. This work contains two parts. First is computing density of states of the molecular structures as a closed system by density functional theory (DFT). Second is calculating the transmission probability and electric current of such molecular structures as an open system by steady-state theoretical model. Furthermore, the most important effects, taking into consideration are quantum interference, magnetic flux, and interface structure. Our results show that the connection of the molecule to the two leads, the number of rings, the magnetic flux, and the geometrical structure of the molecule play an important role in determining the energy gap of molecular structures.

  9. A theoretical and experimental study of microshield circuits

    Science.gov (United States)

    Dib, Nihad I.; Drayton, Rhonda F.; Katehi, Linda P. B.

    1993-05-01

    The novel type of monolithic planar transmission line presently studied theoretically and experimentally operates without via-holes or ground-equalizing air bridges; it also radiates less than conventional coplanar waveguides and furnishes a wide range of impedances in virtue of its many design parameters. The space-domain integral equation method is used to analyze several discontinuities of the proposed line. It is shown that the proposed line discontinuities radiate less than the corresponding coplanar waveguide cases.

  10. Theoretical and Experimental Studies of Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Harold G [Indiana University; Kostelecky, V Alan [Indiana University; Musser, James A [Indiana University

    2013-07-29

    The elementary particle physics research program at Indiana University spans a broad range of the most interesting topics in this fundamental field, including important contributions to each of the frontiers identified in the recent report of HEPAP's Particle Physics Prioritization Panel: the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. Experimentally, we contribute to knowledge at the Energy Frontier through our work on the D0 and ATLAS collaborations. We work at the Intensity Frontier on the MINOS and NOvA experiments and participate in R&D for LBNE. We are also very active on the theoretical side of each of these areas with internationally recognized efforts in phenomenology both in and beyond the Standard Model and in lattice QCD. Finally, although not part of this grant, members of the Indiana University particle physics group have strong involvement in several astrophysics projects at the Cosmic Frontier. Our research efforts are divided into three task areas. The Task A group works on D0 and ATLAS; Task B is our theory group; and Task C contains our MINOS, NOvA, and LBNE (LArTPC) research. Each task includes contributions from faculty, senior scientists, postdocs, graduate and undergraduate students, engineers, technicians, and administrative personnel. This work was supported by DOE Grant DE-FG02-91ER40661. In the following, we describe progress made in the research of each task during the final period of the grant, from November 1, 2009 to April 30, 2013.

  11. Sociomateriality: a theoretical framework for studying distributed medical education.

    Science.gov (United States)

    MacLeod, Anna; Kits, Olga; Whelan, Emma; Fournier, Cathy; Wilson, Keith; Power, Gregory; Mann, Karen; Tummons, Jonathan; Brown, Peggy Alexiadis

    2015-11-01

    Distributed medical education (DME) is a type of distance learning in which students participate in medical education from diverse geographic locations using Web conferencing, videoconferencing, e-learning, and similar tools. DME is becoming increasingly widespread in North America and around the world.Although relatively new to medical education, distance learning has a long history in the broader field of education and a related body of literature that speaks to the importance of engaging in rigorous and theoretically informed studies of distance learning. The existing DME literature is helpful, but it has been largely descriptive and lacks a critical "lens"-that is, a theoretical perspective from which to rigorously conceptualize and interrogate DME's social (relationships, people) and material (technologies, tools) aspects.The authors describe DME and theories about distance learning and show that such theories focus on social, pedagogical, and cognitive considerations without adequately taking into account material factors. They address this gap by proposing sociomateriality as a theoretical framework allowing researchers and educators to study DME and (1) understand and consider previously obscured actors, infrastructure, and other factors that, on the surface, seem unrelated and even unimportant; (2) see clearly how the social and material components of learning are intertwined in fluid, messy, and often uncertain ways; and (3) perhaps think differently, even in ways that disrupt traditional approaches, as they explore DME. The authors conclude that DME brings with it substantial investments of social and material resources, and therefore needs careful study, using approaches that embrace its complexity.

  12. Experimental and theoretical study on the electrospinning nanoporous fibers process

    International Nuclear Information System (INIS)

    Zhao, Jianghui; Si, Na; Xu, Lan; Tang, Xiaopeng; Song, Yanhua; Sun, Zhaoyang

    2016-01-01

    Porous materials can be prepared by sol–gel method, hydrothermal synthesis method, electrospinning and other methods. In this paper, electrospun porous nanofibers were prepared by adjusting electrospinning parameters. And the properties of obtained porous nanofiber mats were investigated. Theoretical analysis and experiment research were carried out to research mechanical mechanism of electrospun porous nanofibers, and could be used to optimize and control the porous structure. The theoretical analysis results were further verified according to the experimental data. In addition, Bernoulli equation was used to study the electrospinning “splaying” process. We found the ratio of pore width to pore length was varied along with the variation of the internal pressure of the jet, and the internal pressure of the jet increases with the velocity of the charged jet decreases. - Highlights: • Mechanical mechanism of electrospun porous nanofibers process was studied. • A simplifying gas–liquid two-phase flow model was established. • Bernoulli equation was used to study the electrospinning “splaying” process. • The theoretical results were in good agreement with the experimental data. • The electrospinning parameters affected the surface morphology of charged jet.

  13. THEORETICAL AND EXPERIMENTAL STUDY OF STRUCTURES SUBJECTED TO EARTHQUAKES

    Energy Technology Data Exchange (ETDEWEB)

    Soubirou, A.

    1967-12-31

    The object of the study was the investigation of the behaviour of structures subject to earthquakes. After .describing and analysing seismic movements, useful concepts for earthquake-proofing structures are lintroduced. Then, the dynamic behaviour of systems with n degrees of freedom was studied in order to evolve the theoretical computation of seismic behaviour, a typical application being reticulated structures. The next stage was showing the computational procedure for seismic spectra and the natural frequencies of buildings, an attempt being made to define earthquake-proofing criteria for a special type of reinforced-concrete construction. . The last matter dealt with is elastoplastic behaviour of structures, a study of increasingly growing importance.

  14. Theoretical studies of reactions at transition metal centers

    International Nuclear Information System (INIS)

    Rappe, A.K.; Goddard, W.A. III

    1981-01-01

    The considerations discussed for ab initio theoretical studies are the type of basis set and the levels of electron correlation or lack of correlation. The prototype systems described are C1 2 M=X, where M = Ti, Cr, and Mo, and X = CH 2 , NH, and O. These studies are utilized in examining metathesis by high-oxidation-state Cr and Mo complexes. Metathesis of olefins by the Cr complexes is unfavorable because of a competing reaction involving cyclopropane elimination. Metathesis by Mo complexes is more favorable, and it is concluded that the active catalyst is an oxo-carbene complex

  15. Theoretical study of magnetoelectric effects in noncentrosymmetric and cuprate superconductors

    Science.gov (United States)

    Kashyap, Manoj K.

    A century after the discovery of superconductivity at the lab of Kamerlingh Onnes in 1911, it is noticeable that the phenomenon is quite ubiquitous in nature. In addition to a long list of superconducting alloys and compounds, almost half the elements in the periodic table superconduct. By the late seventies, superconductivity was thought to be well understood. This turned out to be a myth, with the discovery of unconventional superconductors that defied Bardeen-Cooper-Schrieffer (BCS) theory. Cuprates have been the most prominent example among them ever since their discovery in 1986 by Bednorz and Muller. Another example of non-compliance with BCS theory lie among noncentrosymmetric superconductors. In this dissertation, magnetoelectric (ME) effects in these two classes of superconductors have been studied from different perspectives, utilizing Ginzburg-Landau (GL) theory. Even though GL theory was proposed before the BCS theory, it was not given much importance due to its phenomenological nature until Gor'kov proved that it is a limiting form of the microscopic BCS theory. However today, in the absence of any complete microscopic theory to explain superconductivity in unconventional superconductors, Ginzburg-Landau theory is an important tool to move ahead and qualitatively understand the behavior of varied superconducting systems. Noncentrosymmetric superconductors have generated much theoretical interest since 2004 despite been known for long. The absence of inversion symmetry in non- centrosymmetric superconductors allows for extra terms called Lifshitz invariants in the Ginzburg-Landau functional. This leads to magnetoelectric effects that do not exist in centrosymmetric superconductors. One manifestation of this is in the vortex structure in materials with a cubic point group O. In particular, a current is predicted to flow parallel to the applied magnetic field in such a vortex in addition to the usual vortex supercurrents. In this work, we present both

  16. A theoretical study for RTE-based parameter identification problems

    International Nuclear Information System (INIS)

    Tang, Jinping; Han, Bo; Han, Weimin

    2013-01-01

    This paper provides a theoretical study of reconstructing absorption and scattering coefficients based on the radiative transport equation (RTE) by using the total variation regularization method. The function space for solutions of the RTE is a natural one from the form of the boundary value problem of the RTE. We analyze the continuity and differentiability of the forward operator. We then show that the total variation regularization method can be applied for a stable solution. Convergence of the total variation-minimizing solution in the sense of the Bregman distance is also obtained. (paper)

  17. Theoretical study on perylene derivatives as fluorescent sensors for amines

    Science.gov (United States)

    Lathiotakis, Nektarios N.; Kerkines, Ioannis S. K.; Theodorakopoulos, Giannoula; Petsalakis, Ioannis D.

    2018-01-01

    A theoretical study is presented on perylene diimide (PDI) and perylene monoimide (PMI) and their action as sensors of amines in solution. Density functional theory (DFT) and Time dependent DFT (TDDFT) calculations are carried out on complexes of PDI and PMI with aniline in THF solution. The optimized geometries for the complexes have aniline lying parallel above the perylene at 3.15 Å and with binding energy of 0.53 eV in the ground state. The results on the excited states are consistent with a photoinduced electron transfer (PET) mechanism. The effective aniline-perylene distance resulting from a Mulliken's approach is 3.61 Å.

  18. Iron Complexes of Peptide Conjugates: Theoretical and Spectroscopic Study

    Czech Academy of Sciences Publication Activity Database

    Šebestík, Jaroslav; Šafařík, Martin; Bouř, Petr

    2011-01-01

    Roč. 96, č. 4 (2011), s. 506-506 ISSN 1097-0282. [ American Peptide Symposium /22./. 25.06.2011-30.06.2011, San Diego] R&D Projects: GA ČR GA203/07/1517; GA MŠk(CZ) LH11033; GA ČR GAP208/11/0105 Grant - others:AV ČR(CZ) M200550902 Institutional research plan: CEZ:AV0Z40550506 Keywords : deferipron * ferric complexes * Raman spectra * DFT study * peptide Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Theoretical studies of the electronic structure of small metal clusters

    Science.gov (United States)

    Jordan, K. D.

    1982-01-01

    Theoretical studies of the electronic structure of metal clusters, in particular clusters of Group IIA and IIB atoms were conducted. Early in the project it became clear that electron correlation involving d orbitals plays a more important role in the binding of these clusters than had been previously anticipated. This necessitated that computer codes for calculating two electron integrals and for constructing the resulting CI Hamiltonions be replaced with newer, more efficient procedures. Program modification, interfacing and testing were performed. Results of both plans are reported.

  20. Theoretical Study of the Diastereofacial Isomers of Aldrin and Dieldrin

    Directory of Open Access Journals (Sweden)

    Zoran Zdravkovski

    2006-02-01

    Full Text Available The Diels-Alder reaction of hexachlorocyclopentadiene with norbornadiene givesaldrin but theoretically three other diastereofacial isomers are possible. On oxidation theseisomers can generate eight adducts one of which is known as dieldrin. All these, as well asthe corresponding reactions with hexafluorocyclopenadiene were studied by semiempirical(AM1 and PM3 and hybrid density functional (B3LYP methods. Besides the energy levels,the transition states were calculated for the reactions leading to the diastereofacial isomers ofaldrin, which indicate that aldrin is the favored product of the reaction both fromthermodynamic and kinetic point of view.

  1. Theoretical studies of parallel current in the presence of fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, M. [Nihon Univ., College of Industrial Technology, Narashino, Chiba (Japan); Shiinab, S. [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Aizawa, M.; Osanai, Y. [Nihon University, Institute of Quantum Science, College of Science and Technology, Tokyo (Japan)

    2004-07-01

    Effects of electrostatic fluctuations on the current parallel to the magnetic field theoretically studied for magnetically confined plasmas. Based upon a closed set of equations for the ensemble-averaged distribution function and the response function to an infinitesimal external perturbation, a radial diffusion equation for the bootstrap and ohmic current densities is derived. The anomalous radial diffusion due to fluctuations as well as the finite-banana width effect is shown to significantly modify the conventional bootstrap current near the magnetic axis. It is also shown that this modification leads to the possibility of the completely bootstrapped tokamak. (authors)

  2. Generation of pulsed Bessel-Gauss beams using passive axicon-theoretical and experimental studies.

    Science.gov (United States)

    Parsa, Shahrzad; Fallah, Hamid Reza; Ramezani, Mohsen; Soltanolkotabi, Mahmood

    2012-10-20

    We studied the conditions for generating passive Bessel-Gauss beams by using an axicon. We designed an appropriate Gaussian resonator and extracted a quasi-fundamental Gaussian mode from a pulsed Nd:YAG laser pumped by a Xenon flash lamp and measured its parameters, such as propagation factor, divergence angle, and Rayleigh range. Then we generated passive Bessel-Gauss beams using an axicon and investigated their propagation properties, theoretically and experimentally. For example, for the axicon of 1°, the output energy and the Rayleigh range of the generated Bessel-Gauss beams were measured to be 58 mJ and 229.3 mm, respectively. We compared these properties with our results of the Gaussian mode. Finally, by using axicons with different apex angles, and also by changing the beam spot size on the axicon, we generated Bessel-Gauss beams and studied their properties theoretically and experimentally.

  3. A Combined Theoretical and Experimental Study for Silver Electroplating

    Science.gov (United States)

    Liu, Anmin; Ren, Xuefeng; An, Maozhong; Zhang, Jinqiu; Yang, Peixia; Wang, Bo; Zhu, Yongming; Wang, Chong

    2014-01-01

    A novel method combined theoretical and experimental study for environmental friendly silver electroplating was introduced. Quantum chemical calculations and molecular dynamic (MD) simulations were employed for predicting the behaviour and function of the complexing agents. Electronic properties, orbital information, and single point energies of the 5,5-dimethylhydantoin (DMH), nicotinic acid (NA), as well as their silver(I)-complexes were provided by quantum chemical calculations based on density functional theory (DFT). Adsorption behaviors of the agents on copper and silver surfaces were investigated using MD simulations. Basing on the data of quantum chemical calculations and MD simulations, we believed that DMH and NA could be the promising complexing agents for silver electroplating. The experimental results, including of electrochemical measurement and silver electroplating, further confirmed the above prediction. This efficient and versatile method thus opens a new window to study or design complexing agents for generalized metal electroplating and will vigorously promote the level of this research region.

  4. Theoretical provisions for the discharge at TJ-1 (Preliminary study)

    International Nuclear Information System (INIS)

    Guasp, J.

    1981-01-01

    Using the transport code PLASMATOR a numerical study about the TJ-1 discharge (a Tokamak close to be installed at JEN) has been made, observing the behaviour under huge variations on the transport coefficients as well as on density and current. Noteworthy a scaling law of the kind τ E ∼n θ has been contested at not too high density, The model insensibility upon the initial values has been confirmed and the effects of variations on the recycling coefficient and the rate rise of current studied too. Finally comparisons with alternative models have been accomplished. (Author) 29 refs

  5. Theoretical study of asymmetric super-rotors: Alignment and orientation

    Science.gov (United States)

    Omiste, Juan J.

    2018-02-01

    We report a theoretical study of the optical centrifuge acceleration of an asymmetric top molecule interacting with an electric static field by solving the time-dependent Schrödinger equation in the rigid rotor approximation. A detailed analysis of the mixing of the angular momentum in both the molecular and the laboratory fixed frames allows us to deepen the understanding of the main features of the acceleration process, for instance, the effective angular frequency of the molecule at the end of the pulse. For the case of the SO2 molecular super-rotor, we show numerically that it rotates around one internal axis and that its dynamics is confined to the plane defined by the polarization axis of the laser, in agreement with experimental findings. Furthermore, we consider the orientation patterns induced by the dc field, showing the characteristics of their structure as a function of the strength of the static field and the initial configuration of the fields.

  6. Theoretical Study of Irradiation Effects in Close Binaries

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao, M.

    2009-06-01

    Full Text Available The effect of irradiation is studied in a close binary systemassuming that the secondary component is a point source, moving in a circularorbit. The irradiation effects are calculatedon the atmosphere of the primary component in a 3-dimensional Cartesiancoordinate geometry. In treating the reflection effect theoretically, the totalradiation $(S_mathrm{T}$ is obtained as the sum of the radiation of 1 the effect ofirradiation on the primary component which is calculated by using onedimensional rod model $(S_mathrm{r}$ and 2 the self radiation of the primarycomponent which is calculated by using the solution of radiative transferequation in spherical symmetry $(S_mathrm{s}$. The radiation field is estimated alongthe line of sight of the observer at infinity. It is shown how the radiationfield changes depending on the position of the secondary component.

  7. Electrochemistry of chlorogenic acid: experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Namazian, Mansoor [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)]. E-mail: namazian@yazduni.ac.ir; Zare, Hamid R. [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

    2005-08-10

    Cyclic voltammetry, chronoamperometry and rotating disk electrode voltammetry as well as quantum chemical methods, are used for electrochemical study of chlorogenic acid, as an important biological molecule. The standard formal potential, diffusion coefficient, and heterogeneous electron transfer rate constant of chlorogenic acid in aqueous solution are investigated. Acidic dissociation constant of chlorogenic acid is also obtained. Quantum mechanical calculations on oxidation of chlorogenic acid in aqueous solution, using density functional theory are presented. The change of Gibbs free energy and entropy of oxidation of chlorogenic acid are calculated using thermochemistry calculations. The calculations in aqueous solution are carried out with the use of polarizable continuum solvation method. Theoretical standard electrode potential of chlorogenic acid is achieved to be 0.580 V versus standard calomel electrode (SCE) which is in agreement with the experimental value of 0.617 V obtained experimentally in this work. The difference is consistent with the values we previously reported for other quinone derivatives.

  8. Theoretical and Experimental Study of Plasmonic Polymer Solar Cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Adam, Jost; Madsen, Morten

    The organic bulk hetero-junction solar cell has remarkable advantages such as low cost, mechanical flexibility and simple process techniques. Recently, low-band gap photoactive materials have obtained a significant attention due to their potential to absorb a wider range of the solar spectrum...... to attain higher power conversion efficiencies. Many low-band gap photoactive materials, however, still show a relatively low external quantum efficiency of less than 60% [1]. One possible approach to improve the device performance is to increase the light absorption in the active layer. This may, amongst...... other approaches, be achieved by using nano- or micro-structures that trap light at specific wavelengths [2], or by using the localized surface plasmon resonance effect of metal nanoparticles in the devices. In this work, we theoretically studied planar polymer solar cell based on finite-difference time...

  9. Experimental and theoretical studies of buoyant-thermo capillary flow

    International Nuclear Information System (INIS)

    Favre, E.; Blumenfeld, L.; Soubbaramayer

    1996-01-01

    In the AVLIS process, uranium metal is evaporated using a high power electron gun. We have prior discussed the power balance equation in the electron beam evaporation process and pointed out, among the loss terms, the importance of the power loss due to the convective flow in the molten pool driven by buoyancy and thermo capillarity. An empirical formula has been derived from model experiments with cerium, to estimate the latter power loss and that formula can be used practically in engineering calculations. In order to complete the empirical approach, a more fundamental research program of theoretical and experimental studies have been carried out in Cea-France, with the objective of understanding the basic phenomena (heat transport, flow instabilities, turbulence, etc.) occurring in a convective flow in a liquid layer locally heated on its free surface

  10. A theoretical study on critical phenomena of magnetic soft modes

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiaoyan [Department of Mathematics, Shanghai University, 99 Shangda Road, 200444 Shanghai (China); Yang, Guohong [Department of Physics, Shanghai University, 99 Shangda Road, 200444 Shanghai (China); Shanghai Key Lab for Astrophysics, 100 Guilin Road, 200234 Shanghai (China); Yan, Ming, E-mail: myan@shu.edu.cn [Department of Physics, Shanghai University, 99 Shangda Road, 200444 Shanghai (China)

    2017-02-01

    Below a threshold magnetic field, domain structures in ferromagnetic samples may start to nucleate from the initially saturated state via either continuous or discontinuous phase transitions. Such processes are usually accompanied by the occurrence of soft spin-wave modes at the critical point. In this paper, we present a theoretical study on the critical phenomena of uniform soft modes in a macrospin model and spatially non-uniform ones in ferromagnetic thin films. The critical exponents of the mode frequency and its polarization are derived. The value is found to be equal to one half, which is directly related to the breaking of a reflection-symmetry in the phase transition. At the critical point, the soft mode becomes linearly polarized, which provides an additional measurable effect of the critical phenomena.

  11. Theoretical study of diaquamalonatozinc (II) single crystal for ...

    Indian Academy of Sciences (India)

    The aim of the present paper is to employ theoretical methods to investigate the zero field splitting (ZFS) parameter and to investigate the position of the dopant in the host. These theoretical calculations have been compared with the empirical results. The superposition model (SPM)with themicroscopic spin-Hamiltonian ...

  12. Additional EIPC Study Analysis. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, Stanton W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gotham, Douglas J. [Purdue Univ., West Lafayette, IN (United States); Luciani, Ralph L. [Navigant Consultant Inc., Suwanee, GA (United States)

    2014-12-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

  13. Automated diagnostics scoping study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Quadrel, R.W.; Lash, T.A.

    1994-06-01

    The objective of the Automated Diagnostics Scoping Study was to investigate the needs for diagnostics in building operation and to examine some of the current technologies in automated diagnostics that can address these needs. The study was conducted in two parts. In the needs analysis, the authors interviewed facility managers and engineers at five building sites. In the technology survey, they collected published information on automated diagnostic technologies in commercial and military applications as well as on technologies currently under research. The following describe key areas that the authors identify for the research, development, and deployment of automated diagnostic technologies: tools and techniques to aid diagnosis during building commissioning, especially those that address issues arising from integrating building systems and diagnosing multiple simultaneous faults; technologies to aid diagnosis for systems and components that are unmonitored or unalarmed; automated capabilities to assist cause-and-effect exploration during diagnosis; inexpensive, reliable sensors, especially those that expand the current range of sensory input; technologies that aid predictive diagnosis through trend analysis; integration of simulation and optimization tools with building automation systems to optimize control strategies and energy performance; integration of diagnostic, control, and preventive maintenance technologies. By relating existing technologies to perceived and actual needs, the authors reached some conclusions about the opportunities for automated diagnostics in building operation. Some of a building operator`s needs can be satisfied by off-the-shelf hardware and software. Other needs are not so easily satisfied, suggesting directions for future research. Their conclusions and suggestions are offered in the final section of this study.

  14. Theoretical Studies of Oxygen Reduction and Proton Transfer in SOFCs and Nerve Agents on Selected Surfaces

    Science.gov (United States)

    2015-11-19

    ABOVE ADDRESS. Benedict College Office of Research 1600 Harden St. Columbia, SC 29204 -1058 30-Jun-2015 ABSTRACT Final Report: Theoretical Studies of...graduated during this period: 1.00 0.00 1.00 0.00 0.00 0.00 1.00 Kahla Haines, 2nd place, Benedict College Summer research institute Changyong Qin...Distinguished Faculty of Benedict College 2013 Changyong Qin, Excellence in Teaching Award by SCICU 2014 The number of undergraduates funded by this

  15. Pipeline bottoming cycle study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  16. Experimental and Theoretical Study of Microwave-Active Materials

    National Research Council Canada - National Science Library

    Mei, Wai-Ning

    2001-01-01

    .... The results to date indicate the SCAD method produces accurate physical parameters. They are also using thin-film techniques to fabricate metastable materials predicted by the theoretical calculations to have useful or interesting properties.

  17. Theoretical study on absorption and emission spectra of adenine analogues.

    Science.gov (United States)

    Liu, Hongxia; Song, Qixia; Yang, Yan; Li, Yan; Wang, Haijun

    2014-04-01

    Fluorescent nucleoside analogues have attracted much attention in studying the structure and dynamics of nucleic acids in recent years. In the present work, we use theoretical calculations to investigate the structural and optical properties of four adenine analogues (termed as A1, A2, A3, and A4), and also consider the effects of aqueous solution and base pairing. The results show that the fluorescent adenine analogues can pair with thymine to form stable H-bonded WC base pairs. The excited geometries of both adenine analogues and WC base pairs are similar to the ground geometries. The absorption and emission maxima of adenine analogues are greatly red shifted compared with nature adenine, the oscillator strengths of A1 and A2 are stronger than A3 and A4 in both absorption and emission spectra. The calculated low-energy peaks in the absorption spectra are in good agreement with the experimental data. In general, the aqueous solution and base pairing can slightly red-shift both the absorption and emission maxima, and can increase the oscillator strengths of absorption spectra, but significantly decrease the oscillator strengths of A3 in emission spectra.

  18. A theoretical and spectroscopic study of conformational structures of piroxicam

    Science.gov (United States)

    Souza, Kely Ferreira de; Martins, José A.; Pessine, Francisco B. T.; Custodio, Rogério

    2010-02-01

    Piroxicam (PRX) has been widely studied in an attempt to elucidate the causes and mechanisms of its side effects, mainly the photo-toxicity. In this paper fluorescence spectra in non-protic solvents and different polarities were carried out along with theoretical calculations. Preliminary potential surfaces of the keto and enol forms were obtained at AM1 level of theory providing the most stable conformers, which had their structure re-optimized through the B3LYP/CEP-31G(d,p) method. From the optimized structures, the electronic spectra were calculated using the TD-DFT method in vacuum and including the solvent effect through the PCM method and a single water molecule near PRX. A new potential surface was constructed to the enol tautomer at DFT level and the most stable conformers were submitted to the QST2 calculations. The experimental data showed that in apolar media, the solution fluorescence is raised. Based on conformational analysis for the two tautomers, keto and enol, the results indicated that the PRX-enol is the main tautomer related to the drug fluorescence, which is reinforced by the spectra results, as well as the interconvertion barrier obtained from the QST2 calculations. The results suggest that the PRX one of the enol conformers presents great possibility of involvement in the photo-toxicity mechanisms.

  19. Experimental and theoretical study of Co sorption in clay montmorillonites

    Science.gov (United States)

    Gil Rebaza, A. V.; Montes, M. L.; Taylor, M. A.; Errico, L. A.; Alonso, R. E.

    2018-03-01

    Montmorillonite (MMT) clays are 2:1 layered structures which in natural state may allocate different hydrated cations such as M-nH2O (M = Na, Ca, Fe, etc) in its interlayer space. Depending on the capability for ion sorption, these materials are interesting for environmental remediation. In this work we experimentally study the Co sorption in a natural Na-MMT using UV-visible spectrometry and XRD on semi-oriented samples, and then analyze the sorption ability of this clay by means of ab initio calculation performed on pristine MMT. The structural properties of Na-MMT and Co-adsorbed MMT, and the hyperfine parameters at different atomic sites were analyzed and compared with the experimental ones for the first, and for the case of the hyperfine parameters, presented for the first time for the last. The theoretical predictions based on total energy considerations confirm that Co incorporation replacing Na is energetically favorable. Also, the basal spacing d001 experimentally obtained is well reproduced.

  20. Theoretical studies of potential energy surfaces and computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, R. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This project involves the development, implementation, and application of theoretical methods for the calculation and characterization of potential energy surfaces involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. This difficult challenge is met with general multiconfiguration self-consistent-field (MCSCF) and multireference single- and double-excitation configuration interaction (MRSDCI) methods. In contrast to the more common single-reference electronic structure methods, this approach is capable of describing accurately molecular systems that are highly distorted away from their equilibrium geometries, including reactant, fragment, and transition-state geometries, and of describing regions of the potential surface that are associated with electronic wave functions of widely varying nature. The MCSCF reference wave functions are designed to be sufficiently flexible to describe qualitatively the changes in the electronic structure over the broad range of geometries of interest. The necessary mixing of ionic, covalent, and Rydberg contributions, along with the appropriate treatment of the different electron-spin components (e.g. closed shell, high-spin open-shell, low-spin open shell, radical, diradical, etc.) of the wave functions, are treated correctly at this level. Further treatment of electron correlation effects is included using large scale multireference CI wave functions, particularly including the single and double excitations relative to the MCSCF reference space. This leads to the most flexible and accurate large-scale MRSDCI wave functions that have been used to date in global PES studies.

  1. Optical activity in planar chiral metamaterials: Theoretical study

    International Nuclear Information System (INIS)

    Bai, Benfeng; Svirko, Yuri; Turunen, Jari; Vallius, Tuomas

    2007-01-01

    A thorough theoretical study of the optical activity in planar chiral metamaterial (PCM) structures, made of both dielectric and metallic media, is conducted by the analysis of gammadion-shaped nanoparticle arrays. The general polarization properties are first analyzed from an effective-medium perspective, by analogy with natural optical activity, and then verified by rigorous numerical simulation, some of which are corroborated by previous experimental results. The numerical analysis suggests that giant polarization rotation (tens of degrees) may be achieved in the PCM structures with a thickness of only hundreds of nanometers. The artificial optical activity arises from circular birefringence induced by the structural chirality and is enhanced by the guided-mode or surface-plasmon resonances taking place in the structures. There are two polarization conversion types in the dielectric PCMs, whereas only one type in the metallic ones. Many intriguing features of the polarization property of PCMs are also revealed and explained: the polarization effect is reciprocal and vanishes in the symmetrically layered structures; the effect occurs only in the transmitted field, but not in the reflected field; and the polarization spectra of two enantiomeric PCM structures are mirror symmetric to each other. These remarkable properties pave the way for the PCMs to be used as polarization elements in new-generation integrated optical systems

  2. Theoretical Studies Of Nucleation Kinetics And Nanodroplet Microstructure

    International Nuclear Information System (INIS)

    Wilemski, Gerald

    2009-01-01

    The goals of this project were to (1) explore ways of bridging the gap between fundamental molecular nucleation theories and phenomenological approaches based on thermodynamic reasoning, (2) test and improve binary nucleation theory, and (3) provide the theoretical underpinning for a powerful new experimental technique, small angle neutron scattering (SANS) from nanodroplet aerosols, that can probe the compositional structure of nanodroplets. This report summarizes the accomplishments of this project in realizing these goals. Publications supported by this project fall into three general categories: (1) theoretical work on nucleation theory (2) experiments and modeling of nucleation and condensation in supersonic nozzles, and (3) experimental and theoretical work on nanodroplet structure and neutron scattering. These publications are listed and briefly summarized in this report.

  3. Theoretical study on device efficiency of pulsed liquid jet pump

    International Nuclear Information System (INIS)

    Gao Chuanchang; Lu Hongqi; Wang Shicheng; Cheng Mingchuan

    2001-01-01

    The influence of the main factors on device efficiency of pulsed liquid jet pump with gas-liquid piston is analysed, the theoretical equation and its time-averaged solution of pulsed liquid jet pump device efficiency are derived. The theoretical and experimental results show that the efficiency of transmission of energy and mass to use pulsed jet is greatly raised, compared with steady jet, in the same device of liquid jet pump. The calculating results of time-averaged efficiency of pulsed liquid jet pump are approximately in agreement with the experimental results in our and foreign countries

  4. Studying stellar rotation and convection theoretical background and seismic diagnostics

    CERN Document Server

    Belkacem, Kévin; Neiner, Coralie; Lignières, Francois; Green, John

    2013-01-01

    This volume synthesizes the results of work carried out by several international teams of the SIROCO (Seismology for Rotation and Convection) collaboration. It provides the theoretical background required to interpret the huge quantity of high-quality observational data recently provided by space experiments such as CoRoT and Kepler. Asteroseismology allows astrophysicists to test, to model and to understand stellar structure and evolution as never before. The chapters in this book address the two groups of topics summarized as "Stellar Rotation and Associated Seismology" as well as "Stellar Convection and Associated Seismology". The book offers the reader solid theoretical background knowledge and adapted seismic diagnostic techniques.

  5. Medical waste irradiation study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Adler, R.J.; Stein, J. [North Star Research Corp., Albuquerque, NM (United States); Nygard, J. [Advance Bio-Control (United States)

    1998-07-25

    The North Star Research Corporation Medical Waste project is described in this report, with details of design, construction, operation, and results to date. The project began with preliminary design of the accelerator. The initial design was for a single accelerator chamber with a vacuum tube cavity driver built into the chamber itself, rather than using a commercial tube separate from the RF accelerator. The authors believed that this would provide more adjustability and permit better coupling to be obtained. They did not have sufficient success with that approach, and finally completed the project using a DC accelerator with a unique new scanning system to irradiate the waste.

  6. Medical waste irradiation study. Final report

    International Nuclear Information System (INIS)

    Adler, R.J.; Stein, J.; Nygard, J.

    1998-01-01

    The North Star Research Corporation Medical Waste project is described in this report, with details of design, construction, operation, and results to date. The project began with preliminary design of the accelerator. The initial design was for a single accelerator chamber with a vacuum tube cavity driver built into the chamber itself, rather than using a commercial tube separate from the RF accelerator. The authors believed that this would provide more adjustability and permit better coupling to be obtained. They did not have sufficient success with that approach, and finally completed the project using a DC accelerator with a unique new scanning system to irradiate the waste

  7. Theoretical and Experimental Study on Electromechanical Coupling Properties of Multihammer Synchronous Vibration System

    Directory of Open Access Journals (Sweden)

    Xin Lai

    2016-01-01

    Full Text Available Industrial simulation of real external load using multiple exciting points or increasing exciting force by synchronizing multiple exciting forces requires multiple vibration hammers to be coordinated and work together. Multihammer vibration system which consists of several hammers is a complex electromechanical system with complex electromechanical coupling. In this paper, electromechanical coupling properties of such a multihammer vibration system were studied in detail using theoretical derivation, numerical simulation, and experiment. A kinetic model of multihammer synchronous vibration system was established, and approximate expressions for electromechanical coupling strength were solved using a small parameter periodic averaging method. Basic coupling rules and reasons were obtained. Self-synchronization and frequency hopping phenomenon were also analyzed. Subsequently, numerical simulations were carried out and electromechanical coupling process was obtained for different parameters. Simulation results verify correctness of the proposed model and results. Finally, experiments were carried out, self-synchronization and frequency hopping phenomenon were both observed, and results agree well with theoretical deduction and simulation results. These results provide theoretical foundations for multihammer synchronous vibration system and its synchronous control.

  8. EXPERIMENTAL AND THEORETICAL NMR STUDY OF 4-(1 ...

    African Journals Online (AJOL)

    Preferred Customer

    increased to cover various kinds of compounds, including biological, inorganic and organometallic compounds [8]. 1D and 2D hetero- and homonuclear NMR methods enable to get full assignments and structural information of organic compounds [9-11]. For the theoretical NMR investigations, the gauge including atomic ...

  9. Theoretical studies of ethylnitrolic acid using Gaussian | Nikafshar ...

    African Journals Online (AJOL)

    The tautomerism of all possible forms of ethylnitrolic acid was investigated theoretically in various environment including gas phase, ethanol, dimethyl sulfoxide (DMSO) and water. The calculations were carried out at DFT/B3LYP and MP2 of theory singly. It was found that, form of B eythynitrolic acid is the most stable isomer ...

  10. Theoretical Studies of Small-System Thermodynamics in Energetic Materials

    Science.gov (United States)

    2016-01-06

    molecular explosives and interfaces between explosive constituent materials. Exploring how the fundamental thermodynamic properties and energy...SECURITY CLASSIFICATION OF: This is a comprehensive theoretical research program to investigate the fundamental principles of small-system thermodynamics ...a.k.a. nanothermodynamics). The proposed work is motivated by our desire to better understand the fundamental dynamics and thermodynamics of

  11. Theoretical Framework of the filmed Interview in Communication Studies

    Directory of Open Access Journals (Sweden)

    LEBTAHI Yannick

    2016-07-01

    Full Text Available In the Social Sciences today, there are a variety of ways to approach the various areas of investigation and a wide range of observational methods. Depending on academic background and research interests, researchers explore and emphasize certain approaches and categorizations at the expense of others in the implementation of their audiovisual investigations. These observations lead us to first question the definition of image in its connection to the object of research and its status and, secondly, to identify the diversity of current practices and uses. Indeed, the status of an image changes according to the media used and the contexts of reception. The circulation of images promotes exchange and connection between the various groups of actors. If we awkwardly accompany images, we risk unwittingly betraying their original meaning. Furthermore, there is the possibility of conflicts or unintended distortions linked to the activities of projection and identification. Our goal will be to propose a methodological framework and establish an initial model for all researchers in Communication Studies using the audiovisual method. Finally, the researcher accepts not only to properly conduct his research, but also to present an audiovisual project taking into account from the start advantages, constraints, issues of influence and scientific impact.

  12. Crystal structure and theoretical studies on quinoline phosphate

    Science.gov (United States)

    Ben Issa, T.; Ghalla, H.; Marzougui, S.; Benhamada, L.

    2017-12-01

    The crystal structure of (C9H7N) H3PO4 (QP) was determined from single crystals obtained by slow evaporation methods (space group Pī; a = 7.5508(3) Å, b = 7.9705(3) Å, c = 8.6849(3) Å; α = 77.3725(18)°, β = 82.6225(19)°, γ = 74.9829(19)°). The crystal structure of QP is built up from infinite hydrogen bonding inorganic chains of (H3PO4)n lay parallel to the an axis, which are also connected to the quinoline rings through hydrogen bonds in a 3D arrangement. The structure was examined through atoms in molecules (AIM) topological and Hirshfeld surface (HS) analyses and its molecular structure optimized by theoretical density functional (DFT) calculations. The QP observed IR absorptions between 4000 and 400 cm-1 were assigned on the basis of the calculated theoretical vibrational modes.

  13. Spectroscopic Analysis of Neurotransmitters: A Theoretical and Experimental Raman Study

    Science.gov (United States)

    Alonzo, Matthew

    Surface-enhanced Raman spectroscopy (SERS) was applied to investigate the feasibility in the detection and monitoring of the dopamine (DA) neurotransmitter adsorbed onto silver nanoparticles (Ag NPs) at 10-11 molar, a concentration far below physiological levels. In addition, density functional theory (DFT) calculations were obtained with the Gaussian-09 analytical suite software to generate the theoretical molecular configuration of DA in its neutral, cationic, anionic, and dopaminequinone states for the conversion of computer-simulated Raman spectra. Comparison of theoretical and experimental results show good agreement and imply the presence of dopamine in all of its molecular forms in the experimental setting. The dominant dopamine Raman bands at 750 cm-1 and 795 cm-1 suggest the adsorption of dopaminequinone onto the silver nanoparticle surface. The results of this experiment give good insight into the applicability of using Raman spectroscopy for the biodetection of neurotransmitters.

  14. Rovibrational and temperature effects in theoretical studies of NMR parameters

    DEFF Research Database (Denmark)

    Faber, Rasmus; Kaminsky, Jakub; Sauer, Stephan P. A.

    2016-01-01

    The demand for high precision calculations of NMR shieldings (or their related values, chemical shifts δ) and spin-spin coupling constants facilitating and supporting detailed interpretations of NMR spectra increases hand in hand with the development of computational techniques and hardware...... resources. Highly sophisticated calculations including even relativistic effects are nowadays possible for these properties. However, NMR parameters depend not only on molecular structure and environment but also on molecular flexibility and temperature and the apparent success of theoretical predictions...

  15. Theoretical studies in weak, electromagnetic and strong interactions. Attachments

    International Nuclear Information System (INIS)

    Nandi, S.

    1999-01-01

    The project covered a wide area of current research in theoretical high-energy physics. This included Standard Model (SM) as well as physics beyond the Standard Model. Specific topics included supersymmetry (SUSY), perturbative quantum chromodynamics (QCD), a new weak interaction for the third family (called topflavor), neutrino masses and mixings, topcolor model, Pade approximation, and its application to perturbative QCD and other physical processes

  16. Theoretical studies of lipid bilayer electroporation using molecular dynamics simulations

    Science.gov (United States)

    Levine, Zachary Alan

    system where lipids can become damaged or severely impacted from interacting with reactive oxygen species, and these events become more frequent with age. The results are then compared to experiments where we show agreement between our simulations, theoretical models, and experiments with peroxidized cells in our lab. In Chapter 3 I outline a set of unique metrics which can be used to quantitatively measure the life cycle of a discrete electropore for the first time, across multiple lipid species, and I compare these results to analytical models where we find good agreement with theory. In Chapter 4 I use the life cycle of an electropore as a tool to measure the effects of electrolyte and lipid headgroup charge on electroporation compared to electrolyte-free and zwitterionic systems, in addition to presenting ion binding isotherms to determine the validity of our simulated electrolyte models. Chapters 5 and 6 focus on the roles of water and lipid respectively on electroporation using simplified water:vacuum systems, osmotic swelling simulations, systems at varying temperature, and systems where we successfully modulated the electropore radius using customized time-dependent electric fields. I conclude this dissertation with a brief summary of these studies followed by a short outlook on the future of electroporation simulations as a whole.

  17. Canister displacement in KBS-3V. A theoretical study

    International Nuclear Information System (INIS)

    Boergesson, Lennart; Hernelind, Jan

    2006-02-01

    The vertical displacement of the canister in the KBS-3V concept has been studied in a number of consolidation and creep calculations using the FE-program ABAQUS. The creep model used for the calculations is based on Singh-Mitchell's creep theory, which has been adapted to and verified for the buffer material MX-80 in earlier tests. A porous elastic model with Drucker-Prager plasticity has been used for the consolidation calculations. For simplicity the buffer has been assumed to be water saturated from start. In one set of calculations only the consolidation and creep in the buffer without considering the interaction with the backfill was studied. In the other set of calculations the interaction with the backfill was included for a backfill consisting of an in situ compacted mixture of 30% bentonite and 70% crushed rock. The motivation to also study the behaviour of the buffer alone was that the final choice of backfill material and backfilling technique is not made yet so that set of calculations simulates a backfill that has identical properties with the buffer. The two cases represent two extreme cases, one with a backfill that has a low stiffness and the lowest allowable swelling pressure and one that has the highest possible swelling pressure and stiffness. The base cases in the calculations correspond to the final average density at saturation of 2,000 kg/m 3 with the expected swelling pressure of 7 MPa in a buffer. In order to study the sensitivity of the system to loss in bentonite mass and swelling pressure seven additional calculations were done with reduced swelling pressure down to 80 kPa corresponding to a density at water saturation of about 1,500 kg/m 3 . The calculations included two stages, where the first stage models the swelling and consolidation that takes place in order for the buffer to reach force equilibrium. This stage takes place during the saturation phase and the subsequent consolidation/swelling phase. The second stage models the

  18. Swinging Atwood Machine: Experimental and numerical results, and a theoretical study

    Science.gov (United States)

    Pujol, O.; Pérez, J. P.; Ramis, J. P.; Simó, C.; Simon, S.; Weil, J. A.

    2010-06-01

    A Swinging Atwood Machine ( SAM) is built and some experimental results concerning its dynamic behaviour are presented. Experiments clearly show that pulleys play a role in the motion of the pendulum, since they can rotate and have non-negligible radii and masses. Equations of motion must therefore take into account the moment of inertia of the pulleys, as well as the winding of the rope around them. Their influence is compared to previous studies. A preliminary discussion of the role of dissipation is included. The theoretical behaviour of the system with pulleys is illustrated numerically, and the relevance of different parameters is highlighted. Finally, the integrability of the dynamic system is studied, the main result being that the machine with pulleys is non-integrable. The status of the results on integrability of the pulley-less machine is also recalled.

  19. Theoretical studies of permeability inversion from seismoelectric logs

    Science.gov (United States)

    Hu, H.; Guan, W.; Zhao, W.

    2012-04-01

    Permeability is one of the most important parameters for evaluating the level of difficulty in oil and gas exploitation. A quick, continuous and accurate in-situ estimate of reservoir permeability is highly significant. Stoneley wave logs have been used to determine formation permeability (Tang and Cheng, 1996). However, the inversion errors of this method are too big in low-permeability formations, especially in high-porosity and low-permeability formations resulting from the high clay content in pores. In this study, we propose to invert permeability by using the full waveforms of seismoelectric logs with low frequencies. This method is based on the relationship of permeability with the ratio of the electric excitation intensity to the pressure field's (REP) with respect to the Stoneley wave in seismoelectric logs. By solving the governing equations for electrokinetic coupled wavefields in homogeneous fluid-saturated porous media (Pride, 1994), we calculate the full waveforms of the borehole seismoelectric wavefields excited by a point pressure source and investigate frequency-dependent excitation intensities of the mode waves and excitation intensities of the real branch points in seismoelectric logs. It is found that the REP's phase, which reflects the phase discrepancy between the Stoneley-wave-induced electric field and the acoustic pressure, is sensitive to formation permeability. To check the relation between permeability and REP's phase qualitatively, an approximate expression of the tangent of the REP's argument is derived theoretically as tan(θEP) ≈-ωc/ω = -φη/ (2πfα ∞ρfκ0), where θEPdenotes the arguments of the REP and their principal value is the REP's phase,ω is the angular frequency,ωc is a critical angular frequency that separates the low-frequency viscous flow from the high-frequency inertial flow, φ is the porosity, α∞ is the tortuosity, κ0 is the Darcy permeability, ρf and η are the density and the viscosity of the pore

  20. Theoretical and experimental study of actinide complexes with monoamides and organophosphorus ligands in solution

    International Nuclear Information System (INIS)

    Ribokaite, Kristina

    2013-01-01

    Monoamides and organophosphate are of great interest for the nuclear fuel cycle. Such ligands can selectively extract actinides in liquid-liquid extraction processes. The structure of the extractant (its functional group and its alkyl substituents) has a predominant role in the selective separation of actinides. This thesis concerns the theoretical and experimental studies of model systems in the aim of better understanding of the effect on molecular structures of the complexes. Structures of actinides complexes formed with model ligands in simple media (water or methanol in the presence of nitrate ions) have been characterized. At first, the complexation of uranyl by monoamide and phosphine oxide was studied in water and methanol. Molecular Dynamics simulations and DFT calculations were used to quantify the stability of uranyl complexes with those ligands, and to determine their structural properties. The theoretical results were then compared with experimental results obtained by UV-visible, infrared, Raman and EXAFS on the same chemical systems. The results were used to highlight the greater stability of uranyl complexes with phosphine oxide and monoamides. Further spectroscopic measurements combined with molecular modeling were used to gain a better understanding of the coordination mode of nitrate ion around the uranyl in both water and methanol. Finally, DFT calculations were used to study the influence of the structure of the monoamide or organophosphorus ligand and their interaction with the actinides (IV, VI) including steric effects in the first coordination sphere. (author) [fr

  1. Canister storage building trade study. Final report

    International Nuclear Information System (INIS)

    Swenson, C.E.

    1995-05-01

    This study was performed to evaluate the impact of several technical issues related to the usage of the Canister Storage Building (CSB) to safely stage and store N-Reactor spent fuel currently located at K-Basin 100KW and 100KE. Each technical issue formed the basis for an individual trade study used to develop the ROM cost and schedule estimates. The study used concept 2D from the Fluor prepared ''Staging and Storage Facility (SSF) Feasibility Report'' as the basis for development of the individual trade studies

  2. 90% Compliance Pilot Studies Final Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    In early 2010, the U.S. Department of Energy (DOE) announced an opportunity for states to participate in energy code compliance evaluation pilot studies. DOE worked with five Regional Energy Efficiency Organizations (REEOs, formerly referred to as Energy Efficiency Partnerships, or EEPs) to fund pilot studies covering nine states. This report details conclusions stated in individual state reports, as well as conclusions drawn by DOE based on their oversight of the pilot studies, and based on discussions held with the REEOs and representatives from the pilot study states and their contractors.

  3. Theoretical study of ferroelectric nanoparticles using phase reconstructed electron microscopy

    DEFF Research Database (Denmark)

    Phatak, C.; Petford-Long, A. K.; Beleggia, Marco

    2014-01-01

    Ferroelectric nanostructures are important for a variety of applications in electronic and electro-optical devices, including nonvolatile memories and thin-film capacitors. These applications involve stability and switching of polarization using external stimuli, such as electric fields. We present...... a theoretical model describing how the shape of a nanoparticle affects its polarization in the absence of screening charges, and quantify the electron-optical phase shift for detecting ferroelectric signals with phase-sensitive techniques in a transmission electron microscope. We provide an example phase shift...

  4. A theoretical study on poverty | Roohbakhsh | Journal of ...

    African Journals Online (AJOL)

    ... the concepts of poverty, various approaches to poverty and its related issues such as education, health, housing and etc. are considered. Finally, measuring poverty from different researchers' views and their critical perspectives are discussed. Keywords: Poverty, Discourses on poverty, Absolute Poverty, Poverty Line ...

  5. Studies in genetic discrimination. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

  6. Bioremediation case studies: Abstracts. Final report

    International Nuclear Information System (INIS)

    Devine, K.

    1992-03-01

    The report contains abstracts of 132 case studies of bioremediation technology applied to hazardous waste clean-up. It was prepared to compile bioremediation studies in a variety of locations and treating diverse contaminants, most of which were previously undocumented. All data are based on vendor-supplied information and there was no opportunity to independently confirm its accuracy. These 132 case studies, from 10 different biotechnology companies, provide users with reference information about on-going and/or completed field applications and studies. About two-thirds of the cases were at full-scale clean-up level with the remainder at pilot or laboratory scale. In 74 percent of the cases, soil was at least one of the media treated. Soil alone accounts for 46 percent of the cases. Petroleum-related wastes account for the largest contaminant with 82 cases. Thirty-one states are represented in the case studies

  7. Gasohol: economic feasibility study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    David, M. L.; Hammaker, G. S.; Buzenberg, R. J.; Wagner, J. P.

    1978-07-01

    This report was prepared by Development Planning and Research Associates, Inc. under a contract with the Energy Research and Development Center of the University of Nebraska in cooperation with the Agricultural Products Industrial Utilization Committee and the State of Nebraska. Funding for this study was provided to the Energy Research and Development Center by the U.S. Department of Energy and the Old West Regional Commission. The primary objective of the study was to: determine the fiscal and market conditions under which the production of gasohol would be profitable for private producers. For purposes of this study, gasohol is a motor fuel consisting of 10 percent agriculturally-derived anhydrous ethanol and 90 percent unleaded gasoline. The study assumes that gasohol can be a fuel substitute for gasoline; indeed, the cost of gasoline will significantly influence that for gasohol. Gasoline prices are determined by factors external to ethanol; thus, the economic feasibility study of gasohol is in large part an economic feasibility study of fuel-grade ethanol production. More specifically, the study examined the following: the technical aspects of distributing, marketing, and using gasohol; the costs of the distribution and marketing of ethanol and gasohol; the energy balance of ethanol production; the cost of producing ethanol; the factors influencing ehtanol plant size and location; and the conditions that would make ethanol economicaly feasible for private producers.

  8. Contribution to the theoretical study of the plastic strain localization in porous materials

    International Nuclear Information System (INIS)

    Willot, F.

    2007-01-01

    This work presents a study in theoretical mechanics, in the classical framework of homogenization of heterogeneous media. It addresses a notoriously problematical situation of non-linear behavior and infinite contrast between two phases, one of which is a plastic solid phase and the other one, the porosity of the medium. Its aim is to investigate how plastic strain localization manifests itself at the level of the overall effective behavior of the medium in presence of pores, and in particular in the non-trivial limit of small porosity. This question, important to the understanding of ductile damage, is examined both numerically and theoretically, in the restricted situation of bi-dimensional systems, and using a deformation theory approach of plasticity. The numerical investigations consist of quasi-exact computations of the strain and stress fields in the voided medium, by means of a Fast Fourier Transform method, and using a particular Green function. The theoretical approach makes use of exact solutions, which can be obtained in particular cases of a periodic void lattice, as well as of a recent 'second-order' nonlinear homogenization approach. The virtues of the latter are evaluated in two steps, first by studying the underlying linear anisotropic homogenization step (an essential ingredient), then by studying the nonlinear step itself. The nature and significance of the singularities of the theory which appear in the limit of small porosity, confirmed by numerical computations, are partly elucidated. Finally, original observations are presented as to the relation between plastic deformation patterns in an ideal disordered medium, and some features of the macroscopic strain/stress curve. (author)

  9. Theoretical and experimental study of the dark signal in CMOS image sensors affected by neutron radiation from a nuclear reactor

    Science.gov (United States)

    Xue, Yuanyuan; Wang, Zujun; He, Baoping; Yao, Zhibin; Liu, Minbo; Ma, Wuying; Sheng, Jiangkun; Dong, Guantao; Jin, Junshan

    2017-12-01

    The CMOS image sensors (CISs) are irradiated with neutron from a nuclear reactor. The dark signal in CISs affected by neutron radiation is studied theoretically and experimentally. The Primary knock-on atoms (PKA) energy spectra for 1 MeV incident neutrons are simulated by Geant4. And the theoretical models for the mean dark signal, dark signal non-uniformity (DSNU) and dark signal distribution versus neutron fluence are established. The results are found to be in good agreement with the experimental outputs. Finally, the dark signal in the CISs under the different neutron fluence conditions is estimated. This study provides the theoretical and experimental evidence for the displacement damage effects on the dark signal CISs.

  10. Theoretical and experimental study of the dark signal in CMOS image sensors affected by neutron radiation from a nuclear reactor

    Directory of Open Access Journals (Sweden)

    Yuanyuan Xue

    2017-12-01

    Full Text Available The CMOS image sensors (CISs are irradiated with neutron from a nuclear reactor. The dark signal in CISs affected by neutron radiation is studied theoretically and experimentally. The Primary knock-on atoms (PKA energy spectra for 1 MeV incident neutrons are simulated by Geant4. And the theoretical models for the mean dark signal, dark signal non-uniformity (DSNU and dark signal distribution versus neutron fluence are established. The results are found to be in good agreement with the experimental outputs. Finally, the dark signal in the CISs under the different neutron fluence conditions is estimated. This study provides the theoretical and experimental evidence for the displacement damage effects on the dark signal CISs.

  11. Protonation of caffeine: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami, Hamed [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Tabrizchi, Mahmoud, E-mail: m-tabriz@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Farrokhpour, Hossein [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-03-29

    Highlights: ► Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources. ► Experimental and theoretical evidence was collected to assign the observed peaks to caffeine related ionic species. ► A new concept of “internal proton affinity”, the protonation tendency for each atom in a molecule, was defined. - Abstract: Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources, corona discharge (CD) and UV photoionization. Three peaks were observed in ion mobility spectrum by simultaneously running the two ionization sources. Experimental and theoretical evidence was collected to link the observed peaks to caffeine related ionic species. One peak was attributed to the M{sup +} ion while the other two were assigned to different protonated isomers of caffeine. In the case of CD ionization source, it was observed that different sites of caffeine compete for protonation and their relative intensities, depends on the sample concentration as well as the nature of the reactant ions. The new concept of “internal proton affinity” (IPA) was defined to express the tendency of holding the added proton for each atom in a molecule.

  12. Crystal growth, characterization and theoretical studies of 4-aminopyridinium picrate

    Science.gov (United States)

    Aditya Prasad, A.; Muthu, K.; Rajasekar, M.; Meenatchi, V.; Meenakshisundaram, S. P.

    2015-01-01

    Single crystals of 4-aminopyridinium picrate (APP) were grown by slow evaporation of a mixed solvent system methanol-acetone (1:1, v/v) containing equimolar quantities of 4-aminopyridine and picric acid. Structure is elucidated by single crystal XRD analysis and the crystal belongs to monoclinic system with four molecules in the unit cell (space group P21/c) and the cell parameter values are, a = 8.513 Å (±0.015), b = 11.33 Å (±0.02), c = 14.33 Å (±0.03) and β = 104.15° (±0.019), V = 1340 A3 (±6) with refined R factors R1 = 0.0053 and wR2 = 0.0126. The electron density mapping is interpreted to find coordinates for each atom in the crystallized molecules. The various functional groups present in the molecule are confirmed by FT-IR analysis. UV-visible spectral analysis was used to determine the band gap energy of 4-aminopyridinium picrate. Powder X-ray diffraction pattern reveals the crystallinity of the as-grown crystal and it closely resembles the simulated XRD from the single crystal XRD analysis. Scanning electron microscopy reveals the surface morphology of the grown crystal. Optimized geometry is derived by Hartree-Fock theory calculations and the first-order molecular hyperpolarizability (β), theoretically calculated bond length, bond angles and excited state energy from theoretical UV-vis spectrum were estimated.

  13. An experimental and theoretical study of the synthesis and vibrational spectroscopy of triacetone triperoxide (TATP)

    Science.gov (United States)

    Pacheco-Londono, Leonardo C.; Pena, Alvaro J.; Primera-Pedrozo, Oliva M.; Hernandez-Rivera, Samuel P.; Mina, Nairmen; Garcia, Rafael; Chamberlain, R. Thomas; Lareau, Richard T.

    2004-09-01

    Non nitrogen containing, organic peroxides explosives Triacetone triperoxide and diacetone diperoxide have been prepared in the laboratory in order to study various aspects of their synthesis and their experimental and theoretical spectroscopic characteristics. By using different proportions of acetone/hydrogen peroxide (Ac/H2O2), sulfuric, hydrochloric and methanosulfuric acids as catalyzers, it was possible to obtain both compounds in a rapid and simple form. Raman, IR spectroscopy, and GC-MS were used in order to determine the precursors, intermediates and final analytes. Experiments and theoretical studies using density functional theory (DFT) have been used in the elucidation step of the mechanism of the synthesis of the so called "transparent" explosives. The B3LYP functional with the 6-31G** basis set was used to carry out the electronic structure calculation of the intermediates and internal rotations and vibrations of TATP. Raman spectra of solid TATP and FTIR spectra of gas TATP, were recorded in order to assign the experimental spectra. Although full agreement with experiment was not obtained, spectral features of the main TATP bands were assigned.

  14. Laser fusion system design study. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    The following studies were completed: (1) The synthesis of a pointing/control system compatible with existing and advanced laser opto-mechanical configurations. (2) Attainment of the required pointing angle, longitudinal focus, and differential pathlength accuracies. (3) Maximum modularization of the sensor and gimbal assemblies to provide the required accuracies at minimum cost. Detailed information is given on each. (MOW)

  15. Geothermal reservoir insurance study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-09

    The principal goal of this study was to provide analysis of and recommendations on the need for and feasibility of a geothermal reservoir insurance program. Five major tasks are reported: perception of risk by major market sectors, status of private sector insurance programs, analysis of reservoir risks, alternative government roles, and recommendations.

  16. Nuclear safety code study. Final report

    International Nuclear Information System (INIS)

    Jackson, C.; Abumansoor, K.; Myers, E.; Jespersen, D.; Cramer, E.; O'Reilly, B.; Carmichael, B.

    1980-06-01

    An unprotected overpower accident in a Liquid Metal Fast Breeder Reactor is studied. A mathematical model and a system of partial differential equations for the temperature are derived. After spatial discretization, a large system of ordinary differential equations is obtained. The steady state version of the equations is solved analytically

  17. Final version dry cask storage study

    International Nuclear Information System (INIS)

    1989-02-01

    This report was prepared in response to Section 5064 of the Nuclear Waste Policy Amendments Act of 1987 (the Amendments Act--Public Law 100-203), which directs the Secretary of Energy to conduct a study of the use of dry-cask-storage technology for storing spent fuel at the sites of civilian nuclear reactors until a geologic repository is available. In conducting this study, whose results are being reported to the Congress, the Secretary was to consider such factors as costs, effects on human health and the environment, and the extent to which the Nuclear Waste Fund can and should be used to provide funds for at-reactor storage. In addition, the Secretary was to consult with the Nuclear Regulatory Commission (NRC), include NRC comments in the report, and solicit the views of State and local governments and the public. The study performed in response to these requirements was based largely on data published by the DOE or the NRC or included in documents issued by the DOE. Among the DOE documents are the 1987 MRS proposal to the Congress and a subsequent report, prepared to supply the Congress with additional information on the MRS facility. Because in evaluating dry storage at reactor sites it is necessary to take into account other options for meeting storage needs, this study covered all forms of at-reactor storage. 107 refs., 15 figs., 10 tabs

  18. Theoretical study of some aspects of the nucleo-bases reactivity: definition of new theoretical tools for the study of chemical reactivity

    International Nuclear Information System (INIS)

    Labet, V.

    2009-09-01

    In this work, three kinds of nucleo-base damages were studied from a theoretical point of view with quantum chemistry methods based on the density-functional theory: the spontaneous deamination of cytosine and its derivatives, the formation of tandem lesion induced by hydroxyl radicals in anaerobic medium and the formation of pyrimidic dimers under exposition to an UV radiation. The complementary use of quantitative static methods allowing the exploration of the potential energy surface of a chemical reaction, and of 'conceptual DFT' principles, leads to information concerning the mechanisms involved and to the rationalization of the differences in the nucleo-bases reactivity towards the formation of a same kind of damage. At the same time, a reflexion was undertaken on the asynchronous concerted mechanism concept, in terms of physical meaning of the transition state, respect of the Maximum Hardness Principle, and determination of the number of primitive processes involved. Finally, a new local reactivity index was developed, relevant to understand the reactivity of a molecular system in an excited state. (author)

  19. Physical protection equipment study. Final report

    International Nuclear Information System (INIS)

    Haberman, W.

    1977-06-01

    This report summarizes the work performed by MITRE for the U.S. Nuclear Regulatory Commission. The major products of this effort are a Catalog of Physical Protection Equipment, a Guide for Evaluation of Physical Protection Equipment, a book of Reference Materials, and a set of guidelines for use in the development of a methodology for measuring levels of security system effectiveness. A summary of recommendations resulting from this study is also presented

  20. Canton hydroelectric project: feasibility study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The Canton Hydroelectric Project study was undertaken to determine the feasibility of redeveloping hydroelectric power generation facilities at the Upper and Lower Dams on the Farmington River at Collinsville, CT. The integrity of the existing dams and power plants was investigated and found to be generally adequate. The intake channels, powerhouses and tailraces will require refurbishing but no major repairs. The Lower Dam will require some repair to correct surface deterioration conditions. New flashboard installations are contemplated for both the dams. Energy production operational studies were performed on 25 generating unit alternatives for the two sites. Detailed cost estimates were prepared for seven Upper and five Lower site alternatives, and a detailed economic analysis of ten project alternatives was performed. The economic analysis included 3 power marketing options and the future escalation of the value of energy. The conclusions of this study were: the project is economically feasible on a 40-y life cycle basis; short-term financing, bond payment adjustments, or other special financial arrangements will be needed to provide for the negative cash flow during the early years of operation; and the Town of Canton should further pursue the power marketing and financing aspects of the project. (LCL)

  1. Renewable Energy Feasibility Study Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rooney, Tim [Antares Group Inc.

    2013-10-30

    The Gila River Indian Community (GRIC or the Community) contracted the ANTARES Group, Inc. (“ANTARES”) to assess the feasibility of solar photovoltaic (PV) installations. A solar energy project could provide a number of benefits to the Community in terms of potential future energy savings, increased employment, environmental benefits from renewable energy generation and usage, and increased energy self-sufficiency. The study addresses a number of facets of a solar project’s overall feasibility, including: Technical appropriateness; Solar resource characteristics and expected system performance; Levelized cost of electricity (LCOE) economic assessment. The Gila River Indian Community (GRIC or the Community) contracted the ANTARES Group, Inc. (“ANTARES”) to prepare a biomass resource assessment study and evaluate the feasibility of a bioenergy project on Community land. A biomass project could provide a number of benefits to the Community in terms of increased employment, environmental benefits from renewable energy generation and usage, and increased energy self-sufficiency. The study addresses a number of facets of a biomass project’s overall feasibility, including: Resource analysis and costs; Identification of potential bioenergy projects; Technical and economic (levelized cost of energy) modeling for selected project configuration.

  2. Millimeter wave study program. Final report

    International Nuclear Information System (INIS)

    Jory, H.R.; Lien, E.L.; Symons, R.S.

    1975-11-01

    The purpose of this program was to study the various approaches to building an amplifier to produce 100 kW or more cw power at 120 GHz to decide on an optimum approach, and to perform design calculations. The study has led to the conclusion that a cyclotron resonance amplifier (gyrotron) is the optimum approach for 100 kW and that this type of interaction offers the best possibilities for going to still higher power levels. This report includes discussion in depth of all the topics and approaches considered in the study. Sections 2 and 3 deal with output waveguide and window designs. The fourth section discusses linear-beam amplifiers. The fifth section considers periodic-beam (other than cyclotron resonance) devices. Cyclotron resonance devices are considered in detail. Arguments are given leading to the choice of the gyrotron as the optimum approach in section 7. Design calculations for a 100 kW gyrotron amplifier are given based on the background and theory presented in section 6

  3. Poroelastic toughening in polymer gels: A theoretical and numerical study

    Science.gov (United States)

    Noselli, Giovanni; Lucantonio, Alessandro; McMeeking, Robert M.; DeSimone, Antonio

    2016-09-01

    We explore the Mode I fracture toughness of a polymer gel containing a semi-infinite, growing crack. First, an expression is derived for the energy release rate within the linearized, small-strain setting. This expression reveals a crack tip velocity-independent toughening that stems from the poroelastic nature of polymer gels. Then, we establish a poroelastic cohesive zone model that allows us to describe the micromechanics of fracture in gels by identifying the role of solvent pressure in promoting poroelastic toughening. We evaluate the enhancement in the effective fracture toughness through asymptotic analysis. We confirm our theoretical findings by means of numerical simulations concerning the case of a steadily propagating crack. In broad terms, our results explain the role of poroelasticity and of the processes occurring in the fracturing region in promoting toughening of polymer gels.

  4. Theoretical Advanced Study Institute in Elementary Particle Physics

    CERN Document Server

    2017-01-01

    The program will consist of a pedagogical series of lectures and seminars. Lectures will be given over a four-week period, three or four lectures per day, Monday through Friday. The audience will be composed primarily of advanced theoretical graduate students. Experimentalists with a strong background in theory are also encouraged to apply. Some post-doctoral fellows will be admitted, but preference will be given to applicants who will not have received their Ph.D. before 2017. The minimum background needed to get full benefit of TASI is a knowledge of quantum field theory (including RGEs) and familiarity with the Standard Model. Some familiarity with SUSY would be helpful. We hope to provide some subsidy, but students will need partial support from other sources. Rooms, meals, and access to all facilities will be provided at reasonable rates in beautifully located dormitories at the University of Colorado.

  5. Theoretical study of third sound in a layered superfluid film

    International Nuclear Information System (INIS)

    Cheng, E.; Saam, W.F.; Cole, M.W.; Treiner, J.

    1993-01-01

    The authors present a calculation of the third sound speed c 3 of thin 4 He films adsorbed on H 2 , Li, Mg, graphite and H 2 -plated graphite. The results show a clear correlation of oscillations in c 3 , with a period of one atomic layer, with the layering phenomena observed in adsorption isotherms. Comparison is made with recent experimental results for helium films on solid H 2 by Shirron and Mochel and by Brisson, Mester and Silvera. The theoretical analysis suggests explanations for disagreements between different interpretations of data. A standard way of determining the number of so-called inert layers is questioned. Other available experimental data on graphite and H 2 -plated graphite are also discussed

  6. Ramakrishna Mission initiative impact study: final report

    Energy Technology Data Exchange (ETDEWEB)

    Chaurey, A.

    2000-07-06

    This report has been prepared by the Tata Energy Research Institute (TERI) for the National Renewable Energy Laboratory. It presents the results of the evaluation and impact assessment of solar photovoltaic lighting systems in the region of Sunderbans, West Bengal, that were deployed by a reputable non-governmental organization (Ramakrishna Mission) under the auspices of the INDO-US collaborative project. The objectives of the study were to evaluate the solar photovoltaic systems for their impact on the individual households as well as on the community, to assess the effectiveness of the implementation and financial mechanisms, and to draw a long-term strategy for NREL's activities in Sunderbans based on case studies of similar interventions. Under the project, provision was made to supply 300 domestic lighting systems (DLS) based on 53-Wp module capacity to individual households and a few other systems such as for lighting, medical refrigeration, and pumping water to community centers. For this study, 152 households were surveyed, of which 29 had also been a part of earlier pre- and post-installation surveys, 47 had been a part of the earlier post-installation survey, and 76 were households that were surveyed for the first time. A set of 46, out of the total 152 households, was selected for evaluating the systems for their technical performance with respect to module output, condition of the battery, and daily energy consumption. Of the total 300 modules, 2 had been stolen, 9 out of the total 300 batteries needed to be replaced, and 10 out of the 300 charge controllers were non-functional. The statistics for the surveyed households indicate 32 luminaire-related faults (blackening or flickering of compact fluorescent lights) and 11 other faults related to fuses, switches, etc.

  7. Molten salt safety study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The considerations concerning safety in using molten salt (40% potassium nitrate, 60% sodium nitrate) in a solar central receiver plant are addressed. The considerations are of a general nature and do not cover any details of equipment or plant operation. The study includes salt chemical reaction, experiments with molten salt, dry storage and handling constraints, and includes data from the National Fire Protection Association. The contents of this report were evaluated by two utility companies and they concluded that no major safety problems exist in using a molten salt solar system.

  8. Theoretical and computational studies in protein folding, design, and function

    Science.gov (United States)

    Morrissey, Michael Patrick

    2000-10-01

    In this work, simplified statistical models are used to understand an array of processes related to protein folding and design. In Part I, lattice models are utilized to test several theories about the statistical properties of protein-like systems. In Part II, sequence analysis and all-atom simulations are used to advance a novel theory for the behavior of a particular protein. Part I is divided into five chapters. In Chapter 2, a method of sequence design for model proteins, based on statistical mechanical first-principles, is developed. The cumulant design method uses a mean-field approximation to expand the free energy of a sequence in temperature. The method successfully designs sequences which fold to a target lattice structure at a specific temperature, a feat which was not possible using previous design methods. The next three chapters are computational studies of the double mutant cycle, which has been used experimentally to predict intra-protein interactions. Complete structure prediction is demonstrated for a model system using exhaustive, and also sub-exhaustive, double mutants. Nonadditivity of enthalpy, rather than of free energy, is proposed and demonstrated to be a superior marker for inter-residue contact. Next, a new double mutant protocol, called exchange mutation, is introduced. Although simple statistical arguments predict exchange mutation to be a more accurate contact predictor than standard mutant cycles, this hypothesis was not upheld in lattice simulations. Reasons for this inconsistency will be discussed. Finally, a multi-chain folding algorithm is introduced. Known as LINKS, this algorithm was developed to test a method of structure prediction which utilizes chain-break mutants. While structure prediction was not successful, LINKS should nevertheless be a useful tool for the study of protein-protein and protein-ligand interactions. The last chapter of Part I utilizes the lattice to explore the differences between standard folding, from

  9. A theoretical study of bubble motion in surfactant solutions

    Science.gov (United States)

    Wang, Yanping

    1999-08-01

    We examine the effect of surfactants on a spherical gas bubble rising steadily in an infinite fluid at low and order one Reynolds number with order one and larger Peclet numbers. Our mathematical model is based on the Navier-Stokes equations coupled with a convection- diffusion equation together with appropriate interfacial conditions. The nonlinearity of the equations and boundary conditions, and the coupling between hydrodynamics and surfactant transport make the problem very challenging. When a bubble rises in a fluid containing surface-active agents, surfactant adsorbs onto the bubble surface at the leading edge, convects to the trailing edge by the surface flow and desorbs into the bulk along the interface. This adsorption develops a surface concentration gradient on the interface that makes the surface tension at the back end relatively lower than that at the front end, and thus retards the bubble velocity. Because of surfactant impurities unavoidably present in materials, this retardation can cause a problem in materials processing in space and glass processing when bubbles are created during chemical reactions. Thus the study of how to remobilize (remove the surfactant gradient on the surface) the bubble surface becomes necessary. Many studies have been done on this retarding effects of the surfactant on a moving bubble. However, most were focused on the retarding effect due to a trace amount of surfactant, in which case the bubble velocity monotonically decreases as the bulk concentration increases. The question of how to remobilize the bubble surface remains unanswered. In this work, we will show that the bubble velocity can be controlled by remobilizing the bubble interface using the surfactant concentration. This technique not only can be used to maximize the bubble velocity, but also can be used to maximize mass transfer on purifying materials and extracting materials from mixtures. In the first part of the work, we illustrate numerically that the

  10. Adsorption isotherm special study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-05-01

    The study was designed to identify methods to determine adsorption applicable to Uranium Mill Tailings Remedial Action (UMTRA) Project sites, and to determine how changes in aquifer conditions affect metal adsorption, resulting retardation factors, and estimated contaminant migration rates. EPA and ASTM procedures were used to estimate sediment sorption of U, As, and Mo under varying groundwater geochemical conditions. Aquifer matrix materials from three distinct locations at the DOE UMTRA Project site in Rifle, CO, were used as the adsorbents under different pH conditions; these conditions stimulated geochemical environments under the tailings, near the tailings, and downgradient from the tailings. Grain size, total surface area, bulk and clay mineralogy, and petrography of the sediments were characterized. U and Mo yielded linear isotherms, while As had nonlinear ones. U and Mo were adsorbed strongly on sediments acidified to levels similar to tailings leachate. Changes in pH had much less effect on As adsorption. Mo was adsorbed very little at pH 7-7.3, U was weakly sorbed, and As was moderately sorbed. Velocities were estimated for metal transport at different pHs. Results show that the aquifer materials must be characterized to estimate metal transport velocities in aquifers and to develop groundwater restoration strategies for the UMTRA project.

  11. Pinellas Plant feasibility study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    The Pinellas Plant was built in 1956 to manufacture neutron generators, a principal component in nuclear weapons. In September 1990, the Department of Health and Rehabilitative Services (HRS) entered into an agreement with DOE to independently examine environmental monitoring data from the plant and health data from Pinellas County to determine if an epidemiological study is technically feasible to measure possible off-site health effects from ionizing radiation. Through normal plant operations, some radioactive materials have been released to the environment. Eighty percent of the total plant releases of 107,707 curies occurred in the early years of plant operation (1957--1960). The primary materials released were tritium gas, tritium oxide and krypton-85. Environmental monitoring for radioactive releases from the plant has been done regularly since 1975. The US Public Health Service Centers for Disease Control and Prevention (CDC), in assisting HRS, has determined that sufficient radiological data exist by which a dose reconstruction can be done. A dose reconstruction can provide an estimate of how much radiological exposure someone living in the vicinity of the Pinellas Plant may have suffered from environmental releases.

  12. Study of The Final Customer Loyalty Process

    Directory of Open Access Journals (Sweden)

    Juan Carlos Fandos

    2013-12-01

    Full Text Available For any business is important to maintain a loyal customer base to help they to survive over time. This situation is accentuated even to the extent that increases competition and increases uncertainty. At present these are two features that are really developed. Because of the deep crisis in which we are, and other elements such as globalization and the development of new technologies and communication systems, we are faced with a scenario of intense competition and uncertainty manifest. It is therefore more necessary than ever to know in depth how to get customers to be faithful, and develop true loyalty strategies.In this paper, we present the sequential approach to the formation of consumer loyalty in order to deepen understanding of the concept. It is supplemented by studying the combined effect of switching costs as an element that promotes the continuity of the relationship. The results shows that the consumer takes a more cognitive process information in their initial assessments of the service and therefore in the early stages of loyalty. As advances in consumer behavior process becomes more direct and mechanic, so we can say that the customer-company bond is stronger.

  13. Adsorption isotherm special study. Final report

    International Nuclear Information System (INIS)

    1993-05-01

    The study was designed to identify methods to determine adsorption applicable to Uranium Mill Tailings Remedial Action (UMTRA) Project sites, and to determine how changes in aquifer conditions affect metal adsorption, resulting retardation factors, and estimated contaminant migration rates. EPA and ASTM procedures were used to estimate sediment sorption of U, As, and Mo under varying groundwater geochemical conditions. Aquifer matrix materials from three distinct locations at the DOE UMTRA Project site in Rifle, CO, were used as the adsorbents under different pH conditions; these conditions stimulated geochemical environments under the tailings, near the tailings, and downgradient from the tailings. Grain size, total surface area, bulk and clay mineralogy, and petrography of the sediments were characterized. U and Mo yielded linear isotherms, while As had nonlinear ones. U and Mo were adsorbed strongly on sediments acidified to levels similar to tailings leachate. Changes in pH had much less effect on As adsorption. Mo was adsorbed very little at pH 7-7.3, U was weakly sorbed, and As was moderately sorbed. Velocities were estimated for metal transport at different pHs. Results show that the aquifer materials must be characterized to estimate metal transport velocities in aquifers and to develop groundwater restoration strategies for the UMTRA project

  14. DER Benefits Analysis Studies: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Iannucci, J. J.; Cibulka, L.; Eyer, J. M.; Pupp, R. L.

    2003-09-01

    The electric power industry in the United States is undergoing dramatic change. Once totally controlled by utilities that had monopolistic holds on the supply, transmission and distribution of electricity in their service areas, the electric power system is being deregulated, introducing competition among electricity providers who can distinguish themselves by price, services and other factors. The new electric power system will feature advanced technologies and services that can be used on-site or located in close proximity to the load, instead of depending solely upon large, central station generation and transmission. Using a variety of advanced modular generating technologies (including small-scale renewables), distributed energy resource (DER) plants supply base-load power, peaking power, backup power, remote power and/or heating and cooling, and in some cases supply higher and more reliable quality power. Currently, DER represent a minor part of the electric supply system. If the potential of DER is to be realized in the new electric power market, a full understanding of the value and benefits these technologies provide to the electric system is necessary. This report includes 30 key quantitative studies reporting on the values and benefits of distributed energy generation technologies (including renewables) in various applications, as well as a matrix that permits key comparisons.

  15. Pinellas Plant feasibility study. Final report

    International Nuclear Information System (INIS)

    1994-09-01

    The Pinellas Plant was built in 1956 to manufacture neutron generators, a principal component in nuclear weapons. In September 1990, the Department of Health and Rehabilitative Services (HRS) entered into an agreement with DOE to independently examine environmental monitoring data from the plant and health data from Pinellas County to determine if an epidemiological study is technically feasible to measure possible off-site health effects from ionizing radiation. Through normal plant operations, some radioactive materials have been released to the environment. Eighty percent of the total plant releases of 107,707 curies occurred in the early years of plant operation (1957--1960). The primary materials released were tritium gas, tritium oxide and krypton-85. Environmental monitoring for radioactive releases from the plant has been done regularly since 1975. The US Public Health Service Centers for Disease Control and Prevention (CDC), in assisting HRS, has determined that sufficient radiological data exist by which a dose reconstruction can be done. A dose reconstruction can provide an estimate of how much radiological exposure someone living in the vicinity of the Pinellas Plant may have suffered from environmental releases

  16. Uranium miner lung cancer study. Final report

    International Nuclear Information System (INIS)

    Saccomanno, G.

    1986-06-01

    This study on uranium miners was started in 1957 and extended through June 30, 1986. It consisted of the routine screening of sputum from uranium miners of the Colorado Plateau, and collection of surgical and autopsy material from uranium miners who developed lung cancer. The projects resulted in: (1) Proof, for the first time, that cancer takes from 10 to 15 years to develop from the maximum accumulated carcinogenic insult and can be demonstrated through progressive cellular changes of the bronchial tree; (2) Development of a method for preserving, concentrating, and processing sputum samples. This is known as the Saccomanno Technique, and is used worldwide in diagnosing lung cancer; (3) Publication of the 1st and 2nd editions of a full-color textbook entitled ''Diagnostic Pulmonary Cytology;'' (4) Presentation of conclusive data on the effects of cigarette smoking and alpha progeny radiation on uranium miners, and information on safe radiation exposure levels; (5) Development of a brush-wash tube for collecting, concentrating, and preparing bronchial brushings and washings; (6) Development of cytological criteria which has improved sensitivity from 30% to about 60%; (7) Development of criteria for cytologic identification of carcinoma in situ, making it possible to diagnose lung cancer before it can be detected on chest x-ray

  17. Environmental and Social Impact Study: Final Report

    International Nuclear Information System (INIS)

    2011-04-01

    The tsetse control project (commonly known as tsetse flies) is an initiative of the Directorate of Livestock (project coordinating institution) and the ISRA (Senegalese Agricultural Research Institute) Accompaniment and diagnosis of the project. It is part of the cooperation between Senegal and the International Atomic Energy Agency (IAEA).The method of control that will be applied is the technique of sterile males.This technique of sterile males, however, is coupled with the use of deltamethrin (D6), a neurotoxic chemical (in adult insects) that is fast and fairly rapidly biodegradable in the environment.This study is carried out with the aim of taking good account of the environmental impacts of the various activities envisaged by the project. Its objective is to assess the biophysical, social and economic impacts of the project and to propose measures to mitigate or compensate for negative impacts and to reinforce positive impacts within the framework of an Environmental Management Plan and (ESMP). It also presents an environmental and social monitoring and monitoring plan to assess the effectiveness of the proposed mitigation measures.

  18. New Particle Formation Study Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, JN; McMurry, PH [University of Minnesota

    2015-01-01

    The scientific foci of the New Particle Formation Study were the formation and evolution of atmospheric aerosols and the impacts of newly formed particles on cloud processes. Specifically, we planned to: (1) to identify the species and mechanisms responsible for the initial steps of new particle formation, i.e., the formation of thermodynamically stable clusters; (2) investigate the role of acid-base chemistry in new particle growth through measurements of ammonia and amines as well as organic and inorganic acids in both atmospheric nanoparticles and the gas phase; (3) investigate the contribution of other surface area or volume-controlled processes to nanoparticle formation and growth; (4) create a comprehensive dataset related to new particle formation and growth that can be used as input for our own thermodynamic models as well as the modeling efforts by our Department of Energy (DOE) Aerosol Life Cycle working group collaborators; (5) characterize the increase of the number and activity of cloud condensation nuclei (CCN) due to particle formation and growth; (6) determine the regional extent of new particle formation to address the role that atmospheric transport plays in determining the impacts, if any, of new particle formation on cloud number and properties.

  19. Theoretical studies of structure and dynamics of chalcogenide glasses

    Science.gov (United States)

    Inam, Fakharul

    In this work, the structural and dynamical properties of Ge-Se and Ag-Ge-Se glasses, using first principle molecular dynamics simulations, is presented. Raman and calorimetric studies on GeXSe1- x glasses have provided evidence for the existence of the intermediate phase (IP) in chalcogenides and other glasses. Here we thoroughly discuss the ab-initio models of Ge XSe1-x glasses over a wide composition range and provide an atomistic picture of the IP. A thorough analysis of our models reveals that the IP in these glasses may arise from the competition between amorphous GeSe2 and a polymeric a-Se phases, which gives rise to the non-monotonic evolution (a topological feature of the IP) of the network parameters through the IP window. A qualitative comparison is made between the topological features extracted from the models and the experiments. A possible electronic signature of the IP in terms of the shift in the conduction edge energy in the IP range is predicted. The results agree with the shift in the white line position for the Se atoms in the K-edge X-Ray Absorption Near Edge Structure (XANES) spectra. A microscopic picture of the silver dynamics in GeSe3 :Ag glass is presented. The dynamics of Ag is explored at two temperatures: 300K and 700K. In the relaxed GeSe3 glass network, it is shown that the Ag occupies trapping centers (TC) that exist between pairs of suitably separated host sites. The charge state of the Ag in the glass network is computed and it is shown that Ag is neutral if weakly bonded and is Ag+ if in a trapping center. The dynamics of the Ag is shown to be largely effected by the neighboring host sties. At room temperature, Ag is mainly trapped at the TC with small hopping probability between neighboring TCs. At higher temperature (700 K), the Ag motion is diffusive and is proceeded via a trapping-release dynamics between supertraps or cages consisting of multiple trapping center sites in a small volume. Our work offers a first

  20. Theoretical and experimental studies on in-plane stiffness of integrated container structure

    Directory of Open Access Journals (Sweden)

    Xiaoxiong Zha

    2016-03-01

    Full Text Available This article presents analytical, numerical, and experimental studies on the in-plane stiffness of container buildings. First, based on diaphragm theory, parallel corrugated direction stiffness of corrugated sheet has been deduced, and based on energy method, shear modulus of two elastic principal directions of orthotropic plate has been deduced, and through stiffness conversion method, the stiffness relationship between parallel corrugated direction and vertical corrugated direction has been obtained. Combined with container frame, the container stiffness of loading end and non-loading end, as bottom side beam fixed, has been obtained. Second, through the software Abaqus, full-scale container model has been established. The loading–displacement curve of finite element model has been compared with theoretical analysis and has a good agreement. Third, through 20 and 40 ft container, corresponding experimental verification has been done, and by comparison of container stiffness, the theoretical analysis and finite element simulation have been verified. Finally, based on verified finite element model, parametric analysis of corrugated sheet size, corrugated sheeting cross section, elasticity modulus of top side beam, and every plate action for container stiffness have been given. Research result has made feasible in design and construction of container buildings and can provide some references to corresponding specification preparation.

  1. Wear Processes in a Mechanical Friction Clutch: Theoretical, Numerical, and Experimental Studies

    Directory of Open Access Journals (Sweden)

    Dariusz Grzelczyk

    2015-01-01

    Full Text Available Mathematical modeling, theoretical/numerical analysis, and experimental verification of wear processes occurring on the contact surface of friction linings of a mechanical friction clutch are studied. In contrast to many earlier papers we take into consideration wear properties and flexibility of friction materials being in friction contact. During mathematical modeling and numerical simulations we consider a general nonlinear differential model of wear (differential wear model and a model of wear in the integral form (integral wear model. Equations governing contact pressure and wear distributions of individual friction linings, decrease of distance between clutch shields, and friction torque transmitted by the clutch are derived and compared with experimental data. Both analytical and numerical analyses are carried out with the qualitative and quantitative theories of differential and integral equations, including the Laplace transform approach to ODEs. We show that theoretical results and numerical simulations agree with the experimental data. Finally, a numerical analysis of the proposed mathematical models was carried out in a wider range of parameters of the considered system.

  2. Microbial field pilot study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m{sup 3}) of tertiary oil have been recovered. Microbial activity has increased CO{sub 2} content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  3. We need theoretical physics approaches to study living systems

    Science.gov (United States)

    Blagoev, Krastan B.; Shukla, Kamal; affil="3" >Herbert Levine,

    2013-08-01

    Living systems, as created initially by the transition from assemblies of large molecules to self-reproducing information-rich cells, have for centuries been studied via the empirical toolkit of biology. This has been a highly successful enterprise, bringing us from the vague non-scientific notions of vitalism to the modern appreciation of the biophysical and biochemical bases of life. Yet, the truly mind-boggling complexity of even the simplest self-sufficient cells, let alone the emergence of multicellular organisms, of brain and consciousness, and to ecological communities and human civilizations, calls out for a complementary approach. In this editorial, we propose that theoretical physics can play an essential role in making sense of living matter. When faced with a highly complex system, a physicist builds simplified models. Quoting Philip W Anderson's Nobel prize address, 'the art of model-building is the exclusion of real but irrelevant parts of the problem and entails hazards for the builder and the reader. The builder may leave out something genuinely relevant and the reader, armed with too sophisticated an experimental probe, may take literally a schematized model. Very often such a simplified model throws more light on the real working of nature....' In his formulation, the job of a theorist is to get at the crux of the system by ignoring details and yet to find a testable consequence of the resulting simple picture. This is rather different than the predilection of the applied mathematician who wants to include all the known details in the hope of a quantitative simulacrum of reality. These efforts may be practically useful, but do not usually lead to increased understanding. To illustrate how this works, we can look at a non-living example of complex behavior that was afforded by spatiotemporal patterning in the Belousov-Zhabotinsky reaction [1]. Physicists who worked on this system did not attempt to determine all the relevant chemical intermediates

  4. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    1989-08-01

    During the past year, research in theoretical nuclear physics at the University of Maryland attained a number of exciting and important results. These are described in some detail throughout the report, but some of the highlights are as follows: large N c QCD has been shown to place strong constraints on vacuum effects of hadronic field theories; color dielectric models of hadrons have been understood in terms of lattice QCD; we have completed a relativistic analysis of proton scattering to test virtual pair contributions; we have also re-derived the Mandelzweig-Wallace two-body Dirac equation in covariant form, and applied it to the atomic two-body bound states: hydrogen, muonium and positronium; we have carried out the first calculation of the triton binding energy with a realistic quark-based nucleon-nucleon interaction and have learned that new kinds of nonlocalities in the tensor force may produce unexpected results; and we have shown that the Quadronium Conjecture can lead to spontaneous creation of the atom with low momentum as required by the observations, and are constructing a model to quantify the Quadronium phenomenology of the e + e - Puzzle

  5. Theoretical studies in medium-energy nuclear and hadronic physics

    International Nuclear Information System (INIS)

    Horowitz, C.J.; Macfarlane, M.H.; Matsui, T.; Serot, B.D.

    1993-01-01

    A proposal for theoretical nuclear physics research is made for the period April 1, 1993 through March 31, 1996. Research is proposed in the following areas: relativistic many-body theory of nuclei and nuclear matter, quasifree electroweak scattering and strange quarks in nuclei, dynamical effects in (e,e'p) scattering at large momentum transfer, investigating the nucleon's parton sea with polarized leptoproduction, physics of ultrarelativistic nucleus endash nucleus collisions, QCD sum rules and hadronic properties, non-relativistic models of nuclear reactions, and spin and color correlations in a quark-exchange model of nuclear matter. Highlights of recent research, vitae of principal investigators, and lists of publications and invited talks are also given. Recent research dealt primarily with medium-energy nuclear physics, relativistic theories of nuclei and the nuclear response, the nuclear equation of state under extreme conditions, the dynamics of the quark endash gluon plasma in relativistic heavy-ion collisions, and theories of the nucleon endash nucleon force

  6. A unified theoretical and experimental study of anisotropic hardening

    International Nuclear Information System (INIS)

    Boehler, J.P.; Raclin, J.

    1981-01-01

    The purpose of this work is to develop a consistent formulation of the constitutive relations regarding anisotropic hardening materials. Attention is focused on the appearance and the evolution of mechanical anisotropies during irreversible processes, such as plastic forming and inelastic deformation of structures. The representation theorems for anisotropic tensor functions constitute a theoretical basis, allowing to reduce arbitrariness and to obtain a unified formulation of anisotropic hardening. In this approach, a general three-dimensional constitutive law is developed for prestrained initially orthotropic materials. Introduction of the plastic behavior results in the general forms of both the flow-law and the yield criterion. The developed theory is then specialized for the case of plane stress and different modes of anisotropic hardening are analyzed. A new generalization of the Von Mises criterion is proposed, in considering a homogeneous form of order two in stress and employing the simplest combinations of the basic invariants entering the general form of the yield condition. The proposed criterion involves specific terms accounting for the initial anisotropy, the deformation induced anisotropy and correlative terms between initial and induced anisotropy. The effects of prestrainings result in both isotropic and anisotropic hardening. An adequate experimental program, consisting of uniaxial tensile tests on oriented specimens of prestrained sheet-metal, was performed, in order to determine the specific form and the evolution of the anisotropic failure criterion for soft-steel subjected to different irreversible prestrainings. (orig.)

  7. Final Report on Pilot Studies / Final Report on Classroom Research with STEM and TESL Assessment

    DEFF Research Database (Denmark)

    Biel, Carmen; Wake, Jo Dugstad; Hesse, Friedrich

    This Deliverable is the final report on pilot studies within the NEXT-TELL project (D6.7) and furthermore comprises the Deliverable on Classroom Research with STEM and TESL Assessment (D2.9) in order to avoid redundancies between those two Deliverables.......This Deliverable is the final report on pilot studies within the NEXT-TELL project (D6.7) and furthermore comprises the Deliverable on Classroom Research with STEM and TESL Assessment (D2.9) in order to avoid redundancies between those two Deliverables....

  8. Laser fusion systems design study. Final technical report

    International Nuclear Information System (INIS)

    1975-06-01

    This document is an addendum to Perkin-Elmer Report No. 12486, Final Technical Report, Laser Fusion System Analysis. Contained herein are the budgetary cost estimates prepared for the baseline design described in the Final Technical Report. Cost tradeoffs performed during the study are covered. (U.S.)

  9. Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Chan [Univ. of California, Los Angeles, CA (United States); Mori, W. [Univ. of California, Los Angeles, CA (United States)

    2013-10-21

    This is the final report on the DOE grant number DE-FG02-92ER40727 titled, “Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators.” During this grant period the UCLA program on Advanced Plasma Based Accelerators, headed by Professor C. Joshi has made many key scientific advances and trained a generation of students, many of whom have stayed in this research field and even started research programs of their own. In this final report however, we will focus on the last three years of the grant and report on the scientific progress made in each of the four tasks listed under this grant. Four tasks are focused on: Plasma Wakefield Accelerator Research at FACET, SLAC National Accelerator Laboratory, In House Research at UCLA’s Neptune and 20 TW Laser Laboratories, Laser-Wakefield Acceleration (LWFA) in Self Guided Regime: Experiments at the Callisto Laser at LLNL, and Theory and Simulations. Major scientific results have been obtained in each of the four tasks described in this report. These have led to publications in the prestigious scientific journals, graduation and continued training of high quality Ph.D. level students and have kept the U.S. at the forefront of plasma-based accelerators research field.

  10. Final report to the DOE for the period 8/1/96 to 5/31/00 by the SCRI Theoretical High Energy Group

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Urs

    2000-11-29

    This is the final report on grant DE-FG05-96ER40979 from the US Department of Energy supporting the research of the Theoretical High Energy Physics group at the Supercomputer Computations Research Institute (SCRI) at Florida State University. The research primarily involved lattice field theory simulations such as Quantum Chromodynamics (QCD). Although QCD is generally accepted as the theory which describes the strong interactions responsible for nuclear binding, convincing computations of the properties of the elementary particles from first principles are still elusive. The problem lies in the fact that for data at the low energies involved ({approx} 1 GeV), the coupling constant in QCD is large, preventing application of the physicist's usual tool, perturbation theory. Non-perturbative computations are necessary and they appear possible only via large scale numerical simulations. Especially simulations of full QCD, including the effect of light dynamical quarks, are extremely CPU time consuming. The scientists in SCRI's lattice gauge theory group have been in the forefront of such numerical simulations since the inception of SCRI in 1985. A major research topic was the study of improved lattice actions, designed to diminish finite lattice spacing effects and thus accelerate the approach to the continuum limit. Most of this work was carried out in the quenched approximation. Very encouraging results were obtained. In the second half of the funding period, a major focus of the group has been the use of a new lattice fermion representation, Overlap fermions, that has achieved the much desired goal of preserving the chiral symmetry properties of the continuum theory at finite lattice spacing. After developing an algorithm for the numerical simulations of overlap fermions, the SCRI group has completed the first studies of the relation between chiral symmetry breaking and topology using this new formalism.

  11. Improvement of measurements, theoretical computations and evaluations of neutron induced helium production cross sections. Summary report on the third and final research co-ordination meeting

    International Nuclear Information System (INIS)

    Pashchenko, A.B.

    1996-09-01

    The present report contains the Summary of the Third and Final IAEA Research Co-ordination Meeting (RCM) on ''Improvement of Measurements, Theoretical Computations and Evaluations of Neutron Induced Helium Production Cross Sections'' which was hosted by the Tohoku University and held in Sendai, Japan, from 25 to 29 September 1995. This RCM was organized by the IAEA Nuclear Data Section (NDS), with the co-operation and assistance of local organizers from Tohoku University. Summarized are the proceedings and results of the meeting. The List of Participants and meeting Agenda are included. (author)

  12. Theoretical Studies of Spectroscopic Line Mixing in Remote Sensing Applications

    Science.gov (United States)

    Ma, Q.

    2015-12-01

    The phenomenon of collisional transfer of intensity due to line mixing has an increasing importance for atmospheric monitoring. From a theoretical point of view, all relevant information about the collisional processes is contained in the relaxation matrix where the diagonal elements give half-widths and shifts, and the off-diagonal elements correspond to line interferences. For simple systems such as those consisting of diatom-atom or diatom-diatom, accurate fully quantum calculations based on interaction potentials are feasible. However, fully quantum calculations become unrealistic for more complex systems. On the other hand, the semi-classical Robert-Bonamy (RB) formalism, which has been widely used to calculate half-widths and shifts for decades, fails in calculating the off-diagonal matrix elements. As a result, in order to simulate atmospheric spectra where the effects from line mixing are important, semi-empirical fitting or scaling laws such as the ECS and IOS models are commonly used. Recently, while scrutinizing the development of the RB formalism, we have found that these authors applied the isolated line approximation in their evaluating matrix elements of the Liouville scattering operator given in exponential form. Since the criterion of this assumption is so stringent, it is not valid for many systems of interest in atmospheric applications. Furthermore, it is this assumption that blocks the possibility to calculate the whole relaxation matrix at all. By eliminating this unjustified application, and accurately evaluating matrix elements of the exponential operators, we have developed a more capable formalism. With this new formalism, we are now able not only to reduce uncertainties for calculated half-widths and shifts, but also to remove a once insurmountable obstacle to calculate the whole relaxation matrix. This implies that we can address the line mixing with the semi-classical theory based on interaction potentials between molecular absorber and

  13. Theoretical studies of mutual diffusivities and surface properties in ...

    Indian Academy of Sciences (India)

    properties, thus underlining the importance of thermodynamic studies for liquid binary alloys. In this study, the transport and surface properties of Cd–Ga liquid alloys are determined from energetics and derivatives from experimental thermodynamic data. Cd–Ga alloys have been studied by many authors [14–16]. The alloy ...

  14. Expanded studies of linear collider final focus systems at the Final Focus Test Beam

    Energy Technology Data Exchange (ETDEWEB)

    Tenenbaum, Peter Gregory [Stanford Univ., CA (United States)

    1995-12-01

    In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (horizontal) by 60 manometers (vertical). In order to achieve the desired spot sizes, the FFTB beam optics must be tuned to eliminate aberrations and other errors, and to ensure that the optics conform to the desired final conditions and the measured initial conditions of the beam. Using a combination of incoming-beam diagnostics. beam-based local diagnostics, and global tuning algorithms, the FFTB beam size has been reduced to a stable final size of 1.7 microns by 70 manometers. In addition, the chromatic properties of the FFTB have been studied using two techniques and found to be acceptable. Descriptions of the hardware and techniques used in these studies are presented, along with results and suggestions for future research.

  15. Expanded studies of linear collider final focus systems at the Final Focus Test Beam

    International Nuclear Information System (INIS)

    Tenenbaum, P.G.

    1995-12-01

    In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (horizontal) by 60 manometers (vertical). In order to achieve the desired spot sizes, the FFTB beam optics must be tuned to eliminate aberrations and other errors, and to ensure that the optics conform to the desired final conditions and the measured initial conditions of the beam. Using a combination of incoming-beam diagnostics. beam-based local diagnostics, and global tuning algorithms, the FFTB beam size has been reduced to a stable final size of 1.7 microns by 70 manometers. In addition, the chromatic properties of the FFTB have been studied using two techniques and found to be acceptable. Descriptions of the hardware and techniques used in these studies are presented, along with results and suggestions for future research

  16. Heavy leptons: theoretical study of the implications of their existence

    International Nuclear Information System (INIS)

    Ragiadakos, C.

    1978-01-01

    The following points are studied: the possibility of an internal structure of heavy leptons and its manifestation; a study of the production of neutral heavy leptons in e + -e - collisions; consequences of the lumaton (heavy lepton having strong interactions) hypothesis; the introduction of a muon number violating mechanism in gauge theories. A gauge model characterized by the symmetries: left-right and quarks-leptons is also studied. A general review of the heavy leptons is given [fr

  17. A theoretical study on the B3 phases of ZnSe: Structural and ...

    Indian Academy of Sciences (India)

    KHOIROM Kabita

    2017-06-20

    Jun 20, 2017 ... fabrication of blue light emitting diodes, quantum well devices, infrared window lenses etc. It crystallizes in four-fold coordinated zinc-blende (ZB) structure that is in B3 phase under ambient pressure. ZnSe is intensively studied, experimentally as well as theoretically, using different methods. Theoretical ...

  18. Joint Experimental and Theoretical Study on Vibrational Excitation Cross Sections for Electron Collisions with Diacetylene

    Czech Academy of Sciences Publication Activity Database

    Čurík, Roman; Paidarová, Ivana; Allan, M.; Čársky, Petr

    2014-01-01

    Roč. 118, č. 41 (2014), s. 9734-9744 ISSN 1089-5639 R&D Projects: GA ČR GAP208/11/0452; GA MŠk LD14088 Institutional support: RVO:61388955 Keywords : diacetylenes * electron collision * theoretical study Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.693, year: 2014

  19. Theoretical study of diaquamalonatozinc(II) single crystal for ...

    Indian Academy of Sciences (India)

    MITESH CHAKRABORTY

    2017-11-28

    Nov 28, 2017 ... trons with non-zero spin [1,2]. Studies using electron magnetic resonance (EMR) spectroscopy or electron spin resonance (ESR) spectroscopy provide information about zero field splitting (ZFS) parameters and local site symmetry of transition metal ions doped in diamagnetic host [3,4]. Studies of electronic ...

  20. Experimental and theoretical study of precast beam-slab construction

    African Journals Online (AJOL)

    Part of the experimental program was dedicated to the study of mix design for the production of suitable hollow concrete beam tiles which bridge the space between the precast beam elements. The second part of the test program included the study of the precast beam element alone in order to investigate the response ...

  1. Theoretical Cognitive Principles Observed in the Social Studies Classroom

    Science.gov (United States)

    Walker, Juan; Langan, Elise; Kemp, Andrew; Pagnotti, John; Russell, William

    2016-01-01

    Pre-service elementary social studies teachers in the south eastern United States participated in a mixed methods study to determine the degree to which they utilized critical thinking skills. Insight Assessments administered analysis of their reflections, critical thinking skills, and dispositions test. The researchers developed a post survey for…

  2. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle

  3. Theoretical study on the structural effect of some organic ...

    African Journals Online (AJOL)

    A quantitative structure property relationship (QSPR) analysis of some organic compounds (imines or Schiff bases) is studied. The corrosion inhibition efficiencies of these imines have been studied by using AM1 (Austin model 1) Hamiltonian SCF-MO method and QSPR analysis. One of the most promising semiempirical ...

  4. Theoretical and Experimental Studies of Magneto-Rayleigh-Taylor Instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Yue Ying [University of Michigan, Ann Arbor, MI (United States); Gilgenbach, Ronald [University of Michigan, Ann Arbor, MI (United States)

    2013-07-07

    Magneto-Rayleigh-Taylor instability (MRT) is important to magnetized target fusion, wire-array z-pinches, and equation-of-state studies using flyer plates or isentropic compression. It is also important to the study of the crab nebula. The investigators performed MRT experiments on thin foils, driven by the mega-ampere linear transformer driver (LTD) facility completed in their laboratory. This is the first 1-MA LTD in the USA. Initial experiments on the seeding of MRT were performed. Also completed was an analytic study of MRT for a finite plasma slab with arbitrary magnetic fields tangential to the interfaces. The effects of magnetic shear and feedthrough were analyzed.

  5. Experimental and Theoretical Studies in Hydrogen-Bonding Organocatalysis

    Directory of Open Access Journals (Sweden)

    Matej Žabka

    2015-08-01

    Full Text Available Chiral thioureas and squaramides are among the most prominent hydrogen-bond bifunctional organocatalysts now extensively used for various transformations, including aldol, Michael, Mannich and Diels-Alder reactions. More importantly, the experimental and computational study of the mode of activation has begun to attract considerable attention. Various experimental, spectroscopic and calculation methods are now frequently used, often as an integrated approach, to establish the reaction mechanism, the mode of activation or explain the stereochemical outcome of the reaction. This article comprises several case studies, sorted according to the method used in their study. The aim of this review is to give the investigators an overview of the methods currently utilized for mechanistic investigations in hydrogen-bonding organocatalysis.

  6. Theoretical and experimental study of mixed solvent electrolytes

    International Nuclear Information System (INIS)

    Cummings, P.T.; O'Connell, J.P.

    1990-01-01

    In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

  7. A theoretical study on the optical properties of black silicon

    Science.gov (United States)

    Ma, Shijun; Liu, Shuang; Xu, Qinwei; Xu, Junwen; Lu, Rongguo; Liu, Yong; Zhong, Zhiyong

    2018-03-01

    There is a wide application prospect in black silicon, especially in solar cells and photoelectric detectors. For further optimization of black silicon, it is important to study its optical properties. Especially, the influence of the surface nanostructures on these properties and the light propagation within the nanostructures are relevant. In this paper, two kinds of black silicon models are studied via the finite differences time domain method. The simulated reflectance spectra matches well with the measured curve. Also, the light intensity distribution within the nanostructures shows that near 80% of the incident light are redirected and subjected to internal reflection, which provides powerful support for the good light trapping properties of black silicon.

  8. A Theoretical Study of Subsurface Drainage Model Simulation of ...

    African Journals Online (AJOL)

    A three-dimensional variable-density groundwater flow model, the SEAWAT model, was used to assess the influence of subsurface drain spacing, evapotranspiration and irrigation water quality on salt concentration at the base of the root zone, leaching and drainage in salt affected irrigated land. The study was carried out ...

  9. Theoretical Study of Physiochemical Properties of Insulin-Like Growth

    African Journals Online (AJOL)

    dell

    biological problems, the empirical force fields, have great difficulty in simulating folding of. Insulin-like Growth Factor 1 (IGF-1). In an effort to understand the conformational preferences that may be attributed to stereoelectronic effects, a number of computational studies were carried out. Monte Carlo, Molecular Dynamics and ...

  10. Theoretical Study of Physiochemical Properties of Insulin-like ...

    African Journals Online (AJOL)

    The computational approach to studying structural changes in a wide range of physical and biological problems, the empirical force fields, have great difficulty in simulating folding of Insulin-like Growth Factor 1 (IGF-1). In an effort to understand the conformational preferences that may be attributed to stereoelectronic effects, ...

  11. Theoretical study of the catalytic desulfurization mechanism of ...

    African Journals Online (AJOL)

    The desulfurization process of compounds implicates two steps. The first step is the adsorption process on the catalytic site and the second, the breaking of the carbon-heteroatom bond leading to the heteroatom elimination. The adsorption process of thiiren have been studied and published in previous works. The results ...

  12. Theoretical Study of Spin Crossover in 30 Iron Complexes

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2016-01-01

    Spin crossover was studied in 30 iron complexes using density functional theory to quantify the direction and magnitude of dispersion, relativistic effects, zero-point energies, and vibrational entropy. Remarkably consistent entropy−enthalpy compensation was identified. Zero-point energies favor...

  13. Theoretical study on the molecular and crystal structures of nitrogen ...

    Indian Academy of Sciences (India)

    of NF3 has been improved by a number of workers3–6 and has been patented. Nitrogen trifluoride can also be formed by direct fluorination of ammonia. It is a stable gas with strong oxidizing properties. It can be used as a potential oxidant for spacecraft propulsion. Decades ago, studies on the compound have been made: ...

  14. Connecting theoretical and empirical studies of trait-mediated interactions

    Czech Academy of Sciences Publication Activity Database

    Bolker, B.; Holyoak, M.; Křivan, Vlastimil; Rowe, L.; Schmitz, O.

    2003-01-01

    Roč. 84, č. 5 (2003), s. 1101-1114 ISSN 0012-9658 Institutional research plan: CEZ:AV0Z5007907 Keywords : community models * competition * empirical study Subject RIV: EH - Ecology, Behaviour Impact factor: 3.701, year: 2003

  15. A theoretical parametric study of Water Flooding | Ohirhian | Journal ...

    African Journals Online (AJOL)

    A multidimensional mathematical model derived by combining equation of continuity and Darcy's law and solved using the strongly implicit procedure (SIP) has been used to study the effects of permeability distribution, shape of the relative permeability and capillary pressure curves, ratio of water to oil viscosity, and amount ...

  16. Theoretical studies of the dynamics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, A.F. [Argonne National Laboratory, IL (United States)

    1993-12-01

    Recent research effort has focussed on several reactions pertinent to combustion. The formation of the formyl radical from atomic hydrogen and carbon monoxide, recombination of alkyl radicals and halo-alkyl radicals with halogen atoms, and the thermal dissociation of hydrogen cyanide and acetylene have been studied by modeling. In addition, the inelastic collisions of NCO with helium have been investigated.

  17. Study of B Meson Decays to ppbarh Final States

    Energy Technology Data Exchange (ETDEWEB)

    Hryn' ova, Tetiana B.; /SLAC

    2006-03-22

    B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X

  18. Theoretical study (Lagrangian modeling) of turbulent particulate dispersion

    Science.gov (United States)

    Berlemont, A.; Grancher, M. S.; Desjonqueres, P.

    A study aimed at improving the prediction and knowledge of two phase phenomena in a turbomachine is presented. A code to three dimensionally simulate particle dispersion, taking account of turbulent droplet evaporation, and which can be easily integrated into the DIAMANT code, is developed. Lagrangian modeling of particle dispersion is used. The influence of turbulence on evaporation appears to be non-negligible and must therefore be taken into account in droplet turbulent transfer problems.

  19. A theoretical study on interaction of proline with gold cluster

    Indian Academy of Sciences (India)

    Abstract. Interaction of proline with gold cluster was studied using density functional theory (DFT). Two types of mixed basis sets UB3LYP/6-311++G ∪ LANL2MB and UB3LYP/6-311++G ∪ LANL2DZ were used for optimization of complex structures. Proline interacts with gold cluster either through one anchor bond, N–Au ...

  20. The Case Study Approach: Some Theoretical, Methodological and Applied Considerations

    Science.gov (United States)

    2013-06-01

    studies have a long history of use and account for a large portion of articles and books in various disciplines, such as psychology , sociology...photographs, videotapes, projective techniques and psychological testing, life histories and the like (Stake 1995; Tellis 1997; Yin 2009). Hence, case...Choudrie (2007) examined the behaviours of employees including understanding of the humanistic elements such as meta-abilities (i.e. cognitive skills

  1. Theoretical study of adsorption of lithium atom on carbon nanotube

    OpenAIRE

    Senami, Masato; Ikeda, Yuji; Fukushima, Akinori; Tachibana, Akitomo

    2011-01-01

    We investigate the adsorption of lithium atoms on the surface of the (12, 0) single wall carbon nanotube (SWCNT) by using ab initio quantum chemical calculations. The adsorption of one lithium atom on the inside of this SWCNT is favored compared to the outside. We check this feature by charge transfer and regional chemical potential density. The adsorption of multiple lithium atoms on the interior of the SWCNT is studied in terms of adsorption energy and charge transfer. We show that repulsiv...

  2. Theoretical study on the molecular and crystal structures of nitrogen ...

    Indian Academy of Sciences (India)

    The molecular and crystal structure of the adduct NF3·BF3 was studied computationally using density functional theory. It shows that the adduct exists in the form of a complex but is not ionic. The heats of formation in the gas and the condensed phase of the adduct are −1266.09 and −1276.37 kJ·mol−1, respectively, which ...

  3. Dynamic behavior of hybrid sodium bearings. Theoretical and experimental studies

    International Nuclear Information System (INIS)

    Guidez, J.; Juignet, N.; Queval, M.

    1981-08-01

    The primary sodium pump shaft lower section of a fast breeder reactor is guided by a hydrostatic sodium bearing. This recess type bearing is supplied via orifices restrictors. Sodium is sampled at hight pressure at the diffuser outlet and is then centrifuged towards the orifices restrictors. Bearing stiffness and damping data is essential for the study of rotor dynamic behavior. Two points in particular may then be studied: - calculation of rotor instability ranges and critical speeds, - dynamic behavior of the rotor in the event of an earthquake. As regards the bearing design, the problem is to obtain the pressure fields in the liquid film. The integration of these pressure fields will then give the stiffness coefficients. The damping coefficients can then be obtained by the same calculation after slight displacement. The Reynolds equation can be used to study the liquid film (under any conditions for the turbulent and inertia effects). Then the computer code DELPAL is explained that solves the modified Reynolds equation using a finite element method. The presentation of tests conducted in 1981 on the Super-Phenix 1 full scall bearing (diameter 850 mm) in water is made. In conclusion this paper describes a method for calculating the stiffness and damping matrices of a hydrostatic bearing using the DELPAL calculation code and shows the loop of behavior tests on a bearing with sinusoidal excitation. The results, obtained by calculation and by testing, are indispensable when calculating the dynamic behavior of the shaft line

  4. Comparative theoretical and experimental study on novel tri-quinoline system and its anticancer studies

    Science.gov (United States)

    Gayathri, Kasirajan; Radhika, Ramachandran; Shankar, Ramasamy; Malathi, Mahalingam; Savithiri, Krishnaswamy; Sparkes, Hazel A.; Howard, Judith A. K.; Mohan, Palathurai Subramaniam

    2017-04-01

    A novel compound 2-chloro-3,6-bis-(quinolin-8-yloxymethyl)-quinoline 3 bearing a tri-quinoline moiety has been synthesized from 2-chloro-3,6-dimethyl quinoline 1 and 8-hydroxy quinoline 2 using dry acetone and K2CO3 as a base. 3 has been characterized by using FT-IR, FT-Raman, UV-Vis, 1H NMR, 13C NMR spectra and single crystal X-ray diffraction methods. We have also made a combined experimental and theoretical study on the molecular structure, vibrational spectra, NMR, FT-IR, FT-Raman and UV-Vis spectra of 2-chloro-3,6-bis-(quinolin-8-yloxymethyl)-quinoline. The theoretical studies of the title compound have been evaluated by using density functional theory calculations using B3LYP/6-31+G(d,p) and M06-2X/6-31+G(d,p) level of theories. The calculated theoretical values were found to be in good agreement with the experimental findings. The single crystal structure 3 crystallized in the orthorhombic space group Pna21. The compound 3 exhibits higher cytotoxicity in human cervical cancer cell lines (HeLa) than human breast cancer cell lines (MCF7).

  5. Theoretical and numerical study of cyclotron in space charge conditions

    International Nuclear Information System (INIS)

    Cazoll, V.

    1988-11-01

    During the last decade, the need of high ion beam intensities urged the cyclotron laboratories to amplify the efforts to study the space charge effects in these machines. The cyclotron space charge effects are intimately linked to two specific features of this kind of accelerator; - the beam is formed of a succession of bunches having about the same size for transverse and longitudinal dimensions, - the radial and longitudinal motions are strongly coupled. The analytical model developed in this thesis explains some effects produced by the space charge forces. It describes the motion of an ion contained in a bunch. This ion moves under the effects of the guiding field forces, the accelerator cyclotron field forces and the space charge forces created by the other particles of the bunch. The solutions of the first order differential equations describe the small motion around one particle, which is taken as a reference particle. These solutions are valid in the vicinity of the bunch center, where the space charge forces are considered linear. The results of the model are compared with those obtained from a multiparticle code. This code has been already used successfully at GANIL (the Great National Heavy Ions Accelerator). The evolution of the whole beam has also been studied with this code, which takes into acount the non linear space charge effects and all the couplings. The results obtained by the numerical study of a proposed new injector for the cyclotrons of GANIL shows that it is possible to obtain an important increase of the beam intensity [fr

  6. Theoretical Studies of Optical Properties of Silver Nanoparticles

    International Nuclear Information System (INIS)

    Ye-Wan, Ma; Zhao-Wang, Wu; Li-Hua, Zhang; Jie, Zhang

    2010-01-01

    Optical properties of silver nanoparticles such as extinction, absorption and scattering efficiencies are studied based on Green's function theory. The numerical simulation results show that optical properties of silver nanoparticles are mainly dependent on their sizes and geometries; the localized plasmon resonance peak is red shifted when the dielectric constant of the particle's surrounding medium increases or when a substrate is presented. The influences of wave polarizations, the incident angles of light, the composite silver and multiply-layers on the plasmon resonance are also reported. The numerical simulation of optical spectra is a very useful tool for nanoparticle growth and characterization. (fundamental areas of phenomenology(including applications))

  7. Role of hot electron transport in scintillators: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Huihui [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Lab. of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen Univ. (China); Li, Qi [Physical Sciences Division, IBM TJ Watson Research Center, Yorktown Heights, NY (United States); Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Lu, Xinfu; Williams, R.T. [Department of Physics, Wake Forest University, Winston Salem, NC (United States); Qian, Yiyang [College of Engineering and Applied Science, Nanjing University (China); Wu, Yuntao [Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States)

    2016-10-15

    Despite recent intensive study on scintillators, several fundamental questions on scintillator properties are still unknown. In this work, we use ab-initio calculations to determine the energy dependent group velocity of the hot electrons from the electronic structures of several typical scintillators. Based on the calculated group velocities and optical phonon frequencies, a Monte-Carlo simulation of hot electron transport in scintillators is carried out to calculate the thermalization time and diffusion range in selected scintillators. Our simulations provide physical insights on a recent trend of improved proportionality and light yield from mixed halide scintillators. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. A theoretical study on free monopolar spacial change

    International Nuclear Information System (INIS)

    Camargo, P.C. de.

    1975-01-01

    Assuming planar symmetry and an arbitrary charge distribution that spreads through the sample, the one-carrier free-space-charge motion is studied in insulators solids. Using the method of characteristics we can reduce the problem to the resolution of a system of two ordinary first order differential equations. Results are applied to linear, exponential and S.C.L. current charge distributions, under short-circuit conditions. The charge distribution for several times and the discharge currents are presented. The results are compared with those from an approximated method, based on variational principles. (author) [pt

  9. Theoretical study of adsorption of lithium atom on carbon nanotube

    Directory of Open Access Journals (Sweden)

    Masato Senami

    2011-12-01

    Full Text Available We investigate the adsorption of lithium atoms on the surface of the (12,0 single wall carbon nanotube (SWCNT by using ab initio quantum chemical calculations. The adsorption of one lithium atom on the inside of this SWCNT is favored compared to the outside. We check this feature by charge transfer and regional chemical potential density. The adsorption of multiple lithium atoms on the interior of the SWCNT is studied in terms of adsorption energy and charge transfer. We show that repulsive force between lithium atoms destabilizes a system for the large number of lithium atoms.

  10. Hydroxyl radical induced transformation of phenylurea herbicides: A theoretical study

    International Nuclear Information System (INIS)

    Mile, Viktória; Harsányi, Ildikó; Kovács, Krisztina; Földes, Tamás; Takács, Erzsébet; Wojnárovits, László

    2017-01-01

    Aromatic ring hydroxylation reactions occurring during radiolysis of aqueous solutions are studied on the example of phenylurea herbicides by Density Functional Theory calculations. The effect of the aqueous media is taken into account by using the Solvation Model Based on Density model. Hydroxyl radical adds to the ring because the activation free energies (0.4–47.2 kJ mol −1 ) are low and also the Gibbs free energies have high negative values ((−27.4) to (−5.9) kJ mol −1 ). According to the calculations in most of cases the ortho- and para-addition is preferred in agreement with the experimental results. In these reactions hydroxycyclohexadienyl type radicals form. In a second type reaction, when loss of chlorine atom takes place, OH/Cl substitution occurs without cyclohexadienyl type intermediate. - Highlights: • Attack of • OH to aniline, phenol, fenuron, monuron, diuron was studied by DFT. • Ortho-para directing is suggested with –NH 2 , –OH and –NHCON(CH 3 ) 2 groups. • • OH addition to the ring gives hydroxycyclohexadienyl radical. • Attack at C-Cl leads to • OH/Cl substitution without cyclohexadienyl intermediate.

  11. Structural and theoretical studies of mixed metal oxides

    International Nuclear Information System (INIS)

    Butler, V.

    1982-10-01

    Diffuse neutron scattering studies were made first on powdered samples of uranium/cerium oxide and, secondly, on single crystals of stoichiometric and reduced thorium/cerium oxide. The powder studies show that at low dopant concentrations, the cation distribution is random but, as the dopant concentration increases, considerable short range ordering takes place on the cation sublattice. The presence of oxygen vacancies at high temperature, when the cations are mobile, does not appear to affect the distribution of the cations. Powder neutron diffraction was carried out on stoichiometric and reduced samples of uranium/cerium oxide and, for comparison, on a reduced sample of 20 mole% CeO 2 in ThO 2 . In the former samples, separation of a second phase occurs on reduction of samples containing >= 20 mole% CeO 2 and, at all dopant concentrations, the level of reduction achieved is well below the expected value. The thorium/cerium oxide sample, on the other hand, is single-phase and fully reduced. Calculations performed using computer simulation techniques show that, in doped CeO 2 and ZrO 2 , the radius of the dopant ion is extremely important in determining the magnitude of the dopant-vacancy interaction and hence the ionic conductivity of the material. The results are discussed. (author)

  12. Experimental and theoretical study of cascade solar stills in Iran

    International Nuclear Information System (INIS)

    Tabrizi, F.F.; Sharak, A.Z.

    2009-01-01

    Due to low annual rainfall, most of Iran is dominated by arid and semi-arid areas. The solar radiation intensity is extremely high in most of the country. The need to produce fresh water from brackish water is considerably high, especially in dry regions. Desalination of brackish water may become a competitive potential water resource to meet potable water demand, and as the price of oil goes higher, using solar energy for water desalinisation becomes more economical. This paper presented a study that involved mathematical modeling of the first solar still in Iran. The cumulative fresh water production and water temperature were calculated as a function of time. The obtained results were verified by one month daily-based experimental data. The paper also provided background information on the Koshk village, situated in the south part of Iran near Badar Abbas city. Various investigations regarding meteorological conditions, economical considerations, and technical and operational appropriateness demonstrated that the cascade solar still is suitable for desalination of brackish water. 100 solar stills were installed at the site to provide potable water for a nearby village. It was concluded that the model could be used to simulate and optimize the effective design parameters in future studies. 6 refs., 7 figs

  13. Experimental and theoretical study of deformable mirror actuator arrays

    Science.gov (United States)

    Pilar, Jan; Bonora, Stefano; Lucianetti, Antonio; Jelinkova, Helena; Mocek, Tomas

    2015-01-01

    Deformable mirrors have gained increasing interest in many different fields of application including laser physics, and they are becoming a universal tool for correcting optical aberrations of laser beams especially in large scale laser systems. One of the most common types of deformable mirror is a bimorph design which uses two plates of piezomaterial to which single electrodes are connected. These electrodes form the actuator array and their layout defines the resulting performance of the mirror to some extent. In the end all types of deformable mirrors currently used use an actuator array of some sort. To estimate the significance and effect of different actuator layout and shapes of actuators, an experimental study was performed. Four different commonly used actuator arrays were compared using photo-controlled deformable mirror. Using such device allows to study the effect of actuator layout separately from all other effects, since the device remains the same including all its imperfections. The experimental results are compared with numerical simulations and discussion is presented.

  14. Theoretical study of the luminance distribution on the Venus disk

    International Nuclear Information System (INIS)

    Bigourd, C.; Deuze, J.L.; Devaux, C.; Herman, M.; Lenoble, J.

    1974-01-01

    The analysis of the sunlight scattered by Venus gives some insight upon its clouds. The measurements of polarized light are probably more sensitive to the nature of their constituents, and some recent studies seem to be able to give a satisfactory interpretation of this part of the scattered light. But the polarized light concerns the upper part of the clouds, and it is interesting to compare these with intensity measurements. The phase curves, for the integrated light, leave some indetermination, so we have studied if the intensity distribution on the Venus disk could give more accurate informations. This work based on some plates kindly communicated by A. Dolfus, and analysed at Meudon Observatory, is more a preliminary investigation of the sensitivity of the method than an interpretation of the partial results presented. A simple model, of homogeneous plane parallel cloud, has been used, and the influence of various parameters has been tested (single scattering albedo, refractive index of particles and size distribution, optical depth of the cloud). (Auth.)

  15. Singlet oxygen reactions with flavonoids. A theoretical-experimental study.

    Directory of Open Access Journals (Sweden)

    Javier Morales

    Full Text Available Detection of singlet oxygen emission, λ(max = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, k(T, and the reactive reaction rate constant, k(r, for the reaction between singlet oxygen and several flavonoids. Values of k(T determined in deuterated water, ranging from 2.4×10(7 M(-1 s(-1 to 13.4×10(7 M(-1 s(-1, for rutin and morin, respectively, and the values measured for k(r, ranging from 2.8×10(5 M(-1 s(-1 to 65.7×10(5 M(-1 s(-1 for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid.

  16. Singlet oxygen reactions with flavonoids. A theoretical-experimental study.

    Science.gov (United States)

    Morales, Javier; Günther, Germán; Zanocco, Antonio L; Lemp, Else

    2012-01-01

    Detection of singlet oxygen emission, λ(max) = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, k(T), and the reactive reaction rate constant, k(r), for the reaction between singlet oxygen and several flavonoids. Values of k(T) determined in deuterated water, ranging from 2.4×10(7) M(-1) s(-1) to 13.4×10(7) M(-1) s(-1), for rutin and morin, respectively, and the values measured for k(r), ranging from 2.8×10(5) M(-1) s(-1) to 65.7×10(5) M(-1) s(-1) for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid.

  17. Theoretical study of the crossover into hydrodynamic regime in graphene

    Science.gov (United States)

    Ho, Derek; Yudhistira, Indra; Hu, Ben Yu-Kuang; Adam, Shaffique

    Experiments on graphene have recently succeeded in entering the hydrodynamic regime, as demonstrated by successful observations of strong violation of Wiedemann-Franz law, the Gurzhi effect and electronic Poiseuille flow. It is known that electronic systems enter the hydrodynamic regime when electron-electron scattering dominates over electron-impurity and electron-phonon scattering. However, a quantitative study of this transition from the Fermi liquid to hydrodynamic regime is still lacking. In view of this, we quantitatively analyze the electron-electron, electron-impurity and electron-phonon scattering rates as a function of temperature, charge doping and disorder (charge puddle) strength. This yields a quantitative understanding of the onset of hydrodynamic electronic behavior in graphene samples. This work is supported by the National Research Foundation of Singapore under its Fellowship program (NRF-NRFF2012-01) and by the Singapore Ministry of Education and Yale-NUS College through Grant No. R-607-265-01312.

  18. Theoretical study of lithium clusters by electronic stress tensor

    International Nuclear Information System (INIS)

    Ichikawa, Kazuhide; Nozaki, Hiroo; Komazawa, Naoya; Tachibana, Akitomo

    2012-01-01

    We study the electronic structure of small lithium clusters Li n (n = 2 ∼ 8) using the electronic stress tensor. We find that the three eigenvalues of the electronic stress tensor of the Li clusters are negative and degenerate, just like the stress tensor of liquid. This leads us to propose that we may characterize a metallic bond in terms of the electronic stress tensor. Our proposal is that in addition to the negativity of the three eigenvalues of the electronic stress tensor, their degeneracy characterizes some aspects of the metallic nature of chemical bonding. To quantify the degree of degeneracy, we use the differential eigenvalues of the electronic stress tensor. By comparing the Li clusters and hydrocarbon molecules, we show that the sign of the largest eigenvalue and the differential eigenvalues could be useful indices to evaluate the metallicity or covalency of a chemical bond.

  19. A theoretical-experimental study of backup bearings

    DEFF Research Database (Denmark)

    Lampe Linhares da Fonseca, Cesar Augusto

    The backup bearing is a mechanical component designed to improve the safety and reliability of Active Magnetic Bearings (AMBs). Rotors levitated by AMBs can be subjected to delevitation and consequently to impacts if a power loss happens because real-time active control is necessary to keep them...... running. When impacting on a stator surface, the rotor can develop a dangerous behavior caused by the friction force known as the full annular backward whirl. In this situation, the rotor will describe a trajectory around the surface of the bearing at a dominant superharmonic frequency and with large...... radial forces. Remaining in this condition, it may lead to permanent damage or total failure of the machine. This is why the backup bearing design has to be carefully planned and investigated as to whether it helps to protect the integrity of the machine. This PhD thesis provides a comprehensive study...

  20. Exergy performance of different space heating systems: A theoretical study

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Three space heating systems (floor heating with different floor covering resistances, radiator heating with different working temperatures, warm-air heating with and without heat recovery) were compared using a natural gas fired condensing boiler as the heat source. For the floor heating systems......, the effects of floor covering resistance on the whole system performance were studied using two heat sources; a natural gas fired condensing boiler and an air-source heat pump. The heating systems were also compared in terms of auxiliary exergy use for pumps and fans. The low temperature floor heating system...... performed better than other systems in terms of exergy demand. The use of boiler as a heat source for a low-exergy floor heating system creates a mismatch in the exergy supply and demand. Although an air-source heat pump could be a better heat source, this depends on the origin of the electricity supplied...

  1. Theoretical Study of Watershed Eco-Compensation Standards

    Science.gov (United States)

    Yan, Dandan; Fu, Yicheng; Liu, Biu; Sha, Jinxia

    2018-01-01

    Watershed eco-compensation is an effective way to solve conflicts over water allocation and ecological destruction problems in the exploitation of water resources. Despite an increasing interest in the topic, the researches has neglected the effect of water quality and lacked systematic calculation method. In this study we reviewed and analyzed the current literature and proposedatheoretical framework to improve the calculation of co-compensation standard.Considering the perspectives of the river ecosystems, forest ecosystems and wetland ecosystems, the benefit compensation standard was determined by the input-output corresponding relationship. Based on the opportunity costs related to limiting development and water conservation loss, the eco-compensation standard was calculated.In order to eliminate the defects of eco-compensation implementation, the improvement suggestions were proposed for the compensation standard calculation and implementation.

  2. Hydrogen detection by a boron sheet: A theoretical study .

    Science.gov (United States)

    Dominguez, F. Javier; Novotny, Michal; Krstic, Predrag S.

    A single boron sheet is now considered as a new nanomaterial with promising applications in electronics and as a sensor device. In this study we present quantum-classical molecular dynamic (QCMD) calculation of reflection, adsorption, and transmission processes of hydrogen impacting at energy in range 0.25 to 100 eV on a single boron sheet. Quantum-mechanical component of our QCMD approach is self-consistent charge tight binding density functional theory method (SCC-DFTB,). We consider the corrugated boron sheet as our target, created experimentally, and compare our results with those reported for graphene, showing noticeable differences. Research supported by CONACyT postdoctoral scholarship to FJD and the Fulbright Comission (Grant 15160939) to MN. Results were obtained using the LI-red cluster at IACS.

  3. Hydroxyl radical induced transformation of phenylurea herbicides: A theoretical study

    Science.gov (United States)

    Mile, Viktória; Harsányi, Ildikó; Kovács, Krisztina; Földes, Tamás; Takács, Erzsébet; Wojnárovits, László

    2017-03-01

    Aromatic ring hydroxylation reactions occurring during radiolysis of aqueous solutions are studied on the example of phenylurea herbicides by Density Functional Theory calculations. The effect of the aqueous media is taken into account by using the Solvation Model Based on Density model. Hydroxyl radical adds to the ring because the activation free energies (0.4-47.2 kJ mol-1) are low and also the Gibbs free energies have high negative values ((-27.4) to (-5.9) kJ mol-1). According to the calculations in most of cases the ortho- and para-addition is preferred in agreement with the experimental results. In these reactions hydroxycyclohexadienyl type radicals form. In a second type reaction, when loss of chlorine atom takes place, OH/Cl substitution occurs without cyclohexadienyl type intermediate.

  4. 1,2-Propanediol. Comprehensive experimental and theoretical study

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Nell, Gernot

    2009-01-01

    The standard (p 0 =0.1MPa) molar enthalpy of formation at the temperature 298.15 K of the liquid 1,2-propanediol was measured using combustion calorimetry. Molar enthalpies of vaporization of isomeric 1,2-propanediols were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. Thermochemical investigations of 1,2-ethanediol and 1,2-propanediol available in the literature were collected and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available sublimation enthalpies data and to recommend consistent and reliable set of vaporization and formation enthalpies for both diols under study. Ab initio calculations of gaseous molar enthalpy of formation of 1,2-ethanediol and 1,2-propanediol have been performed using the G3MP2 method and results are in excellent agreement with the selected experimental data.

  5. Theoretical Study of Sodium-Water Surface Reaction Mechanism

    Science.gov (United States)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki; Hashimoto, Kenro

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using the ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule on the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. It was found that the estimated rate constant of the former was much larger than the latter. The results are the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by Japan Atomic Energy Agency (JAEA) toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR).

  6. Theoretical study of sodium-water surface reaction mechanism

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki; Hashimoto, Kenro

    2012-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using the ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule on the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. It was found that the estimated rate constant of the former was much larger than the latter. The results are the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by Japan Atomic Energy Agency (JAEA) toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  7. Chemical functionalization of graphene via aryne cycloaddition: a theoretical study.

    Science.gov (United States)

    Zhao, Jing-xiang; Wang, Hong-xia; Gao, Bo; Wang, Xiao-guang; Cai, Qing-hai; Wang, Xuan-zhang

    2012-06-01

    Chemical functionalization of graphene provides a promising route to improve its solubility in water and organic solvents as well as modify its electronic properties, thus significantly expanding its potential applications. In this article, by using density functional theory (DFT) methods, we have studied the effects of the chemical functionalization of graphenes via aryne cycloaddition on its properties. We found that the adsorption of an isolated aryne group on the graphene sheet is very weak with the adsorption energy of -0.204 eV, even though two new single C-C interactions are formed between the aryne group and the graphene. However, the interaction of graphene with the aryne group can be greatly strengthened by (i) substituting the H-atoms in aryne group with F-, Cl-, -NO(2) (electron-withdrawing capability), or CH(3)-group (electron-donating capability), and (ii) increasing the coverage of the adsorbed aryne groups on the graphene sheet. As expected, the strongest bonding is found on the graphene edges, in which the adsorbed aryne groups prefer to be far away from each other. Interestingly, chemical functionalization with aryne groups leads to an opening of the band gap of graphene, which is dependent on the coverage of the adsorbed aryne groups. The present work provides an insight into the modifications of graphene with aryne groups in experiment.

  8. Theoretical study of spin Hall effect in conjugated Organic semiconductors

    Science.gov (United States)

    Mahani, M. R.; Delin, A.

    The spin Hall effect (SHE), a direct conversion between electronic and spin currents, is a rapidly growing branch of spintronics. The study of SHE in conjugated polymers has gained momentum recently due to the weak spin-orbit couplings and hyperfine interactions in these materials. Our calculations of SHE based on the recent work, are the result of the misalignment of pi-orbitals in triads consisting of three molecules. In disordered organics, where the electronic conduction is through hopping of the electrons among randomly oriented molecules, instead of identifying a hopping triad to represent the entire system, we numerically solve the master equations for electrical and spin hall conductivities by summing the contributions from all triads in a sufficiently large system. The interference between the direct and indirect hoppings in these triads leads to SHE proportional to the orientation vector of molecule at the first order of spin-orbit coupling. Hence, our results show, the degree of molecular alignment as well as the strength of the spin-orbit coupling can be used to control the SHE in organics.

  9. Theoretical study for the interlamellar aminoalcohol functionalization of kaolinite

    International Nuclear Information System (INIS)

    Hou, Xin-Juan; Li, Huiquan; Liu, Qinfu; Cheng, Hongfei; He, Peng; Li, Shaopeng

    2015-01-01

    Graphical abstract: - Highlights: • The results indicated that aminoalcohols exist with a mixing of intercalation and grafting. • Aminoalcohols can form strong hydrogen bonds with Al octahedral sheet. • The interaction between aminoalcohols and Si tetrahedral sheet are mainly attributed by vdW force. • Aminoalcohols grafting or intercalating on kaolinite have strong reactivity as electron donors. - Abstract: Fundamental problems related to aminoalcohols intercalating on kaolinite were investigated by using density functional theory method. This study examines the adsorption modes of diethanolamine and triethanolamine on kaolinite, the role of hydrogen bonds and van der Waals (vdW) forces between aminoalcohols and interlayer of kaolinite, and the change of molecular orbital occupancies of functionalized kaolinite. Results show that functionalized kaolinite is physically intercalated and covalently grafted by aminoalcohols. Non-covalent interaction analysis provides a visualized description that intercalated aminoalcohols form strong hydrogen bonds with Al octahedral sheet, and the interaction between aminoalcohols and Si tetrahedral sheet is mainly attributed to weak vdW force. The analysis of molecular orbital occupancies for kaolinite complex showed that the functionalized kaolinite has strong chemical reactivity as electron donors on the sites of grafted or intercalated aminoalcohols for further chemical reaction with other materials

  10. Theoretical and numerical study of heat transfer deterioration in HPLWR

    International Nuclear Information System (INIS)

    Palko, D.; Anglart, H.

    2007-01-01

    A numerical investigation of the Heat Transfer Deterioration (HTD) phenomena is performed using the low-Re k - ω turbulence model. Steady state Reynolds-averaged Navier-Stokes equations are solved together with equations for the transport of enthalpy and turbulence. Equations are solved for the supercritical water flow at different pressures, using water properties from the standard IAPWS tables. All cases are extensively validated against experimental data. The influence of buoyancy on the HTD is demonstrated for different mass flow rates in the heated pipes. Numerical results prove that the RANS low-Re turbulence modeling approach is fully capable to simulate the heat transfer in pipes with the water flow at supercritical pressures. A study of buoyancy influence shows that for the low mass flow rates of coolant, the influence of buoyancy forces on the heat transfer in heated pipes is significant. For the high flow rates, buoyancy influence could be neglected and there are clearly other mechanisms causing the decrease in heat transfer at high coolant flow rates. (author)

  11. Theoretical study of bismuth-doped cadmium telluride

    Science.gov (United States)

    Menendez-Proupin, E.; Rios-Gonzalez, J. A.; Pena, J. L.

    Cadmium telluride heavily doped with bismuth has been proposed as an absorber with an intermediate band for solar cells. Increase in the photocurrent has been shown recently, although the overall cell efficiency has not improved. In this work, we study the electronic structure and the formation energies of the defects associated to bismuth impurities. We have performed electronic structure calculations within generalized density functional theory, using the exchange-correlation functional HSE(w) , where the range-separation parameter w has been tuned to reproduce the CdTe bandgap. Improving upon previous reports, we have included the spin-orbit interaction, which modifies the structure of the valence band and the energy levels of bismuth. We have found that interstitial Bi (Bii) tends to occupy Cd vacancies, cadmium substitution (BiCd) creates single donor level, while tellurium substitution (BiTe) is a shallow single acceptor. We investigate the interaction between these point defects and how can they be combined to create a partially filled intermediate band. Supported by FONDECYT Grant 1130437, CONACYT-SENER SUSTENTABILIDAD ENERGETICA/project CeMIE-Sol PY-207450/25 and PY-207450/26. JARG acknowledges CONACYT fellowship for research visit. Powered@NLHPC (ECM-02).

  12. Theoretical study for the interlamellar aminoalcohol functionalization of kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xin-Juan [Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Li, Huiquan, E-mail: hqli@home.ipe.ac.cn [Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Qinfu; Cheng, Hongfei [School of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083 (China); He, Peng; Li, Shaopeng [Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-08-30

    Graphical abstract: - Highlights: • The results indicated that aminoalcohols exist with a mixing of intercalation and grafting. • Aminoalcohols can form strong hydrogen bonds with Al octahedral sheet. • The interaction between aminoalcohols and Si tetrahedral sheet are mainly attributed by vdW force. • Aminoalcohols grafting or intercalating on kaolinite have strong reactivity as electron donors. - Abstract: Fundamental problems related to aminoalcohols intercalating on kaolinite were investigated by using density functional theory method. This study examines the adsorption modes of diethanolamine and triethanolamine on kaolinite, the role of hydrogen bonds and van der Waals (vdW) forces between aminoalcohols and interlayer of kaolinite, and the change of molecular orbital occupancies of functionalized kaolinite. Results show that functionalized kaolinite is physically intercalated and covalently grafted by aminoalcohols. Non-covalent interaction analysis provides a visualized description that intercalated aminoalcohols form strong hydrogen bonds with Al octahedral sheet, and the interaction between aminoalcohols and Si tetrahedral sheet is mainly attributed to weak vdW force. The analysis of molecular orbital occupancies for kaolinite complex showed that the functionalized kaolinite has strong chemical reactivity as electron donors on the sites of grafted or intercalated aminoalcohols for further chemical reaction with other materials.

  13. Theoretical study of the relativistic molecular rotational g-tensor

    International Nuclear Information System (INIS)

    Aucar, I. Agustín; Gomez, Sergio S.; Giribet, Claudia G.; Ruiz de Azúa, Martín C.

    2014-01-01

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH + (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH + systems. Only for the sixth-row Rn atom a significant deviation of this relation is found

  14. Theoretical study of the relativistic molecular rotational g-tensor

    Energy Technology Data Exchange (ETDEWEB)

    Aucar, I. Agustín, E-mail: agustin.aucar@conicet.gov.ar; Gomez, Sergio S., E-mail: ssgomez@exa.unne.edu.ar [Institute for Modeling and Technological Innovation, IMIT (CONICET-UNNE) and Faculty of Exact and Natural Sciences, Northeastern University of Argentina, Avenida Libertad 5400, W3404AAS Corrientes (Argentina); Giribet, Claudia G.; Ruiz de Azúa, Martín C. [Physics Department, Faculty of Exact and Natural Sciences, University of Buenos Aires and IFIBA CONICET, Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina)

    2014-11-21

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH{sup +} (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH{sup +} systems. Only for the sixth-row Rn atom a significant deviation of this relation is found.

  15. Enhanced piezoelectricity of monolayer phosphorene oxides: a theoretical study.

    Science.gov (United States)

    Yin, Huabing; Zheng, Guang-Ping; Gao, Jingwei; Wang, Yuanxu; Ma, Yuchen

    2017-10-18

    Two-dimensional (2D) piezoelectric materials have potential applications in miniaturized sensors and energy conversion devices. In this work, using first-principles simulations at different scales, we systematically study the electronic structures and piezoelectricity of a series of 2D monolayer phosphorene oxides (POs). Our calculations show that the monolayer POs have tunable band gaps along with remarkable piezoelectric properties. The calculated piezoelectric coefficient d 11 of 54 pm V -1 in POs is much larger than those of 2D transition metal dichalcogenide monolayers and the widely used bulk α-quartz and AlN, and almost reaches the level of the piezoelectric effect in recently discovered 2D GeS. Furthermore, two other considerable piezoelectric coefficients, i.e., d 31 and d 26 with values of -10 pm V -1 and 21 pm V -1 , respectively, are predicted in some monolayer POs. We also examine the correlation between the piezoelectric coefficients and energy stability. The enhancement of piezoelectricity for monolayer phosphorene by oxidation will broaden the applications of phosphorene and phosphorene derivatives in nano-sized electronic and piezotronic devices.

  16. Thermochemical study of cyanopyrazines: Experimental and theoretical approaches

    International Nuclear Information System (INIS)

    Miranda, Margarida S.; Morais, Victor M.F.; Matos, M. Agostinha R.

    2006-01-01

    The standard (p - bar =0.1MPa) molar energy of combustion, at T=298.15K, of crystalline 2,3-dicyanopyrazine was measured by static bomb calorimetry, in oxygen atmosphere. The standard molar enthalpy of sublimation, at T=298.15K, was obtained by Calvet Microcalorimetry, allowing the calculation of the standard molar enthalpy of formation of the compound, in the gas phase, at T=298.15K: Δ f H m - bar (g)=(518.7+/-3.4)kJ.mol -1 . In addition, the geometries of all cyanopyrazines were obtained using density functional theory with the B3LYP functional and two basis sets: 6-31G* and 6-311G**. These calculations were then used for a better understanding of the relation between structure and energetics of the cyanopyrazine systems. These calculations also reproduce measured standard molar enthalpies of formation with some accuracy and do provide estimates of this thermochemical parameter for those compounds that could not be studied experimentally, namely the tri- and tetracyanopyrazines: the strong electron withdrawing cyano group on the pyrazine ring makes cyanopyrazines highly destabilized compounds

  17. Wave-Created Mud Suspensions: A Theoretical Study

    Directory of Open Access Journals (Sweden)

    Jochen Kämpf

    2018-03-01

    Full Text Available We studied wave-created high-density mud suspensions (fluid mud using a one-dimensional water column (1DV model that includes k-ε turbulence closure at a high vertical resolution with a vertical grid spacing of 1 mm. The k-ε turbulence model includes two sediment-related dissipation terms associated with vertical density stratification and viscous drag of flows around sediment particles. To this end, the calibrated model reproduces the key characteristics (maximum concentration and thickness of fluid mud layers created in laboratory experiments over a large range of wave velocities from 10 to 55 cm/s. The findings demonstrate that the equilibrium near-bed mud concentration, Cb, is solely determined from the balance between erosion and deposition fluxes, whereas the thickness of the fluid mud layer is mainly controlled by sediment-induced density stratification, which dissipates turbulence and hence eliminates turbulent sediment diffusivity at the top of the fluid mud layer, the lutocline. Our model stands in contrast to those that suggest that upward sediment diffusion is close to zero at the interface between the fluid mud layer and the overlying fluid. Instead, our model suggests that the upward diffusive flux of fluid mud flows peak at the lutocline and is compensated for enhanced settling fluxes just above it. Our model findings also support the existence of the gelling-ignition process, which is critical for the development of fluid mud beds in modern sedimentary environments.

  18. Theoretical Study of Ethylene Oligomerization by an Organometallic Nickel Catalyst.

    Science.gov (United States)

    Fan, L.; Krzywicki, A.; Somogyvari, A.; Ziegler, T.

    1996-06-19

    The mechanism for ethylene oligomerization by (acac)NiH has been studied using density functional theory (DFT). The transition states for chain propagation and chain termination were optimized and the related reaction barriers calculated. Several possible mechanisms were considered for the chain termination step. Chain termination by beta-hydrogen elimination was found to be energetically unfavorable, and is not likely to be important. Instead, beta-hydrogen transfer to the incoming ethylene unit seems to be operative. The most favorable beta-hydrogen transfer pathway has two transition states. The first leads from a weak pi-complex between an incoming ethylene unit and (acac)NiCH(2)CH(2)R to an intermediate in which the two olefins C(2)H(4) and H(2)CCHR both are strongly pi-complexed to the nickel hydride (acac)NiH. The second barrier takes the intermediate to another weak pi-complex between (acac)NiCH(2)CH(3) and H(2)C=CHR from which the oligomer H(2)C=CHR can be released and the catalyst (acac)NiCH(2)CH(3) regenerated. Due to the mechanism of chain termination, the actual catalyst is proposed to be (acac)NiCH(2)CH(3) whereas (acac)NiH serves as a precursor or precatalyst.

  19. Benchmark thermodynamic properties of methylanisoles: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Emel’yanenko, Vladimir N.; Zaitseva, Ksenia V.; Agapito, Filipe; Martinho Simões, José A.; Verevkin, Sergey P.

    2015-01-01

    Highlights: • Thermochemistry of 2-, 3-, and 4-methylanisoles was studied. • Liquid state enthalpies of formation were measured by calorimetry. • Vaporisation enthalpies were derived from by transpiration method. • Ab initio enthalpies of formation are in excellent agreement with experiment. • A new paradigm for obtaining thermochemistry of liquid compounds was suggested. - Abstract: Accurate standard molar enthalpy of formation values in the liquid phase can be obtained by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporisation. The procedure is illustrated for 2-, 3-, and 4-methyl-anisoles. Using the W1-F12 and G4 quantum-chemical methods, the gas-phase enthalpies of formation of these compounds at T = 298.15 K were computed. Molar enthalpies of vaporisation for these isomers were measured by the transpiration method. Combining the experimental and the high-level ab initio values, the standard molar enthalpies of formation in the liquid phase for all three isomers were derived and compared with those determined for 2- and 4-methyl-anisoles by using combustion calorimetry

  20. A theoretical study on vomitoxin and its tautomers

    Energy Technology Data Exchange (ETDEWEB)

    Tuerker, Lemi [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey)], E-mail: lturker@metu.edu.tr; Guemues, Selcuk [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey); Yuezuencue Yil Universitesi, Kimya Boeluemue, 65080 Kampues, Van (Turkey)

    2009-04-15

    In the present work, the structural and electronic properties of vomitoxin (deoxynivalenol, a mycotoxin) and all of its possible tautomers have been investigated by the application of B3LYP/6-31G(d,p) type quantum chemical calculations. According to the results of the calculations, tautomer V{sub 4} has been found to be the most stable one among all the structures both in the gas and aqueous phases. The calculations also indicated that, vomitoxin and V{sub 2} possess the deepest and the highest lying HOMO levels, respectively. Hence, V{sub 2} is to be more susceptible to oxidations than the others. On the other hand, V{sub 5}(S) and vomitoxin have the lowest and the next lowest LUMO energies, respectively. Whereas, V{sub 1} and V{sub 2} possess quite highly lying (within the group) LUMO energy levels which result in comparatively unfavorable reduction potentials. Some important geometrical and physicochemical properties and the calculated IR spectra of the systems have also been reported in the study.

  1. Theoretical and experimental studies on emissions from wood combustion

    Energy Technology Data Exchange (ETDEWEB)

    Skreiberg, Oeyvind

    1997-12-31

    This thesis discusses experiments on emissions from wood log combustion and single wood particle combustion, both caused by incomplete combustion and emissions of nitric and nitrous oxide, together with empirical and kinetic NO{sub x} modelling. Experiments were performed in three different wood stoves: a traditional stove, a staged air stove and a stove equipped with a catalytic afterburner. Ideally, biomass fuel does not give a net contribution to the greenhouse effect. However, incomplete combustion was found to result in significant greenhouse gas emissions. Empirical modelling showed the excess air ratio and the combustion chamber temperature to be the most important input variables controlling the total fuel-N to NO{sub x} conversion factor. As the result of an international round robin test of a wood stove equipped with a catalytic afterburner, particle emission measurements were found to be the best method to evaluate the environmental acceptability of the tested stove, since the particle emission level was least dependent of the national standards, test procedures and calculation procedures used. In batch single wood particle combustion experiments on an electrically heated small-scale fixed bed reactor the fuel-N to NO conversion factor varied between 0.11-0.86 depending on wood species and operating conditions. A parameter study and homogeneous kinetic modelling on a plug flow reactor showed that, depending on the combustion compliance in question, there is an optimum combination of primary excess air ratio, temperature and residence time that gives a maximum conversion of fuel-N to N{sub 2}. 70 refs., 100 figs., 26 tabs.

  2. Absorption heat cycles. An experimental and theoretical study

    International Nuclear Information System (INIS)

    Abrahamsson, K.

    1993-09-01

    A flow sheeting programme, SHPUMP, was developed for simulating different absorption heat cycles. The programme consists of ten different modules which allow the user to construct his own absorption cycle. The ten modules configurate evaporators, absorbers, generators, rectifiers, condensers, solution heat exchangers, pumps, valves, mixers and splitters. Seven basic and well established absorption cycles are available in the configuration data base of the programme. A new Carnot model is proposed heat cycles. Together with exergy analysis, general equations for the Carnot coefficient of performance and equations for thermodynamic efficiency, exergetic efficiency and exergy index, are derived, discussed and compared for both absorption heat pumps and absorption heat transformers. Utilizing SHPUMP, simulation results are presented for different configurations where absorption heat cycles are suggested to be incorporated in three different unit operations within both pulp and paper and oleochemical industries. One of the application studies reveled that an absorption heat transformer incorporated with an evaporation plant in a major pulp and paper industry, would save 18% of the total prime energy consumption in one of the evaporation plants. It was also concluded that installing an absorption heat pump in a paper drying plant would result in steam savings equivalent to 12 MW. An experimental absorption heat transformer unit operating with self-circulation has been modified and thoroughly tested. A reference heat transformer plant has been designed and installed in a major pulp and paper mill where it is directly incorporated with one of the evaporation plants. Preliminary plant operation data are presented. 72 refs, 63 figs, 33 tabs

  3. Theoretical Study of Amplitude Modulation Application during Radio Frequency Electrocoagulation

    Directory of Open Access Journals (Sweden)

    V. A. Karpuhin

    2015-01-01

    Full Text Available This article concerns the investigation results of influence of the amplitude-modulated acting signal parameters on the thermoelectric characteristics of biological tissues for a specified geometry of the working electrode section during RF mono-polar electrocoagulation. The geometric model ‘electrode - a biological tissue’ was suggested to study the distribution of power and temperature fields in biological tissue during mono-polar coagulation. The model of biological tissue is represented as a cylinder and the needle electrode is an ellipsoid immersed in the biological tissue. The heat and quasi-electrostatics equations are used as a mathematical model. These equations are solved in Comsol Multiphysics environment.As a result, we have got the following findings: the technique of calculating parameters of the PAM acting signal which has a fixed carrier frequency for the needle electrode of a specified geometry and the immersion depth in biological tissues is suggested. Parameters of PAM signal are determined for this electrode geometry. These parameters provide a 60 ... 80°C heating range of biological tissues near the working part of the tool for different amplitudes of acting signal during RF coagulation. It has been found out that both the temperature and the relaxation frequency of biological tissue depend on exposure time for the needle electrode of a specified geometry and immersion depth of the working part of tool into biological tissue.It is shown that the relaxation frequency of the biological tissue, subjected to the radiofrequency pulses, linearly depends on its heating temperature and can be used as a numerical criterion for maintaining the specified temperature conditions. It is found that the relaxation frequency of the biological tissue depends on the contact area of the tool working part and biological tissues. To reduce this dependence it is necessary to provide automatic current control of the output action.

  4. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    1992-05-01

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e + e - problem and heavy ion dynamics

  5. Theoretical study of the infrared frequencies of crystalline methyl acetate under interstellar medium conditions.

    Science.gov (United States)

    Narayanan, Radhika; Inomata, Kensuke; Gopakumar, Geetha; Sivaraman, Bhalamurugan; Zempo, Yasunari; Hada, Masahiko

    2016-01-15

    Identification of methyl acetate in the interstellar medium (ISM) and its spectroscopic studies have prompted us to investigate the structure of crystalline methyl acetate using numerical calculations. Here, we present a theoretical study of the structure of crystalline methyl acetate and its isotopologues and compare the calculated infrared (IR) spectra with the available experimental data. The optimized structure and vibrational properties were calculated using SIESTA software at 0 K. In the optimization process, the Perdew-Burke-Ernzerhof functional and conjugate gradient methods were used with double zeta polarization basis functions. After optimization of the periodic structure, the vibrational frequencies and normal modes were calculated within the harmonic approximation. Using the calculated results, we refine the mode assignments of experimental work on crystalline methyl acetate and determine the low frequency modes (below 650 cm(-1)). To investigate the accuracy of the pseudopotential and confirm the IR frequencies, we performed molecular calculations using a periodic model of methyl acetate and its isotopologues using SIESTA and compared them with results obtained from Gaussian 09 (all electron method) calculations. Finally, we assigned the vibrational modes of crystalline CD3-COO-CH3 and CH3-COO-CD3, for which experimental data are not available in the crystalline phase under ISM conditions. For all of the calculation methods, the IR vibrational modes of molecular and crystalline methyl acetate and its isotopologues were in good agreement with the available experimental data and predict the unavailable values. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Experimental and Theoretical Study of Microturbine-Based BCHP System

    International Nuclear Information System (INIS)

    Fairchild, P.D.

    2001-01-01

    On-site and near-site distributed power generation (DG), as part of a Buildings Cooling, Heating and Power (BCHP) system, brings both electricity and waste heat from the DG sources closer to the end user's electric and thermal loads. Consequently, the waste heat can be used as input power for heat-activated air conditioners, chillers, and desiccant dehumidification systems; to generate steam for space heating; or to provide hot water for laundry, kitchen, cleaning services and/or rest rooms. By making use of what is normally waste heat, BCHP systems meet a building's electrical and thermal loads with a lower input of fossil fuel, yielding resource efficiencies of 40 to 70% or more. To ensure the success of BCHP systems, interactions of a DG system-such as a microturbine and thermal heat recovery units under steady-state modes of operation with various exhaust back pressures-must be considered. This article studies the performance and emissions of a 30-kW microturbine over a range of design and off-design conditions in steady-state operating mode with various back pressures. In parallel with the experimental part of the project, a BCHP mathematical model was developed describing basic thermodynamic and hydraulic processes in the system, heat and material balances, and the relationship of the balances. to the system configuration. The model can determine the efficiency of energy conversion both for an individual microturbine unit and for the entire BCHP system for various system configurations and external loads. Based on actual data Tom a 30-kW microturbine, linear analysis was used to obtain an analytical relationship between the changes in the thermodynamic and hydraulic parameters of the system. The actual data show that, when the backpressure at the microturbine exhaust outlet is increased to the maximum of 7 in. WC (0.017 atm), the microturbine's useful power output decreases by from 3.5% at a full power setting of 30 kW to 5.5% at a one-third power setting (10

  7. Theoretical studies of growth processes and electronic properties of nanostructures on surfaces

    Science.gov (United States)

    Mo, Yina

    Low dimensional nanostructures have been of particular interest because of their potential applications in both theoretical studies and industrial use. Although great efforts have been put into obtaining better understanding of the formation and properties of these materials, many questions still remain unanswered. This thesis work has focused on theoretical studies of (1) the growth processes of magnetic nanowires on transition-metal surfaces, (2) the dynamics of pentacene thin-film growth and island structures on inert surfaces, and (3) our proposal of a new type of semiconducting nanotube. In the first study, we elucidated a novel and intriguing kinetic pathway for the formation of Fe nanowires on the upper edge of a monatomic-layer-high step on Cu(111) using first-principles calculations. The identification of a hidden fundamental Fe basal line within the Cu steps prior to the formation of the apparent upper step edge Fe wire produces a totally different view of step-decorating wire structures and offers new possibilities for the study of the properties of these wires. Subsequent experiments with scanning tunneling microscopy unambiguously established the essential role of embedded Fe atoms as precursors to monatomic wire growth. A more general study of adatom behavior near transition-metal step edges illustrated a systematic trend in the adatom energetics and kinetics, resulted from the electronic interactions between the adatom and the surfaces. This work opens the possibility of controlled manufacturing of one-dimensional nanowires. In the second study, we investigated pentacene thin-films on H-diamond, H-silica and OH-silica surfaces via force field molecular dynamics simulations. Pentacene island structures on these surfaces were identified and found to have a 90-degree rotation relative to the structure proposed by some experimental groups. Our work may facilitate the design and control of experimental pentacene thin-film growth, and thus the development

  8. Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray (Final Report)

    Science.gov (United States)

    EPA announced the release of the final report, Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray. This report represents a case study of engineered nanoscale silver (nano-Ag), focusing on the specific example of nano-Ag as possibly used in disinfectant spr...

  9. Theoretical and numerical study of the equations of Vlasov-Maxwell in the covariant formalism

    International Nuclear Information System (INIS)

    Back, A.

    2011-11-01

    A new point of view is proposed for the simulation of plasmas using the kinetic model which links the equations of Vlasov for the distribution of particles and the equations of Maxwell for the electromagnetic contribution of fields. We use the following principle: the equations of Physics are mathematical objects which put in relation geometrical objects. To preserve the geometrical properties of the various objects in an equation, we use, for the theoretical and numerical study, the differential geometry. All the equations of Physics can be written with differential forms and this point of view is not dependent on the choice of coordinates. We propose then a discretization of the differential forms by using B-Splines. To be coherent with the theory, we also propose a discretization of the various operations of the differential geometry. We test our scheme, first on the equations of Maxwell with several boundary conditions and since it does not depend on the system of coordinates, we also test it when we change coordinates. Finally, we apply the same method to the equations of Vlasov-Poisson in one-dimension and we propose several numerical schemes. (author)

  10. High frequency stimulation of cardiac myocytes: A theoretical and computational study

    Science.gov (United States)

    Weinberg, Seth H.

    2014-12-01

    High-frequency stimulation (HFS) has recently been identified as a novel approach for terminating life-threatening cardiac arrhythmias. HFS elevates myocyte membrane potential and blocks electrical conduction for the duration of the stimulus. However, low amplitude HFS can induce rapidly firing action potentials, which may reinitiate an arrhythmia. The cellular level mechanisms underlying HFS-induced electrical activity are not well understood. Using a multiscale method, we show that a minimal myocyte model qualitatively reproduces the influence of HFS on cardiac electrical activity. Theoretical analysis and simulations suggest that persistent activation and de-inactivation of ionic currents, in particular a fast inward window current, underlie HFS-induced action potentials and membrane potential elevation, providing hypotheses for future experiments. We derive analytical expressions to describe how HFS modifies ionic current amplitude and gating dynamics. We show how fast inward current parameters influence the parameter regimes for HFS-induced electrical activity, demonstrating how the efficacy of HFS as a therapy for terminating arrhythmias may depend on the presence of pathological conditions or pharmacological treatments. Finally, we demonstrate that HFS terminates cardiac arrhythmias in a one-dimensional ring of cardiac tissue. In this study, we demonstrate a novel approach to characterize the influence of HFS on ionic current gating dynamics, provide new insight into HFS of the myocardium, and suggest mechanisms underlying HFS-induced electrical activity.

  11. Strength Deterioration of Concrete in Sulfate Environment: An Experimental Study and Theoretical Modeling

    Directory of Open Access Journals (Sweden)

    Yingwu Zhou

    2015-01-01

    Full Text Available Sulfate corrosion is one of the most important factors responsible for the performance degradation of concrete materials. In this paper, an accelerated corrosion by a sulfate solution in a dry-wet cycle was introduced to simulate the external sulfate corrosion environment. The deterioration trend of concrete strength and development law of sulfate-induced concrete corrosion depth under sulfate attacks were experimentally studied. The damaged concrete section is simply but reasonably divided into uncorroded and corroded layers and the two layers can be demarcated by the sulfate corrosion depth of concrete. The accelerated corrosion test results indicated that the strength degradation of concrete by sulfate attack had a significant relation with the corrosion depth. Consequently, this paper aims to reveal such relation and thus model the strength degradation law. A large amount of experimental data has finally verified the validity and applicability of the models, and a theoretical basis is thus provided for the strength degradation prediction and the residual life assessment of in-service concrete structures under sulfate attacks.

  12. Theoretical models of the impact of climate change on natural populations, communities and ecosystems. Final report, 1989--1992

    Energy Technology Data Exchange (ETDEWEB)

    Wiegert, R.

    1992-12-31

    Land use change is a relatively understudied aspect of global change. In many cases, the impact of land use on plant and animal species may be far greater than the impact of climate change per se. As an integral part of our long-term studies of the response of animal populations to global change, we have focused on land use change as a dominant driving force. Climate change, no doubt, will also play a role in determining the future abundance and distribution of many species, but, for many species, the signal from climate change per se may be difficult to detect if we do not first understand the impact of land use change. This formed the dominant theme of the research by the PI (Pulliam). Both land use change and year to year climate change can directly affect other populations and two examples of this formed the focus of the remaining research, models of invertebrates in Carolina Bays and a model of a commercial estuarine population of blue crabs.

  13. Theoretical Study on the Flow of Refilling Stage in a Safety Injection Tank

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Sang [Halla Univ. Daejeon (Korea, Republic of)

    2017-10-15

    In this study, a theoretical analysis was performed to the flow of refilling stage in a safety injection tank, which is the core cooling system of nuclear power plant in an emergency. A theoretical model was proposed with a nonlinear governing equation defining on the flow of the refilling process of the coolant. Utilizing the Taylor-series expansion, the 1st - order approximation flow equation was obtained, along with its analytic solution of closed type, which could predict accurately the variations of free surface height and flow rate of the coolant. The availability of theoretical result was confirmed by comparing with previous experimental results.

  14. An in-depth analysis of theoretical frameworks for the study of care coordination

    Directory of Open Access Journals (Sweden)

    Sabine Van Houdt

    2013-06-01

    Full Text Available Introduction: Complex chronic conditions often require long-term care from various healthcare professionals. Thus, maintaining quality care requires care coordination. Concepts for the study of care coordination require clarification to develop, study and evaluate coordination strategies. In 2007, the Agency for Healthcare Research and Quality defined care coordination and proposed five theoretical frameworks for exploring care coordination. This study aimed to update current theoretical frameworks and clarify key concepts related to care coordination. Methods: We performed a literature review to update existing theoretical frameworks. An in-depth analysis of these theoretical frameworks was conducted to formulate key concepts related to care coordination.Results: Our literature review found seven previously unidentified theoretical frameworks for studying care coordination. The in-depth analysis identified fourteen key concepts that the theoretical frameworks addressed. These were ‘external factors’, ‘structure’, ‘tasks characteristics’, ‘cultural factors’, ‘knowledge and technology’, ‘need for coordination’, ‘administrative operational processes’, ‘exchange of information’, ‘goals’, ‘roles’, ‘quality of relationship’, ‘patient outcome’, ‘team outcome’, and ‘(interorganizational outcome’.Conclusion: These 14 interrelated key concepts provide a base to develop or choose a framework for studying care coordination. The relational coordination theory and the multi-level framework are interesting as these are the most comprehensive.

  15. [Nursing practice based on theoretical models: a qualitative study of nurses' perception].

    Science.gov (United States)

    Amaducci, Giovanna; Iemmi, Marina; Prandi, Marzia; Saffioti, Angelina; Carpanoni, Marika; Mecugni, Daniela

    2013-01-01

    Many faculty argue that theory and theorizing are closely related to the clinical practice, that the disciplinary knowledge grows, more relevantly, from the specific care context in which it takes place and, moreover, that knowledge does not proceed only by the application of general principles of the grand theories to specific cases. Every nurse, in fact, have  a mental model, of what may or may not be aware, that motivate and substantiate every action and choice of career. The study describes what the nursing theoretical model is; the mental model and the tacit  knowledge underlying it. It identifies the explicit theoretical model of the professional group that rapresents nursing partecipants, aspects of continuity with the theoretical model proposed by this degree course in Nursing.. Methods Four focus groups were made which were attended by a total of 22 nurses, rapresentatives of almost every Unit of Reggio Emilia Hospital's. We argue that the theoretical nursing model of each professional group is the result of tacit knowledge, which help to define the personal mental model, and the theoretical model, which explicitly underlying theoretical content learned applied consciously and reverted to / from nursing practice. Reasoning on the use of theory in practice has allowed us to give visibility to a theoretical model explicitly nursing authentically oriented to the needs of the person, in all its complexity in specific contexts.

  16. The hadronic final state in the deep inelastic electron-proton scattering. A comparison between the ZEUS data measured 1992 and theoretical models

    International Nuclear Information System (INIS)

    Schneider, J.L.

    1993-12-01

    The hadronic final state in deep inelastic e - P collisions has been studied with the 1992 data from the ZEUS detector at HERA. The hadronic final state is described by event topology variables like thrust and sphericity and also by variables like multiplicity and transverse momentum. These quantities require the reconstruction of the particle four moments which are calculated from calorimeter cell clusters (condensates). A detailed Monte-Carlo comparison between final state particles and condensates is presented. ZEUS data and model predictions are compared in the γ * P system. Good agreement between data and models is found in the x-Feynman and transverse momentum spectra and in the seagull plot. Mean thrust and sphericity are measured as functions of the invariant mass W of the hadronic final state. They significantly deviate from the model predictions, as do the mean multiplicities, which exceed the model predictions by about 1 unit. (orig.)

  17. Theoretical nuclear physics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    As the three-year period FY93-FY96 ended, there were six senior investigators on the grant full-time: Bulgac, Henley, Miller, Savage, van Kolck and Wilets. This represents an increase of two members from the previous three-year period, achieved with only a two percent increase over the budget for FY90-FY93. In addition, the permanent staff of the Institute for Nuclear Theory (George Bertsch, Wick Haxton, and David Kaplan) continued to be intimately associated with our physics research efforts. Aurel Bulgac joined the Group in September, 1993 as an assistant professor, with promotion requested by the Department and College of Arts and Sciences by September, 1997. Martin Savage, who was at Carnegie-Mellon University, jointed the Physics Department in September, 1996. U. van Kolck continued as research assistant professor, and we were supporting one postdoctoral research associate, Vesteinn Thorssen, who joined us in September, 1995. Seven graduate students were being supported by the Grant (Chuan-Tsung Chan, Michael Fosmire, William Hazelton, Jon Karakowski, Jeffrey Thompson, James Walden and Mitchell Watrous).

  18. Theoretical nuclear physics. Final report

    International Nuclear Information System (INIS)

    1997-01-01

    As the three-year period FY93-FY96 ended, there were six senior investigators on the grant full-time: Bulgac, Henley, Miller, Savage, van Kolck and Wilets. This represents an increase of two members from the previous three-year period, achieved with only a two percent increase over the budget for FY90-FY93. In addition, the permanent staff of the Institute for Nuclear Theory (George Bertsch, Wick Haxton, and David Kaplan) continued to be intimately associated with our physics research efforts. Aurel Bulgac joined the Group in September, 1993 as an assistant professor, with promotion requested by the Department and College of Arts and Sciences by September, 1997. Martin Savage, who was at Carnegie-Mellon University, jointed the Physics Department in September, 1996. U. van Kolck continued as research assistant professor, and we were supporting one postdoctoral research associate, Vesteinn Thorssen, who joined us in September, 1995. Seven graduate students were being supported by the Grant (Chuan-Tsung Chan, Michael Fosmire, William Hazelton, Jon Karakowski, Jeffrey Thompson, James Walden and Mitchell Watrous)

  19. Hydrodynamic Instability and Dynamic Burnout in Natural Circulation Two-Phase Flow. An Experimental and Theoretical Study

    International Nuclear Information System (INIS)

    Becker, Kurt M.; Jahnberg, S.; Haga, I.; Hansson, P.T.; Mathisen, R.P.

    1964-09-01

    A theoretical model for predicting the threshold of instability for two phase flow in a natural circulation loop is presented. The model calculates the flow transient caused by a step disturbance of the heat input, and is based upon the conservation laws of mass, momentum and energy in one dimensional form. Empirical correlations are used in the model for estimating the void fractions and the two-phase flow pressure drops. The equations are solved numerically in a finite difference approximation coded for a digital computer. An experimental study of the hydrodynamic instability and dynamic burnout in two-phase flow has been performed in a natural circulation loop in the pressure range from 10 to 70 atg. The test sections were round ducts of 20, 30 and 36 mm inner diameter and 4890 mm heated length. The experimental results showed that within the ranges tested, the stability of the flow increases with increasing pressure and increasing throttling before the test section, but decreases with increasing Inlet subcooling and increasing throttling after the test section. Comparing the natural circulation burnout steam qualities with corresponding forced circulation data shoved that the former data were low by a factor up to 2.5. However, by applying inlet throttling of the flow the burnout values approached and finally coincided with the forced circulation data. The present experimental results as well as data available from other sources have been compared with the stability thresholds obtained with the theoretical model. The comparisons included circular, annular and rod cluster geometries, and the agreement between the experimental and theoretical stability limits was good. Finally the application of the experimental and theoretical results on the assessment of boiling heavy water reactor design is discussed

  20. Toward a Theoretical Framework for Studying Climate Change Policies: Insights from the Case Study of Singapore

    Directory of Open Access Journals (Sweden)

    Ai Sian Ng

    2017-07-01

    Full Text Available The world decided in December 2015 to take actions to reduce global warming. To contribute toward this goal, this research examines possible policy levers for inclusion in the climate change ratification plan. A case study of the measures taken by the Republic of Singapore, a low-lying 719.2 km2 island without natural resources in Asia, is conducted. Being vulnerable to climate change impact and yet having to balance her people’s needs and economic progress with limited resources, the measures taken by this small country could offer policy insights for small states and states without access to alternative energy sources. This research analyzes the online policy documents posted by eleven organizations to answer the main research question of identifying policy levers as theoretical constructs to form a framework that can be used to study climate change policies. A qualitative data analysis software, QSR NVivo 10, is used to classify the proposed nodes developed by the researchers using a system perspective integrating the insights from the key international climate change frameworks with the theoretical concepts from the model of pro-environmental behavior. The findings can offer insights toward developing a new contextual influence framework, which can help strengthen policy development and outcome measurement.

  1. Model validation studies of solar systems, Phase III. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, L.J.; Winn, C.B.

    1978-12-01

    Results obtained from a validation study of the TRNSYS, SIMSHAC, and SOLCOST solar system simulation and design are presented. Also included are comparisons between the FCHART and SOLCOST solar system design programs and some changes that were made to the SOLCOST program. Finally, results obtained from the analysis of several solar radiation models are presented. Separate abstracts were prepared for ten papers.

  2. Plant systems/components modularization study. Final report. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort.

  3. Transportation library connectivity and development pooled fund study, final report.

    Science.gov (United States)

    2015-12-01

    This report is a record of the major activities and accomplishments of the Transportation Library : Connectivity and Development pooled fund study, TPF-5(237), from its approval by FHWA in : 2010 through its fifth and final annual meeting in August 2...

  4. Theoretical studies of field-reversed configurations (FRC) and experimental study of the FRC during translation

    International Nuclear Information System (INIS)

    Siemon, R.E.; Armstrong, W.T.; Chrien, R.E.

    1985-01-01

    Theoretical studies of FRC stability and transport are summarized. Finite Larmor radius theories are shown to be unreliable for explaining the experimentally observed stability to tilting. Control of the n=2 rotational instability has been demonstrated in two-dimensional hybrid code simulations, and the stability appears to be described within MHD if the nearly square equilibria that result from quadrupole fields are taken into account. Simulations of the lower hybrid drift instability in parameter regimes relevant to experiments show good agreement with a non-local theory of the instability. A 1.5-dimensional transport code shows agreement with the energy confinement time but disagreement with the flux loss time observed in FRX-C. The process of FRC translation in which the plasma is formed, translated into a DC solenoid and trapped by magnetic mirrors, has been studied in the FRX-C/T experiment. Efficient transfer of particles, energy and internal magnetic flux are observed with no enhancement of loss processes over in-situ FRC experiments. The axial velocity of the FRC can be estimated reasonably well with a simple model based on conservation of energy. Internal magnetic field probing during translation shows the expected structure of poloidal field and a complex distribution of generally weak toroidal fields. Measurements of radiated power indicate that radiation is a small fraction of the total plasma power loss (typically 8%). Translation has facilitated scaling studies of confinement over a wider range of parameters than were achieved by in-situ FRX-C experiments. For example, the variable xsub(s), the ratio of the separatrix radius to the metal wall radius, has been increased to about 0.7 by allowing the FRC to expand during translation. In all cases, particle confinement times agree within a factor of two with predictions by models that assume a lower hybrid drift resistivity. However, for the conditions studied there are indications that the experimental

  5. Couples coping with cancer: exploration of theoretical frameworks from dyadic studies.

    Science.gov (United States)

    Regan, Tim W; Lambert, Sylvie D; Kelly, Brian; Falconier, Mariana; Kissane, David; Levesque, Janelle V

    2015-12-01

    A diagnosis of cancer and subsequent treatment are distressing not only for the person directly affected, but also for their intimate partner. The aim of this review is to (a) identify the main theoretical frameworks underpinning research addressing dyadic coping among couples affected by cancer, (b) summarise the evidence supporting the concepts described in these theoretical frameworks, and (c) examine the similarities and differences between these theoretical perspectives. A literature search was undertaken to identify descriptive studies published between 1990 and 2013 (English and French) that examined the interdependence of patients' and partners' coping, and the impact of coping on psychosocial outcomes. Data were extracted using a standardised form and reviewed by three of the authors. Twenty-three peer-reviewed manuscripts were identified, from which seven theoretical perspectives were derived: Relationship-Focused Coping, Transactional Model of Stress and Coping, Systemic-Transactional Model (STM) of dyadic coping, Collaborative Coping, Relationship Intimacy model, Communication models, and Coping Congruence. Although these theoretical perspectives emphasised different aspects of coping, a number of conceptual commonalities were noted. This review identified key theoretical frameworks of dyadic coping used in cancer. Evidence indicates that responses within the couple that inhibit open communication between partner and patient are likely to have an adverse impact on psychosocial outcomes. Models that incorporate the interdependence of emotional responses and coping behaviours within couples have an emerging evidence base in psycho-oncology and may have greatest validity and clinical utility in this setting. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Theoretical ab initio study of Xenon pentafluoride anion. Mechanism of Xenon pseudorotation

    Science.gov (United States)

    Fleurat-Lessard, Paul; Durupthy, Olivier; Volatron, François

    2002-09-01

    Ab initio calculations have been performed on XeF 5- anion at the MP2 and CCSD(T) levels with a large basis set. Four extrema have been optimized and characterized by frequencies analysis. We find the absolute minimum to be of D 5h symmetry in accordance with the experimental data; the theoretical vibrational spectrum of this minimum is in good agreement with the experimental one. Three other extrema are found to be higher in energy depending on the angular separation of the Xenon lone pairs as predicted by the VSEPR theory. Finally the characterized transition state has been found to belong to the Xenon pseudorotation pathway.

  7. Study of the semi-theoretical relation of the hydraulic jump evolving ...

    African Journals Online (AJOL)

    This study has for objective to study the theoretical relation of the hydraulic jump by sill, evolving in an U-shaped channel, with a rough bed. Functional relations, in non-dimensional form, relating the jump characteristics, seeming the effect of the bed's roughness, are obtained. A comparative study with the hydraulic jump in ...

  8. Iridium-Catalysed ortho-Directed Deuterium Labelling of Aromatic Esters—An Experimental and Theoretical Study on Directing Group Chemoselectivity

    Directory of Open Access Journals (Sweden)

    Jennifer Devlin

    2015-06-01

    Full Text Available Herein we report a combined experimental and theoretical study on the deuterium labelling of benzoate ester derivatives, utilizing our developed iridium N-heterocyclic carbene/phosphine catalysts. A range of benzoate esters were screened, including derivatives with electron-donating and -withdrawing groups in the para- position. The substrate scope, in terms of the alkoxy group, was studied and the nature of the catalyst counter-ion was shown to have a profound effect on the efficiency of isotope exchange. Finally, the observed chemoselectivity was rationalized by rate studies and theoretical calculations, and this insight was applied to the selective labelling of benzoate esters bearing a second directing group.

  9. Studies of elasticity, sound propagation and attenuation of acoustic modes in granular media: final report

    Energy Technology Data Exchange (ETDEWEB)

    Makse, Hernan A. [City College of New York, NY (United States). Levich Inst., Dept. of Physcis; Johnson, David L. [Schlumberger-Doll Research, Cambridge, MA (United States)

    2014-09-03

    This is the final report describing the results of DOE Grant # DE-FG02-03ER15458 with original termination date of April 31, 2013, which has been extended to April 31, 2014. The goal of this project is to develop a theoretical and experimental understanding of sound propagation, elasticity and dissipation in granular materials. The topic is relevant for the efficient production of hydrocarbon and for identifying and characterizing the underground formation for storage of either CO2 or nuclear waste material. Furthermore, understanding the basic properties of acoustic propagation in granular media is of importance not only to the energy industry, but also to the pharmaceutical, chemical and agricultural industries. We employ a set of experimental, theoretical and computational tools to develop a study of acoustics and dissipation in granular media. These include the concept effective mass of granular media, normal modes analysis, statistical mechanics frameworks and numerical simulations based on Discrete Element Methods. Effective mass measurements allow us to study the mechanisms of the elastic response and attenuation of acoustic modes in granular media. We perform experiments and simulations under varying conditions, including humidity and vacuum, and different interparticle force-laws to develop a fundamental understanding of the mechanisms of damping and acoustic propagation in granular media. A theoretical statistical approach studies the necessary phase space of configurations in pressure, volume fraction to classify granular materials.

  10. Theoretical study of the electronic structure of f-element complexes by quantum chemical methods

    International Nuclear Information System (INIS)

    Vetere, V.

    2002-09-01

    This thesis is related to comparative studies of the chemical properties of molecular complexes containing lanthanide or actinide trivalent cations, in the context of the nuclear waste disposal. More precisely, our aim was a quantum chemical analysis of the metal-ligand bonding in such species. Various theoretical approaches were compared, for the inclusion of correlation (density functional theory, multiconfigurational methods) and of relativistic effects (relativistic scalar and 2-component Hamiltonians, relativistic pseudopotentials). The performance of these methods were checked by comparing computed structural properties to published experimental data, on small model systems: lanthanide and actinide tri-halides and on X 3 M-L species (X=F, Cl; M=La, Nd, U; L = NH 3 , acetonitrile, CO). We have thus shown the good performance of density functionals combined with a quasi-relativistic method, as well as of gradient-corrected functionals associated with relativistic pseudopotentials. In contrast, functionals including some part of exact exchange are less reliable to reproduce experimental trends, and we have given a possible explanation for this result . Then, a detailed analysis of the bonding has allowed us to interpret the discrepancies observed in the structural properties of uranium and lanthanides complexes, based on a covalent contribution to the bonding, in the case of uranium(III), which does not exist in the lanthanide(III) homologues. Finally, we have examined more sizeable systems, closer to experimental species, to analyse the influence of the coordination number, of the counter-ions and of the oxidation state of uranium, on the metal-ligand bonding. (author)

  11. A theoretical study of pump–probe experiment in single-layer ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 6. A theoretical study of pump–probe experiment in single-layer, bilayer and multilayer graphene ... Here we use it as a tool to study the phenomenon of anomalous Rabi oscillations in graphene that was predicted recently in single-layer graphene.

  12. Curriculum, Curriculum Development, Curriculum Studies? Problematising Theoretical Ambiguities in Doctoral Theses in the Education Field

    Science.gov (United States)

    du Preez, Petro; Simmonds, Shan

    2014-01-01

    Theoretical ambiguities in curriculum studies result in conceptual mayhem. Accordingly, they hinder the development of the complicated conversation on curriculum as a verb. This article aims to contribute to reconceptualizing curriculum studies as a dynamic social practice that aspires to thinking and acting with intelligences and sensitivity so…

  13. THEORETICAL AND METHODOLOGICAL APPROACHES TO THE STUDY OF PROTEST ACTIVITY IN THE WESTERN SOCIOLOGICAL THOUGHT

    OpenAIRE

    Купрєєва, Ю. О.

    2015-01-01

    In this article the author discusses the main theoretical and methodological approaches to the study of protest activity. Among them - the theory of collective behavior, the relative deprivation theory, the new social movements theory and the resource mobilization theory. Highlighted their strengths and weaknesses. Focused on the new direction of protest studies connected with the development of the Internet.

  14. Theoretical and experimental study of the achievable separation power in resistive-glass atmospheric pressure ion mobility spectrometry.

    Science.gov (United States)

    Kwasnik, Mark; Fernández, Facundo M

    2010-07-15

    We present a detailed investigation of the performance of our previously reported nanoelectrospray high-resolution resistive-glass atmospheric pressure drift tube ion mobility spectrometer constructed with monolithic resistive-glass desolvation and drift regions. Using experimental spectral data and theoretical pulse width and diffusion variables, we compare theoretical and experimental resolving powers achievable under a variety of field strengths and ion gate pulse widths. The effects of instrumental and operational parameters on the resolution achievable in chromatographic terms are also discussed. Following characterization of the separation power of the instrument, experimental spectral peak width data is fitted by a least-squares procedure to a pre-existing semi-empirical model developed to study contributions to peak width other than initial pulse width and diffusional broadening. The model suggests possible contributions to the final measured peak width from electric field inhomogeneity and minor contributions from instrumental parameters such as anode size, anode-to-anode grid distance and drift gas flow rate. The model also reveals an unexpected ion gate width dependence on the final measured peak width that we attribute to non-ideal performance of the Bradbury-Nielsen ion gate and limitations in the design of our pulsing-electronics. Copyright 2010 John Wiley & Sons, Ltd.

  15. Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism

    Science.gov (United States)

    2016-06-09

    AFRL-AFOSR-VA-TR-2016-0204 Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism Jose Rodriguez CALIFORNIA...TITLE AND SUBTITLE Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism 5a.  CONTRACT NUMBER 5b.  GRANT...SUBJECT TERMS quantum magnetism , HTS, superconductivity 16.  SECURITY CLASSIFICATION OF: 17.  LIMITATION OF       ABSTRACT UU 18.  NUMBER        OF

  16. Theoretical and experimental study of modes associated to ion cyclotron heating on TFR

    International Nuclear Information System (INIS)

    Pignol, L.

    1985-05-01

    In this work, the ion cyclotron wave evolution is followed thanks to a coherent scattering device using carbon dioxide laser radiation. A theoretical part presents the dispersion equation that obey the waves excited in the plasma by antenna emitting ion cyclotron frequency. Then measurements given by the diagnostic are given. Fast and slow waves evidenced theoretically, are experimentally observed. Two simple theoretical models allow to extract physical quantities characteristics of the two modes. These two modes are followed along the radial coordinate of the tore and their behavior through the hybrid curve is studied. measured spectra shape is shown to confirm the described numerical code validity. Time study of the slow wave shows of internal relaxation phenomenon of plasma [fr

  17. Theoretical and experimental studies on critical heat flux in subcooled boiling and vertical flow geometry

    International Nuclear Information System (INIS)

    Staron, E.

    1996-01-01

    Critical Heat Flux is a very important subject of interest due to design, operation and safety analysis of nuclear power plants. Every new design of the core must be thoroughly checked. Experimental studies have been performed using freon as a working fluid. The possibility of transferring of results into water equivalents has been proved. The experimental study covers vertical flow, annular geometry over a wide range of pressure, mass flow and temperature at inlet of test section. Theoretical models of Critical Heat Flux have been presented but only those which cover DNB. Computer programs allowing for numerical calculations using theoretical models have been developed. A validation of the theoretical models has been performed in accordance with experimental results. (author). 83 refs, 32 figs, 4 tabs

  18. EFFICIENCY OF ISO 9001 IN PORTUGAL: A QUALITATIVE STUDY FROM A HOLISTIC THEORETICAL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Alcina Dias

    2013-03-01

    Full Text Available The purpose of this paper is to analy se the efficiency of ISO 9001 from a holistic theoretical approach where the Contingency theory, the Institutional theory and the Resources-Based View are integrated. The study was carried out in companies of different sectors of activity in Portugal, based on a qualitative methodology (interviews. The fact of the interviews having been undertaken under an ISO 9001 structure made it easier for companies to grasp the issues under investigation. An ISO 9001 characterisation was carried out on a theoretical framework approach and findings point out efficiency gains and revealed that the absence of ISO 9001 would work as a competitive disadvantage. The contribution of this research aims to reinforce the state of art as concerns the theoretical scope of analysis of these issues enriched by the case study achievement.

  19. Final report for NIF chamber dynamics studies. Final report (May 1997), Subcontract No. B291847

    International Nuclear Information System (INIS)

    Peterson, P.F.; Jin, H.; Scott, J.M.

    1997-01-01

    The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. Various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the final optics debris shields from an excessive coating (> 10 Angstrom) of target debris and ablated material, thereby prolonging their lifetime between change- outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. In addition to the work described briefly above, we performed extensive analysis of the target-chamber thermal response to in- chamber CO 2 Cleaning and of work performed to model the behavior of silica vapor. The work completed this year has been published in several papers and a dissertation -6 This report provides a summary of the work completed this year, as well as copies of

  20. Spin-dependent Hall effect in degenerate semiconductors: a theoretical study

    International Nuclear Information System (INIS)

    Idrish Miah, M

    2008-01-01

    The spin-dependent Hall (SDH) effect in degenerate semiconductors is investigated theoretically. Starting from a two-component drift-diffusion equation, an expression for SDH voltage (V SDH ) is derived, and drift and diffusive contributions to V SDH are studied. For the possible enhancement of the diffusive part, degenerate and nondegenerate cases are examined. We find that due to an increase in the diffusion coefficient V SDH increases in a degenerate semiconductor, consistent with the experimental observations. The expression for V SDH is reduced in three limiting cases, namely diffusive, drift-diffusion crossover and drift, and is analysed. The results agree with those obtained in recent theoretical investigations.

  1. Theoretical study of band alignment in nano-porous ZnO interacting with substituted Phthalocyanines

    OpenAIRE

    Wahnón Benarroch, Perla; Palacios Clemente, Pablo

    2011-01-01

    The aim of this work is the theoretical study of the band alignment between the two components of a hybrid organic-inorganic solar-cell. The working organic molecules are metal tetra-sulphonated phthalocyanines (M-Pc) and the inorganic material is nano-porous ZnO growth in the 001 direction. The theoretical calculations are being made using the density functional theory (DFT) using a GGA functional with the SIESTA code, which projects electron wave functions and density onto a real space grid...

  2. Laser fusion study. Final report, volume I, study results

    International Nuclear Information System (INIS)

    1975-06-01

    The primary goal of this study was to devise, evaluate, and conceptually design a complete, end-to-end, alignment system capable of handling 30 to 32 Shiva amplifier chains to specified accuracies in space and time. A secondary goal was to accomplish the primary goal with an acceptably low development and procurement cost and with an acceptably high day-after-day performance reliability. This report presents such a system: it is comprised of sensors, actuating mechanisms, controls, and displays that perform well within the current art-state. (U.S.)

  3. Red/blue shifting hydrogen bonds in acetonitrile-dimethyl sulphoxide solutions: FTIR and theoretical studies

    Science.gov (United States)

    Kannan, P. P.; Karthick, N. K.; Mahendraprabu, A.; Shanmugam, R.; Elangovan, A.; Arivazhagan, G.

    2017-07-01

    FTIR spectra of neat acetonitrile (AN), dimethyl sulphoxide (DMSO) and their binary solutions at various mole fractions have been recorded at room temperature. Theoretical calculations have also been carried out on acetonitrile (monomer, dimer), dimethyl sulphoxide (monomer, dimer) and AN - DMSO complex molecules. 1:2 (AN:DMSO) and 2:1 complexation through the red shifting (AN) C - H ⋯ O = S(DMSO) and blue shifting (DMSO) C - H ⋯ N ≡ C(AN) hydrogen bonds has been identified. The experimental and theoretical studies favour the presence of both the monomer and dimer in liquid AN, but only closed dimers in DMSO. The dipole-dipole interactions existed in AN and DMSO dimers disappear in the complex molecules. Partial π bond between S and O atoms, and three lone pair of electrons on oxygen atom of DMSO have been noticed theoretically.

  4. First study of the interference between initial and final state radiation at the Z resonance

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barate, R; Barbi, M S; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gerdyukov, L N; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Korcyl, K; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Novák, M; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Rybin, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G

    1996-01-01

    The interference between initial and final state radiation in the process \\eemm\\ at $\\sqs \\approx \\MZ$ has been studied by measuring the forward-backward asymmetry as a function of the acoplanarity angle between the final state muons. The interference is expected to be sensitive to the space-time separation of the initial and final state radiation. The measured asymmetry distribution has been compared to theoretical predictions using the \\KORALZ\\ generator, with and without ørdalph\\ interference. The magnitude of the interference between initial and $ \\pm 0.06 $ (syst.) \\GeV} . \\end{center} has been extracted. The interpretation of this result is discussed. There is an additional uncertainty in the estimate of \\GZ\\ from as yet uncalculated higher order interference terms. By assuming a value of \\GZ\\ consistent with the world average, the data were used to estimate the size of these uncalculated corrections. The interference between initial and final state radiation in the process \\eemm\\ at \\sqs \\approx \\MZ h...

  5. Theoretical study, and infrared and Raman spectra of copper(II) chelated complex with dibenzoylmethane

    DEFF Research Database (Denmark)

    Nekoei, A.-R.; Vakili, M.; Hakimi-Tabar, M.

    2014-01-01

    There are some discrepancies in both the vibrational assignments and in the metal-ligand (M-L) bond strengths predicted in the previous studies on the copper (II) chelated complex of dibenzoylmethane, Cu(dbm)2. Also, there is a lack of theoretical structure, Raman spectrum and full vibrational as...

  6. [Habermas and Paulo Freire: theoretical referrals for the study on communication in nursing].

    Science.gov (United States)

    Larocca, Liliana Muller; Mazza, Verônica de Azevedo

    2003-08-01

    The present work has the objective of introducing the ideas of Jürgen Habermas and Paulo Freire about the dialogue as a fundamental human phenomenon, data on their trajectories of life, ideological approaches when locating the human being through history and their relevance as theoretical referrals for the study on communication in the process of the nurse's work.

  7. A Comparative Study of Theoretical Graph Models for Characterizing Structural Networks of Human Brain

    Directory of Open Access Journals (Sweden)

    Xiaojin Li

    2013-01-01

    Full Text Available Previous studies have investigated both structural and functional brain networks via graph-theoretical methods. However, there is an important issue that has not been adequately discussed before: what is the optimal theoretical graph model for describing the structural networks of human brain? In this paper, we perform a comparative study to address this problem. Firstly, large-scale cortical regions of interest (ROIs are localized by recently developed and validated brain reference system named Dense Individualized Common Connectivity-based Cortical Landmarks (DICCCOL to address the limitations in the identification of the brain network ROIs in previous studies. Then, we construct structural brain networks based on diffusion tensor imaging (DTI data. Afterwards, the global and local graph properties of the constructed structural brain networks are measured using the state-of-the-art graph analysis algorithms and tools and are further compared with seven popular theoretical graph models. In addition, we compare the topological properties between two graph models, namely, stickiness-index-based model (STICKY and scale-free gene duplication model (SF-GD, that have higher similarity with the real structural brain networks in terms of global and local graph properties. Our experimental results suggest that among the seven theoretical graph models compared in this study, STICKY and SF-GD models have better performances in characterizing the structural human brain network.

  8. A Theoretical Framework to Study Variations in Workplace Violence Experienced by Emergency Responders

    NARCIS (Netherlands)

    L. van Reemst (Lisa)

    2016-01-01

    textabstractEmergency responders are often sent to the front line and are often confronted with aggression and violence in inter- action with citizens. According to previous studies, some professionals experience more workplace violence than others. In this article, the theoretical framework to

  9. A theoretical framework to study variations in workplace violence experienced by emergency responders

    NARCIS (Netherlands)

    L. van Reemst (Lisa)

    2016-01-01

    markdownabstractEmergency responders are often sent to the front line and are often confronted with aggression and violence in interaction with citizens. According to previous studies, some professionals experience more workplace violence than others. In this article, the theoretical framework to

  10. Theoretical study of the ground state of (EDO-TTF)(2)PF6

    NARCIS (Netherlands)

    Linker, Gerrit-Jan; van Duijnen, Piet Th.; van Loosdrecht, Paul H.M.; Broer, Ria

    2015-01-01

    In this paper we present a theoretical study of the nature of the ground state of the (EDO-TTF)(2)PF6 charge transfer salt by using ab initio quantum chemical theory for clusters in vacuum, for embedded clusters and for the periodic system. Exemplary for other organic charge transfer systems, we

  11. Theoretical and experimental study of high-Q resonant modes in terahertz optical systems

    NARCIS (Netherlands)

    Jellema, Willem; Withington, S.; Trappe, Neil; Murphy, J. A.; Wild, Wolfgang

    2004-01-01

    The existence of multiple reflections in terahertz optical system causes numerous problems in applications ranging from astronomical to medical instrumentation. We have performed a detailed theoretical study, using waveguide and free-space modal matching, of the high-Q modes that appear on THz

  12. Theoretical studies on the stability of the salts formed by DTDO with ...

    Indian Academy of Sciences (India)

    Toggle navigation. Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About ... Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 4. Theoretical studies on the stability of the salts formed by ... Keywords. Salts; conformations; stability; density functional theory, energetic materials.

  13. Coulomb drag in anisotropic systems: a theoretical study on a double-layer phosphorene

    NARCIS (Netherlands)

    Saberi-Pouya, S.; Vazifehshenas, T.; Farmanbar Gelepordsari, M.; Salavati-Fard, T.

    2016-01-01

    We theoretically study the Coulomb drag resistivity in a double-layer electron system with highly anisotropic parabolic band structure using Boltzmann transport theory. As an example, we consider a double-layer phosphorene on which we apply our formalism. This approach, in principle, can be tuned

  14. Theoretical study on ground-state triple proton transfer for formic ...

    Indian Academy of Sciences (India)

    Theoretical study on ground-state proton/H-atom exchange in formic acid clusters through different H-bonded bridges. HUA FANG. Department of Chemistry and Material Science, College of Science, Nanjing Forestry University, Nanjing 210037, People's Republic of China. Email: susanfang20@gmail.com. Contents.

  15. Theoretical study of the reactivity trends in the Cl-abstraction ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 5. Theoretical study of the reactivity trends in the Cl-abstraction reactions of CHCl3 + CHX·−/CX 2 · − (X = Cl, Br and I). Jun Xi Liang Zhi Yuan Geng Yong Cheng Wang. Volume 123 Issue 5 September 2011 pp 755-763 ...

  16. Theoretical study of two-element array of equilateral triangular patch ...

    Indian Academy of Sciences (India)

    The radiation characteristics of a two-element array of equilateral triangular patch microstrip antenna on a ferrite substrate are studied theoretically by considering the presence of bias magnetic field in the direction of propagation of electromagnetic waves. It is found that the natural modes of propagation in the direction of ...

  17. Interaction between adrenaline and dibenzo-18-crown-6: Electrochemical, nuclear magnetic resonance, and theoretical study

    Science.gov (United States)

    Yu, Zhang-Yu; Liu, Tao; Wang, Xue-Liang

    2014-12-01

    The interaction between adrenaline (Ad) and dibenzo-18-crown-6 (DB18C6) was studied by cyclic voltammetry, nuclear magnetic resonance spectroscopy, and the theoretical calculations, respectively. The results show that DB18C6 will affect the electron transfer properties of Ad. DB18C6 can form stable supramolecular complexes with Ad through ion-dipole and hydrogen bond interactions.

  18. Electronic structure of copper phthalocyanine : An experimental and theoretical study of occupied and unoccupied levels

    NARCIS (Netherlands)

    Evangelista, Fabrizio; Carravetta, Vincenzo; Stefani, Giovanni; Jansik, Branislav; Alagia, Michele; Stranges, Stefano; Ruocco, Alessandro

    2007-01-01

    An experimental and theoretical study of the electronic structure of copper phthalocyanine (CuPc) molecule is presented. We performed x-ray photoemission spectroscopy (XPS) and photoabsorption [x-ray absorption near-edge structure (XANES)] gas phase experiments and we compared the results with

  19. Multnomah County Hydrokinetic Feasibility Study: Final Feasibility Study Report

    Energy Technology Data Exchange (ETDEWEB)

    Spain, Stephen

    2012-03-15

    HDR has completed a study of the technical, regulatory, and economic feasibility of installing hydrokinetic turbines under the Morrison, Broadway, and Sellwood bridges. The primary objective of installing hydrokinetic turbines is a demonstration of in-stream hydrokinetic technologies for public education and outreach. Due to the low gradient of the Lower Willamette and the effects of the tide, velocities in the area in consideration are simply not high enough to economically support a commercial installation. While the velocities in the river may at times provide enough energy for a commercial turbine to reach capacity, the frequency and duration of high flow events which provide suitable velocities is not sufficient to support a commercial hydrokinetic installation. We have observed that over an 11 year period, daily average velocities in the Lower Willamette exceeded a nominal cut-in speed of 0.75 m/s only 20% of the time, leaving net zero power production for the remaining 80% of days. The Sellwood Bridge site was estimated to have the best hydrokinetic resource, with an estimated average annual production of about 9,000 kWh. The estimated production could range from 2,500 kWh to 15,000 kWh. Based on these energy estimates, the amount of revenue generated through either a power purchase agreement (PPA) or recovered through net metering is not sufficient to repay the project costs within the life of the turbine. The hydrokinetic resource at the Morrison and Broadway Bridges is slightly smaller than at the Sellwood Bridge. While the Broadway and Morrison Bridges have existing infrastructure that could be utilized, the project is not expected to generate enough revenue to repay the investment. Despite low velocities and energy production, the sites themselves are favorable for installation of a demonstration or experimental project. With high public interest in renewable energy, the possibility exists to develop a hydrokinetic test site which could provide

  20. QCD studies with the hadronic final states at HERA

    International Nuclear Information System (INIS)

    Zhang, Z.

    1996-01-01

    New and complementary results with respect to the inclusive proton structure function have been obtained in the HERA new kinematical domain by studying extensively the hadronic final states by both H1 and ZEUS collaborations. Shown here are the observation of hard partonic scattering in photoproduction and diffractive interactions, the comparison of hadron production in the central rapidity region between photoproduction and deep inelastic scattering, the precise determination of α, over a large energy range in a single experiment, and the evidence of the hard diffractive scattering. (author)

  1. Biomechanical study of the final push-pull in archery.

    Science.gov (United States)

    Leroyer, P; Van Hoecke, J; Helal, J N

    1993-02-01

    The purpose of this study was to analyse archery performance among eight archers of different abilities by means of displacement pull-hand measurements during the final push-pull phase of the shoot. The archers showed an irregular displacement negatively related to their technical level. Displacement signal analysis showed high power levels in both the 0-5 Hz and 8-12 Hz ranges. The latter peak corresponds to electromyographic tremor observed during a prolonged push-pull effort. The results are discussed in relation to some potentially helpful training procedures such as biofeedback and strength conditioning.

  2. Study of some options for the CLIC final focusing quadrupole

    CERN Document Server

    Aleksa, Martin

    2002-01-01

    This paper describes a feasibility study and the preliminary design for the CLIC final focusing quadrupoles. A possible design for a quadrupole consisting of rare-earth permanent magnet material is introduced. Due to its radiation hardness and its high remanence, Sm2Co17 seems to be the best suited permanent magnet material. The very high field gradients of 450 T/m can be achieved if pre-magnetized sectors made of permanent magnet material are assembled in ”zero clearance” design. An alternative solution with small superconducting coils is presented and briefly discussed, but would need further investigations.

  3. Final report for the year 2001 on experimental and theoretical investigations of irradiation effects on physical and mechanical properties of iron and RAFM steels

    DEFF Research Database (Denmark)

    Singh, Bachu Narain

    2003-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties have been studied both experimentally and theoretically. Specimens of pure iron and RAFM (reduced activation ferritic-martensic) steels were irradiated todifferent dose levels and at different irradiation...... temperatures. The resulting microstructure was characterized using transmission electron microscopy, positron annihilation spectroscopy and electrical resistivity measurements. Mechanical properties weredetermined by uniaxial tensile testing. Dislocation-loop interaction, formation of rafts of loops, radiation...... hardening and formation of “cleared channels” were studied using different computational techniques. Experiments have shown that nano-voids areformed both in pure iron and F82H steel already at 50°C. In pure iron, the formation of nano-voids is detected already at a dose level of ~10-3 dpa. Also in iron...

  4. Combined experimental and theoretical study of the mechanism and enantioselectivity of palladium-catalyzed intermolecular Heck coupling

    DEFF Research Database (Denmark)

    Henriksen, Signe Teuber; Norrby, Per-Ola; Kaukoranta, Päivi

    2008-01-01

    . The steric interactions in this transition state fully account for the enantioselectivity observed with the ligands studied. The calculations also predict relative reactivity and nonlinear mixing effects for the investigated ligands; these predictions are fully validated by experimental testing. Finally......The asymmetric Heck reaction using P,N-ligands has been studied by a combination of theoretical and experimental methods. The reaction follows Halpern-style selectivity; that is, the major isomer is produced from the least favored form of the pre-insertion intermediate. The initially formed Ph......, the low conversion observed with some catalysts was found to be caused by inactivation due to weak binding of the ligand to Pd(0). Adding monodentate PPh3 alleviated the precipitation problem without deteriorating the enantioselectivity and led to one of the most effective catalytic systems to date....

  5. Structural changes in 2-diarylthiophene-substituted starburst compounds upon charging: a theoretical and spectroelectrochemical study.

    Science.gov (United States)

    Solc, Roland; Lukes, Vladimír; Rapta, Peter; Hartmann, Horst; Dunsch, Lothar

    2008-12-01

    The role of charging in structural changes of 2-diarylaminothiophene-substituted starburst compounds is clarified by combining theoretical and spectroelectrochemical studies. A systematic and comparative theoretical calculation based on density functional theory and semiempirical Austin Model 1 (AM1) calculations is performed on the neutral and charged states of four model tris(5-diarylamino-5-thienyl)-terminated starburst compounds with a central triphenylamine and 1,3,5-triphenylbenzene moiety. Our results indicate that the charging of molecules leads to structural changes by quinoid-type components mostly on the dendrimers terminated by phenothiazinyl fragments. Based on the optimal geometries, the spectroscopic properties were calculated using the semiempirical Zerner's intermediate neglect overlap method. The presented theoretical results and the spin electron distributions of charged states and their spectra are supported by the spectroelectrochemical observations caused by the different electron localization within the studied molecules after charging. The satisfactory agreement between theoretical electronic transitions and experimental values indicates that a rational design of tunable molecular layers in organic devices based on the starburst compounds described is possible.

  6. Theoretical spectroscopic study of the conjugate microcystin-LR-europium cryptate

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Julio G.; Dutra, Jose Diogo L.; Costa Junior, Nivan B. da; Freire, Ricardo O., E-mail: rfreire@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Quimica; Alves Junior, Severino; Sa, Gilberto F. de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Quimica Fundamental

    2013-02-15

    In this work, theoretical tools were used to study spectroscopic properties of the conjugate microcystin-LR-europium cryptate. The Sparkle/AM1 model was applied to predict the geometry of the system and the INDO/S-CIS model was used to calculate the excited state energies. Based on the Judd-Ofelt theory, the intensity parameters were predicted and a theoretical model based on the theory of the 4f-4f transitions was applied to calculate energy transfer and backtransfer rates, radiative and non-radiative decay rates, quantum efficiency and quantum yield. A detailed study of the luminescent properties of the conjugate Microcystin-LR-europium cryptate was carried out. The results show that the theoretical quantum yield of luminescence of 23% is in good agreement with the experimental value published. This fact suggests that this theoretical protocol can be used to design new systems in order to improve their luminescence properties. The results suggest that this luminescent system may be a good conjugate for using in assay ELISA for detection by luminescence of the Microcystin-LR in water. (author)

  7. Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK

    Directory of Open Access Journals (Sweden)

    Yuwei Fu

    2016-08-01

    give the formation of IV a, IV b and products of CF3 + CF-CF3 in pathway IV. Although IV a is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF3, C = CF2 as well as C-CF3 species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway V I of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states. This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK.

  8. Curriculum, curriculum development, curriculum studies? Problematising theoretical ambiguities in doctoral theses in the education field

    Directory of Open Access Journals (Sweden)

    Petro du Preez

    2014-06-01

    Full Text Available Theoretical ambiguities in curriculum studies result in conceptual mayhem. Accordingly, they hinder the development of the complicated conversation on curriculum as a verb. This article aims to contribute to reconceptualizing curriculum studies as a dynamic social practice that aspires to thinking and acting with intelligences and sensitivity so as to understand oneself and others. It also raises awareness that equating all forms of research on curriculum with curriculum studies dilutes the scope of the conversation. This exploration asks two key questions: What is the nature of doctoral theses in the field of education's theoretical contributions to nuances of curriculum (curriculum, curriculum development, and curriculum studies? In what ways do these theses perpetuate or even add to current ambiguities in the discipline of curriculum studies? The exploration of these two questions draws on a critical meta-study of 511 theses completed in South African universities (2005-2012 conducted using a three level process. It appears that the main detractions of these theses are that some of them see curriculum studies as a dumping ground and others make no theoretical contribution to the discipline. The article concludes by suggesting ways which would encourage the intellectual advancement of curriculum studies through rigorous disciplinarity.

  9. Theoretical Study of the Effects of Di-Muonic Molecules on Muon-Catalyzed Fusion

    Science.gov (United States)

    2012-03-01

    MOLECULES ON MUON -CATALYZED FUSION DISSERTATION Eugene V. Sheely, Lieutenant Colonel, USA DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY...THEORETICAL STUDY OF THE EFFECTS OF DI-MUONIC MOLECULES ON MUON -CATALYZED FUSION DISSERTATION Presented to the Faculty...potential of enhancing the muon -catalyzed fusion reaction rate. In order to study these di-muonic molecules a method of non-adiabatic quantum mechanics

  10. Studying Scale-Up and Spread as Social Practice: Theoretical Introduction and Empirical Case Study.

    Science.gov (United States)

    Shaw, James; Shaw, Sara; Wherton, Joseph; Hughes, Gemma; Greenhalgh, Trisha

    2017-07-07

    Health and care technologies often succeed on a small scale but fail to achieve widespread use (scale-up) or become routine practice in other settings (spread). One reason for this is under-theorization of the process of scale-up and spread, for which a potentially fruitful theoretical approach is to consider the adoption and use of technologies as social practices. This study aimed to use an in-depth case study of assisted living to explore the feasibility and usefulness of a social practice approach to explaining the scale-up of an assisted-living technology across a local system of health and social care. This was an individual case study of the implementation of a Global Positioning System (GPS) "geo-fence" for a person living with dementia, nested in a much wider program of ethnographic research and organizational case study of technology implementation across health and social care (Studies in Co-creating Assisted Living Solutions [SCALS] in the United Kingdom). A layered sociological analysis included micro-level data on the index case, meso-level data on the organization, and macro-level data on the wider social, technological, economic, and political context. Data (interviews, ethnographic notes, and documents) were analyzed and synthesized using structuration theory. A social practice lens enabled the uptake of the GPS technology to be studied in the context of what human actors found salient, meaningful, ethical, legal, materially possible, and professionally or culturally appropriate in particular social situations. Data extracts were used to illustrate three exemplar findings. First, professional practice is (and probably always will be) oriented not to "implementing technologies" but to providing excellent, ethical care to sick and vulnerable individuals. Second, in order to "work," health and care technologies rely heavily on human relationships and situated knowledge. Third, such technologies do not just need to be adopted by individuals; they need

  11. Theoretical and Experimental Study on the Permittivity of CdTe in the Terahertz Band

    Directory of Open Access Journals (Sweden)

    Sun Wang

    2018-02-01

    Full Text Available The phonon dispersion spectrum, eigenvector, and lattice vibration frequency of cadmium telluride with a zinc blende structure have been investigated using the density functional theory, and the permittivity of cadmium telluride crystal is numerically calculated. The permittivity of the crystal is measured using the terahertz time-domain spectroscopy system. The experimental results are consistent with the theoretical calculations on the modified local density approximation, the general gradient approximation, and the modified general gradient approximation. Finally, the differences among the three approximate exchange correlation potentials indicate that in the terahertz region, the permittivity of cadmium telluride is dominantly contributed by the coupling between electron and phonon; however, the phonon frequencies of transverse wave and longitudinal wave were sensitive to electron density distribution.

  12. Theoretical study to investigate the impact of plasma parameters on the catalyst nanoparticle growth

    International Nuclear Information System (INIS)

    Gupta, R; Sharma, S C; Gupta, N

    2017-01-01

    The plasma kinetics based model is adopted to elucidate the effect of plasma parameters on the nucleation and growth mechanism of catalyst nanoparticle. The present model considers the plasma processing of thin catalyst film, power equalization at the film surface, flux and kinetics of plasma species (electrons, ions, and neutrals). In our investigation, it is found that catalyst nanoparticle diameter decreases with increase in ion number density in plasma. Moreover, it is also found that catalyst film thickness significantly affect the catalyst nanoparticle size i.e., catalyst nanoparticle diameter increases with catalyst film thickness. In addition, it is observed that the substrate temperature increases during the plasma processing and finally achieve saturation. Our theoretical results are in good agreement with the experimental results. (paper)

  13. Making sense with multimedia: A text theoretical study of a digital format integrating writing and video

    Directory of Open Access Journals (Sweden)

    Martin Engebretsen

    2006-12-01

    Full Text Available Digital text formats that allow a close interaction between writing and video represent new possibilities and challenges for the communication of educational content. What are the premises for functional and appropriate communication through web-based, multimedial text formats?This article explores the digital writing-video format from a structural, theoretical perspective. To begin with, the two media’s respective characteristics are discussed and compared as carriers of complex signs. Thereafter, the focus is upon how writing and video elements can be accommodated to web media. Finally, the article discusses the conditions for optimal co-ordination and interaction between the two media types within the framework of an integrated design. A design example is presented.

  14. Theoretical study of inner-shell ionization by heavy-particle impact

    International Nuclear Information System (INIS)

    Sarkadi, L.

    2000-01-01

    Complete text of publication follows. In our previous theoretical studies of inner-shell ionization of atoms by heavy-particle impact we applied the so-called coupled-states model. This theory was constructed to account for the intra-shell coupling effects in L-shell ionization. The model satisfactory reproduced the main tendencies of the measured L-shell ionization data (cross sections, L 3 -subshell alignment parameters) in a broad range of the collision energy, target and projectile atomic number. However, the accuracy of these calculations was uncertain, because the coupled-states model contained a series of approximation. The most questionable assumption was that the changes of the cross sections due to the subshell coupling effects were expressed by correction factors. The correction factors were derived considering only some representative transitions between the bound and continuum states, namely transitions into states of energy E f = 0 and angular momentum l f = 0.1. As a first step to improve the coupled-states model, a computer program was developed to calculate the matrix elements of the Coulomb interaction between a charged particle and an atomic electron, ∫ ψ* f (r) /R - r/ -1 ψ i (r)dr, for arbitrary final state energy E f and angular momentum l f . The ψ k (r)'s are non-relativistic hydrogenic wave functions. The program consists of subroutines that compute matrix elements between eigenstates of both the total angular momentum j, and the orbital angular momentum l. As further output quantities, the radial components of the multipole series expansion of the matrix elements (the so-called G functions) can be obtained, as well. The structure of the program is such that the hydrogenic wave functions can be replaced by arbitrary one-electron wave functions. The program was tested in calculations of K-, L- and M-shell ionization probabilities and cross sections within the framework of the straight-line version of the (first-order) semiclassical

  15. Theoretical calculation (DFT), Raman and surface-enhanced Raman scattering (SERS) study of ponceau 4R

    Science.gov (United States)

    Xie, Yunfei; Li, Yan; Sun, Yingying; Wang, Heya; Qian, He; Yao, Weirong

    2012-10-01

    Ponceau 4R is used as a coloring agent in many different products, such as food, drinks, medicines, cosmetics and tobacco. However, ponceau 4R also shows carcinogenic, teratogenic and mutagenic behavior in high doses. In this work, standard Raman, theoretical Raman and surface-enhanced Raman scattering (SERS) spectra have been used to investigate ponceau 4R. More specifically, density functional theory (DFT) calculations have been used to calculate the optimized Raman spectrum of ponceau 4R at the B3LYP/6-31G(d) level. This has provided a better understanding of the optimized geometry and vibrational frequencies of this dye. In addition, the experimental spectrum of ponceau 4R has been compared with the theoretical spectrum; good agreement was obtained. Finally, it has shown that using SERS the detection limit of the ponceau 4R solution can be as low as 5 μg/mL. This has been achieved by SERS measurements of ponceau 4R on a substrate of gold nanoparticles. The SERS peaks at 1030, 1236, 1356 and 1502 cm-1 were chosen as index for semi-quantitative analysis, showing that the SERS technique provided a useful ultrasensitive method for the detection of ponceau 4R.

  16. Theoretical studies on the mechanical behavior of granular materials under very low intergranular stresses

    Science.gov (United States)

    French, Kenneth W., Jr.

    1986-01-01

    The salient aspects of the theoretical modeling of a conventional triaxial test (CTC) of a cohesionless granular medium with stress and strain rate loading are described. Included are a controllable gravitational body force and provision for low confining pressure and/or very low intergranular stress. The modeling includes rational, analytic, and numerical phases, all in various stages of development. The numerical evolutions of theoretical models will be used in final design stages and in the analysis of the experimental data. In this the experimental design stage, it is of special interest to include in the candidate considerations every anomaly found in preliminary terrestrial experimentation. Most of the anomalies will be eliminated by design or enhanced for measurement as the project progresses. The main aspect of design being not the physical apparatus but the type and trajectories of loading elected. The major considerations that have been treated are: appearance and growth of local surface aberrations, stress-power coefficients, strain types, optical strain, radial bead migration, and measures of rotation for the proper stress flux.

  17. Wave propagation in bubble, two-component, two-phase flows. Theoretical and experimental study

    International Nuclear Information System (INIS)

    Micaelli, Jean-Claude

    1982-01-01

    This research thesis first reports the theoretical study of pressure and vacuum rate waves (of low amplitude) propagating through two-phase flows. This study is performed by using hybrid models. These models, based on assessment equations averaged for each phase, are developed by using a stochastic processing of the gas phase behaviour. This stochastic processing allows the model closure. The author highlights, in the case of vacuum rate waves, the importance of mass effects, interface friction and interface heat transfer. An experimental study is performed by using a vertical test section equipped with resistive probes and pressure sensors, and a signal processing unit (Fourier transform, inter-spectrum). Experimental results are confirmed by theoretical results, and leads to quantitative information on laws governing the interaction between phases which are necessary for model closure [fr

  18. Theoretical and experimental study of an energy-reinforced braking radiation photon beam

    International Nuclear Information System (INIS)

    Bertin, Pierre-Yves

    1966-01-01

    This research thesis reports the theoretical study of a photon beam raised towards high energies, its experimental implementation, the definition of a gamma spectrometry method which aimed at checking various hypotheses used in the beam theoretical study. After a presentation of the theory of phenomena of electron braking radiation, of materialisation of photons into positon-negaton pair, and of issues related to multiple Coulomb diffusion, the author reports the study of the different solutions which allow a photon beam to be obtained. A braking radiation of mono-kinetic electron has been used. This braking radiation is reinforced by absorption of low energy protons in a column of lithium hydride. The author describes how the beam is built up, and the experimental approach. He describes how raw data are processed to get rid of the influence of the multiple Coulomb diffusion and of the braking radiation. Experimental results are compared with those obtained by convolution of photon spectra and differential cross section

  19. Ripeness sensor development. Final report of a Phase 2 study

    Energy Technology Data Exchange (ETDEWEB)

    Stroshine, R.

    1995-08-01

    This is a final report for the Phase II study entitled ``Ripeness Sensor Development.`` The overall objective of the study was the development of a prototype device capable of testing whole fruits for sugar content. Although ripeness and sugar content are not synonymous, they are closely related. Furthermore, the consumer`s acceptance of or preference for fruits is strongly influenced by sugar content. Therefore, the device was called a ripeness sensor. The principle behind the measurement is proton magnetic resonance ({sup 1}H-MR). For several decades, chemists, pharmacists and other scientists have been using {sup 1}H-MR to investigate chemical structure and composition. More recently, the technique has been used in laboratories of the food industry for quality control. This effort represents one of the first attempts to adapt {sup 1}H-MR to use in a commercial facility. 28 refs., 36 figs., 7 tabs.

  20. Study of $\\pi^{-}p$ interactions with neutral final states

    CERN Multimedia

    2002-01-01

    This experiment is a study of the production of neutral particles or states decaying into photons in the reaction $\\pi^{-} + p \\rightarrow M^{0} + n$ at SPS energies. \\\\ \\\\ Special attention is paid to the measurement of the production of heavy particles with hidden quantum numbers and of possible new heavy spinless states decaying into two photons. \\\\ \\\\ The large four-momentum transfer behaviour of binary processes involving known neutral mesons and the production of new meson resonances with high mass and spin will also be studied. Complex multiparticle final states will be analysed as a by-product.\\\\ \\\\ The central unit of the experimental set-up is a 4000 cell Cerenkov hodoscope spectrometer (GAMS) which allows the measurement of the momentum vector of each $\\gamma$ in a multigamma event. \\\\ \\\\ The longitudinal position of the interaction point in the liquid hydrogen target is measured by the Cerenkov light intensity. \\\\ \\\\ A guard system, made of scintillation counters and lead-glass Cerenkov counters, ...

  1. Study of electron and neutrino interactions. Final report

    International Nuclear Information System (INIS)

    Abashian, A.

    1997-01-01

    This is the final report for the DOE-sponsored experimental particle physics program at Virginia Tech to study the properties of the Standard Model of strong and electroweak interactions. This contract (DE-AS05-80ER10713) covers the period from August 1, 1980 to January 31, 1993. Task B of this contract, headed by Professor Alexander Abashian, is described in this final report. This program has been pursued on many fronts by the researchers in a search for axions at SLAC, in electron-positron collisions in the AMY experiment at the TRISTAN collider in Japan, in measurements of muon decay properties in the MEGA and RHO experiments at the LAMPF accelerator, in a detailed analysis of scattering effects in the purported observation of a 17 keV neutrino at Oxford, in a search for a disoriented chiral condensate with the MiniMax experiment at Fermilab, and in an R ampersand D program on resistive plate counters that could find use in low-cost high-quality charged particle detection at low rates

  2. Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Moral, Monica; Garcia, Gregorio [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Penas, Antonio [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Garzon, Andres; Granadino-Roldan, Jose M. [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Melguizo, Manuel [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Fernandez-Gomez, Manuel, E-mail: mfg@ujaen.es [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer We study properties of Ph{sub 2}Tz and (PhTz){sub n}Ph as candidates for organic electronics. Black-Right-Pointing-Pointer The synthesis of Ph{sub 2}Tz was performed through a modified Pinner-type reaction. Black-Right-Pointing-Pointer IR/Raman spectra allowed to conclude that Ph{sub 2}Tz is nearly planar in liquid phase. Black-Right-Pointing-Pointer Electronic structure was studied by UV-Vis/TD-DFT methods in different solvents. Black-Right-Pointing-Pointer Bandgap, E{sub LUMO}, electron mobility predict some n-type character for limit polymer. -- Abstract: This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph{sub 2}Tz) and some oligomeric derivatives. Ph{sub 2}Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV-Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

  3. A theoretical study of rotatable renewable energy system for stratospheric airship

    International Nuclear Information System (INIS)

    Lv, Mingyun; Li, Jun; Zhu, Weiyu; Du, Huafei; Meng, Junhui; Sun, Kangwen

    2017-01-01

    Highlights: • A new rotatable renewable energy system is designed for stratospheric airship. • A theoretical model of optimal rotation angle and required area are studied. • The effects of latitude and date on output energy per day are investigated. • The advantages of the rotatable renewable energy system are studied. - Abstract: Renewable energy system is very critical for solving the energy problem of a long endurance stratospheric airship. Output performance of the traditional solar array fixed on the upper surface of the airship remains to be improved to reduce the area and weight of renewable energy system. Inspired by the solar tracking system and kirigami, a rotatable renewable energy system (mainly including solar array) is designed to improve the current status of the energy system. The advantages of the rotatable solar array are studied using a MATLAB computer program based on the theoretical model established in this paper. The improvements in output energy and required area of the solar array were compared between the traditional airship and improved one. Studies had shown that the rotatable renewable energy system made the total weight of energy system decreased by 1000 kg when the maximum design speed of the airship was greater than 22 m/s. The results demonstrate that the rotatable renewable energy system for the airship can be a good way to improve the output performance of solar array, and the conceptual design and theoretical model suggest a pathway towards solving the energy problem of a stratospheric airship.

  4. Theoretical model simulations for the global Thermospheric Mapping Study (TMS) periods

    Science.gov (United States)

    Rees, D.; Fuller-Rowell, T. J.

    Theoretical and semiempirical models of the solar UV/EUV and of the geomagnetic driving forces affecting the terrestrial mesosphere and thermosphere have been used to generate a series of representative numerical time-dependent and global models of the thermosphere, for the range of solar and geoamgnetic activity levels which occurred during the three Thermospheric Mapping Study periods. The simulations obtained from these numerical models are compared with observations, and with the results of semiempirical models of the thermosphere. The theoretical models provide a record of the magnitude of the major driving forces which affected the thermosphere during the study periods, and a baseline against which the actual observed structure and dynamics can be compared.

  5. RECENT DEVELOPMENTS OF THE FINANCIAL REPORTING MODEL: THEORETICAL STUDIES IN REVIEW

    OpenAIRE

    Bonaci Carmen Giorgiana; Matis Dumitru

    2011-01-01

    Our paper analyzes the manner in which the financial reporting model evolved towards fair value accounting. After a brief introduction into the context of financial reporting at international level, the analysis focuses on the accounting model of fair value. This is done by synthesizing main studies in accounting research literature that analyze fair value accounting through a theoretical approach. The analysis being developed relies on literature review methodology. The main purpose of the d...

  6. Isolation, spectroscopic characterization, X-ray, theoretical studies as well as in vitro cytotoxicity of Samarcandin

    Czech Academy of Sciences Publication Activity Database

    Ghoran, S.H.; Atabaki, V.; Babaei, E.; Olfatkhah, S.R.; Dušek, Michal; Eigner, Václav; Soltani, A.; Khalaji, A.D.

    2016-01-01

    Roč. 66, Jun (2016), s. 27-32 ISSN 0045-2068 R&D Projects: GA ČR GA15-12653S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : cytotoxicity * NMR * sesquiterpene coumarin * theoretical study * TD-DFT * X-ray Subject RIV: CC - Organic Chemistry Impact factor: 3.231, year: 2016

  7. Theoretical studies on the α decay half-lives of hyper and normal ...

    Indian Academy of Sciences (India)

    The α decay half-lives of hyper and normal isotopes of Po nuclei are studied in the present work. The inclusion of Λ – N interaction changes the half-life for α decay. The theoretical predictions on the α decay half-lives of normal Po isotopes are compared with experimental results and are seen to be matching well with each ...

  8. Theoretical Studies of TE-Wave Propagation as a Diagnostic for Electron Cloud

    International Nuclear Information System (INIS)

    Penn, Gregory E.; Vay, Jean-Luc

    2010-01-01

    The propagation of TE waves is sensitive to the presence of an electron cloud primarily through phase shifts generated by the altered dielectric function, but can also lead to polarization changes and other effects, especially in the presence of magnetic fields. These effects are studied theoretically and also through simulations using WARP. Examples are shown related to CesrTA parameters, and used to observe different regimes of operation as well as to validate estimates of the phase shift.

  9. Theoretical and experimental study of the instabilities of air-lift pumping systems

    International Nuclear Information System (INIS)

    Cachard, Francois de

    1989-01-01

    Air-lifts are pumping systems which operate by air injection into the conduct containing the fluid to be transferred. They are notably used for corroding or radioactive liquids. Their instabilities which result in highly pulsed flows, do not comply with many applications. This research thesis reports a theoretical and experimental study which aimed at developing a numeric modelling which can be a practical tool to analyse air-lift performance and stability [fr

  10. Contribution to the theoretical study of metallic systems containing rare earths: hyperfine interactions and exchange coupling

    International Nuclear Information System (INIS)

    Troper, A.

    1978-01-01

    A theoretical study involving rare earth impurities, which were embedded in transition metals (s-p or noble), from the point of view of the hyperfine interactions is presented. A model was created to describe a d-resonance (Anderson-Moriya) acting on a s-p conduction band which was strongly perturbed by a slater-koster potential, used to describe the rare earths which were diluted in matrices of transition elements. (author)

  11. The mechanism for the rhodium-catalyzed decarbonylation of aldehydes: A combined experimental and theoretical study

    DEFF Research Database (Denmark)

    Fristrup, Peter; Kreis, Michael; Palmelund, Anders

    2008-01-01

    that similar mechanisms are operating. A DFT (B3LYP) study of the catalytic cycle indicated a rapid oxidative addition into the C(O)-H bond followed by a rate-limiting extrusion of CO and reductive elimination. The theoretical kinetic isotope effects based on this mechanism were in excellent agreement...... with the experimental values for both substrates, but only when migratory extrusion of 00 was selected as the rate-determining step....

  12. Theoretical study on ground-state proton/H-atom exchange in formic ...

    Indian Academy of Sciences (India)

    Theoretical study on ground-state proton/H-atom exchange in formic acid clusters through different H-bonded .... the pKa of the proton wire, faster is the rate of proton transfer. It is obvious that the features of the H- ..... tances in TS could be ascribed to the higher basicity (as. Table 4. Mulliken partial charges of selected atoms ...

  13. High Performance Computer Cluster for Theoretical Studies of Roaming in Chemical Reactions

    Science.gov (United States)

    2016-08-30

    High-performance Computer Cluster for Theoretical Studies of Roaming in Chemical Reactions A dedicated high-performance computer cluster was...purchased in order to carry out extensive and state-of-the art computations of chemical reaction dynamics. The specific aim of this computational research...is the detailed elucidation of the recently reported “roaming” pathway in gas-phase chemical reactions . Several complex reaction systems

  14. Annual Report 2013-2014: Theoretical Studies of Nerve Agents Adsorbed on Surfaces

    Science.gov (United States)

    2014-07-08

    Photoassisted removal of sarin vapor in air under UV light irradiation. Journal of Photochemistry and Photobiology a- Chemistry 2007, 188, 143-148...with an ester linkage to an aliphatic group. Coloring scheme as follows: C (gray), H (white), O (red), P (orange), F ( blue ). Most nerve agents act...magnesium oxide. Journal of Physical Chemistry B 2004, 108, 5294-5303. 7. Michalkova, A.; Paukku, Y .; Majumdar, D.; Leszczynski, J., Theoretical study

  15. Theoretical and Computational Studies of Rare Earth Substitutes: A Test-bed for Accelerated Materials Development

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Lorin X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    Hard permanent magnets in wide use typically involve expensive Rare Earth elements. In this effort, we investigated candidate permanent magnet materials which contain no Rare Earths, while simultaneously exploring improvements in theoretical methodology which enable the better prediction of magnetic properties relevant for the future design and optimization of permanent magnets. This included a detailed study of magnetocrystalline anisotropy energies, and the use of advanced simulation tools to better describe magnetic properties at elevated temperatures.

  16. Theoretical studies on the decay half-lives of hyper and normal ...

    Indian Academy of Sciences (India)

    K P SANTHOSH

    2018-02-10

    Feb 10, 2018 ... Abstract. The α decay half-lives of hyper and normal isotopes of Po nuclei are studied in the present work. The inclusion of –N interaction changes the half-life for α decay. The theoretical predictions on the α decay half-lives of normal Po isotopes are compared with experimental results and are seen to be ...

  17. Critical Parametric Study on Final Size of Magnetite Nanoparticles

    Science.gov (United States)

    Yusoff, A. H. M.; Salimi, M. N.; Jamlos, M. F.

    2018-03-01

    The great performance of magnetite nanoparticle in varsity field are mainly depended on their size since size determine the saturation magnetisation and also the phase purity. Magnetite nanoparticles were prepared using a simple co-precipitation method in order to study the influence of synthesis condition on the final size. Variable parameters include stirring rate, reaction temperature and pH of the solution can finely tuned the size of the resulting nanoparticles. Generally, any increase in these parameters had a gently reduction on particle size. But, the size was promoted to increase back at certain point due to the specific reason. Nucleation and growth processes are involved to clarify the impact of synthesis condition on the particle sizes. The result obtained give the correct conditions for pure magnetite synthesis at nanoscale size of dimensions less than 100 nm.

  18. Spectral absorption studies of visible materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bass, M.; Swimm, R.T.

    1986-01-01

    Results of studies of optical absorption in twelve thin-film optical coatings at 482 nm wavelength, surface and bulk absorption in sapphire throughout the visible and near IR, and initial measurements in KDP are described. Laser calorimetry was carried out at room temperature, using an unfocused laser beam at normal incidence. All thin-film absorption data yielded values of P/sub abs//P/sub inc/ in the range 3 x 10 U to 3 x 10 T at a wavelength of 482 nm. Sapphire absorption showed Urbach-tail behavior at 350 nm to 1300 nm. The range of absorption, being far lower than usual, extends the range of application of Urbach's rule. Finally, KDP measurements were attempted, but surface degradation due to the hydroscopic nature of the samples resulted in excessive light scatter.

  19. Theoretical and experimental study of inverted annular film boiling and regime transition during reflood transients

    Science.gov (United States)

    Mohanta, Lokanath

    from single tube experiments. The root mean square error in predicting the FLECHT-SEASET data is 20% whereas for single tube data it is 12%. In previous studies, the transition criterion from the IAFB to the ISFB regime is purely empirical. In this work, a theoretical stability analysis of a liquid jet co-flowing with its vapor in a tube is carried out to seek a better understanding of the underlying physics of the regime transition. The effect of heat and mass transfer at the interface is included in the stability analysis. Also, the effect of viscous force is included in the stability analysis, by employing the viscous potential flow method. The wavelength that is responsible for breakup of the liquid core in IAFB is predicted in the present analysis and is compared with the adiabatic experiments of IAFB from the literature. The effects of various controlling parameters including the relative Weber number, vapor Reynolds number, velocity ratio, density ratio and viscosity ratio of vapor and liquid are studied to understand the physics of transition. Finally a physics-based heat transfer model is proposed for heat transfer in the ISFB regime using the wavelength obtained from the stability analysis. Keywords: Inverted annular film boiling, Two-phase heat transfer, Subcooled flow film boiling, Inverted slug film boiling, Regime transition, Void fraction in post CHF regime, Rod bundle, Spacer grid, Stability, Two-phase flow, Kelvin-Helmholtz instability, Capillary instability, Co-axial jets, Viscous potential flow, Interfacial heat and mass transfer.

  20. Theoretical study of the lowest-lying electronic states of Aluminium monoiodide

    International Nuclear Information System (INIS)

    Taher, F.; Kabbani, A.; Ani-El Houte, W.

    2004-01-01

    Full text.The spectroscopic study of Aluminium monohalides, especially the Aluminium monoiodide, is important for monitoring such species in high temperature fast-flow reactors. Theoretical calculations of AlI are not available, whereas several studies have been done for the other aluminium monohalides. In this work, CAS-SCF/MRCI calculations are performed for the lowest-lying electronic states of AlI in a range of internuclear distance between 2.30 A and 2.80 A. Ab-initio calculations have been effectuated by using the computational chemistry program Molpro. The basis set used in this study for aluminium atom is that used by Langhoff for aluminium monohalides, of contractions using atomic natural orbitals and a pseudopotential is used for iode. Accurate theoretical spectroscopic constants and potential curves are obtained for the ground state X 1 Σ + and the first excited states a 3 Π and A 1 Π. The calculated values of Te, ωe, ωexe and re of these states are compatible with the experimental results. An ordering of states is represented for the lowest five predicted singlet and lowest five predicted triplet states. These results provide a big support to determine the analogy in the ordering of the electronic states in AlF, AlBr and AlI respectively at lower energies. These theoretical results identify a set of electronic singlet and triplet states unobserved experimentally

  1. Synthesis, characterization, investigation of biological activity and theoretical studies of hydrazone compounds containing choloroacetyl group

    Science.gov (United States)

    Cukurovali, Alaaddin; Yilmaz, Engin

    2014-10-01

    In this study, three new hydrazide-hydrazone derivative compounds which contain choloroacetyl group have been synthesized and characterized. In the characterization, spectral techniques such as IR, 1H NMR, 13C NMR and UV-Vis spectroscopy techniques were used. Antibacterial effects of the synthesized compounds were investigated against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. In the theoretical calculations Gaussian 09 software was used with the DFT/6-311+(d,p) basis set. Experimental X-ray analysis of compounds has not been studied. Theoretical bond lengths of synthesized compounds were compared with experimental bond lengths of a similar compound. Theoretical and experimental bond lengths are in good agreement with R2: 0.896, 0.899 and 0.900 for compounds 1, 2, and 3, respectively. For antibacterial activity, the most effective one was found to be N‧-(4-bromobenzylidene)-2-chloro-N-(4-(3-methyl-3-phenylcyclobutyl)-thiazol-2-yl) acetohydrazide against P.aeroginaosa ATTC 27853, among the studied compounds.

  2. Anatomy studies for an artificial heart. Final summary report

    Energy Technology Data Exchange (ETDEWEB)

    Kiraly, R.J.; Nose, Y.

    1977-12-01

    In the interval from February of 1972 through December of 1977, studies were conducted relating to the anatomical feasibility of implanting a total artificial heart system. These studies included both the calf as an experimental animal as well as the ultimate human recipient of the artificial heart system. Studies with the calf included definition of the thoracic anatomy relative to the size, shape, and vascular connections for implanting the blood pump. To test the animal's tolerance to an implanted engine system, mockups of the thermal converter were implanted chronically in various locations within the calf. No problems developed in retroperitoneal or intraperitoneal implants ranging from 8 to 15 months. A study to determine accelerations experienced by an abdominally implanted thermal converter was performed in calves. Under the most severe conditions, accelerations of a maximum of 34 Gs were experienced. The largest effort was devoted to defining the human anatomy relative to implanting an artificial heart in the thorax. From a number of data sources, including cadavers as well as living patients, a quantitative, statistical analysis of the size and shape of the male thorax was obtained. Finally, an in vivo study of a functional intrathoracic compliance bag in a calf demonstrated the feasibility of this method.

  3. Anatomy studies for an artificial heart. Final summary report

    International Nuclear Information System (INIS)

    Kiraly, R.J.; Nose, Y.

    1977-12-01

    In the interval from February of 1972 through December of 1977, studies were conducted relating to the anatomical feasibility of implanting a total artificial heart system. These studies included both the calf as an experimental animal as well as the ultimate human recipient of the artificial heart system. Studies with the calf included definition of the thoracic anatomy relative to the size, shape, and vascular connections for implanting the blood pump. To test the animal's tolerance to an implanted engine system, mockups of the thermal converter were implanted chronically in various locations within the calf. No problems developed in retroperitoneal or intraperitoneal implants ranging from 8 to 15 months. A study to determine accelerations experienced by an abdominally implanted thermal converter was performed in calves. Under the most severe conditions, accelerations of a maximum of 34 Gs were experienced. The largest effort was devoted to defining the human anatomy relative to implanting an artificial heart in the thorax. From a number of data sources, including cadavers as well as living patients, a quantitative, statistical analysis of the size and shape of the male thorax was obtained. Finally, an in vivo study of a functional intrathoracic compliance bag in a calf demonstrated the feasibility of this method

  4. Final focus system tuning studies towards Compact Linear Collider feasibility

    Directory of Open Access Journals (Sweden)

    E. Marin

    2018-01-01

    Full Text Available In this paper we present the latest results regarding the tuning study of the baseline design of the final focus system of the Compact Linear Collider (CLIC-FFS. CLIC aims to provide collisions to the experiments at a luminosity above 10^{34}  cm^{-2} s^{-1}. In order to deliver such luminosity in a single pass machine, the vertical beam size at the interaction point (IP is reduced to about 1 nm, which imposes unprecedented tuning difficulties to the system. In previous studies, 90% of the machines reached 90% of the nominal luminosity at the expense of 18 000 luminosity measurements, when considering beam position monitor errors and transverse misalignments of magnets for a single beam case. In the present study, additional static imperfections such as roll misalignments and strength errors are included. Moreover both e^{-} and e^{+} beamlines are properly simulated. A new tuning procedure based on linear and nonlinear knobs is implemented to effectively cure the most relevant beam size aberrations at the IP. The obtained results for single and double beam studies under solely static imperfections are presented.

  5. Final focus system tuning studies towards Compact Linear Collider feasibility

    Science.gov (United States)

    Marin, E.; Latina, A.; Tomás, R.; Schulte, D.

    2018-01-01

    In this paper we present the latest results regarding the tuning study of the baseline design of the final focus system of the Compact Linear Collider (CLIC-FFS). CLIC aims to provide collisions to the experiments at a luminosity above 1034 c m-2 s-1 . In order to deliver such luminosity in a single pass machine, the vertical beam size at the interaction point (IP) is reduced to about 1 nm, which imposes unprecedented tuning difficulties to the system. In previous studies, 90% of the machines reached 90% of the nominal luminosity at the expense of 18 000 luminosity measurements, when considering beam position monitor errors and transverse misalignments of magnets for a single beam case. In the present study, additional static imperfections as, roll misalignments, strength v2.epss are included. Moreover both e- and e+ beamlines are properly simulated. A new tuning procedure based on linear and nonlinear knobs is implemented to effectively cure the most relevant beam size aberrations at the IP. The obtained results for single and double beam studies under solely static imperfections are presented.

  6. FEELINGS OF INSECURITY IN CONTEXT: THEORETICAL PERSPECTIVES FOR STUDYING FEAR OF CRIME IN LATE LIFE

    Directory of Open Access Journals (Sweden)

    Liesbeth De Donder

    2009-01-01

    Full Text Available This paper broadens theoretical perspectives on fear of crime in late life by exploring the concept against the backdrop of a changing society. Since the emergence of the first studies that address fear of crime in late life, research overemphasizes the search for related independent variables being heedless of a thorough theoretical framework. Recent researchers, however, perceive the construct of ‘fear of crime’ as an ‘umbrella’ concept, which encompasses crime related fear and more diffuse ‘feelings of insecurity’. In response to a lack of macro-theorizing, this article illuminates some of the most important characteristics and descriptions of contemporary societies that are relevant to fear of crime. It is shown that in relation to fear of crime, the macro-level of society can be conceptualized as having four important ambivalences. In conclusion, the article

  7. Spin-dependent Hall effect in degenerate semiconductors: a theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Idrish Miah, M [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)], E-mail: m.miah@griffith.edu.au

    2008-10-15

    The spin-dependent Hall (SDH) effect in degenerate semiconductors is investigated theoretically. Starting from a two-component drift-diffusion equation, an expression for SDH voltage (V{sub SDH}) is derived, and drift and diffusive contributions to V{sub SDH} are studied. For the possible enhancement of the diffusive part, degenerate and nondegenerate cases are examined. We find that due to an increase in the diffusion coefficient V{sub SDH} increases in a degenerate semiconductor, consistent with the experimental observations. The expression for V{sub SDH} is reduced in three limiting cases, namely diffusive, drift-diffusion crossover and drift, and is analysed. The results agree with those obtained in recent theoretical investigations.

  8. Theoretical and experimental study of collectrons for epithermal neutron flux in reactors

    International Nuclear Information System (INIS)

    Agu, M.N.

    1986-01-01

    A theoretical study of nuclear reactions and electric charge displacements arising in sensitivity to thermal and epithermal neutrons in collectrons allowed a computer code conception. Collectrons in Rhodium, Silver, Cobalt, Hafnium, Erbium, Gadolinium and Holmium have been tested in different radiation fields given by neutron or gamma filters irradiated in different places of Melusine and Siloe reactors. Some emitters were covered with different steel, nickel or zircaloy thicknesses. Theoretical and experimental results are consistent; that validate the computer code and show possibilities and necessity of covering collectron emitters to reduce or cancel the gamma sensitivity and to improve response instantaneity. A selective measurement of epithermal neutron flux can by this way, made by associating two types of collectrons [fr

  9. Thermodynamic properties and equilibrium constant of chemical reaction in nanosystem: An theoretical and experimental study

    International Nuclear Information System (INIS)

    Du, Jianping; Zhao, Ruihua; Xue, Yongqiang

    2012-01-01

    Highlights: ► There is an obvious influence of the size on thermodynamic properties for the reaction referring nano-reactants. ► Gibbs function, enthalpy, entropy and equilibrium constant are dependent on the reactant size. ► There is an approximate linear relation between them. - Abstract: The theoretical relations of thermodynamic properties, the equilibrium constant and reactant size in nanosystem are described. The effects of size on thermodynamic properties and the equilibrium constant were studied using nanosize zinc oxide and sodium bisulfate solution as a reaction system. The experimental results indicated that the molar Gibbs free energy, the molar enthalpy and the molar entropy of the reaction decrease, but the equilibrium constant increases with decreasing reactant size. Linear trends were observed between the reciprocal of size for nano-reactant and thermodynamic variable, which are consistent with the theoretical relations.

  10. Theoretical Studies of Structure, Spectroscopy, and Properties of a New Hydrazine Derivative

    Directory of Open Access Journals (Sweden)

    Hajar Sahebalzamani

    2013-01-01

    Full Text Available We will report a combined experimental and theoretical study on molecular structure, vibrational spectra, and energies of (E-1-(2,4-dinitrophenyl-2-[(4-methylphenylmethylidene]hydrazine (1. The molecular geometry and vibrational frequencies and energies in the ground state are calculated by using HF and DFT levels of theory with 6-311G basis sets. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The harmonic vibrational frequencies were calculated, and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed bar-type spectrograms.

  11. A theoretical and experimental EPFM study of cracks emanating from a hole

    International Nuclear Information System (INIS)

    Broekhoven, M.J.G.

    1978-01-01

    Results are presented of a combined theoretical and experimental study on the onset of crack extension in the EPFM regime for through cracks emanating from a circular hole in a plate under tensile load, with emphasis on the applicability of the J-concept for predicting such extensions. This configuration was selected both because of its general importance and as a first approximation for a nozzle-to-vessel geometry. Theoretical investigations consisted of elastic-plastic finite element computations both for 3-point bend specimens and for plate geometry. J values were calculated using the contour-integral definition for J, and by the method of virtual crack extension. The applicability of simplified analytical approximations for J was also investigated. COD data were derived from finite element computed displacements. Experimental investigations included Jsub(Ic) tests on a series of bend specimens and crack extensions tests on a series of cracked perforated plate models. For practical reasons aluminium 2024-T 351 was selected as a suitable model material within the aims of the study. Onset of crack extension was determined by the heat-tinting procedure throughout the experiments, in some cases supplemented by fractographic investigations. The various theoretical solutions and experimental observations were compared and a number of conclusions were drawn. (author)

  12. Theoretical and experimental NMR studies on muscimol from fly agaric mushroom (Amanita muscaria)

    Science.gov (United States)

    Kupka, Teobald; Wieczorek, Piotr P.

    2016-01-01

    In this article we report results of combined theoretical and experimental NMR studies on muscimol, the bioactive alkaloid from fly agaric mushroom (Amanita muscaria). The assignment of 1H and 13C NMR spectra of muscimol in DMSO-d6 was supported by additional two-dimensional heteronuclear correlated spectra (2D NMR) and gauge independent atomic orbital (GIAO) NMR calculations using density functional theory (DFT). The effect of solvent in theoretical calculations was included via polarized continuum model (PCM) and the hybrid three-parameter B3LYP density functional in combination with 6-311++G(3df,2pd) basis set enabled calculation of reliable structures of non-ionized (neutral) molecule and its NH and zwitterionic forms in the gas phase, chloroform, DMSO and water. GIAO NMR calculations, using equilibrium and rovibrationally averaged geometry, at B3LYP/6-31G* and B3LYP/aug-cc-pVTZ-J levels of theory provided muscimol nuclear magnetic shieldings. The theoretical proton and carbon chemical shifts were critically compared with experimental NMR spectra measured in DMSO. Our results provide useful information on its structure in solution. We believe that such data could improve the understanding of basic features of muscimol at atomistic level and provide another tool in studies related to GABA analogs.

  13. System study of alternative waste management techniques: Final report

    International Nuclear Information System (INIS)

    1986-01-01

    This report summarizes the important results achieved in conjunction with the Research and Development Priority ''Alternative Waste Management Techniques'' sponsored by the Federal Ministry of Research and Technology from 1981 to 1984. The subject of these studies was solely ''direct disposal'' of spent fuel elements. For this purpose a reference concept was selected from a variety of possible processes and engineered in detailed form by firms in the nuclear industry. Those who worked on the engineering concepts consider this waste management method technically feasible. Several disposal casks have been fabricated. The basic licensability of direct disposal can be evaluated on the basis of the documentation developed by the companies. The direct disposal method was compared with the ''integrated waste management concept'' using reference fuel cycles with respect to the following criteria: radiological safety and nuclear material safeguards and, in addition, economic and energy-policy aspects. It was found that with respect to radiological safety, including the long-term safety of the final repository, there are no significant differences between the two fuel cycles with and without reprocessing. With respect to the nuclear material safeguards of a final repository containing spent fuel elements, there are still a number of unanswered questions. From an economic standpoint, direct disposal will be more economical in the foreseeable future than integrated waste management. Quantification of the effects of one or the other waste management method on the national economy is not necessarily possible. Reprocessing is supported primarily by technological and energy-policy considerations. On the basis of the results, the conclusion is reached that reprocessing should be pursued further, but that at the same time direct disposal should be developed to the point of practical maturity

  14. Final report for the year 2001 on experimental and theoretical investigations of irradiation effects on physical and mechanical properties of iron and RAFM steels

    International Nuclear Information System (INIS)

    Singh, B.N.

    2003-08-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties have been studied both experimentally and theoretically. Specimens of pure iron and RAFM (reduced activation ferritic-martensic) steels were irradiated to different dose levels and at different irradiation temperatures. The resulting microstructure was characterized using transmission electron microscopy, positron annihilation spectroscopy and electrical resistivity measurements. Mechanical properties were determined by uniaxial tensile testing. Dislocation-loop interaction, formation of rafts of loops, radiation hardening and formation of 'cleared channels' were studied using different computational techniques. Experiments have shown that nano-voids are formed both in pure iron and F82H steel already at 50 deg. C. In pure iron, the formation of nano-voids is detected already at a dose level of ∼10 -3 dpa. Also in iron, self-interstitial atoms were found to accumulate in the form of glissile and sessile loops; at higher dose levels, these loops led to formation of rafts of loops. Irradiation led to an increase in the yield strength, a sudden drop in the yield stress, and, at higher doses, the initiation of plastic instability immediately beyond the upper yield point. Experimental as well as the results of computer simulations are found to be consistent with the cascade induced source hardening model

  15. Final report for the year 2001 on experimental and theoretical investigations of irradiation effects on physical and mechanical properties of iron and RAFM steels

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.N

    2003-08-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties have been studied both experimentally and theoretically. Specimens of pure iron and RAFM (reduced activation ferritic-martensic) steels were irradiated to different dose levels and at different irradiation temperatures. The resulting microstructure was characterized using transmission electron microscopy, positron annihilation spectroscopy and electrical resistivity measurements. Mechanical properties were determined by uniaxial tensile testing. Dislocation-loop interaction, formation of rafts of loops, radiation hardening and formation of 'cleared channels' were studied using different computational techniques. Experiments have shown that nano-voids are formed both in pure iron and F82H steel already at 50 deg. C. In pure iron, the formation of nano-voids is detected already at a dose level of {approx}10{sup -3} dpa. Also in iron, self-interstitial atoms were found to accumulate in the form of glissile and sessile loops; at higher dose levels, these loops led to formation of rafts of loops. Irradiation led to an increase in the yield strength, a sudden drop in the yield stress, and, at higher doses, the initiation of plastic instability immediately beyond the upper yield point. Experimental as well as the results of computer simulations are found to be consistent with the cascade induced source hardening model.

  16. A theoretical study on the photoionization of the valence orbitals of phosphine

    Directory of Open Access Journals (Sweden)

    Nascimento Edmar M.

    2006-01-01

    Full Text Available We report a theoretical study on the photoionization of phosphine in the static-exchange level and frozen core approximation, using the method of continued fractions. The main subject of the present study is to investigate in which extent the Hartree-Fock description of the target applied to molecular photoionization is valid. Also, the role played by multichannel coupling is analysed. Our study shows that single-channel Hartree-Fock calculations can provide reliable results except for photon energies near the photoionization threshold.

  17. Density Functional Theoretical and Time-dependent Density Functional Theoretical Study on Thiophene.Benzothiadiazole-based Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Wo, Han Young; Uddin, Mohammad Afsar; Hwang, Sungu Hwang [Pusan National University, Busan (Korea, Republic of)

    2015-01-15

    In order to improve the performance of the photovoltaic cell, much effort has been dedicated in terms of the design of new materials, device architectures, and processing techniques. In the design of new molecular structure of the repeat unit, electronic properties such as the highest occupied molecular orbital (HOMO) level and bandgap are important because they are related to the efficiency of the photovoltaic cell. A quantitative prediction of these electronic properties prior to the actual synthesis would be of great help by minimizing the effort of trial-and-error synthesis. Recently, we reported the molecular design and photovoltaic property relationships of low bandgap polymer based on a thiophene (T).benzothiadiazole (BT) alternating structure. DFT and TD-DFT calculations were applied to six different T.BT units. Torsional profile studies showed that the presence of the alkoxy linkage provides ring coplanarity, which leads to good π-π packing between two chains. Quantitative studies on the HOMO and bandgap of the polymers show excellent correlation between the experimental results and the DFT calculations.

  18. Theoretical and Experimental Studies of Wave Impact underneath Decks of Offshore Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Baarholm, Rolf Jarle

    2001-07-01

    The main objective of this thesis has been to study the phenomenon of water impact underneath the decks of offshore platforms due to propagating waves. The emphasis has been on the impact loads. Two theoretical methods based on two-dimensional potential theory have been developed, a Wagner based method (WBM) and a nonlinear boundary element method (BEM). A procedure to account for three-dimensional effects is suggested. The deck is assumed to be rigid. Initial studies of the importance of hydroelasticity for wave loads on an existing deck structure have been performed. For a given design wave, the local structural responses were found to behave quasi-static. Global structural response has not been studied. In the Wagner based method gravity is neglected and a linear spatial distribution of the relative impact velocity along the deck is assumed. The resulting boundary value problem is solved analytically for each time step. A numerical scheme for stepping the wetted deck area in time is presented. The nonlinear boundary element method includes gravity, and the exact impact velocity is considered. The incident wave velocity potential is given a priori, and a boundary value problem for the perturbation velocity potential associated with the impact is defined. The boundary value problem is solved for each time step by applying Green's second identity. The exact boundary conditions are imposed on the exact boundaries. A Kutta condition is introduced as the fluid flow reaches the downstream end of the deck. At present, the BEM is only applicable for fixed platform decks. To validate the theories, experiments have been carried out in a wave flume. The experiments were performed in two-dimensional flow condition with a fixed horizontal deck at different vertical levels above the mean free surface. The vertical force on the deck and the wetting of the deck were the primary parameters measured. Only regular propagating waves were applied. When a wave hits the deck, the

  19. Experimental and theoretical study of steam condensation induced water hammer phenomena

    International Nuclear Information System (INIS)

    Barna, Imre Ferenc; Baranyai, Gabor; Ezsoel, Gyoergy

    2009-01-01

    We investigate steam condensation induced water hammer (waha) phenomena and present experimental and theoretical results. Some of the experiments were performed in the PMK-2 facility, which is a full-pressure thermohydraulic model of the nuclear power plant of VVER-440/312 type and located in the Atomic Energy Research Institute Budapest, Hungary. Other experiments were done in the ROSA facility in Japan. On the theoretical side waha is studied and analyzed with the WAHA3 model based on two-phase flow six first-order partial differential equations that present one dimensional, surface averaged mass, momentum and energy balances. A second order accurate high-resolution shock-capturing numerical scheme was applied with different kind of limiters in the numerical calculations. The applied two-fluid model shows some similarities to Relap5 which is widely used in the nuclear industry to simulate nuclear power plant accidents. Experimentally measured and theoretically calculated waha pressure peaks are in qualitative agreement. (author)

  20. Theoretical and experimental studies on dynamics of double-helical gear system supported by journal bearings

    Directory of Open Access Journals (Sweden)

    Minghu Yin

    2016-05-01

    Full Text Available The dynamic behaviour of a double-helical gear system supported by journal bearings is theoretically and experimentally investigated in this study. A bending–torsional–axial coupling model for dynamic analysis of double-helical gear system is developed. Influence of the time-varying mesh stiffness and damping is considered. Oil film stiffness and damping of the supporting journal bearing are supposed to be time-varying, and the time-varying oil film stiffness and damping are predicted by a back propagation neural network, which is optimized by genetic algorithm. A double-helical gear–rotor–journal bearing system test rig is also established to carry out the experimental investigations, such as the dynamic transmission errors of gear pairs. The comparisons between theoretical and experimental results show that the time-varying oil film dynamic coefficients of journal bearings are an important internal excitation. The theoretical model with time-varying oil film stiffness and damping can predict the gear dynamics more accurate than the model with time-invariant oil film stiffness and damping, and the neural network optimized by genetic algorithm can obtain the time-varying oil film stiffness and damping efficiently and accurately for the dynamic analysis of double-helical gear system.

  1. Experiences of using the Theoretical Domains Framework across diverse clinical environments: a qualitative study.

    Science.gov (United States)

    Phillips, Cameron J; Marshall, Andrea P; Chaves, Nadia J; Jankelowitz, Stacey K; Lin, Ivan B; Loy, Clement T; Rees, Gwyneth; Sakzewski, Leanne; Thomas, Susie; To, The-Phung; Wilkinson, Shelley A; Michie, Susan

    2015-01-01

    The Theoretical Domains Framework (TDF) is an integrative framework developed from a synthesis of psychological theories as a vehicle to help apply theoretical approaches to interventions aimed at behavior change. This study explores experiences of TDF use by professionals from multiple disciplines across diverse clinical settings. Mixed methods were used to examine experiences, attitudes, and perspectives of health professionals in using the TDF in health care implementation projects. Individual interviews were conducted with ten health care professionals from six disciplines who used the TDF in implementation projects. Deductive content and thematic analysis were used. Three main themes and associated subthemes were identified including: 1) reasons for use of the TDF (increased confidence, broader perspective, and theoretical underpinnings); 2) challenges using the TDF (time and resources, operationalization of the TDF) and; 3) future use of the TDF. The TDF provided a useful, flexible framework for a diverse group of health professionals working across different clinical settings for the assessment of barriers and targeting resources to influence behavior change for implementation projects. The development of practical tools and training or support is likely to aid the utility of TDF.

  2. Theoretical study on functionally graded cylindrical magnetoelectric composites using d15 shear-mode response

    Science.gov (United States)

    Shi, Yang; Gao, Yuanwen

    2017-08-01

    In this study, a novel functionally graded cylindrical magnetoelectric (ME) composite based on d15 shear-mode response is analyzed theoretical by using the elastic mechanics model and equivalent circuit model. The composite is mounted around AC current-carrying power lines to scavenge AC magnetic field energy. For different sensing configurations, the generated magnetic fields are calculated, respectively. Then, based on the theoretical models, the dependences of the ME performances, i.e., the ME voltage and power, upon the type of the material gradation, the material constants, and geometrical parameters of the cylindrical ME composite are numerically evaluated. The results show that the ME coupling effect in the functionally graded cylindrical ME composite with special gradation is stronger than that in the homogeneous structure. The ME performance can be improved by geometrical parameters as well. The presented two models can be synthesized under the open-circuit condition, which provide a theoretical basis to understand and improve the ME property of the d15 shear-mode cylindrical ME composites operating at resonant frequency and off-resonance frequency.

  3. The defect chemistry of nitrogen in oxides: A review of experimental and theoretical studies

    International Nuclear Information System (INIS)

    Polfus, Jonathan M.; Norby, Truls; Haugsrud, Reidar

    2013-01-01

    Incorporation of nitrogen into oxides has in recent years received increased attention as a variable for tuning their functional properties. A vast number of reports have been devoted to improving the photocatalytic properties of TiO 2 , p-type charge carrier concentration in ZnO and the ionic transport properties of ZrO 2 by nitrogen doping. In comparison, the fundamentals of the nitrogen related defect chemistry for a wider range of oxides have been less focused upon. In the present contribution, we review experimental and computational investigations of the nitrogen related defect chemistry of insulating and semiconducting oxides. The interaction between nitrogen and protons is important and emphasized. Specifically, the stability of nitrogen defects such as N O / , NH O × and (NH 2 ) O • is evaluated under various conditions and their atomistic and electronic structure is presented. A final discussion is devoted to the role of nitrogen with respect to transport properties and photocatalytic activity of oxides. - Graphical abstract: Experimental and theoretical investigations of the nitrogen related defect chemistry of a range of wide band gap oxides is reviewed. The interaction between nitrogen dopants and protons is emphasized and described through the atomistic and electronic structure as well as defect chemical processes involving NH and NH 2 defects. Consequently, the physical properties of oxides containing such species are discussed with respect to e.g., diffusion and photocatalytic properties. Highlights: ► Experimental and theoretical investigations of the nitrogen and hydrogen related defect chemistry of wide band gap oxides is reviewed. ► The interaction between nitrogen dopants and protons is important and emphasized. ► Diffusion and photocatalytic properties of N-doped oxides are discussed.

  4. Theoretical study of structure of electric field in helical toroidal plasmas

    International Nuclear Information System (INIS)

    Toda, S.; Itoh, K.

    2001-06-01

    A set of transport equations is analyzed, including the bifurcation of the electric field. The structure of the electric field is studied by use of the theoretical model for the anomalous transport diffusivities. The steep gradient of the electric field is obtained at the electric domain. The suppression of the anomalous transport diffusivity is studied in the presence of the strong shear of the electric field. The hard transition with the multiple ambipolar solutions is examined in the structure of the radial electric field. The details of the structure of the electric domain interface are investigated. (author)

  5. Theoretical and Empirical Studies of the Professional Career: Integration Prospects on the Basis P. Bourdieu's Theory

    Directory of Open Access Journals (Sweden)

    P S Sorokin

    2012-03-01

    Full Text Available The article discusses the main current approaches to the interpretation of the term professional career, as well as the established lines of empirical study of the factors of career development. The author points out to the insufficient co-ordination between the efforts of theoretical conceptualization of career-related issues and the empirical studies of this subject. The author analyzes the most promising directions for further career research in terms of Bourdieu's theory of social space. Primarily, the author focuses on elaborating the concepts of career field and career capital related to it.

  6. Status of molten fuel coolant interaction studies and theoretical modelling work at IGCAR

    International Nuclear Information System (INIS)

    Rao, P.B.; Singh, Om Pal; Singh, R.S.

    1994-01-01

    The status of Molten Fuel Coolant Interaction (MFCI) studies is reviewed and some of the important observations made are presented. A new model for MFCI that is developed at IGCAR by considering the various mechanisms in detail is described. The model is validated and compared with the available experimental data and theoretical work at different stages of its development. Several parametric studies that are carried using this model are described. The predictions from this model have been found to be satisfactory, considering the complexity of the MFCI. A need for more comprehensive and MFCI-specific experimental tests is brought out. (author)

  7. Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yuwei; Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn; Li, Xi; Yang, Aijun; Wu, Yi; Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, No. 28 XianNing West Road, Xi’an, Shaanxi Province 710049 (China); Han, Guohui; Lu, Yanhui [Pinggao Group Co. Ltd., Pingdingshan, Henan Province 467001 (China)

    2016-08-15

    formation of IV a, IV b and products of CF{sub 3} + CF-CF{sub 3} in pathway IV. Although IV a is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF{sub 3}, C = CF{sub 2} as well as C-CF{sub 3} species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway V I of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states). This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK.

  8. Study of final states in deep inelastic muon scattering

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to study the different possible final states in deep inelastic muon scattering from hydrogen in connection with the detection of the scattered muon in a forward spectrometer (Experiment NA2).\\\\ \\\\ A vertex detector will be used which extends the hadron detection capabilities into the backward hemisphere of the centre-of-mass system. Particle momenta can be measured down to 200 MeV/c in a vertex magnet, which contains a streamer chamber (SC Particle identification will be done in a series of wide angle Čerenkov counters (C$_{0}$, C$_{1}$) and at low momenta in time-of-flight counter hodoscopes (F1-F4). An 8-plane module of MWPC chambers (PV) will be used in conjunction with the streamer chamber and the drift chambers WV1 and WV2 and WV3. \\\\ \\\\ The vertex magnet is a C magnet with circular pole tips of 2 m diameter and 1 m gap width. The central magnetic field will be 1.5 T. The streamer chamber (2m x 1.2m x 0.72m) will contain a 1 m liquid H$_{2}$ target.\\\\ \\\\ As a natural extens...

  9. Actinide partitioning-transmutation program final report. III. Transmutation studies

    International Nuclear Information System (INIS)

    Wachter, J.W.; Croff, A.G.

    1980-07-01

    Transmutation of the long-lived nuclides contained in fuel cycle wastes has been suggested as a means of reducing the long-term toxicity of the wastes. A comprehensive program to evaluate the feasibility and incentives for recovering the actinides from wastes (partitioning) and transmuting them to short-lived or stable nuclides has been in progress for 3 years under the direction of Oak Ridge National Laboratory (ORNL). This report constitutes the final assessment of transmutation in support of this program. Included are (1) a summary of recent transmutation literature, (2) a generic evaluation of actinide transmutation in thermal, fast, and other transmutation devices, (3) a preliminary evaluation of 99 Tc and 129 I transmutation, and (4) a characterization of a pressurized-water-reactor fuel cycle with and without provisions for actinide recovery and transmutation for use in other parts of the ORNL program. The principal conclusion of the report is that actinide transmutation is feasible in both thermal and fast reactors, subject to demonstrating satisfactory fuel performance, with relatively little impact on the reactor. It would also appear that additional transmutation studies are unwarranted until a firm decision to proceed with actinide transmutation has been made by the responsible authorities

  10. Finalization of the feasibility study for Rocky Mountain arsenal

    International Nuclear Information System (INIS)

    Parks, D.M.; Amdurer, M.

    1994-01-01

    The environmental remediation program at the Army's premier cleanup site, Rocky Mountain Arsenal, is fast approaching the climax of the study phase and will be moving into the cleanup phase. Selecting the cleanup approach for this extremely complex site involves addressing a number of precedent-setting issues. The Remedial Investigation (RI) for this 27-sq. mile former Army chemical munitions and commercial pesticide manufacturing facility, completed in January 1992, included the collection of over 50,000 samples from soil, surface water, groundwater, structures, air and plants and animals. Samples were analyzed for over 60 specific chemical analytes and screened for hundreds of others. The RI found a number of contaminated groundwater plumes, hundreds of contaminated structures, high concentrations of contaminants in soils in former disposal basins and manufacturing areas and buried munitions. Some of the major contaminants targeted for remediation include benzene, chloroform, tetrachloroethylene, dibromochloropropane, diisopropylmethyl phosphonate, aldrin, adieldrin, isodrin, chlordane, lead, arsenic and mercury. The Feasibility Study (FS) has reviewed potential remediation alternatives. The first phase of the FS, the Development and Screening of Alternatives (DSA) presented a range of alternatives. An equally complex and parallel study, the Integrated Endangerment Assessment, is in final stages. The goal of the second phase of the FS, the Detailed Analysis of Alternatives (DAA), is to analyze the soils, water and structures alternatives retained in the DSA in greater technical detail. The Army's draft version of the DAA, released in the Fall of 1993, has proposed a wide range of alternatives to remediate 27 different contamination groups and is included in the presentation

  11. Theoretical chemistry

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Work in theoretical chemistry was organized under the following topics: scattering theory and dynamics (elastic scattering of the rare gas hydrides, inelastic scattering in Li + H 2 , statistical theory for bimolecular collisions, model study of dissociative scattering, comparative study of elastic scattering computational methods), studies of atmospheric diatomic and triatomic species, structure and spectra of diatomic molecules, the evaluation of van der Waals forces, potential energy surfaces and structure and dynamics, calculation of molecular polarizabilities, and development of theoretical techniques and computing systems. Spectroscopic parameters are tabulated for NO 2 , N 2 O, H 2 O + , VH, and NH. Self-consistent-field wave functions were computed for He 2 in two-center and three-center bases. Rare gas hydride intermolecular potentials are shown. (9 figures, 14 tables) (U.S.)

  12. Solvation of fluoroform and fluoroform-dimethylether dimer in liquid krypton: A theoretical cryospectroscopic study

    Science.gov (United States)

    Kohls, Emilija; Mishev, Anastas; Pejov, Ljupčo

    2013-08-01

    A hybrid, sequential statistical physics-quantum mechanical electronic-quantum mechanical nuclei approach has been applied to study the C-H stretching frequencies of bare fluoroform dissolved in liquid krypton under cryogenic conditions (at ˜130 K), as well as upon blue shifting hydrogen bonding interactions with dimethylether in the same solvent. The structure of the liquid at 130 K was generated by Monte Carlo simulations of cryogenic Kr solutions containing either fluoroform or fluoroform and dimethylether molecules. Statistically uncorrelated configurations were appropriately chosen from the equilibrated MC runs and supermolecular clusters containing solute and solvent molecules (either standalone or embedded in the "bulk" part of the solvent treated as a polarizable continuum) were subjected to quantum mechanical electronic (QMel) and subsequent quantum mechanical nuclei (QMnuc) calculations. QMel calculations were implemented to generate the in-liquid 1D intramolecular C-H stretching vibrational potential of the fluoroform moiety and subsequently in the QMnuc phase the corresponding anharmonic C-H stretching frequency was computed by diagonalization techniques. Finally, the constructed vibrational density of states histograms were compared to the experimental Raman bands. The calculated anharmonic vibrational frequency shifts of the fluoroform C-H stretching mode upon interaction with dimethylether in liquid Kr are in very good agreement with the experimental data (20.3 at MP2 level vs. 16.6 cm-1 experimentally). Most of this relatively large frequency blue shift is governed by configurations characterized by a direct C-H⋯O contact between monomers. The second population detected during MC simulations, characterized by reversed orientation of the monomers, has a minor contribution to the spectral appearance. The experimentally observed trend in the corresponding bandwidths is also correctly reproduced by our theoretical approach. Solvation of the

  13. Thermodynamic analysis and theoretical study of a continuous operation solar-powered adsorption refrigeration system

    International Nuclear Information System (INIS)

    Hassan, H.Z.; Mohamad, A.A.

    2013-01-01

    Due to the intermittent nature of the solar radiation, the day-long continuous production of cold is a challenge for solar-driven adsorption cooling systems. In the present study, a developed solar-powered adsorption cooling system is introduced. The proposed system is able to produce cold continuously along the 24-h of the day. The theoretical thermodynamic operating cycle of the system is based on adsorption at constant temperature. Both the cooling system operating procedure as well as the theoretical thermodynamic cycle are described and explained. Moreover, a steady state differential thermodynamic analysis is performed for all components and processes of the introduced system. The analysis is based on the energy conservation principle and the equilibrium dynamics of the adsorption and desorption processes. The Dubinin–Astakhov adsorption equilibrium equation is used in this analysis. Furthermore, the thermodynamic properties of the refrigerant are calculated from its equation of state. The case studied represents a water chiller which uses activated carbon–methanol as the working pair. The chiller is found to produce a daily mass of 2.63 kg cold water at 0 °C from water at 25 °C per kg of adsorbent. Moreover, the proposed system attains a cooling coefficient of performance of 0.66. - Highlights: • A new continuous operation solar-driven adsorption refrigeration system is introduced. • The theoretical thermodynamic cycle is presented and explained. • A complete thermodynamic analysis is performed for all components and processes of the system. • Activated carbon–methanol is used as the working pair in the case study

  14. Single-phase and two phase bubbly flow in a T connection: theoretical and experimental study

    International Nuclear Information System (INIS)

    Hervieu, Eric

    1988-01-01

    The objective of this research thesis is to highlight the driving factors of the separation of phases of a bubbly flow in a T junction, and to develop a prediction model. In a first part, the author reports the rigorous formulation of equations averaged on the T volume. He shows that it's not possible to solve globally the problem with these equations. Then, he reports a bibliographical study on the modelling of a bubbly flow, and, based upon this study, highlights intrinsic characteristics of the flow, and explains its dynamic mechanisms. He reports the development of the theoretical model, and describes the experimental installation used to validate it. In the third part, he reports the study of the liquid-gas interaction, and presents the adopted approach: study of the behaviour of an isolated bubble within a single-phase flow. Experimentation is used to check theoretical predictions. Results are used to compute phase separation. The obtained results are again compared with experimental results to validate the global relevance of the model [fr

  15. Epidemiology of a thermonuclear bomb-burst over Nashville, Tennessee: a theoretic study

    International Nuclear Information System (INIS)

    Quinn, R.W.

    1983-01-01

    A thermonuclear bomb explosion over any city in the world would have a devastating effect on the population and environment. For those who survive, with or without injuries, life would become primitive with little or no uncontaminated food or water, and with inadequate housing, fuel, and medical care, resulting in a breakdown of family and interpersonal relationships. This theoretic study of the potential outcome of a thermonuclear bomb-burst over Nashville, Tennessee, discusses epidemiologically the wide range of medical and psychologic effects from the direct trauma of blast and fire, widespread epidemics of otherwise controlled disease, long-term chronic illness, genetic damage, and catastrophic environmental havoc

  16. Experimental study and theoretical modeling of bidimensional beam fanning: application to DPCM

    Science.gov (United States)

    Mailhan, C.; Goetz, M.; Fressengeas, N.; Kugel, G.

    2001-10-01

    Features like efficiency and stability of the double phase conjugate mirror (DPCM) in BaTiO 3 obviously depend on the beam fanning (BF) experienced by each incident beam. We propose here a new approach to DPCM optimization which consists in studying the BF phenomenon for each interacting beam. This allows one to choose the best angular configuration of the incident beams in DPCM. The investigation is experimental, by recording the fanning patterns, and also theoretical, by interpreting numerically these patterns on the basis of the coupling gain maximization in the two-wave mixing theory. We focus on the influence of the incident beam width and incidence angle.

  17. Theoretical and experimental study of electroporation of red blood cells using MEMS technology

    KAUST Repository

    Deng, Peigang

    2010-01-01

    A theoretical and experimental study of electroporation (EP) of red blood cells (RBCs) was presented in this paper. With additional strain energy, an energy-based model of an electropore induced on a RBC\\'s membrane at different electric fields was proposed to predict the critical EP electric field strength. In addition, EP experiments with red blood cells at single-cell level was carried out on a micro EP chip. The measured critical EP electric field strengths are in agreement with the numerical predictions. ©2010 IEEE.

  18. Theoretical and experimental study of microstrip-to-slot line uniplanar transition

    Science.gov (United States)

    Yook, Jong-Gwan; Dib, Nihad I.; Katehi, Linda P. B.; Simons, Rainee N.; Taub, Susan R.

    1994-05-01

    Recent advances in MMCI technology make it possible to construct transitions from CPW-to-microstrip with via hole, microstrip-to-slot line and microshield line-to-CPW all of which have potential applications in the feed network of antennas. In this study we investigate the characteristics of the microstrip-to-slot line uniplanar transition using the finite element methods (FEM) and finite difference time domain (FDTD) techniques, and compared the theoretical results with the measurements. In both cases, the results agree with the measurements within a few percent.

  19. Theoretical study of catalytic hydrogenation of oxirane and its methyl derivative

    Directory of Open Access Journals (Sweden)

    U.A. Kuevi

    2012-12-01

    Full Text Available Oxirane (C2H4O is an unsaturated heterocyclic compound and methyloxirane (C3H6O is its methyl derivative. Theoretical studies on catalytic hydrogenation of both compounds, in presence of aluminium chloride (AlCl3 catalyst, are carried out. The products of reactions are ethanol and propan-1-ol from oxirane and methyloxirane, respectively. According to the variations of chemical parameters throughout the processes, the mechanisms of both reactions have been proposed.DOI: http://dx.doi.org/10.4314/bcse.v26i3.13

  20. Experimental study and theoretical simulation of the cross hardening effect in shape memory alloys

    Science.gov (United States)

    Movchan, A. A.; Sil'chenko, A. L.; Kazarina, S. A.

    2017-10-01

    The shapes and the relative position of martensitic inelasticity and forward transformation diagrams are experimentally studied. The strain dependences of the stress in loading under martensitic inelasticity conditions after an experiment on the accumulation of the forward transformation-induced strain at a constant or variable stress are investigated on titanium nickelide samples. It is found that the hardening of the martensite part of the representative volume of a shape memory alloy (titanium nickelide) after forward transformation under a nonmonotonically changing stress can be nonuniform. The cross hardening phenomenon is theoretically described in terms of the model of nonlinear deformation of a shape memory alloy during phase and structural transformations.

  1. Theoretical Studying and Numerical Simulation of an Electrical Discharge in Vaccum

    Science.gov (United States)

    Severin, Francois; de La Bourdonnaye, Armel; Marque, Jean-Pierre

    1998-11-01

    Dielectric discharges are a well known source of perturbations on Spacecraft, see for example some papers of the 6th Conference. Many questions occur about their mecanisms but few detailed physical insights are proposed and still less are the subject of a numerical simulation. In this paper, we focused on a discharge model proposed by Jean-Pierre Marque [1, 2]. The theoretical and numerical study of this discharge is made in [3]. This paper is devoted to the physical aspects of the propagation modelling.

  2. An experimental and theoretical study of a CO{sub 2} ejector

    Energy Technology Data Exchange (ETDEWEB)

    Guangming, Chen; Xiaoxiao, Xu; Shuang, Liu; Lixia, Liang; Liming, Tang [Institute of Refrigeration and Cryogenics, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China)

    2010-08-15

    In this paper we represent the performance of an ejector used in the CO{sub 2} heat pump water heater system by means of experimental and theoretical studies. This work accounts for the effects of primary flow pressure, entrained flow pressure and back pressure on the entrainment ratio in off-design conditions. The performance of the ejector is experimentally investigated in a CO{sub 2}-ejector test rig. Using ejector characteristic-curve equations, we provide predictions in good agreement with the experimental data. Furthermore, the model predictions will be utilized as a design tool for optimizing the performance of next generation ejector. (author)

  3. Self-propelled Leidenfrost drops on a thermal gradient: A theoretical study

    Science.gov (United States)

    Sobac, B.; Rednikov, A.; Dorbolo, S.; Colinet, P.

    2017-08-01

    We theoretically investigate the behavior of Leidenfrost drops on a flat substrate submitted to a horizontal thermal gradient and highlight that they are able to self-propel in a preferential direction. Namely, they are found to travel towards the colder parts of the substrate, as if they were trying to maximize their lifetime. In particular, a centimetric water drop can reach velocities of the order of cm/s for thermal gradients of the order of a few K/mm. In general, the presented model, based upon the lubrication approximation in the vapor cushion as in the work of Sobac et al. ["Leidenfrost effect: Accurate drop shape modeling and new scaling laws," Phys. Rev. E 90, 053011 (2014)] and here formulated for simplicity for a 2D drop, enables predicting the values of these velocities as a function of the thermal gradient, drop size, superheat, and fluid properties. Surprisingly, the variability of vapor properties with temperature turns out to be instrumental for the drop to move, even if the vapor film profile is always asymmetric anyway. Finally, this asymmetry being typically weak, its effect also proved to be well captured by linearization around the corresponding symmetric Leidenfrost state.

  4. Theoretical study of elastic, mechanical and thermodynamic properties of MgRh intermetallic compound

    Directory of Open Access Journals (Sweden)

    S. Boucetta

    2014-03-01

    Full Text Available In the last years, Magnesium alloys are known to be of great technological importance and high scientific interest. In this work, density functional theory plane-wave pseudo potential method, with local density approximation (LDA and generalized gradient approximation (GGA are used to perform first-principles quantum mechanics calculations in order to investigate the structural, elastic and mechanical properties of the intermetallic compound MgRh with a CsCl-type structure. Comparison of the calculated equilibrium lattice constant and experimental data shows good agreement. The elastic constants were determined from a linear fit of the calculated stress–strain function according to Hooke's law. From the elastic constants, the bulk modulus B, shear modulus G, Young's modulus E, Poisson's ratio σ, anisotropy factor A and the ratio B/G for MgRh compound are obtained. The sound velocities and Debye temperature are also predicted from elastic constants. Finally, the linear response method has been used to calculate the thermodynamic properties. The temperature dependence of the enthalpy H, free energy F, entropy S, and heat capacity at constant volume Cv of MgRh crystal in a quasi-harmonic approximation have been obtained from phonon density of states and discussed for the first report. This is the first quantitative theoretical prediction of these properties.

  5. Electronic states of o-nitrobenzaldehyde: a combined experimental and theoretical study.

    Science.gov (United States)

    Leyva, Verónica; Corral, Inés; Schmierer, Thomas; Heinz, Björn; Feixas, Ferran; Migani, Annapaola; Blancafort, Lluís; Gilch, Peter; González, Leticia

    2008-06-12

    The experimental UV/vis absorption spectrum of ortho-nitrobenzaldehyde (o-NBA) has been assigned by means of MS-CASPT2/CASSCF, TD-DFT, and RI-CC2 theoretical computations. Additional information on the nature of the absorbing bands was obtained by comparing the o-NBA spectrum with that of related compounds, as, e.g., nitrobenzene and benzaldehyde. For wavelengths larger than approximately 280 nm, the absorption spectrum of o-NBA is dominated by a series of weak n pi* absorptions from the NO2 and CHO groups. These weak transitions are followed in energy by a more intense band, peaking at 250 nm and arising from charge transfer pi pi* excitations involving mainly benzene and nitro orbitals. Finally, the most intense band centered at 220 nm has its origin in the overlap of two different absorptions: the first one localized in the NO2 substituent and the second one arising from a charge transfer excitation involving the NO2 and the CHO fragments, respectively.

  6. Theoretical and Experimental Studies of Epidermal Heat Flux Sensors for Measurements of Core Body Temperature.

    Science.gov (United States)

    Zhang, Yihui; Webb, Richard Chad; Luo, Hongying; Xue, Yeguang; Kurniawan, Jonas; Cho, Nam Heon; Krishnan, Siddharth; Li, Yuhang; Huang, Yonggang; Rogers, John A

    2016-01-07

    Long-term, continuous measurement of core body temperature is of high interest, due to the widespread use of this parameter as a key biomedical signal for clinical judgment and patient management. Traditional approaches rely on devices or instruments in rigid and planar forms, not readily amenable to intimate or conformable integration with soft, curvilinear, time-dynamic, surfaces of the skin. Here, materials and mechanics designs for differential temperature sensors are presented which can attach softly and reversibly onto the skin surface, and also sustain high levels of deformation (e.g., bending, twisting, and stretching). A theoretical approach, together with a modeling algorithm, yields core body temperature from multiple differential measurements from temperature sensors separated by different effective distances from the skin. The sensitivity, accuracy, and response time are analyzed by finite element analyses (FEA) to provide guidelines for relationships between sensor design and performance. Four sets of experiments on multiple devices with different dimensions and under different convection conditions illustrate the key features of the technology and the analysis approach. Finally, results indicate that thermally insulating materials with cellular structures offer advantages in reducing the response time and increasing the accuracy, while improving the mechanics and breathability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Theoretical and Experimental Studies of Epidermal Heat Flux Sensors for Measurements of Core Body Temperature

    Science.gov (United States)

    Zhang, Yihui; Webb, Richard Chad; Luo, Hongying; Xue, Yeguang; Kurniawan, Jonas; Cho, Nam Heon; Krishnan, Siddharth; Li, Yuhang; Huang, Yonggang

    2016-01-01

    Long-term, continuous measurement of core body temperature is of high interest, due to the widespread use of this parameter as a key biomedical signal for clinical judgment and patient management. Traditional approaches rely on devices or instruments in rigid and planar forms, not readily amenable to intimate or conformable integration with soft, curvilinear, time-dynamic, surfaces of the skin. Here, materials and mechanics designs for differential temperature sensors are presented which can attach softly and reversibly onto the skin surface, and also sustain high levels of deformation (e.g., bending, twisting, and stretching). A theoretical approach, together with a modeling algorithm, yields core body temperature from multiple differential measurements from temperature sensors separated by different effective distances from the skin. The sensitivity, accuracy, and response time are analyzed by finite element analyses (FEA) to provide guidelines for relationships between sensor design and performance. Four sets of experiments on multiple devices with different dimensions and under different convection conditions illustrate the key features of the technology and the analysis approach. Finally, results indicate that thermally insulating materials with cellular structures offer advantages in reducing the response time and increasing the accuracy, while improving the mechanics and breathability. PMID:25953120

  8. Theoretical Study of the AC Conduction in β-In2S3

    Science.gov (United States)

    Abassi, H.; Bouguila, N.; Timoumi, A.

    2018-02-01

    β-In2S3 is of great interest in photovoltaic applications and presents a certain number of vacant sites allowing the displacement of indium atoms by hopping from one site to another. Recently, it has been shown that it exhibits ionic behavior. Experimental works have been carried out in order to study the alternating current (AC) conductivity in β-In2S3, showing the validity of the hopping model (correlated barrier hopping; CBH) in the frequency range not exceeding ω = 104 Hz. For ω > 104 Hz, the transport mechanism was dominated by small polaron tunneling (SPT). The theoretical model developed in this work in order to study the AC conductivity is based on the hopping model adapted to the case of β-In2S3 by considering the jump of indium ions from one site to another. We report the frequency and temperature dependence on β-In2S3 AC conductivity. An examination of the experimental results shows a qualitative compatibility of our model. Indeed, our theoretical simulations are in agreement with the experimental data in the same frequency range where the CBH model was dominant. A quantitative discrepancy between theory and experiment has been observed beyond this frequency range where the SPT has been dominant. This discrepancy increases by raising the temperature. A FORTRAN program based on the Lenvenberg-Marquardt method was established to determine the fitting curve of the theoretical model to the experimental. This program allowed us to deduce the vibration frequencies about the equilibrium of indium atoms in the case of β-In2S3 which are parameters of fundamental importance in solid-state physics. The vibration modes obtained from the numerical simulation are in agreement with the orders of magnitude found in the literature.

  9. Exploratory experimental and theoretical studies of cyclone gasification of wood powder

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, Christian

    1999-11-01

    This thesis describes an exploratory experimental and theoretical study of gasification of wood powder in a cyclone gasifier. The generated gas could be used to operate a gas turbine in a combined cycle power plant. The objective has been to develop the understanding of cyclone gasification by experimental studies of the performance of a cyclone designed in principle as a separation cyclone and by comparisons between the experimental results and theoretical predictions. The experiments were carried out with commercial Swedish wood powder fuels, injected with air or steam/air mixture through two diametrically opposite tangential inlets and gasified at atmospheric pressure in cyclones of two different configurations with a volume of about 0.034 m{sup 3}. The studies show that stable gasification of this fuel can be obtained for a specific fuel feeding rate of about 5 MW/m{sup 3} cyclone volume for equivalence ratios above 0.15 and that the equivalence ratio had to be kept below about 0.4 in order to avoid material temperatures above 950 deg C. A cyclone with a short outlet pipe, designed as a conventional separation cyclone was found to give lower char conversion than a modified cyclone with a long outlet pipe. The heating value of the gas was found to be approximately 4.5 MJ/kg. The dust load in the product gas was measured to between 1000 and 2500 mg/Nm{sup 3}. It was possible to separate at least 40-60% of the potassium and 60-90% of the sodium supplied with the wood. The alkali that left the cyclone with the product gas appear to be in solid or melted phase in the unseparated char particles and consequently not vaporised during gasification. As the K and Na were assumed to remain within the particles during gasification, it was concluded that to reduce the amount of alkali metals in the product gas it would be necessary to improve the particle separation efficiency. The results of the theoretical modelling, using the existing models in the commercial software CFX

  10. Theoretical and experimental studies of heavy liquid metal thermal hydraulics. Proceedings of a technical meeting

    International Nuclear Information System (INIS)

    2006-10-01

    Through the Nuclear Energy Department's Technical Working Group on Fast Reactors (TWG-FR), the IAEA provides a forum for exchange of information on national programmes, collaborative assessments, knowledge preservation, and cooperative research in areas agreed by the Member States with fast reactor and partitioning and transmutation development programmes (e.g. accelerator driven systems (ADS)). Trends in advanced fast reactor and ADS designs and technology development are periodically summarized in status reports, symposia, and seminar proceedings prepared by the IAEA to provide all interested IAEA Member States with balanced and objective information. The use of heavy liquid metals (HLM) is rapidly diffusing in different research and industrial fields. The detailed knowledge of the basic thermal hydraulics phenomena associated with their use is a necessary step for the development of the numerical codes to be used in the engineering design of HLM components. This is particularly true in the case of lead or lead-bismuth eutectic alloy cooled fast reactors, high power particle beam targets and in the case of the cooling of accelerator driven sub-critical cores where the use of computational fluid dynamic (CFD) design codes is mandatory. Periodic information exchange within the frame of the TWG-FR has lead to the conclusion that the experience in HLM thermal fluid dynamics with regard to both the theoretical/numerical and experimental fields was limited and somehow dispersed. This is the case, e.g. when considering turbulent exchange phenomena, free-surface problems, and two-phase flows. Consequently, Member States representatives participating in the 35th Annual Meeting of the TWG-FR (Karlsruhe, Germany, 22-26 April 2002) recommended holding a technical meeting (TM) on Theoretical and Experimental Studies of Heavy Liquid Metal Thermal Hydraulics. Following this recommendation, the IAEA has convened the Technical Meeting on Theoretical and Experimental Studies of

  11. Theoretical foundations of international migration process studies: analysis of key migration theories development

    Directory of Open Access Journals (Sweden)

    Shymanska K.V.

    2017-03-01

    Full Text Available The need for transformation of Ukraine's migration policy based on globalized world development trends and in response to the challenges of European integration transformations causes the need of researching the theoretical and methodological basis of migration studies, and the regulations of existing theories of international migration. The bibliometric analysis of scientific publications on international migration in cites indexes found that the recent researches on these problems acquire interdisciplinary character. It necessitates the transformation of migration study approaches basing on economic, social, institutional theories and concepts synthesis. The article is devoted to the study of theoretical regulations of existing international migration theories in the context of the evolution of scientists’ views on this phenomenon. The author found that the existing theories of international migration should be divided into three categories (microeconomic, macroeconomic, globalizational that contributes to their understanding in the context of implementation possibilities in migrational public administration practice. It allows to determine the theories which should be used for Ukrainian state migration policy constructing and eliminating or reducing the external migration negative effects.

  12. The social embeddedness of media use - Action theoretical contributions to the study of TV use in everyday life

    NARCIS (Netherlands)

    Westerik, H.

    2009-01-01

    Scholars in the field of communication research have extensively studied television viewing in general and watching television news in particular. The book looks at the subject from an integrative theoretical perspective. Based on Schutzean sociology and action theoretical approaches to media use,

  13. Pulsed Neutron Scattering Studies of Strongly Fluctuating solids, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Collin Broholm

    2006-06-22

    The conventional description of a solid is based on a static atomic structure with small amplitude so-called harmonic fluctuations about it. This is a final technical report for a project that has explored materials where fluctuations are sufficiently strong to severely challenge this approach and lead to unexpected and potentially useful materials properties. Fluctuations are enhanced when a large number of configurations share the same energy. We used pulsed spallation source neutron scattering to obtain detailed microscopic information about structure and fluctuations in such materials. The results enhance our understanding of strongly fluctuating solids and their potential for technical applications. Because new materials require new experimental techniques, the project has also developed new techniques for probing strongly fluctuating solids. Examples of material that were studied are ZrW2O8 with large amplitude molecular motion that leads to negative thermal expansion, NiGa2S4 where competing interactions lead to an anomalous short range ordered magnet, Pr1- xBixRu2O7 where a partially filled electron shell (Pr) in a weakly disordered environment produces anomalous metallic properties, and TbMnO3 where competing interactions lead to a magneto-electric phase. The experiments on TbMnO3 exemplify the relationship between research funded by this project and future applications. Magneto-electric materials may produce a magnetic field when an electric field is applied or vise versa. Our experiments have clarified the reason why electric and magnetic polarization is coupled in TbMnO3. While this knowledge does not render TbMnO3 useful for applications it will focus the search for a practical room temperature magneto-electric for applications.

  14. Study of the hydroxyl radical: Experimental advances in microwave spectroscopy, theoretical model and astrophysical consequences

    International Nuclear Information System (INIS)

    Destombes, Jean-Luc

    1978-01-01

    This research thesis mainly addresses the experimental and theoretical study of the hydroxyl radical, and the consequences of the obtained results in astrophysics which are studied with a model of pumping by the far infrared. After a recall of notions related to microwave spectroscopy and to molecular radio-astronomy, the author more particularly discusses different aspects of microwave spectroscopy in the interstellar environment and in laboratory. He also reviews different types of spectrometers for unsteady molecules. In the second part, he addresses issues related to the hydroxyl radical (OH): presentation of spectrometers, study of the reaction environment, study of the radical microwave spectrum, identification of transitions by frequency measurements. In the last parts, the author addresses some aspects of interstellar OH masers, and reports the application of some results to simple models of pumping by the far infra red

  15. Electronic and optical response of functionalized Ru(II) complexes: joint theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kilina, Svetlana [Los Alamos National Laboratory; Tretiak, Sergei [Los Alamos National Laboratory; Sykora, Milan [Los Alamos National Laboratory; Albert, Victor [UNIV OF FLORIDA; Badaeva, Ekaterina [UNIV OF WASHINGTON; Koposov, Alexey [UNIV OF WASHINGTON

    2008-01-01

    New photovoltaic and photocatalysis applications have been recently proposed based on the hybrid Ru(II)-bipyridine-complex/semiconductor quantum dot systems. In order to attach the Ru(II) complex to the surface of a semiconductor, a linking bridge -- a carboxyl group -- needs to be added to one or two of the 2,2'-bipyridine (bpy) ligands. Such changes in the ligand structure affect electronic and optical properties and, consequently, the charge transfer reactivity of Ru(II)-systems. In this study, we analyze the effects brought by functionalization of bipyridine ligands with the methyl, carboxyl, and carboxilate groups on the electronic structure and optical response of the [Ru(bpy){sub 3}]{sup 2+} complex. First principle calculations based on density functional theory (DFT) and time dependent DFT (TDDFT) are used to simulate the ground and excited-state properties, respectively, of functionalized Ru-complexes in the gas phase and acetonitrile solution. In addition, an effective Frenkel exciton model is used to explain the optical activity and splitting patterns of the low-energy excited states in all molecules. All theoretical results nicely complement and allow for detailed interpretation of experimental absorption spectra of Ru-complexes that have been done in parallel with our theoretical investigations. We found that the carboxyl group breaks the degeneracy of two low-energy optically bright excited states and red-shifts the absorption spectrum, while leaves ionization and affinity energies of complexes almost unchanged. Experimental studies show that deprotonation of the carboxyl group in the Ru-complexes results in a slight blue shift and decrease of oscillator strengths of the low energy absorption peaks. Comparison of experimental and theoretical linear response spectra of deprotonated complexes demonstrate strong agreement if the theoretical calculations are performed with the addition of a dielectric continuum model. A polar solvent is found to

  16. Threshold collision-induced dissociation and theoretical study of protonated azobenzene

    Science.gov (United States)

    Rezaee, Mohammadreza; McNary, Christopher P.; Armentrout, P. B.

    2017-10-01

    Protonated azobenzene (AB), H+(C6H5N2C6H5), has been studied using threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. Product channels observed are C6H5N2+ + C6H6 and C6H5+ + N2 + C6H6. The experimental kinetic energy-dependent cross sections were analyzed using a statistical model that accounts for internal and kinetic energy distributions of the reactants, multiple collisions, and kinetic shifts. From this analysis, the activation energy barrier height of 2.02 ± 0.11 eV for benzene loss is measured. To identify the transition states (TSs) and intermediates (IMs) for these dissociations, relaxed potential energy surface (PES) scans were performed at the B3LYP/aug-cc-pVTZ level of theory. The PES indicates that there is a substantial activation energy along the dissociation reaction coordinate that is the rate-limiting step for benzene loss and at some levels of theory, for subsequent N2 loss as well. Relative energies of the reactant, TSs, IMs, and products were calculated at B3LYP, wB97XD, M06, PBEPBE, and MP2(full) levels of theory using both 6-311++G(2d,2p) and aug-cc-pVTZ basis sets. Comparison of the experimental results with theoretical values from various computational methods indicates how well these theoretical methods can predict thermochemical properties. In addition to these density functional theory and MP2 methods, several high accuracy multi-level calculations such as CBS-QB3, G3, G3MP2, G3B3MP2, G4, and G4MP2 were performed to determine the thermochemical properties of AB including the proton affinity and gas-phase basicity, and to compare the performance of different theoretical methods.

  17. Theoretical study of the incompressible Navier-Stokes equations by the least-squares method

    Science.gov (United States)

    Jiang, Bo-Nan; Loh, Ching Y.; Povinelli, Louis A.

    1994-01-01

    Usually the theoretical analysis of the Navier-Stokes equations is conducted via the Galerkin method which leads to difficult saddle-point problems. This paper demonstrates that the least-squares method is a useful alternative tool for the theoretical study of partial differential equations since it leads to minimization problems which can often be treated by an elementary technique. The principal part of the Navier-Stokes equations in the first-order velocity-pressure-vorticity formulation consists of two div-curl systems, so the three-dimensional div-curl system is thoroughly studied at first. By introducing a dummy variable and by using the least-squares method, this paper shows that the div-curl system is properly determined and elliptic, and has a unique solution. The same technique then is employed to prove that the Stokes equations are properly determined and elliptic, and that four boundary conditions on a fixed boundary are required for three-dimensional problems. This paper also shows that under four combinations of non-standard boundary conditions the solution of the Stokes equations is unique. This paper emphasizes the application of the least-squares method and the div-curl method to derive a high-order version of differential equations and additional boundary conditions. In this paper, an elementary method (integration by parts) is used to prove Friedrichs' inequalities related to the div and curl operators which play an essential role in the analysis.

  18. A theoretical and numerical study on the mechanics of vibro-acoustic modulation.

    Science.gov (United States)

    Singh, Ashish Kumar; Chen, Boyang; Tan, Vincent B C; Tay, Tong Earn; Lee, Heow Pueh

    2017-04-01

    Vibro-acoustic modulation (VAM) is a form of a non-destructive testing technique used in nonlinear acoustic methods for the detection of defects. It comprises of exciting the structure with a dual frequency sinusoidal signal and studying the interaction of this wave with the underlying defect. In this work a theoretical study on the mechanics of VAM is presented for a generic material body. The roles of different types of defect on the response of the material are analyzed. The theoretical analysis shows the origins of the nonlinear frequencies in the form of higher harmonics and sidebands commonly observed in the output response of VAM excitation. In addition, the analysis provides insights on the relationships between the magnitudes of the nonlinear responses and those of the input vibrations, and on the physical origins of the nonlinear responses. For a physical visualization of the nonlinear vibrations associated with the theory a finite element analysis of VAM is also performed. The model looks into the plausibility of using VAM for the mapping of damage in physical structures. The model is also used to investigate the effects of the defect size and defect depth on the nonlinear mechanism of VAM.

  19. Theoretical study of the binding nature of glassy carbon with nickel(II) phthalocyanine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cortez, Luis [Laboratorio de Quimica Teorica, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile); Berrios, Cristhian [Laboratorio de Electrocatalisis, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile); Yanez, Mauricio [Laboratorio de Recursos Renovables, Centro de Biotecnologia, Universidad de Concepcion, Casilla-160 C, Concepcion (Chile); Cardenas-Jiron, Gloria I., E-mail: gloria.cardenas@usach.cl [Laboratorio de Quimica Teorica, Facultad de Quimica y Biologia, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Santiago (Chile)

    2009-11-26

    A theoretical study at the semiempirical RHF/PM3(tm) level (tm: transition metal) of the binding nature between a glassy carbon (GC) cluster and a nickel(II) complex (nickel(II) phthalocyanine NiPc, nickel(II) tetrasulphophthalocyanine NiTSPc) was performed. Three types of interactions for GC...NiPc (NiTSPc) were studied: (a) through an oxo (O) bridge, (b) through an hydroxo (OH) bridge, and (c) non-bridge. One layer (NiPc, NiTSPc) and two layers (NiPc...NiPc) of complex were considered. The binding energy calculated showed that in both cases NiPc and NiTSPc, the oxo structures are more stable than the hydroxo ones, and than the non-bridge systems. Charge analysis (NAO) predicted that GC gained more electrons in an oxo structure than in the analogues hydroxo. The theoretical results showed an agreement with the experimental data available, an oxo binding between GC and a nickel complex (NiPc, NiTSPc) in aqueous alkaline solutions is formed.

  20. A study of brain networks associated with swallowing using graph-theoretical approaches.

    Directory of Open Access Journals (Sweden)

    Bo Luan

    Full Text Available Functional connectivity between brain regions during swallowing tasks is still not well understood. Understanding these complex interactions is of great interest from both a scientific and a clinical perspective. In this study, functional magnetic resonance imaging (fMRI was utilized to study brain functional networks during voluntary saliva swallowing in twenty-two adult healthy subjects (all females, [Formula: see text] years of age. To construct these functional connections, we computed mean partial correlation matrices over ninety brain regions for each participant. Two regions were determined to be functionally connected if their correlation was above a certain threshold. These correlation matrices were then analyzed using graph-theoretical approaches. In particular, we considered several network measures for the whole brain and for swallowing-related brain regions. The results have shown that significant pairwise functional connections were, mostly, either local and intra-hemispheric or symmetrically inter-hemispheric. Furthermore, we showed that all human brain functional network, although varying in some degree, had typical small-world properties as compared to regular networks and random networks. These properties allow information transfer within the network at a relatively high efficiency. Swallowing-related brain regions also had higher values for some of the network measures in comparison to when these measures were calculated for the whole brain. The current results warrant further investigation of graph-theoretical approaches as a potential tool for understanding the neural basis of dysphagia.

  1. Theoretical analysis and experimental study on the PV-IESAHP system

    Science.gov (United States)

    Wu, Xingying

    2017-05-01

    Solar photovoltaic/thermal integration (PV/T) and heat pump are very important techniques for energy conservation and carbon reduction. A practical design for an integrated PV/T and heat pump system is presented, the integrated system is called the Photovoltaic-Indirect Expansion Solar Assisted Heat Pump (PV-IESAHP) system, which uses the heat energy supplied by PV/T as an evaporating heat source and can achieve high coefficient of performance(COP). It is essential to master the completed design idea and thermodynamic analysis method for the integration of PV/T and heat pump. In this study a kind of theoretical and matching performance model of the PV-IESAHP system is established, and a series of experiments were conducted to study the performance of the heat-pipe type PV/T experimental system and heat hump experimental system. Moreover, energy and energy analyses were used to investigate the performance of the systems. The results show that the COP of the PV-IESAHP system is about 4.0, and the energy efficiency about 0.05, which not only implies that the PV-IESAHP system has a significant energy-saving potential, but also will provide a theoretical basis for the application and parameters design of the PV-IESAHP system in the future.

  2. Theoretical study of the binding nature of glassy carbon with nickel(II) phthalocyanine complexes

    International Nuclear Information System (INIS)

    Cortez, Luis; Berrios, Cristhian; Yanez, Mauricio; Cardenas-Jiron, Gloria I.

    2009-01-01

    A theoretical study at the semiempirical RHF/PM3(tm) level (tm: transition metal) of the binding nature between a glassy carbon (GC) cluster and a nickel(II) complex (nickel(II) phthalocyanine NiPc, nickel(II) tetrasulphophthalocyanine NiTSPc) was performed. Three types of interactions for GC...NiPc (NiTSPc) were studied: (a) through an oxo (O) bridge, (b) through an hydroxo (OH) bridge, and (c) non-bridge. One layer (NiPc, NiTSPc) and two layers (NiPc...NiPc) of complex were considered. The binding energy calculated showed that in both cases NiPc and NiTSPc, the oxo structures are more stable than the hydroxo ones, and than the non-bridge systems. Charge analysis (NAO) predicted that GC gained more electrons in an oxo structure than in the analogues hydroxo. The theoretical results showed an agreement with the experimental data available, an oxo binding between GC and a nickel complex (NiPc, NiTSPc) in aqueous alkaline solutions is formed.

  3. Final state effects in photoemission studies of Fermi surfaces

    International Nuclear Information System (INIS)

    Kurtz, Richard L; Browne, Dana A; Mankey, Gary J

    2007-01-01

    Photoelectron spectroscopy is one of the most important methods for extracting information about the Fermi surface (FS) of materials. An electron photoexcited from the FS is emitted from the crystal conserving the parallel momentum, k parallel , while the perpendicular momentum k perpendicular is reduced due to the surface potential barrier. A simple interpretation of the process assumes the final state is free-electron-like allowing one to 'map' the detected photoelectron back to its initial k momentum. There are multiple final state effects that can complicate the interpretation of photoelectron data and these effects are reviewed here. These can involve both energy and k broadening, which can give rise to shadow or ghost FS contours, scattering and final state diffraction effects that modify intensities, and matrix element effects which reflect the symmetries of the states involved and can be highly dependent on photon polarization. These matrix elements result in contours of photoelectron intensity that follow the dispersion in k-space of the initial state, the FS, and the final state. Locations where intensities go to zero due to matrix element and symmetry effects can result in gaps where FS contours 'disappear'. Recognition that these effects can play a significant role in determining the measured angular distributions is crucial in developing an informed model of where the FS contours actually lie in relation to measured intensity contours

  4. Expanded clay hot mix study : final report: part I.

    Science.gov (United States)

    1969-04-01

    This is part I of a two part final report on expanded clay hot mix to: (1) evaluate the use of various expanded clay bituminous mixtures under high traffic counts, (2) accumulate through experience testing, suitable information on the physical proper...

  5. Microbial processes in the final repository, the silo part. Theoretical approach and preliminary experiments on the biodegradation of bitumen. Part 1

    International Nuclear Information System (INIS)

    Roffey, R.; Hjalmarsson, K.

    1984-01-01

    On Commission of SKBF/KBS the microbial processes that are likely to occur in the silo part of SFR, the final repository for medium- and low-level nuclear wastes, have been put together. The experimental studies concerning microbial degradation of bitumen are described. From a microbial point of view it is the biodegradation of bitumen that constitutes the greatest risk in the silo part of SFR. The degradation, aerobic as well as anaerobic, leads to production of carbon dioxide which might cause a decrease in pH to such an extent that hydrogen-gas producing corrosion of metal could occur. This production of gas can cause an increase in internal pressure of the repository. A culture of bacteria able to degrade bitumen aerobically has been enriched. Uptil now no culture degrading bitumen under anaerobic conditions have been obtained. When making a risk assessment of the SFR at the present time it is not possible to completely disregard the microbial activity. An account is also given for some international contacts in this area. 11 references

  6. In vitro drug interaction of levocetirizine and diclofenac: Theoretical and spectroscopic studies

    Science.gov (United States)

    Abo Dena, Ahmed S.; Abdel Gaber, Sara A.

    2017-06-01

    Levocetirizine dihydrochloride is known to interact with some anti-inflammatory drugs. We report here a comprehensive integrated theoretical and experimental study for the in vitro drug interaction between levocetirizine dihydrochloride (LEV) and diclofenac sodium (DIC). The interaction of the two drugs was confirmed by the molecular ion peak obtained from the mass spectrum of the product. Moreover, FTIR and 1HNMR spectra of the individual drugs and their interaction product were inspected to allocate the possible sites of interaction. In addition, quantum mechanical DFT calculations were performed to search for the interaction sites and to verify the types of interactions deduced from the spectroscopic studies such as charge-transfer and non-bonding π-π interactions. It was found that the studied drugs interact with each other in aqueous solution via four types of interactions, namely, ion-pair formation, three weak hydrogen bonds, non-bonding π-π interactions and charge-transfer from DIC to LEV.

  7. Theoretical study of the electromechanical efficiency of a loaded tubular dielectric elastomer actuator

    DEFF Research Database (Denmark)

    Rechenbach, Björn; Willatzen, Morten; Lassen, Benny

    2016-01-01

    The electromechanical efficiency of a loaded tubular dielectric elastomer actuator (DEA) is investigated theoretically. In previous studies, the external system, on which the DEA performs mechanical work, is implemented implicitly by prescribing the stroke of the DEA in a closed operation cycle....... Here, a more generic approach, modelling the external system by a frequency-dependent mechanical impedance which exerts a certain force on the DEA depending on its deformation, is chosen. It admits studying the dependence of the electromechanical efficiency of the DEA on the external system. A closed...... operation cycle is realized by exciting the DEA electrically by a sinusoidal voltage around a bias voltage. A detailed parametric study shows that the electromechanical efficiency is highly dependent on the frequency, amplitude, and bias of the excitation voltage and the mechanical impedance of the external...

  8. Theoretical study of the structure and reactivity of lanthanide and actinide based organometallic complexes

    International Nuclear Information System (INIS)

    Barros, N.

    2007-06-01

    In this PhD thesis, lanthanide and actinide based organometallic complexes are studied using quantum chemistry methods. In a first part, the catalytic properties of organo-lanthanide compounds are evaluated by studying two types of reactions: the catalytic hydro-functionalization of olefins and the polymerisation of polar monomers. The reaction mechanisms are theoretically determined and validated, and the influence of possible secondary non productive reactions is envisaged. A second part focuses on uranium-based complexes. Firstly, the electronic structure of uranium metallocenes is analysed. An analogy with the uranyl compounds is proposed. In a second chapter, two isoelectronic complexes of uranium IV are studied. After validating the use of DFT methods for describing the electronic structure and the reactivity of these compounds, it is shown that their reactivity difference can be related to a different nature of chemical bonding in these complexes. (author)

  9. Theoretical study of Ce2+ cubic centres in alkaline earth fluoride crystals

    International Nuclear Information System (INIS)

    Popov, N.; Mysovsky, A.; Shendrik, R.; Radzhabov, E.

    2016-01-01

    In this paper we present theoretical study of Ce 2+ impurity centres in alkaline earth fluoride crystals (CaF 2 , SrF 2 ). Only cubic configurations of centres were considered. Electronic levels and related properties were studied using CASSCF/CASPT2 approach within embedded-cluster formalism including scalar relativistic corrections and spin-orbital interaction. Calculated absorption spectra for Ce 2+ in CaF 2 and SrF 2 are in good agreement with experimental data. For both crystals the ground state of Ce 2+ ion has predominantly 4f 1 5d 1 singlet character. - Highlights: • Ab inito study of Ce 2+ impurity centres in alkaline earth fluoride crystals. • Calculated Ce 2+ ground state in CaF 2 and SrF 2 is predominantly 4f 1 5d 1 singlet. • Calculated absorption spectra are in good agreement width experimental data.

  10. Study of cognitive sphere in children and adolescents with congenital myopathy (theoretical review

    Directory of Open Access Journals (Sweden)

    V. A. Erokhina

    2013-08-01

    Full Text Available This paper presents an analysis of current approaches to the study of states of higher mental functions in children and adolescents suffering from various forms of hereditary myopathies. The aim of this work is to study the theoretical rationale and the possibility of specific disorders of mental function in children and adolescents with congenital myopathies. To achieve this objective during the study it was necessary to solve the following problems: give a description of the various groups and forms of congenital myopathies, their clinical characteristics; justify the possibility of considering the hereditary myopathies as a factor in the formation of changes in visual-spatial activities and thinking; evaluate the possibility to use complex neuropsychological psycho-diagnostic techniques for investigating the state of the higher mental functions of children with congenital myopathies. The possibility of neuropsychological correction for this category of patients is discussed also.

  11. Experimental and theoretical studies of a pyrazole-thiazolidin-2,4-di-one hybrid

    Science.gov (United States)

    Mushtaque, Md.; Avecilla, Fernando; Haque, Ashanul; Perwez, Ahmad; Khan, Md. Shahzad; Rizvi, M. Moshahid Alam

    2017-08-01

    The present work describes synthesis, characterization and biological evaluations of a hybrid compound 10 composed of two intriguing scaffolds pyrazole and thiazolidin-2,4-di-one. The title compound was obtained via multi-step reaction and characterized by a number of techniques (viz. IR, UV-Visible, 1H-NMR, 13C-NMR and MS) including X-ray crystallography. The structural and photophysical data of compound 10 were well supported by theoretical calculations performed at density functional (DFT) level. In-vitro anticancer studies on different human cancer cell lines indicated moderate to low activity of the compounds. The molecular target of the compound was predicted through in-silico studies. Finding of the studies are presented herein.

  12. An experimental and theoretical study of reaction steps relevant to the methanol-to-hydrocarbons reaction

    Energy Technology Data Exchange (ETDEWEB)

    Svelle, Stian

    2004-07-01

    The primary objective of the present work is to obtain new insight into the reaction mechanism of the zeolite catalyzed methanol-to-hydrocarbons (MTH) reaction. It was decided to use both experimental and computational techniques to reach this goal. An investigation of the n-butene + methanol system was therefore initiated. Over time, it became apparent that it was possible to determine the rate for the methylation of n-butene by methanol. The ethene and propene systems were therefore reexamined in order to collect kinetic information also for those cases. With the development of user-friendly quantum chemistry programs such as the Gaussian suite of programs, the possibility of applying quantum chemical methods to many types of problems has become readily available even for non-experts. When performing mechanistic studies, there is quite often a considerable synergy effect when combining experimental and computational approaches. The methylation reactions mentioned above turned out to be an issue well suited for quantum chemical investigations. The incentive for examining the halomethane reactivity was the clear analogy to the MTH reaction system. Alkene dimerization was also a reaction readily examined with quantum chemistry. As discussed in the introduction of this thesis, polymethylbenzenes, or their cationic counterparts, are suspected to be key intermediates in the MTH reaction. It was therefore decided to investigate the intrinsic reactivity of these species in the gas-phase by employing sophisticated mass spectrometric (MS) techniques in collaboration with the MS group at the Department of Chemistry, University of Oslo The data thus obtained will also be compared with results from an ongoing computational study on gas phase polymethylbenzenium reactivity. 6 papers presenting various studies are included. The titles are: 1) A Theoretical Investigation of the Methylation of Alkenes with Methanol over Acidic Zeolites. 2) A Theoretical Investigation of the

  13. Theoretical study of sensitizer candidates for dye-sensitized solar cells: peripheral substituted dizinc pyrazinoporphyrazine-phthalocyanine complexes.

    Science.gov (United States)

    Zarate, Ximena; Schott, Eduardo; Gomez, Tatiana; Arratia-Pérez, Ramiro

    2013-01-17

    We have carried out a theoretical study of the geometrical and electronic structures of a family of planar dimers constituted by zinc(II) pyrazinoporphyrazine and zinc(II) phthalocyanine with peripheral electron-donating and electron-withdrawing substituents R [where R = -OH (1), -C(CH(3))(3) (2), -CH(3) (3), -C(6)H(5) (4), -H (5), -CO(2)H (7), -NO(2) (7), and -PO(3)H(2) (8)]. The complexes are connected by varying the bridge (B) ligand, where, in 1-9, B is -CH= and, in 10-12, B is -N=, -O-, and -S-, respectively. The -CO(2)H group was included in complexes identified as 9-12. This was done because of the known properties of this group in acting as an anchor to adsorb a dye onto a semiconductor oxide. The aim of this work was to provide a useful theoretical basis for the design and screening of new potential dye candidates to be used in these devices, based on the properties of the dyes suitable for their good performance in solar cells, such as frontier molecular orbital spatial distributions; charge-separated states in the electronic transitions in the visible region of the spectrum; and importantly, the energy diagram of the frontier MOs of these dyes and the conduction band (CB) of the semiconductor, where the LUMO energy levels that are above of the CB suggest which dyes are capable of electron injection into TiO(2). In this sense, it is expected that complexes 1-5 and 9-12 should be very promising dyes to act as sensitizers. Finally, a linear correlation was found between the HOMO and LUMO energies of all of the systems and the Hammett constants, where these molecular orbitals become more stable when R is more electron-withdrawing.

  14. Optimal Pulse Configuration Design for Heart Stimulation. A Theoretical, Numerical and Experimental Study.

    Science.gov (United States)

    Hardy, Neil; Dvir, Hila; Fenton, Flavio

    Existing pacemakers consider the rectangular pulse to be the optimal form of stimulation current. However, other waveforms for the use of pacemakers could save energy while still stimulating the heart. We aim to find the optimal waveform for pacemaker use, and to offer a theoretical explanation for its advantage. Since the pacemaker battery is a charge source, here we probe the stimulation current waveforms with respect to the total charge delivery. In this talk we present theoretical analysis and numerical simulations of myocyte ion-channel currents acting as an additional source of charge that adds to the external stimulating charge for stimulation purposes. Therefore, we find that as the action potential emerges, the external stimulating current can be reduced accordingly exponentially. We then performed experimental studies in rabbit and cat hearts and showed that indeed exponential truncated pulses with less total charge can still induce activation in the heart. From the experiments, we present curves showing the savings in charge as a function of exponential waveform and we calculated that the longevity of the pacemaker battery would be ten times higher for the exponential current compared to the rectangular waveforms. Thanks to Petit Undergraduate Research Scholars Program and NSF# 1413037.

  15. Theoretical study of support effect of Au catalyst for glucose oxidation of alkaline fuel cell anode

    Energy Technology Data Exchange (ETDEWEB)

    Ishimoto, Takayoshi, E-mail: ishimoto@ifrc.kyushu-u.ac.jp [Frontier Energy Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Hamatake, Yumi [Frontier Energy Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Kazuno, Hiroki; Kishida, Takayuki [OLYMPUS Corporation, 2-3 Kuboyama-cho, Hachioji-shi, Tokyo 192-8512 (Japan); Koyama, Michihisa, E-mail: koyama@ifrc.kyushu-u.ac.jp [Frontier Energy Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); International Institute for Carbon-Neutral Energy Research, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2015-01-01

    Highlights: • The catalytic activity of Au in alkaline solution is studied theoretically. • Carbon and oxide materials are used to estimate support effect for glucose oxidation. • The glucose oxidation on SnO{sub 2}(1 1 0) supported Au catalyst shows high activity. • The charge transfer from Au catalyst to support materials is dominant. - Abstract: We theoretically analyzed the glucose oxidation reaction mechanism and reaction activity of Au catalyst supported by carbon (graphite(0 0 0 1), (101{sup ¯}0), and (112{sup ¯}0)) and oxide (ZrO{sub 2}(1 1 1) and SnO{sub 2}(1 1 0)) in alkaline solution environment by using density functional theory method. We observed large stabilization of Au catalyst on support materials due to the electron transfer in the case of graphite(112{sup ¯}0) and SnO{sub 2}(1 1 0) systems. The catalytic activity for glucose oxidation reaction over Au supported by graphite(101{sup ¯}0) and (112{sup ¯}0) is calculated to be low in comparison with those of unsupported system. We found that SnO{sub 2}(1 1 0) supported Au catalyst shows high activity toward the glucose oxidation. One of the main factors for the observed high catalytic activity is charge transfer from Au catalyst to support materials. When the atomic charge of Au catalyst becomes positive by the support effect, the activity of glucose oxidation reaction on Au catalyst is improved.

  16. Further theoretical studies of modified cyclone separator as a diesel soot particulate emission arrester.

    Science.gov (United States)

    Mukhopadhyay, N; Bose, P K

    2009-10-01

    Soot particulate emission reduction from diesel engine is one of the most emerging problems associated with the exhaust pollution. Diesel particulate filters (DPF) hold out the prospects of substantially reducing regulated particulate emissions but the question of the reliable regeneration of filters still remains a difficult hurdle to overcome. Many of the solutions proposed to date suffer from design complexity, cost, regeneration problem and energy demands. This study presents a computer aided theoretical analysis for controlling diesel soot particulate emission by cyclone separator--a non contact type particulate removal system considering outer vortex flow, inner vortex flow and packed ceramic fiber filter at the end of vortex finder tube. Cyclone separator with low initial cost, simple construction produces low back pressure and reasonably high collection efficiencies with reduced regeneration problems. Cyclone separator is modified by placing a continuous ceramic packed fiber filter placed at the end of the vortex finder tube. In this work, the grade efficiency model of diesel soot particulate emission is proposed considering outer vortex, inner vortex and the continuous ceramic packed fiber filter. Pressure drop model is also proposed considering the effect of the ceramic fiber filter. Proposed model gives reasonably good collection efficiency with permissible pressure drop limit of diesel engine operation. Theoretical approach is predicted for calculating the cut size diameter considering the effect of Cunningham molecular slip correction factor. The result shows good agreements with existing cyclone and DPF flow characteristics.

  17. Experimental and theoretical study on field emission properties of zinc oxide nanoparticles decorated carbon nanotubes

    International Nuclear Information System (INIS)

    Li Xin; Zhou Wei-Man; Liu Wei-Hua; Wang Xiao-Li

    2015-01-01

    Field emission properties of zinc oxide (ZnO) nanoparticles (NPs) decorated carbon nanotubes (CNTs) are investigated experimentally and theoretically. CNTs are in situ decorated with ZnO NPs during the growth process by chemical vapor deposition using a carbon source from the iron phthalocyanine pyrolysis. The experimental field emission test shows that the ZnO NP decoration significantly improves the emission current from 50 μA to 275 μA at 550 V and the reduced threshold voltage from 450 V to 350 V. The field emission mechanism of ZnO NPs on CNTs is theoretically studied by the density functional theory (DFT) combined with the Penn–Plummer method. The ZnO NPs reconstruct the ZnO–CNT structure and pull down the surface barrier of the entire emitter system to 0.49 eV so as to reduce the threshold electric field. The simulation results suggest that the presence of ZnO NPs would increase the LDOS near the Fermi level and increase the emission current. The calculation results are consistent with the experiment results. (paper)

  18. The structural, electronic and spectroscopic properties of 4FPBAPE molecule: Experimental and theoretical study

    Science.gov (United States)

    Tanış, Emine; Babur Sas, Emine; Kurban, Mustafa; Kurt, Mustafa

    2018-02-01

    The experimental and theoretical study of 4-Formyl Phenyl Boronic Acid Pinacol Ester (4FPBAPE) molecule were performed in this work. 1H, 13C NMR and UV-Vis spectra were tested in dimethyl sulfoxide (DMSO). The structural, spectroscopic properties and energies of 4FPBAPE were obtained for two potential conformers from density functional theory (DFT) with B3LYP/6-311G (d, p) and CAM-B3LYP/6-311G (d, p) basis sets. The optimal geometry of those structures was obtained according to the position of oxygen atom upon determining the scan coordinates for each conformation. The most stable conformer was found as the A2 form. The fundamental vibrations were determined based on optimized structure in terms of total energy distribution. Electronic properties such as oscillator strength, wavelength, excitation energy, HOMO, LUMO and molecular electrostatic potential and structural properties such as radial distribution functions (RDF) and probability density depending on coordination number are presented. Theoretical results of 4-FPBAPE spectra were found to be compatible with observed spectra.

  19. Theoretical and experimental study of isothiazolinone adsorption onto ordered mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Mardones, Lucas E.; Legnoverde, María Soledad [Centro de Investigación y Desarrollo en Ciencias Aplicadas (CINDECA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata − CONICET Calle 47 N°257, B1900AJK La Plata (Argentina); Simonetti, Sandra [Departamento de Física and IFISUR, Universidad Nacional del Sur-CONICET, Av. Alem 1253, 8000 Bahía Blanca (Argentina); Departamentos de Ciencias Básicas e Ingeniería Mecánica, Universidad Tecnológica Nacional, 11 de Abril 461, 8000 Bahía Blanca (Argentina); Basaldella, Elena I., E-mail: ebasaldella@hotmail.com [Centro de Investigación y Desarrollo en Ciencias Aplicadas (CINDECA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata − CONICET Calle 47 N°257, B1900AJK La Plata (Argentina)

    2016-12-15

    Highlights: • The pore size of the silica increase by aging the reaction solution. • The theoretical study confirms that CMIT/MIT is adsorbed on the silica surface. • The adsorption capacities increase when the particle size becomes smaller. - Abstract: Mesoporous silica SBA-15 particles were synthesized in order to evaluate their effectiveness as encapsulating agents for a commercial biocide composed of a mixture of methylisothiazolinone and chloromethylisothiazolinone (MIT/CMIT). Three powdered samples of silica particles having different textural properties, sizes and morphologies were hydrothermally obtained and then characterized by SEM, TEM, SAXS, and nitrogen adsorption–desorption measurements. Adsorption of the biocide on the prepared materials was investigated, and the results showed that adsorption capacities increase as the particle size becomes smaller. Higher biocide amounts were also retained on particles having increased pore size and pore volume. Additionally, a most probable interaction mechanism between MIT/CMIT and SBA-15 is proposed on the basis of molecular modeling calculations. The theoretical approach indicates that two adsorption geometries with comparable minimum levels of strength can be adopted by the biocide: planar adsorption when the biocide molecule rings are adsorbed on the silica surface and vertical adsorption when the O atom of the MIT/CMIT interacts with the H atom of silanols.

  20. Theoretical study on the inverse modeling of deep body temperature measurement

    International Nuclear Information System (INIS)

    Huang, Ming; Chen, Wenxi

    2012-01-01

    We evaluated the theoretical aspects of monitoring the deep body temperature distribution with the inverse modeling method. A two-dimensional model was built based on anatomical structure to simulate the human abdomen. By integrating biophysical and physiological information, the deep body temperature distribution was estimated from cutaneous surface temperature measurements using an inverse quasilinear method. Simulations were conducted with and without the heat effect of blood perfusion in the muscle and skin layers. The results of the simulations showed consistently that the noise characteristics and arrangement of the temperature sensors were the major factors affecting the accuracy of the inverse solution. With temperature sensors of 0.05 °C systematic error and an optimized 16-sensor arrangement, the inverse method could estimate the deep body temperature distribution with an average absolute error of less than 0.20 °C. The results of this theoretical study suggest that it is possible to reconstruct the deep body temperature distribution with the inverse method and that this approach merits further investigation. (paper)

  1. Size-dependent decomposition temperature of nanoparticles: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shanshan; Cui, Zixiang; Xia, Xiaoyan; Xue, Yongqiang, E-mail: xyqlw@126.com

    2014-12-01

    Thermal decomposition of nanomaterials is often involved in the preparation and applications of nanomaterials, of which decomposition temperature can be surprisingly different from corresponding bulk materials. However, there is a lack of theoretical and experimental investigation on the relationship between the decomposition temperature and nanoparticle size. In present study, the relation between the decomposition temperature and the size of nanoparticles was derived theoretically, which indicates that the decomposition temperature decreases with the size of the nanoparticles decreasing, and there is a linear relationship between the decomposition temperature and the reciprocal of the particle size when the radius is bigger than 10 nm. Thermal decomposition experiments of nano-calcium carbonate with different sizes were carried out by thermo-gravimetric (TG), the onset decomposition temperatures (T{sub onset}) and the temperature of the DTG peaks (T{sub max}) were measured and both of them present well liner relationship with the reciprocal of the particle size. The depress regularity of the onset decomposition temperature of nano-calcium carbonate agrees with the derived thermodynamic relationship. This thermodynamic theory provides a quantitative description for the decomposition temperature of nanoparticles, also it can be used to predict and explain the thermal decomposition behavior of nanomaterials.

  2. Theoretical Study on Synchronous Characterization of Surface and Interfacial Mechanical Properties of Thin-Film/Substrate Systems with Residual Stress Based on Pressure Blister Test Technique

    Directory of Open Access Journals (Sweden)

    Zhi-xin Yang

    2018-01-01

    Full Text Available In this study, based on the pressure blister test technique, a theoretical study on the synchronous characterization of surface and interfacial mechanical properties of thin-film/substrate systems with residual stress was presented, where the problem of axisymmetric deformation of a blistering film with initial stress was analytically solved and its closed-form solution was presented. The expressions to determine Poisson’s ratios, Young’s modulus, and residual stress of surface thin films were derived; the work done by the applied external load and the elastic energy stored in the blistering thin film were analyzed in detail and their expressions were derived; and the interfacial adhesion energy released per unit delamination area of thin-film/substrate (i.e., energy release rate was finally presented. The synchronous characterization technique presented here has theoretically made a big step forward, due to the consideration for the residual stress in surface thin films.

  3. Theoretical and Experimental Study of LiBH4-LiCl Solid Solution

    Directory of Open Access Journals (Sweden)

    Torben R. Jensen

    2012-03-01

    Full Text Available Anion substitution is at present one of the pathways to destabilize metal borohydrides for solid state hydrogen storage. In this work, a solid solution of LiBH4 and LiCl is studied by density functional theory (DFT calculations, thermodynamic modeling, X-ray diffraction, and infrared spectroscopy. It is shown that Cl substitution has minor effects on thermodynamic stability of either the orthorhombic or the hexagonal phase of LiBH4. The transformation into the orthorhombic phase in LiBH4 shortly after annealing with LiCl is for the first time followed by infrared measurements. Our findings are in a good agreement with an experimental study of the LiBH4-LiCl solid solution structure and dynamics. This demonstrates the validity of the adopted combined theoretical (DFT calculations and experimental (vibrational spectroscopy approach, to investigate the solid solution formation of complex hydrides.

  4. Theoretical studies of Pt-Ti nanoparticles for potential use as PEMFC electrocatalysts.

    Science.gov (United States)

    Jennings, Paul C; Pollet, Bruno G; Johnston, Roy L

    2012-03-07

    A theoretical investigation is presented of alloying platinum with titanium to form binary Pt-Ti nanoalloys as an alternative to the expensive pure platinum catalysts commonly used for Proton Exchange Membrane Fuel Cell cathode electrocatalysts. Density Functional Theory calculations are performed to investigate compositional effects on structural properties as well as Oxygen Reduction Reaction kinetics and poisoning effects. High symmetry A(32)-B(6) clusters are studied to investigate structural properties. From these structures binding energies of hydroxyl and carbon monoxide are studied on a range of sites on the surface of the clusters. Promising results are obtained suggesting that the bimetallic Pt-Ti nanoalloys may exhibit enhanced properties compared to pure platinum catalysts.

  5. Theoretical and Experimental Studies of New Polymer-Metal High-Dielectric Constant Nanocomposites

    Science.gov (United States)

    Ginzburg, Valeriy; Elwell, Michael; Myers, Kyle; Cieslinski, Robert; Malowinski, Sarah; Bernius, Mark

    2006-03-01

    High-dielectric-constant (high-K) gate materials are important for the needs of electronics industry. Most polymers have dielectric constant in the range 2 materials with K > 10 it is necessary to combine polymers with ceramic or metal nanoparticles. Several formulations based on functionalized Au-nanoparticles (R ˜ 5 -— 10 nm) and PMMA matrix polymer are prepared. Nanocomposite films are subsequently cast from solution. We study the morphology of those nanocomposites using theoretical (Self-Consistent Mean-Field Theory [SCMFT]) and experimental (Transmission Electron Microscopy [TEM]) techniques. Good qualitative agreement between theory and experiment is found. The study validates the utility of SCMFT as screening tool for the preparation of stable (or at least metastable) polymer/nanoparticle mixtures.

  6. A theoretical and mass spectrometry study of the fragmentation of mycosporine-like amino acids

    Science.gov (United States)

    Cardozo, Karina H. M.; Vessecchi, Ricardo; Carvalho, Valdemir M.; Pinto, Ernani; Gates, Paul J.; Colepicolo, Pio; Galembeck, Sérgio E.; Lopes, Norberto P.

    2008-06-01

    In the present study, the mycosporine-like amino acids (MAAs) were isolated from the marine red alga Gracilaria tenuistipitata and analysed by high-resolution accurate-mass sequential mass spectrometry (MSn). In addition to the proposed fragmentation mechanism based on the MSn analysis, it is clearly demonstrated that the elimination of mass 15 is a radical processes taking place at the methoxyl substituent of the double bond. This characteristic loss of a methyl radical was studied by theoretical calculations and the homolytic cleavage of the OC bond is suggested to be dependent on the bond weakening. The protonation site of the MAAs was indicated by analysis of the Fukui functions and the relative Gibbs energies of the several possible protonated forms.

  7. Activity systems modeling as a theoretical lens for social exchange studies

    Directory of Open Access Journals (Sweden)

    Ernest Jones

    2016-01-01

    Full Text Available The social exchange perspective seeks to acknowledge, understand and predict the dynamics of social interactions. Empirical research involving social exchange constructs have grown to be highly technical including confirmatory factor analysis to assess construct distinctiveness and structural equation modeling to assess construct causality. Each study seemingly strives to assess how underlying social exchange theoretic constructs interrelate. Yet despite this methodological depth and resultant explanatory and predictive power, a significant number of studies report findings that, once synthesized, suggest an underlying persistent threat of conceptual or construct validity brought about by a search for epistemological parsimony. Further, it is argued that a methodological approach that embraces inherent complexity such as activity systems modeling facilitates the search for simplified models while not ignoring contextual factors.

  8. Characterization of electronic structure and physicochemical properties of antiparasitic nifurtimox analogues: A theoretical study

    Science.gov (United States)

    Soriano-Correa, Catalina; Raya, A.; Esquivel, Rodolfo O.

    American trypanosomiasis, also known as Chagas' disease, is caused by Trypanosoma cruzi (T. cruzi). It is well known that trypanosomes, and particularly T. cruzi, are highly sensitive towards oxidative stress, i.e., to compounds than are able to produce free radicals. Generally, nifurtimox (NFX) and benznidazol are most effective in the acute phase of the disease; therefore, nitroheterocycles constitute good models to design other nitrocompounds with specific biological characteristics. Thus, we have performed an ab initio study at the Hartree-Fock and Density Functional Theory levels of theory of several NFX analogues recently synthesized, to characterize them by obtaining their electronic, structural, and physicochemical properties, which might be linked to the observed antichagasic activity. The antitrypanosomal activity scale previously reported for the NFX analogues studied in this work is in good agreement with our theoretical results, from which we can conclude that the activity seems to be related to the reactivity along with the acidity observed for the most active molecules.

  9. Theoretical study on the effect of solvents in chlorophyll solution for Dye-Sensitized Solar Cell

    Science.gov (United States)

    Rodhi Faiz, Mohamad; Widhiyanuriyawan, Denny; Siswanto, Eko; Wardana, I. N. G.

    2018-01-01

    Using the density functional theory (DFT) and time-dependent DFT (TD-DFT), we have theoretically studied the electron excitation and absorption spectra of chlorophyll solution with several solvents for Dye-Sensitized Solar Cell (DSSC) application. The solvents were aceton, acetonitrile, DMSO, ethanol, hexane, methanol, THF and water. Also, energy level, oscilator strength, light harvesting efficiency and electron injection have been investigated. The studied dye in the presence of the solvents showed a smaller gap of the highest occupied molecular orbital (HOMO) - the lowest unoccupied molecular orbital (LUMO) and a higher light harvesting, oscillator strength and red shift in the absorption spectra. These changes facilitate the charge transfer phenomena in the nano structure of the chlorophyll as dye and improve the solar cell efficiency.

  10. Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Ahamad, Ishtiaque [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India); Prasad, Rajendra [Department of Chemistry, SGB Amravati University, Amravati 444 602 (India); Quraishi, M.A., E-mail: maquraishi@rediffmail.co [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India)

    2010-09-15

    Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E{sub a}) and different thermodynamic parameters such as adsorption equilibrium constant (K{sub ads}), free energy of adsorption ({Delta}G{sub ads}{sup o}), adsorption enthalpy ({Delta}H{sub ads}{sup o}) and adsorption entropy ({Delta}S{sub ads}{sup o}) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

  11. Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Ahamad, Ishtiaque; Prasad, Rajendra; Quraishi, M.A.

    2010-01-01

    Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E a ) and different thermodynamic parameters such as adsorption equilibrium constant (K ads ), free energy of adsorption (ΔG ads o ), adsorption enthalpy (ΔH ads o ) and adsorption entropy (ΔS ads o ) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

  12. Theoretical study on the thermal and optical features of a diode side-pumped alkali laser

    Science.gov (United States)

    Han, Juhong; Liu, Xiaoxu; Wang, Hongyuan; Cai, He; An, Guofei; Zhang, Wei; Wang, You

    2018-03-01

    As one of the most hopeful candidates to achieve high power performances, a diode-pumped alkali laser (DPAL) has attracted a lot of attention in the last decade. Comparing with a diode end-pumped alkali laser (DEPAL), a diode side-pumped alkali laser (DSPAL) has great potentiality to realize an even-higher output of alkali lasers. However, there are few related researching studies concern DSPAL. In this paper, we introduce a theoretical model to investigate the physical features of a double-directions side-pumped alkali laser. The distributions of the population density, temperature, and absorption power at the cross section of a vapor cell are systematically studied. The analyses should be valuable for design of a steady high-powered DPAL.

  13. FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Halverson, N

    2008-09-30

    In February 2000, the United States Environmental Protection Agency (EPA) Region 4 issued a proposed Total Maximum Daily Load (TMDL) for total mercury in the middle and lower Savannah River. The initial TMDL, which would have imposed a 1 ng/l mercury limit for discharges to the middle/lower Savannah River, was revised to 2.8 ng/l in the final TMDL released in February 2001. The TMDL was intended to protect people from the consumption of contaminated fish, which is the major route of mercury exposure to humans. The most bioaccumulative form of mercury is methylmercury, which is produced in aquatic environments by the action of microorganisms on inorganic mercury. Because of the environmental and economic significance of the mercury discharge limits that would have been imposed by the TMDL, the Savannah River Site (SRS) initiated several studies concerning: (1) mercury in SRS discharges, SRS streams and the Savannah River, (2) mercury bioaccumulation factors for Savannah River fish, (3) the use of clams to monitor the influence of mercury from tributary streams on biota in the Savannah River, and (4) mercury in rainwater falling on the SRS. The results of these studies are presented in detail in this report. The first study documented the occurrence, distribution and variation of total and methylmercury at SRS industrial outfalls, principal SRS streams and the Savannah River where it forms the border with the SRS. All of the analyses were performed using the EPA Method 1630/31 ultra low-level and contaminant-free techniques for measuring total and methylmercury. Total mercury at National Pollutant Discharge Elimination System (NPDES) outfalls ranged from 0.31-604 ng/l with a mean of 8.71 ng/l. Mercury-contaminated groundwater was the source for outfalls with significantly elevated mercury concentrations. Total mercury in SRS streams ranged from 0.95-15.7 ng/l. Mean total mercury levels in the streams varied from 2.39 ng/l in Pen Branch to 5.26 ng/l in Tims Branch

  14. Adsorption of uranium composites onto saltrock oxides - experimental and theoretical study.

    Science.gov (United States)

    Ivanova, Bojidarka; Spiteller, Michael

    2014-09-01

    The study encompassed experimental mass spectrometric and theoretical quantum chemical studies on adsorption of uranium species in different oxidation states of the metal ion, and oxides of UxOy(n+) type, where x = 1 or 3, y = 2 or 8, and n = 0, 1 or 2 onto nanosize-particles of saltrock oxides MO (M = Mg(II), Ca(II), Ni(II), Co(II), Sr(II) or Ba(II)), M2Oy (M = Au(III) or Ag(I), y = 3 or 1) silicates 3Al2O3.2SiO2, natural kaolinite (Al2O2·2SiO2·2H2O), illite (K0.78Ca0.02Na0.02(Mg0.34Al1.69Fe(III)0.02)[Si3.35Al0.65]O10(OH)2·nH2O), CaSiO3, 3MgO·4SiO2,H2O, and M(1)M(2)(SiO4)X2 (M(1) = M(2) = Al or M(1) = K, M(2) = Al, X = F or Cl), respectively. The UV-MALDI-Orbitrap mass spectrometry was utilized in solid-state and semi-liquid colloidal state, involving the laser ablation at λex = 337.2 nm. The theoretical modeling and experimental design was based on chemical-, physico-chemical, physical and biological processes involving uranium species under environmental conditions. Therefore, the results reported are crucial for quality control and monitoring programs for assessment of radionuclide migration. They impact significantly the methodology for evaluation of human health risk from radioactive contamination. The study has importance for understanding the coordination and red-ox chemistry of uranium compounds as well. Due to the double nature of uranium between rare element and superconductivity like materials as well as variety of oxidation states ∈ (+1)-(+6), the there remain challenging areas for theoretical and experimental research, which are of significant importance for management of nuclear fuel cycles and waste storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Experimental and theoretical study of the Nd:YAG laser removal of beeswax on Galician granite at 355 nm

    Science.gov (United States)

    Pan, Aldara; Rebollar, Esther; Conde, J. Carlos; Lusquiños, Fernando; Chiussi, Stefano; León, Betty

    2010-09-01

    Beeswax coatings applied to seal off the granitic surfaces of many monuments have resulted in detrimental effects with time passing. Conservation procedures must be carried out in a selective way, removing the beeswax without any degradation of the stone. In this study we present an experimental analysis of the removal of beeswax using a Nd:YAG laser at a wavelength of 355 nm which is absorbed weakly by the beeswax. For this reason, an important percentage of the laser radiation reaches the granite substrate and the influence of the layer thickness must be studied. At each laser fluence, for single-pulse irradiation we find a maximum thickness for complete removal of the film. For thicker layers, the beeswax is not removed and additional effects such as color changes and thickness increase are observed. The experimental results suggest that a photomechanical mechanism is dominant and that granite absorption plays a fundamental role. Multiple-pulse irradiation is also performed to determine the optimal parameters for laser cleaning. Finally, infrared thermography measurements allow for the determination of the granite surface temperature after laser irradiation and theoretical calculations allow one to estimate the absorption behavior of granite at 355 and to explain the results obtained.

  16. Theoretical Studies of the Electronic Structure of the Compounds of the Actinide Elements

    International Nuclear Information System (INIS)

    Kaltsoyannis, Nikolas; Hay, P.J.; Li, Jun; Blaudeau, Jean-Philippe; Bursten, Bruce E.

    2006-01-01

    In this chapter, we will present an overview of the theoretical and computational developments that have increased our understanding of the electronic structure of actinide-containing molecules and ions. The application of modern electronic structure methodologies to actinide systems remains one of the great challenges in quantum chemistry; indeed, as will be discussed below, there is no other portion of the periodic table that leads to the confluence of complexity with respect to the calculation of ground- and excited-state energies, bonding descriptions, and molecular properties. But there is also no place in the periodic table in which effective computational modeling of electronic structure can be more useful. The difficulties in creating, isolating, and handling many of the actinide elements provide an opportunity for computational chemistry to be an unusually important partner in developing the chemistry of these elements. The importance of actinide electronic structure begins with the earliest studies of uranium chemistry and predates the discovery of quantum mechanics. The fluorescence of uranyl compounds was observed as early as 1833, a presage of the development of actinometry as a tool for measuring photochemical quantum yields. Interest in nuclear fuels has stimulated tremendous interest in understanding the properties, including electronic properties, of small actinide-containing molecules and ions, especially the oxides and halides of uranium and plutonium. The synthesis of uranocene in 1968 led to the flurry of activity in the organometallic chemistry of the actinides that continues today. Actinide organometallics (or organoactinides) are nearly always molecular systems and are often volatile, which makes them amenable to an arsenal of experimental probes of molecular and electronic structure (Marks and Fischer, 1979). Theoretical and computational studies of the electronic structure of actinide systems have developed in concert with the experimental

  17. CONTENT ANALYSIS, DISCOURSE ANALYSIS, AND CONVERSATION ANALYSIS: PRELIMINARY STUDY ON CONCEPTUAL AND THEORETICAL METHODOLOGICAL DIFFERENCES

    Directory of Open Access Journals (Sweden)

    Anderson Tiago Peixoto Gonçalves

    2016-08-01

    Full Text Available This theoretical essay aims to reflect on three models of text interpretation used in qualitative research, which is often confused in its concepts and methodologies (Content Analysis, Discourse Analysis, and Conversation Analysis. After the presentation of the concepts, the essay proposes a preliminary discussion on conceptual and theoretical methodological differences perceived between them. A review of the literature was performed to support the conceptual and theoretical methodological discussion. It could be verified that the models have differences related to the type of strategy used in the treatment of texts, the type of approach, and the appropriate theoretical position.

  18. Photoelectron Spectroscopy and Theoretical Studies of Anion-pi Interactions: Binding Strength and Anion Specificity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian; Zhou, Bin; Sun, Zhenrong; Wang, Xue B.

    2015-01-01

    Proposed in theory and confirmed to exist, anion–π interactions have been recognized as new and important non-covalent binding forces. Despite extensive theoretical studies, numerous crystal structural identifications, and a plethora of solution phase investigations, intrinsic anion–π interaction strengths that are free from complications of condensed phases’ environments, have not been directly measured in the gas phase. Herein we present a joint photoelectron spectroscopic and theoretical study on this subject, in which tetraoxacalix[2]arene[2]triazine 1, an electron-deficient and cavity self-tunable macrocyclic was used as a charge-neutral molecular host to probe its interactions with a series of anions with distinctly different shapes and charge states (spherical halides Cl⁻, Br⁻, I⁻, linear thiocyanate SCN⁻, trigonal planar nitrate NO₃⁻, pyramidic iodate IO₃⁻, and tetrahedral sulfate SO₄²⁻). The binding energies of the resultant gaseous 1:1 complexes (1•Cl⁻,1•Br⁻, 1•I⁻, 1•SCN⁻, 1•NO₃⁻, 1•IO₃⁻ and 1•SO₄²⁻) were directly measured experimentally, exhibiting substantial non-covalent interactions with pronounced anion specific effects. The binding strengths of Cl⁻, NO₃⁻, IO₃⁻ with 1 are found to be strongest among all singly charged anions, amounting to ca. 30 kcal/mol, but only about 40% of that between 1 and SO₄²⁻. Quantum chemical calculations reveal that all anions reside in the center of the cavity of 1 with anion–π binding motif in the complexes’ optimized structures, where 1 is seen to be able to self-regulate its cavity structure to accommodate anions of different geometries and three-dimensional shapes. Electron density surface and natural bond orbital charge distribution analysis further support anion–π binding formation. The calculated binding energies of the anions and 1 nicely reproduce the experimentally estimated electron binding energy increase. This work

  19. Spectroscopic and theoretical study of the o-vanillin hydrazone of the mycobactericidal drug isoniazid

    Science.gov (United States)

    González-Baró, Ana C.; Pis-Diez, Reinaldo; Parajón-Costa, Beatriz S.; Rey, Nicolás A.

    2012-01-01

    A complete and detailed study of the hydrazone obtained from condensation of antituberculous isoniazid (hydrazide of the isonicotinic acid, INH) and o-vanillin (2-hydroxy-3-methoxybenzaldehyde, o-HVa) is performed. It includes structural and spectroscopic analyses, comparing experimental and theoretical results. The compound was obtained as a chloride of the pyridinic salt (INHOVA +Cl -) but it will be referred as INHOVA for the sake of simplicity. The conformational space was searched and optimized geometries were determined both in gas phase and including solvent effects. Vibrational (IR and Raman), electronic and NMR spectra were registered and assigned with the help of computational methods based on the Density Functional Theory. Isoniazid hydrazones are good candidates for therapeutic agents against tuberculosis with conserved efficiency and lower toxicity and resistance than parent INH.

  20. RECENT DEVELOPMENTS OF THE FINANCIAL REPORTING MODEL: THEORETICAL STUDIES IN REVIEW

    Directory of Open Access Journals (Sweden)

    Bonaci Carmen Giorgiana

    2011-07-01

    Full Text Available Our paper analyzes the manner in which the financial reporting model evolved towards fair value accounting. After a brief introduction into the context of financial reporting at international level, the analysis focuses on the accounting model of fair value. This is done by synthesizing main studies in accounting research literature that analyze fair value accounting through a theoretical approach. The analysis being developed relies on literature review methodology. The main purpose of the developed analysis is to synthesize main pros and cons as being documented through accounting research literature. Our findings underline both the advantages and shortcomings of fair value accounting and of the recent mixed attribute in nowadays financial reporting practices. The concluding remarks synthesize the obtained results and possible future developments of our analysis.

  1. Theoretical and experimental study of radon measurement with designing and calibration domestic canister with active charcoal

    International Nuclear Information System (INIS)

    Urosevic, V.; Nikezic, D.; Zekic, R.

    2005-01-01

    Radon concentration in air may change significantly large variation due to atmospheric variation. Measurement with active charcoal can be inaccurate because the variation in radon concentration. We made model to simulate radon measurements with active charcoal in order to optimize and improve integration characteristic. A numerical method and computer code based on the method of finite elements is developed for the case of variable radon concentration in air. This program simulates radon adsorption by the activated charcoal bed, enabling determination of sensitivity. The dependence of sensitivity on different parameters, such as temperature, thickness of the charcoal, etc. was studied using this program. Using results of theoretical investigation we designed and calibrated our canister with active charcoal for radon measurements. (author)

  2. Theoretical and experimental study of the dynamic behavior of a nonlinear Fabry-Perot interferrometer

    International Nuclear Information System (INIS)

    Bischofberger, T.; Shen, Y.R.

    1979-01-01

    We have studied theoretically and experimentally the dynamic behavior of a nonlinear Fabry-Perot interferrometer filled with a Kerr medium. The Fabry-Perot responses ranging from extremely transient to quasi-steady-state in various modes of operation are considered. The experimental results are in excellent agreement with theory. It is shown that the quasi-steady-state operation requires not only a medium response time much smaller than the cavity round-trip time, but also a characteristic time of the input intensity variation several hundred times larger than the cavity round-trip time. Even in the quasi-steady-state limit, optical switching is often featured by overshoot and ringing after switching. The switching speed is limited by the cavity buildup time

  3. Studies of Credit and Equity Markets with Concepts of Theoretical Physics

    CERN Document Server

    Münnix, Michael C

    2011-01-01

    Financial markets are becoming increasingly complex. The financial crisis of 2008 to 2009 has demonstrated that an improved understanding of the mechanisms embedded in the market is a key requirement for the estimation of financial risk. Recently, concepts of theoretical physics, in particular concepts of complex systems, have proven to be very useful in this regard. Michael C. Münnix analyses the statistical dependencies in financial markets and develops mathematical models using concepts and methods from physics. The author focuses on aspects that played a key role in the emergence of the recent financial crisis: estimation of credit risk, dynamics of statistical dependencies, and correlations on small time-scales. He visualizes the findings for various large-scale empirical studies of market data. The results give novel insights into the mechanisms of financial markets and allow conclusions on how to reduce financial risk significantly.

  4. Spectroscopic and theoretical studies on the aromaticity of pyrrol-2-yl-carbonyl conformers

    Science.gov (United States)

    Dubis, Alina T.; Wojtulewski, Sławomir; Filipkowski, Karol

    2013-06-01

    The aromaticity of s-cis and s-trans pyrrol-2-yl carbonyl conformers was studied by FT-IR, 1H NMR spectroscopy and DFT calculations at the B3LYP/6-311++G(d,p) level of theory. The Harmonic Oscillator Model of Aromaticity (HOMA) and Nucleus Independent Chemical Shift (NICS) indices were calculated to estimate π-electron delocalization in the pyrrole ring. The usefulness of infrared spectroscopy in the evaluation of the aromaticity of the homogeneous set of pyrroles is discussed. The influence of 2-substitution on different aspects of aromaticity and stability of the pyrrol-2-yl carbonyl conformers is also discussed. It is concluded that the substitution effect of the title pyrrole derivatives can be explained on the basis of theoretical and experimental measurements of π-electron delocalization, including IR data.

  5. A theoretical and spectroscopic study of co-amorphous naproxen and indomethacin

    DEFF Research Database (Denmark)

    Löbmann, Korbinian; Laitinen, Riikka; Grohganz, Holger

    2013-01-01

    . In this study, the co-amorphous drug mixture containing naproxen (NAP) and indomethacin (IND) was investigated using infrared spectroscopy (IR) and quantum mechanical calculations. The structures of both drugs were optimized as monomer, homodimer and heterodimer using density functional theory and used...... for the calculation of IR spectra. Conformational analysis confirmed that the optimized structures were suitable for the theoretical prediction of the spectra. Vibrational modes from the calculation could be matched with experimentally observed spectra for crystalline and amorphous NAP and IND, and it could be shown...... that NAP and IND exist as heterodimers in the co-amorphous mixture when quench cooled together from the melt in a 1:1 molar ratio....

  6. Experimental and theoretical studies on concrete structures with special-shaped shear walls

    Directory of Open Access Journals (Sweden)

    LIU Jianxin

    2014-06-01

    Full Text Available On the basis of concept design and staggered shear panels structure,this paper puts forward a new reinforced concrete high rise biuding structure with special-shaped shear walls and presents an experimental study of the seismic performance of the new special-shaped shear walls structure under low reversed cyclic loading using MTS electro hydraulic servo system.Compared with experimental results,a finite element analysis on this special-shaped shear wall structure,which considers the nonlinearity of concrete structure,is found suitable.It shows that the experimental results fairly confirms to the calculated values,which indicates that this new structure has advantages as good architecture function,big effective space,high overall lateral stiffness,fine ductility,advanced seismic behavior,etc..That is,the close r agreement between the theoretical and experimental results indicates the proposed shear wall structure has wide applications.

  7. Fragmentation dynamics of ionized neon trimer inside helium nanodroplets: a theoretical study.

    Science.gov (United States)

    Bonhommeau, David; Viel, Alexandra; Halberstadt, Nadine

    2004-06-22

    We report a theoretical study of the fragmentation dynamics of Ne(3) (+) inside helium nanodroplets, following vertical ionization of the neutral neon trimer. The motion of the neon atoms is treated classically, while transitions between the electronic states of the ionic cluster are treated quantum mechanically. A diatomics-in-molecules description of the potential energy surfaces is used, in a minimal basis set consisting of three effective p orbitals on each neon atom for the missing electron. The helium environment is modeled by a friction force acting on the neon atoms when their speed exceeds the Landau velocity. A reasonable range of values for the corresponding friction coefficient is obtained by comparison with existing experimental measurements. (c) 2004 American Institute of Physics.

  8. Theoretical study of molecular vibration and Application to linear triatomic molecules: case of OCS

    International Nuclear Information System (INIS)

    Andrianavalomahefa, A.

    2014-01-01

    Our aim is to give a theoretical approach to the calculation of vibrational energy levels of polyatomic molecules. By using matrix calculation, we have to solve an eigenvalue equation that gives normal vibration frequencies of the system. A basis change introduces normal coordinates of vibration, which diagonalize the Hamiltonian. The harmonic approximation gives a rough evaluation of parameters which describe the system. Then, we introduce nonlinear terms to take into account the anharmonicity of interatomic bounds. Morse oscillator gives good approximation for diatomic molecules. We consider cubic and quartic potential terms for polyatomic molecules. We treat the problem both in classical and quantum approach. The results thus obtained are applied to study longitudinal vibration of carbonyl sulfide. [fr

  9. Theoretical study on steric deconjugation of poly(3-hexylthiophene) through bromination

    Science.gov (United States)

    Ando, Hideo; Tanaka, Senku; Matsumoto, Kouichi; Nakao, Yoshihide

    2017-11-01

    In poly(3-hexylthiophene) (P3HT), it is suggested that bromination disturbs the π conjugation and reduces the carrier mobility. To investigate the deconjugation mechanism, we theoretically studied a key flexibility of the Br-P3HT backbone, namely inter-ring Ssbnd Csbnd Csbnd S dihedral torsion, in terms of potential energy curve, geometry-based aromaticity index, and decomposed energies of inter-monomer interaction. The linkage between bromination and the excitation energy was also investigated. We concluded that steric repulsion due to bulky bromo group can cause out-of-plane Ssbnd Csbnd Csbnd S torsion of Br-P3HT and consequent shortening of the conjugation length, not electronic substituent effect, leads to blue shift of the S0 →S1 excitation energy.

  10. Theoretical Study on Cyclopeptides as the Nanocarriers for Li+, Na+, K+ and F−, Cl−, Br−

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2015-01-01

    Full Text Available The interaction process between a series of cyclopeptide compounds cyclo(Glyn  (n=4,6,8 and monovalent ions (Li+, Na+, K+, F−, Cl−, and Br− was studied using theoretical calculation. The mechanism of combination between the cyclo(Glyn and ions was discussed through binding energy, Mulliken electron population, and hydrogen bond. It was found that for the same cyclopeptide the binding energy has the order of cyclo(Glyn–Li+ > cyclo(Glyn–Na+ > cyclo(Glyn–K+ and cyclo(Glyn–F− > cyclo(Glyn–Br− > cyclo(Glyn–Cl−. The binding energy manifests the stable complex of cyclo(Glyn and ions can be formed, and the different energy shows the potential use of cyclo(Glyn as nanocarriers for metal ions or the extractant for ions separation.

  11. Experimental and theoretical study on DPPH radical scavenging mechanism of some chalcone quinoline derivatives

    Science.gov (United States)

    Hamlaoui, Ikram; Bencheraiet, Reguia; Bensegueni, Rafik; Bencharif, Mustapha

    2018-03-01

    In this study, the antioxidant capacity of three chalcone derivatives was evaluated by DPPH free radical scavenging. Experimental data showed low antioxidant activity (IC50±SD) of these molecules in comparison with BHT. The mechanism of DPPH radical scavenging elucidated by means of density functional theory (DFT) calculations. The tested compounds and their corresponding radicals and anions were optimized using B3LYP functional with 6-31G (d,p) basis set in the gas phase. The C-PCM model was used to perform solvent medium calculations. On the basis of theoretical calculations, it was shown that HAT mechanism was predominant in the gas phase, whereas SET-PT and SPLET mechanisms were favored in the presence of the solvent. Moreover, the HOMO orbitals and spin density distribution was evaluated to predict the probable sites for free radical attack.

  12. A theoretical study of the dynamics of paramagnetic superrotors in external magnetic fields

    International Nuclear Information System (INIS)

    Floß, Johannes

    2015-01-01

    We present a detailed theoretical study of oxygen molecules in high rotational states (molecular superrotors) interacting with an external magnetic field. The system shows rich dynamics, ranging from a spin-selective splitting of the angular distribution over molecular alignment to an inversion of the rotational direction. We find that the observed magneto-rotational effects are due to a spin-mediated precession of the orbital angular momentum around the magnetic field. Analytical expressions for the precession frequency in the limits of weak and strong magnetic fields are derived and used to support the proposed mechanism. In addition, we provide the procedure for a numerical treatment of oxygen superrotors in an external magnetic field. (paper)

  13. Theoretical structural and vibrational study of 5-trifluoromethyluracil. A comparison with uracil

    Energy Technology Data Exchange (ETDEWEB)

    Rudyk, Roxana; Ramos, María E.; Checa, María A.; Brandán, Silvia A. [Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471,(4000), San Miguel de Tucumán, Tucum and #x00E1 (Argentina); Chamorro, Eduardo E. [Facultad de Ciencias Exactas, Universidad Andrés Bello, Avda. República 275, 8370146, Santiago (Chile)

    2014-10-06

    In the present work, a comparative study on the structural and vibrational properties of the 5-trifluoromethyluracil (TFMU) derivative with those corresponding to uracil in gas and aqueous solution phases was performed combining the available H{sup 1}-NMR, C{sup 13}-NMR, F{sup 19}-NMR and FTIR spectra with Density Functional Theory (DFT) calculations. Three stable conformers were theoretically determined in both media by using the hybrid B3LYP/6-31G* method. The solvent effects were simulated by means of the self-consistent reaction field (SCRF) method employing the integral equation formalism variant (IEFPCM). Complete assignments of the vibrational spectra in both phases were performed combining the internal coordinates analysis and the DFT calculations with the Scaled Quantum Mechanics Force Field (SQMFF) methodology. The atomic charges, bond orders, solvation energies, dipole moments, molecular electrostatic potentials and force constants parameters were calculated for the three conformers of TFMU in gas phase and aqueous solution.

  14. A theoretical quantum chemical study of alanine formation in interstellar medium

    Science.gov (United States)

    Shivani; Pandey, Parmanad; Misra, Alka; Tandon, Poonam

    2017-08-01

    The interstellar medium, the vast space between the stars, is a rich reservoir of molecular material ranging from simple diatomic molecules to more complex, astrobiologically important molecules such as amino acids, nucleobases, and other organic species. Radical-radical and radical-neutral interaction schemes are very important for the formation of comparatively complex molecules in low temperature chemistry. An attempt has been made to explore the possibility of formation of complex organic molecules in interstellar medium, through detected interstellar molecules like CH3CN and HCOOH. The gas phase reactions are theoretically studied using quantum chemical techniques. We used the density functional theory (DFT) at the B3LYP/6-311G( d, p) level. The reaction energies, potential barrier and optimized structures of all the geometries, involved in the reaction path, has been discussed. We report the potential energy surfaces for the reactions considered in this work.

  15. Fatigue study on the actuation performance of macro fiber composite (MFC): theoretical and experimental approach

    Science.gov (United States)

    Pandey, Akash; Arockiarajan, A.

    2017-03-01

    Macro fiber composite (MFC) is extensively used in vibration control and actuation applications due to its high flexibility and enhanced coupling coefficients. During these applications, MFCs are subjected to the continuous cyclic electrical loading, which may lead to the degradation in its actuation performance. In order to predict the life cycle of MFCs, an experimental setup has been devised and experiments are performed under cyclic loading condition. Efforts involved in the experiments are huge in terms of time and cost. Hence, an attempt has been made to develop a theoretical model to predict the fatigue behavior of MFCs. A nonlinear finite element method has been formulated based on Kirchhoff plate theory wherein the fatigue failure criterion based on strain energy is embedded. Simulated results based on the proposed model is compared with experimental observation and are in good agreement with each other. Variation in the life cycle of MFCs are also studied for different operating temperatures as well as structural/geometric configurations.

  16. Theoretical study and design of a splitting-recombining style homogenizer

    International Nuclear Information System (INIS)

    Park, Seong Hee; Ko, Do Kyeong; Kim, Hyun Su; Lim, Gwon; Cha, Byeong Hun; Kim, Cheol Jung

    2001-01-01

    For a flat-top laser beam with low low divergence, new scheme based on splitting, inverting, and recombining has been developed. The previous system developed in MicroLas for multimode Excimer lasers, however, cannot apply to a Gaussian beam. By adding functions of path compensation and adjustable beam overlapping, a new splitting-recombining style homogenizer can convert a Gaussian beam to a flat-top beam. Since this scheme is sensitive to accuracy of separation, ratio of beam splitting, and timing of recombination, input laser beam should be collimated to large size and a beam splitter with dielectric coating should be fabricated with high accuracy. We design and study theoretically the new splitting-recombining style homogenizer for a Gaussian laser beam, including the tolerance caused by misalignment or coating quality, the beam quality depending on the beam overlapping ratio, and the effects of longitudinal pulse profile and time delay between transmitted and re-combined beam.

  17. Chemistry of carbonization - I. A theoretical study of free radical formation from starting materials

    Energy Technology Data Exchange (ETDEWEB)

    Ruette, F.; Sierraalta, A.; Castells, V.; Laya, M. (Instituto Venezolano de Investigaciones Cientificas, Caracas (Venezuela). Laboratorio de Quimica Computacional)

    1993-01-01

    The effect of size, shape, and aromaticity in the formation of radicals from model polyaromatic hydrocarbons (PAH) was theoretically studied using the MINDO/3 method. The results were interpreted in terms of hydrogen transfer on carbonization and liquefaction processes of coal-related compounds. Additives that donate or withdraw electrons were modeled by calculating negatively or positively charged systems. The results show that the hydrogen donating properties of PAHs increase with the increase of their molecular weights. The formation of anionic [pi]-radicals is thermodynamically favoured, contrary to cationic [pi]-radicals. Negative charge favoured the formation of low molecular weight radicals, and therefore, the hydrogen transfer from light to heavy PAHs. Positive charges, in general, do not facilitate the hydrogen transfer. 42 refs., 2 figs., 4 tabs.

  18. Theoretical study of molecular structures, vibrational and NMR spectra on azobenzene derivatives

    Science.gov (United States)

    Karakaya, M.; Ucun, F.

    2014-02-01

    In this study, we have calculated the most stable tautomeric forms and their ground state conformers of 2,4-dihydroxyazobenzene and 2,4-dihydroxy-6-methyl-4'-nitroazobenzene molecules. Calculations show that the most preferential tautomeric forms of these molecules are azo form for 2,4-dihydroxyazobenzene and hydrazo form for 2,4-dihydroxy-6-methyl-4'-nitroazobenzene. Vibrational frequencies, 1H and 13C NMR shifts of ground state conformers of stable tautomeric forms of the molecules have been calculated by using density functional theory-B3LYP method with 6-311G(d,p) basis set. All assignments of theoretical frequencies have been performed by potential energy distribution analysis. Calculated spectral results are in a good agreement with the corresponding experimental data.

  19. Between Anthropology and History: some theoretical and methodological assumptions in the study of Terena reliogisities

    Directory of Open Access Journals (Sweden)

    Noêmia dos Santos Pereira Moura

    2017-12-01

    Full Text Available In this article we will outline the interdisciplinary theoretical-methodological path covered in the production resulting from the studies on Terena religiousness developed in recent years. For this, we will make some considerations about concepts and categories used throughout the text to support our arguments about the central hypothesis - the Terena, especially the religious leaders, appropriated and terenizaron the Christianity in the indigenous lands in Mato Grosso do Sul, the from the Taunay-Ipegue Indigenous Land. Among the several prominent approaches we selected as the central guideline the part of the abovementioned epigraph, which portrays the protagonism of these historical subjects Terena in reproducing as a society through non-indigenous religious and their Christian institutions, recruiting whites for their own continuity. Our trajectory, therefore, will be marked by the dialogues between Anthropology and History.

  20. Theoretical study of the porosity effects on the shock response of graphitic materials

    Directory of Open Access Journals (Sweden)

    Pineau Nicolas

    2015-01-01

    Full Text Available In this paper we present a theoretical study of the shock compression of porous graphite by means of combined Monte Carlo and molecular dynamics simulations using the LCBOPII potential. The results show that the Hugoniostat methods can be used with “pole” properties calculated from porous models to reproduce the experimental Hugoniot of pure graphite and diamond with good accuracy. The computed shock temperatures show a sharp increase for weak shocks which we analyze as the heating associated with the closure of the initial porosity. After this initial phase, the temperature increases with shock intensity at a rate comparable to monocrystalline graphite and diamond. These simulations data can be exploited in view to build a full equation of state for use in hydrodynamic simulations.