WorldWideScience

Sample records for semiconductor physics national

  1. Semiconductor physics

    CERN Document Server

    Böer, Karl W

    2018-01-01

    This handbook gives a complete survey of the important topics and results in semiconductor physics. It addresses every fundamental principle and most research topics and areas of application in the field of semiconductor physics. Comprehensive information is provided on crystalline bulk and low-dimensional as well as amporphous semiconductors, including optical, transport, and dynamic properties.

  2. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  3. Spin physics in semiconductors

    CERN Document Server

    Dyakonov, Mikhail I

    2008-01-01

    This book describes beautiful optical and transport phenomena related to the electron and nuclear spins in semiconductors with emphasis on a clear presentation of the physics involved. Recent results on quantum wells and quantum dots are reviewed. The book is intended for students and researchers in the fields of semiconductor physics and nanoelectronics.

  4. Physics of semiconductor lasers

    CERN Document Server

    Mroziewicz, B; Nakwaski, W

    2013-01-01

    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  5. Semiconductor detector physics

    International Nuclear Information System (INIS)

    Equer, B.

    1987-01-01

    Comprehension of semiconductor detectors follows comprehension of some elements of solid state physics. They are recalled here, limited to the necessary physical principles, that is to say the conductivity. P-n and MIS junctions are discussed in view of their use in detection. Material and structure (MOS, p-n, multilayer, ..) are also reviewed [fr

  6. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  7. The Physics of Semiconductors

    Science.gov (United States)

    Brennan, Kevin F.

    1999-02-01

    Modern fabrication techniques have made it possible to produce semiconductor devices whose dimensions are so small that quantum mechanical effects dominate their behavior. This book describes the key elements of quantum mechanics, statistical mechanics, and solid-state physics that are necessary in understanding these modern semiconductor devices. The author begins with a review of elementary quantum mechanics, and then describes more advanced topics, such as multiple quantum wells. He then disusses equilibrium and nonequilibrium statistical mechanics. Following this introduction, he provides a thorough treatment of solid-state physics, covering electron motion in periodic potentials, electron-phonon interaction, and recombination processes. The final four chapters deal exclusively with real devices, such as semiconductor lasers, photodiodes, flat panel displays, and MOSFETs. The book contains many homework exercises and is suitable as a textbook for electrical engineering, materials science, or physics students taking courses in solid-state device physics. It will also be a valuable reference for practicing engineers in optoelectronics and related areas.

  8. Semiconductor physics an introduction

    CERN Document Server

    Seeger, Karlheinz

    1999-01-01

    Semiconductor Physics - An Introduction - is suitable for the senior undergraduate or new graduate student majoring in electrical engineering or physics. It will also be useful to solid-state scientists and device engineers involved in semiconductor design and technology. The text provides a lucid account of charge transport, energy transport and optical processes, and a detailed description of many devices. It includes sections on superlattices and quantum well structures, the effects of deep-level impurities on transport, the quantum Hall effect and the calculation of the influence of a magnetic field on the carrier distribution function. This 6th edition has been revised and corrected, and new sections have been added to different chapters.

  9. Basic semiconductor physics

    CERN Document Server

    Hamaguchi, Chihiro

    2017-01-01

    This book presents a detailed description of basic semiconductor physics. The text covers a wide range of important phenomena in semiconductors, from the simple to the advanced. Four different methods of energy band calculations in the full band region are explained: local empirical pseudopotential, non-local pseudopotential, KP perturbation and tight-binding methods. The effective mass approximation and electron motion in a periodic potential, Boltzmann transport equation and deformation potentials used for analysis of transport properties are discussed. Further, the book examines experiments and theoretical analyses of cyclotron resonance in detail. Optical and transport properties, magneto-transport, two-dimensional electron gas transport (HEMT and MOSFET) and quantum transport are reviewed, while optical transition, electron-phonon interaction and electron mobility are also addressed. Energy and electronic structure of a quantum dot (artificial atom) are explained with the help of Slater determinants. The...

  10. Survey of semiconductor physics

    CERN Document Server

    Böer, Karl W

    1992-01-01

    Any book that covers a large variety of subjects and is written by one author lacks by necessity the depth provided by an expert in his or her own field of specialization. This book is no exception. It has been written with the encouragement of my students and colleagues, who felt that an extensive card file I had accumulated over the years of teaching solid state and semiconductor physics would be helpful to more than just a few of us. This file, updated from time to time, contained lecture notes and other entries that were useful in my research and permitted me to give to my students a broader spectrum of information than is available in typical textbooks. When assembling this material into a book, I divided the top­ ics into material dealing with the homogeneous semiconductor, the subject of the previously published Volume 1, and the inhomoge­ neous semiconductor, the subject of this Volume 2. In order to keep the book to a manageable size, sections of tutorial character which can be used as text for a g...

  11. Physical principles of semiconductor detectors

    International Nuclear Information System (INIS)

    Micek, S.L.

    1979-01-01

    The general properties of semiconductors with respect to the possibilities of their use as the ionization radiation detectors are discussed. Some chosen types of semiconductor junctions and their characteristics are briefly presented. There are also discussed the physical phenomena connected with the formation of barriers in various types of semiconductor counters. Finally, the basic properties of three main types of semiconductor detectors are given. (author)

  12. Spin physics in semiconductors

    CERN Document Server

    2017-01-01

    This book offers an extensive introduction to the extremely rich and intriguing field of spin-related phenomena in semiconductors. In this second edition, all chapters have been updated to include the latest experimental and theoretical research. Furthermore, it covers the entire field: bulk semiconductors, two-dimensional semiconductor structures, quantum dots, optical and electric effects, spin-related effects, electron-nuclei spin interactions, Spin Hall effect, spin torques, etc. Thanks to its self-contained style, the book is ideally suited for graduate students and researchers new to the field.

  13. Introductory semiconductor device physics

    CERN Document Server

    Parker, Greg

    2004-01-01

    ATOMS AND BONDINGThe Periodic TableIonic BondingCovalent BondingMetallic bondingvan der Waals BondingStart a DatabaseENERGY BANDS AND EFFECTIVE MASSSemiconductors, Insulators and MetalsSemiconductorsInsulatorsMetalsThe Concept of Effective MassCARRIER CONCENTRATIONS IN SEMICONDUCTORSDonors and AcceptorsFermi-LevelCarrier Concentration EquationsDonors and Acceptors Both PresentCONDUCTION IN SEMICONDUCTORSCarrier DriftCarrier MobilitySaturated Drift VelocityMobility Variation with TemperatureA Derivation of Ohm's LawDrift Current EquationsSemiconductor Band Diagrams with an Electric Field Presen

  14. Semiconductor radiation detectors. Device physics

    International Nuclear Information System (INIS)

    Lutz, G.

    2007-01-01

    Starting from basic principles, the author, whose own contributions to these developments have been significant, describes the rapidly growing field of modern semiconductor detectors used for energy and position measurement radiation. This development was stimulated by requirements in elementary particle physics where it has led to important scientific discoveries. It has now spread to many other fields of science and technology. The book is written in a didactic way and includes an introduction to semiconductor physics. The working principles of semiconductor radiation detectors are explained in an intuitive way, followed by formal quantitative analysis. Broad coverage is also given to electronic signal readout and to the subject of radiation damage. The book is the first to comprehensively cover the semiconductor radiation detectors currently in use. It is useful as a teaching guide and as a reference work for research and applications. (orig.)

  15. Semiconductor radiation detectors: device physics

    National Research Council Canada - National Science Library

    Lutz, Gerhard

    1999-01-01

    ..., including nuclear physics, elementary particle physics, optical and x-ray astronomy, medicine, and materials testing - and the number of applications is growing continually. Closely related, and initiated by the application of semiconductors, is the development of low-noise low-power integrated electronics for signal readout. The success of semicond...

  16. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2005-01-01

    Provides detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. This textbook emphasizes understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors and features an extensive collection of tables of material parameters, figures, and problems.

  17. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1995-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups; (i) classical semiconductor diode detectors and (ii) semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported. copyright 1995 American Institute of Physics

  18. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1992-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups: Classical semiconductor diode detectors and semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported

  19. Device Physics of Narrow Gap Semiconductors

    CERN Document Server

    Chu, Junhao

    2010-01-01

    Narrow gap semiconductors obey the general rules of semiconductor science, but often exhibit extreme features of these rules because of the same properties that produce their narrow gaps. Consequently these materials provide sensitive tests of theory, and the opportunity for the design of innovative devices. Narrow gap semiconductors are the most important materials for the preparation of advanced modern infrared systems. Device Physics of Narrow Gap Semiconductors offers descriptions of the materials science and device physics of these unique materials. Topics covered include impurities and defects, recombination mechanisms, surface and interface properties, and the properties of low dimensional systems for infrared applications. This book will help readers to understand not only the semiconductor physics and materials science, but also how they relate to advanced opto-electronic devices. The last chapter applies the understanding of device physics to photoconductive detectors, photovoltaic infrared detector...

  20. High pressure semiconductor physics I

    CERN Document Server

    Willardson, R K; Paul, William; Suski, Tadeusz

    1998-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise indeed that this tra...

  1. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2010-01-01

    This fourth edition of the well-established Fundamentals of Semiconductors serves to fill the gap between a general solid-state physics textbook and research articles by providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. The approach is physical and intuitive rather than formal and pedantic. Theories are presented to explain experimental results. This textbook has been written with both students and researchers in mind. Its emphasis is on understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors. The explanations are based on physical insights. Each chapter is enriched by an extensive collection of tables of material parameters, figures, and problems. Many of these problems "lead the student by the hand" to arrive at the results. The major changes made in the fourth edition include: an extensive appendix about the important and by now well-established deep center known as the DX center, additional problems...

  2. Physics with isotopically controlled semiconductors

    International Nuclear Information System (INIS)

    Haller, E.E.

    1994-08-01

    Control of the isotopic composition of semiconductors offers a wide range of new scientific opportunities. In this paper a number of recent results obtained with isotopically pure as well as deliberately mixed diamond and Ge bulk single crystals and Ge isotope superlattices will be reviewed. Isotopic composition affects several properties such as phonon energies, bandstructure and lattice constant in subtle but theoretically well understood ways. Large effects are observed for thermal conductivity, local vibrational modes of impurities and after neutron transmutation doping (NTD). Several experiments which could profit greatly from isotope control are proposed

  3. Physics of semiconductors in high magnetic fields

    CERN Document Server

    Miura, Noboru

    2008-01-01

    This book summarizes most of the fundamental physical phenomena which semiconductors and their modulated structures exhibit in high magnetic fields. Readers can learn not only the basic theoretical background but also the present state of the art from the most advanced data in this rapidly growing research area.

  4. Ultrafast Physics in Semiconductor Microstructures.

    Science.gov (United States)

    1988-02-19

    1588(1983). (27) Y. Silberger . P. W. Smith, D. JI Eienberger, D. A. B. Miller, A. C. Gossard, and W. Wiegmann. Opt. Lett. 9, 507(1984). S(28) B...and G. R. Fowles, in High Pressure Physic, and Chemistry , and Air Force Office of Scientific Research No. 86-003 1. edited by R. S. Bradley (Academic

  5. The Physics of Semiconductors An Introduction Including Devices and Nanophysics

    CERN Document Server

    Grundmann, Marius

    2006-01-01

    The Physics of Semiconductors provides material for a comprehensive upper-level-undergrauate and graduate course on the subject, guiding readers to the point where they can choose a special topic and begin supervised research. The textbook provides a balance between essential aspects of solid-state and semiconductor physics, on the one hand, and the principles of various semiconductor devices and their applications in electronic and photonic devices, on the other. It highlights many practical aspects of semiconductors such as alloys, strain, heterostructures, nanostructures, that are necessary in modern semiconductor research but typically omitted in textbooks. For the interested reader some additional advanced topics are included, such as Bragg mirrors, resonators, polarized and magnetic semiconductors are included. Also supplied are explicit formulas for many results, to support better understanding. The Physics of Semiconductors requires little or no prior knowledge of solid-state physics and evolved from ...

  6. 33rd International Conference on the Physics of Semiconductors

    International Nuclear Information System (INIS)

    2017-01-01

    Preface to the Proceedings of the 33rd International Conference on the Physics of Semiconductors, Beijing, 2016 Shaoyun Huang 1 , Yingjie Xing 1 , Yang Ji 2 , Dapeng Yu 3 , and Hongqi Xu 1 1 Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China 2 SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China 3 State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871, China From July 31 st to August 5 th , 2016, the 33rd International Conference on the Physics of Semiconductors (ICPS 2016) was held in Beijing, China, with a great success. The International Conference on the Physics of Semiconductors began in the 1950’s and is a premier biennial meeting for reporting all aspects of semiconductor physics including electronic, structural, optical, magnetic and transport properties. Reflecting the state of the art developments in semiconductor physics, ICPS 2016 served as an international forum for scholars, researchers, and specialists across the globe to discuss future research directions and technological advancements. The main topics of ICPS 2016 included: • Material growth, structural properties and characterization, phonons • Wide-bandgap semiconductors • Narrow-bandgap semiconductors • Carbon: nanotubes and graphene • 2D Materials beyond graphene • Organic semiconductors • Topological states of matter, topological Insulators and Weyl semimetals • Transport in heterostructures • Quantum Hall effects • Spintronics and spin phenomena • Electron devices and applications • Optical properties, optoelectronics, solar cells • Quantum optics, nanophotonics • Quantum information • Other topics in semiconductor physics and devices • Special topic: Majorana fermions in solid state (paper)

  7. Introduction to the Physics of Diluted Magnetic Semiconductors

    CERN Document Server

    Gaj, Jan A

    2010-01-01

    The book deals with diluted magnetic semiconductors, a class of materials important to the emerging field of spintronics. In these materials semiconducting properties, both transport and optical, are influenced by the presence of magnetic ions. It concentrates on basic physical mechanisms (e.g. carrier-ion and ion-ion interactions) and resulting phenomena (e.g. magnetic polaron formation and spin relaxation). Introduction to the Physics of Diluted Magnetic Semiconductors is addressed to graduate-level and doctoral students and young researchers entering the field. The authors have been actively involved in the creation of this branch of semiconductor physics.

  8. National Physics Conference

    International Nuclear Information System (INIS)

    Oancea, Margareta; Sandu, Doina; Calboreanu, Rodica

    2000-01-01

    The National Physics Conference organized annually by the Romanian Physical Society has been held in Constanta, Romania on September 21-23, 2000. It covered the following 12 sections: - 1. Astrophysics and High Energy (9 reports); - 2. Atomic and Molecular Physics (20 reports); - 3. Nuclear Physics (18 reports); - 4. Technical and Engineering Physics (34 reports); - 5. Condensed Matter Physics (67 reports); - 6. Optics and Quantum Electronics (12 reports); - 7. Plasma Physics (27 reports); - 8. Biophysics (30 reports); - 9. Physics for Energy (17 reports); - 10. Mathematical and Computational Physics (20 reports); -11. Physics and Education (8 reports); - 12. Earth and Environmental Physics (16 reports). The proceedings contains mainly short communications

  9. Physical limitations of semiconductor devices defects, reliability and esd protection

    CERN Document Server

    Vashchenko, V A

    2008-01-01

    Provides an important link between the theoretical knowledge in the field of non-linier physics and practical application problems in microelectronics. This title focuses on power semiconductor devices and self-triggering pulsed power devices for ESD protection clamps.

  10. 32nd International Conference on the Physics of Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chelikowsky, James [Univ. of Texas, Austin, TX (United States)

    2016-10-17

    The International Conference on the Physics of Semiconductors (ICPS) continues a series of biennial conferences that began in the 1950's. ICPS is the premier meeting for reporting all aspects of semiconductor physics including electronic, structural, optical, magnetic and transport properties with an emphasis on new materials and their applications. The meeting will reflect the state of art in the semiconductor physics field and will serve as a forum where scholars, researchers, and specialists can interact to discuss future research directions and technological advancements. The conference typically draws 1,000 international physicists, scientists, and students. This is one of the largest science meetings on semiconductors and related materials to be held in the United States.

  11. The physics of semiconductors an introduction including nanophysics and applications

    CERN Document Server

    Grundmann, Marius

    2016-01-01

    The 3rd edition of this successful textbook contains ample material for a comprehensive upper-level undergraduate or beginning graduate course, guiding readers to the point where they can choose a special topic and begin supervised research. The textbook provides a balance between essential aspects of solid-state and semiconductor physics, on the one hand, and the principles of various semiconductor devices and their applications in electronic and photonic devices, on the other. It highlights many practical aspects of semiconductors such as alloys, strain, heterostructures, nanostructures, that are necessary in modern semiconductor research but typically omitted in textbooks. Coverage also includes additional advanced topics, such as Bragg mirrors, resonators, polarized and magnetic semiconductors, nanowires, quantum dots, multi-junction solar cells, thin film transistors, carbon-based nanostructures and transparent conductive oxides. The text derives explicit formulas for many results to support better under...

  12. Quantum Dot Semiconductor Optical Amplifiers - Physics and Applications

    DEFF Research Database (Denmark)

    Berg, Tommy Winther

    2004-01-01

    This thesis describes the physics and applications of quantum dot semiconductor optical amplifiers based on numerical simulations. These devices possess a number of unique properties compared with other types of semiconductor amplifiers, which should allow enhanced performance of semiconductor...... respects is comparable to those of fiber amplifiers. The possibility of inverting the optically active states to a large degree is essential in order to achieve this performance. Optical signal processing through cross gain modulation and four wave mixing is modeled and described. For both approaches...... and QW devices and to experiments on quantum dot amplifiers. These comparisons outline the qualitative differences between the different types of amplifiers. In all cases focus is put on the physical processes responsible the differences....

  13. Problems and progress in radiation physics of semiconductors

    International Nuclear Information System (INIS)

    Vinetskij, V.L.

    1982-01-01

    A survey of the current status of radiation physics of semiconductors comprises the analysis of some new problems and poses the statement of concern. The essential difference between the probability of interstitial-vacancy pair occurrence W(T) in elastic collisions and the generally accepted step distribution with a typical ''threshold'' energy Tsub(d) is indicated. The role of diffusion and reaction evolution of primary defects leading to specific properties of the cluster formation process is shown. Special features of defect formation in spatially inhomogeneous semiconductors, in particular for elastic stresses present, are described. Among most important advances in the radiation physics of semiconductors there are the discovery of non-activation motion of the ''extra'' atom in silicon, the observation of a low activation energy value for the vacancy diffusion, the understanding of subthreshold mechanism of defect formation and radiation-induced diffusion, the effects of laser annealing of defects and oriented crystallization

  14. Assessing Conceptual Knowledge for the Physics of Semiconductors

    Science.gov (United States)

    Ene, Emanuela

    2013-01-01

    Following the trend in science and engineering education generated by the visible impact created by the Force Concept Inventory (FCI), the investigator developed a Physics of Semiconductors Concept Inventory (PSCI). PSCI fills the need of standardized concept tests for undergraduate education in photonics and electrical engineering. The structure…

  15. Semiconductor

    International Nuclear Information System (INIS)

    2000-01-01

    This book deals with process and measurement of semiconductor. It contains 20 chapters, which goes as follows; semiconductor industry, introduction of semiconductor manufacturing, yield of semiconductor process, materials, crystal growth and a wafer forming, PN, control pollution, oxidation, photomasking photoresist chemistry, photomasking technologies, diffusion and ion injection, chemical vapor deposition, metallization, wafer test and way of evaluation, semiconductor elements, integrated circuit and semiconductor circuit technology.

  16. Applying Physics: Opportunities in Semiconductor Technology Companies

    Science.gov (United States)

    Redinbo, Greg

    2011-03-01

    While many physicists practice in university settings, physics skills can also be applied outside the traditional academic track. ~Identifying these opportunities requires a clear understanding of how your physics training can be used in an industrial setting, understanding what challenges technology companies face, and identifying how your problem solving skills can be broadly applied in technology companies. ~In this talk I will highlight the common features of such companies, discuss what specific skills are useful for an industrial physicist, and explain roles (possibly unfamiliar) that may be available to you.

  17. Physics of low-dimensional semiconductor structures

    CERN Document Server

    March, Norman; Tosi, Mario

    1993-01-01

    Presenting the latest advances in artificial structures, this volume discusses in-depth the structure and electron transport mechanisms of quantum wells, superlattices, quantum wires, and quantum dots It will serve as an invaluable reference and review for researchers and graduate students in solid-state physics, materials science, and electrical and electronic engineering

  18. Physical models of semiconductor quantum devices

    CERN Document Server

    Fu, Ying

    2013-01-01

    The science and technology relating to nanostructures continues to receive significant attention for its applications to various fields including microelectronics, nanophotonics, and biotechnology. This book describes the basic quantum mechanical principles underlining this fast developing field. From the fundamental principles of quantum mechanics to nanomaterial properties, from device physics to research and development of new systems, this title is aimed at undergraduates, graduates, postgraduates, and researchers.

  19. Canberra semiconductor, an industrial partner for physics research

    International Nuclear Information System (INIS)

    Verplancke, J.; Burger, P.; Schoenmaekers, W.

    1990-01-01

    Canberra semiconductor produces germanium and silicon solid state detectors for nuclear radiation. Its business domain covers the production of standard detectors on an industrial basis, for industrial and applied physics applications, as well as the development of special detectors and electronics, tailored to the needs of a particular application, in science and research. There exists an important and beneficial interaction between these two activities. (orig.)

  20. 4. Ukrainian Scientific Conference on Semiconductor Physics (USCPS - 4). Part 2. Abstracts

    International Nuclear Information System (INIS)

    Machulin, V.F.

    2009-01-01

    The materials reflect the content of the conference papers, in which the novel results, state and perspectives of research in the field of semiconductor physics, electronic or phonon phenomena on the surface and in bulk semiconductors, nano- and quantum dimensional structures, physics of modern solid state devices, semiconductor materials and technologies are presented.

  1. Optically pumped semiconductor lasers for atomic and molecular physics

    Science.gov (United States)

    Burd, S.; Leibfried, D.; Wilson, A. C.; Wineland, D. J.

    2015-03-01

    Experiments in atomic, molecular and optical (AMO) physics rely on lasers at many different wavelengths and with varying requirements on spectral linewidth, power and intensity stability. Optically pumped semiconductor lasers (OPSLs), when combined with nonlinear frequency conversion, can potentially replace many of the laser systems currently in use. We are developing a source for laser cooling and spectroscopy of Mg+ ions at 280 nm, based on a frequency quadrupled OPSL with the gain chip fabricated at the ORC at Tampere Univ. of Technology, Finland. This OPSL system could serve as a prototype for many other sources used in atomic and molecular physics.

  2. Fast physical random bit generation with chaotic semiconductor lasers

    Science.gov (United States)

    Uchida, Atsushi; Amano, Kazuya; Inoue, Masaki; Hirano, Kunihito; Naito, Sunao; Someya, Hiroyuki; Oowada, Isao; Kurashige, Takayuki; Shiki, Masaru; Yoshimori, Shigeru; Yoshimura, Kazuyuki; Davis, Peter

    2008-12-01

    Random number generators in digital information systems make use of physical entropy sources such as electronic and photonic noise to add unpredictability to deterministically generated pseudo-random sequences. However, there is a large gap between the generation rates achieved with existing physical sources and the high data rates of many computation and communication systems; this is a fundamental weakness of these systems. Here we show that good quality random bit sequences can be generated at very fast bit rates using physical chaos in semiconductor lasers. Streams of bits that pass standard statistical tests for randomness have been generated at rates of up to 1.7 Gbps by sampling the fluctuating optical output of two chaotic lasers. This rate is an order of magnitude faster than that of previously reported devices for physical random bit generators with verified randomness. This means that the performance of random number generators can be greatly improved by using chaotic laser devices as physical entropy sources.

  3. NATO Advanced Study Institute on Physics of Submicron Semiconductor Devices

    CERN Document Server

    Ferry, David; Jacoboni, C

    1988-01-01

    The papers contained in the volume represent lectures delivered as a 1983 NATO ASI, held at Urbino, Italy. The lecture series was designed to identify the key submicron and ultrasubmicron device physics, transport, materials and contact issues. Nonequilibrium transport, quantum transport, interfacial and size constraints issues were also highlighted. The ASI was supported by NATO and the European Research Office. H. L. Grubin D. K. Ferry C. Jacoboni v CONTENTS MODELLING OF SUB-MICRON DEVICES.................. .......... 1 E. Constant BOLTZMANN TRANSPORT EQUATION... ... ...... .................... 33 K. Hess TRANSPORT AND MATERIAL CONSIDERATIONS FOR SUBMICRON DEVICES. . .. . . . . .. . . . .. . .. . .... ... .. . . . .. . . . .. . . . . . . . . . . 45 H. L. Grubin EPITAXIAL GROWTH FOR SUB MICRON STRUCTURES.................. 179 C. E. C. Wood INSULATOR/SEMICONDUCTOR INTERFACES.......................... 195 C. W. Wilms en THEORY OF THE ELECTRONIC STRUCTURE OF SEMICONDUCTOR SURFACES AND INTERFACES...................

  4. Proceedings of the 9. National Meeting on Condensed Matter Physics

    International Nuclear Information System (INIS)

    1986-01-01

    The 9. National Meeting on Condensed Matter Physics presents works developed in the following fields: amorphous materials, atomic and molecular physics, biophysics, crystallography, defects, growth and critical phenomena, instrumentation, liquid crystals, magnetism, matter science/mechanical properties, metals and alloys, optic, magnetic resonance and semiconductors. (M.C.K.) [pt

  5. Proceedings of the 12. National Meeting on Condensed Matter Physics

    International Nuclear Information System (INIS)

    1989-01-01

    The XII National Meeting on Condensed Matter Physics presented works in the areas: atomic and molecular physics; biophysics; crystallography; defects growth and characterization of crystals; instrumentation; liquid crystals; magnetism; science of materials, metals and alloys; magnetic resonance; semiconductors; superconductivity and; surfaces and thin films. (M.C.K.) [pt

  6. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Varo, Pilar [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Bertoluzzi, Luca [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Bisquert, Juan, E-mail: bisquert@uji.es [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Alexe, Marin [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Coll, Mariona [Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193, Bellaterra, Catalonia (Spain); Huang, Jinsong [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States); Jimenez-Tejada, Juan Antonio [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Kirchartz, Thomas [IEK5-Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany); Faculty of Engineering and CENIDE, University of Duisburg–Essen, Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nechache, Riad; Rosei, Federico [INRS—Center Énergie, Matériaux et Télécommunications, Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2 (Canada); Yuan, Yongbo [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States)

    2016-10-07

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  7. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    International Nuclear Information System (INIS)

    Lopez-Varo, Pilar; Bertoluzzi, Luca; Bisquert, Juan; Alexe, Marin; Coll, Mariona; Huang, Jinsong; Jimenez-Tejada, Juan Antonio; Kirchartz, Thomas; Nechache, Riad; Rosei, Federico; Yuan, Yongbo

    2016-01-01

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  8. Physically-based modelling of polycrystalline semiconductor devices

    International Nuclear Information System (INIS)

    Lee, S.

    2000-01-01

    Thin-film technology using polycrystalline semiconductors has been widely applied to active-matrix-addressed liquid crystal displays (AMLCDs) where thin-film transistors act as digital pixel switches. Research and development is in progress to integrate the driver circuits around the peripheral of the display, resulting in significant cost reduction of connections between rows and columns and the peripheral circuitry. For this latter application, where for instance it is important to control the greyscale voltage level delivered to the pixel, an understanding of device behaviour is required so that models can be developed for analogue circuit simulation. For this purpose, various analytical models have been developed based on that of Seto who considered the effect of monoenergetic trap states and grain boundaries in polycrystalline materials but not the contribution of the grains to the electrical properties. The principal aim of this thesis is to describe the use of a numerical device simulator (ATLAS) as a tool to investigate the physics of the trapping process involved in the device operation, which additionally takes into account the effect of multienergetic trapping levels and the contribution of the grain into the modelling. A study of the conventional analytical models is presented, and an alternative approach is introduced which takes into account the grain regions to enhance the accuracy of the analytical modelling. A physically-based discrete-grain-boundary model and characterisation method are introduced to study the effects of the multienergetic trap states on the electrical characteristics of poly-TFTs using CdSe devices as the experimental example, and the electrical parameters such as the density distribution of the trapping states are extracted. The results show excellent agreement between the simulation and experimental data. The limitations of this proposed physical model are also studied and discussed. (author)

  9. Physics of grain boundaries in polycrystalline photovoltaic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yanfa, E-mail: yanfa.yan@utoledo.edu; Yin, Wan-Jian; Wu, Yelong; Shi, Tingting; Paudel, Naba R. [Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Ohio 43606 (United States); Li, Chen [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Poplawsky, Jonathan [The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wang, Zhiwei [Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Ohio 43606 (United States); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Moseley, John; Guthrey, Harvey; Moutinho, Helio; Al-Jassim, Mowafak M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Pennycook, Stephen J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2015-03-21

    Thin-film solar cells based on polycrystalline Cu(In,Ga)Se{sub 2} (CIGS) and CdTe photovoltaic semiconductors have reached remarkable laboratory efficiencies. It is surprising that these thin-film polycrystalline solar cells can reach such high efficiencies despite containing a high density of grain boundaries (GBs), which would seem likely to be nonradiative recombination centers for photo-generated carriers. In this paper, we review our atomistic theoretical understanding of the physics of grain boundaries in CIGS and CdTe absorbers. We show that intrinsic GBs with dislocation cores exhibit deep gap states in both CIGS and CdTe. However, in each solar cell device, the GBs can be chemically modified to improve their photovoltaic properties. In CIGS cells, GBs are found to be Cu-rich and contain O impurities. Density-functional theory calculations reveal that such chemical changes within GBs can remove most of the unwanted gap states. In CdTe cells, GBs are found to contain a high concentration of Cl atoms. Cl atoms donate electrons, creating n-type GBs between p-type CdTe grains, forming local p-n-p junctions along GBs. This leads to enhanced current collections. Therefore, chemical modification of GBs allows for high efficiency polycrystalline CIGS and CdTe thin-film solar cells.

  10. The practice of problem-based investigative teaching reform in semiconductor physics course

    Science.gov (United States)

    Chen, Aiping; Wu, Gaojian; Gu, Dawei; Jiang, Hongying; Wang, Lei

    2017-08-01

    Semiconductor physics is an important basic course for the students of the majors of applied physics, optoelectronics, and microelectronics. The authors have been carrying out investigative-teaching reform in semiconductor physics teaching. Firstly, the teaching content was re-structured based on scientific problems. Secondly, the students were placed in groups to discuss different scientific problems and to present a few short science-reports. Thirdly, micro-lesson videos were produced for the students to study and analyze before or after class. With comparative analysis, we find out that the semiconductor-physics curriculum content was greatly enriched. In addition, the students' learning motivation and scientific thinking ability increased, and their innovation ability was improved. Overall, the teaching quality of the semiconductor physics course could be significantly improved.

  11. Controlling the speed of light in semiconductor waveguides: Physics and applications

    DEFF Research Database (Denmark)

    Mørk, Jesper; Xue, Weiqi; Chen, Yaohui

    2009-01-01

    We review the physics of slow and fast light effects in semiconductor optical waveguides. Recent experimental and theoretical results on enhancing the phase shift using optical filtering are presented and applications in microwave photonics are discussed.......We review the physics of slow and fast light effects in semiconductor optical waveguides. Recent experimental and theoretical results on enhancing the phase shift using optical filtering are presented and applications in microwave photonics are discussed....

  12. National Nuclear Physics Summer School

    CERN Document Server

    2016-01-01

    The 2016 National Nuclear Physics Summer School (NNPSS) will be held from Monday July 18 through Friday July 29, 2016, at the Massachusetts Institute of Technology (MIT). The summer school is open to graduate students and postdocs within a few years of their PhD (on either side) with a strong interest in experimental and theoretical nuclear physics. The program will include the following speakers: Accelerators and Detectors - Elke-Caroline Aschenauer, Brookhaven National Laboratory Data Analysis - Michael Williams, MIT Double Beta Decay - Lindley Winslow, MIT Electron-Ion Collider - Abhay Deshpande, Stony Brook University Fundamental Symmetries - Vincenzo Cirigliano, Los Alamos National Laboratory Hadronic Spectroscopy - Matthew Shepherd, Indiana University Hadronic Structure - Jianwei Qiu, Brookhaven National Laboratory Hot Dense Nuclear Matter 1 - Jamie Nagle, Colorado University Hot Dense Nuclear Matter 2 - Wilke van der Schee, MIT Lattice QCD - Sinead Ryan, Trinity College Dublin Neutrino Theory - Cecil...

  13. Plenary lectures of the divisions semiconductor physics, thin films, dynamics and statistical physics, magnetism, metal physics, surface physics, low temperature physics

    International Nuclear Information System (INIS)

    Roessler, U.

    1992-01-01

    This volume contains a selection of plenary and invited lectures of the Solid State Division spring meeting of the DPG (Deutsche Physikalische Gesellschaft) 1992 in Regensburg. The constribution come mainly from five fields of the physics of condensed matter: doped fullerenes and high Tc superconductors, surfaces, time-resolved on nonlinear optics, polymer melts, and low-dimensional semiconductor systems. (orig.)

  14. 75 FR 879 - National Semiconductor Corporation Arlington Manufacturing Site Including On-Site Leased Workers...

    Science.gov (United States)

    2010-01-06

    ... engaged in activities related to the production of integrated circuits. The company reports that on-site... Corporation Arlington Manufacturing Site Including On-Site Leased Workers From GCA, CMPA (Silverleaf), Custom..., applicable to workers of National Semiconductor Corporation, Arlington Manufacturing Site, including on-site...

  15. National Physics Conference. Paper Abstracts

    International Nuclear Information System (INIS)

    Marinela Dumitriu, Editorial Coordination.

    1995-01-01

    This book contains the abstracts of the proceedings of the annual Romanian Physics Conference organized by Romanian Physics Society. The conference was held on November 30 to December 2, 1995 in the city of Baia Mare. It was organized in the following nine sections: 1 - Astrophysics, Particle Physics, Nuclear Physics, Molecular and Atomic Physics; 2 - Plasma Physics; 3 - Biophysics; 4 - Technical Physics; 5 - Theoretical Physics; 6 -The Physics of Energy; 7 - The Physics of Environment 8 - Solid State Physics; 9 - Optical and Quantum Electronics. The full texts can be obtained on request from the Romanian Physical Society or directly from authors

  16. Conductors, semiconductors, superconductors an introduction to solid state physics

    CERN Document Server

    Huebener, Rudolf P

    2016-01-01

    This undergraduate textbook provides an introduction to the fundamentals of solid state physics, including a description of the key people in the field and the historic context. The book concentrates on the electric and magnetic properties of materials. It is written for students up to the bachelor level in the fields of physics, materials science, and electric engineering. Because of its vivid explanations and its didactic approach, it can also serve as a motivating pre-stage and supporting companion in the study of the established and more detailed textbooks of solid state physics. The textbook is suitable for a quick repetition prior to examinations. This second edition is extended considerably by detailed mathematical treatments in many chapters, as well as extensive coverage of magnetic impurities.

  17. Proceedings of the 14. National Meeting on Condensed Matter Physics

    International Nuclear Information System (INIS)

    1991-01-01

    Studies on atomic and molecular physics, crystallography, statistical physics and critical phenomena, instrumentation, liquid crystals, magnetism, metals and alloys, magnetic resonance, superconductivity and semi-conductors are presented. (M.C.K.)

  18. National Physics Conference, CNF 2001, Iasi. Abstracts

    International Nuclear Information System (INIS)

    Rusu, George; Caltun, Ovidiu

    2001-01-01

    The National Physics Conference, organized by Romanian Physics Society, was held on October 18-20, 2001 in Iasi, Romania. There were 8 sections as follows: Theoretical and Computational Physics; Magnetism and Magnetic Materials; Condensed Matter Physics and Technical Physics; Plasma Physics; Atomic and Nuclear Physics; Optics and Quantum Electronics; Physics and Education; Biophysics, Earth and Environment Physics. The papers accepted as being of INIS interest were mainly in the fields of Plasma Fusion, High Energy and Nuclear Physics, Instrumentation Related to Nuclear Science, Radiation Protection, Isotope Production and Materials Science

  19. The national conference on theoretical physics. Abstracts

    International Nuclear Information System (INIS)

    Grecu, Dan; Visinescu, Anca;

    2002-01-01

    The first edition of the National Conference on Theoretical Physics held on September 13-16, 2002 in Bucharest, Romania was organized by the Theoretical Physics Department of the Horia Hulubei National Institute of Physics and Nuclear Engineering in cooperation with the Physics Department of the University of Bucharest . There were presented 51 communications grouped in five sections as follows: 1. Quantum Field Theory, Elementary Particles, Gravitation; 2. Atomic, Molecular and Nuclear Theory, Astrophysics; 3. Condensed Matter Theory, Statistical Physics; 4. Computational and Mathematical Physics, Nonlinear Phenomena; 5. Interdisciplinary Fields

  20. Study of The Physical Properties of Some Semiconductor Materials

    International Nuclear Information System (INIS)

    Abdel-Wahab, A.A.

    2012-01-01

    The present paper reports the effect of replacement of selenium by indium on the optical gap and some other physical parameters of new quaternary chalcogenide InxSn 20 Se (60-x) Bi 20 (x = 0, 0.1, 0.2 and 0.3 at. %) thin films. Thin films with thickness 100 nm of InxSn 20 Se (60-x) Bi 20 were prepared by thermal evaporation of the bulk samples. Increasing indium content is found to affect the average heat of atomization, the average coordination number, the number of constraints and the cohesive energy of the InxSn 20 Se (60-x) Bi 20 alloys. Optical absorption measurements showed that the fundamental absorption edge is a function of composition. The optical absorption is due to allowed non-direct transition and the energy gap decreases with the increase of indium content. The chemical bond approach has been applied successfully to interpret the decrease of the optical gap with increasing indium content. The prepared films were irradiated by gamma rays at doses up to 15 Mrad. It was found that the compositions were almost stable against gamma radiation.

  1. Physical properties and analytical models of band-to-band tunneling in low-bandgap semiconductors

    International Nuclear Information System (INIS)

    Shih, Chun-Hsing; Dang Chien, Nguyen

    2014-01-01

    Low-bandgap semiconductors, such as InAs and InSb, are widely considered to be ideal for use in tunnel field-effect transistors to ensure sufficient on-current boosting at low voltages. This work elucidates the physical and mathematical considerations of applying conventional band-to-band tunneling models in low-bandgap semiconductors, and presents a new analytical alternative for practical use. The high-bandgap tunneling generates most at maximum field region with shortest tunnel path, whereas the low-bandgap generations occur dispersedly because of narrow tunnel barrier. The local electrical field associated with tunneling-electron numbers dominates in low-bandgap materials. This work proposes decoupled electric-field terms in the pre-exponential factor and exponential function of generation-rate expressions. Without fitting, the analytical results and approximated forms exhibit great agreements with the sophisticated forms both in high- and low-bandgap semiconductors. Neither nonlocal nor local field is appropriate to be used in numerical simulations for predicting the tunneling generations in a variety of low- and high-bandgap semiconductors

  2. A national assessment of physical activity on US national forests

    Science.gov (United States)

    Jeffrey D. Kline; Randall S. Rosenberger; Eric M. White

    2011-01-01

    In an era of declining timber harvests on federal lands, the US Forest Service has sought to better describe the public benefits associated with the nation's continued investment in managing the national forests. We considered how national forests contribute to public health by providing significant outdoor recreation opportunities. Physical inactivity has become...

  3. 16th Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics

    Science.gov (United States)

    Suris, Robert A.; Vorobjev, Leonid E.; Firsov, Dmitry A.

    2015-01-01

    The 16th Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics was held on November 24 - 28 at St. Petersburg Polytechnic University. The program of the Conference included semiconductor technology, heterostructures with quantum wells and quantum dots, opto- and nanoelectronic devices, and new materials. A large number of participants with about 200 attendees from many regions of Russia provided a perfect platform for the valuable discussions between students and experienced scientists. The Conference included two invited talks given by a corresponding member of RAS P.S. Kopyev ("Nitrides: the 4th Nobel Prize on semiconductor heterostructures") and Dr. A.V. Ivanchik ("XXI century is the era of precision cosmology"). Students, graduate and postgraduate students presented their results on plenary and poster sessions. The total number of accepted papers published in Russian (the official conference language) was 92. Here we publish 18 of them in English. Like previous years, the participants were involved in the competition for the best report. Certificates and cash prizes were awarded to a number of participants for the presentations selected by the Program Committee. Two special E.F. Gross Prizes were given for the best presentations in semiconductor optics. Works with potential applications were recommended for participation in the following competition for support from the Russian Foundation for Assistance to Small Innovative Enterprises in Science and Technology. The Conference was supported by the Russian Foundation for Basic Research, the "Dynasty" foundation and the innovation company "ATC - Semiconductor Devices", St. Petersburg. The official Conference website is http://www.semicond.spbstu.ru/conf2014-eng.html

  4. Current problems in semiconductor detectors for high energy physics after particle irradiations

    International Nuclear Information System (INIS)

    Lazanu, Ionel

    2002-01-01

    The use of semiconductor materials as detectors in high radiation environments, as expected in future high energy accelerators or in space missions, poses severe problems in long-time operations, due to changes in the properties of the material, and consequently in the performances of detectors. This talk presents the major theoretical areas of current problems, reviews the works in this field and the stage of their understanding, including author's contributions The mechanisms of interaction of the projectile with the semiconductor, the production of primary defects, the physical quantities and the equations able to characterise and describe the radiation effects, and the equations of kinetics of defects are considered. Correlation between microscopic damage and detector performances and the possible ways to optimise the radiation hardness of materials are discussed. (author)

  5. Point Defects in Two-Dimensional Layered Semiconductors: Physics and Its Applications

    Science.gov (United States)

    Suh, Joonki

    Recent advances in material science and semiconductor processing have been achieved largely based on in-depth understanding, efficient management and advanced application of point defects in host semiconductors, thus finding the relevant techniques such as doping and defect engineering as a traditional scientific and technological solution. Meanwhile, two- dimensional (2D) layered semiconductors currently draw tremendous attentions due to industrial needs and their rich physics at the nanoscale; as we approach the end of critical device dimensions in silicon-based technology, ultra-thin semiconductors have the potential as next- generation channel materials, and new physics also emerges at such reduced dimensions where confinement of electrons, phonons, and other quasi-particles is significant. It is therefore rewarding and interesting to understand and redefine the impact of lattice defects by investigating their interactions with energy/charge carriers of the host matter. Potentially, the established understanding will provide unprecedented opportunities for realizing new functionalities and enhancing the performance of energy harvesting and optoelectronic devices. In this thesis, multiple novel 2D layered semiconductors, such as bismuth and transition- metal chalcogenides, are explored. Following an introduction of conventional effects induced by point defects in semiconductors, the related physics of electronically active amphoteric defects is revisited in greater details. This can elucidate the complication of a two-dimensional electron gas coexisting with the topological states on the surface of bismuth chalcogenides, recently suggested as topological insulators. Therefore, native point defects are still one of the keys to understand and exploit topological insulators. In addition to from a fundamental science point of view, the effects of point defects on the integrated thermal-electrical transport, as well as the entropy-transporting process in

  6. Physics and application of persistent spin helix state in semiconductor heterostructures

    Science.gov (United States)

    Kohda, Makoto; Salis, Gian

    2017-07-01

    In order to utilize the spin degree of freedom in semiconductors, control of spin states and transfer of the spin information are fundamental requirements for future spintronic devices and quantum computing. Spin orbit (SO) interaction generates an effective magnetic field for moving electrons and enables spin generation, spin manipulation and spin detection without using external magnetic field and magnetic materials. However, spin relaxation also takes place due to a momentum dependent SO-induced effective magnetic field. As a result, SO interaction is considered to be a double-edged sword facilitating spin control but preventing spin transport over long distances. The persistent spin helix (PSH) state solves this problem since uniaxial alignment of the SO field with SU(2) symmetry enables the suppression of spin relaxation while spin precession can still be controlled. Consequently, understanding the PSH becomes an important step towards future spintronic technologies for classical and quantum applications. Here, we review recent progress of PSH in semiconductor heterostructures and its device application. Fundamental physics of SO interaction and the conditions of a PSH state in semiconductor heterostructures are discussed. We introduce experimental techniques to observe a PSH and explain both optical and electrical measurements for detecting a long spin relaxation time and the formation of a helical spin texture. After emphasizing the bulk Dresselhaus SO coefficient γ, the application of PSH states for spin transistors and logic circuits are discussed.

  7. CDZNTE ROOM-TEMPERATURE SEMICONDUCTOR GAMMA-RAY DETECTOR FOR NATIONAL-SECURITY APPLICATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    CAMARDA,G.S.; BOLOTNIKOV, A.E.; CUI, Y.; HOSSAIN, A.; KOHMAN, K.T.; JAMES, R.B.

    2007-05-04

    One important mission of the Department of Energy's National Nuclear Security Administration is to develop reliable gamma-ray detectors to meet the widespread needs of users for effective techniques to detect and identify special nuclear- and radioactive-materials. Accordingly, the Nonproliferation and National Security Department at Brookhaven National Laboratory was tasked to evaluate existing technology and to develop improved room-temperature detectors based on semiconductors, such as CdZnTe (CZT). Our research covers two important areas: Improving the quality of CZT material, and exploring new CZT-based gamma-ray detectors. In this paper, we report on our recent findings from the material characterization and tests of actual CZT devices fabricated in our laboratory and from materials/detectors supplied by different commercial vendors. In particular, we emphasize the critical role of secondary phases in the current CZT material and issues in fabricating the CZT detectors, both of which affect their performance.

  8. Physical model for the incoherent writing/erasure of cavity solitons in semiconductor optical amplifiers.

    Science.gov (United States)

    Barbay, S; Kuszelewicz, R

    2007-09-17

    We present a physical mechanism that explains the recent observations of incoherent writing and erasure of Cavity Solitons in a semiconductor optical amplifier [S. Barbay et al, Opt. Lett. 31, 1504-1506 (2006)]. This mechanism allows to understand the main observations of the experiment. In particular it perfectly explains why writing and erasure are possible as a result of a local perturbation in the carrier density, and why a delay is observed along with the writing process. Numerical simulations in 1D are performed and show very good qualitative agreement with the experimental observations.

  9. Extracting physical properties of arbitrarily shaped laser-doped micro-scale areas in semiconductors

    International Nuclear Information System (INIS)

    Heinrich, Martin; Kluska, Sven; Hameiri, Ziv; Hoex, Bram; Aberle, Armin G.

    2013-01-01

    We present a method that allows the extraction of relevant physical properties such as sheet resistance and dopant profile from arbitrarily shaped laser-doped micro-scale areas formed in semiconductors with a focused pulsed laser beam. The key feature of the method is to use large laser-doped areas with an identical average number of laser pulses per area (laser pulse density) as the arbitrarily shaped areas. The method is verified using sheet resistance measurements on laser-doped silicon samples. Furthermore, the method is extended to doping with continuous-wave lasers by using the average number of passes per area or density of passes

  10. Silicon carbide: A unique platform for metal-oxide-semiconductor physics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang [Institute for Advanced Materials, Devices and Nanotechnology, Rutgers University, Piscataway, New Jersey 08854 (United States); Tuttle, Blair R. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); Dhar, Sarit [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

    2015-06-15

    A sustainable energy future requires power electronics that can enable significantly higher efficiencies in the generation, distribution, and usage of electrical energy. Silicon carbide (4H-SiC) is one of the most technologically advanced wide bandgap semiconductor that can outperform conventional silicon in terms of power handling, maximum operating temperature, and power conversion efficiency in power modules. While SiC Schottky diode is a mature technology, SiC power Metal Oxide Semiconductor Field Effect Transistors are relatively novel and there is large room for performance improvement. Specifically, major initiatives are under way to improve the inversion channel mobility and gate oxide stability in order to further reduce the on-resistance and enhance the gate reliability. Both problems relate to the defects near the SiO{sub 2}/SiC interface, which have been the focus of intensive studies for more than a decade. Here we review research on the SiC MOS physics and technology, including its brief history, the state-of-art, and the latest progress in this field. We focus on the two main scientific problems, namely, low channel mobility and bias temperature instability. The possible mechanisms behind these issues are discussed at the device physics level as well as the atomic scale, with the support of published physical analysis and theoretical studies results. Some of the most exciting recent progress in interface engineering for improving the channel mobility and fundamental understanding of channel transport is reviewed.

  11. Semiconductor spintronics

    CERN Document Server

    Xia, Jianbai; Chang, Kai

    2012-01-01

    Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.

  12. Proceedings of the 10. National Meeting on Condensed Matter Physics

    International Nuclear Information System (INIS)

    1987-01-01

    Papers on: amorphous materials; atomic and molecular physics; biophysics; crystallography; defects, growth and characterization of crystals; statistical physics; instrumentation; liquid crystals; magnetism; science of materials/mechanical properties; metals and alloys; optic; magnetic resonance; and semiconductors are presented. (M.C.K.) [pt

  13. Amorphous semiconductors for particle detection: Physical and technical limits and possibilities

    International Nuclear Information System (INIS)

    Equer, B.; Karar, A.

    1989-01-01

    Amorphous silicon is used, at an industrial level, in at least three different fields of application: photovoltaic cells, flat TV screens and line scanners for image processing. In the last two cases, thin film transistors (TFT) are produced with the same technology. Particle detection with amorphous silicon has been demonstrated, but present performances are limited to ionizing particles. In this paper, we discuss the physical basis of amorphous semiconductors and the possible future development that can be expected on the basis of the existing technology. It is concluded that substitution of amorphous for crystalline silicon brings no clear advantage, if possible at all. Positive assets are to be found in using specific properties of thin layers: large area structures like arrays of photodiodes with associated readout are in the state of the art; vertical structures alternating layers of differently doped materials and/or of different semiconductors can be produced by the same technique. The development of large area pixel detectors is technically feasible but requires a very large effort. A joint development effort with industries involved in X-ray detection and 2D photodetectors might be the most appropriate solution. (orig.)

  14. An overview of semiconductor bridge, SCB, applications at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W. Jr.; Grubelich, M.C.; Harris, S.M.; Merson, J.A.; Weinlein, J.H.

    1995-05-01

    The semiconductor bridge, SCB, developed by Sandia National Laboratories is a maturing technology now being used in several applications by Sandia customers. Most applications arose because of a need at the system level to provide explosive assemblies that were light weight, small volume, low cost and required small quantities of electrical energy to function -- for the purposes of this paper we define an explosive assembly to mean the combination of the firing set and an explosive component. As a result, and because conventional firing systems could not meet the stringent size, weight and energy requirements of our customers, we designed and are investigating SCB applications that range from devices for Sandia applications to igniters for fireworks. We present in this paper an overview of SCB technology with specific examples of the system designed for our customers to meet modern requirements that sophisticated explosive systems must satisfy in today`s market environments.

  15. Effect of pressure on some physical properties of gallium based semiconductors

    International Nuclear Information System (INIS)

    Vyas, P S; Thakore, B Y; Jani, A R; Gajjar, P N

    2012-01-01

    The gallium based semiconductor compounds are very useful materials for optical spectroscopy and optoelectronic applications, we have studied the effect of pressure on various physical properties like total energy, static bulk modulus, energy band gap at the point X on the Jones-zone face, pressure derivative of bulk modulus and equation of state of gallium based binary compounds GaSb, GaAs, GaP and GaN using pseudopotential theory beyond second order with our well established single parametric model potential. We have incorporated Nagy's static local field correction function to include exchange and correlation effects. The results are compared with those obtained using few other local field correction functions. The present results agree satisfactorily with available experimental and other such theoretical data confirming the application.

  16. 2nd National Conference on Theoretical Physics. Abstracts Book

    International Nuclear Information System (INIS)

    Grecu, Alexandru Tudor

    2004-01-01

    The 2nd National Conference on Theoretical Physics was held on 26-29 August 2004 in Constanta, Romania. The addressed physics fields within the INIS scope are as follows: classical and quantum mechanics, general physics, physics of elementary particles and fields, nuclear physics and radiation physics, classical and quantum mechanics, general physics, atomic and molecular physics, condensed matter physics

  17. N.G. Basov and early works on semiconductor lasers at P.N. Lebedev Physics Institute

    International Nuclear Information System (INIS)

    Eliseev, P G

    2012-01-01

    A survey is presented of works on creation and investigation of semiconductor lasers during 1957 – 1977 at the P.N. Lebedev Physics Institute. Many of these works were initiated by N.G. Basov, starting from pre-laser time, when N.G. Basov and his coworkers formulated principal conditions of creation of lasers on interband transitions in semiconductors. Main directions of further works were diode lasers based on various materials and structures, their characteristics of output power, high-speed operation and reliability. (special issue devoted to the 90th anniversary of n.g. basov)

  18. Plasma Physics at the National Science Foundation

    Science.gov (United States)

    Lukin, Vyacheslav

    2017-10-01

    The Town Meeting on Plasma Physics at the National Science Foundation will provide an opportunity for Q&A about the variety of NSF programs and solicitations relevant to a broad cross-section of the academic plasma science community, from graduating college seniors to senior leaders in the field, and from plasma astrophysics to basic physics to plasma engineering communities. We will discuss recent NSF-hosted events, research awards, and multi-agency partnerships aimed at enabling the progress of science in plasma science and engineering. Future outlook for plasma physics and broader plasma science support at NSF, with an emphasis on how you can help NSF to help the community, will be speculated upon within the uncertainty of the federal budgeting process.

  19. Physics for computer science students with emphasis on atomic and semiconductor physics

    CERN Document Server

    Garcia, Narciso

    1991-01-01

    This text is the product of several years' effort to develop a course to fill a specific educational gap. It is our belief that computer science students should know how a computer works, particularly in light of rapidly changing tech­ nologies. The text was designed for computer science students who have a calculus background but have not necessarily taken prior physics courses. However, it is clearly not limited to these students. Anyone who has had first-year physics can start with Chapter 17. This includes all science and engineering students who would like a survey course of the ideas, theories, and experiments that made our modern electronics age possible. This textbook is meant to be used in a two-semester sequence. Chapters 1 through 16 can be covered during the first semester, and Chapters 17 through 28 in the second semester. At Queens College, where preliminary drafts have been used, the material is presented in three lecture periods (50 minutes each) and one recitation period per week, 15 weeks p...

  20. Optoelectronic device physics and technology of nitride semiconductors from the UV to the terahertz

    Science.gov (United States)

    Moustakas, Theodore D.; Paiella, Roberto

    2017-10-01

    This paper reviews the device physics and technology of optoelectronic devices based on semiconductors of the GaN family, operating in the spectral regions from deep UV to Terahertz. Such devices include LEDs, lasers, detectors, electroabsorption modulators and devices based on intersubband transitions in AlGaN quantum wells (QWs). After a brief history of the development of the field, we describe how the unique crystal structure, chemical bonding, and resulting spontaneous and piezoelectric polarizations in heterostructures affect the design, fabrication and performance of devices based on these materials. The heteroepitaxial growth and the formation and role of extended defects are addressed. The role of the chemical bonding in the formation of metallic contacts to this class of materials is also addressed. A detailed discussion is then presented on potential origins of the high performance of blue LEDs and poorer performance of green LEDs (green gap), as well as of the efficiency reduction of both blue and green LEDs at high injection current (efficiency droop). The relatively poor performance of deep-UV LEDs based on AlGaN alloys and methods to address the materials issues responsible are similarly addressed. Other devices whose state-of-the-art performance and materials-related issues are reviewed include violet-blue lasers, ‘visible blind’ and ‘solar blind’ detectors based on photoconductive and photovoltaic designs, and electroabsorption modulators based on bulk GaN or GaN/AlGaN QWs. Finally, we describe the basic physics of intersubband transitions in AlGaN QWs, and their applications to near-infrared and terahertz devices.

  1. Physics and Chemistry on Well-Defined Semiconductor and Oxide Surfaces

    Science.gov (United States)

    Chen, Peijun

    High resolution electron energy loss spectroscopy (HREELS) and other surface spectroscopic techniques have been employed to investigate the following two classes of surface/interface phenomena on well-defined semiconductor and oxide surfaces: (i) the fundamental physical and chemical processes involved in gas-solid interaction on silicon single crystal surfaces, and (ii) the physical and chemical properties of metal-oxide interfaces. The particular systems reported in this dissertation are: NH_3, PH_3 and B_ {10}H_{14} on Si(111)-(7 x 7); NH_3 on Si(100) -(2 x 1); atomic H on Si(111)-(7 x 7) and boron-modified Si(111); Al on Al_2O_3 and Sn on SiO_2.. On silicon surfaces, the surface dangling bonds function as the primary adsorption sites where surface chemical processes take place. The unambiguous identification of surface species by vibrational spectroscopy allows the elementary steps involved in these surface chemical processes to be followed on a molecular level. For adsorbate molecules such as NH_3 and PH_3, the nature of the initial low temperature (100 -300 K) adsorption is found to be dissociative, while that for B_{10}H_ {14} is non-dissociative. This has been deduced based upon the presence (or absence) of specific characteristic vibrational mode(s) on surface. By following the evolution of surface species as a function of temperature, the elementary steps leading to silicon nitride thin film growth and doping of silicon are elucidated. In the case of NH_3 on Si(111)-(7 x 7) and Si(100)-(2 x 1), a detailed understanding on the role of substrate surface structure in controlling the surface reactivity has been gained on the basis of a Si adatom backbond-strain relief mechanism on the Si(111) -(7 x 7). The electronic modification to Si(111) surface by subsurface boron doping has been shown to quench its surface chemistry, even for the most aggressive atomic H. This discovery is potentially meaningful to the technology of gas-phase silicon etching. The

  2. Proceedings of the eighth national conference on research in physics

    International Nuclear Information System (INIS)

    2005-01-01

    This is a book of abstracts of the oral presentations that were presented during the eighth national conference on research in physics that was held from 20 to 23 deecember 2005 in Tunisia (Elkantaoui- Sousse). The following themes were covered : Nuclear and theoretical physics; Optical, molecular and atomic physics; Condensed matter physics; Soft matter physics; Mechanis; Thermal transfert; Electronics; physics engineering

  3. Proceedings of the Ninth National Conference on Research in Physics

    International Nuclear Information System (INIS)

    2008-01-01

    This is a book of abstracts of the oral presentations that were presented during the ninth national conference on research in physics that was held from 17 to 20 mars 2008 in Tunisia (Yasmine Hammamet). The following themes were covered : Nuclear and theoretical physics; optical, molecular and atomic physics; condensed matter physics; Soft matter physics; Mechanics; Thermal transfer; Electronics; physics engineering

  4. Nano-scaled semiconductor devices physics, modelling, characterisation, and societal impact

    CERN Document Server

    Gutiérrez-D, Edmundo A

    2016-01-01

    This book describes methods for the characterisation, modelling, and simulation prediction of these second order effects in order to optimise performance, energy efficiency and new uses of nano-scaled semiconductor devices.

  5. Fundamentals of semiconductor devices

    CERN Document Server

    Lindmayer, Joseph

    1965-01-01

    Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

  6. Coherent tools for physics-based simulation and characterization of noise in semiconductor devices oriented to nonlinear microwave circuit CAD

    Science.gov (United States)

    Riah, Zoheir; Sommet, Raphael; Nallatamby, Jean C.; Prigent, Michel; Obregon, Juan

    2004-05-01

    We present in this paper a set of coherent tools for noise characterization and physics-based analysis of noise in semiconductor devices. This noise toolbox relies on a low frequency noise measurement setup with special high current capabilities thanks to an accurate and original calibration. It relies also on a simulation tool based on the drift diffusion equations and the linear perturbation theory, associated with the Green's function technique. This physics-based noise simulator has been implemented successfully in the Scilab environment and is specifically dedicated to HBTs. Some results are given and compared to those existing in the literature.

  7. Quantum wells, wires and dots theoretical and computational physics of semiconductor nanostructures

    CERN Document Server

    Harrison, Paul

    2016-01-01

    Quantum Wells, Wires and Dots provides all the essential information, both theoretical and computational, to develop an understanding of the electronic, optical and transport properties of these semiconductor nanostructures. The book will lead the reader through comprehensive explanations and mathematical derivations to the point where they can design semiconductor nanostructures with the required electronic and optical properties for exploitation in these technologies. This fully revised and updated 4th edition features new sections that incorporate modern techniques and extensive new material including: - Properties of non-parabolic energy bands - Matrix solutions of the Poisson and Schrodinger equations - Critical thickness of strained materials - Carrier scattering by interface roughness, alloy disorder and impurities - Density matrix transport modelling -Thermal modelling Written by well-known authors in the field of semiconductor nanostructures and quantum optoelectronics, this user-friendly guide is pr...

  8. Proceedings of the 14. National Meeting on Condensed Matter Physics. v.2

    International Nuclear Information System (INIS)

    1991-01-01

    Studies on atomic and molecular physics, crystallography, statistical physics and critical phenomena, instrumentation, liquid crystals, magnetism, metals and alloys, magnetic resonance, superconductivity and semi-conductors are presented. (M.C.R.)

  9. Proceedings of Republic conference (with participation of scientists from Commonwealth of Independent States countries) 'Modern problems of semiconductor physics', dedicated for twentieth anniversary of independence of Republic Uzbekistan

    International Nuclear Information System (INIS)

    Matchanov, A.T.; Tagaev, M.B.; Ismaylov, K.A.

    2011-11-01

    Republic conference with participation of scientists from Commonwealth of Independent States countries 'Modern problems of semiconductor physics', dedicated for twentieth anniversary of independence of Republic Uzbekistan was held on 23-25 November, 2011 in Nukus, Uzbekistan. Specialists and young scientists from universities and academic research institutes discussed various aspects of modern problems of semiconductor physics. More than 100 talks were presented in the meeting on the following subjects: solid state physics, physics of condensed matter and nano materials; educational tools and information technologies. (K.M.)

  10. International Conference on the Physics of Semiconductors (17th) Held in San Francisco, California on August 6-10, 1984

    Science.gov (United States)

    1984-09-30

    Levels of Two-Dimensional Holes in GaAs - (A[Ga)As Quantum Well Heterostructures 219 11:00 M. A. Chin , V. Narayanamurti, H. L. Stormer, A. C. Gossard...W. Chye , P. Skeath, C. Y. Su and I. Lindau, J. Vac. Sci. Technol. 16, 1422 (1979). 121 17th International Conference on the Physics of Semiconductors...DIMENSIONAL HOLE GAS M. A. Chin , V. Narayanamurti, H. L. Stormer and A. C. Gossard AT&T Bell Laboratories, Murray Hill, NJ 07974 The enhanced electron

  11. The German Physical Society Under National Socialism

    Science.gov (United States)

    Hoffmann, Dieter; Walker, Mark

    2004-12-01

    The history of the German Physical Society from 1933 to 1945 is not the same as a comprehensive history of physics under Adolf Hitler, but it does reflect important aspects of physicists' work and life during the Third Reich.

  12. Growth of Wide Band Gap II-VI Compound Semiconductors by Physical Vapor Transport

    Science.gov (United States)

    Su, Ching-Hua; Sha, Yi-Gao

    1995-01-01

    The studies on the crystal growth and characterization of II-VI wide band gap compound semiconductors, such as ZnTe, CdS, ZnSe and ZnS, have been conducted over the past three decades. The research was not quite as extensive as that on Si, III-V, or even narrow band gap II-VI semiconductors because of the high melting temperatures as well as the specialized applications associated with these wide band gap semiconductors. In the past several years, major advances in the thin film technology such as Molecular Beam Epitaxy (MBE) and Metal Organic Chemical Vapor Deposition (MOCVD) have demonstrated the applications of these materials for the important devices such as light-emitting diode, laser and ultraviolet detectors and the tunability of energy band gap by employing ternary or even quaternary systems of these compounds. At the same time, the development in the crystal growth of bulk materials has not advanced far enough to provide low price, high quality substrates needed for the thin film growth technology.

  13. Nonlinear effects in ultralong semiconductor optical amplifiers for optical communications. Physics and applications

    Energy Technology Data Exchange (ETDEWEB)

    Runge, Patrick

    2010-10-19

    The presented work discusses physical properties of ultralong semiconductor optical amplifiers (UL-SOAs) and some of their possible applications in optical communication systems. At the beginning of this thesis the analytical framework for the optical properties of UL-SOAs is presented. Based on this theoretical description, a numerical simulation model is derived used for the investigation of this thesis. To obtain from the simulation model realistic results the important properties of UL-SOAs have to be included, e.g., being the saturation of the main part of the device. In this saturated part of the device, fast intraband effects dominate over the slow interband effects. The intention of UL-SOAs is to make use of these pronounced fast intraband effects in applications. Due to the short relaxation times of the fast intraband effects, they can be used for high-speed signal processing (>20 GBaud). With the help of an additional continuous wave (CW) signal propagating with the data signal in the UL-SOA, the capability for all-optical signal processing with 100 Gbit/s on-off keying RZ-50% pseudo random bit sequence signals has been demonstrated in this thesis. With an optimised device under proper driving conditions, bit pattern effects are negligible compared to the degradation due to amplified spontaneous emission. The suppression of the bit pattern effects can be ascribed to the additional CW signal operating as a holding beam. Investigations of the UL-SOA's driving condition showed that the data signal's extinction ratio (ER) can be regenerated if the two input signals are co-polarised and the data signal has a shorter wavelength than the CW signal. These two and other driving conditions have indicated, that parametric amplification due to four-wave mixing (FWM) (Bogatov-like effect) is the reason for the ER improvement. Moreover, due to the additional CW signal, all-optical wavelength conversion (AOWC) is possible which can be combined with the ER

  14. Semiconductor sensors

    International Nuclear Information System (INIS)

    Hartmann, Frank

    2011-01-01

    Semiconductor sensors have been around since the 1950s and today, every high energy physics experiment has one in its repertoire. In Lepton as well as Hadron colliders, silicon vertex and tracking detectors led to the most amazing physics and will continue doing so in the future. This contribution tries to depict the history of these devices exemplarily without being able to honor all important developments and installations. The current understanding of radiation damage mechanisms and recent R and D topics demonstrating the future challenges and possible technical solutions for the SLHC detectors are presented. Consequently semiconductor sensor candidates for an LHC upgrade and a future linear collider are also briefly introduced. The work presented here is a collage of the work of many individual silicon experts spread over several collaborations across the world.

  15. Semiconductor Optics

    CERN Document Server

    Klingshirn, Claus F

    2012-01-01

    This updated and enlarged new edition of Semiconductor Optics provides an introduction to and an overview of semiconductor optics from the IR through the visible to the UV, including linear and nonlinear optical properties, dynamics, magneto and electrooptics, high-excitation effects and laser processes, some applications, experimental techniques and group theory. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered extend from physics to materials science and optoelectronics. Significantly updated chapters add coverage of current topics such as electron hole plasma, Bose condensation of excitons and meta materials. Over 120 problems, chapter introductions and a detailed index make it the key textbook for graduate students in physics. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered ...

  16. Mathematical Reasoning Requirements in Swedish National Physics Tests

    Science.gov (United States)

    Johansson, Helena

    2016-01-01

    This paper focuses on one aspect of mathematical competence, namely mathematical reasoning, and how this competency influences students' knowing of physics. This influence was studied by analysing the mathematical reasoning requirements upper secondary students meet when solving tasks in national physics tests. National tests are constructed to…

  17. Semiconductors and semimetals intersubband transitions in quantum wells physics and device applications

    CERN Document Server

    Weber, Eicke R; Liu, H C

    1999-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The Willardson and Beer series, as it is widely known, has succeeded in producing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Pro

  18. Quantum Wells, Wires and Dots Theoretical and Computational Physics of Semiconductor Nanostructures

    CERN Document Server

    Harrison, Paul

    2011-01-01

    Quantum Wells, Wires and Dots, 3rd Edition is aimed at providing all the essential information, both theoretical and computational, in order that the reader can, starting from essentially nothing, understand how the electronic, optical and transport properties of semiconductor heterostructures are calculated. Completely revised and updated, this text is designed to lead the reader through a series of simple theoretical and computational implementations, and slowly build from solid foundations, to a level where the reader can begin to initiate theoretical investigations or explanations of their

  19. National Recommendations for Physical Activity and Physical Activity Promotion

    OpenAIRE

    Rütten, Alfred; Pfeifer, Klaus; Banzer, Winfried; Ferrari, Nina; Füzéki, Eszter; Geidl, Wolfgang; Graf, Christine; Hartung, Verena; Klamroth, Sarah; Völker, Klaus; Vogt, Lutz; Abu-Omar, Karim; Burlacu, Ionuţ; Gediga, Günther; Messing, Sven

    2016-01-01

    Always and at any age, regular physical activity can act as a powerful elixir with a beneficial effect on health and well-being. The wide variety of health effects that physical activity can have, for example on our cardiovascular system, back and joints, is scientifically well proven. At the same time, we spend most of our time sitting – at school, at the office or in the car. Our bodies, however, want to be on the move! This fundamental instinct is deeply rooted in human nature and this bas...

  20. 2nd International Conference on Ion Implantation in Semiconductors, Physics and Technology, Fundamental and Applied Aspects

    CERN Document Server

    Graul, Jürgen

    1971-01-01

    In recent years great progress has been made in the field of ion implantation, particularly with respect to applications in semiconductors. It would be impos­ sible not to note the growing interest in this field, both by research groups and those directly concerned with production of devices. Furthermore, as several papers have pointed out, ion implantation and its associated technologies promise exciting advances in the development of new kinds of devices and provide power­ ful new tools for materials investigations. It was, therefore, appropriate to arrange the II. International Conference on Ion Implantation in Semiconductors within the rather short time of one year since the first conference was held in 1970 in Thousand Oaks, California. Although ori­ ginally planned on a small scale with a very limited number of participants, more than two hundred scientists from 15 countries participated in the Conference which was held May 24 - 28, 1971 at the Congress Center in Garmisch-Partenkirchen. This volume c...

  1. 14th National Conference on Physics. Abstracts. Volume 2

    International Nuclear Information System (INIS)

    Calboreanu, Alexandru; Grecu, Dan

    2005-01-01

    The National Conference on Physics 2005, is dedicated to 'The International Year of Physics' by the scientific community of physicists in Romania. Within the frame of this 'Festival of Physics', The First Symposium on Technical Physics and Physical Engineering' TPPE 2005, was organized as a satellite event at the Polytechnic University of Bucharest. As it is well known, the contributed papers to the National Conference on Physics were structured on chapters, corresponding to 'the sections' of The Romanian Society of Physics, their abstracts being then published in a two volume 'Book of Abstracts'. All the chapters of this book, except the 8th and the 9th, can be found in 'Abstracts Volume I'. According to the topics of the TPPE 2005, these two chapters, namely: 8. Technical Physics and Physical Engineering and 9. Physics and Energy are published separately in the 'Abstracts Volume II', but as it can be seen, the unitary character of the Conference is preserved and developed. The most important topics of this second volume are: optoelectronics; advanced materials and technologies; physics, electronics and electrical engineering; physics and mechanical engineering; physics and chemical engineering; physics, information and computer engineering; physics and industry; physics, biology and medical engineering; renewable energy sources and energy efficiency; nuclear engineering. We present the progress made in physics education concerning: physics teaching in technical education; E-learning and modern methods in physics teaching; physics education in schools and universities, in a special section of the first volume of abstracts. Regarding the essential role of physics in the realizing of a knowledge-based society of the new millennium the strengthening of the relationship between researchers and academics becomes thus the main message of this scientific meeting. (P.S.)

  2. Metal semiconductor contacts and devices

    CERN Document Server

    Cohen, Simon S; Einspruch, Norman G

    1986-01-01

    VLSI Electronics Microstructure Science, Volume 13: Metal-Semiconductor Contacts and Devices presents the physics, technology, and applications of metal-semiconductor barriers in digital integrated circuits. The emphasis is placed on the interplay among the theory, processing, and characterization techniques in the development of practical metal-semiconductor contacts and devices.This volume contains chapters that are devoted to the discussion of the physics of metal-semiconductor interfaces and its basic phenomena; fabrication procedures; and interface characterization techniques, particularl

  3. High energy physics at Brookhaven National Lab

    International Nuclear Information System (INIS)

    Samios, N.P.

    1982-01-01

    The AGS is supporting an exciting, vibrant, and vital program. There are at present two modes of operation, Fast Extracted Beam (FEB) with a 1.4 second repetition rate and Slow Extracted Beam (SEB) with a 2 second repetition rate. The average intensity is 8 x 10/sup 12/ protons per pulse with peaks at 10/sup 13/ ppp. The FEB mode is mainly utilized for neutrino physics involving large detectors, 100-200 tons, placed at varying distances from the target, 300 meters and 1 kilometer. In the slow mode there is a one second flat top during which the beam emerges uniformly in time and it is split into four target stations: A, B, C, and D. These four are simultaneously illuminated and the fractions on each can be varied. A listing of the types of approved experiments is presented with their appropriate beam locations. The experimental program ran for 22 weeks. Over 200 users practice their trade at the AGS and the program is sufficiently rich that there is a reasonable chance that one or more experimenters will uncover new results that will change the way we think about particle physics

  4. Contacts to semiconductors

    International Nuclear Information System (INIS)

    Tove, P.A.

    1975-08-01

    Contacts to semiconductors play an important role in most semiconductor devices. These devices range from microelectronics to power components, from high-sensitivity light or radiation detectors to light-emitting of microwave-generating components. Silicon is the dominating material but compound semiconductors are increasing in importance. The following survey is an attempt to classify contact properties and the physical mechanisms involved, as well as fabrication methods and methods of investigation. The main interest is in metal-semiconductor type contacts where a few basic concepts are dealt with in some detail. (Auth.)

  5. Undergraduate Physical Activity and Depressive Symptoms: A National Study

    Science.gov (United States)

    Elliot, Catherine A.; Kennedy, Catherine; Morgan, George; Anderson, Sharon K.; Morris, Debra

    2012-01-01

    Objective: To study the effects of college students' physical activity and gender on depressive and suicidal symptoms. Method: The National College Health Assessment survey was administered to college students nationwide. Data were analyzed with 4x2 ANOVAs and Games-Howell post hoc tests when appropriate. Results: More frequent physical activity…

  6. Proceedings of second national workshop on nuclear structure physics

    International Nuclear Information System (INIS)

    Chintalapudi, S.N.; Jain, A.K.

    1995-01-01

    The Second National Workshop on Nuclear Structure Physics was held at Calcutta during February 7-10 1995. The topics discussed have been quite broad based and covered many areas of nuclear structure physics and radiochemistry. Papers relevant to INIS are indexed separately

  7. Proceedings of national seminar on physics with radioactive ion beams

    International Nuclear Information System (INIS)

    Chintalapudi, S.N.; Shyam, R.

    1991-01-01

    This volume containing the proceedings of the national seminar on physics with radioactive ion beams gives a broad overview of the developments taking place in the area of nuclear physics and accelerator physics with special emphasis on the utilization of radioactive ion beams for various studies. Topics covered include studies on nuclear structure and nuclear astrophysics and the wide ranging applications of radioactive ion beams in these and other areas of nuclear sciences. Papers relevant to INIS are indexed separately

  8. High energy physics at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Samios, N.P.

    1982-01-01

    The high energy plans at BNL are centered around the AGS and ISABELLE, or a variant thereof. At present the AGS is maintaining a strong and varied program. This last year a total of 4 x 10 19 protons were delivered on target in a period of approximately 20 weeks. Physics interest is very strong, half of the submitted proposals are rejected (thereby maintaining high quality experiments) and the program is full over the next two years. The future colliding beam facility will utilize the AGS as an injector and will be a dedicated facility. It will have six intersection regions, run > 10 7 sec/year, and explore a new domain of energy and luminosity. Common to all the considered alternatives is a large aperture proton ring. These possible choices involve pp, ep, and heavy ion variants. The long term philosophy is to run the AGS as much as possible, continuously to upgrade it in performance and reliability, and then to phase it down as the new collider begins operation

  9. Optical properties of single semiconductor nanowires and nanowire ensembles. Probing surface physics by photoluminescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pfueller, Carsten

    2011-06-27

    This thesis presents a detailed investigation of the optical properties of semiconductor nanowires (NWs) in general and single GaN NWs and GaN NW ensembles in particular by photoluminescence (PL) spectroscopy. NWs are often considered as potential building blocks for future nanometer-scaled devices. This vision is based on several attractive features that are generally ascribed to NWs. For instance, they are expected to grow virtually free of strain and defects even on substrates with a large structural mismatch. In the first part of the thesis, some of these expectations are examined using semiconductor NWs of different materials. On the basis of the temperature-dependent PL of Au- and selfassisted GaAs/(Al,Ga)As core-shell NWs, the influence of foreign catalyst particles on the optical properties of NWs is investigated. For the Au-assisted NWs, we find a thermally activated, nonradiative recombination channel, possibly related to Auatoms incorporated from the catalyst. These results indicate the limited suitability of catalyst-assisted NWs for optoelectronic applications. The effect of the substrate choice is studied by comparing the PL of ZnO NWs grown on Si, Al{sub 2}O{sub 3}, and ZnO substrates. Their virtually identical optical characteristics indicate that the synthesis of NWs may indeed overcome the constraints that limit the heteroepitaxial deposition of thin films. The major part of this thesis discusses the optical properties of GaN NWs grown on Si substrates. The investigation of the PL of single GaN NWs and GaN NW ensembles reveals the significance of their large surface-to-volume ratio. Differences in the recombination behavior of GaNNW ensembles and GaN layers are observed. First, the large surface-to-volume ratio is discussed to be responsible for the different recombination mechanisms apparent in NWs. Second, certain optical features are only found in the PL of GaN NWs, but not in that of GaN layers. An unexpected broadening of the donor

  10. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  11. Organic semiconductor crystals.

    Science.gov (United States)

    Wang, Chengliang; Dong, Huanli; Jiang, Lang; Hu, Wenping

    2018-01-22

    Organic semiconductors have attracted a lot of attention since the discovery of highly doped conductive polymers, due to the potential application in field-effect transistors (OFETs), light-emitting diodes (OLEDs) and photovoltaic cells (OPVs). Single crystals of organic semiconductors are particularly intriguing because they are free of grain boundaries and have long-range periodic order as well as minimal traps and defects. Hence, organic semiconductor crystals provide a powerful tool for revealing the intrinsic properties, examining the structure-property relationships, demonstrating the important factors for high performance devices and uncovering fundamental physics in organic semiconductors. This review provides a comprehensive overview of the molecular packing, morphology and charge transport features of organic semiconductor crystals, the control of crystallization for achieving high quality crystals and the device physics in the three main applications. We hope that this comprehensive summary can give a clear picture of the state-of-art status and guide future work in this area.

  12. Biggest semiconductor installed

    CERN Multimedia

    2008-01-01

    Scientists and technicians at the European Laboratory for Particle Physics, commonly known by its French acronym CERN (Centre Europen pour la Recherche Nuclaire), have completed the installation of the largest semiconductor silicon detector.

  13. State of the art in semiconductor detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1990-01-01

    The state of the art in semiconductor detectors for elementary particle physics and X-ray astronomy is briefly reviewed. Semiconductor detectors are divided into two groups; i) classical semiconductor diode detectors and ii) semiconductor memory detectors. Principles of signal formation for both groups of detectors are described and their performance is compared. New developments of silicon detectors are reported here. (orig.)

  14. State of the art in semiconductor detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1989-01-01

    The state of the art in semiconductor detectors for elementary particle physics and x-ray astronomy is briefly reviewed. Semiconductor detectors are divided into two groups; classical semiconductor diode detectors; and semiconductor memory detectors. Principles of signal formation for both groups of detectors are described and their performance is compared. New developments of silicon detectors are reported here. 13 refs., 8 figs

  15. 41st Vietnam National Conference on Theoretical Physics

    International Nuclear Information System (INIS)

    2017-01-01

    Preface The 41 st Vietnam National Conference on Theoretical Physics (NCTP-41) was held during 1-4 August 2016 in Nha Trang, Vietnam. The NCTP-41 was organized by the Institute of Physics, Vietnam Academy of Science and Technology (IOP-VAST) under the support of the Vietnamese Theoretical Physics Society (VTPS). This meeting belongs to a series of annual theoretical physics conferences that started in 1976. The conference has covered a wide range of theoretical physics topics from 4 major fields: • Particle, nuclear and astro- physics, • Molecular physics, quantum optics and quantum computation, • Condensed matter physics, • Soft matter, biological and interdisciplinary physics. 115 participants have participated in the conference. 2 invited talks, 22 oral and 75 poster contributions were presented. This volume contains selected papers contributed by the participants. Editors of the NCTP-41 Proceedings Trinh Xuan Hoang, Hoang Anh Tuan and Vu Ngoc Tuoc Information about Organizer, Sponsor, Honorary Chair and Chair and also lists of committees and participants are available in the PDF (paper)

  16. 76 FR 25521 - National Physical Fitness and Sports Month, 2011

    Science.gov (United States)

    2011-05-05

    ... in our Nation's health and wellness. Participation in sports can strengthen both body and mind, and... live a healthy lifestyle. Through the President's Council on Fitness, Sports and Nutrition, my.... Regular physical activity and good nutrition are essential to staying healthy. A balanced diet and...

  17. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1987-01-01

    In-depth exploration of the implications of carrier populations and Fermi energies examines distribution of electrons in energy bands and impurity levels of semiconductors. Also: kinetics of semiconductors containing excess carriers, particularly in terms of trapping, excitation, and recombination.

  18. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K

    2013-01-01

    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  19. Argonne National Laboratory as an interface between physics and industry

    International Nuclear Information System (INIS)

    Sachs, R.G.

    1976-01-01

    Application of physics to industry requires the involvement of many other disciplines, including chemistry, material sciences, and many other fields of engineering; and the national laboratories in the United States have a mix of such disciplines particularly conducive to such transfer. They have participated in one of the most striking transfers of physics to industry in history, namely, the development of the nuclear power industry. Scientific feasibility of nuclear power was established when the first chain reaction was demonstrated at the Metallurgical Laboratory. Argonne National Laboratory as the successor to the Metallurgical Laboratory has played a major role in transferring the results of this physics experiment to industry, especially in demonstrating engineering feasibility of nuclear power. Major developments in industrial instrumentation have taken place in parallel with the development of nuclear energy, and many of these developments are applicable to other industrial systems as well. The responsibilities of the national laboratories have recently been extended into many energy technologies other than nuclear, offering them the opportunity to serve as an interface for transfer of physics into many new industries. A number of examples are cited. (author)

  20. The proceedings of the 14th national symposium on atomic physics and nuclear physics and the 7th annual meeting on modern physics

    International Nuclear Information System (INIS)

    2002-01-01

    It is the proceedings of the 14th national symposium on atomic physics and nuclear physics and the 7th annual meeting on modern physics. 27 theses are collected in these proceedings. Many of them are related with nuclear physics

  1. Optical orientation in ferromagnet/semiconductor hybrids

    International Nuclear Information System (INIS)

    Korenev, V L

    2008-01-01

    The physics of optical pumping of semiconductor electrons in ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of a ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of a semiconductor. Spin–spin interactions near the ferromagnet/semiconductor interface play a crucial role in the optical readout and the manipulation of ferromagnetism

  2. Optical orientation in ferromagnet/semiconductor hybrids

    Science.gov (United States)

    Korenev, V. L.

    2008-11-01

    The physics of optical pumping of semiconductor electrons in ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of a ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of a semiconductor. Spin-spin interactions near the ferromagnet/semiconductor interface play a crucial role in the optical readout and the manipulation of ferromagnetism.

  3. Optical Orientation in Ferromagnet/Semiconductor Hybrids

    OpenAIRE

    Korenev, V. L.

    2008-01-01

    The physics of optical pumping of semiconductor electrons in the ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of the ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of the semiconductor. Spin-spin interactions near the interface ferromagnet/semiconductor play crucial role in the optical readout and the manipulation of ferromagnetism.

  4. Automating Energy Bandgap Measurements in Semiconductors Using LabVIEW

    Science.gov (United States)

    Garg, Amit; Sharma, Reena; Dhingra, Vishal

    2010-01-01

    In this paper, we report the development of an automated system for energy bandgap and resistivity measurement of a semiconductor sample using Four-Probe method for use in the undergraduate laboratory of Physics and Electronics students. The automated data acquisition and analysis system has been developed using National Instruments USB-6008 DAQ…

  5. National Physical Education Standards: Level of Physical Fitness Male Student Primary School in Malaysia

    OpenAIRE

    Ahmad Hashim; Mohd. Sani Madon; Nur Haziyanti Mohd Khalid; Nelfianty binti Mohd Rashid; Sadzali bin Hassan; Yusop bin Ahmad

    2014-01-01

    This study aims to analyze the level of physical fitness in the development of the National Standards of Physical Education. The study was conducted on 279 primary school boys age 10 years (n = 79), 11 years (n = 94) and 12 years (n = 106) in five randomly selected schools in the state of Perak. FITNESSGRAM was used to test the level of physical fitness among subjects. This includes trunk lift, 90 degree push-ups, modified pull-up, back saver sit and reach and PACER. ANOVA analysis showed a s...

  6. Child physical abuse and adult mental health: a national study.

    Science.gov (United States)

    Sugaya, Luisa; Hasin, Deborah S; Olfson, Mark; Lin, Keng-Han; Grant, Bridget F; Blanco, Carlos

    2012-08-01

    This study characterizes adults who report being physically abused during childhood, and examines associations of reported type and frequency of abuse with adult mental health. Data were derived from the 2000-2001 and 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions, a large cross-sectional survey of a representative sample (N = 43,093) of the U.S. population. Weighted means, frequencies, and odds ratios of sociodemographic correlates and prevalence of psychiatric disorders were computed. Logistic regression models were used to examine the strength of associations between child physical abuse and adult psychiatric disorders adjusted for sociodemographic characteristics, other childhood adversities, and comorbid psychiatric disorders. Child physical abuse was reported by 8% of the sample and was frequently accompanied by other childhood adversities. Child physical abuse was associated with significantly increased adjusted odds ratios (AORs) of a broad range of DSM-IV psychiatric disorders (AOR = 1.16-2.28), especially attention-deficit hyperactivity disorder, posttraumatic stress disorder, and bipolar disorder. A dose-response relationship was observed between frequency of abuse and several adult psychiatric disorder groups; higher frequencies of assault were significantly associated with increasing adjusted odds. The long-lasting deleterious effects of child physical abuse underscore the urgency of developing public health policies aimed at early recognition and prevention. Copyright © 2012 International Society for Traumatic Stress Studies.

  7. Current Reactor Physics Benchmark Activities at the Idaho National Laboratory

    International Nuclear Information System (INIS)

    Bess, John D.; Marshall, Margaret A.; Gorham, Mackenzie L.; Christensen, Joseph; Turnbull, James C.; Clark, Kim

    2011-01-01

    The International Reactor Physics Experiment Evaluation Project (IRPhEP) (1) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) (2) were established to preserve integral reactor physics and criticality experiment data for present and future research. These valuable assets provide the basis for recording, developing, and validating our integral nuclear data, and experimental and computational methods. These projects are managed through the Idaho National Laboratory (INL) and the Organisation for Economic Co-operation and Development Nuclear Energy Agency (OECD-NEA). Staff and students at the Department of Energy - Idaho (DOE-ID) and INL are engaged in the development of benchmarks to support ongoing research activities. These benchmarks include reactors or assemblies that support Next Generation Nuclear Plant (NGNP) research, space nuclear Fission Surface Power System (FSPS) design validation, and currently operational facilities in Southeastern Idaho.

  8. EDITORIAL The 23rd Nordic Semiconductor Meeting The 23rd Nordic Semiconductor Meeting

    Science.gov (United States)

    Ólafsson, Sveinn; Sveinbjörnsson, Einar

    2010-12-01

    A Nordic Semiconductor Meeting is held every other year with the venue rotating amongst the Nordic countries of Denmark, Finland, Iceland, Norway and Sweden. The focus of these meetings remains 'original research and science being carried out on semiconductor materials, devices and systems'. Reports on industrial activity have usually featured. The topics have ranged from fundamental research on point defects in a semiconductor to system architecture of semiconductor electronic devices. Proceedings from these events are regularly published as a topical issue of Physica Scripta. All of the papers in this topical issue have undergone critical peer review and we wish to thank the reviewers and the authors for their cooperation, which has been instrumental in meeting the high scientific standards and quality of the series. This meeting of the 23rd Nordic Semiconductor community, NSM 2009, was held at Háskólatorg at the campus of the University of Iceland, Reykjavik, Iceland, 14-17 June 2009. Support was provided by the University of Iceland. Almost 50 participants presented a broad range of topics covering semiconductor materials and devices as well as related material science interests. The conference provided a forum for Nordic and international scientists to present and discuss new results and ideas concerning the fundamentals and applications of semiconductor materials. The meeting aim was to advance the progress of Nordic science and thus aid in future worldwide technological advances concerning technology, education, energy and the environment. Topics Theory and fundamental physics of semiconductors Emerging semiconductor technologies (for example III-V integration on Si, novel Si devices, graphene) Energy and semiconductors Optical phenomena and optical devices MEMS and sensors Program 14 June Registration 13:00-17:00 15 June Meeting program 09:30-17:00 and Poster Session I 16 June Meeting program 09:30-17:00 and Poster Session II 17 June Excursion and dinner

  9. Semiconductor materials and their properties

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; Verlinden, Pierre; van Sark, Wilfried; Freundlich, Alexandre; Reinders, Angele; Verlinden, Pierre; van Sark, Wilfried; Freundlich, Alexandre

    2017-01-01

    Semiconductor materials are the basic materials which are used in photovoltaic (PV) devices. This chapter introduces solid-state physics and semiconductor properties that are relevant to photovoltaics without spending too much time on unnecessary information. Usually atoms in the group of

  10. Fundamentals of semiconductor lasers

    CERN Document Server

    Numai, Takahiro

    2015-01-01

    This book explains physics under the operating principles of semiconductor lasers in detail based on the experience of the author, dealing with the first manufacturing of phase-shifted DFB-LDs and recent research on transverse modes.   The book also bridges a wide gap between journal papers and textbooks, requiring only an undergraduate-level knowledge of electromagnetism and quantum mechanics, and helps readers to understand journal papers where definitions of some technical terms vary, depending on the paper. Two definitions of the photon density in the rate equations and two definitions of the phase-shift in the phase-shifted DFB-LD are explained, and differences in the calculated results are indicated, depending on the definitions.    Readers can understand the physics of semiconductor lasers and analytical tools for Fabry-Perot LDs, DFB-LDs, and VCSELs and will be stimulated to develop semiconductor lasers themselves.

  11. Photoelectronic properties of semiconductors

    CERN Document Server

    Bube, Richard H

    1992-01-01

    The interaction between light and electrons in semiconductors forms the basis for many interesting and practically significant properties. This book examines the fundamental physics underlying this rich complexity of photoelectronic properties of semiconductors, and will familiarise the reader with the relatively simple models that are useful in describing these fundamentals. The basic physics is also illustrated with typical recent examples of experimental data and observations. Following introductory material on the basic concepts, the book moves on to consider a wide range of phenomena, including photoconductivity, recombination effects, photoelectronic methods of defect analysis, photoeffects at grain boundaries, amorphous semiconductors, photovoltaic effects and photoeffects in quantum wells and superlattices. The author is Professor of Materials Science and Electrical Engineering at Stanford University, and has taught this material for many years. He is an experienced author, his earlier books having fo...

  12. Synthesis, characterization, and photo-physical properties of nano-crystallites of CdyZn1-yS semiconductors

    International Nuclear Information System (INIS)

    Cizeron, Joel

    1996-01-01

    This research thesis reports the study of the synthesis of particles of semiconductor with a hybrid composition (Cd y Zn 1-y S) in an inverse micellar system. This system is made of nano-scopic water droplets suspended in oil by Brownian movement. Inverse micelles of AOT/water/alkane have been successfully used in laboratory to synthesize semiconductor particles (CdS, Ag 2 S, AgI, PbS) and metallic particles (Ag, Cu, Co) with a diameter of few nanometers. The objective has been to demonstrate the feasibility of synthesises of solid solution with a composition controlled by colloidal techniques. It was then possible to identify new information on the mechanism which governs the size of semiconductor particles. Optical properties of these particles were then studied. These nano-particles exhibit a displacement of their exciton towards high energies; it is the so-called size quantum effect. This effect has been analysed for the particles and their fluorescence [fr

  13. Proposal for the establishment of a national underground physics laboratory

    International Nuclear Information System (INIS)

    Mann, A.K.; Sharp, R.R. Jr.

    1982-01-01

    Advances in elementary particles physics and astrophysics during the past decade have indicated certain areas in those fields in which experiments of high potential significance, albeit great difficulty, need to be done. In general, these are experiments that seek to uncover rare, new physical phenomena, or to study quantitatively phenomena that are especially difficult to observe. Among them are: (1) the study of solar and other cosmic neutrinos; (2) the search for nucleon instability; (3) the search for non-zero neutrino mass through the study of neutrino stability and double beta-decay; and (4) intensive searches for and attempts to measure accurately very energetic, rare elementary particle interactions such as may be manifested, for example, in the so-called Centauro events. The nature of these experiments requires that they be shielded from the intense flux of cosmic ray muons and air showers on the earth's surface, and therefore that the experimental apparatus be located deep underground or in the deep sea. However, for most of the experiments, and the apparatus also needs to be very large in mass and volume, and highly instrumented to achieve the necessary measurement capability. It is proposed to establish a laboratory deep underground of sufficient scope to be capable of housing and maintaining a variety of experiments that employ the most advanced technology. A specific channel is discussed whereby a national underground physics laboratory might be formed. The desirable characteristics of such a laboratory are described, and a possible location is recommended. Detailed cost estimates are provided

  14. Semiconductor Manufacturing equipment introduction

    International Nuclear Information System (INIS)

    Im, Jong Sun

    2001-02-01

    This book deals with semiconductor manufacturing equipment. It is comprised of nine chapters, which are manufacturing process of semiconductor device, history of semiconductor manufacturing equipment, kinds and role of semiconductor manufacturing equipment, construction and method of semiconductor manufacturing equipment, introduction of various semiconductor manufacturing equipment, spots of semiconductor manufacturing, technical elements of semiconductor manufacturing equipment, road map of technology of semiconductor manufacturing equipment and semiconductor manufacturing equipment in the 21st century.

  15. Semiconductor lasers stability, instability and chaos

    CERN Document Server

    Ohtsubo, Junji

    2017-01-01

    This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Applications of semiconductor laser chaos, control and noise, and semiconductor lasers are also demonstrated. Semiconductor lasers with new structures, such as vertical-cavity surface-emitting lasers and broad-area semiconductor lasers, are intriguing and promising devices. Current topics include fast physical number generation using chaotic semiconductor lasers for secure communication, development of chaos, quantum-dot semiconductor lasers and quantum-cascade semiconductor lasers, and vertical-cavity surface-emitting lasers. This fourth edition has been significantly expanded to reflect the latest developments. The fundamental theory of laser chaos and the chaotic dynamics in se...

  16. Physics and national socialism an anthology of primary sources

    CERN Document Server

    1996-01-01

    This anthology of primary sources is a collection of 121 documents in English translation portraying the role of physics, both perceived and actual, in the Nazi state. These texts were written predominantly by influential German scientists, particularly physicists, both inside and outside Germany in the period from 1933 to 1945. The semipopular articles, private correspondence, and official memoranda selected for the volume reflect the contemporary developments in science as well as the change in political climate and working conditions after the National Socialists' rise to power. The extensive annotation is clearly distinguished from the original text, and the appendix provides an aid to the reader with biographical information on the more important figures and brief outlines of frequently mentioned institutions, journals and companies. The introduction surveys the latest results in the secondary literature.   ------    (…) the envisaged audience includes not only scholars and students of science, hist...

  17. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  18. Fusion plasma physics research on the H-1 national facility

    International Nuclear Information System (INIS)

    Harris, J.

    1998-01-01

    Full text: Australia has a highly leveraged fusion plasma research program centred on the H-1 National Facility device at the ANU. H-1 is a heliac, a novel helical axis stellarator that was experimentally pioneered in Australia, but has a close correlation with the worldwide research program on toroidal confinement of fusion grade plasma. Experiments are conducted on H-1 by university researchers from the Australian Fusion Research Group (comprising groups from the ANU, the Universities of Sydney, Western Sydney, Canberra, New England, and Central Queensland University) under the aegis of AINSE; the scientists also collaborate with fusion researchers from Japan and the US. Recent experiments on H-1 have focused on improved confinement modes that can be accessed at very low powers in H-1, but allow the study of fundamental physics effects seen on much larger machines at higher powers. H-1 is now being upgraded in magnetic field and heating power, and will be able to confine hotter plasmas beginning in 1999, offering greatly enhanced research opportunities for Australian plasma scientists and engineers, with substantial spillover of ideas from fusion research into other areas of applied physics and engineering

  19. Semiconductor spintronics

    International Nuclear Information System (INIS)

    Fabian, J.; Abiague, A.M.; Ertler, Ch.; Stano, P.; Zutic, I.

    2007-01-01

    Spintronics refers commonly to phenomena in which the spin of electrons in a solid state environment plays the determining role. In a more narrow sense spintronics is an emerging research field of electronics: spintronics devices are based on a spin control of electronics, or on an electrical and optical control of spin of magnetism. While metal spintronics has already found its niche in the computer industry - giant magnetoresistance systems are used as hard disk read heads - semiconductor spintronics is vet demonstrate its full potential. This review presents selected themes of semiconductor spintronics, introducing important concepts in spin transport, spin transport, spin injection. Silsbee-Johnson spin-charge coupling, and spin-dependent tunneling, as well as spin relaxation and spin dynamics. The most fundamental spin-dependent interaction in nonmagnetic semiconductors is spin-orbit coupling. Depending on the crystal symmetries of the material, as well as on the structural properties of semiconductor based heterostructures, the spin-orbit coupling takes on different functional forms, giving a nice playground of effective spin-orbit Hamiltonians. The effective Hamiltonians for the most relevant classes of materials and heterostructures are derived here from realistic electronic band structure descriptions. Most semiconductor device systems are still theoretical concepts, waiting for experimental demonstrations. A review of selected proposed, and a few demonstrated devices is presented, with detailed description of two important classes: magnetic resonant tunnel structures and bipolar magnetic diodes and transistors. In view of the importance of ferromagnetic semiconductor material, a brief discussion of diluted magnetic semiconductors is included. In most cases the presentation is of tutorial style, introducing the essential theoretical formalism at an accessible level, with case-study-like illustrations of actual experimental results, as well as with brief

  20. Microcavity Plasma Devices and Arrays Fabricated in Semiconductor, Ceramic, or Metal/polymer Structures: A New Realm of Plasma Physics and Photonics Applications

    International Nuclear Information System (INIS)

    Eden, J. G.

    2005-01-01

    Micro discharge, or microcavity plasma, is the broad term that has come to be associated with an emerging class of glow discharge devices in which the characteristic spatial dimension of the plasma is nominally ) dia. Si wafers and operated in the rare gases and Ar/N2 gas mixtures. Also, photodetection in the ultraviolet, visible and near-infrared with microplasma devices has been observed by interfacing a low temperature plasma with a semiconductor. Carbon nanotubes grown directly within the microcavity of microplasma devices improve all key performance parameters of the device, and nanoporous Al2O3 grown onto Al by wet chemical processing yields microplasma devices of exceptional stability and lifetime. The opportunities such structures offer for accessing new avenues in plasma physics and photonics will be discussed. (Author)

  1. Physics results from the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Kaye, S.; Bell, M.

    2000-01-01

    The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a ∼ 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI), and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-β t and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA, stored energies up to 55 kJ, β t ∼ 10%, and a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and β t =21% were produced

  2. Advances in engineering nanometrology at the National Physical Laboratory

    Science.gov (United States)

    Leach, Richard K.; Claverley, James; Giusca, Claudiu; Jones, Christopher W.; Nimishakavi, Lakshmi; Sun, Wenjuan; Tedaldi, Matthew; Yacoot, Andrew

    2012-07-01

    The National Physical Laboratory, UK, has been active in the field of engineering nanometrology for a number of years. A summary of progress over the last five years is presented in this paper and the following research projects discussed in detail. (1) Development of an infrastructure for the calibration of instruments for measuring areal surface topography, along with the development of areal software measurement standards. This work comprises the use of the optical transfer function and a technique for the simultaneous measurement of topography and the phase change on reflection, allowing composite materials to be measured. (2) Development of a vibrating micro-CMM probe with isotropic probing reaction and the ability to operate in a non-contact mode. (3) A review of x-ray computed tomography and its use in dimensional metrology. (4) The further development of a metrology infrastructure for atomic force microscopy and the development of an instrument for the measurement of the effect of the probe-surface interaction. (5) Traceable measurement of displacement using optical and x-ray interferometry to picometre accuracy. (6) Development of an infrastructure for low-force metrology, including the development of appropriate transfer artefacts.

  3. Advances in engineering nanometrology at the National Physical Laboratory

    International Nuclear Information System (INIS)

    Leach, Richard K; Claverley, James; Giusca, Claudiu; Jones, Christopher W; Nimishakavi, Lakshmi; Sun, Wenjuan; Tedaldi, Matthew; Yacoot, Andrew

    2012-01-01

    The National Physical Laboratory, UK, has been active in the field of engineering nanometrology for a number of years. A summary of progress over the last five years is presented in this paper and the following research projects discussed in detail. (1) Development of an infrastructure for the calibration of instruments for measuring areal surface topography, along with the development of areal software measurement standards. This work comprises the use of the optical transfer function and a technique for the simultaneous measurement of topography and the phase change on reflection, allowing composite materials to be measured. (2) Development of a vibrating micro-CMM probe with isotropic probing reaction and the ability to operate in a non-contact mode. (3) A review of x-ray computed tomography and its use in dimensional metrology. (4) The further development of a metrology infrastructure for atomic force microscopy and the development of an instrument for the measurement of the effect of the probe–surface interaction. (5) Traceable measurement of displacement using optical and x-ray interferometry to picometre accuracy. (6) Development of an infrastructure for low-force metrology, including the development of appropriate transfer artefacts. (paper)

  4. Physics Design of the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    Neilson, G.H.; Zarnstorff, M.C.; Lyon, J.F.

    2002-01-01

    Compact quasi-axisymmetric stellarators offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio approximately 4.4 and average elongation approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for b > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at b = 4% (the rest is from the coils). Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties

  5. Shock and Detonation Physics at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, David L [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve A [Los Alamos National Laboratory

    2012-08-22

    WX-9 serves the Laboratory and the Nation by delivering quality technical results, serving customers that include the Nuclear Weapons Program (DOE/NNSA), the Department of Defense, the Department of Homeland Security and other government agencies. The scientific expertise of the group encompasses equations-of-state, shock compression science, phase transformations, detonation physics including explosives initiation, detonation propagation, and reaction rates, spectroscopic methods and velocimetry, and detonation and equation-of-state theory. We are also internationally-recognized in ultra-fast laser shock methods and associated diagnostics, and are active in the area of ultra-sensitive explosives detection. The facility capital enabling the group to fulfill its missions include a number of laser systems, both for laser-driven shocks, and spectroscopic analysis, high pressure gas-driven guns and powder guns for high velocity plate impact experiments, explosively-driven techniques, static high pressure devices including diamond anvil cells and dilatometers coupled with spectroscopic probes, and machine shops and target fabrication facilities.

  6. Oxide semiconductors

    CERN Document Server

    Svensson, Bengt G; Jagadish, Chennupati

    2013-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scient

  7. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1962-01-01

    Semiconductor Statistics presents statistics aimed at complementing existing books on the relationships between carrier densities and transport effects. The book is divided into two parts. Part I provides introductory material on the electron theory of solids, and then discusses carrier statistics for semiconductors in thermal equilibrium. Of course a solid cannot be in true thermodynamic equilibrium if any electrical current is passed; but when currents are reasonably small the distribution function is but little perturbed, and the carrier distribution for such a """"quasi-equilibrium"""" co

  8. Electronic structure of semiconductor interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Herman, F

    1983-02-01

    The study of semiconductor interfaces is one of the most active and exciting areas of current semiconductor research. Because interfaces play a vital role in modern semiconductor technology (integrated circuits, heterojunction lasers, solar cells, infrared detectors, etc.), there is a strong incentive to understand interface properties at a fundamental level and advance existing technology thereby. At the same time, technological advances such as molecular beam epitaxy have paved the way for the fabrication of semiconductor heterojunctions and superlattices of novel design which exhibit unusual electronic, optical, and magnetic properties and offer unique opportunities for fundamental scientific research. A general perspective on this subject is offered treating such topics as the atomic and electronic structure of semiconductor surfaces and interfaces; oxidation and oxide layers; semiconductor heterojunctions and superlattices; rectifying metal-semiconductor contacts; and interface reactions. Recent progress is emphasized and some future directions are indicated. In addition, the role that large-scale scientific computation has played in furthering our theoretical understanding of semiconductor surfaces and interfaces is discussed. Finally, the nature of theoretical models, and the role they play in describing the physical world is considered.

  9. Electronic structure of semiconductor interfaces

    International Nuclear Information System (INIS)

    Herman, F.

    1983-01-01

    The study of semiconductor interfaces is one of the most active and exciting areas of current semiconductor research. Because interfaces play a vital role in modern semiconductor technology (integrated circuits, heterojunction lasers, solar cells, infrared detectors, etc.), there is a strong incentive to understand interface properties at a fundamental level and advance existing technology thereby. At the same time, technological advances such as molecular beam epitaxy have paved the way for the fabrication of semiconductor heterojunctions and superlattices of novel design which exhibit unusual electronic, optical, and magnetic properties and offer unique opportunities for fundamental scientific research. A general perspective on this subject is offered treating such topics as the atomic and electronic structure of semiconductor surfaces and interfaces; oxidation and oxide layers; semiconductor heterojunctions and superlattices; rectifying metal-semiconductor contacts; and interface reactions. Recent progress is emphasized and some future directions are indicated. In addition, the role that large-scale scientific computation has played in furthering our theoretical understanding of semiconductor surfaces and interfaces is discussed. Finally, the nature of theoretical models, and the role they play in describing the physical world is considered. (Author) [pt

  10. Semiconductor Detectors

    International Nuclear Information System (INIS)

    Cortina, E.

    2007-01-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  11. Physical, Ecological, and Societal Indicators for the National Climate Assessment

    Science.gov (United States)

    Kenney, Melissa A.; Chen, Robert; Baptista, Sandra R.; Quattrochi, Dale; O'Brien, Sheila

    2011-01-01

    The National Climate Assessment (NCA) is being conducted under the auspices of the U.S. Global Change Research Program (USGCRP), pursuant to the Global Change Research Act of 1990, Section 106, which requires a report to Congress every 4 years. The current NCA (http://globalchange.gov/what-we-do/assessment/) differs in multiple ways from previous U.S. climate assessment efforts, being: (1) more focused on supporting the Nation s activities in adaptation and mitigation and on evaluating the current state of scientific knowledge relative to climate impacts and trends; (2) a long-term, consistent process for evaluation of climate risks and opportunities and providing information to support decision-making processes within regions and sectors; and (3) establishing a permanent assessment capacity both inside and outside of the federal government. As a part of ongoing, long-term assessment activities, the NCA intends to develop an integrated strategic framework and deploy climate-relevant physical, ecological, and societal indicators. The NCA indicators framework is underdevelopment by the NCA Development and Advisory Committee Indicators Working Group and are envisioned as a relatively small number of policy-relevant integrated indicators designed to provide a consistent, objective, and transparent overview of major variations in climate impacts, vulnerabilities, adaptation, and mitigation activities across sectors, regions, and timeframes. The potential questions that could be addressed by these indicators include: How do we know that there is a changing climate and how is it expected to change in the future? Are important climate impacts and opportunities occurring or predicted to occur in the future? Are we adapting successfully? What are the vulnerabilities and resiliencies given a changing climate? Are we preparing adequately for extreme events? It is not expected that the NCA societal indicators would be linked directly to a single decision or portfolio of

  12. Physics at the proposed National Underground Science Facility

    International Nuclear Information System (INIS)

    Nieto, M.M.

    1983-01-01

    The scientific, technical, and financial reasons for building a National Underground Science Facility are discussed. After reviewing examples of other underground facilities, we focus on the Los Alamos proposal and the national for its choice of site

  13. National Survey of Yoga Practitioners: Mental and Physical Health Benefits

    Science.gov (United States)

    Ross, Alyson; Friedmann, Erika; Bevans, Margaret; Thomas, Sue

    2013-01-01

    Summary Objectives to describe yoga practice and health characteristics of individuals who practice yoga, and to explore their beliefs regarding the effects of their yoga practice on their health. Design a cross-sectional design with anonymous online surveys Setting 4307 randomly selected individuals from 15 US Iyengar yoga studios (n = 18,160), representing 41 states; 1087 individuals responded, with 1045 (24.3%) surveys completed. Outcome Measures Freiberg Mindfulness Inventory, Mental Health Continuum (subjective well-being), Multi-factor Screener (diet), PROMIS sleep disturbance, fatigue, and social support, International Physical Activity Questionnaire. Results Age: 19 to 87 years (M = 51.7 ± 11.7), 84.2% female, 89.2% white, 87.4% well educated (≥ bachelor’s degree). Mean years of yoga practice = 11.4 (± 7.5). BMI = 12.1–49.4 (M = 23.1 ± 3.9). Levels of obesity (4.9%), smoking (2%), and fruit and vegetable consumption (M = 6.1 ± 1.1) were favorable compared to national norms. 60% reported at least one chronic/serious health condition, yet most reported very good (46.3%) or excellent (38.8%) general health. Despite high levels of depression (24.8 %), nearly all were moderately mentally healthy (55.2%) or flourishing (43.8%). Participants agreed yoga improved: energy (84.5%), happiness (86.5%), social relationships (67%), sleep (68.5%), and weight (57.3%), and beliefs did not differ substantially according to race or gender. The more they practiced yoga, whether in years or in amount of class or home practice, the higher their odds of believing yoga improved their health. Conclusions Individuals who practice yoga are not free of health concerns, but most believe their health improved because of yoga. Yoga might be beneficial for a number of populations including elderly women and those with chronic health conditions. PMID:23876562

  14. Magnetic excitations in ferromagnetic semiconductors

    International Nuclear Information System (INIS)

    Furdyna, J.K.; Liu, X.; Zhou, Y.Y.

    2009-01-01

    Magnetic excitations in a series of GaMnAs ferromagnetic semiconductor films were studied by ferromagnetic resonance (FMR). Using the FMR approach, multi-mode spin wave resonance spectra have been observed, whose analysis provides information on magnetic anisotropy (including surface anisotropy), distribution of magnetization precession within the GaMnAs film, dynamic surface spin pinning (derived from surface anisotropy), and the value of exchange stiffness constant D. These studies illustrate a combination of magnetism and semiconductor physics that is unique to magnetic semiconductors

  15. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  16. Abstracts of the 81. national meeting on physics of the Argentine Physics Association (AFA)

    International Nuclear Information System (INIS)

    1996-01-01

    Abstracts are presented at the 81 Annual meeting of the Argentine Physics Association (AFA). The papers can be grouped under the following main topics: teaching, history and philosophy of physics; classical and quantum physics: particles and fields; statistical physics and thermodynamics; nuclear physics; atomic and molecular physics; optic; fluid dynamics and plasmas; condensed matter; instrumentation; geophysics and astrophysics. refs., ills

  17. Wake fields in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1994-05-01

    It is shown that an intense short laser pulse propagating through a semiconductor plasma will generated longitudinal Langmuir waves in its wake. The measurable wake field can be used as a diagnostic to study nonlinear optical phenomena. For narrow gap semiconductors (for examples InSb) with Kane-type dispersion relation, the system can simulate, at currently available laser powers, the physics underlying wake-field accelerators. (author). 9 refs, 1 fig

  18. Images through semiconductors

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Improved image processing techniques are constantly being developed for television and for scanners using X-rays or other radiation for industrial or medical applications, etc. As Erik Heijne of CERN explains here, particle physics too has its own special requirements for image processing. The increasing use of semiconductor techniques for handling measurements down to the level of a few microns provides another example of the close interplay between scientific research and technological development. (orig.).

  19. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  20. National practices in physical protection of nuclear materials. Regulatory basis

    International Nuclear Information System (INIS)

    Goltsov, V.Y.

    2002-01-01

    Full text: The Federal law 'On The Use Of Atomic Energy' containing the section on physical protection of nuclear materials and nuclear facilities was issued in 1995 in Russian Federation. This document became the first federal level document regulating the general requirements to physical protection (PP). The federal PP rules developed on the base of this law by Minatom of Russia and other federal bodies of the Russian Federation were put in force by the government of Russia in 1997. The requirements of the convention on physical protection of nuclear materials (INFCIRC 274) and the modern IAEA recommendations (INFCIRC/225/Rev.4) are taken into account in the PP rules. Besides, while developing the PP rules the other countries' experience in this sphere has been studied and taken into account. The PP rules are action-obligatory for all juridical persons dealing with nuclear activity and also for those who are coordinating and monitoring this activity. Nuclear activity without physical protection ensured in accordance with PP rules requirements is prohibited. The requirements of PP Rules are stronger than the IAEA recommendations. The PP rules are establishing: physical protection objectives; federal executive bodies and organizations functions an implementation of physical protection; categorization of nuclear materials; requirements for nuclear materials physical protection as during use and storage as during transportation; main goals of state supervision and ministry level control for physical protection; notification order about the facts of unauthorized actions regarding nuclear materials and facilities. Besides the above mentioned documents, there were put in force president decrees, federal laws and regulations in the field of: counteraction to nuclear terrorism; interactions in physical protection systems; military and ministerial on-site guard activities; information protection. By the initiative of Minatom of Russia the corrections were put into the

  1. Physics through the 1990s: condensed-matter physics

    International Nuclear Information System (INIS)

    1986-01-01

    The volume presents the current status of condensed-matter physics from developments since the 1970s to opportunities in the 1990s. Topics include electronic structure, vibrational properties, critical phenomena and phase transitions, magnetism, semiconductors, defects and diffusion, surfaces and interfaces, low-temperature physics, liquid-state physics, polymers, nonlinear dynamics, instabilities, and chaos. Appendices cover the connections between condensed-matter physics and applications of national interest, new experimental techniques and materials, laser spectroscopy, and national facilities for condensed-matter physics research. The needs of the research community regarding support for individual researchers and for national facilities are presented, as are recommendations for improved government-academic-industrial relations

  2. Conductors, semiconductors, superconductors. A compact introduction to history, development, and theory of solid-state physics. 2. ed.

    International Nuclear Information System (INIS)

    Huebener, Rudolf

    2017-01-01

    The present book is a strongly revised and supplemented edition of the title: ''Kristalle: Spiefeld der Elektronen'', published scarcely ten years ago by the same author. Especially the physical contents are explained by the mathematically formulated foundations. The book appeals to students of natural sciences and especially of physics as well as to engineers as introduction to the wide field of solid-state physics, so to speak as motivating prestage to the established and very extensive textbooks. Beside the physical contents the book treats the important role of numerous important and often still very young scientists. By corresponding supplements in this book it is tried to present the fundamental developments in their wide environment.

  3. The National Cancer Institute's Physical Sciences - Oncology Network

    Science.gov (United States)

    Espey, Michael Graham

    In 2009, the NCI launched the Physical Sciences - Oncology Centers (PS-OC) initiative with 12 Centers (U54) funded through 2014. The current phase of the Program includes U54 funded Centers with the added feature of soliciting new Physical Science - Oncology Projects (PS-OP) U01 grant applications through 2017; see NCI PAR-15-021. The PS-OPs, individually and along with other PS-OPs and the Physical Sciences-Oncology Centers (PS-OCs), comprise the Physical Sciences-Oncology Network (PS-ON). The foundation of the Physical Sciences-Oncology initiative is a high-risk, high-reward program that promotes a `physical sciences perspective' of cancer and fosters the convergence of physical science and cancer research by forming transdisciplinary teams of physical scientists (e.g., physicists, mathematicians, chemists, engineers, computer scientists) and cancer researchers (e.g., cancer biologists, oncologists, pathologists) who work closely together to advance our understanding of cancer. The collaborative PS-ON structure catalyzes transformative science through increased exchange of people, ideas, and approaches. PS-ON resources are leveraged to fund Trans-Network pilot projects to enable synergy and cross-testing of experimental and/or theoretical concepts. This session will include a brief PS-ON overview followed by a strategic discussion with the APS community to exchange perspectives on the progression of trans-disciplinary physical sciences in cancer research.

  4. Physical Fitness Profiles of Sitting Volleyball Players of the Turkish National Team

    Science.gov (United States)

    Yüksel, Mehmet Fatih; Sevindi, Tarik

    2018-01-01

    This research is conducted to determine the physical profiles of sitting volleyball players of the Turkish National Team. 12 male players from Turkish Sitting Volleyball National Team volunteered to participate in the study. The anthropometric measurements were taken over dominant extremity. In order to determine the physical features of the…

  5. 3 CFR 8370 - Proclamation 8370 of May 1, 2009. National Physical Fitness and Sports Month, 2009

    Science.gov (United States)

    2010-01-01

    ... Fitness and Sports Month, 2009 8370 Proclamation 8370 Presidential Documents Proclamations Proclamation 8370 of May 1, 2009 Proc. 8370 National Physical Fitness and Sports Month, 2009By the President of the... Council on Physical Fitness and Sports sponsors the National President’s Challenge, a six-week competition...

  6. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1982-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices in which the device is rapidly heated to a temperature between 450 and 900 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. (author)

  7. Proceedings of the 5. National Meeting on Intermediate Energy Physics

    International Nuclear Information System (INIS)

    1984-05-01

    Several papers concerning the physics at intermediate energies (∼ 100-1000MeV) are presented in this proceedings. Almost all the works show overlapping between Nuclear and Particles Physics. There is a predominance in theoretical papers. (L.C.) [pt

  8. 75 FR 24365 - National Physical Fitness and Sports Month, 2010

    Science.gov (United States)

    2010-05-05

    ..., fair play, focus, and dedication. As they develop into athletes, they acquire time management, goal... Physical Fitness and Sports Month, 2010 By the President of the United States of America A Proclamation The... improve their mental and physical wellbeing. This month, we celebrate fitness, sports, and outdoor...

  9. Proceedings of the 6. National Meeting on Intermediate Energy Physics

    International Nuclear Information System (INIS)

    1986-01-01

    Several works on nuclear, hadron and quark physics are presented covering both aspects; theoretical and experimental, are presented. Emphasis is given in the intermediate energy region, several MeV centil few GeV. (L.C.) [pt

  10. Sandia National Laboratories: Physical, Chemical, and Nano Sciences

    Science.gov (United States)

    Involvement Contribution Programs Volunteer Programs Education Programs Environmental Responsibility Involvement News News Releases Media Contacts & Resources Lab News Image Gallery Publications Annual for the mission needs of our parent agency, the National Nuclear Security Administration (NNSA), with

  11. Nutrition, Physical Activity, and Obesity - National Immunization Survey (Breastfeeding)

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset includes breastfeeding data from the National Immunization Survey (NIS). This data is used for DNPAO's Data, Trends, and Maps database, which provides...

  12. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  13. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1981-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices is described in which the device is rapidly heated to a temperature between 450 and 600 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. The process may be enhanced by the application of optical radiation from a Xenon lamp. (author)

  14. The Computational Physics Program of the national MFE Computer Center

    International Nuclear Information System (INIS)

    Mirin, A.A.

    1989-01-01

    Since June 1974, the MFE Computer Center has been engaged in a significant computational physics effort. The principal objective of the Computational Physics Group is to develop advanced numerical models for the investigation of plasma phenomena and the simulation of present and future magnetic confinement devices. Another major objective of the group is to develop efficient algorithms and programming techniques for current and future generations of supercomputers. The Computational Physics Group has been involved in several areas of fusion research. One main area is the application of Fokker-Planck/quasilinear codes to tokamaks. Another major area is the investigation of resistive magnetohydrodynamics in three dimensions, with applications to tokamaks and compact toroids. A third area is the investigation of kinetic instabilities using a 3-D particle code; this work is often coupled with the task of numerically generating equilibria which model experimental devices. Ways to apply statistical closure approximations to study tokamak-edge plasma turbulence have been under examination, with the hope of being able to explain anomalous transport. Also, we are collaborating in an international effort to evaluate fully three-dimensional linear stability of toroidal devices. In addition to these computational physics studies, the group has developed a number of linear systems solvers for general classes of physics problems and has been making a major effort at ascertaining how to efficiently utilize multiprocessor computers. A summary of these programs are included in this paper. 6 tabs

  15. Particle Physics and Astronomy Research Council (PPARC) members, United Kingdom, visiting the ATLAS semiconductor tracker (SCT) module tests.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Photo 01: Mr Peter Warry, PPARC Chairman, Victrex Plc, United Kingdom visiting the ATLAS SCT module tests with Dr Joleen Pater, SCT (Manchester). Photo 02: PPARC Council Members, United Kingdom, visiting the ATLAS SCT module tests. L.t to r.: Mrs Judith Scott, Chief Executive, British Computer Society, Prof. George Efstathiou, Institute of Astronomy, University of Cambridge, Mr Peter Warry, PPARC Chairman, Victrex Plc, Prof. Martin Ward, Director X-Ray Astronomy, of Leicester, Prof. James Stirling, Director, Institute for Particle Physics Phenomenology, University of Durham and Prof. Brian Foster, University of Bristol.

  16. Computational-physics program of the National MFE Computer Center

    International Nuclear Information System (INIS)

    Mirin, A.A.

    1982-02-01

    The computational physics group is ivolved in several areas of fusion research. One main area is the application of multidimensional Fokker-Planck, transport and combined Fokker-Planck/transport codes to both toroidal and mirror devices. Another major area is the investigation of linear and nonlinear resistive magnetohydrodynamics in two and three dimensions, with applications to all types of fusion devices. The MHD work is often coupled with the task of numerically generating equilibria which model experimental devices. In addition to these computational physics studies, investigations of more efficient numerical algorithms are being carried out

  17. Magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bihler, Christoph

    2009-04-15

    In this thesis we investigated in detail the properties of Ga{sub 1-x}Mn{sub x}As, Ga{sub 1-x}Mn{sub x}P, and Ga{sub 1-x}Mn{sub x}N dilute magnetic semiconductor thin films with a focus on the magnetic anisotropy and the changes of their properties upon hydrogenation. We applied two complementary spectroscopic techniques to address the position of H in magnetic semiconductors: (i) Electron paramagnetic resonance, which provides direct information on the symmetry of the crystal field of the Mn{sup 2+} atoms and (ii) x-ray absorption fine structure analysis which allows to probe the local crystallographic neighborhood of the absorbing Mn atom via analysing the fine structure at the Mn K absorption edge. Finally, we discussed the obstacles that have to be overcome to achieve Curie temperatures above the current maximum in Ga{sub 1-x}Mn{sub x}As of 185 K. Here, we outlined in detail the generic problem of the formation of precipitates at the example of Ge:MN. (orig.)

  18. research proposal to the national accelerator centre: physical ...

    African Journals Online (AJOL)

    COWLEY

    the study by Moussa however differ from this study since building material was .... The efficiency calibrations measurements of the system were done at a standard ..... underlying geochemical and -physical principles”. ... sites – a case study from East Sinai, Egypt”. ... “A new high background radiation area in the geothermal.

  19. National platforms for evidence-informed physical activity policy making

    DEFF Research Database (Denmark)

    Rus, Diana; Bozdog, Elena; Loncarevic, Natasa

    Evidence-informed policy making in physical activity calls for inter-sectoral and interdisciplinary collaboration. To facilitate the exchange of knowledge, experiences and ideas across practice, policy and research, as part of the REPOPA Project and dissemination work, it was encouraged...

  20. The computational physics program of the National MFE Computer Center

    International Nuclear Information System (INIS)

    Mirin, A.A.

    1988-01-01

    The principal objective of the Computational Physics Group is to develop advanced numerical models for the investigation of plasma phenomena and the simulation of present and future magnetic confinement devices. Another major objective of the group is to develop efficient algorithms and programming techniques for current and future generation of supercomputers. The computational physics group is involved in several areas of fusion research. One main area is the application of Fokker-Planck/quasilinear codes to tokamaks. Another major area is the investigation of resistive magnetohydrodynamics in three dimensions, with applications to compact toroids. Another major area is the investigation of kinetic instabilities using a 3-D particle code. This work is often coupled with the task of numerically generating equilibria which model experimental devices. Ways to apply statistical closure approximations to study tokamak-edge plasma turbulence are being examined. In addition to these computational physics studies, the group has developed a number of linear systems solvers for general classes of physics problems and has been making a major effort at ascertaining how to efficiently utilize multiprocessor computers

  1. Computational Physics Program of the National MFE Computer Center

    International Nuclear Information System (INIS)

    Mirin, A.A.

    1984-12-01

    The principal objective of the computational physics group is to develop advanced numerical models for the investigation of plasma phenomena and the simulation of present and future magnetic confinement devices. A summary of the groups activities is presented, including computational studies in MHD equilibria and stability, plasma transport, Fokker-Planck, and efficient numerical and programming algorithms. References are included

  2. Oak Ridge Reservation. Physical Characteristics and National Resources

    Energy Technology Data Exchange (ETDEWEB)

    Parr, Patricia Dreyer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Joan, F. Hughes [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2006-10-09

    The topology, geology, hydrology, vegetation, and wildlife of the Oak Ridge Reservation (ORR) provide a complex and intricate array of resources that directly impact land stewardship and use decisions. The purpose of this document is to consolidate general information regarding the natural resources and physical characteristics of the ORR.

  3. Physical characteristics modification of a SiGe-HBT semiconductor device for performance improvement in a terahertz detecting system

    Science.gov (United States)

    Ghodsi, Hamed; Kaatuzian, Hassan

    2015-05-01

    In order to improve the performance of a pre-designed direct conversion terahertz detector which is implemented in a 0.25 μm-SiGe-BiCMOS process, we propose some slight modifications in the bipolar section of the SiGe device physical design. Comparison of our new proposed device and the previously reported device is done by SILVACO TCAD software simulation and we have used previous experimentally reported data to confirm our software simulations. Our proposed modifications in device structural design show a present device responsivity improvement of about 10% from 1 to 1.1 A/W while the bandwidth improvement is about 218 GHz. The minimum noise equivalent power at detector output is increased by about 14.3% and finally power consumption per pixel at the maximum responsivity is decreased by about 5%.

  4. Physical characteristics modification of a SiGe-HBT semiconductor device for performance improvement in a terahertz detecting system

    International Nuclear Information System (INIS)

    Ghodsi, Hamed; Kaatuzian, Hassan

    2015-01-01

    In order to improve the performance of a pre-designed direct conversion terahertz detector which is implemented in a 0.25 μm-SiGe-BiCMOS process, we propose some slight modifications in the bipolar section of the SiGe device physical design. Comparison of our new proposed device and the previously reported device is done by SILVACO TCAD software simulation and we have used previous experimentally reported data to confirm our software simulations. Our proposed modifications in device structural design show a present device responsivity improvement of about 10% from 1 to 1.1 A/W while the bandwidth improvement is about 218 GHz. The minimum noise equivalent power at detector output is increased by about 14.3% and finally power consumption per pixel at the maximum responsivity is decreased by about 5%. (paper)

  5. Physical properties of Fe doped In_2O_3 magnetic semiconductor annealed in hydrogen at different temperature

    International Nuclear Information System (INIS)

    Baqiah, H.; Ibrahim, N.B.; Halim, S.A.; Chen, S.K.; Lim, K.P.; Kechik, M.M. Awang

    2016-01-01

    The effects of hydrogen-annealing at different temperatures (300, 400, 500 and 600 °C) on physical properties of In_2_−_xFe_xO_3 (x=0.025) thin film were investigated. The structural measurement using XRD shows that the film has a single In_2O_3 phase structure when annealed in hydrogen at 300–500 °C, however when annealed in hydrogen at 600 °C the film has a mixed phase structure of In_2O_3 and In phases. The electrical measurements show that the carrier concentrations of the films decrease with the increase of hydrogen-annealing temperature in the range 300–500 °C. The optical band gap of the films decreases with increasing hydrogen-annealing temperatures. The saturation magnetisation, Ms, and coercivity of films increase with the increment of hydrogen annealing temperature. The film annealed at 300 °C has the lowest resistivity, ρ=0.03 Ω cm, and the highest carrier concentrations, n=6.8×10"1"9 cm"−"3, while film annealed at 500 °C has both good electrical (ρ=0.05 Ω.cm and n=2.2×10"1"9 cm"−"3) and magnetic properties, Ms=21 emu/cm"-"3. - Highlights: • Physical properties of films were sensitive to hydrogen-annealing temperature. • Magnetisation, Ms, of films increased with increase of hydrogen annealing temperature. • Film annealed in hydrogen at 300 °C has the lowest resistivity, ρ=0.03 Ω cm. • Film annealed in hydrogen at 600 °C has highest magnetisation, Ms=30 emu/cm"3.

  6. Self-reported physical activity among blacks: estimates from national surveys.

    Science.gov (United States)

    Whitt-Glover, Melicia C; Taylor, Wendell C; Heath, Gregory W; Macera, Caroline A

    2007-11-01

    National surveillance data provide population-level estimates of physical activity participation, but generally do not include detailed subgroup analyses, which could provide a better understanding of physical activity among subgroups. This paper presents a descriptive analysis of self-reported regular physical activity among black adults using data from the 2003 Behavioral Risk Factor Surveillance System (n=19,189), the 2004 National Health Interview Survey (n=4263), and the 1999-2004 National Health and Nutrition Examination Survey (n=3407). Analyses were conducted between January and March 2006. Datasets were analyzed separately to estimate the proportion of black adults meeting national physical activity recommendations overall and stratified by gender and other demographic subgroups. The proportion of black adults reporting regular PA ranged from 24% to 36%. Regular physical activity was highest among men; younger age groups; highest education and income groups; those who were employed and married; overweight, but not obese, men; and normal-weight women. This pattern was consistent across surveys. The observed physical activity patterns were consistent with national trends. The data suggest that older black adults and those with low education and income levels are at greatest risk for inactive lifestyles and may require additional attention in efforts to increase physical activity in black adults. The variability across datasets reinforces the need for objective measures in national surveys.

  7. Semiconductor Laser Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  8. Physics teachers' perspectives on High School national curriculum policies

    Directory of Open Access Journals (Sweden)

    Gleice Ferraz

    2014-04-01

    Full Text Available This study aimed to identify, in the context of an activity developed in online course for continuing education and from the theoretical approach of Mikhail Bakhtin, the discursive appropriation of PCNEM by high school physics teachers who work in different regional realities. The analysis indicated a positive perspective by teachers related to PCNEM, in addition to full accordance with the main path indicated by the legislation: the contextualized teaching. Despite the differences between educational regions we could not identify explicit signs of how these differences impacted the appropriation of terms found in PCNEM. The silence of teachers in relation to non-methodological aspects of physics teaching shapes their perspectives and also emphasizes the concern for didactic transposition of the content required by the curriculum, leaving out the question of why we have this curriculum and not other.

  9. KEK (National Laboratory for High Energy Physics) annual report, 1988

    International Nuclear Information System (INIS)

    1989-01-01

    Throughout this year, TRISTAN has maintained the highest energy among the electron-positron colliders in the world. After operating at 57 GeV in the center of mass with full operation of the APS-type room temperature RF accelerating system, 16 units of 5-cell superconducting RF cavities 24 m in total length were installed in the Nikko straight section during the summer shutdown. As a result, 30.4 GeV/beam or 60.8 GeV in the center of mass was achieved beyond the original design energy goal of TRISTAN. All experimental collaborations at the four intersections have collected much interesting data in the new energy region of electron-positron collisions. The experiment SHIP, a search for highly ionizing particles, has completed data taking in the Nikko experimental hall and is going to give new limits on Dirac monopoles. At the 24th International Conference on High Energy Physics held at Munich in August, 1988, as CERN Courier's report, for instance, the results from TRISTAN were really the highlight in e + e - collision physics. Although we could not find any definite evidence for the existence of toponium under 60 GeV or other new particles under 56 GeV, we obtained much new physics concerning interfering effects between electromagnetic and weak interactions, new information about QCD and so on. Active experiments on hadron physics with the 12 GeV main ring also have been carried out. For instance, an internal gas target experiment with a polarized proton beam was performed by a group from Texas A and M University in cooperation with a Japanese group. The KEK PS is now a very unique proton machine in the 10 GeV energy region as well as Brookhaven's AGS. (J.P.N.)

  10. Metallurgy and purification of semiconductor materials

    International Nuclear Information System (INIS)

    Mughal, G.R.; Ali, M.M.; Ali, I.

    1996-01-01

    In this article the metallurgical aspects of semiconductor science and technology have been stressed here rather than of the physical and electronic aspect of the subject. Semiconductor technology has not merely presented the metallurgist with new challenges. The ease with which the semiconductor planes cleave make possible, the preparation and study of virgin surface. Semiconductor materials were being widely employed in the study of sub-boundaries and structures and can largely contribute to the study of certain aspects of nucleation and growth, precipitation phenomena, mechanical behaviour, in metallurgy. (A.B.)

  11. A case for physical education / life orientation : the health of a nation ...

    African Journals Online (AJOL)

    South African Journal for Research in Sport, Physical Education and Recreation ... in obesity among the youth, Europe, Australia and Canada do not seem to lag behind. ... initiatives at school, local community, national and international levels.

  12. Nuclear physics and heavy element research at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Stoyer, Mark A; Ahle, L E; Becker, J A; Bernshein, L A; Bleuel, D L; Burke, J T; Dashdorj, D; Henderson, R A; Hurst, A M; Kenneally, Jacqueline M; Lesher, S R; Moody, K J; Nelson, S L; Norman, E B; Pedretti, M; Scielzo, N D; Shaughnessy, D A; Sheets, S A; Stoeffl, W; Stoyer, N J [Lawrence Livermore National Laboratory, University of California, Livermore (United States)

    2009-12-31

    This paper highlights some of the current basic nuclear physics research at Lawrence Livermore National Laboratory (LLNL). The work at LLNL concentrates on investigating nuclei at the extremes. The Experimental Nuclear Physics Group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

  13. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  14. Basic properties of semiconductors

    CERN Document Server

    Landsberg, PT

    2013-01-01

    Since Volume 1 was published in 1982, the centres of interest in the basic physics of semiconductors have shifted. Volume 1 was called Band Theory and Transport Properties in the first edition, but the subject has broadened to such an extent that Basic Properties is now a more suitable title. Seven chapters have been rewritten by the original authors. However, twelve chapters are essentially new, with the bulk of this work being devoted to important current topics which give this volume an almost encyclopaedic form. The first three chapters discuss various aspects of modern band theory and the

  15. Getting Women Into the Physics Leadership Structure Nationally and Internationally

    Science.gov (United States)

    Williams, Elvira S.; Diaz, Lilliam Alvarez; Gebbie, Katharine B.; El-Sayed, Karimat

    2005-10-01

    The underrepresentation of women among physicists around the world, especially in leadership positions, has broad implications for industries and government agencies with a strong need for a technologically educated workforce. The dearth of women physicists in academia exacerbates the situation in that female students lack exposure to successful women in the field. Three years ago, an international group of women met for a round table discussion at the First IUPAP International Conference on Women in Physics and discussed the importance of having women in leadership positions. They shared their experiences and successes, and drew up and reported a set of recommendations addressing the preparation of women for leadership, the selection process, and the responsibilities of institutions. They acknowledged that implementation of their recommendations would differ among countries. At the Second IUPAP International Conference on Women in Physics an international group of women met again to review, revise, and move forward on revamped recommendations from the first conference. This is a report on the new set of revamped recommendations, which address why women should be in leadership positions, goal setting, best practices, commitments, and follow-up actions for the attendees of the second conference.

  16. The European physical and rehabilitation medicine journal network: historical notes on national journals.

    Science.gov (United States)

    Negrini, S; Ilieva, E; Moslavac, S; Zampolini, M; Giustini, A

    2010-06-01

    In the last 40 years, physical and rehabilitation medicine (PRM) has made significant steps forward in Europe with the foundation of the European Federation of Physical Medicine and Rehabilitation (EFPMR) (1963) which gave rise to the European Society of Physical and Rehabilitation Medicine (ESPRM) (2004) the European Academy of Rehabilitation Medicine (1970), the PRM Section of the European Union of Medical Specialists (1974), and the European Board of PRM (1991). Our journal, formerly Europa Medico-physica (1964), the official journal of the EFPMR, now European Journal of Physical and Rehabilitation Medicine (EJPRM) and official journal of the ESPRM since 2008, is distinct for its steadfast European vocation, long-standing Mediter-ranean interests and connections with various national scientific societies. Jointly with the ESPRM, efforts are under way to set up the European Physical and Rehabilitation Medicine Journal Network (EPRMJN). The aim of this article is to present a profile of the national journals in the EPRMJN so as to give a better overview of how the scientific part of PRM in Europe has developed within a national perspective. A profile of the following national journals is presented: Annals of Physical and Rehabilitation Medicine (France), Fizikalna i rehabilitacijska medicina (Physical and Rehabilitation Medicine) (Croatia), Neurorehabilitation (Bulgaria), Physical and Rehabilitation Medicine Portuguese Society Journal (Portugal), Physical Medicine, Rehabilitaton, Health (Bulgaria), Physikalische Medizin - Rehabilitationsmedizin - Kurort-medizin/Journal of Physical and Rehabilitation Medicine (Germany and Austria) Prevention and Rehabilitation (Bulgaria), Rehabilitacija (Rehabilitation) (Slovenia), Rehabilitación (Madr) (Spain), Turkish Journal of Physical Medicine and Rehabilitation (Turkey). Some national journals in Europe have a very long history and tradition of research and education. Having a better knowledge of these realities, usually

  17. The National Physical Education Standards and Grade-Level Outcomes: The Future of Elementary Physical Education

    Science.gov (United States)

    Holt/Hale, Shirley Ann; Persse, Dan

    2015-01-01

    It is during the early educational years that skills are developed, habits are formed, and values are shaped. The skills for a lifetime of physical activity are developed through quality teaching, deliberate practice, assessment and reflection. Research supports the importance of elementary physical education experiences and the importance of…

  18. National Institute of Nuclear and Particle Physics - IN2P3. 2001-2003 activity report

    International Nuclear Information System (INIS)

    Spiro, Michel; Armand, Dominique

    2005-12-01

    The CNRS National Institute of Nuclear and Particle Physics (IN2P3) acts as national leader and coordinator in the fields of nuclear, particle and astro-particle physics, technological advances and their related applications, especially in the health and energy sectors. This research aims to explore particle and nuclear physics, fundamental interactions, and the links between the infinitely small and the infinitely large. Scientific fields include: Particle physics and hadronic physics, Nuclear physics, Astro-particles and cosmology, Neutrinos, Instrumentation, Computing and data, Research and development of accelerators, Back-end of the nuclear fuel cycle and nuclear energy, Medical applications. This document is IN2P3's activity report for the 2001-2003 period. It presents the strategic priorities of the Institute, the highlights and projects of the period

  19. Proceedings of the Third National Conference on Nuclear Physics and Techniques

    International Nuclear Information System (INIS)

    Nguyen Thanh Binh; Nguyen Nhi Dien; Tran Kim Hung; Vuong Huu Tan

    2000-01-01

    The proceedings contains 130 papers of scientists from institutes, universities, enterprises nation-wide in Vietnam. Its subjects include: nuclear physics, theoretical physics, science and technology of nuclear reactor, application of nuclear techniques in industry, agriculture, biology, medicine, geo-hydrology, environmental protection, nuclear equipment, radiation technology, material technology, waste management, ect

  20. Proceedings of the 6. National Meeting of Reactor Physics and Thermohydraulic

    International Nuclear Information System (INIS)

    1986-01-01

    The proceedings of the 6. National Meeting of Reactor Physics and Thermohydraulic - 6. ENFIR - allow to evaluate the present status of development in reactor physics and thermohydraulic fields. The mathematical models and methods for calculating neutronic of nuclear reactors, safety reactor analysis, measuring methods of neutronic parameters, computerized simulation of accidents, transients and thermohydraulic analysis are presented. (M.C.K.) [pt

  1. Sexuality and Physical Contact in National Social Life, Health, and Aging Project Wave 2

    OpenAIRE

    Adena M. Galinsky; Martha K. McClintock; Linda J. Waite

    2014-01-01

    Introduction. Wave 2 of the National Social Life, Health, and Aging Project (NSHAP) includes new measures of sexual interest and behavior, as well as new measures of the context of sexual experience and the frequency and appeal of physical contact. This is the first time many of these constructs have been measured in a nationally representative sample.

  2. Towards filament free semiconductor lasers

    DEFF Research Database (Denmark)

    McInerney, John; O'Brien, Peter; Skovgaard, Peter M. W.

    2000-01-01

    We outline physical models and simulations for suppression of self-focusing and filamentation in large aperture semiconductor lasers. The principal technical objective is to generate multi-watt CW or quasi-CW outputs with nearly diffraction limited beams, suitable for long distance free space...... propagation structures in lasers and amplifiers which suppress lateral reflections....

  3. Semiconductor laser shearing interferometer

    International Nuclear Information System (INIS)

    Ming Hai; Li Ming; Chen Nong; Xie Jiaping

    1988-03-01

    The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

  4. KEK (National Laboratory for High Energy Physics) annual report, 1993

    International Nuclear Information System (INIS)

    1994-01-01

    The scientific activity of KEK remained strong in 1993, its coverage of scientific fields expanded, the understanding in each field deepened, thus it is believed that KEK is on the right track towards the ideal interdisciplinary and international scientific laboratory. The construction of the B-factory in KEK was approved by the government. Tremendous technical progress was made towards the e + e - collider which will be one of the last machines needed for understanding the fundamental structures of matters. To strengthen the interdisciplinary character of the laboratory, the R and D works towards the construction of Japanese Hadron Project were advanced. This project will provide an intense pulsed neutron source, and supply the intense beam of unstable nuclei. In the Photon Factory, a huge number of experiments have been performed. To strengthen the research activities, the reforming will start for the injection linac and the 2.5 GeV storage ring. In this report, the activities of Accelerator Department and Physics Department, international collaboration, the circumstances of engineering research and scientific support centers, booster synchrotron utilization facility and the Photon Factory and described. (K.I.)

  5. Analysis of the national common curriculum basis and physical education in focus

    Directory of Open Access Journals (Sweden)

    Laine Rocha Moreira

    2016-09-01

    Full Text Available This article analyzes the manuscript of the National Common Curriculum Basis and it comprehends the conception of Physical Education. It identifies the concept attributed to physical education by the National Common Curriculum Basis. Methodologically, it uses a bibliographic and documentary analysis (National Common Curriculum Basis, the dialectic as method and applying content analysis to process data. It verifies that the National Common Curriculum Basis identifies the physical education in the language field and it affiliates to an eclecticism regarding to their conception and specific body of knowledge, generating inconsistency in content and the formative processes of this knowledge field. It concludes that the manuscript materializes an alliance between education and capital, defending the central hierarchical groups’ interests, transforming the right to education in marketing service.

  6. Progress in hohlraum physics for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Moody, J. D., E-mail: moody4@llnl.gov; Callahan, D. A.; Hinkel, D. E.; Amendt, P. A.; Baker, K. L.; Bradley, D.; Celliers, P. M.; Dewald, E. L.; Divol, L.; Döppner, T.; Eder, D. C.; Edwards, M. J.; Jones, O.; Haan, S. W.; Ho, D.; Hopkins, L. B.; Izumi, N.; Kalantar, D.; Kauffman, R. L.; Kilkenny, J. D. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); and others

    2014-05-15

    Advances in hohlraums for inertial confinement fusion at the National Ignition Facility (NIF) were made this past year in hohlraum efficiency, dynamic shape control, and hot electron and x-ray preheat control. Recent experiments are exploring hohlraum behavior over a large landscape of parameters by changing the hohlraum shape, gas-fill, and laser pulse. Radiation hydrodynamic modeling, which uses measured backscatter, shows that gas-filled hohlraums utilize between 60% and 75% of the laser power to match the measured bang-time, whereas near-vacuum hohlraums utilize 98%. Experiments seem to be pointing to deficiencies in the hohlraum (instead of capsule) modeling to explain most of the inefficiency in gas-filled targets. Experiments have begun quantifying the Cross Beam Energy Transfer (CBET) rate at several points in time for hohlraum experiments that utilize CBET for implosion symmetry. These measurements will allow better control of the dynamic implosion symmetry for these targets. New techniques are being developed to measure the hot electron energy and energy spectra generated at both early and late time. Rugby hohlraums offer a target which requires little to no CBET and may be less vulnerable to undesirable dynamic symmetry “swings.” A method for detecting the effect of the energetic electrons on the fuel offers a direct measure of the hot electron effects as well as a means to test energetic electron mitigation methods. At higher hohlraum radiation temperatures (including near vacuum hohlraums), the increased hard x-rays (1.8–4 keV) may pose an x-ray preheat problem. Future experiments will explore controlling these x-rays with advanced wall materials.

  7. Organic semiconductors in sensor applications

    CERN Document Server

    Malliaras, George; Owens, Róisín

    2008-01-01

    Organic semiconductors offer unique characteristics such as tunability of electronic properties via chemical synthesis, compatibility with mechanically flexible substrates, low-cost manufacturing, and facile integration with chemical and biological functionalities. These characteristics have prompted the application of organic semiconductors and their devices in physical, chemical, and biological sensors. This book covers this rapidly emerging field by discussing both optical and electrical sensor concepts. Novel transducers based on organic light-emitting diodes and organic thin-film transistors, as well as systems-on-a-chip architectures are presented. Functionalization techniques to enhance specificity are outlined, and models for the sensor response are described.

  8. Introduction to semiconductor manufacturing technology

    CERN Document Server

    2012-01-01

    IC chip manufacturing processes, such as photolithography, etch, CVD, PVD, CMP, ion implantation, RTP, inspection, and metrology, are complex methods that draw upon many disciplines. [i]Introduction to Semiconductor Manufacturing Technologies, Second Edition[/i] thoroughly describes the complicated processes with minimal mathematics, chemistry, and physics; it covers advanced concepts while keeping the contents accessible to readers without advanced degrees. Designed as a textbook for college students, this book provides a realistic picture of the semiconductor industry and an in-depth discuss

  9. Semiconductor lasers and herterojunction leds

    CERN Document Server

    Kressel, Henry

    2012-01-01

    Semiconductor Lasers and Heterojunction LEDs presents an introduction to the subject of semiconductor lasers and heterojunction LEDs. The book reviews relevant basic solid-state and electromagnetic principles; the relevant concepts in solid state physics; and the p-n junctions and heterojunctions. The text also describes stimulated emission and gain; the relevant concepts in electromagnetic field theory; and the modes in laser structures. The relation between electrical and optical properties of laser diodes; epitaxial technology; binary III-V compounds; and diode fabrication are also consider

  10. Semiconductor research capabilities at the Lawrence Berkeley Laboratory

    International Nuclear Information System (INIS)

    1987-02-01

    This document discusses semiconductor research capabilities (advanced materials, processing, packaging) and national user facilities (electron microscopy, heavy-ion accelerators, advanced light source)

  11. PREFACE: 1st International Workshop on Theoretical and Computational Physics: Condensed Matter, Soft Matter and Materials Physics & 38th National Conference on Theoretical Physics

    Science.gov (United States)

    2014-09-01

    This volume contains selected papers presented at the 38th National Conference on Theoretical Physics (NCTP-38) and the 1st International Workshop on Theoretical and Computational Physics: Condensed Matter, Soft Matter and Materials Physics (IWTCP-1). Both the conference and the workshop were held from 29 July to 1 August 2013 in Pullman hotel, Da Nang, Vietnam. The IWTCP-1 was a new activity of the Vietnamese Theoretical Physics Society (VTPS) organized in association with the 38th National Conference on Theoretical Physics (NCTP-38), the most well-known annual scientific forum dedicated to the dissemination of the latest development in the field of theoretical physics within the country. The IWTCP-1 was also an External Activity of the Asia Pacific Center for Theoretical Physics (APCTP). The overriding goal of the IWTCP is to provide an international forum for scientists and engineers from academia to share ideas, problems and solution relating to the recent advances in theoretical physics as well as in computational physics. The main IWTCP motivation is to foster scientific exchanges between the Vietnamese theoretical and computational physics community and world-wide scientists as well as to promote high-standard level of research and education activities for young physicists in the country. About 110 participants coming from 10 countries participated in the conference and the workshop. 4 invited talks, 18 oral contributions and 46 posters were presented at the conference. In the workshop we had one keynote lecture and 9 invited talks presented by international experts in the fields of theoretical and computational physics, together with 14 oral and 33 poster contributions. The proceedings were edited by Nguyen Tri Lan, Trinh Xuan Hoang, and Nguyen Ai Viet. We would like to thank all invited speakers, participants and sponsors for making the conference and the workshop successful. Nguyen Ai Viet Chair of NCTP-38 and IWTCP-1

  12. Semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Marstein Erik Stensrud

    2003-07-01

    This thesis presents a study of two material systems containing semiconductor nanocrystals, namely porous silicon (PSi) films and germanium (Ge) nanocrystals embedded in silicon dioxide (SiO2) films. The PSi films were made by anodic etching of silicon (Si) substrates in an electrolyte containing hydrofluoric acid. The PSi films were doped with erbium (Er) using two different doping methods. electrochemical doping and doping by immersing the PSi films in a solution containing Er. The resulting Er concentration profiles were investigated using scanning electron microscopy (SEN1) combined with energy dispersive X-ray analysis (EDS). The main subject of the work on PSi presented in this thesis was investigating and comparing these two doping methods. Ge nanocrystals were made by implanting Ge ions into Si02 films that were subsequently annealed. However. nanocrystal formation occurred only for certain sets of processing parameters. The dependence of the microstructure of the Ge implanted Si02 films on the processing parameters were therefore investigated. A range of methods were employed for these investigations, including transmission electron microscopy (TEM) combined with EDS, X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS). The observed structures, ranging from Ge nanocrystals to voids with diameters of several tens of nanometers and Ge rich Si02 films without any nanocrystals is described. A model explaining the void formation is also presented. For certain sets of processing parameters. An accumulation of Ge at the Si-Si02 interface was observed. The effect of this accumulation on the electrical properties of MOS structures made from Ge implanted SiO2 films was investigated using CV-measurements. (Author)

  13. 2014 Defects in Semiconductors Gordon Research Conference & Gordon Research Seminar. Research Area 1: Materials Science, 1.3 Physical Properties of Materials

    Science.gov (United States)

    2014-08-01

    invite leading experts from the full range of industry to academia to cover the topics of wide bandgap nitride and oxide semiconductors , the...Tsukuba University) " Positron Annihilation Studies in InGaN" 12:10 pm - 12:30 pm Discussion 9 12:30 pm Lunch 1:30 pm - 4:00 pm Free Time 4:00 pm...SECURITY CLASSIFICATION OF: The Gordon Research Conference on DEFECTS IN SEMICONDUCTORS was held at Bentley University in Waltham, Massachusetts

  14. Physics Division Argonne National Laboratory description of the programs and facilities.

    Energy Technology Data Exchange (ETDEWEB)

    Thayer, K.J. [ed.

    1999-05-24

    The ANL Physics Division traces its roots to nuclear physics research at the University of Chicago around the time of the second world war. Following the move from the University of Chicago out to the present Argonne site and the formation of Argonne National Laboratory: the Physics Division has had a tradition of research into fundamental aspects of nuclear and atomic physics. Initially, the emphasis was on areas such as neutron physics, mass spectrometry, and theoretical studies of the nuclear shell model. Maria Goeppert Maier was an employee in the Physics Division during the time she did her Nobel-Prize-winning work on the nuclear shell model. These interests diversified and at the present time the research addresses a wide range of current problems in nuclear and atomic physics. The major emphasis of the current experimental nuclear physics research is in heavy-ion physics, centered around the ATLAS facility (Argonne Tandem-Linac Accelerator System) with its new injector providing intense, energetic ion beams over the fill mass range up to uranium. ATLAS is a designated National User Facility and is based on superconducting radio-frequency technology developed in the Physics Division. A small program continues in accelerator development. In addition, the Division has a strong program in medium-energy nuclear physics carried out at a variety of major national and international facilities. The nuclear theory research in the Division spans a wide range of interests including nuclear dynamics with subnucleonic degrees of freedom, dynamics of many-nucleon systems, nuclear structure, and heavy-ion interactions. This research makes contact with experimental research programs in intermediate-energy and heavy-ion physics, both within the Division and on the national and international scale. The Physics Division traditionally has strong connections with the nation's universities. We have many visiting faculty members and we encourage students to participate in our

  15. Criteria and application methodology of physical protection of nuclear materials within the national and regional boundaries

    International Nuclear Information System (INIS)

    Rodriguez, C.E.; Cesario, R.H.; Giustina, D.H.; Canibano, J.

    1998-01-01

    Full text: The physical protection against robbery, diversion of nuclear materials and sabotage of nuclear installations by individuals or groups, has been for long time the reason of national and international concern. Even though, the obligation to create and implement an effective physical protection system for nuclear materials and installations in the territory of a given State, fall entirely on the State's Government, whether this obligation is fulfilled or not, and if it does, in what measure or up to what extent, it also concerns the rest of the States. Therefore, physical protection has become the reason for a regional co-operation. It is evident the need of co-operation in those cases where the physical protection efficiency within the territory of a given State depends also on the appropriate measures other States are taken, specially when dealing with materials been transported through national borders. The above mentioned constitute an important framework for the regional co-operation for the physical protection of nuclear materials. For that reason, the Nuclear Regulatory Authority established criteria and conditions aimed at mitigate diversions, robberies and sabotage to nuclear installations. As a working philosophy, it was established a simplify physical protection model of application in Argentina who, through the ARCAL No. 23 project, will be extrapolated to the whole Latin-American region, concluding that the application of the appropriated physical protection systems at regional level will lead to the strengthening of it at national level. (author) [es

  16. CHILDREN'S EDUCATION IN THE REGULAR NATIONAL BASIS: ASSUMPTIONS AND INTERFACES WITH PHYSICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    André da Silva Mello

    2016-09-01

    Full Text Available This paper aims at discussing the Children's Education organization within the Regular Curricular National Basis (BNCC, focusing on the permanencies and advances taking in relation to the precedent documents, and analyzing the presence of Physical Education in Children's Education from the assumptions that guide the Base, in interface with researches about pedagogical experiences with this field of knowledge. To do so, it carries out a documental-bibliographic analysis, using as sources the BNCC, the National Curricular Referential for Children's Education, the National Curricular Guidelines for Children's Education and academic-scientific productions belonging to the Physical Education area that approach Children's Education. In the analysis process, the work establishes categories which allow the interlocution among different sources used in this study. Data analyzed offers indications that the assumption present in the BNCC dialogue, not explicitly, with the movements of the curricular component and with the Physical Education academic-scientific production regarding Children's Education.

  17. [Physical activity in outpatients with type 2 diabetes in a National Hospital of Peru].

    Science.gov (United States)

    Manzaneda, Ana Josefina; Lazo-Porras, María; Málaga, Germán

    2015-01-01

    In order to determine the level of physical activity performed by outpatients with type 2 diabetes seen at a National Hospital in Lima, Peru, we surveyed 120 patients with the International Physical Activity Questionnaire (IPAQ). 66% were women, the mean age was 61.6 years, and 70% had poor glycemic control. 20% of the patients qualified as inactive, 68% as minimally active, and 12% had adequate physical activity. No relationship between physical activity, duration of disease, glycemic control, and body mass index was found. Age was negatively associated with physical activity. It is concluded that there are low levels of physical activity in patients with Type 2 diabetes and these are not focused on leisure activities that provide health benefits.

  18. Development of a testlet generator in re-engineering the Indonesian physics national-exams

    Science.gov (United States)

    Mindyarto, Budi Naini; Mardapi, Djemari; Bastari

    2017-08-01

    The Indonesian Physics national-exams are end-of-course summative assessments that could be utilized to support the assessment for learning in physics educations. This paper discusses the development and evaluation of a testlet generator based on a re-engineering of Indonesian physics national exams. The exam problems were dissected and decomposed into testlets revealing the deeper understanding of the underlying physical concepts by inserting a qualitative question and its scientific reasoning question. A template-based generator was built to facilitate teachers in generating testlet variants that would be more conform to students' scientific attitude development than their original simple multiple-choice formats. The testlet generator was built using open source software technologies and was evaluated focusing on the black-box testing by exploring the generator's execution, inputs and outputs. The results showed the correctly-performed functionalities of the developed testlet generator in validating inputs, generating testlet variants, and accommodating polytomous item characteristics.

  19. Physics Teachers' Behavioral, Control and Normative Beliefs about Teaching Physics According to the National High School Physics Curriculum in Turkey

    Science.gov (United States)

    Kapucu, Serkan; Yildirim, Ufuk

    2014-01-01

    In Turkey, a new Turkish High School Physics Curriculum (THSPC) was put into practice, starting initially with the Grade 9 in the 2008-2009 education-year. When compared with the previous ones, this curriculum emphasized the importance of students' active involvement in learning, use of real-life contexts and development of new skills. Even though…

  20. Physical exercise during pregnancy and fetal growth measures: a study within the Danish National Birth Cohort

    DEFF Research Database (Denmark)

    Juhl, Mette; Olsen, Jørn; Andersen, Per Kragh

    2010-01-01

    OBJECTIVE: The objective of the study was to examine the association between physical exercise during pregnancy and fetal growth measures. STUDY DESIGN: Data on 79,692 liveborn singletons from the Danish National Birth Cohort were collected between 1996 and 2002. Mean differences in birthweight, ...... effects on fetal growth measures related to exercise apart from a modest decreased risk of small- and large-for-gestational-age infants. These findings do not speak against advising pregnant women to be physically active during pregnancy....

  1. The impact of a national strategy to increase physical activity among older adults on national organizations.

    Science.gov (United States)

    Park, Chae-Hee; Chodzko-Zajko, Wojtek; Ory, Marcia G; Gleason-Senior, Jane; Bazzarre, Terry L; Mockenhaupt, Robin

    2010-10-01

    This study was designed to evaluate the impact of the National Blueprint (NB) on the policies, programs, and organizational culture of selected national organizations. The theoretical model selected to assess the impact of the NB on organizational behavior was Burke's system theory of organizational change. Three organizations, AARP, the American College of Sports Medicine (ACSM), and the Administration on Aging (AoA), were selected for the study. Two individuals in each of these organizations were selected for interview. Semistructured interviews and document reviews were used in the data-collection process. Findings showed that the publication and establishment of the NB resulted in changes in the operating procedures of AARP, ACSM, and AoA. The results were broadly consistent with Burke's system theory of organizational change. The publication of the NB was shown to affect the behavior of organizational leaders, organizational culture, policies, programs, and individual and organizational performance. The new information generated has increased our understanding of the impact of health campaigns on organizational behavior.

  2. Applications of the INFCIRC225/rev5 to the national physical protection regime

    International Nuclear Information System (INIS)

    Kim, Jae Gwang

    2011-01-01

    The IAEA's first effort for playing a key role in physical protection of nuclear material and facilities resulted in the publication of 'Recommendations for the physical protection of nuclear material' in 1972. These recommendations were revised by a group of experts in co-operation with the IAEA Secretariat and the revised version was published in 1975 in INFCIRC/225. The document was subsequently revised in 1977(rev.1), 1989(rev.2), in 1993(rev.3) and 1998(rev4). The Physical Protection regime in ROK has been established on the basis of INFCIRC225 rev4 since 2004 IAEA recently published The INFCIRC 225 rev5 through the 2 years expert consultations. The publication recommended 12 nuclear security fundamentals and requirements of physical protection of nuclear material and nuclear facility to the member states. This paper suggests the several applications to the national physical protection system from the 12 fundamentals and the requirements

  3. Solid spectroscopy: semiconductors

    International Nuclear Information System (INIS)

    Silva, C.E.T.G. da

    1983-01-01

    Photoemission as technique of study of the semiconductor electronic structure is shortly discussed. Homogeneous and heterogeneous semiconductors, where volume and surface electronic structure, core levels and O and H chemisorption in GaAs, Schottky barrier are treated, respectively. Amorphous semiconductors are also discussed. (L.C.) [pt

  4. Will Future Measurement Needs of the Semiconductor Industry Be Met?

    Science.gov (United States)

    Bennett, Herbert S

    2007-01-01

    We discuss the ability of the nation's measurement system to meet future metrology needs of the semiconductor industry. Lacking an acceptable metric for assessing the health of metrology for the semiconductor industry, we identify a limited set of unmet measurement needs. Assuming that this set of needs may serve as proxy for the galaxy of semiconductor measurement needs, we examine it from the perspective of what will be required to continue the semiconductor industry's powerful impact in the world's macro-economy and maintain its exceptional record of numerous technological innovations. This paper concludes with suggestions about ways to strengthen the measurement system for the semiconductor industry.

  5. Trends in prevalence of leisure time physical activity and inactivity: results from Australian National Health Surveys 1989 to 2011.

    Science.gov (United States)

    Chau, Josephine; Chey, Tien; Burks-Young, Sarah; Engelen, Lina; Bauman, Adrian

    2017-12-01

    To examine trends in leisure time physical activity and inactivity in Australians aged 15 years or older from 1989 to 2011. We used data from six Australian National Health Surveys conducted from 1989/90 to 2011/12 in which physical activity was assessed using comparable questions. Analyses examined trends in the prevalence of sufficient physical activity (≥150 minutes/week moderate-to-vigorous physical activity) and of inactivity (benefits from sufficient physical activity. Maintenance of consistent physical activity questions in future National Health Surveys will facilitate long term tracking of physical activity levels in the Australian population. © 2017 The Authors.

  6. Physics of societal issues calculations on national security, environment, and energy

    CERN Document Server

    Hafemeister, David

    2007-01-01

    Why this book on the Physics of Societal Issues? The subdivisions of physics - nuclear physics, particle physics, condensed-matter physics, biophysics - have their textbooks, while the subdivision of physics and society lacks an equation-oriented text on the physics of arms, energy and the environment. Physics of Societal Issues is intended for undergraduate and doctoral students who may work on applied topics, or who simply want to know why things are the way they are. Decisions guiding policies on nuclear arms, energy and the environment often seem mysterious and contradictory. What is the science behind the deployment of MIRVed ICBMs, the quest for space-based beam weapons, the fear of powerline EM fields, the wholesale acceptance of SUVs, the issues of climactic change, and the failure of the pre-embargo market to produce buildings and appliances that now save over 50 power plants? Physics of Societal Issues is three "mini-texts" in one: National Security (5 chapters): Weapons, offense, defense, verificat...

  7. United Nations Sustainable Development Goals: Promoting Health and Well-Being through Physical Education Partnerships

    Science.gov (United States)

    Lynch, Timothy

    2016-01-01

    This paper shares a health and wellbeing partnership, modelling implementation of physical education (PE) advocated by the United Nations (UN). The Sustainable Development Goals (SDGs) exemplifies global efforts towards equality, specifically Goal 3 and 4 address health and wellbeing. The purpose of this paper is to provide insights into cross…

  8. Proceedings of the 12. National Meeting on Particle Physics and Fields

    International Nuclear Information System (INIS)

    Santos, A.L.; Simoes, J.A.M.; Chinellato, J.A.; Pleitez, V.

    1993-01-01

    This publication contains the Proceedings presented during the 12. National Meeting on Particle Physics and Fields. Works on the areas of gravitation, quantum mechanics, string models; symmetry, current algebras, interaction models; particle decays, and theory of fields were proposed and discussed. (M.C.K.)

  9. Comparative Analyses of Physics Candidates Scores in West African and National Examinations Councils

    Science.gov (United States)

    Utibe, Uduak James; Agah, John Joseph

    2015-01-01

    The study is a comparative analysis of physics candidates' scores in West African and National Examinations Councils. It also investigates influence of gender. Results of 480 candidates were randomly selected form three randomly selected Senior Science Colleges using the WASSCE and NECOSSCE computer printout sent to the schools, transformed using…

  10. A National Perspective of Competencies for Teachers of Individuals with Physical and Health Disabilities.

    Science.gov (United States)

    Heller, Kathryn Wolff; Fredrick, Laura D.; Dykes, Mary Kay; Best, Sherwood; Cohen, Elisabeth Tucker

    1999-01-01

    A national study involving 59 teachers instructing students with physical and health disabilities, 26 universities, 36 local school system directors, and 29 state departments of education, found over 40% of the teachers did not feel well trained in half of the competencies. Concerns regarding the effects of generic teacher certification are…

  11. Proceedings of the 14. national meeting on particle physics and fields

    International Nuclear Information System (INIS)

    1994-01-01

    This publication contains the papers presented during the 14. national meeting on particle physics and fields. Works on the areas of gravitation, cosmology, quantum mechanics, string models; symmetry, current algebras, interaction models; particle decays and theory of fields were proposed and discussed

  12. "In the Nation's Good": Physical Education and School Sport in Singapore

    Science.gov (United States)

    Fry, Joan Marian; McNeill, Michael Charles

    2011-01-01

    Since independence in 1965, education and sport have been instrumental in Singapore's nation building, with a rapid rise in education and economic status. This article examines the roles of physical education and school sport in the local context and makes comparison with global themes ("instrumentality" and "marginality"). It…

  13. The First National Study of Neighborhood Parks: Implications for Physical Activity.

    Science.gov (United States)

    Cohen, Deborah A; Han, Bing; Nagel, Catherine J; Harnik, Peter; McKenzie, Thomas L; Evenson, Kelly R; Marsh, Terry; Williamson, Stephanie; Vaughan, Christine; Katta, Sweatha

    2016-10-01

    An extensive infrastructure of neighborhood parks supports leisure time physical activity in most U.S. cities; yet, most Americans do not meet national guidelines for physical activity. Neighborhood parks have never been assessed nationally to identify their role in physical activity. Using a stratified multistage sampling strategy, a representative sample of 174 neighborhood parks in 25 major cities (population >100,000) across the U.S. was selected. Park use, park-based physical activity, and park conditions were observed during a typical week using systematic direct observation during spring/summer of 2014. Park administrators were interviewed to assess policies and practices. Data were analyzed in 2014-2015 using repeated-measure negative binomial regressions to estimate weekly park use and park-based physical activity. Nationwide, the average neighborhood park of 8.8 acres averaged 20 users/hour or an estimated 1,533 person hours of weekly use. Walking loops and gymnasia each generated 221 hours/week of moderate to vigorous physical activity. Seniors represented 4% of park users, but 20% of the general population. Parks were used less in low-income than in high-income neighborhoods, largely explained by fewer supervised activities and marketing/outreach efforts. Programming and marketing were associated with 37% and 63% more hours of moderate to vigorous physical activity/week in parks, respectively. The findings establish national benchmarks for park use, which can guide future park investments and management practices to improve population health. Offering more programming, using marketing tools like banners and posters, and installing facilities like walking loops, may help currently underutilized parks increase population physical activity. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Argonne National Laboratory, High Energy Physics Division, semiannual report of research activities, July 1, 1989--December 31, 1989

    International Nuclear Information System (INIS)

    1989-01-01

    This report discusses research being conducted at the Argonne National Laboratory in the following areas: Experimental High Energy Physics; Theoretical High Energy Physics; Experimental Facilities Research; Accelerator Research and Development; and SSC Detector Research and Development

  15. The National Programme of Stellar Physics. Assessment 2011-2014. Prospective 2015-2018

    International Nuclear Information System (INIS)

    Bontemps, Sylvain; Bouchy, Francois; Charbonnel, Corinne; Chieze, Jean-Pierre; Dessart, Luc; Dintrans, Boris; Dougados, Catherine; Josselin, Eric; Kervella, Pierre; Martins, Fabrice; Michel, Eric; Moraux, Estelle; Recio-Blanco, Alejandra; Ristorcelli, Isabelle; Reyle, Celine; Alecian, Evelyne; Bouchy, Francois; Ciardi, Andrea; Dintrans, Boris; Herpin, Fabrice; Jouve, Laurene; Lebreton, Yveline; Motte, Frederique; Nardetto, Nicolas; Robin, Annie; Royer, Frederic; Samadi, Reza

    2015-04-01

    After an introduction which outlines the role of stellar physics as a keystone of research in astrophysics, this report proposes a presentation of the operation of the French national programme of stellar physics (PNPS): status and general operation, annual operation, statistics of budget and calls for bids, scientific animation, education, communication, community census, assessment of projects and thesis. It presents an overview of priority research theses between 2011 and 2014, according to their theme: stellar formation and protoplanetary disks, stellar structure and evolutions, origin and impact of magnetism, and atmospheres, winds and mass loss. Transverse theses are also presented the same way for the same period, with the following themes: basic physics, numeric simulations. The last part presents prospectives in terms of events (colloquium), bodies (new scientific council), themes to be studied, operation (interdisciplinarity and interfaces), means, general recommendations, and strengths and weaknesses of the national community

  16. Landmarks in particle physics at Brookhaven National Laboratory: Brookhaven Lecture Series, Number 238

    International Nuclear Information System (INIS)

    Adair, R.K.

    1987-01-01

    Robert Adair's lecture on Landmarks in Particle Physics at Brookhaven National Laboratory (BNL) is a commemoration of the 40th Anniversary of Brookhaven National Laboratory. Adair describes ten researches in elementary particle physics at Brookhaven that had a revolutionary impact on the understanding of elementary particles. Two of the discoveries were made in 1952 and 1956 at the Cosmotron, BNL's first proton accelerator. Four were made in 1962 and 1964 at the Alternating Gradient Synchrotron, the Cosmotron's replacement. Two other discoveries in 1954 and 1956 were theoretical, and strong focusing (1952) is the only technical discovery. One discovery (1958) happened in an old barrack. Four of the discoveries were awarded the Nobel prize in Physics. Adair believes that all of the discoveries are worthy of the Nobel prize. 14 figs

  17. ANALYSIS OF DIFFICULTY LEVEL OF PHYSICS NATIONAL EXAMINATION’S QUESTIONS

    Directory of Open Access Journals (Sweden)

    Yusrizal Yusrizal

    2016-04-01

    Full Text Available This study aimed to determine: (1 the difficulty level of items in physics National Exam of 2013 (2 physics materials that were difficult and very difficult. The subjects were all students of science major in third gradeat SMAN Banda Aceh in the academic year of 2013/2014. The samples were 10 randomly selected senior high schools. The data were obtained through analyzing the answers of physics National Examin 2013. The results showed that (1 the high school students in Banda Aceh experienced difficult and very difficult level questions to be answer in the 2013 exam, (2 thedifficult materials were: free fall, the potential energy and series of obstacles. The very difficult materials were: the rotational motion, motion and force on the pulley, effort, fluid, sound intensity, transformer, atomic theory, quantum theory, relativity, fusion and radio isotopes.

  18. Improvements in or relating to semiconductor devices

    International Nuclear Information System (INIS)

    Cooper, K.; Groves, I.S.; Leigh, P.A.; McIntyre, N.; O'Hara, S.; Speight, J.D.

    1980-01-01

    A method of producing semiconductor devices is described consisting of a series of physical and chemical techniques which results in the production of semiconductor devices such as IMPATT diodes of DC-RF efficiency and high reliability (lifetime). The diodes can be mass produced without significant variation of the technology. One of the techniques used is the high energy proton bombardment of the semiconductor material in depth to passivate specific zones. The energy of the protons is increased in stages at intervals of less than 0.11 MeV up to a predetermined maximum energy. (UK)

  19. Skylab experiments. Volume 3: Materials science. [Skylab experiments on metallurgy, crystal growth, semiconductors, and combustion physics in weightless environment for high school level education

    Science.gov (United States)

    1973-01-01

    The materials science and technology investigation conducted on the Skylab vehicle are discussed. The thirteen experiments that support these investigations have been planned to evaluate the effect of a weightless environment on melting and resolidification of a variety of metals and semiconductor crystals, and on combustion of solid flammable materials. A glossary of terms which define the space activities and a bibliography of related data are presented.

  20. The association of menopause status with physical function: the Study of Women's Health Across the Nation.

    Science.gov (United States)

    Tseng, Lisa A; El Khoudary, Samar R; Young, Elizabeth A; Farhat, Ghada N; Sowers, MaryFran; Sutton-Tyrrell, Kim; Newman, Anne B

    2012-11-01

    The aim of this study was to determine whether postmenopause status is associated with self-reported limitations in physical function. The Study of Women's Health Across the Nation is a multisite, multiethnic, longitudinal study of midlife women. Women aged 45 to 57 years (N = 2,566) completed the physical function scale of the Medical Outcomes Study Short-Form 36 on visit 4 (2000-2001). Scores created a three-category variable of physical function limitations: none (86-100), moderate (51-85), and substantial (0-50). In the Study of Women's Health Across the Nation, menopause status is a five-category list variable based on menstrual bleeding patterns and gynecological surgery. Premenopausal and perimenopausal women using hormones (n = 284) or missing physical function scores (n = 46) were excluded. Multinomial logistic regression was used to relate physical function and menopause status after adjustment for age, ethnicity, site, education, body mass index (BMI), and self-reported diabetes, hypertension, arthritis, depressive symptoms, smoking, and hormone use among postmenopausal women. Of 2,236 women, 8% were premenopausal, 51% were early perimenopausal, 12% were late perimenopausal, 24% were naturally postmenopausal, and 5% were surgically postmenopausal. In the full model, substantial limitations in physical function were higher in postmenopausal women, whether naturally postmenopausal (odds ratio, 3.82; 95% CI, 1.46-10.0) or surgically postmenopausal (odds ratio, 3.54; 95% CI, 1.15-10.84), than in premenopausal women. These associations were attenuated by higher BMI and depressive symptoms but remained significant. Moderate limitations in physical function were not significantly related to menopause status. Women experiencing surgical or naturally occurring postmenopause report greater limitations in physical function compared with premenopausal women, independent of age and only partly explained by higher BMI and depressive symptoms. This suggests that

  1. Nitride semiconductor devices fundamentals and applications

    CERN Document Server

    Morkoç, Hadis

    2013-01-01

    This book gives a clear presentation of the necessary basics of semiconductor and device physics and engineering. It introduces readers to fundamental issues that will enable them to follow the latest technological research. It also covers important applications, including LED and lighting, semiconductor lasers, high power switching devices, and detectors. This balanced and up-to-date treatment makes the text an essential educational tool for both advanced students and professionals in the electronics industry.

  2. The physical examination content of the Japanese National Health and Nutrition Survey: temporal changes.

    Science.gov (United States)

    Tanaka, Hisako; Imai, Shino; Nakade, Makiko; Imai, Eri; Takimoto, Hidemi

    2016-12-01

    Survey items of the Japan National Nutrition Survey (J-NNS) have changed over time. Several papers on dietary surveys have been published; however, to date, there are no in-depth papers regarding physical examinations. Therefore, we investigated changes in the survey items in the physical examinations performed in the J-NNS and the National Health and Nutrition Survey (NHNS), with the aim of incorporating useful data for future policy decisions. We summarized the description of physical examinations and marshalled the changes of survey items from the J-NNS and NHNS from 1946 to 2012. The physical examination is roughly classified into the following six components: some are relevant to anthropometric measurements, clinical measurements, physical symptoms, blood tests, lifestyle and medication by interview, and others. Items related to nutritional deficiency, such as anaemia and tendon reflex disappearance, and body weight measurements were collected during the early period, according to the instructions of the General Headquarters. From 1989, blood tests and measurement of physical activity were added, and serum total protein, total cholesterol, triglycerides, HDL-cholesterol, blood glucose, red blood corpuscles and haemoglobin measurements have been performed continuously for more than 20 years. This is the first report on the items of physical examination in the J-NNS and NHNS. Our research results provide basic information for the utilization of the J-NNS and NHNS, to researchers, clinicians or policy makers. Monitoring the current state correctly is essential for national health promotion, and also for improvement of the investigation methods to apply country-by-country comparisons.

  3. Physical activity promotion in business and industry: evidence, context, and recommendations for a national plan.

    Science.gov (United States)

    Pronk, Nicolaas P

    2009-11-01

    The contemporary workplace setting is in need of interventions that effectively promote higher levels of occupational and habitual physical activity. It is the purpose of this paper to outline an evidence-based approach to promote physical activity in the business and industry sector in support of a National Physical Activity Plan. Comprehensive literature searches identified systematic reviews, comprehensive reviews, and consensus documents on the impact of physical activity interventions in the business and industry sector. A framework for action and priority recommendations for practice and research were generated. Comprehensive, multicomponent work-site programs that include physical activity components generate significant improvements in health, reduce absenteeism and sick leave, and can generate a positive financial return. Specific evidence-based physical activity interventions are presented. Recommendations for practice include implementing comprehensive, multicomponent programs that make physical activity interventions possible, simple, rewarding and relevant in the context of a social-ecological model. The business and industry sector has significant opportunities to improve physical activity among employees, their dependents, and the community at-large and to reap important benefits related to worker health and business performance.

  4. Associations between positive and negative affect and 12-month physical disorders in a national sample.

    Science.gov (United States)

    Weiser, Eric B

    2012-06-01

    Associations between positive and negative affect and a range of 12-month physical disorders were investigated in the Midlife Development in the United States Survey, a nationally representative sample of 3,032 adults ages 25-74. These associations were examined, controlling for relevant sociodemographic and psychiatric covariates. High positive affect was associated with decreased risk of physical disorders, whereas high negative affect was associated with increased risk. However, associations between positive affect and physical disorders were partially attenuated following adjustment for concurrent negative affect. Additionally, high affect balance was associated with decreased risk of physical disorders before and after adjustments. These findings underscore the relevance of affective disposition in health status, suggesting that both positive and negative affect may serve as viable health risk parameters.

  5. PREFACE: 16th Nordic Semiconductor Meeting

    Science.gov (United States)

    Pétur Gíslason, Hafliði; Guðmundsson, Viðar

    1994-01-01

    Some 30 years ago an informal meeting of the few Nordic specialists in semiconductor physics marked the beginning of what has become a biannual meeting of some hundred physicists and physics students from all the Nordic countries. The 16th Nordic Semiconductor Meeting took place at Laugarvatn, Iceland, June 12-15,1994. As a regional meeting the Nordic Semiconductor meeting has three characteristic features all of which distinguish it from more traditional international meetings in the field. First, it has the purpose of promoting Nordic cooperation in the international field of semiconductor physics. Research in the fields of advanced science and technology in the Nordic countries is likely to benefit from joining national forces before participating in the increasing European integration. Second, there is an unusually large fraction of graduate students amongst the participants of the Nordic Semiconductor Meeting. In fact, attending this conference is traditionally a part of the graduate program in seniconductor physics and technology. The Nordic Semiconductor Meeting is often the first conference of international character that graduate students attend in order to present a paper of poster. Third, there is an interdisciplinary quality of the meeting which is normally not the case for meetings of this size. In particular, the number of professional scientists from industry is comparable to the number of their academic colleagues. This is important for both groups, but perhaps the graduate students benefit most from presenting their results to both groups. The 16th Nordic Semiconductor Meeting, the first one in this series held in Iceland, attracted 129 active participants. The scientific programme was divided in twelve oral sessions. A novelty of this meeting was the emphasis on more fundamental physics in one of the two parallel sessions but more applied topics in the other, although the distinction was sometimes a matter of predilection. A poster session

  6. The physics basis for ignition using indirect-drive targets on the National Ignition Facility

    International Nuclear Information System (INIS)

    Lindl, John D.; Amendt, Peter; Berger, Richard L.; Glendinning, S. Gail; Glenzer, Siegfried H.; Haan, Steven W.; Kauffman, Robert L.; Landen, Otto L.; Suter, Laurence J.

    2004-01-01

    The 1990 National Academy of Science final report of its review of the Inertial Confinement Fusion Program recommended completion of a series of target physics objectives on the 10-beam Nova laser at the Lawrence Livermore National Laboratory as the highest-priority prerequisite for proceeding with construction of an ignition-scale laser facility, now called the National Ignition Facility (NIF). These objectives were chosen to demonstrate that there was sufficient understanding of the physics of ignition targets that the laser requirements for laboratory ignition could be accurately specified. This research on Nova, as well as additional research on the Omega laser at the University of Rochester, is the subject of this review. The objectives of the U.S. indirect-drive target physics program have been to experimentally demonstrate and predictively model hohlraum characteristics, as well as capsule performance in targets that have been scaled in key physics variables from NIF targets. To address the hohlraum and hydrodynamic constraints on indirect-drive ignition, the target physics program was divided into the Hohlraum and Laser-Plasma Physics (HLP) program and the Hydrodynamically Equivalent Physics (HEP) program. The HLP program addresses laser-plasma coupling, x-ray generation and transport, and the development of energy-efficient hohlraums that provide the appropriate spectral, temporal, and spatial x-ray drive. The HEP experiments address the issues of hydrodynamic instability and mix, as well as the effects of flux asymmetry on capsules that are scaled as closely as possible to ignition capsules (hydrodynamic equivalence). The HEP program also addresses other capsule physics issues associated with ignition, such as energy gain and energy loss to the fuel during implosion in the absence of alpha-particle deposition. The results from the Nova and Omega experiments approach the NIF requirements for most of the important ignition capsule parameters, including

  7. Simbios: an NIH national center for physics-based simulation of biological structures.

    Science.gov (United States)

    Delp, Scott L; Ku, Joy P; Pande, Vijay S; Sherman, Michael A; Altman, Russ B

    2012-01-01

    Physics-based simulation provides a powerful framework for understanding biological form and function. Simulations can be used by biologists to study macromolecular assemblies and by clinicians to design treatments for diseases. Simulations help biomedical researchers understand the physical constraints on biological systems as they engineer novel drugs, synthetic tissues, medical devices, and surgical interventions. Although individual biomedical investigators make outstanding contributions to physics-based simulation, the field has been fragmented. Applications are typically limited to a single physical scale, and individual investigators usually must create their own software. These conditions created a major barrier to advancing simulation capabilities. In 2004, we established a National Center for Physics-Based Simulation of Biological Structures (Simbios) to help integrate the field and accelerate biomedical research. In 6 years, Simbios has become a vibrant national center, with collaborators in 16 states and eight countries. Simbios focuses on problems at both the molecular scale and the organismal level, with a long-term goal of uniting these in accurate multiscale simulations.

  8. Review of the National Research Council report: Physics through the 1990's

    International Nuclear Information System (INIS)

    1987-02-01

    The report of the National Research Council (NRC), Physics through the 1990s, highlights past developments and research opportunities in the various subfields of physics and addresses general issues concerning the present state of the discipline in the United States. At the request of the Secretary of Energy, the Energy Research Advisory Board (ERAB) reviewed this report and identified the areas that relate to the programs and objectives of the Department of Energy (DOE). The present report provides the conclusions of this review and the recommendations for the Department's actions

  9. National health education programs to promote healthy eating and physical activity.

    Science.gov (United States)

    Donato, Karen A

    2006-02-01

    The national education programs and campaigns described here are examples of the many unique kinds of federal efforts under way to promote the pillars of healthy eating and increased physical activity included in the "Healthier US Initiative." They are similar in that: 1) they are based on the best available science that a health problem exists, and 2) that healthy eating and physical active behaviors will improve health status. They are unique in their implementation, for example, in private/public partnerships, coordinating committees of professional associations, and congressionally mandated interventions. Most importantly, they provide the impetus to get a particular health issue on the public agenda.

  10. UK semiconductor tracker parts head for CERN

    CERN Multimedia

    Holland, Colin

    2005-01-01

    The last of the 4 barrels that make up the central part of the Semiconductor Tracker (SCT), the heart of the biggest physics collaboration in the world have left Oxford for its new home at the European Particle Physics Laboratory, CERN, near Geneva

  11. Kansas Advanced Semiconductor Project: Final Report

    International Nuclear Information System (INIS)

    Baringer, P.; Bean, A.; Bolton, T.; Horton-Smith, G.; Maravin, Y.; Ratra, B.; Stanton, N.; von Toerne, E.; Wilson, G.

    2007-01-01

    KASP (Kansas Advanced Semiconductor Project) completed the new Layer 0 upgrade for D0, assumed key electronics projects for the US CMS project, finished important new physics measurements with the D0 experiment at Fermilab, made substantial contributions to detector studies for the proposed e+e- international linear collider (ILC), and advanced key initiatives in non-accelerator-based neutrino physics.

  12. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

    Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

    2005-01-01

    In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

  13. Semiconductor apparatus and method of fabrication for a semiconductor apparatus

    NARCIS (Netherlands)

    2010-01-01

    The invention relates to a semiconductor apparatus (1) and a method of fabrication for a semiconductor apparatus (1), wherein the semiconductor apparatus (1) comprises a semiconductor layer (2) and a passivation layer (3), arranged on a surface of the semiconductor layer (2), for passivating the

  14. Solid-state NMR of inorganic semiconductors.

    Science.gov (United States)

    Yesinowski, James P

    2012-01-01

    Studies of inorganic semiconductors by solid-state NMR vary widely in terms of the nature of the samples investigated, the techniques employed to observe the NMR signal, and the types of information obtained. Compared with the NMR of diamagnetic non-semiconducting substances, important differences often result from the presence of electron or hole carriers that are the hallmark of semiconductors, and whose theoretical interpretation can be involved. This review aims to provide a broad perspective on the topic for the non-expert by providing: (1) a basic introduction to semiconductor physical concepts relevant to NMR, including common crystal structures and the various methods of making samples; (2) discussions of the NMR spin Hamiltonian, details of some of the NMR techniques and strategies used to make measurements and theoretically predict NMR parameters, and examples of how each of the terms in the Hamiltonian has provided useful information in bulk semiconductors; (3) a discussion of the additional considerations needed to interpret the NMR of nanoscale semiconductors, with selected examples. The area of semiconductor NMR is being revitalized by this interest in nanoscale semiconductors, the great improvements in NMR detection sensitivity and resolution that have occurred, and the current interest in optical pumping and spintronics-related studies. Promising directions for future research will be noted throughout.

  15. Total physical activity volume, physical activity intensity, and metabolic syndrome: 1999-2004 National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Churilla, James R; Fitzhugh, Eugene C

    2012-02-01

    This study examined the association of total physical activity volume (TPAV) and physical activity (PA) from three domains [leisure-time physical activity (LTPA), domestic, transportation] with metabolic syndrome. We also investigated the relationship between LTPA intensity and metabolic syndrome risk. Sample included adults who participated in the 1999-2004 National Health and Nutrition Examination Survey. Physical activity measures were created for TPAV, LTPA, domestic PA, and transportational PA. For each, a six-level measure based upon no PA (level 1) and quintiles (levels 2-6) of metabolic equivalents (MET)·min·wk(-1) was created. A three-level variable associated with the current Department of Health and Human Services (DHHS) PA recommendation was also created. SAS and SUDAAN were used for the statistical analysis. Adults reporting the greatest volume of TPAV and LTPA were found to be 36% [odds ratio (OR) 0.64; 95% confidence interval (CI) 0.49-0.83] and 42% (OR 0.58; 95% CI 0.43-0.77), respectively, less likely to have metabolic syndrome. Domestic and transportational PA provided no specific level of protection from metabolic syndrome. Those reporting a TPAV that met the DHHS PA recommendation were found to be 33% (OR 0.67; 95%; CI 0.55-0.83) less likely to have metabolic syndrome compared to their sedentary counterparts. Adults reporting engaging in only vigorous-intensity LTPA were found to be 37% (OR 0.63; 95 CI 0.42-0.96) to 56% (OR 0.44; 95% CI 0.29-0.67) less likely to have metabolic syndrome. Volume, intensity, and domain of PA may all play important roles in reducing the prevalence and risk of metabolic syndrome.

  16. Elder mistreatment predicts later physical and psychological health: Results from a national longitudinal study.

    Science.gov (United States)

    Wong, Jaclyn S; Waite, Linda J

    2017-01-01

    Stress process theory predicts that elder mistreatment leads to declines in health, and that social support buffers its ill effects. We test this theory using nationally representative, longitudinal data from 2,261 older adults in the National Social Life Health and Aging Project. We regress psychological and physical health in 2010/2011 on verbal and financial mistreatment experience in 2005/2006 and find that the mistreated have more anxiety symptoms, greater feelings of loneliness, and worse physical and functional health 5 years later than those who did not report mistreatment. In particular, we show a novel association between financial mistreatment and functional health. Contrary to the stress buffering hypothesis, we find little evidence that social support moderates the relationship between mistreatment and health. Our findings point to the lasting impact of mistreatment on health but show little evidence of a buffering role of social support in this process.

  17. The body of the nation: government positions on physical education during the Brazilian monarchy.

    Science.gov (United States)

    de Melo, Victor Andrade; Peres, Fabio de Faria

    2014-01-01

    In association with its nation building projects, the imperial government in Brazil under monarchic rule took some concrete actions based on proposals for physical education. The aim of this article is to investigate the meanings and significations attributed to this subject in the legislation and the annual reports issued by the Ministry of Business of the Empire (1831-1889), giving special attention to Rio de Janeiro. The approach to the subject in the sources researched demonstrates that the views of physical education took shape through a web of ideas that associated moral, health and civilization conceptions, in a bid to deal with the concrete circumstances of a newly independent peripheral nation with a bureaucratic structure in the process of formation.

  18. TOPICAL REVIEW: Advances in traceable nanometrology at the National Physical Laboratory†Advances in traceable nanometrology at the National Physical Laboratory

    Science.gov (United States)

    Leach, Richard; Haycocks, Jane; Jackson, Keith; Lewis, Andrew; Oldfield, Simon; Yacoot, Andrew

    2001-03-01

    The only difference between nanotechnology and many other fields of science or engineering is that of size. Control in manufacturing at the nanometre scale still requires accurate and traceable measurements whether one is attempting to machine optical quality glass or write one's company name in single atoms. A number of instruments have been developed at the National Physical Laboratory that address the measurement requirements of the nanotechnology community and provide traceability to the definition of the metre. The instruments discussed in this paper are an atomic force microscope and a surface texture measuring instrument with traceable metrology in all their operational axes, a combined optical and x-ray interferometer system that can be used to calibrate displacement transducers to subnanometre accuracy and a co-ordinate measuring machine with a working volume of (50 mm)3 and 50 nm volumetric accuracy.

  19. Association between physical activity and kidney function: National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Hawkins, Marquis S; Sevick, Mary Ann; Richardson, Caroline R; Fried, Linda F; Arena, Vincent C; Kriska, Andrea M

    2011-08-01

    Chronic kidney disease is a condition characterized by the deterioration of the kidney's ability to remove waste products from the body. Although treatments to slow the progression of the disease are available, chronic kidney disease may eventually lead to a complete loss of kidney function. Previous studies have shown that physical activities of moderate intensity may have renal benefits. Few studies have examined the effects of total movement on kidney function. The purpose of this study was to determine the association between time spent at all levels of physical activity intensity and sedentary behavior and kidney function. Data were obtained from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey, a cross-sectional study of a complex, multistage probability sample of the US population. Physical activity was assessed using an accelerometer and questionnaire. Glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease study formula. To assess linear associations between levels of physical activity and sedentary behavior with log-transformed estimated GFR (eGFR), linear regression was used. In general, physical activity (light and total) was related to log eGFR in females and males. For females, the association between light and total physical activity with log eGFR was consistent regardless of diabetes status. For males, the association between light and total physical activity and log eGFR was only significant in males without diabetes. When examining the association between physical activity, measured objectively with an accelerometer, and kidney function, total and light physical activities were found to be positively associated with kidney function.

  20. Establishment of Traceability of Reference Grade Hydrometers at National Physical Laboratory, India (npli)

    Science.gov (United States)

    Kumar, Anil; Kumar, Harish; Mandal, Goutam; Das, M. B.; Sharma, D. C.

    The present paper discusses the establishment of traceability of reference grade hydrometers at National Physical Laboratory, India (NPLI). The reference grade hydrometers are calibrated and traceable to the primary solid density standard. The calibration has been done according to standard procedure based on Cuckow's Method and the reference grade hydrometers calibrated covers a wide range. The uncertainty of the reference grade hydrometers has been computed and corrections are also calculated for the scale readings, at which observations are taken.

  1. National Study of Excellence and Innovation in Physical Therapist Education: Part 2-A Call to Reform.

    Science.gov (United States)

    Jensen, Gail M; Hack, Laurita M; Nordstrom, Terrence; Gwyer, Janet; Mostrom, Elizabeth

    2017-09-01

    This perspective shares recommendations that draw from (1) the National Study of Excellence and Innovation in Physical Therapist Education research findings and a conceptual model of excellence in physical therapist education, (2) the Carnegie Foundation's Preparation for the Professions Program (PPP), and (3) research in the learning sciences. The 30 recommendations are linked to the dimensions described in the conceptual model for excellence in physical therapist education: Culture of Excellence, Praxis of Learning, and Organizational Structures and Resources. This perspective proposes a transformative call for reform framed across 3 core categories: (1) creating a culture of excellence, leadership, and partnership, (2) advancing the learning sciences and understanding and enacting the social contract, and (3) implementing organizational imperatives. Similar to the Carnegie studies, this perspective identifies action items (9) that should be initiated immediately in a strategic and systematic way by the major organizational stakeholders in physical therapist education. These recommendations and action items provide a transformative agenda for physical therapist education, and thus the profession, in meeting the changing needs of society through higher levels of excellence. © 2017 American Physical Therapy Association.

  2. Progress in Group III nitride semiconductor electronic devices

    International Nuclear Information System (INIS)

    Hao Yue; Zhang Jinfeng; Shen Bo; Liu Xinyu

    2012-01-01

    Recently there has been a rapid domestic development in group III nitride semiconductor electronic materials and devices. This paper reviews the important progress in GaN-based wide bandgap microelectronic materials and devices in the Key Program of the National Natural Science Foundation of China, which focuses on the research of the fundamental physical mechanisms of group III nitride semiconductor electronic materials and devices with the aim to enhance the crystal quality and electric performance of GaN-based electronic materials, develop new GaN heterostructures, and eventually achieve high performance GaN microwave power devices. Some remarkable progresses achieved in the program will be introduced, including those in GaN high electron mobility transistors (HEMTs) and metal—oxide—semiconductor high electron mobility transistors (MOSHEMTs) with novel high-k gate insulators, and material growth, defect analysis and material properties of InAlN/GaN heterostructures and HEMT fabrication, and quantum transport and spintronic properties of GaN-based heterostructures, and high-electric-field electron transport properties of GaN material and GaN Gunn devices used in terahertz sources. (invited papers)

  3. Strategic Priorities for Increasing Physical Activity Among Adults Age 50 and Older: The National Blueprint Consensus Conference Summary Report

    OpenAIRE

    Sheppard, Lisa; Senior, Jane; Park, Chae Hee; Mockenhaupt, Robin; Bazzarre, Terry; Chodzko-Zajko, Wojtek

    2003-01-01

    On May 1, 2001, a coalition of national organizations released a major planning document designed to develop a national strategy for the promotion of physically active lifestyles among the mid-life and older adult population. The National Blueprint: Increasing Physical Activity Among Adults Age 50 and Older was developed with input from 46 organizations with expertise in health, medicine, social and behavioral sciences, epidemiology, gerontology/geriatrics, clinical science, public policy, ma...

  4. Solid state physics and physicists of the post war Latvia

    International Nuclear Information System (INIS)

    Zakis, J.

    2003-01-01

    In Latvia during the so-called post war period (1944-1991) fields that promoted the research activities were nuclear research and semiconductor electronics. Being considered as classified the researches in these fields were separated from the universities and transferred to the institutes of recently founded Latvian Academy of Sciences. The institutes related to the so-called sector management ministries performed the most of research in semiconductor physics. Research activities at the University of Latvia were mainly in the basic solid state physics (ionic crystals, Ferro ceramics). Despite of being controlled research activities in solid-state physics in Latvia were on relatively high level recognized both nationally and internationally

  5. Promotion of physical activity in the European region: content analysis of 27 national policy documents

    DEFF Research Database (Denmark)

    Daugbjerg, Signe B; Kahlmeier, Sonja; Racioppi, Francesca

    2009-01-01

    . Population groups most in need such as people with low levels of physical activity were rarely specifically targeted. Most policies emphasized the importance of an evaluation. However, only about half of them indicated a related intention or requirement. CONCLUSION: In recent years there has been......BACKGROUND: Over the past years there has been increasing interest in physical activity promotion and the development of appropriate policy. So far, there has been no comprehensive overview of the activities taking place in Europe in this area of public health policy. METHODS: Using different...... search methods, 49 national policy documents on physical activity promotion were identified. An analysis grid covering key features was developed for the analysis of the 27 documents published in English. RESULTS: Analysis showed that many general recommendations for policy developments are being...

  6. Slow and fast light in semiconductor waveguides

    DEFF Research Database (Denmark)

    Mørk, Jesper; Hansen, Per Lunnemann; Xue, Weiqi

    2010-01-01

    Investigations of slow and fast light effects in semiconductor waveguides entail interesting physics and point to a number of promising applications. In this review we give an overview of recent progress in the field, in particular focusing on the physical mechanisms of electromagnetically induced...... transparency and coherent population oscillations. While electromagnetically induced transparency has been the most important effect in realizing slowdown effects in atomic gasses, progress has been comparatively slow in semiconductors due to inherent problems of fast dephasing times and inhomogeneous...... broadening in quantum dots. The physics of electromagnetically induced transparency in semiconductors is discussed, emphasizing these limitations and recent suggestions for overcoming them. On the other hand, the mechanism of coherent population oscillations relies on wave mixing effects and is well suited...

  7. Integrating 3D geological information with a national physically-based hydrological modelling system

    Science.gov (United States)

    Lewis, Elizabeth; Parkin, Geoff; Kessler, Holger; Whiteman, Mark

    2016-04-01

    Robust numerical models are an essential tool for informing flood and water management and policy around the world. Physically-based hydrological models have traditionally not been used for such applications due to prohibitively large data, time and computational resource requirements. Given recent advances in computing power and data availability, a robust, physically-based hydrological modelling system for Great Britain using the SHETRAN model and national datasets has been created. Such a model has several advantages over less complex systems. Firstly, compared with conceptual models, a national physically-based model is more readily applicable to ungauged catchments, in which hydrological predictions are also required. Secondly, the results of a physically-based system may be more robust under changing conditions such as climate and land cover, as physical processes and relationships are explicitly accounted for. Finally, a fully integrated surface and subsurface model such as SHETRAN offers a wider range of applications compared with simpler schemes, such as assessments of groundwater resources, sediment and nutrient transport and flooding from multiple sources. As such, SHETRAN provides a robust means of simulating numerous terrestrial system processes which will add physical realism when coupled to the JULES land surface model. 306 catchments spanning Great Britain have been modelled using this system. The standard configuration of this system performs satisfactorily (NSE > 0.5) for 72% of catchments and well (NSE > 0.7) for 48%. Many of the remaining 28% of catchments that performed relatively poorly (NSE land cover change studies and integrated assessments of groundwater and surface water resources.

  8. Turning the tide: national policy approaches to increasing physical activity in seven European countries.

    Science.gov (United States)

    Bull, Fiona; Milton, Karen; Kahlmeier, Sonja; Arlotti, Alberto; Juričan, Andrea Backović; Belander, Olov; Martin, Brian; Martin-Diener, Eva; Marques, Ana; Mota, Jorge; Vasankari, Tommi; Vlasveld, Anita

    2015-06-01

    Physical inactivity is one of the four leading behavioural risk factors for non-communicable disease (NCD). Like tobacco control, increasing levels of health-enhancing physical activity (HEPA) will require a national policy framework providing direction and a clear set of actions. Despite frequent calls, there has been insufficient progress on policy development in the majority of countries around the world. This study sought and summarised national HEPA policy in seven European countries (Finland, Italy, the Netherlands, Norway, Portugal, Slovenia and Switzerland). Data collection used a policy audit tool (PAT), a 27-item instrument structured into four sections. All countries reported some legislation or policy across the sectors of education, sport and health. Only some countries reported supportive policy in the transport and environment sectors. Five countries reported a stand-alone HEPA policy and six countries reported national recommendations. HEPA prevalence targets varied in magnitude and specificity and the presence of other relevant goals from different sectors highlighted the opportunity for joint action. Evaluation and the use of scientific evidence were endorsed but described as weak in practice. Only two countries reported a national multisector coordinating committee and most countries reported challenges with partnerships on different levels of policy implementation. Bringing together the key components for success within a national HEPA policy framework is not simple. This in-depth policy audit and country comparison highlighted similarities and differences and revealed new opportunities for consideration by other countries. These examples can inform countries within and beyond Europe and guide the development of national HEPA policy within the NCD prevention agenda. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Semiconductor Electrical Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Electrical Measurements Laboratory is a research laboratory which complements the Optical Measurements Laboratory. The laboratory provides for Hall...

  10. Modelling colliding-pulse mode-locked semiconductor lasers

    DEFF Research Database (Denmark)

    Bischoff, Svend

    or to determine the optimum operation conditions. The purpose of this thesis is to elucidate some of the physics of interest in the field of semiconductor laser modelling, semiconductor optics and fiber optics. To be more specific we will investigate: The Colliding-Pulse Mode-Locked (CPM) Quantum Well (QW) laser...... diode; the excitonic semiconductor response for varying material thickness in the case of linear optics; and modulational instability of electromagnetic waves in media with spatially varying non-linearity....

  11. Physical and electrical characteristics of AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors with rare earth Er2O3 as a gate dielectric

    International Nuclear Information System (INIS)

    Lin, Ray-Ming; Chu, Fu-Chuan; Das, Atanu; Liao, Sheng-Yu; Chou, Shu-Tsun; Chang, Liann-Be

    2013-01-01

    In this study, the rare earth erbium oxide (Er 2 O 3 ) was deposited using an electron beam onto an AlGaN/GaN heterostructure to fabricate metal-oxide-semiconductor high-electron-mobility transistors (MOS–HEMTs) that exhibited device performance superior to that of a conventional HEMT. Under similar bias conditions, the gate leakage currents of these MOS–HEMT devices were four orders of magnitude lower than those of conventional Schottky gate HEMTs. The measured sub-threshold swing (SS) and the effective trap state density (N t ) of the MOS–HEMT were 125 mV/decade and 4.3 × 10 12 cm −2 , respectively. The dielectric constant of the Er 2 O 3 layer in this study was 14, as determined through capacitance–voltage measurements. In addition, the gate–source reverse breakdown voltage increased from –166 V for the conventional HEMT to –196 V for the Er 2 O 3 MOS–HEMT. - Highlights: ► GaN/AlGaN/Er 2 O 3 metal-oxide semiconductor high electron mobility transistor ► Physical and electrical characteristics are presented. ► Electron beam evaporated Er 2 O 3 with excellent surface roughness ► Device exhibits reduced gate leakage current and improved I ON /I OFF ratio

  12. Physical protection as the most important part of the national system of combating illicit trafficking

    International Nuclear Information System (INIS)

    Ivanov, P.; Kokhan, V.D.

    2001-01-01

    It is obvious today that illicit trafficking, including its most dangerous manifestations proliferation of nuclear weapons, smuggling of nuclear materials and equipment, presents a serious threat to the international community. To defeat this evil is possible only by joint efforts, by undertaken protective measures on national and international levels. Joint efforts should be directed at fulfilling three main tasks as follows: 1. Safe and reliable handling of nuclear material, effective measures of its physical protection, accountancy and control in order to prevent proliferation; 2. Joint activities of intelligence customs and law-enforcement authorities directed at prevention of international trafficking and marketing of stolen goods; 3. Joint activities directed at identification and prevention of illegal supply and demand of fissionable materials counteracting thereby various criminal structures. We believe that in order to solve these problems an international regime should be established. Such an international regime will make the states implement the existing international agreements that will strengthen their postings regarding non-proliferation of nuclear weapons, ensure combating of illicit trafficking as well as facilitating cooperation between national and international databases on non-proliferation of nuclear weapons, bilateral agreements between state authorities and international organizations regarding joint investigation procedures of the cases involving illicit trafficking. We believe that these goals of an international regime against illicit trafficking can be achieved by only one organization - the IAEA, an authority respected by the international community and presently responsible for nuclear safeguards. Recommendations and guidelines on physical protection, including the Convection on Physical Protection, have been developed under its auspices. The IAEA enjoys great respect and has extensive contacts including those with Interpol; it

  13. Replacement of the Idaho National Engineering Laboratory Health Physics Instrumentation Laboratory

    International Nuclear Information System (INIS)

    1995-05-01

    The DOE-Idaho Operations Office (DOE-ID) has prepared an environmental assessment (EA) on the replacement of the Idaho National Engineering Laboratory Health Physics Instrumentation Laboratory at the Idaho National Engineering Laboratory (INEL). The purpose of this project is to replace the existing Health Physics Instrumentation Laboratory (HPIL) with a new facility to provide a safe environment for maintaining and calibrating radiation detection instruments used at the Idaho National Engineering Laboratory. The existing HPIL facility provides portable health physics monitoring instrumentation and direct reading dosimetry procurement, maintenance and calibration of radiation detection instruments, and research and development support-services to the INEL and others. However, the existing facility was not originally designed for laboratory activities and does not provide an adequate, safe environment for calibration activities. The EA examined the potential environmental impacts of the proposed action and evaluated reasonable alternatives, including the no action alternative in accordance with the Council on Environmental Quality (CEQ) Regulations (40 CFR Parts 1500-1508). Based on the environmental analysis in the attached EA, the proposed action will not have a significant effect on the human environment within the meaning of the National Environmental Policy Act (NEPA) and 40 CFR Parts 1508.18 and 1508.27. The selected action (the proposed alternative) is composed of the following elements, each described or evaluated in the attached EA on the pages referenced. The proposed action is expected to begin in 1997 and will be completed within three years: design and construction of a new facility at the Central Facility Area of the INEL; operation of the facility, including instrument receipt, inspections and repairs, precision testing and calibration, and storage and issuance. The selected action will result in no significant environmental impacts

  14. A Good Name and Great Riches: Rebranding Solid State Physics for the National Laboratories

    Science.gov (United States)

    Martin, Joseph

    2012-03-01

    In 1943 Oliver Buckley, lamenting the inadequacy of term ``physics'' to evoke what physicists did, quoted the proverb, ``A good name is rather to be chosen than great riches.'' Some forty years later, solid state physicists confronted similar discontent with their name, precipitating the rise of the appellation ``condensed matter physics.'' Ostensibly a rebranding of a well-established field, the change signaled deeper conceptual and institutional realignment. Whereas ``solid state'' emerged in the 1940s in the service of institutional aims, ``condensed matter'' more accurately captured a distinct set of theoretical and experimental approaches. Reimagining the field around core conceptual approaches set condensed matter apart from the inchoate field of materials science, which subsumed a growing proportion of solid state funding and personnel through the 1980s. Federally funded research installations were the source of ``great riches'' for scientific research. The DOE National Laboratory System and the DARPA network of Interdisciplinary Laboratories, given their responsiveness to shifts in national funding priorities, provide a sensitive historical instrument through which to trace the transition from solid state to condensed matter. The reorganization of solid state in response to the evolution of national priorities and funding practices precipitated a sharpening of the field's intellectual mission. At the same time, it reflected the difficulties solid state faced articulating its intellectual--as opposed to technological--merit. The proverb continues, `` and loving favor rather than silver and gold.'' The adoption of a name that emphasized intellectual cohesion and associated social esteem exposed the growing tension between technology-oriented national funding goals for materials research and condensed matter physics' ascendant intellectual identity.

  15. Impact of National Physical Activity and Health Guidelines and Documents on Research on Teaching K-12 Physical Education in U.S.A.

    Science.gov (United States)

    Li, Weidong; Xiang, Ping; Gao, Zan; Shen, Bo; Yin, Zhihua; Kong, Qingtao

    2016-01-01

    Purpose: This study examined the impact of published national physical activity (PA) and health guidelines, documents, and initiatives on the evolution of research on teaching K-12 physical education (PE) in U.S.A. from 1996 to October 2013. Methods: A total of 262 peer-reviewed, data-based journal articles meeting our inclusion and exclusion…

  16. Physical activity, sedentary behavior, and body mass index in the Czech Republic: a nationally representative survey.

    Science.gov (United States)

    Mitáš, Josef; Ding, Ding; Frömel, Karel; Kerr, Jacqueline

    2014-07-01

    Post-communist countries have experienced rapid economic development and social changes, which have been accompanied by changes in health-related lifestyle behaviors, such as physical activity. The purpose of this study was to examine the associations of domain-specific physical activity and total sedentary time with BMI among adults in the Czech Republic. We surveyed a nationally representative sample (n = 4097) of the Czech Republic in fall 2007 using the International Physical Activity Questionnaire (long form). Multiple linear regression analyses were used to examine associations of physical activity, sedentary time and sociodemographic characteristics with BMI. Older age, lower educational attainment, and lower levels of leisure-time physical activity were associated with higher BMI. Compared with those living in large cities, men living in small towns and women living in small villages had higher BMI. This study has identified correlates of BMI in the Czech Republic. Although more evidence from longitudinal studies is needed, findings from the current study can inform interventions to prevent the rising obesity epidemic.

  17. Argonne National Laboratory Physics Division annual report, January--December 1996

    International Nuclear Information System (INIS)

    Thayer, K.J.

    1997-08-01

    The past year has seen several of the Physics Division's new research projects reach major milestones with first successful experiments and results: the atomic physics station in the Basic Energy Sciences Research Center at the Argonne Advanced Photon Source was used in first high-energy, high-brilliance x-ray studies in atomic and molecular physics; the Short Orbit Spectrometer in Hall C at the Thomas Jefferson National Accelerator (TJNAF) Facility that the Argonne medium energy nuclear physics group was responsible for, was used extensively in the first round of experiments at TJNAF; at ATLAS, several new beams of radioactive isotopes were developed and used in studies of nuclear physics and nuclear astrophysics; the new ECR ion source at ATLAS was completed and first commissioning tests indicate excellent performance characteristics; Quantum Monte Carlo calculations of mass-8 nuclei were performed for the first time with realistic nucleon-nucleon interactions using state-of-the-art computers, including Argonne's massively parallel IBM SP. At the same time other future projects are well under way: preparations for the move of Gammasphere to ATLAS in September 1997 have progressed as planned. These new efforts are imbedded in, or flowing from, the vibrant ongoing research program described in some detail in this report: nuclear structure and reactions with heavy ions; measurements of reactions of astrophysical interest; studies of nucleon and sub-nucleon structures using leptonic probes at intermediate and high energies; atomic and molecular structure with high-energy x-rays. The experimental efforts are being complemented with efforts in theory, from QCD to nucleon-meson systems to structure and reactions of nuclei. Finally, the operation of ATLAS as a national users facility has achieved a new milestone, with 5,800 hours beam on target for experiments during the past fiscal year

  18. Argonne National Laboratory Physics Division annual report, January--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Thayer, K.J. [ed.

    1997-08-01

    The past year has seen several of the Physics Division`s new research projects reach major milestones with first successful experiments and results: the atomic physics station in the Basic Energy Sciences Research Center at the Argonne Advanced Photon Source was used in first high-energy, high-brilliance x-ray studies in atomic and molecular physics; the Short Orbit Spectrometer in Hall C at the Thomas Jefferson National Accelerator (TJNAF) Facility that the Argonne medium energy nuclear physics group was responsible for, was used extensively in the first round of experiments at TJNAF; at ATLAS, several new beams of radioactive isotopes were developed and used in studies of nuclear physics and nuclear astrophysics; the new ECR ion source at ATLAS was completed and first commissioning tests indicate excellent performance characteristics; Quantum Monte Carlo calculations of mass-8 nuclei were performed for the first time with realistic nucleon-nucleon interactions using state-of-the-art computers, including Argonne`s massively parallel IBM SP. At the same time other future projects are well under way: preparations for the move of Gammasphere to ATLAS in September 1997 have progressed as planned. These new efforts are imbedded in, or flowing from, the vibrant ongoing research program described in some detail in this report: nuclear structure and reactions with heavy ions; measurements of reactions of astrophysical interest; studies of nucleon and sub-nucleon structures using leptonic probes at intermediate and high energies; atomic and molecular structure with high-energy x-rays. The experimental efforts are being complemented with efforts in theory, from QCD to nucleon-meson systems to structure and reactions of nuclei. Finally, the operation of ATLAS as a national users facility has achieved a new milestone, with 5,800 hours beam on target for experiments during the past fiscal year.

  19. Carrier concentration induced ferromagnetism in semiconductors

    International Nuclear Information System (INIS)

    Story, T.

    2007-01-01

    In semiconductor spintronics the key materials issue concerns ferromagnetic semiconductors that would, in particular, permit an integration (in a single multilayer heterostructure) of standard electronic functions of semiconductors with magnetic memory function. Although classical semiconductor materials, such as Si or GaAs, are nonmagnetic, upon substitutional incorporation of magnetic ions (typically of a few atomic percents of Mn 2+ ions) and very heavy doping with conducting carriers (at the level of 10 20 - 10 21 cm -3 ) a ferromagnetic transition can be induced in such diluted magnetic semiconductors (also known as semimagnetic semiconductors). In the lecture the spectacular experimental observations of carrier concentration induced ferromagnetism will be discussed for three model semiconductor crystals. p - Ga 1-x Mn x As currently the most actively studied and most perspective ferromagnetic semiconductor of III-V group, in which ferromagnetism appears due to Mn ions providing both local magnetic moments and acting as acceptor centers. p - Sn 1-x Mn x Te and p - Ge 1-x Mn x Te classical diluted magnetic semiconductors of IV-VI group, in which paramagnet-ferromagnet and ferromagnet-spin glass transitions are found for very high hole concentration. n - Eu 1-x Gd x Te mixed magnetic crystals, in which the substitution of Gd 3+ ions for Eu 2+ ions creates very high electron concentration and transforms antiferromagnetic EuTe (insulating compound) into ferromagnetic n-type semiconductor alloy. For each of these materials systems the key physical features will be discussed concerning: local magnetic moments formation, magnetic phase diagram as a function of magnetic ions and carrier concentration as well as Curie temperature and magnetic anisotropy engineering. Various theoretical models proposed to explain the effect of carrier concentration induced ferromagnetism in semiconductors will be briefly discussed involving mean field approaches based on Zener and RKKY

  20. Foreword: Focus on Superconductivity in Semiconductors

    Directory of Open Access Journals (Sweden)

    Yoshihiko Takano

    2008-01-01

    Full Text Available Since the discovery of superconductivity in diamond, much attention has been given to the issue of superconductivity in semiconductors. Because diamond has a large band gap of 5.5 eV, it is called a wide-gap semiconductor. Upon heavy boron doping over 3×1020 cm−3, diamond becomes metallic and demonstrates superconductivity at temperatures below 11.4 K. This discovery implies that a semiconductor can become a superconductor upon carrier doping. Recently, superconductivity was also discovered in boron-doped silicon and SiC semiconductors. The number of superconducting semiconductors has increased. In 2008 an Fe-based superconductor was discovered in a research project on carrier doping in a LaCuSeO wide-gap semiconductor. This discovery enhanced research activities in the field of superconductivity, where many scientists place particular importance on superconductivity in semiconductors.This focus issue features a variety of topics on superconductivity in semiconductors selected from the 2nd International Workshop on Superconductivity in Diamond and Related Materials (IWSDRM2008, which was held at the National Institute for Materials Science (NIMS, Tsukuba, Japan in July 2008. The 1st workshop was held in 2005 and was published as a special issue in Science and Technology of Advanced Materials (STAM in 2006 (Takano 2006 Sci. Technol. Adv. Mater. 7 S1.The selection of papers describe many important experimental and theoretical studies on superconductivity in semiconductors. Topics on boron-doped diamond include isotope effects (Ekimov et al and the detailed structure of boron sites, and the relation between superconductivity and disorder induced by boron doping. Regarding other semiconductors, the superconducting properties of silicon and SiC (Kriener et al, Muranaka et al and Yanase et al are discussed, and In2O3 (Makise et al is presented as a new superconducting semiconductor. Iron-based superconductors are presented as a new series of high

  1. Argonne National Laboratory, High Energy Physics Division: Semiannual report of research activities, July 1, 1986-December 31, 1986

    International Nuclear Information System (INIS)

    1987-01-01

    This paper discusses the research activity of the High Energy Physics Division at the Argonne National Laboratory for the period, July 1986-December 1986. Some of the topics included in this report are: high resolution spectrometers, computational physics, spin physics, string theories, lattice gauge theory, proton decay, symmetry breaking, heavy flavor production, massive lepton pair production, collider physics, field theories, proton sources, and facility development

  2. Clinical reasoning of Filipino physical therapists: Experiences in a developing nation.

    Science.gov (United States)

    Rotor, Esmerita R; Capio, Catherine M

    2018-03-01

    Clinical reasoning is essential for physical therapists to engage in the process of client care, and has been known to contribute to professional development. The literature on clinical reasoning and experiences have been based on studies from Western and developed nations, from which multiple influencing factors have been found. A developing nation, the Philippines, has distinct social, economic, political, and cultural circumstances. Using a phenomenological approach, this study explored experiences of Filipino physical therapists on clinical reasoning. Ten therapists working in three settings: 1) hospital; 2) outpatient clinic; and 3) home health were interviewed. Major findings were: a prescription-based referral system limited clinical reasoning; procedural reasoning was a commonly experienced strategy while diagnostic and predictive reasoning were limited; factors that influenced clinical reasoning included practice setting and the professional relationship with the referring physician. Physical therapists' responses suggested a lack of autonomy in practice that appeared to stifle clinical reasoning. Based on our findings, we recommend that the current regulations governing PT practice in the Philippines may be updated, and encourage educators to strengthen teaching approaches and strategies that support clinical reasoning. These recommendations are consistent with the global trend toward autonomous practice.

  3. Sector activities and lessons learned around initial implementation of the United States national physical activity plan.

    Science.gov (United States)

    Evenson, Kelly R; Satinsky, Sara B

    2014-08-01

    National plans are increasingly common but infrequently evaluated. The 2010 United States National Physical Activity Plan (NPAP) provided strategies to increase population levels of physical activity. This paper describes (i) the initial accomplishments of the NPAP sector teams, and (ii) results from a process evaluation to determine how the sectors operated, their cross-sector collaboration, challenges encountered, and positive experiences. During 2011, a quarterly reporting system was developed to capture sector-level activities. A year-end interview derived more detailed information. Interviews with 12 sector leads were recorded, transcribed verbatim, and analyzed for common themes. The 6 sectors worked on goals from the implementation plan that focused broadly on education, promotion, intervention, policy, collaboration, and evaluation. Through year-end interviews, themes were generated around operations, goal setting, and cross-sector collaboration. Challenges to the NPAP work included lack of funding and time, the need for marketing and promotion, and organizational support. Positive experiences included collaboration, efficiency of work, enhanced community dynamic, and accomplishments toward NPAP goals. These initial results on the NPAP sector teams can be used as a baseline assessment for future monitoring. The lessons learned may be useful to other practitioners developing evaluations around state- or national-level plans.

  4. Semiconductors data handbook

    CERN Document Server

    Madelung, Otfried

    2004-01-01

    This volume Semiconductors: Data Handbook contains frequently used data from the corresponding larger Landolt-Börnstein handbooks in a low price book for the individual scientist working in the laboratory. The Handbook contain important information about a large number of semiconductors

  5. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  6. Terahertz semiconductor nonlinear optics

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias

    2013-01-01

    In this proceedings we describe our recent results on semiconductor nonlinear optics, investigated using single-cycle THz pulses. We demonstrate the nonlinear absorption and self-phase modulation of strong-field THz pulses in doped semiconductors, using n-GaAs as a model system. The THz...... nonlinearity in doped semiconductors originates from the near-instantaneous heating of free electrons in the ponderomotive potential created by electric field of the THz pulse, leading to ultrafast increase of electron effective mass by intervalley scattering. Modification of effective mass in turn leads...... to a decrease of plasma frequency in semiconductor and produces a substantial modification of THz-range material dielectric function, described by the Drude model. As a result, the nonlinearity of both absorption coefficient and refractive index of the semiconductor is observed. In particular we demonstrate...

  7. Small-polaron formation and motion in magnetic semiconductors

    International Nuclear Information System (INIS)

    Emin, D.

    1979-01-01

    The fundamental physical processes associated with small-polaron formation are described with various magnetic semi-conductors being cited as examples. Attention is then directed toward the mechanisms of charge transfer and small-polaron hopping motion in magnetic semiconductors

  8. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap semiconductor (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas. (author). 7 refs

  9. The features of modelling semiconductor lasers with a wide contact

    Directory of Open Access Journals (Sweden)

    Rzhanov Alexey

    2017-01-01

    Full Text Available The aspects of calculating the dynamics and statics of powerful semiconductor laser diodes radiation are investigated. It takes into account the main physical mechanisms influencing power, spectral composition, far and near field of laser radiation. It outlines a dynamic distributed model of a semiconductor laser with a wide contact and possible algorithms for its implementation.

  10. Tight-Binding Description of Impurity States in Semiconductors

    Science.gov (United States)

    Dominguez-Adame, F.

    2012-01-01

    Introductory textbooks in solid state physics usually present the hydrogenic impurity model to calculate the energy of carriers bound to donors or acceptors in semiconductors. This model treats the pure semiconductor as a homogeneous medium and the impurity is represented as a fixed point charge. This approach is only valid for shallow impurities…

  11. The Modulation Response of a Semiconductor Laser Amplifier

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, Antonio; Eisenstein, Gadi

    1999-01-01

    We present a theoretical analysis of the modulation response of a semiconductor laser amplifier. We find a resonance behavior similar to the well-known relaxation oscillation resonance found in semiconductor lasers, but of a different physical origin. The role of the waveguide (scattering) loss i...

  12. Theoretical models of ferromagnetic III-V semiconductors

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Tomáš; Sinova, J.; Kučera, Jan; MacDonald, A. H.

    2003-01-01

    Roč. 3, - (2003), s. 461-464 ISSN 1567-1739. [Mesoscopic Electronics COST Workshop. Catania, 16.10.2002-19.10.2002] Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * diluted magnetic semiconductors * magneto-transport Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.117, year: 2002

  13. National Study of Excellence and Innovation in Physical Therapist Education: Part 1-Design, Method, and Results.

    Science.gov (United States)

    Jensen, Gail M; Nordstrom, Terrence; Mostrom, Elizabeth; Hack, Laurita M; Gwyer, Janet

    2017-09-01

    The Carnegie Foundation for the Advancement of Teaching commissioned the Preparation for the Professions Program, a qualitative study of professional education in 5 professions: medicine, nursing, law, engineering, and clergy. These studies identified curricular structures, instructional practices, assessment approaches, and environmental characteristics that support the preparation of professionals and led to educational reforms. The physical therapy profession has not had any in-depth, national investigation of physical therapist education since the Catherine Worthingham studies conducted more than 50 years ago. This research was a Carnegie-type study, investigating elements of excellence and innovation in academic and clinical physical therapist education in the United States. Five physical therapist education researchers from across the United States used a qualitative multiple-case study design. Six academic and 5 clinical programs were selected for the study. The academic institutions and clinical agencies studied were diverse in size, institutional setting, geography, and role in residency education. Qualitative case studies were generated from review of artifacts, field observations, and interviews (individual and focus group), and they provided the data for the study. A conceptual framework grounded in 3 major dimensions was generated, with 8 supporting elements: (1) culture of excellence (shared beliefs and values, leadership and vision, drive for excellence, and partnerships), (2) praxis of learning (signature pedagogy, practice-based learning, creating adaptive learners, and professional formation), and (3) organizational structures and resources. Building on the work of the Carnegie Foundation's Preparation for the Professions Program, a conceptual model was developed, representing the dimensions and elements of excellence in physical therapist education that is centered on the foundational importance of a nexus of linked and highly valued aims of

  14. Radiological, physical, and chemical characterization of transuranic wastes stored at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Apel, M.L.; Becker, G.K.; Ragan, Z.K.; Frasure, J.; Raivo, B.D.; Gale, L.G.; Pace, D.P.

    1994-03-01

    This document provides radiological, physical and chemical characterization data for transuranic radioactive wastes and transuranic radioactive and hazardous (i.e., mixed) wastes stored at the Idaho National Engineering Laboratory and considered for treatment under the Private Sector Participation Initiative Program (PSPI). Waste characterization data are provided in the form of INEL Waste Profile Sheets. These documents provide, for each content code, information on waste identification, waste description, waste storage configuration, physical/chemical waste composition, radionuclide and associated alpha activity waste characterization data, and hazardous constituents present in the waste. Information is provided for 139 waste streams which represent an estimated total volume of 39,380 3 corresponding to a total mass of approximately 19,000,000 kg. In addition, considerable information concerning alpha, beta, gamma, and neutron source term data specific to Rocky Flats Plant generated waste forms stored at the INEL are provided to assist in facility design specification

  15. Charge regulation at semiconductor-electrolyte interfaces.

    Science.gov (United States)

    Fleharty, Mark E; van Swol, Frank; Petsev, Dimiter N

    2015-07-01

    The interface between a semiconductor material and an electrolyte solution has interesting and complex electrostatic properties. Its behavior will depend on the density of mobile charge carriers that are present in both phases as well as on the surface chemistry at the interface through local charge regulation. The latter is driven by chemical equilibria involving the immobile surface groups and the potential determining ions in the electrolyte solution. All these lead to an electrostatic potential distribution that propagate such that the electrolyte and the semiconductor are dependent on each other. Hence, any variation in the charge density in one phase will lead to a response in the other. This has significant implications on the physical properties of single semiconductor-electrolyte interfaces and on the electrostatic interactions between semiconductor particles suspended in electrolyte solutions. The present paper expands on our previous publication (Fleharty et al., 2014) and offers new results on the electrostatics of single semiconductor interfaces as well as on the interaction of charged semiconductor colloids suspended in electrolyte solution. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. The health physics program at the National Bureau of Standards LINAC

    International Nuclear Information System (INIS)

    Hobbs, T.G.

    1981-01-01

    A three-person Accelerator Health Physics team provides continuous radiation safety service for the National Bureau of Standards 150-MeV linear electron accelerator (Linac), which operates on a five days per week, 24 hours per day schedule, with one day per month downtime scheduled for maintenance. This team also serves the synchrotron ultraviolet light radiation facility (SURF), two Van de Graaffs, some other electrostatic accelerators, and several high-energy x-ray generators. Although the Linac is not licensed by a safety-regulating agency, as is the NBS Research Reactor, Health Physics makes no distinction between the two sources in providing coverage. Various regulations do impact on operations, e.g., the NRC dose totals and effluent releases and the OSHA requirements. Film, thermoluminescent dosimeters (TLD), and direct-reading pocket dosimeters are used for personnel dosimetry. The usual array of portable and fixed radiation survey meters and activation devices and some of the high-energy multi-particle activation techniques are used for area monitoring. Environmental surveillance is performed with TLD's, tissue-equivalent ion chamber, and a grass and soil assay program. Integrated Health Physics programs for all the NBS radiation facilities do instrument calibrations, training for Health Physics and operating staffs, administrative control of radioactive materials, waste management, and data compilations

  17. The work of physical education professionals in Family Health Support Centers (NASF: a national survey

    Directory of Open Access Journals (Sweden)

    Sueyla Ferreira da Silva dos Santos

    2015-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n6p693   This is a descriptive and quantitative national survey aimed at presenting Health Education practices (HE developed by Physical Education professionals working at NASF in Brazil. Overall, 296 professionals participated in this study, stratified by Brazilian regions and NASF groupings. Electronic interviews were conducted regarding the activities developed at the unity where each NASF professional worked. The main activities reported were gymnastics (40.1%, and walking (29.4%, having as their priority public elderly people (68.8%, groups of hypertensive and diabetic patients (30.9% and young people (48.3%, respectively. The most discussed topics in lectures and orientations was the importance of physical activity (51.4% and the second most cited was the prevention/treatment of comorbities (32.3%. The community spaces most utilized by Physical Education professionals to develop activities were: public squares, community centers and schools in the southeastern and southern regions of Brazil, and religious entities in the northeastern and Midwestern regions. In conclusion, in spite of the diversity of activities developed in different regions of Brazil, there is predominance of traditional Physical Education contents, which reflect the need of permanent education of such professionals to improve the quality of services offered to the community.

  18. Utilization of the national Portland cement for immobilizing radioactive wastes - Physical characteristics

    International Nuclear Information System (INIS)

    Rzyski, B.M.; Suarez, A.A.

    1988-01-01

    This paper shows the results obtained in the study of the national Portland cement, P320, as matrix for radioactive nitric waste incorporation. Cement use practice in other countries is common for this purposes and demonstrates to be cheap and accessible when low and medium level wastes are immobilized. Some of physical characteristics as: homogeneity,mechanical strenght, setting and porosity are analysed due to water-cement ratio and salt contents. Those characteristics which are proper of the final product, must be controlled in such way to assure a long time integrity of the wasteform. The establishment of process and quality control criteria are based in such kind of data. (author) [pt

  19. Physics education of Japanese national colleges of technology in local community of Hokkaido

    Science.gov (United States)

    Kushino, Akihiro; Matsui, Hidenori

    2014-03-01

    The national colleges of technology in Japan, called KOSEN, were established about 50 years ago aiming to educate 15 to 20 years old students to become engineers who were necessary in period of high economic growth of Japan. In present, environment surrounding us has changed. Examples are low birth rate in Japan and the great earthquake in Tohoku area. There are 4 KOSENs in Hokkaido and we jointly make many efforts to contribute to local community in science. We present our efforts in physics education.

  20. Operational health and physics service during the maintenance of the Australian National Medical Cyclotron

    International Nuclear Information System (INIS)

    Mukherjee, B.

    1994-01-01

    Modern Medical Cyclotrons use intense beams of high energy protons or deuterons to produce large activities of short and medium lived radionuclides. After continuous operation for prolonged periods the Cyclotron components become activated through various nuclear interactions therefore, the risk of personal radiation hazard while handling such activated cyclotron components is high. This paper describes all operational aspects of the Health Physics service evolved during the first preventative maintenance program of the Australian National Medical Cyclotron, which took place in June 1993. 5 refs., 3 tabs., 2 figs

  1. Sexuality and physical contact in National Social Life, Health, and Aging Project Wave 2.

    Science.gov (United States)

    Galinsky, Adena M; McClintock, Martha K; Waite, Linda J

    2014-11-01

    Wave 2 of the National Social Life, Health, and Aging Project (NSHAP) includes new measures of sexual interest and behavior, as well as new measures of the context of sexual experience and the frequency and appeal of physical contact. This is the first time many of these constructs have been measured in a nationally representative sample. We describe the new measures and compare the distributions of each across gender and age groups, in some cases by partnership status. Two components of sexuality decrease with age among both men and women: frequency of finding an unknown person sexually attractive and receptivity to a partner's sexual overtures. In contrast, the inclination to make one's self sexually attractive to others was a more complicated function of partner status, gender, and age: partnered women and unpartnered men made the most effort, with the more effortful gender's effort decreasing with age. Both men and women find nonsexual physical contact appealing but sexual physical contact is more appealing to men than women. Finally, two fifths of men and women report dissatisfaction with their partner's frequency of caring behaviors that make later sexual interactions pleasurable, and a fifth of women and a quarter of men who had vaginal sex in the past year report dissatisfaction with amount of foreplay. These data offer the opportunity to characterize sexual motivation in older adulthood more precisely and richly and to examine how the context of sexual experience and the nonsexual aspects of physical intimacy correlate with sexual behavior, enjoyment, and problems. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Quantum theory of the optical and electronic properties of semiconductors

    CERN Document Server

    Haug, Hartmut

    2009-01-01

    This invaluable textbook presents the basic elements needed to understand and research into semiconductor physics. It deals with elementary excitations in bulk and low-dimensional semiconductors, including quantum wells, quantum wires and quantum dots. The basic principles underlying optical nonlinearities are developed, including excitonic and many-body plasma effects. Fundamentals of optical bistability, semiconductor lasers, femtosecond excitation, the optical Stark effect, the semiconductor photon echo, magneto-optic effects, as well as bulk and quantum-confined Franz-Keldysh effects, are covered. The material is presented in sufficient detail for graduate students and researchers with a general background in quantum mechanics.This fifth edition includes an additional chapter on 'Quantum Optical Effects' where the theory of quantum optical effects in semiconductors is detailed. Besides deriving the 'semiconductor luminescence equations' and the expression for the stationary luminescence spectrum, the resu...

  3. Argonne National Laboratory High Energy Physics Division semiannual report of research activities, January 1, 1989--June 30, 1989

    International Nuclear Information System (INIS)

    1989-01-01

    This paper discuss the following areas on High Energy Physics at Argonne National Laboratory: experimental program; theory program; experimental facilities research; accelerator research and development; and SSC detector research and development

  4. Some physical properties of GaX (X=P, As and Sb) semiconductor compounds using higher-order perturbation theory

    International Nuclear Information System (INIS)

    Jivani, A.R.; Trivedi, H.J.; Gajjar, P.N.; Jani, A.R.

    2005-01-01

    Recently proposed model potential for describing the electron-ion interaction is employed to calculate total energy, energy band gap at Jones-zone face at X, equation of state and bulk modulus of GaP, GaAs and GaSb compounds using higher-order perturbation theory. The covalent correction term corresponding to third- and fourth-order perturbation energy terms are used to take account of covalent bonding effect in such semiconductors. The significant value of the covalent bonding term shows the essentiality of higher-order correction for zincblende-type crystals. We have employed five different screening functions along with the latest screening function proposed by Sarkar et al. in the present work. The numerical results for the total energy, energy band gap at Jones-zone face and bulk modulus of these compounds are in good agreement with the experimental data and found better than other such theoretical findings. The pressure and bulk modulus at different volumes are obtained by using such higher-order perturbation theory with the application of our model potential. The pressure obtained by this method is compared with pressure obtained by equations proposed by Murnarghan and Vinet et al. The present study also shows that the incorporation of different screening functions generates distinct effects

  5. The role of the National Physical Laboratory in monitoring and improving dosimetry in UK radiotherapy

    International Nuclear Information System (INIS)

    Thomas, R.A.S.; Duane, S.; McEwen, M.R.; Rosser, K.E.

    2002-01-01

    In the UK, the National Physical Laboratory, in collaboration with the Institute for Physics and Engineering in Medicine operates an audit programme to ensure national consistency in radiotherapy dosimetry. The present programme covers dosimetry of megavoltage photons and electrons (3-19 MeV) and low and medium energy (10-300 kV) photons. The aim of each audit is to verify the local measurement of absorbed dose at the radiotherapy centre. The audit measurements - principally beam quality and linac output - are made following the same protocol as the clinic but using different equipment. The audit is not an absolute measurement of the absorbed dose but amounts to a check that the equipment used by the centre is operating as expected and that the Code of Practice is being followed correctly. The protocols used in the UK are IPSM 1990 for high-energy photons, IPEMB 1996 for electrons and IPEMB 1996 for low energy photons. For the purpose of these audits, NPL maintains a set of calibrated ionisation chambers

  6. The National Spherical Tokamak Experiment at the Princeton Plasma Physics Laboratory

    International Nuclear Information System (INIS)

    1995-12-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1108, evaluating the environmental effects of the proposed construction and operation of the National Spherical Tokamak Experiment (NSTX) within the existing C-Stellarator (CS) Building at the Princeton Plasma Physics Laboratory, Princeton, New Jersey. The purpose of the NSTX is to investigate the physics of spherically shaped plasmas as an alternative path to conventional tokamaks for development of fusion energy. Fusion energy has the potential to help compensate for dwindling supplies of fossil fuels and the eventual depletion of fissionable uranium used in present-day nuclear reactors. Construction of the NSTX in the CS Building would require the dismantling and removal of the existing unused Princeton Large Torus (PLT) device, part of which would be reused to construct the NSTX. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 U.S.C. 4,321 et seq. The preparation of an Environmental Impact Statement is not required. Thus, the DOE is issuing a FONSI pursuant to the Council on Environmental Quality regulations implementing NEPA (40 CFR Parts 1500--1508) and the DOE NEPA implementing regulations (10 CFR Part 1021)

  7. [Physical activities and health: results of a national survey of workers].

    Science.gov (United States)

    Simon-Rigaud, M L

    1995-10-01

    Since 15 years, the ASMT (Association for the promotion of sports in enterprises) has been trying to demonstrate that physical activities is a health factor for workers and their enterprises. Few studies (1980-1990) in individual enterprises (Alsthom, IBM, Aérospatiale, Peugeot...), and a national one (1985, 1,600 sportsmen) have shown the relationship between exercise and a lower absenteeism. These results were confirmed by a randomized national controlled study in 1990-1991. With the assistance of 115 work-doctors, the ASMT included more than 22,000 workers: 38% of them had physical activities (ASMT 1: 1 hour a week, ASMT 2: 3 hours a week, ASMT 3: competitors), and 62% had none. Exercisers have less industrial injuries than sedentary people (3.78% vs 4.52%. p. < 0.001) and less absences for illness (26.4% vs 30.8%. p. < 0.001). The duration of their absences are shorter for industrial injuries (sedentary people: 27.9 days, ASMT 1: 27.1 days, ASMT 2: 25.5 days, ASMT 3: 24.6 days) and for illness (sedentary people: 23.6 days, ASMT 1: 19.1 days, ASMT 2: 17.4 days, ASMT 3: 15.3 days).

  8. Defects in semiconductors

    International Nuclear Information System (INIS)

    Pimentel, C.A.F.

    1983-01-01

    Some problems openned in the study of defects in semiconductors are presented. In particular, a review is made of the more important problems in Si monocrystals of basic and technological interest: microdefects and the presence of oxigen and carbon. The techniques usually utilized in the semiconductor material characterization are emphatized according its potentialities. Some applications of x-ray techniques in the epitaxial shell characterization in heterostructures, importants in electronic optics, are shown. The increase in the efficiency of these defect analysis methods in semiconductor materials with the use of synchrotron x-ray sources is shown. (L.C.) [pt

  9. Introduction to Semiconductor Devices

    Science.gov (United States)

    Brennan, Kevin F.

    2005-03-01

    This volume offers a solid foundation for understanding the most important devices used in the hottest areas of electronic engineering today, from semiconductor fundamentals to state-of-the-art semiconductor devices in the telecommunications and computing industries. Kevin Brennan describes future approaches to computing hardware and RF power amplifiers, and explains how emerging trends and system demands of computing and telecommunications systems influence the choice, design and operation of semiconductor devices. In addition, he covers MODFETs and MOSFETs, short channel effects, and the challenges faced by continuing miniaturization. His book is both an excellent senior/graduate text and a valuable reference for practicing engineers and researchers.

  10. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  11. The effects of heavy doping on the electronic states in semiconductors

    International Nuclear Information System (INIS)

    Sernelius, B.E.

    1987-01-01

    The physics of semiconductors is reviewed. Topics included in the discussion are energy of the dopant system (kinetic energy in a many-valley semiconductor, exchange energy in an ellipsoidal Fermi volume, energy in a polar semiconductor), self energy shifts, band-gap narrowing, and piezo experiments. 31 refs., 27 figs

  12. Tunneling of electrons through semiconductor superlattices

    Indian Academy of Sciences (India)

    Unknown

    Tunneling of electrons through semiconductor superlattices. C L ROY. Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, India. Abstract. The purpose of the present paper is to report a study of tunneling of electrons through semicon- ductor superlattices (SSL); specially, we have ...

  13. ON THE ARTIFICIAL SEMICONDUCTOR MATERIALS | Adelabu ...

    African Journals Online (AJOL)

    For about the last three decades, semiconductor technology began to make its most apparent impact in Solid State Electronics. The field of photonics, which combines laser physics, electro-optics and nonlinear optics has expanded tremendously. Notably, modern light wave communications exemplify photonic systems.

  14. Collective spin fluctuations in diluted magnetic semiconductors

    Czech Academy of Sciences Publication Activity Database

    König, J.; Schliemann, J.; Jungwirth, Tomáš; MacDonald, A. H.

    2002-01-01

    Roč. 12, - (2002), s. 379-382 ISSN 1386-9477 Institutional research plan: CEZ:AV0Z1010914 Keywords : spin fluctuation * magnetic semiconductors Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.107, year: 2002

  15. Ferromagnetism in diluted magnetic semiconductor heterojunction systems

    Czech Academy of Sciences Publication Activity Database

    Lee, B.; Jungwirth, Tomáš; MacDonald, A. H.

    2002-01-01

    Roč. 17, - (2002), s. 393-403 ISSN 0268-1242 R&D Projects: GA ČR GA202/98/0085; GA MŠk OC P5.10 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * heterostructures Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.241, year: 2002

  16. Comment on The Rise of Semiconductor Spintronics

    OpenAIRE

    Korenev, Vladimir L.

    2009-01-01

    I argue that most of the key experiments that have born semiconductor spintronics were done and published earlier than the papers cited in the Nature Physics, 4 S20 (2008) milestone article (http://www.nature.com/milestones/spin, milestone 23).

  17. Physical protection as the most important part of the national system of combating illicit trafficking

    International Nuclear Information System (INIS)

    Mishchenko, V.

    2002-01-01

    Full text: It is now obvious today that illicit trafficking, including its most dangerous manifestations proliferation of nuclear weapons, smuggling of nuclear materials and equipment - present a serious threat to the international community. To defeat this evil is possible only by joint efforts, by undertaken protective measures on national and international level. Joint efforts should be directed at fulfilling three main tasks as follows: safe and reliable handling of nuclear material, effective measures of its physical protection, accountancy and control in order to prevent proliferation; joint activities of intelligence customs and law-enforcement authorities directed at prevention of international trafficking and marketing of stolen goods; joint activities directed at identification and prevention of illegal supply and demand of fissionable materials counteracting thereby various criminal structures. In order to solve these problems an international regime should be established. Such regime will define a number of criteria and demands to be met by-the states to ensure effective combat illicit trafficking. The international regime should be based on national systems of combating illicit trafficking, which include measures for prevention, detection and response regarding illicit trafficking in each specific state of across its borders. When undertaking these measures one should take into account specific characteristics of the state, its unique features and its geography, political and economic situation, as well as different types of potential threat of proliferation of nuclear weapons; availability of materials subjected to illicit trafficking in this state, general situation of criminal trafficking in this state, general situation of criminal trafficking with radioactive materials, potential consumers and suppliers, market features, possible incentives for crime etc. In the paper I would like to reflect the vital components of national systems for combating

  18. A survey of the high energy physics program at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Hahn, H.; Rau, R.R.; Wanderer, P.

    1977-01-01

    About fifteen years ago the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory began operating for high energy particle physics experiments. A wealth of important results has been published, capped by four discoveries which have changed the field dramatically. These discoveries are: the muon neutrino, γsub(μ); the strangeness minus three Ω - baryon; CP violation in K 0 decay; and recently the totally unpredicted J/psi particle. The experimental program has broadened, matured and increased in scope following a large improvement program at the AGS. Major developments included: replacement of the original 50 MeV linear accelerator injector by a modern 200 MeV linac; construction of two new experimental areas, one for neutrino experiments and the other for counter-spark chamber electronics experiments, with the philosophy that nearly all circulating protons would be extracted from the machine and directed onto targets external to the machine; raising the circulating proton intensity to a maximum of 10 13 protons, and installation of a new magnet supply allowing a cycle of 2.4 seconds with a 1 second flat-top, or a 40% duty cycle. The paper also describes a crucial function of any particle physics laboratory, the plans and research directed toward new facilities to make available new regions for particle physics research. (Auth.)

  19. Smoking, physical exercise, BMI and late foetal death: a study within the Danish National Birth Cohort.

    Science.gov (United States)

    Morales-Suárez-Varela, Maria; Nohr, Ellen A; Bech, Bodil H; Wu, Chunsen; Olsen, Jørn

    2016-10-01

    The aim of this paper was to estimate the effect of maternal and paternal smoking on foetal death (miscarriage and stillbirth) and to estimate potential interactions with physical exercise and pre-pregnancy body mass index. We selected 87,930 pregnancies from the population-based Danish National Birth Cohort. Information about lifestyle, occupational, medical and obstetric factors was obtained from a telephone interview and data on pregnancy outcomes came from the Danish population based registries. Cox regression was used to estimate the hazard ratios (adjusted for potential confounders) for predominantly late foetal death (miscarriage and stillbirth). An interaction contrast ratio was used to assess potential effect measure modification of smoking by physical exercise and body mass index. The adjusted hazard ratio of foetal death was 1.22 (95 % CI 1.02-1.46) for couples where both parents smoked compared to non-smoking parents (miscarriage: 1.18, 95 % CI 0.96-1.44; stillbirth: 1.32, 95 % CI 0.93-1.89). On the additive scale, we detected a small positive interaction for stillbirth between smoking and body mass index (overweight women). In conclusion, smoking during pregnancy was associated with a slightly higher hazard ratio for foetal death if both parents smoked. This study suggests that smoking may increase the negative effect of a high BMI on foetal death, but results were not statistically significant for the interaction between smoking and physical exercise.

  20. Improved physical fitness among older female participants in a nationally disseminated, community-based exercise program.

    Science.gov (United States)

    Seguin, Rebecca A; Heidkamp-Young, Eleanor; Kuder, Julia; Nelson, Miriam E

    2012-04-01

    Strength training (ST) is an important health behavior for aging women; it helps maintain strength and function and reduces risk for chronic diseases. This study assessed change in physical fitness following participation in a ST program implemented and evaluated by community leaders. The StrongWomen Program is a nationally disseminated, research-based, community ST program active in 40 states. The Senior Fitness Test is used to assess upper and lower body strength, upper and lower body flexibility, aerobic fitness, and agility; data are collected prior to and following program participation. For these analyses, five states provided deidentified data for 367 female participants, mean age 63 (±11) years. Attendance in approximately 10 weeks of twice-weekly classes was 69.4%. Paired t tests were used to analyze pre-post change. Significant improvements were observed (p age-group and compared with published, age-based norms. This study demonstrates that it is feasible for community leaders to conduct pre-post physical fitness evaluations with participants and that participants experienced improvements across several important domains of physical fitness.

  1. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  2. Association between Physical Abuse, Physical Neglect and Health Risk Behaviours among Young Adolescents: Results from the National Study

    Directory of Open Access Journals (Sweden)

    Dimitrinka Jordanova Peshevska

    2014-06-01

    CONCLUSION: The results demonstrated a relationship between physical abuse and later manifestation of health risk behaviours such as: smoking and early pregnancy. Physical neglect increased the chances for drug abuse, drink-driving, having early sex, having more sexual partners.

  3. National approaches to promote sports and physical activity in adults with disabilities: examples from the Netherlands and Canada.

    Science.gov (United States)

    Hoekstra, Femke; Roberts, Lynn; van Lindert, Caroline; Martin Ginis, Kathleen A; van der Woude, Lucas H V; McColl, Mary Ann

    2018-01-15

    This study described how the Dutch and Canadian governments promote high performance sports, recreational sports, and physical activity (PA) among adults with disabilities on a national level. An internet-based study was conducted to identify and select relevant documents and websites containing information about the national approach to promote disability sports and physical activities in the Netherlands and Canada. Both governments promote high performance sports in similar ways, but use different strategies to promote recreational sports and physical activities. The Dutch approach is characterized by using time-limited programs focusing on enhancement of sports infrastructure and inter-sector collaboration in which municipalities have key roles. The Canadian government promotes recreational sports in disabled populations by supporting programs via bilateral agreements with provinces and territories. Furthermore, the level of integration of disability sports into mainstream sports differs between countries. The findings of this study may inspire policy makers from different countries to learn from one another's policies in order to optimize national approaches to promote disability sports and PA on all levels. Implications for rehabilitation It is recommended for policy makers of national governments to develop and implement policy programs that promote sports and physical activities among people with disabilities because of its potential impact on functioning, participation, quality of life, and health. Insight into national approaches to promote sport and physical activities is relevant for rehabilitation practice to understand ongoing opportunities for people with disabilities to stay physically active after rehabilitation through participation in home and/or community-based sport and physical activities. It seems worthwhile to integrate activities to promote sport and physical activities in rehabilitation in such a way that it fits with the current

  4. Identification of Spatial Fault Patterns in Semiconductor Wafers

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract The semiconductor industry is constantly searching for new ways to increase the rate of both process development and yield learning. As more data is being...

  5. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  6. Market survey of semiconductors

    International Nuclear Information System (INIS)

    Mackintosh, I.M.; Diegel, D.; Brown, A.; Brinker, C.S. den

    1977-06-01

    Examination of technology and product trends over the range of current and future products in integrated circuits and optoelectronic displays. Analysis and forecast of major economic influences that affect the production costs of integrated circuits and optoelectronic displays. Forecast of the applications and markets for integrated circuits up to 1985 in West Europe, the USA and Japan. Historic development of the semiconductor industry and the prevailing tendencies - factors which influence success in the semiconductor industry. (orig.) [de

  7. Electronic properties of semiconductor heterostructures

    International Nuclear Information System (INIS)

    Einevoll, G.T.

    1991-02-01

    Ten papers on the electronic properties of semiconductors and semiconductor heterostructures constitute the backbone of this thesis. Four papers address the form and validity of the single-band effective mass approximation for semiconductor heterostructures. In four other papers properties of acceptor states in bulk semiconductors and semiconductor heterostructures are studied using the novel effective bond-orbital model. The last two papers deal with localized excitions. 122 refs

  8. III-V semiconductor materials and devices

    CERN Document Server

    Malik, R J

    1989-01-01

    The main emphasis of this volume is on III-V semiconductor epitaxial and bulk crystal growth techniques. Chapters are also included on material characterization and ion implantation. In order to put these growth techniques into perspective a thorough review of the physics and technology of III-V devices is presented. This is the first book of its kind to discuss the theory of the various crystal growth techniques in relation to their advantages and limitations for use in III-V semiconductor devices.

  9. Exploring carrier dynamics in semiconductors for slow light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Xue, Weiqi; Chen, Yaohui

    2009-01-01

    We give an overview of recent results on slow and fast light in active semiconductor waveguides. The cases of coherent population oscillations as well as electromagnetically induced transparency are covered, emphasizing the physics and fundamental limitations.......We give an overview of recent results on slow and fast light in active semiconductor waveguides. The cases of coherent population oscillations as well as electromagnetically induced transparency are covered, emphasizing the physics and fundamental limitations....

  10. Transient electro-thermal modeling of bipolar power semiconductor devices

    CERN Document Server

    Gachovska, Tanya Kirilova; Du, Bin

    2013-01-01

    This book presents physics-based electro-thermal models of bipolar power semiconductor devices including their packages, and describes their implementation in MATLAB and Simulink. It is a continuation of our first book Modeling of Bipolar Power Semiconductor Devices. The device electrical models are developed by subdividing the devices into different regions and the operations in each region, along with the interactions at the interfaces, are analyzed using the basic semiconductor physics equations that govern device behavior. The Fourier series solution is used to solve the ambipolar diffusio

  11. AMS at the National Institute of Nuclear Physics and Engineering in Bucharest

    International Nuclear Information System (INIS)

    Stan-Sion, C.; Ivascu, M.; Plostinaru, D.; Catana, D.; Marinescu, L.; Radulescu, M.; Nolte, E.

    2000-01-01

    A new beam line and injector deck for AMS measurements have been built at the 8 MV tandem accelerator of the National Institute of Nuclear Physics and Engineering, Bucharest, Romania. The main components on the low-energy side are a high-current cesium sputter source, a 90 deg. injection magnet and a pre-acceleration stage. At the high-energy side the beam line is achromatic, consisting of two 90 deg. analysing magnets with mass energy product 120 MeV amu and a gas-filled ionization chamber. The system will be complete with a Wien filter and a multi-anode gas detector with time-of-flight discrimination. Presently, the AMS facility is undergoing tests and routine measurements are expected to start soon

  12. AMS at the National Institute of Nuclear Physics and Engineering in Bucharest

    Energy Technology Data Exchange (ETDEWEB)

    Stan-Sion, C. E-mail: stansion@ifin.nipne.ro; Ivascu, M.; Plostinaru, D.; Catana, D.; Marinescu, L.; Radulescu, M.; Nolte, E

    2000-10-01

    A new beam line and injector deck for AMS measurements have been built at the 8 MV tandem accelerator of the National Institute of Nuclear Physics and Engineering, Bucharest, Romania. The main components on the low-energy side are a high-current cesium sputter source, a 90 deg. injection magnet and a pre-acceleration stage. At the high-energy side the beam line is achromatic, consisting of two 90 deg. analysing magnets with mass energy product 120 MeV amu and a gas-filled ionization chamber. The system will be complete with a Wien filter and a multi-anode gas detector with time-of-flight discrimination. Presently, the AMS facility is undergoing tests and routine measurements are expected to start soon.

  13. Physical activity and depression symptoms among pregnant women from the National Health and Nutrition Examination Survey 2005-2006.

    Science.gov (United States)

    Loprinzi, Paul D; Fitzgerald, Elizabeth M; Cardinal, Bradley J

    2012-03-01

    To examine the association between objectively measured physical activity and depression symptoms among a nationally representative sample of pregnant women to provide a more accurate understanding of the relationship between physical activity and depression symptoms. We employed a cross-sectional study design. Data from the National Health and Nutrition Examination Survey 2005-2006 were used for this study. One-hundred and forty-one pregnant women wore an ActiGraph accelerometer for 7 days and completed the Patient Health Questionnaire-9 to assess depression status. More than 19% of the participants experienced some depression symptoms, and compared to their counterparts not having depression symptoms, they were less physically active. An inverse association was found between physical activity and depression symptoms among pregnant women. When feasible, nurses are encouraged to help facilitate physical activity among pregnant women, assuming an uncomplicated pregnancy. © 2012 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  14. Progress during ten years of National Laboratory for High Energy Physics

    International Nuclear Information System (INIS)

    1981-01-01

    Ten years have elapsed since the birth of the National Laboratory for High Energy Physics. For the growth to the present status, the researchers concerned, the Science Council of Japan, the Ministry of Education, the National Diet and many enterprises, all contributed greatly. The proton synchrotron was completed as scheduled, and its performance largely exceeded the initial target. The results of the common utilization experiments started in 1977 have been obtained successively, and the applied research other than the field of elementary particles also has advanced along the right line steadily, such as booster utilization facility and radiated beam experiment facility. In this year, the construction of the Tristan project has been started, and the pet name ''KEK'' is internationally well known now. The 21st century is said to be the age of elementary particles, and the mission and responsibility put on the researchers concerned will be heavier. In this book, the progress of the KEK during ten years is reviewed, and many persons who took part in the establishment of the KEK contributed their memoirs. Also, the round-table talk held on this occasion, the history of each research group, the future plans, the results of researches and the related materials are described. (Kako, I.)

  15. Dietary and Physical Activity Pattern in Fars Province, National Plan of Chronic

    Directory of Open Access Journals (Sweden)

    Mahin Farahmand

    2013-03-01

    Full Text Available Background: Changes in lifestyle, especially in different aspects of nutrition and physical activity, have been associated with change in the patterns of diseases, from contagious diseases to non-communicable diseases, and with the prevalence of chronic diseases. Accordingly, this study is carried out within the framework of National Plan to Care for Risk Factors of Non-communicable Diseases with the aim of comparing the dietary patterns and physical activity of people under study in Fars province during 2006-2007. Materials and Methods: Using the WHO Step-by-step Evaluation Model for Risky Factors, the present study determined fifty 20-person clusters, totally 1,000 people within the age group of 15-64 for each year as the research population. After identifying the applicable people, they were visited at their homes and the questionnaires were filled out for them. The necessary analysis was carried out using Version 6 of EPI-info and Version 10 of STATA software.Results: The findings of the present study indicated that men have more intense physical activity than women (p=0.001. The results also indicated a significant increase in consumption of fruit (p=0.01, vegetable (p=0.001, and fish (p=0.001 in 2007 as compared with 2006. The average number of the consumed vegetable units in women was higher than that of men (p=0.01.Conclusion: The findings of this study indicated that the average number of daily consumed units of fruit and vegetable as well as the frequencies of fish consumption per week was lower than the recommended amounts.

  16. Physical activity in young adults: a signal detection analysis of Health Information National Trends Survey (HINTS) 2007 data.

    Science.gov (United States)

    Valle, Carmina G; Tate, Deborah F; Mayer, Deborah K; Allicock, Marlyn; Cai, Jianwen; Campbell, Marci K

    2015-01-01

    Many young adults are insufficiently active to achieve the health benefits of regular physical activity. Using signal detection analysis of data from the 2007 Health Information National Trends Survey, the authors examined distinct subgroups of 18-39 year-old adults who vary in their likelihood of not meeting physical activity recommendations. We randomly split the sample and conducted signal detection analysis on the exploratory half to identify subgroups and interactions among sociodemographic and health communication variables that predicted engaging in less than 150 minutes per week of moderate-intensity physical activity (low physical activity). We compared rates of low physical activity among subgroups with similarly defined subgroups in the validation sample. Overall, 62% of participants did not meet physical activity recommendations. Among 8 subgroups identified, low physical activity rates ranged from 31% to 90%. Predictors of low physical activity were general health, body mass index (BMI), perceived cancer risk, health-related Internet use, and trust in information sources. The least active subgroup (90% low physical activity) included young adults in poor to good health with a BMI of 30.8 or more (obese). The most active subgroup (31% low physical activity) comprised those in very good to excellent health, who used a website to help with diet, weight, or physical activity, and had little to no trust in health information on television. Findings suggest potential intervention communication channels and can inform targeted physical activity interventions for young adults.

  17. Method of doping a semiconductor

    International Nuclear Information System (INIS)

    Yang, C.Y.; Rapp, R.A.

    1983-01-01

    A method is disclosed for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient

  18. Accelerator Mass Spectrometry at the National Institute of Nuclear Physics and Engineering in Bucharest

    International Nuclear Information System (INIS)

    Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.; Ivascu, M.; Marinescu, L.; Dima, R.

    2000-01-01

    The Accelerator Mass Spectrometry (AMS) is today the experimental physical method capable to measure the lowest concentration of a particular nuclide in a sample material. Ratios of radionuclides in the range 10 -13 - 10 -15 are normally measured with this technique, corresponding to a sensitivity which makes possible the detection of only 1 Atom in a surrounding material of about 1 Million of Billions of other Atoms. Thus, the AMS has advanced the art of Classical Mass Spectrometry (sensitivity 10 -11 ) to a sensitivity which allows for the first time the performance of special applications in environmental physics, medicine, pharmacology, geology, archaeology, measurements of radio nuclides in the Earth's atmosphere produced by cosmic-rays or by nuclear power plants, applications in astrophysics and in nuclear physics.An Accelerator Mass Spectrometry facility was constructed at the FN - 8 MV tandem accelerator of the National Institute of Physics and Nuclear Engineering . The construction was possible in the frame of a co-operation with the Technical University Munich and with financial support from IAEA-Vienna. It represents the first experimental set-up of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarized at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses) a double focussing, 90 angle analyzing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight-stack magazine attached to the ion source. On the exit side of the tandem accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high-energy side, is optically achromatic and contains two 90 angle analyzing magnets of

  19. Teen Dating Violence (Physical and Sexual) Among US High School Students: Findings From the 2013 National Youth Risk Behavior Survey.

    Science.gov (United States)

    Vagi, Kevin J; O'Malley Olsen, Emily; Basile, Kathleen C; Vivolo-Kantor, Alana M

    2015-05-01

    National estimates of teen dating violence (TDV) reveal high rates of victimization among high school populations. The Centers for Disease Control and Prevention's national Youth Risk Behavior Survey has provided often-cited estimates of physical TDV since 1999. In 2013, revisions were made to the physical TDV question to capture more serious forms of physical TDV and to screen out students who did not date. An additional question was added to assess sexual TDV. To describe the content of new physical and sexual TDV victimization questions first administered in the 2013 national Youth Risk Behavior Survey, to share data on the prevalence and frequency of TDV (including the first-ever published overall "both physical and sexual TDV" and "any TDV" national estimates using these new questions), and to assess associations of TDV experience with health-risk behaviors. Secondary data analysis of a cross-sectional survey of 9900 students who dated, from a nationally representative sample of US high school students, using the 2013 national Youth Risk Behavior Survey. Two survey questions separately assessed physical and sexual TDV; this analysis combined them to create a 4-level TDV measure and a 2-level TDV measure. The 4-level TDV measure includes "physical TDV only," "sexual TDV only," "both physical and sexual TDV," and "none." The 2-level TDV measure includes "any TDV" (either or both physical and sexual TDV) and "none." Sex-stratified bivariate and multivariable analyses assessed associations between TDV and health-risk behaviors. In 2013, among students who dated, 20.9% of female students (95% CI, 19.0%-23.0%) and 10.4% of male students (95% CI, 9.0%-11.7%) experienced some form of TDV during the 12 months before the survey. Female students had a higher prevalence than male students of physical TDV only, sexual TDV only, both physical and sexual TDV, and any TDV. All health-risk behaviors were most prevalent among students who experienced both forms of TDV and were

  20. Time trends in leisure time physical activity and physical fitness in elderly people: 20 year follow-up of the Spanish population national health survey (1987-2006

    Directory of Open Access Journals (Sweden)

    Carrasco-Garrido Pilar

    2011-10-01

    Full Text Available Abstract Background To estimate trends in leisure time physical activity and physical fitness between 1987-2006 in older Spanish people. Methods We analyzed data collected from the Spanish National Health Surveys conducted in 1987 (n = 29,647, 1993 (n = 20,707, 1995-1997 (n = 12,800, 2001 (n = 21,058, 2003 (n = 21,650, and 2006 (n = 29,478. The number of subjects aged ≥ 65 years included in the current study was 29,263 (1987: n = 4,958-16.7%; 1993: n = 3,751-17.8%; 1995-97: n = 2,229-17.4%; 2001: n = 4,356-20.7%; 2003: 6,134-28.3%; 2006: 7,835-26.5%. Main variables included leisure-time physical activity and physical fitness. We analyzed socio-demographic characteristics, self-rated health status, lifestyle habit and co-morbid conditions using multivariate logistic regression models. Results Women exhibited lower prevalence of leisure time physical activity and physical fitness compared to men (P Conclusions We found an increase in leisure time physical activity in the older Spanish population. Older age, married status, co-morbid conditions, obesity, and worse self-perceived health status were associated with lower activity. Identification of these factors can help to identify individuals at risk for physical inactivity.

  1. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    enhanced in quantum confined lower-dimensional systems, where exciton and biexciton effects dominate the spectra even at room temperature. The coherent dynamics of excitons are at modest densities well described by the optical Bloch equations and a number of the dynamical effects known from atomic......Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  2. Hydrogen in semiconductors II

    CERN Document Server

    Nickel, Norbert H; Weber, Eicke R; Nickel, Norbert H

    1999-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition ...

  3. Physical activity and sedentary behavior of cancer survivors and non-cancer individuals: results from a national survey.

    Science.gov (United States)

    Kim, Roy B; Phillips, Allison; Herrick, Kirsten; Helou, Marieka; Rafie, Carlin; Anscher, Mitchell S; Mikkelsen, Ross B; Ning, Yi

    2013-01-01

    Increasing physical activity and decreasing sedentary behavior are associated with a higher quality of life and lower mortality rates for cancer survivors, a growing population group. Studies detailing the behavior of cancer survivors are limited. Therefore, we investigated physical activity and sedentary behavior of cancer survivors using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Participants were those who provided physical activity and sedentary behavior data. Those who were pregnant, physical activity, compared to non-cancer participants. These patterns are similar for breast and prostate cancer survivors, with prostate cancer survivors more likely to engage in physical activity for more than one hour per day (OR = 1.98, 95% CI (1.05, 3.71)). Our findings suggest that cancer survivors tend to have more physical activity, but they are also more likely to engage in sedentary behavior.

  4. Low Dimensional Semiconductor Structures Characterization, Modeling and Applications

    CERN Document Server

    Horing, Norman

    2013-01-01

    Starting with the first transistor in 1949, the world has experienced a technological revolution which has permeated most aspects of modern life, particularly over the last generation. Yet another such revolution looms up before us with the newly developed capability to control matter on the nanometer scale. A truly extraordinary research effort, by scientists, engineers, technologists of all disciplines, in nations large and small throughout the world, is directed and vigorously pressed to develop a full understanding of the properties of matter at the nanoscale and its possible applications, to bring to fruition the promise of nanostructures to introduce a new generation of electronic and optical devices. The physics of low dimensional semiconductor structures, including heterostructures, superlattices, quantum wells, wires and dots is reviewed and their modeling is discussed in detail. The truly exceptional material, Graphene, is reviewed; its functionalization and Van der Waals interactions are included h...

  5. Semiconductor detectors with proximity signal readout

    International Nuclear Information System (INIS)

    Asztalos, Stephen J.

    2012-01-01

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need

  6. Leisure-time Physical Activity Among Different Social Groups of Estonia: Results of the National Physical Activity Survey

    Directory of Open Access Journals (Sweden)

    Lusmägi Peeter

    2016-03-01

    Full Text Available According to the Eurobarometer (European Commission, 2010, 39% of the Estonian adult population is not physically active at all. This percentage is relatively high compared to other countries that are culturally close to Estonia; the corresponding figure of close neighbors Finland and Sweden is below 10%. The article aims to present the results of a survey of physical activity (n=1,009 conducted in Estonia in 2013 and analyzes physical activity levels across various social groups. The results of the article show that employment, age, education, and ethnicity are important factors for engaging in leisure-time physical activity in Estonia. Non-ethnic Estonians, the less educated, the elderly, the unemployed, and those on maternity leave are less engaged in regular leisure exercise than people in other social groups. The results of the article were used to develop Estonia’s Sports 2030 strategy.

  7. Advances in semiconductor lasers

    CERN Document Server

    Coleman, James J; Jagadish, Chennupati

    2012-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scien

  8. Superconductivity in doped semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bustarret, E., E-mail: Etienne.bustarret@neel.cnrs.fr

    2015-07-15

    A historical survey of the main normal and superconducting state properties of several semiconductors doped into superconductivity is proposed. This class of materials includes selenides, tellurides, oxides and column-IV semiconductors. Most of the experimental data point to a weak coupling pairing mechanism, probably phonon-mediated in the case of diamond, but probably not in the case of strontium titanate, these being the most intensively studied materials over the last decade. Despite promising theoretical predictions based on a conventional mechanism, the occurrence of critical temperatures significantly higher than 10 K has not been yet verified. However, the class provides an enticing playground for testing theories and devices alike.

  9. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  10. Age, sex, and racial differences in harsh physical punishment: results from a nationally representative United States sample.

    Science.gov (United States)

    Taillieu, Tamara L; Afifi, Tracie O; Mota, Natalie; Keyes, Katherine M; Sareen, Jitender

    2014-12-01

    The purpose of this research was to examine age, sex, and racial differences in the prevalence of harsh physical punishment in childhood in a nationally representative sample of the United States. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) collected in 2004 and 2005 (n=34,653). Logistic regression analyses were conducted to examine age, sex, and racial differences in the prevalence of harsh physical punishment. Results suggest that the prevalence of harsh physical punishment has been decreasing among more recently born age groups; however, there appear to be sex and racial differences in this trend over time. The magnitude of the decrease appears to be stronger for males than for females. By race, the decrease in harsh physical punishment over time is only apparent among Whites; Black participants demonstrate little change over time, and harsh physical punishment seems to be increasing over time among Hispanics. Prevention and intervention efforts that educate about the links of physical punishment to negative outcomes and alternative non-physical discipline strategies may be particularly useful in reducing the prevalence of harsh physical punishment over time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Dopants and defects in semiconductors

    CERN Document Server

    McCluskey, Matthew D

    2012-01-01

    "The book goes beyond the usual textbook in that it provides more specific examples of real-world defect physics … The book will be most useful for beginning graduate students in materials science. … an easy reading, broad introductory overview of the field …"-Materials Today, July-August 2012"… well written, with clear, lucid explanations …"-Chemistry World"The scientific development towards the method of controllable doping transformed the erratic and not reproducible family of semiconductor materials into the truly wonderful basis of modern microelectronics. This book tells the remarkable success story and I recommend it!"-Hans J. Queisser, Max-Planck-Institute, Stuttgart, Germany"McCluskey and Haller have written an outstanding modern guide to this field that will be useful to newcomers, and also to active researchers who want to broaden their horizons, as a means to learn the capabilities and limitations of the many techniques that are used in semiconductor-defect science."-Professor Michael J....

  12. The ATLAS semiconductor tracker (SCT)

    International Nuclear Information System (INIS)

    Jackson, J.N.

    2005-01-01

    The ATLAS detector (CERN,LHCC,94-43 (1994)) is designed to study a wide range of physics at the CERN Large Hadron Collider (LHC) at luminosities up to 10 34 cm -2 s -1 with a bunch-crossing rate of 40 MHz. The Semiconductor Tracker (SCT) forms a key component of the Inner Detector (vol. 1, ATLAS TDR 4, CERN,LHCC 97-16 (1997); vol. 2, ATLAS TDR 5, CERN,LHCC 97-17 (1997)) which is situated inside a 2 T solenoid field. The ATLAS Semiconductor Tracker (SCT) utilises 4088 silicon modules with binary readout mounted on carbon fibre composite structures arranged in the forms of barrels in the central region and discs in the forward region. The construction of the SCT is now well advanced. The design of the SCT modules, services and support structures will be briefly outlined. A description of the various stages in the construction process will be presented with examples of the performance achieved and the main difficulties encountered. Finally, the current status of the construction is reviewed

  13. Tunable radiation emitting semiconductor device

    NARCIS (Netherlands)

    2009-01-01

    A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

  14. Association Between Objectively Measured Physical Activity and Erectile Dysfunction among a Nationally Representative Sample of American Men.

    Science.gov (United States)

    Loprinzi, Paul D; Edwards, Meghan

    2015-09-01

    Emerging work suggests an inverse association between physical activity and erectile dysfunction (ED). The majority of this cross-sectional research comes from convenience samples and all studies on this topic have employed self-report physical activity methodology. Therefore, the purpose of this brief-report, confirmatory research study was to examine the association between objectively measured physical activity and ED in a national sample of Americans. Data from the 2003-2004 National Health and Nutrition Examination Survey were used. Six hundred ninety-two adults between the ages of 50 and 85 years (representing 33.2 million adults) constituted the analytic sample. Participants wore an ActiGraph 7164 accelerometer (ActiGraph, Pensacola, FL, USA) for up to 7 days with ED assessed via self-report. The main outcome measure used was ED assessed via self-report. After adjustments, for every 30 min/day increase in moderate-to-vigorous physical activity, participants had a 43% reduced odds of having ED (odds ratioadjusted  = 0.57; 95% confidence interval: 0.40-0.81; P = 0.004). This confirmatory study employing an objective measure of physical activity in a national sample suggests an inverse association between physical activity and ED. © 2015 International Society for Sexual Medicine.

  15. Physical Activity Level of Korean Adults with Chronic Diseases: The Korean National Health and Nutritional Examination Survey, 2010-2012.

    Science.gov (United States)

    Jin, Ho-Seong; An, Ah-Reum; Choi, Ho-Chun; Lee, Sang-Hyun; Shin, Dong-Heon; Oh, Seung-Min; Seo, Young-Gyun; Cho, Be-Long

    2015-11-01

    Proper physical activities are known to be helpful in the prevention and management of chronic diseases. However, the physical activity level of patients with chronic diseases is low. Therefore, this study aimed to investigate the physical activity compliance of patients with hypertension, diabetes, and dyslipidemia in Korea. This study analyzed the 2010-2012 Fifth Korean National Health and Nutrition Examination Survey data. We included 13,873 individuals in the analysis. The level of physical activity compliance was measured by performing multivariate logistic regression analyses. In the univariate analysis, the subjects with hypertension or diabetes tended to comply with the physical activity guidelines less faithfully than their healthy counterparts. The proportion of subjects with hypertension who were insufficiently physically active was 65.4% among the men and 75.8% among the women. For diabetes, the proportions were 66.7% and 76.8%, respectively. No significant difference was found between the subjects with dyslipidemia and their healthy counterparts. In the multivariate logistic regression analysis, no significant difference in physical activity compliance was observed between the subjects with hypertension, diabetes, or dyslipidemia and their healthy counterparts for both sexes. The patients with hypertension or diabetes tended to have lower physical activity prevlaence than their healthy counterparts. However, for dyslipidemia, no significant difference was found between the two groups. Given the significance of physical activities in the management of chronic diseases, the physical activities of these patients need to be improved.

  16. Handbook of luminescent semiconductor materials

    CERN Document Server

    Bergman, Leah

    2011-01-01

    Photoluminescence spectroscopy is an important approach for examining the optical interactions in semiconductors and optical devices with the goal of gaining insight into material properties. With contributions from researchers at the forefront of this field, Handbook of Luminescent Semiconductor Materials explores the use of this technique to study semiconductor materials in a variety of applications, including solid-state lighting, solar energy conversion, optical devices, and biological imaging. After introducing basic semiconductor theory and photoluminescence principles, the book focuses

  17. Depletion field focusing in semiconductors

    NARCIS (Netherlands)

    Prins, M.W.J.; Gelder, Van A.P.

    1996-01-01

    We calculate the three-dimensional depletion field profile in a semiconductor, for a planar semiconductor material with a spatially varying potential upon the surface, and for a tip-shaped semiconductor with a constant surface potential. The nonuniform electric field gives rise to focusing or

  18. Nonlinear Elasticity of Doped Semiconductors

    Science.gov (United States)

    2017-02-01

    AFRL-RY-WP-TR-2016-0206 NONLINEAR ELASTICITY OF DOPED SEMICONDUCTORS Mark Dykman and Kirill Moskovtsev Michigan State University...2016 4. TITLE AND SUBTITLE NONLINEAR ELASTICITY OF DOPED SEMICONDUCTORS 5a. CONTRACT NUMBER FA8650-16-1-7600 5b. GRANT NUMBER 5c. PROGRAM...vibration amplitude. 15. SUBJECT TERMS semiconductors , microresonators, microelectromechanical 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  19. Semi-conductor rectifiers

    International Nuclear Information System (INIS)

    1981-01-01

    A method is described for treating a semiconductor rectifier, comprising: heating the rectifier to a temperature in the range of 100 0 C to 500 0 C, irradiating the rectifier while maintaining its temperature within the said range, and then annealing the rectifier at a temperature of between 280 0 C and 350 0 C for between two and ten hours. (author)

  20. Physics of societal issues calculations on national security, environment, and energy

    CERN Document Server

    Hafemeister, David

    2014-01-01

    This book provides the reader with essential tools needed to analyze complex societal issues and demonstrates the transition from physics to modern-day laws and treaties. This second edition features new equation-oriented material and extensive data sets drawing upon current information from experts in their fields. Problems to challenge the reader and extend discussion are presented on three timely issues:   •        National Security: Weapons, Offense, Defense, Verification, Nuclear Proliferation, Terrorism •        Environment: Air/Water, Nuclear, Climate Change, EM Fields/Epidemiology •        Energy: Current Energy Situation, Buildings, Solar Buildings, Renewable  Energy, Enhanced End-Use Efficiency, Transportation, Economics   Praise for the first edition: "This insight is needed in Congress and the Executive Branch. Hafemeister, a former Congressional fellow with wide Washington experience, has written a book for physicists, chemists and engineers who want to learn science...

  1. Physics design requirements for the National Spherical Torus Experiment liquid lithium divertor

    International Nuclear Information System (INIS)

    Kugel, H.; Bell, M.; Berzak, L.; Brooks, A.; Ellis, R.; Gerhardt, S.P.; Kaita, R.; Kallman, J.; Majeski, R.; Mansfield, D.K.; Menard, J.; Stotler, D.; Zakharov, L.E.; Maingi, Rajesh; Nygren, R.E.; Soukhanovskii, V.; Wakeland, P.

    2009-01-01

    Recent National Spherical Tokamak Experiment (NSTX) high-power divertor experiments have shown significant and recurring benefits of solid lithium coatings on plasma facing components (PFCs) to the performance of divertor plasmas in both L- and H-mode confinement regimes heated by high-power neutral beams. The next step in this work is installation of a liquid lithium divertor (LLD) to achieve density control for inductionless current drive capability (e.g., about a 15 25% ne decrease from present highest non-inductionless fraction discharges which often evolve toward the density limit, ne/nGW 1), to enable ne scan capability (2) in the H-mode, to test the ability to operate at significantly lower density (e.g., ne/nGW = 0.25), for future reactor designs based on the Spherical Tokamak, and eventually to investigate high heat-flux power handling (10 MW/m2) with long pulse discharges (>1.5 s). The first step (LLD-1) physics design encompasses the desired plasma requirements, the experimental capabilities and conditions, power handling, radial location, pumping capability, operating temperature, lithium filling, MHD forces, and diagnostics for control and characterization.

  2. Computerization aspects of the Health Physics' Radiation Control Program at Argonne National Laboratory

    International Nuclear Information System (INIS)

    Dolecek, Elwyn H.

    1978-01-01

    Greater public awareness of the potential hazards of ionizing radiation and the more stringent governmental compliance programs have made accountability of radioactive materials an item of increasingly major concern for all radionuclide users. For low-volume (radioisotopically) organizations, manual record keeping techniques may suffice without requiring significant work-hour allocations. When considering high-volume users, the workload contingent with manual inventory is usually excessive from an employee time-allocation standpoint. Therefore, various automation systems are employed, usually with the aid of an in-house or time-purchase computer system. The computer programs developed for these systems often do not allow for future modification without major rewriting. Therefore, to facilitate in program concept, modification, and implementation the Health Physics Section at Argonne National Laboratory chose to design and code its computer program(s) and has instituted a Radiation Administrative Program (RAP) as a major component of the Section's laboratory-wide radiation control program. Coded in ANSI PL/I, RAP provides both flexibility in present concept and allowance for future growth. It requires less than 300K words of computer memory and can be easily incorporated at other organizations with minimal modifications. The modular design provides run cost benefits and versatility of report generation and modification. Through the use of this type of information processing and retrieval system, one can manipulate large amounts of radionuclide data, providing control and identification, while still maintaining commitment of computer costs and employee time at a reasonable level. (author)

  3. Forensic Science Research and Development at the National Institute of Justice: Opportunities in Applied Physics

    Science.gov (United States)

    Dutton, Gregory

    Forensic science is a collection of applied disciplines that draws from all branches of science. A key question in forensic analysis is: to what degree do a piece of evidence and a known reference sample share characteristics? Quantification of similarity, estimation of uncertainty, and determination of relevant population statistics are of current concern. A 2016 PCAST report questioned the foundational validity and the validity in practice of several forensic disciplines, including latent fingerprints, firearms comparisons and DNA mixture interpretation. One recommendation was the advancement of objective, automated comparison methods based on image analysis and machine learning. These concerns parallel the National Institute of Justice's ongoing R&D investments in applied chemistry, biology and physics. NIJ maintains a funding program spanning fundamental research with potential for forensic application to the validation of novel instruments and methods. Since 2009, NIJ has funded over 179M in external research to support the advancement of accuracy, validity and efficiency in the forensic sciences. An overview of NIJ's programs will be presented, with examples of relevant projects from fluid dynamics, 3D imaging, acoustics, and materials science.

  4. Physical properties of a linear accelerator-based stereotactic installed at national cancer institute

    International Nuclear Information System (INIS)

    Attala, E.M.; Deiab, N.A.; Elawady, R.A.

    2005-01-01

    The purpose of this paper is to present the dosimetry and mechanical accuracy of the first dedicated Siemens PRIMUS M6/6ST linear accelerator-based Stereotactic installed in National Cancer Institute for stereotactic radiosurgery and radiotherapy (SRS/SRT). The data were obtained during the installation, acceptance test procedure, and commissioning of the unit. The Primus M6/6ST has a single 6-MV beam with the same beam characteristics as that of the mother unit, the Siemens. The dosimetric data were taken using pin point ion chamber. The cone sizes vary from 12.5 to 40.0 mm diameter. The mechanical stability of the entire system was verified. The variations in isocenter position with table, gantry, and collimator rotation were found to be < 0.5 mm with a compounded accuracy of < or = 1.0 mm. The beam profiles of all cones in the x and y directions were within +/- 0.5 mm and match with the physical size of the cone. The basic dosimetry parameters such as tissue maximum ratio (TMR), off-axis ratio (OAR) and cone factor needed for patient treatment were evaluated. The mechanical and dosimetric characteristics including dose linearity of this unit are presented and found to be suitable for SRS/SRT. The difficulty in absolute dose measurement for small cone is discussed

  5. Evaluation of the Undergraduate Physics Programme at Indira Gandhi National Open University: A Case Study

    Directory of Open Access Journals (Sweden)

    Arundhati Mishra

    2009-12-01

    Full Text Available The undergraduate science programme was launched at the Indira Gandhi National Open University (IGNOU in 1991-92 with an enrolment of 1,210 students. The programme was well received, and enrolments increased over the years. However, the success rates have not kept pace with enrolment.In this paper, the authors report the results of an evaluation of the undergraduate Physics programme at IGNOU. The evaluation, the first of its type for this programme, adapted the major tenets of the CIPP model. The findings are based on the responses from a randomly chosen sample of 509 learners across India. The methods employed for the study include records, document, and database analysis, surveys, and case studies.Although the University has enhanced access to higher science education, the attrition rate is high (73%, and the success rate is low. The authors recommend that the University review and reorient its strategies for providing good quality, learner-centred higher education in science subjects. The programme should address the concerns of the learners about the effectiveness of the student support systems, the difficulty level, and the learner-friendliness of study materials with the goal of achieving long-term sustainability while maintaining parity with the conventional system. The need for improving the presentation of the courses and simplifying the mathematical details is emphasised.

  6. Development of the negative ion source at the National Laboratory for High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Akira [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-02-01

    On formation of direct high frequency chopped negative hydrogen ion beam from surface forming type negative hydrogen ion source, incident acceleration due to proton synchrotron was tried for a forming experiment and its application. By overlapping a high frequency pulse onto a bias DC voltage of convertor electrode, control of formation of negative hydrogen ion with high speed RF pulse of 2 MHz could be realized. And, incidence into 12 GeV proton accelerator to catch RF particles with waiting bucket system due to booster synchrotron, was effective for control of longitudinal emittance in the booster synchrotron. As a result, controls of the beam width and shape emitted from the booster synchrotron were possible. On application of high speed chopped negative hydrogen ion beam to accelerator, improvement of beam capture efficiency to the accelerated RF bucket, control of longitudinal emittance of accelerated beam, beam measurement at incidence into the accelerator and so forth were conducted. In this paper, results of the high speed chopped beam formation experiment using surface plasma forming type negative ion source and application of high speed beam chopping method synchronized with high frequency pulse at the National Laboratory of High Energy Physics are described. (G.K.)

  7. Physical Activity Attenuates Total and Cardiovascular Mortality Associated With Physical Disability: A National Cohort of Older Adults.

    Science.gov (United States)

    Martinez-Gomez, David; Guallar-Castillon, Pilar; Higueras-Fresnillo, Sara; Garcia-Esquinas, Esther; Lopez-Garcia, Esther; Bandinelli, Stefania; Rodríguez-Artalejo, Fernando

    2018-01-16

    Regular physical activity (PA) has been shown to protect against disability onset but, once the disability is present, it is unclear if PA might attenuate its harmful health consequences. Thus, we examined if mortality risk associated with physical disability can be offset by PA among older adults. We used data from a cohort of 3,752 individuals representative of the noninstitutionalized population aged 60 years and older in Spain. In 2000-2001, participants self-reported both PA levels (inactive, occasionally, monthly, weekly) and five physical disabilities (agility, mobility, global daily activities, instrumental activities of daily living, and self-care). Individuals were prospectively followed through 2014 to assess incident deaths. The mean follow-up was 10.8 years, with a total of 1,727 deaths, 638 of them due to cardiovascular disease (CVD). All disability types were associated with higher total and CVD mortality. Being physically active (ie, doing any PA) was associated with a statistically significant 26%-37% and 35%-50% lower risk of total and CVD death, respectively, across types of disability. As compared with those being physically active and without disability, those who were inactive and had a disability showed the highest mortality risk from total (hazard ratios from 1.52 to 1.90 across disabilities, all p disability. In older adults, PA could attenuate the increased risk of mortality associated with physical disability. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. National Institute of Research and Development for Earth Physics, Bucharest: 25 Years of activity

    International Nuclear Information System (INIS)

    Marmureanu, Gh.

    2002-01-01

    The experimental research in Earth Physics has a tradition of over one century in Romania, the first seismological station and the first magnetic map of the country (1892) being the work of Stefan Hepites, member of the Romanian Academy. Hepites made the first systematic macroseismic observations as earlier as 1892. These results were obtained within the meteorological network that in 1901 was operating 400 stations all over the country. The first seismic instruments were installed in Romania at Bucharest in 1895 and were a microseismoscop Guzzanti and a Tacchini pendulum. In 1904 the Kingdom of Romania adhered at International Association of Seismology and Stefan Hepites was appointed in the Permanent Commission of Seismology. The beginning of the 20th century marked the setting up of Timisoara station in 1904. The station of substantially improved in 1943 by prof. Ion Curea who installed two horizontal mechanical pendulums of 540 Kg. After an interruption between 1944 and 1950 this station has been operated continuously until the present time. The Romanian seismological service was founded in January 1, 1935 under the leader ship of prof. G. Demetrescu in the framework of the Seismic Observatory of Bucharest. The seismic network consisting of 2 stations (at Bucharest and Cernauti) in 1936, was extended to 5 more stations after the occurrence of the strong earthquake of 1940 (45.8 angle N, 26.7 angle E, h =150 Km, M w = 7.7) at Focsani, Bacau, Campu Lung, Iasi and Vrancioaia. In his study, Demetrescu evidenced the present of a persistent and isolated seismic focus characterized by deep earthquake localized beneath the Carpathians are bend, in the Vrancea region. The second stronger earthquake in modern time was that of 1977. A radio-telemetric array of 15 seismic stations was installed with PNUD - UNESCO support. In 1977 the National Institute for Earth Physics (NIEP) was founded. Its main tasks are: 1. Monitoring of seismicity (Operation and maintenance of the

  9. Relative validity of the pre-coded food diary used in the Danish National Survey of Diet and Physical Activity

    DEFF Research Database (Denmark)

    Knudsen, Vibeke Kildegaard; Gille, Maj-Britt; Nielsen, Trine Holmgaard

    2011-01-01

    Objective: To determine the relative validity of the pre-coded food diary applied in the Danish National Survey of Dietary Habits and Physical Activity. Design: A cross-over study among seventy-two adults (aged 20 to 69 years) recording diet by means of a pre-coded food diary over 4 d and a 4 d...

  10. Slow and fast light effects in semiconductor waveguides for applications in microwave photonics

    DEFF Research Database (Denmark)

    Mørk, Jesper; Öhman, Filip; Xue, Weiqi

    2008-01-01

    We review the physics of slow and fast light effects in semiconductor waveguides. Different schemes for achieving optically or electronically controlled phase shifts are introduced and explained.......We review the physics of slow and fast light effects in semiconductor waveguides. Different schemes for achieving optically or electronically controlled phase shifts are introduced and explained....

  11. Is spending time in screen-based sedentary behaviors associated with less physical activity: a cross national investigation

    Directory of Open Access Journals (Sweden)

    Iannotti Ronald J

    2010-05-01

    Full Text Available Abstract Background In Australia and the USA, national guidelines exist for limiting children's screen-exposure to two hours per day. This study aims to determine whether exceeding the suggested guidelines for screen-based sedentary behavior is associated with reduced levels of physical activity across different geographical regions. Methods Data material were taken from the 2005/2006 survey of "Health Behaviour in School-aged Children (HBSC study; A WHO cross-National Survey". Data were collected through questionnaires from 11-,13- and,15- year olds. The final sample included 200,615 adolescents from 39 different countries in Europe and North America. Gender and country stratified analyses regressed time spent in leisure-time vigorous physical activity (VPA and days of 60 minutes moderate to vigorous physical activity (MVPA on time spent in screen-based sedentary behaviors. To simplify interpretation, the estimates from each country were pooled using a meta-analytic procedure. Results Exceeding 2 hrs of daily total screen-time was negatively associated with MVPA for both boys and girls, and with VPA for girls. When investigating the different types of screen-based behaviors separately, exceeding 2 hrs daily of TV viewing was associated with less MVPA for both boys and girls and less VPA for girls. Gaming was associated with less MVPA and VPA for boys, and non-gaming computer use was associated with higher levels of VPA for both genders. Stronger negative associations between physical activity and screen-based sedentary behaviors were found in countries where mean levels of physical activity were relatively high. The association between physical activity and sedentary behavior was not significantly associated with national levels of screen-based sedentary behaviors. Conclusions The displacement mechanism does not appear to be universal across countries. On a national level, negative associations between physical activity and screen

  12. Bandgap Optimization of Perovskite Semiconductors for Photovoltaic Applications.

    Science.gov (United States)

    Xiao, Zewen; Zhou, Yuanyuan; Hosono, Hideo; Kamiya, Toshio; Padture, Nitin P

    2018-02-16

    The bandgap is the most important physical property that determines the potential of semiconductors for photovoltaic (PV) applications. This Minireview discusses the parameters affecting the bandgap of perovskite semiconductors that are being widely studied for PV applications, and the recent progress in the optimization of the bandgaps of these materials. Perspectives are also provided for guiding future research in this area. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Defect Characterization in Semiconductors with Positron Annihilation Spectroscopy

    Science.gov (United States)

    Tuomisto, Filip

    Positron annihilation spectroscopy is an experimental technique that allows the selective detection of vacancy defects in semiconductors, providing a means to both identify and quantify them. This chapter gives an introduction to the principles of the positron annihilation techniques and then discusses the physics of some interesting observations on vacancy defects related to growth and doping of semiconductors. Illustrative examples are selected from studies performed in silicon, III-nitrides, and ZnO.

  14. Metastable states in amorphous chalcogenide semiconductors

    CERN Document Server

    Mikla, Victor I

    2009-01-01

    This book addresses an interesting and technologically important class of materials, the amorphous chalcogenide semiconductors. Experimental results on the structural and electronic metastable states in Se-rich chalcogenides are presented. Special attention is paid to the states in the mobility gap and their sensitivity to various factors such as irradiation, annealing and composition. Photoinduced changes of structure and physical properties are also considered and structural transformation at photocrystallization is studied in detail. Finally, the authors discuss potential applications of th

  15. Wave mechanics applied to semiconductor heterostructures

    International Nuclear Information System (INIS)

    Bastard, G.

    1990-01-01

    This book examines the basic electronic and optical properties of two dimensional semiconductor heterostructures based on III-V and II-VI compounds. The book explores various consequences of one-dimensional size-quantization on the most basic physical properties of heterolayers. Beginning with basic quantum mechanical properties of idealized quantum wells and superlattices, the book discusses the occurrence of bound states when the heterostructure is imperfect or when it is shone with near bandgap light

  16. Semiconductor Laser Tracking Frequency Distance Gauge

    Science.gov (United States)

    Phillips, James D.; Reasenberg, Robert D.

    2009-01-01

    Advanced astronomical missions with greatly enhanced resolution and physics missions of unprecedented accuracy will require a spaceworthy laser distance gauge of substantially improved performance. The Tracking Frequency Gauge (TFG) uses a single beam, locking a laser to the measurement interferometer. We have demonstrated this technique with pm (10(exp -12) m) performance. We report on the version we are now developing based on space-qualifiable, fiber-coupled distributed-feedback semiconductor lasers.

  17. Anomalous hall effect in ferromagnetic semiconductors

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Tomáš; Niu, Q.; MacDonald, A. H.

    2002-01-01

    Roč. 88, č. 20 (2002), s. 207208-1-207208-4 ISSN 0031-9007 R&D Projects: GA ČR GA202/02/0912; GA MŠk OC P5.10 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * anomalous Hall effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.323, year: 2002

  18. Physical and physiological differences of backs and forwards from the Brazilian National rugby union team.

    Science.gov (United States)

    Nakamura, Fábio Y; Pereira, Lucas A; Moraes, José E; Kobal, Ronaldo; Kitamura, Katia; Cal Abad, Cesar C; Teixeira Vaz, Luís M; Loturco, Irineu

    2017-12-01

    The aim of this study was to compare backs and forwards rugby union players recruited to a National team in the following physical and physiological indicators: anthropometrics, squat jump (SJ), countermovement jump (CMJ), 10- and 30-meter sprint, resting heart rate variability (HRV), Yo-Yo Test and heart rate (HR) at 2 minutes of test. The measurements were performed on the first day of a training camp planned to finely select the players who would participate in the 2016 America's Rugby Championship. The magnitude-based inference was used in the comparisons. Backs demonstrated almost certainly greater distance in the Yo-Yo Test (backs: 2305.9±231.3 meters; forwards: 1802.4±361.2 meters), higher vertical jump height in both SJ and CMJ (SJ: 44.0±5.3 cm vs. 37.6±5.4 cm; CMJ: 46.1±5.0 cm vs. 40.0±5.5 cm, for backs and forwards respectively), and superior sprint velocity in 10- and 30-m (10-m: 6.02±0.23 m.s-1 vs. 5.51±0.34 m.s-1; 30-m: 7.46±0.25 m.s-1 vs. 6.89±0.37 m.s-1, for backs and forwards respectively) than the forwards. In contrast, forwards were almost certainly taller and heavier than backs, and displayed higher sprint momentum in 10- and 30-meters (10 meters: 513.0±51.6 kg.m.s-1 vs. 598.4±53.1 kg.m.s-1; 30 meters: 635.3±56.1 kg.m.s-1 vs. 749.0±70.5 kg.m.s-1, for backs and forwards respectively). The submaximal HR in the first 2-minutes of the Yo-Yo test was likely lower in the backs than in the forwards (77.6±5.1% of the maximal HR vs. 81.3±5.4% of the maximal HR for backs and forwards respectively), while HRV indices were not different between backs and forwards. Playing position appears to be determined by the players' physical and physiological characteristics in top-level rugby union, and the submaximal HR measured during Yo-Yo test can be a simple alternative to discriminate backs and forwards.

  19. SU-E-P-19: A National Collaborative Academic Medical Physics Network: Structure, Activity and Outcomes

    International Nuclear Information System (INIS)

    Thwaites, D

    2015-01-01

    Purpose: A national Australian inter-university medical physics (MP) group was formed in 2011/12, supported by Department of Health Better Access to Radiation Oncology BARO) seed funding. Core membership includes the six universities providing postgraduate MP courses. Objectives include increasing capacity, development and efficiency of national academic MP structures/systems and hence supporting education, clinical training and research, for the MP workforce support. Although the BARO scheme focuses on Radiation Oncology, the group has wider MP interests. Methods: Two further BARO seed grants were achieved: 1) for networked academic activities, including shared-resource teaching, eg using virtual reality systems; MP outreach to schools and undergraduates; developing web-based student and registrar education/resources, etc.; and 2) for conjoint ‘translational research’ posts between universities and partner hospitals, to clinically progress advanced RT technologies and to support students and registrars. Each university received 0.5 FTE post from each grant over 2 years (total: $1.75M) and leveraged local additional partner funds. Results: Total funding: $4–5M. Overall there have been 35 (mainly overseas) postholders bringing specific expertise, beginning in early 2013. Periods in Australia have been from 0.25–2 years (median=1). As well as the education activities, research projects include lung/spine SBRT, 4D RT, FFF beams, technology assessment, complex treatment planning, imaging for radiation oncology, DIR, adaptive breast, datamining, radiomics,etc. Observed positive impacts include: increased interest in MP courses, training support, translational research infrastructure and/or clinical practice in the hospitals involved, plus increased collaboration and effectiveness between the universities. Posts are continuing beyond grant end using leveraged funds, providing the basis for sustainability of some posts. Conclusion: The BARO-funded projects have

  20. SU-E-P-19: A National Collaborative Academic Medical Physics Network: Structure, Activity and Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Thwaites, D [University of Sydney, Camperdown, Sydney (Australia)

    2015-06-15

    Purpose: A national Australian inter-university medical physics (MP) group was formed in 2011/12, supported by Department of Health Better Access to Radiation Oncology BARO) seed funding. Core membership includes the six universities providing postgraduate MP courses. Objectives include increasing capacity, development and efficiency of national academic MP structures/systems and hence supporting education, clinical training and research, for the MP workforce support. Although the BARO scheme focuses on Radiation Oncology, the group has wider MP interests. Methods: Two further BARO seed grants were achieved: 1) for networked academic activities, including shared-resource teaching, eg using virtual reality systems; MP outreach to schools and undergraduates; developing web-based student and registrar education/resources, etc.; and 2) for conjoint ‘translational research’ posts between universities and partner hospitals, to clinically progress advanced RT technologies and to support students and registrars. Each university received 0.5 FTE post from each grant over 2 years (total: $1.75M) and leveraged local additional partner funds. Results: Total funding: $4–5M. Overall there have been 35 (mainly overseas) postholders bringing specific expertise, beginning in early 2013. Periods in Australia have been from 0.25–2 years (median=1). As well as the education activities, research projects include lung/spine SBRT, 4D RT, FFF beams, technology assessment, complex treatment planning, imaging for radiation oncology, DIR, adaptive breast, datamining, radiomics,etc. Observed positive impacts include: increased interest in MP courses, training support, translational research infrastructure and/or clinical practice in the hospitals involved, plus increased collaboration and effectiveness between the universities. Posts are continuing beyond grant end using leveraged funds, providing the basis for sustainability of some posts. Conclusion: The BARO-funded projects have

  1. Thermodynamic concepts in semiconductor quantum dot technology

    International Nuclear Information System (INIS)

    Shchukin, V.

    2001-01-01

    Major trends of the modern civilization are related to the changing of the industrial society into an information and knowledge-based society. This transformation is to a large extent based on the modern information and communication technology. The nobel prize-2000 in physics is a remarkable recognition of an extremely high significance of this kind of technology. The nobel prize has been awarded with one half jointly to Zhores I. Alferov and Herbert Kroemer for developing semiconductor heterostructures used in high-speed- and opto-electronics and one half to Jack St. Clair Kilby for this part in the invention of the integrated circuit. The development of the semiconductor heterostructures technology requires a profound understanding of the basic growth mechanisms involved in any technological process, including any type of epitaxy, either the liquid phase epitaxy (LPE), or the metalorganic vapor phase epitaxy (MOVPE), or the molecular beam epitaxy (MBE). Starting from this pioneering works on semiconductor heterostructures till present time, Professor Zh. Alferov has always paid much attention to complex and comprehensive study of the subject. This covers the growth - as well as the post-growth technology including the theoretical modeling of the technology, the characterization of the heterostructures, and the device design. Such complex approach has master mined the scientific and technological success of Abraham loffe Institute in the area of semiconductor heterostructures, and later, nano structures. (Orig../A.B.)

  2. National youth sedentary behavior and physical activity daily patterns using latent class analysis applied to accelerometry.

    Science.gov (United States)

    Evenson, Kelly R; Wen, Fang; Hales, Derek; Herring, Amy H

    2016-05-03

    Applying latent class analysis (LCA) to accelerometry can help elucidated underlying patterns. This study described the patterns of accelerometer-determined sedentary behavior and physical activity among youth by applying LCA to a nationally representative United States (US) sample. Using 2003-2006 National Health and Nutrition Examination Survey data, 3998 youths 6-17 years wore an ActiGraph 7164 accelerometer for one week, providing > =3 days of wear for > =8 h/day from 6:00 am-midnight. Cutpoints defined sedentary behavior ( = 2296 counts/minute), and vigorous activity (> = 4012 counts/minute). To account for wear time differences, outcomes were expressed as percent of day in a given intensity. LCA was used to classify daily (Monday through Sunday) patterns of average counts/minute, sedentary behavior, light activity, MVPA, and vigorous activity separately. The latent classes were explored overall and by age (6-11, 12-14, 15-17 years), gender, and whether or not youth attended school during measurement. Estimates were weighted to account for the sampling frame. For average counts/minute/day, four classes emerged from least to most active: 40.9% of population (mean 323.5 counts/minute/day), 40.3% (559.6 counts/minute/day), 16.5% (810.0 counts/minute/day), and 2.3% (1132.9 counts/minute/day). For percent of sedentary behavior, four classes emerged: 13.5% of population (mean 544.6 min/day), 30.1% (455.1 min/day), 38.5% (357.7 min/day), and 18.0% (259.2 min/day). For percent of light activity, four classes emerged: 12.3% of population (mean 222.6 min/day), 29.3% (301.7 min/day), 41.8% (384.0 min/day), and 16.6% (455.5 min/day). For percent of MVPA, four classes emerged: 59.9% of population (mean 25.0 min/day), 33.3% (60.9 min/day), 3.1% (89.0 min/day), and 3.6% (109.3 min/day). For percent of vigorous activity, three classes emerged: 76.8% of population (mean 7.1 min/day), 18.5% (23.9 min/day), and 4.7% (47.4 min/day). Classes were developed by age

  3. IMOS National Reference Stations: A Continental-Wide Physical, Chemical and Biological Coastal Observing System

    Science.gov (United States)

    Lynch, Tim P.; Morello, Elisabetta B.; Evans, Karen; Richardson, Anthony J.; Rochester, Wayne; Steinberg, Craig R.; Roughan, Moninya; Thompson, Peter; Middleton, John F.; Feng, Ming; Sherrington, Robert; Brando, Vittorio; Tilbrook, Bronte; Ridgway, Ken; Allen, Simon; Doherty, Peter; Hill, Katherine; Moltmann, Tim C.

    2014-01-01

    Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology. PMID:25517905

  4. IMOS National Reference Stations: a continental-wide physical, chemical and biological coastal observing system.

    Directory of Open Access Journals (Sweden)

    Tim P Lynch

    Full Text Available Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS implemented a network of nine National Reference Stations (NRS. The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology.

  5. Novel room temperature ferromagnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Amita [KTH Royal Inst. of Technology, Stockholm (Sweden)

    2004-06-01

    distribution of Mn substituting for Zn a 2+ state in the ZnO lattice. Ferromagnetic Resonance (FMR) technique is used to confirm the existence of ferromagnetic ordering at temperatures as high as 425K. The ab initio calculations were found to be consistent with the observation of ferromagnetism arising from fully polarized Mn 2+ state. The key to observed room temperature ferromagnetism in this system is the low temperature processing, which prevents formation of clusters, secondary phases and the host ZnO from becoming n-type. The electronic structure of the same Mn doped ZnO thin films studied using XAS, XES and RIXS, revealed a strong hybridization between Mn 3d and O 2p states, which is an important characteristic of a Dilute magnetic Semiconductor (DMS). It is shown that the various processing conditions like sintering temperature, dopant concentration and the properties of precursors used for making of DMS have a great influence on the final properties. Use of various experimental techniques to verify the physical properties, and to understand the mechanism involved to give rise to ferromagnetism is presented. Methods to improve the magnetic moment in Mn doped ZnO are also described. New promising DMS materials (such as Cu doped ZnO are explored). The demonstrated new capability to fabricate powder, pellets, and thin films of room temperature ferromagnetic semiconductors thus makes possible the realization of a wide range of complex elements for a variety of new multifunctional phenomena related to Spintronic devices as well as magneto-optic components.

  6. Three dimensional strained semiconductors

    Science.gov (United States)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  7. Optically coupled semiconductor device

    Energy Technology Data Exchange (ETDEWEB)

    Kumagaya, Naoki

    1988-11-18

    This invention concerns an optically coupled semiconductor device using the light as input signal and a MOS transistor for the output side in order to control on-off of the output side by the input signal which is insulated from the output. Concerning this sort of element, when a MOS transistor and a load resistance are planned to be accumulated on the same chip, a resistor and control of impurity concentration of the channel, etc. become necessary despite that the only formation of a simple P-N junction is enough, for a solar cell, hence cost reduction thereof cannot be done. In order to remove this defect, this invention offers an optically coupled semiconductor device featuring that two solar cells are connected in reverse parallel between the gate sources of the output MOS transistors and an operational light emitting element is individually set facing a respective solar cell. 4 figs.

  8. Physical inactivity prevalence and trends among Mexican adults: results from the National Health and Nutrition Survey (ENSANUT) 2006 and 2012.

    Science.gov (United States)

    Medina, Catalina; Janssen, Ian; Campos, Ismael; Barquera, Simón

    2013-11-11

    Lifestyles such as unhealthy diets and the lack of physical activity have been contributed to the increased prevalence of obesity. In 2012, the world health organization published the first global recommendation for physical activity and health. People who do not meet at least 150 minutes of moderate-to-vigorous physical activity are considered to be physically inactive. The prevalence of physical inactivity worldwide is 31%, however there is insufficient data from prevalence and trends of physical inactivity in Mexican population. The purposes of this study are to describe the physical inactivity prevalence and recent trends in Mexican adults and to examine the association between physical inactivity with biologic and sociodemographic characteristics. Representative samples of 17,183 and 10,729 adults (aged 20 to 69 years) who participated in the National Health and Nutrition Survey (ENSANUT) in 2006 and 2012, respectively. Moderate-to-vigorous physical activity (MVPA) was assessed using the short form version of the International Physical Activity Questionnaire (IPAQ), which was administered in face-to-face interviews. Self-reported IPAQ MVPA levels were adjusted using an equation derived from a previous validation study. Participants were considered inactive if they engaged in <150-minutes/week of moderate physical activity or <75 minutes/week of vigorous physical activity according to WHO classification criteria. The prevalence of physical inactivity was significantly higher in 2012 (19.4%, 95% CI: 18.1, 20.7) than in 2006 (13.4%, 95% CI: 12.5, 14.5). Adults in the obese category, 60-69 age group, and those in the highest socioeconomic status tertile were more likely to be physically inactive. The proportion of the Mexican adult population who do not meet the minimum WHO physical activity criteria has increased by 6% points between 2006 and 2012. Given the increasing prevalence of obesity, the aging of the population, and the shift in socioeconomic status in

  9. Doping of organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Luessem, B.; Riede, M.; Leo, K. [Institut fuer Angewandte Photophysik, TU Dresden (Germany)

    2013-01-15

    The understanding and applications of organic semiconductors have shown remarkable progress in recent years. This material class has been developed from being a lab curiosity to the basis of first successful products as small organic LED (OLED) displays; other areas of application such as OLED lighting and organic photovoltaics are on the verge of broad commercialization. Organic semiconductors are superior to inorganic ones for low-cost and large-area optoelectronics due to their flexibility, easy deposition, and broad variety, making tailor-made materials possible. However, electrical doping of organic semiconductors, i.e. the controlled adjustment of Fermi level that has been extremely important to the success of inorganic semiconductors, is still in its infancy. This review will discuss recent work on both fundamental principles and applications of doping, focused primarily to doping of evaporated organic layers with molecular dopants. Recently, both p- and n-type molecular dopants have been developed that lead to efficient and stable doping of organic thin films. Due to doping, the conductivity of the doped layers increases several orders of magnitude and allows for quasi-Ohmic contacts between organic layers and metal electrodes. Besides reducing voltage losses, doping thus also gives design freedom in terms of transport layer thickness and electrode choice. The use of doping in applications like OLEDs and organic solar cells is highlighted in this review. Overall, controlled molecular doping can be considered as key enabling technology for many different organic device types that can lead to significant improvements in efficiencies and lifetimes. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Muonium states in semiconductors

    International Nuclear Information System (INIS)

    Patterson, B.D.

    1987-01-01

    There is a brief summary of what is known about the muonium states isotropic, anisotropic and diamagnetic in diamond and zincblende semiconductors. The report deals with muonium spectroscopy, including the formation probabilities, hyperfine parameters and electronic g-factors of the states. The dynamics of the states is treated including a discussion of the transition from isotropic Mu to anisotropic Mu in diamond, temperature-dependent linewidthes in silicon and germanium and effects of daping and radiation damage

  11. Doping of organic semiconductors

    International Nuclear Information System (INIS)

    Luessem, B.; Riede, M.; Leo, K.

    2013-01-01

    The understanding and applications of organic semiconductors have shown remarkable progress in recent years. This material class has been developed from being a lab curiosity to the basis of first successful products as small organic LED (OLED) displays; other areas of application such as OLED lighting and organic photovoltaics are on the verge of broad commercialization. Organic semiconductors are superior to inorganic ones for low-cost and large-area optoelectronics due to their flexibility, easy deposition, and broad variety, making tailor-made materials possible. However, electrical doping of organic semiconductors, i.e. the controlled adjustment of Fermi level that has been extremely important to the success of inorganic semiconductors, is still in its infancy. This review will discuss recent work on both fundamental principles and applications of doping, focused primarily to doping of evaporated organic layers with molecular dopants. Recently, both p- and n-type molecular dopants have been developed that lead to efficient and stable doping of organic thin films. Due to doping, the conductivity of the doped layers increases several orders of magnitude and allows for quasi-Ohmic contacts between organic layers and metal electrodes. Besides reducing voltage losses, doping thus also gives design freedom in terms of transport layer thickness and electrode choice. The use of doping in applications like OLEDs and organic solar cells is highlighted in this review. Overall, controlled molecular doping can be considered as key enabling technology for many different organic device types that can lead to significant improvements in efficiencies and lifetimes. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  13. Semiconductor Ion Implanters

    International Nuclear Information System (INIS)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-01-01

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  14. Accelerometer-determined physical activity and all-cause mortality in a national prospective cohort study of hypertensive adults.

    Science.gov (United States)

    Loprinzi, Paul D

    2016-05-01

    Research in the general population suggests an inverse association between physical activity and all-cause mortality. Less research on this topic has been conducted among hypertensive adults, but the limited studies also suggest an inverse association between physical activity and all-cause mortality among hypertensive adults. At this point, sex-specific differences are not well understood, and all of the physical activity-mortality studies among hypertensive adults have employed a self-report measure of physical activity. Therefore, the purpose of this study was to examine the sex-specific association between objectively measured physical activity and all-cause mortality among a national sample of hypertensive adults. Data from the 2003 to 2006 National Health and Nutrition Examination Survey, with follow-up through 2011, were employed. Hypertension status was defined using measured blood pressure and use of blood pressure-lowering medication. Physical activity was assessed via accelerometry. After adjustments, for every 60-min increase in physical activity, hypertensive adults had a 19% (hazard rate = 0.81; 95% confidence interval: 0.72-0.91) reduced risk of all-cause mortality. There was also evidence of a dose-response relationship. Compared with those in the lowest tertile, those in the middle and upper tertiles had a 31 and 42% reduced all-cause mortality risk, respectively. There was no evidence of a sex-specific interaction effect. Among hypertensive adults, objectively measured physical activity is associated with all-cause mortality risk in a dose-response manner.

  15. Social background, bullying, and physical inactivity: National study of 11- to 15-year-olds.

    Science.gov (United States)

    Henriksen, P W; Rayce, S B; Melkevik, O; Due, P; Holstein, B E

    2016-10-01

    More children from lower social backgrounds are physically inactive than those from higher ones. We studied whether bullying was a mediating factor between lower social background and physical inactivity. We also examined the combined effect of low social class and exposure to bullying on physical inactivity. The Danish sample of the Health Behaviour in School-aged Children (HBSC) study 2006 included 6269 schoolchildren in three age groups: 11-, 13-, and 15-year-olds from a random sample of 80 schools. The students answered the internationally standardized HBSC questionnaire. The applied definition leaves 4.0% in the category physically inactive. The sex and age-adjusted OR (95% CI) for physical inactivity was 2.10 (1.39-3.18) among students with low social class and unclassifiable 3.53 (2.26-5.53). Exposure to bullying was associated with physical inactivity, sex and age-adjusted OR = 2.39 (1.67-3.41). Exposure to bullying did not explain the association between social class and physical inactivity. The association between social class and physical inactivity was more pronounced among participants also exposed to bullying. In conclusion, there was a significantly increased odds ratio for physical inactivity among students from lower social classes and for students exposed to bullying. There was a combined effect of low social class and bullying on physical inactivity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Physical benefits and reduction of depressive symptoms among the elderly: results from the Portuguese "National Walking Program".

    Science.gov (United States)

    Branco, Jeronimo Costa; Jansen, Karen; Sobrinho, Jessica Teixeira; Carrapatoso, Susana; Spessato, Barbara; Carvalho, Joana; Mota, Jorge; da Silva, Ricardo Azevedo

    2015-03-01

    The aim of this study was to investigate alterations in physical fitness and anthropometric parameters as well as depression symptoms among the elderly after participation in the "National Walking Program" (Portugal). The sample consisted of 26 elderly people over six months with a total of 72 exercise sessions. The exercise sessions consisted of aerobics (walking and running) and strength and flexibility exercises. Participants were assessed pre- and post-intervention for physical fitness with the Rikli & Jones test. The anthropometric measurements were assessed with a bioimpedance scale and a stadiometer, and depression with Yesavage's Geriatric Depression Scale. Physical activity was only assessed with an accelerometer at the pre-intervention phase. For statistical analysis, the student t test for paired samples was performed using SPSS 21 software. Statistically significant improvements were found in depressive symptoms (p ≤ 0.001), and in all physical fitness tests (p ≤ 0.05) except for flexibility tests (p ≥ 0.05). Waist circumference reduction also showed the positive effects of the intervention (p = 0.031). The conclusion drawn is that participation in the "National Walking Program" for 6 months was effective in improving the physical and psychological health of the elderly.

  17. Overview of physics results from the conclusive operation of the National Spherical Torus Experiment

    Science.gov (United States)

    Sabbagh, S. A.; Ahn, J.-W.; Allain, J.; Andre, R.; Balbaky, A.; Bastasz, R.; Battaglia, D.; Bell, M.; Bell, R.; Beiersdorfer, P.; Belova, E.; Berkery, J.; Betti, R.; Bialek, J.; Bigelow, T.; Bitter, M.; Boedo, J.; Bonoli, P.; Boozer, A.; Bortolon, A.; Boyle, D.; Brennan, D.; Breslau, J.; Buttery, R.; Canik, J.; Caravelli, G.; Chang, C.; Crocker, N.; Darrow, D.; Davis, B.; Delgado-Aparicio, L.; Diallo, A.; Ding, S.; D'Ippolito, D.; Domier, C.; Dorland, W.; Ethier, S.; Evans, T.; Ferron, J.; Finkenthal, M.; Foley, J.; Fonck, R.; Frazin, R.; Fredrickson, E.; Fu, G.; Gates, D.; Gerhardt, S.; Glasser, A.; Gorelenkov, N.; Gray, T.; Guo, Y.; Guttenfelder, W.; Hahm, T.; Harvey, R.; Hassanein, A.; Heidbrink, W.; Hill, K.; Hirooka, Y.; Hooper, E. B.; Hosea, J.; Humphreys, D.; Indireshkumar, K.; Jaeger, F.; Jarboe, T.; Jardin, S.; Jaworski, M.; Kaita, R.; Kallman, J.; Katsuro-Hopkins, O.; Kaye, S.; Kessel, C.; Kim, J.; Kolemen, E.; Kramer, G.; Krasheninnikov, S.; Kubota, S.; Kugel, H.; La Haye, R. J.; Lao, L.; LeBlanc, B.; Lee, W.; Lee, K.; Leuer, J.; Levinton, F.; Liang, Y.; Liu, D.; Lore, J.; Luhmann, N., Jr.; Maingi, R.; Majeski, R.; Manickam, J.; Mansfield, D.; Maqueda, R.; Mazzucato, E.; McLean, A.; McCune, D.; McGeehan, B.; McKee, G.; Medley, S.; Meier, E.; Menard, J.; Menon, M.; Meyer, H.; Mikkelsen, D.; Miloshevsky, G.; Mueller, D.; Munsat, T.; Myra, J.; Nelson, B.; Nishino, N.; Nygren, R.; Ono, M.; Osborne, T.; Park, H.; Park, J.; Park, Y. S.; Paul, S.; Peebles, W.; Penaflor, B.; Perkins, R. J.; Phillips, C.; Pigarov, A.; Podesta, M.; Preinhaelter, J.; Raman, R.; Ren, Y.; Rewoldt, G.; Rognlien, T.; Ross, P.; Rowley, C.; Ruskov, E.; Russell, D.; Ruzic, D.; Ryan, P.; Schaffer, M.; Schuster, E.; Scotti, F.; Shaing, K.; Shevchenko, V.; Shinohara, K.; Sizyuk, V.; Skinner, C. H.; Smirnov, A.; Smith, D.; Snyder, P.; Solomon, W.; Sontag, A.; Soukhanovskii, V.; Stoltzfus-Dueck, T.; Stotler, D.; Stratton, B.; Stutman, D.; Takahashi, H.; Takase, Y.; Tamura, N.; Tang, X.; Taylor, G.; Taylor, C.; Tritz, K.; Tsarouhas, D.; Umansky, M.; Urban, J.; Untergberg, E.; Walker, M.; Wampler, W.; Wang, W.; Whaley, J.; White, R.; Wilgen, J.; Wilson, R.; Wong, K. L.; Wright, J.; Xia, Z.; Youchison, D.; Yu, G.; Yuh, H.; Zakharov, L.; Zemlyanov, D.; Zimmer, G.; Zweben, S. J.

    2013-10-01

    Research on the National Spherical Torus Experiment, NSTX, targets physics understanding needed for extrapolation to a steady-state ST Fusion Nuclear Science Facility, pilot plant, or DEMO. The unique ST operational space is leveraged to test physics theories for next-step tokamak operation, including ITER. Present research also examines implications for the coming device upgrade, NSTX-U. An energy confinement time, τE, scaling unified for varied wall conditions exhibits a strong improvement of BTτE with decreased electron collisionality, accentuated by lithium (Li) wall conditioning. This result is consistent with nonlinear microtearing simulations that match the experimental electron diffusivity quantitatively and predict reduced electron heat transport at lower collisionality. Beam-emission spectroscopy measurements in the steep gradient region of the pedestal indicate the poloidal correlation length of turbulence of about ten ion gyroradii increases at higher electron density gradient and lower Ti gradient, consistent with turbulence caused by trapped electron instabilities. Density fluctuations in the pedestal top region indicate ion-scale microturbulence compatible with ion temperature gradient and/or kinetic ballooning mode instabilities. Plasma characteristics change nearly continuously with increasing Li evaporation and edge localized modes (ELMs) stabilize due to edge density gradient alteration. Global mode stability studies show stabilizing resonant kinetic effects are enhanced at lower collisionality, but in stark contrast have almost no dependence on collisionality when the plasma is off-resonance. Combined resistive wall mode radial and poloidal field sensor feedback was used to control n = 1 perturbations and improve stability. The disruption probability due to unstable resistive wall modes (RWMs) was surprisingly reduced at very high βN/li > 10 consistent with low frequency magnetohydrodynamic spectroscopy measurements of mode stability. Greater

  18. Nation

    DEFF Research Database (Denmark)

    Østergaard, Uffe

    2014-01-01

    Nation er et gammelt begreb, som kommer af det latinske ord for fødsel, natio. Nationalisme bygger på forestillingen om, at mennesker har én og kun én national identitet og har ret til deres egen nationalstat. Ordet og forestillingen er kun godt 200 år gammel, og i 1900-tallet har ideologien bredt...

  19. 2016 Final Reports from the Los Alamos National Laboratory Computational Physics Student Summer Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Runnels, Scott Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bachrach, Harrison Ian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carlson, Nils [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Collier, Angela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dumas, William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fankell, Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ferris, Natalie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzalez, Francisco [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Griffith, Alec [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Guston, Brandon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kenyon, Connor [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Benson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mookerjee, Adaleena [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parkinson, Christian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Peck, Hailee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Peters, Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poondla, Yasvanth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rogers, Brandon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shaffer, Nathaniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trettel, Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Valaitis, Sonata Mae [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Venzke, Joel Aaron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Black, Mason [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Demircan, Samet [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Holladay, Robert Tyler [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-22

    The two primary purposes of LANL’s Computational Physics Student Summer Workshop are (1) To educate graduate and exceptional undergraduate students in the challenges and applications of computational physics of interest to LANL, and (2) Entice their interest toward those challenges. Computational physics is emerging as a discipline in its own right, combining expertise in mathematics, physics, and computer science. The mathematical aspects focus on numerical methods for solving equations on the computer as well as developing test problems with analytical solutions. The physics aspects are very broad, ranging from low-temperature material modeling to extremely high temperature plasma physics, radiation transport and neutron transport. The computer science issues are concerned with matching numerical algorithms to emerging architectures and maintaining the quality of extremely large codes built to perform multi-physics calculations. Although graduate programs associated with computational physics are emerging, it is apparent that the pool of U.S. citizens in this multi-disciplinary field is relatively small and is typically not focused on the aspects that are of primary interest to LANL. Furthermore, more structured foundations for LANL interaction with universities in computational physics is needed; historically interactions rely heavily on individuals’ personalities and personal contacts. Thus a tertiary purpose of the Summer Workshop is to build an educational network of LANL researchers, university professors, and emerging students to advance the field and LANL’s involvement in it.

  20. 2015 Final Reports from the Los Alamos National Laboratory Computational Physics Student Summer Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Runnels, Scott Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Caldwell, Wendy [Arizona State Univ., Mesa, AZ (United States); Brown, Barton Jed [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pederson, Clark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Justin [Univ. of California, Santa Cruz, CA (United States); Burrill, Daniel [Univ. of Vermont, Burlington, VT (United States); Feinblum, David [Univ. of California, Irvine, CA (United States); Hyde, David [SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Levick, Nathan [Univ. of New Mexico, Albuquerque, NM (United States); Lyngaas, Isaac [Florida State Univ., Tallahassee, FL (United States); Maeng, Brad [Univ. of Michigan, Ann Arbor, MI (United States); Reed, Richard LeRoy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sarno-Smith, Lois [Univ. of Michigan, Ann Arbor, MI (United States); Shohet, Gil [Univ. of Illinois, Urbana-Champaign, IL (United States); Skarda, Jinhie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stevens, Josey [Missouri Univ. of Science and Technology, Rolla, MO (United States); Zeppetello, Lucas [Columbia Univ., New York, NY (United States); Grossman-Ponemon, Benjamin [Stanford Univ., CA (United States); Bottini, Joseph Larkin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Loudon, Tyson Shane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); VanGessel, Francis Gilbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nagaraj, Sriram [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Price, Jacob [Univ. of Washington, Seattle, WA (United States)

    2015-10-15

    The two primary purposes of LANL’s Computational Physics Student Summer Workshop are (1) To educate graduate and exceptional undergraduate students in the challenges and applications of computational physics of interest to LANL, and (2) Entice their interest toward those challenges. Computational physics is emerging as a discipline in its own right, combining expertise in mathematics, physics, and computer science. The mathematical aspects focus on numerical methods for solving equations on the computer as well as developing test problems with analytical solutions. The physics aspects are very broad, ranging from low-temperature material modeling to extremely high temperature plasma physics, radiation transport and neutron transport. The computer science issues are concerned with matching numerical algorithms to emerging architectures and maintaining the quality of extremely large codes built to perform multi-physics calculations. Although graduate programs associated with computational physics are emerging, it is apparent that the pool of U.S. citizens in this multi-disciplinary field is relatively small and is typically not focused on the aspects that are of primary interest to LANL. Furthermore, more structured foundations for LANL interaction with universities in computational physics is needed; historically interactions rely heavily on individuals’ personalities and personal contacts. Thus a tertiary purpose of the Summer Workshop is to build an educational network of LANL researchers, university professors, and emerging students to advance the field and LANL’s involvement in it. This report includes both the background for the program and the reports from the students.

  1. STRATEGIC PRIORITIES FOR INCREASING PHYSICAL ACTIVITY AMONG ADULTS AGE 50 AND OLDER: THE NATIONAL BLUEPRINT CONSENSUS CONFERENCE SUMMARY REPORT

    Directory of Open Access Journals (Sweden)

    Terry Bazzarre

    2003-12-01

    Full Text Available On May 1, 2001, a coalition of national organizations released a major planning document designed to develop a national strategy for the promotion of physically active lifestyles among the mid-life and older adult population. The National Blueprint: Increasing Physical Activity Among Adults Age 50 and Older was developed with input from 46 organizations with expertise in health, medicine, social and behavioral sciences, epidemiology, gerontology/geriatrics, clinical science, public policy, marketing, medical systems, community organization, and environmental issues. The Blueprint notes that, despite a wealth of evidence about the benefits of physical activity for mid-life and older persons, there has been little success in convincing age 50+ Americans to adopt physically active lifestyles. The Blueprint identifies barriers in the areas of research, home and community programs, medical systems, public policy and advocacy, and marketing and communications. In addition to identifying barriers, the Blueprint proposes a number of concrete strategies that could be employed in order to overcome the barriers to physical activity in society at large. This report summarizes the outcome of the National Blueprint Consensus Conference that was held in October 2002. In this conference, representatives of more than 50 national organizations convened in Washington, D.C. with the goal of identifying high priority and high feasibility strategies which would advance the National Blueprint and which could be initiated within the next 12 to 24 months. Participants in the consensus conference were assigned to one of five breakout groups: home and community, marketing, medical systems, public policy, and research. Each breakout group was charged with identifying the three highest priority strategies within their area for effectively increasing physical activity levels in the mid-life and older adult population. In addition to the 15 strategies identified by the

  2. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  3. Spin Transport in Semiconductor heterostructures

    International Nuclear Information System (INIS)

    Marinescu, Domnita Catalina

    2011-01-01

    The focus of the research performed under this grant has been the investigation of spin transport in magnetic semiconductor heterostructures. The interest in these systems is motivated both by their intriguing physical properties, as the physical embodiment of a spin-polarized Fermi liquid, as well as by their potential applications as spintronics devices. In our work we have analyzed several different problems that affect the spin dynamics in single and bi-layer spin-polarized two-dimensional (2D) systems. The topics of interests ranged from the fundamental aspects of the electron-electron interactions, to collective spin and charge density excitations and spin transport in the presence of the spin-orbit coupling. The common denominator of these subjects is the impact at the macroscopic scale of the spin-dependent electron-electron interaction, which plays a much more subtle role than in unpolarized electron systems. Our calculations of several measurable parameters, such as the excitation frequencies of magneto-plasma modes, the spin mass, and the spin transresistivity, propose realistic theoretical estimates of the opposite-spin many-body effects, in particular opposite-spin correlations, that can be directly connected with experimental measurements.

  4. Participation of the Instituto de Pesquisas Espaciais in the national program for plasma physics and controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    1990-01-01

    This is a report concerning the participation of the Instituto de Pesquisas Espaciais in the national program for plasma physics and controlled thermonuclear fusion. The report lists all the personnel enroled in research activities, both theoretical and experimental. The research subjects are the following: relativistic electron beams; plasma produced by laser; plasma theory; quiescent plasma; plasma centrifugal; ionic propulsion. (A.C.A.S.) [pt

  5. Institute of Geophysics and Planetary Physics (IGPP), Lawrence Livermore National Laboratory (LLNL): Quinquennial report, November 14-15, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Tweed, J.

    1996-10-01

    This Quinquennial Review Report of the Lawrence Livermore National Laboratory (LLNL) branch of the Institute for Geophysics and Planetary Physics (IGPP) provides an overview of IGPP-LLNL, its mission, and research highlights of current scientific activities. This report also presents an overview of the University Collaborative Research Program (UCRP), a summary of the UCRP Fiscal Year 1997 proposal process and the project selection list, a funding summary for 1993-1996, seminars presented, and scientific publications. 2 figs., 3 tabs.

  6. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  7. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  8. Printable semiconductor structures and related methods of making and assembling

    Science.gov (United States)

    Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang; , Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao; Ko, Heung Cho; Mack, Shawn

    2013-03-12

    The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

  9. Modifiable variables in physical therapy education programs associated with first-time and three-year National Physical Therapy Examination pass rates in the United States

    Directory of Open Access Journals (Sweden)

    Chad Cook

    2015-09-01

    Full Text Available Purpose: This study aimed to examine the modifiable programmatic characteristics reflected in the Commission on Accreditation in Physical Therapy Education (CAPTE Annual Accreditation Report for all accredited programs that reported pass rates on the National Physical Therapist Examination, and to build a predictive model for first-time and three-year ultimate pass rates. Methods: This observational study analyzed programmatic information from the 185 CAPTE-accredited physical therapy programs in the United States and Puerto Rico out of a total of 193 programs that provided the first-time and three-year ultimate pass rates in 2011. Fourteen predictive variables representing student selection and composition, clinical education length and design, and general program length and design were analyzed against first-time pass rates and ultimate pass rates on the NPTE. Univariate and multivariate multinomial regression analysis for first-time pass rates and logistic regression analysis for three-year ultimate pass rates were performed. Results: The variables associated with the first-time pass rate in the multivariate analysis were the mean undergraduate grade point average (GPA and the average age of the cohort. Multivariate analysis showed that mean undergraduate GPA was associated with the three-year ultimate pass rate. Conclusions: Mean undergraduate GPA was found to be the only modifiable predictor for both first-time and three-year pass rates among CAPTE-accredited physical therapy programs.

  10. Electrodes for Semiconductor Gas Sensors

    Science.gov (United States)

    Lee, Sung Pil

    2017-01-01

    The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode–semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode–semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect. PMID:28346349

  11. Theory of quantum diffusion in biased semiconductors

    CERN Document Server

    Bryksin, V V

    2003-01-01

    A general theory is developed to describe diffusion phenomena in biased semiconductors and semiconductor superlattices. It is shown that the Einstein relation is not applicable for all field strengths so that the calculation of the field-mediated diffusion coefficient represents a separate task. Two quite different diffusion contributions are identified. The first one disappears when the dipole operator commutes with the Hamiltonian. It plays an essential role in the theory of small polarons. The second contribution is obtained from a quantity that is the solution of a kinetic equation but that cannot be identified with the carrier distribution function. This is in contrast to the drift velocity, which is closely related to the distribution function. A general expression is derived for the quantum diffusion regime, which allows a clear physical interpretation within the hopping picture.

  12. Local adaptation of the National Physical Activity Plan: creation of the Active Living Plan for a Healthier San Antonio.

    Science.gov (United States)

    Esparza, Laura A; Velasquez, Katherine S; Zaharoff, Annette M

    2014-03-01

    Physical inactivity and related health consequences are serious public health threats. Effective strategies to facilitate and support active-living opportunities must be implemented at national, state, and local levels. San Antonio, Texas, health department officials launched the Active Living Council of San Antonio (ALCSA) to engage the community in developing a 3- to 5-year plan to promote active living. A steering committee set preliminary ALCSA aims and established a multisector membership structure modeled after the US National Physical Activity Plan (NPAP). ALCSA adopted governance standards, increased knowledge of physical activity and health, and engaged in an 18-month collaborative master plan writing process. ALCSA selected overarching strategies and evidence-based strategies for each societal sector and adapted strategies to the local context, including tactics, measures of success, and timelines. Community and expert engagement led to a localized plan reflecting national recommendations, the Active Living Plan for a Healthier San Antonio. Multisector collaborations among governmental agencies and community organizations, which were successfully developed in this case to produce the first-ever local adaptation of the NPAP, require clearly defined expectations. Lessons learned in ALCSA's organizational and plan development can serve as a model for future community-driven efforts to increase active living.

  13. Geology of the Source Physics Experiment Site, Climax Stock, Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, M., Prothro, L. B., Obi, C.

    2012-03-15

    A test bed for a series of chemical explosives tests known as Source Physics Experiments (SPE) was constructed in granitic rock of the Climax stock, in northern Yucca Flat at the Nevada National Security Site in 2010-2011. These tests are sponsored by the U.S. Department of Energy, National Nuclear Security Administration's National Center for Nuclear Security. The test series is designed to study the generation and propagation of seismic waves, and will provide data that will improve the predictive capability of calculational models for detecting and characterizing underground explosions. Abundant geologic data are available for the area, primarily as a result of studies performed in conjunction with the three underground nuclear tests conducted in the Climax granite in the 1960s and a few later studies of various types. The SPE test bed was constructed at an elevation of approximately 1,524 meters (m), and consists of a 91.4-centimeter (cm) diameter source hole at its center, surrounded by two rings of three 20.3-cm diameter instrument holes. The inner ring of holes is positioned 10 m away from the source hole, and the outer ring of holes is positioned 20 m from the source hole. An initial 160-m deep core hole was drilled at the location of the source hole that provided information on the geology of the site and rock samples for later laboratory testing. A suite of geophysical logs was run in the core hole and all six instruments holes to obtain matrix and fracture properties. Detailed information on the character and density of fractures encountered was obtained from the borehole image logs run in the holes. A total of 2,488 fractures were identified in the seven boreholes, and these were ranked into six categories (0 through 5) on the basis of their degree of openness and continuity. The analysis presented here considered only the higher-ranked fractures (ranks 2 through 5), of which there were 1,215 (approximately 49 percent of all fractures identified

  14. Association between psoriasis and leisure-time physical activity: findings from the National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Do, Young Kyung; Lakhani, Naheed; Malhotra, Rahul; Halstater, Brian; Theng, Colin; Østbye, Truls

    2015-02-01

    Despite evidence that physical activity can reduce the cardiometabolic risk of patients with psoriasis, these patients may engage in less physical activity than those without psoriasis. The aim of this study was to examine the association of the extent of psoriatic skin lesions with the likelihood of participating in leisure-time moderate to vigorous physical activity (MVPA) and metabolic equivalent task (MET)-minutes of MVPA amongst those who participated. The National Health and Nutrition Examination Survey (NHANES) is a population-based survey among U.S. adults. A total of 6549 persons aged 20-59 years responded to the 2003-2006 NHANES dermatology questionnaires, which asked about participation in leisure-time MVPA and MET-minutes of MVPA amongst those who participated. Compared with individuals without psoriasis, those with psoriasis were less likely to have engaged in leisure MVPA in the past 30 days, although this association was not statistically significant. Amongst those who participated in leisure-time MVPA, MET-minutes of leisure-time MVPA were lower on average for patients currently having few to extensive cutaneous lesions (but not for those currently having little or no psoriatic patches), relative to individuals never diagnosed with psoriasis by approximately 30%. Clinicians should encourage patients with psoriasis, especially those with more severe disease, to be more physically active; they should help identify and address possible psychological and physical barriers to their patients' physical activity. © 2014 Japanese Dermatological Association.

  15. OPENING ADDRESS: Heterostructures in Semiconductors

    Science.gov (United States)

    Grimmeiss, Hermann G.

    1996-01-01

    Good morning, Gentlemen! On behalf of the Nobel Foundation, I should like to welcome you to the Nobel Symposium on "Heterostructures in Semiconductors". It gives me great pleasure to see so many colleagues and old friends from all over the world in the audience and, in particular, to bid welcome to our Nobel laureates, Prof. Esaki and Prof. von Klitzing. In front of a different audience I would now commend the scientific and technological importance of heterostructures in semiconductors and emphatically emphasise that heterostructures, as an important contribution to microelectronics and, hence, information technology, have changed societies all over the world. I would also mention that information technology is one of the most important global key industries which covers a wide field of important areas each of which bears its own character. Ever since the invention of the transistor, we have witnessed a fantastic growth in semiconductor technology, leading to more complex functions and higher densities of devices. This development would hardly be possible without an increasing understanding of semiconductor materials and new concepts in material growth techniques which allow the fabrication of previously unknown semiconductor structures. But here and today I will not do it because it would mean to carry coals to Newcastle. I will therefore not remind you that heterostructures were already suggested and discussed in detail a long time before proper technologies were available for the fabrication of such structures. Now, heterostructures are a foundation in science and part of our everyday life. Though this is certainly true, it is nevertheless fair to say that not all properties of heterostructures are yet understood and that further technologies have to be developed before a still better understanding is obtained. The organisers therefore hope that this symposium will contribute not only to improving our understanding of heterostructures but also to opening new

  16. Development of semiconductor electronics

    International Nuclear Information System (INIS)

    Bardeen, John.

    1977-01-01

    In 1931, Wilson applied Block's theory about the energy bands for the motion of electrons in a crystal lattice to semiconductors and showed that conduction can take place in two different ways, by electrons and by holes. Not long afterwards Frenkel showed that these carriers can flow by diffusion in a concentration gradient as well as under the influence of an electric field and wrote down equations for the current flow. The third major contribution, in the late 1930's was the explanation of rectification at a metalsemiconductor contact by Mott and more completely by Schottky. In late 1947 the first transistor of the point contact type was invented by Brattin, Shockley and Bardeen. Then after single crystals of Ge were grown, the junction transistor was developed by the same group. The first silicon transistors appeared in 1954. Then an important step was discovery of the planar transistor by Hoenri in 1960 which led to development of integrated circuits by 1962. Many transistors are produced by batch processing on a slice of silicon. Then in 1965 Mos (Metal-Oxide Semiconductor) transistor and in 1968 LSI (Large Scale Intergration circuits) were developed. Aside from electronic circuits, there are many other applications of semiconductors, including junction power rectifiers, junction luminescence (including lasers), solar batteries, radiation detectors, microwave oscillators and charged-coupled devices for computer memories and devices. One of the latest developments is a microprocessor with thousands of transistors and associated circuitry on a single small chip of silicon. It can be programmed to provide a variety of circuit functions, thus it is not necessary to go through the great expense of LSI's for each desired function, but to use standard microprocessors and program to do the job

  17. The precarious supply of physical therapists across Canada: exploring national trends in health human resources (1991 to 2005

    Directory of Open Access Journals (Sweden)

    Ricketts Thomas C

    2007-09-01

    Full Text Available Abstract Background Health Human Resource (HHR ratios are one measure of workforce supply, and are often expressed as a ratio in the number of health professionals to a sub-set of the population. In this study, we explore national trends in HHR among physical therapists (PTs across Canada. Methods National population data were combined with provincial databases of registered physical therapists in order to estimate the HHR ratio in 2005, and to establish trends between 1991 and 2005. Results The national HHR ratio was 4.3 PTs per 10,000 population in 1991, which increased to 5.0 by 2000. In 2005, the HHR ratios varied widely across jurisdictions; however, we estimate that the national average dropped to 4.8 PTs per 10,000. Although the trend in HHR between 1991 and 2005 suggests positive growth of 11.6%, we have found negative growth of 4.0% in the latter 5-years of this study period. Conclusion Demand for rehabilitation services is projected to escalate in the next decade. Identifying benchmarks or targets regarding the optimal number of PTs, along with other health professionals working within inter professional teams, is necessary to establish a stable supply of health providers to meet the emerging rehabilitation and mobility needs of an aging and increasingly complex Canadian population.

  18. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  19. Electrowetting on semiconductors

    Science.gov (United States)

    Palma, Cesar; Deegan, Robert

    2015-01-01

    Applying a voltage difference between a conductor and a sessile droplet sitting on a thin dielectric film separating it from the conductor will cause the drop to spread. When the conductor is a good metal, the change of the drop's contact angle due to the voltage is given by the Young-Lippmann (YL) equation. Here, we report experiments with lightly doped, single crystal silicon as the conductive electrode. We derive a modified YL equation that includes effects due to the semiconductor and contact line pinning. We show that light induces a non-reversible wetting transition, and that our model agrees well with our experimental results.

  20. Semiconductor ionizino. radiation detectors

    International Nuclear Information System (INIS)

    1982-01-01

    Spectrometric semiconductor detectors of ionizing radiation with the electron-hole junction, based on silicon and germanium are presented. The following parameters are given for the individual types of germanium detectors: energy range of detected radiation, energy resolution given as full width at half maximum (FWHM) and full width at one tenth of maximum (FWTM) for 57 Co and 60 Co, detection sensitivity, optimal voltage, and electric capacitance at optimal voltage. For silicon detectors the value of FWHM for 239 Pu is given, the sensitive area and the depth of the sensitive area. (E.S.)

  1. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M

    2013-01-01

    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  2. PHYSICS

    CERN Multimedia

    Submitted by

    Physics Week: plenary meeting on physics groups plans for startup (14–15 May 2008) The Physics Objects (POG) and Physics Analysis (PAG) Groups presented their latest developments at the plenary meeting during the Physics Week. In the presentations particular attention was given to startup plans and readiness for data-taking. Many results based on the recent cosmic run were shown. A special Workshop on SUSY, described in a separate section, took place the day before the plenary. At the meeting, we had also two special DPG presentations on “Tracker and Muon alignment with CRAFT” (Ernesto Migliore) and “Calorimeter studies with CRAFT” (Chiara Rovelli). We had also a report from Offline (Andrea Rizzi) and Computing (Markus Klute) on the San Diego Workshop, described elsewhere in this bulletin. Tracking group (Boris Mangano). The level of sophistication of the tracking software increased significantly over the last few months: V0 (K0 and Λ) reconstr...

  3. Association of Physical Activity with Alcohol Abuse and Dependence in a Nationally-Representative U.S. Sample.

    Science.gov (United States)

    Damian, April Joy; Mendelson, Tamar

    2017-11-10

    Alcohol use is a pervasive and costly public health problem in the United States. Relapse rates from alcohol use disorders are high. Although exercise has been proposed as a strategy to prevent relapse, lifestyle modification is the least studied aspect of relapse prevention programs, especially among racial/ethnic minority populations. The current study assessed whether being physically active was associated with remission from alcohol abuse or dependence among Black (African American and Afro Caribbean) adults in the U.S. We utilized data on Black adult participants (n = 4,828) from the nationally representative National Survey of American Life (NSAL) conducted in 2001-2003. Logistic regression models were estimated to assess the odds of being in 12-month remission or currently meeting DSM-IV criteria for alcohol abuse or dependence based on level of physical activity, adjusting for socio-demographic and neighborhood characteristics. People who endorsed being physically active had higher odds of being in 12-month remission from alcohol use problems (OR: 1.67, 95% CI: 1.28, 2.17) than people who were physically inactive, adjusting for individual- and neighborhood-level characteristics. People who were physically active did not differ significantly from those who were inactive with respect to odds of currently meeting DSM-IV criteria for alcohol abuse or dependence. Conclusions/Importance: Physical activity was positively associated with being in 12-month remission from alcohol use problems. Longitudinal studies are needed to establish temporal ordering and to explore exercise as a potential relapse prevention strategy for alcohol use problems.

  4. Processes and Instructions Encouraging Thai Students Consistently Pass the First Round of The National Physics Academics Olympiads

    Science.gov (United States)

    Teevasuthornsakul, Chalongchai; Manosuttirit, Artnarong; Suwanno, Chirasak; Sutsaguan, Lanchakorn

    2010-07-01

    This research focused on the processes and physics instruction of 25 schools located in Bangkok and up-country in Thailand in order to explain why many of their students have passed the first round of the National Physics Academic Olympiads consistently. The high schools in Thailand can apply and support their students and develop their potential in physics. The development of physics professional is the cornerstone of a developing country and increase physics quality base on sciences development in the future in Thailand. The duration of collecting all data was from May 2007 to May 2009. The methodology for this research was the qualitative research method. The researchers interviewed managers, teachers and students at each school location or used semi-structured interview forms. The researchers used the Investigator Triangulation approach to check the qualitative data and the Cause and Effect Analysis approach to analyze situation factors. The results showed that in processes were include 1) enhanced the students with the Academic Olympiads to develop the capacities of students; 2) motivated the students with processes such as good instruction in physics and special privilege in continuing studies in university; and 3) tutorial systems and drill and practice systems support students into subsequent rounds. 4) Admiration activities accommodated the students continually and suitably. Most of the teaching styles used in their lectures, in both basic contents and practice, encouraged students to analyze entrance examination papers, little laboratory. While students say that" They just know that a physics laboratory is very important to study physics after they passed Olympic camp."

  5. Proceedings of the 8. National Meeting of Particle Physics and Fields - Abstracts

    International Nuclear Information System (INIS)

    1987-01-01

    The results of the research programs developed in Particle Physics and Field Theory in 1987 are presented. Review lectures on the main lines of research on the subject are also presented. (M.W.O.) [pt

  6. LOW-ENERGY NUCLEAR PHYSICS NATIONAL HPC INITIATIVE: BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL (UNEDF)

    Energy Technology Data Exchange (ETDEWEB)

    Bulgac, A

    2013-03-27

    This document is a summary of the physics research carried out by the University of Washington centered group. Attached are reports for the previous years as well as the full exit report of the entire UNEDF collaboration.

  7. Activities of the theoretical nuclear physics group of the Atomic Energy National Commission

    International Nuclear Information System (INIS)

    Reich, S.L.

    1982-01-01

    The theoretical studies that have been made in the Atomic Energy National Commission of Argentina about nuclear reactions, nuclear field theories, boson techniques and Hartree-Fock approximation, etc., are reported. (L.C.) [pt

  8. Distance to green space and physical activity: a danish national representative survey

    DEFF Research Database (Denmark)

    Toftager, Mette; Ekholm, Ola; Schipperijn, Jasper

    2011-01-01

    This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated.......This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated....

  9. Child physical and sexual abuse: a comprehensive look at alcohol consumption patterns, consequences, and dependence from the National Alcohol Survey.

    Science.gov (United States)

    Lown, E Anne; Nayak, Madhabika B; Korcha, Rachael A; Greenfield, Thomas K

    2011-02-01

    Previous research has documented a relationship between child sexual abuse and alcohol dependence. This paper extends that work by providing a comprehensive description of past year and lifetime alcohol consumption patterns, consequences, and dependence among women reporting either physical and sexual abuse in a national sample. This study used survey data from 3,680 women who participated in the 2005 U.S. National Alcohol Survey. Information on physical and sexual child abuse and its characteristics were assessed in relation to 8 past year and lifetime alcohol consumption measures. Child physical or sexual abuse was significantly associated with past year and lifetime alcohol consumption measures. In multivariate analyses, controlling for age, marital status, employment status, education, ethnicity, and parental alcoholism or problem drinking, women reporting child sexual abuse vs. no abuse were more likely to report past year heavy episodic drinking (OR(adj) = 1.7; 95% CI 1.0 to 2.9), alcohol dependence (OR(adj) = 7.2; 95% CI 3.2 to 16.5), and alcohol consequences (OR(adj) = 3.6; 95% CI 1.8 to 7.3). Sexual abuse (vs. no abuse) was associated with a greater number of past year drinks (124 vs. 74 drinks, respectively, p = 0.002). Sexual child abuse was also associated with lifetime alcohol-related consequences (OR(adj) = 3.5; 95% CI 2.6 to 4.8) and dependence (OR(adj) = 3.7; 95% CI 2.6 to 5.3). Physical child abuse was associated with 4 of 8 alcohol measures in multivariate models. Both physical and sexual child abuse were associated with getting into fights, health, legal, work, and family alcohol-related consequences. Alcohol-related consequences and dependence were more common for women reporting sexual abuse compared to physical abuse, 2 or more physical abuse perpetrators, nonparental and nonfamily physical abuse perpetrators, and women reporting injury related to the abuse. Both child physical and sexual abuse were associated with many alcohol outcomes in

  10. Physical properties of metal–insulator–semiconductor structures based on n-GaAs with InAs quantum dots deposited onto the surface of an n-GaAs layer

    Energy Technology Data Exchange (ETDEWEB)

    Tikhov, S. V.; Gorshkov, O. N.; Koryazhkina, M. N., E-mail: mahavenok@mail.ru; Kasatkin, A. P.; Antonov, I. N.; Vihrova, O. V.; Morozov, A. I. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation)

    2016-12-15

    The properties of metal–insulator–semiconductor (MIS) structures based on n-GaAs in which silicon oxide and yttria-stabilized zirconia and hafnia are used as the insulator containing InAs quantum dots, which are embedded at the insulator/n-GaAs interface, are investigated. The structures manifest the resistive switching and synaptic behavior.

  11. Single filament semiconductor laser

    International Nuclear Information System (INIS)

    Botez, D.

    1980-01-01

    A semiconductor laser comprising: a body of semiconductor material including a substrate having a surface and a pair of spaced, substantially parallel dove-tailed shaped grooves in said surface, said body having a pair of end surfaces between which said grooves extend, said end surfaces being reflective to light with at least one of said end surfaces being partially transparent to light a first epitaxial layer over said surface of the substrate and the surfaces of the grooves, said first epitaxial layer having a flat surface portion over the portion of the substrate surface between the grooves, a thin second epitaxial layer over said first epitaxial layer, a third epitaxial layer over said second epitaxial layer, said first and third epitaxial layers being of opposite conductivity types and the second epitaxial layer being the active recombination region of the laser with the light being generated therein in the vicinity of the portion which is over the flat surface portion of the first epitaxial layer, and a pair of contacts on said body with one contact being over said third epitaxial body and the other being on said substrate

  12. Semiconductor micro cavities: half light, half matter

    International Nuclear Information System (INIS)

    Baumberg, Jeremy J.

    2003-01-01

    Quantum wells sandwiched tightly between two mirrors can be used to make a new type of laser that can amplify light more than any other known material. What do you get if you cross light with matter? It is a question that fascinates today's researchers in quantum optoelectronics, who want to see how far the physical states of the world can be intertwined. Although we have a good understanding of the quantum ingredients of optics and solids - photons and atoms - it turns out that assembling these building blocks in deliberately unfamiliar ways can lead to what is new and often quite unexpected behaviour. Consider 'quantum wells', which form the basis of modern semiconductor lasers. First developed in the 1980s, they lie at the heart of optical-communication and optical-storage technologies such as DVD players and they now have a global market of over 10bn British Pounds. Quantum wells consist of a thin sheet of crystalline semiconductor sandwiched between two sheets of another semiconductor. The outer layers squash the wavefunctions of electrons within the central sheet, increasing the electrons' energy and their interaction with light. Engineers can control the colour of the light emitted by the laser simply by adjusting the energy levels within the central sheet, which acts as a potential well. But this bug-sized playground for electrons has not just had technological ramifications. It has also spawned an enormous variety of new physics, including the quantum Hall effect, which can be used as a fundamental standard for measuring the ratio between the charge on the electron and the Planck constant. Over the last ten years researchers have also become increasingly keen to incorporate quantum wells into what are known as 'semiconductor micro cavities'. Physicists have found that these painstakingly layered materials can be used to create new quantum states that resemble superfluids and can be used in interferometric quantum devices. In the March issue of Physics

  13. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  14. Quantum transport in semiconductor nanowires

    NARCIS (Netherlands)

    Van Dam, J.

    2006-01-01

    This thesis describes a series of experiments aimed at understanding the low-temperature electrical transport properties of semiconductor nanowires. The semiconductor nanowires (1-100 nm in diameter) are grown from nanoscale gold particles via a chemical process called vapor-liquid-solid (VLS)

  15. Semiconductor photocatalysis principles and applications

    CERN Document Server

    Kisch, Horst

    2014-01-01

    Focusing on the basic principles of semiconductor photocatalysis, this book also gives a brief introduction to photochemistry, photoelectrochemistry, and homogeneous photocatalysis. In addition, the author - one of the leading authorities in the field - presents important environmental and practical aspects. A valuable, one-stop source for all chemists, material scientists, and physicists working in this area, as well as novice researchers entering semiconductor photocatalysis.

  16. Progress in semiconductor drift detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Walton, J.; Gatti, E.

    1985-01-01

    Progress in testing semiconductor drift detectors is reported. Generally better position and energy resolutions were obtained than resolutions published previously. The improvement is mostly due to new electronics better matched to different detectors. It is shown that semiconductor drift detectors are becoming versatile and reliable detectors for position and energy measurements

  17. Optical coherent control in semiconductors

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    of quantum control including the recent applications to semiconductors and nanostructures. We study the influence of inhomogeneous broadening in semiconductors on CC results. Photoluminescence (PL) and the coherent emission in four-wave mixing (FWM) is recorded after resonant excitation with phase...

  18. Terahertz Nonlinear Optics in Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias C.

    2013-01-01

    We demonstrate the nonlinear optical effects – selfphase modulation and saturable absorption of a single-cycle THz pulse in a semiconductor. Resulting from THz-induced modulation of Drude plasma, these nonlinear optical effects, in particular, lead to self-shortening and nonlinear spectral...... breathing of a single-cycle THz pulse in a semiconductor....

  19. Physical fitness and injury reporting among active duty and National Guard/Reserve women: associations with risk and lifestyle factors.

    Science.gov (United States)

    Kazman, Josh B; de la Motte, Sarah; Bramhall, Elizabeth M S; Purvis, Dianna L; Deuster, Patricia A

    2015-01-01

    As more women enter the military, it is important to understand how different risks and lifestyle factors influence physical fitness and injury among women in both active duty (AD) and National Guard/Reserve (NG/R). Women in military service are less fit and more likely to suffer musculoskeletal injuries during physical training than men. They also use more medical care during deployment than men. Using data from the Comprehensive Soldier and Family Fitness Global Assessment Tool 2.0 (GAT 2.0), self-reported health and lifestyle and behavioral risk factors were analyzed in nondeployed Army personnel, with the goals of examining (1) service-component differences across traditional risk and lifestyle factors, and (2) correlates of physical performance and physical activity-related injury. Self-report GAT 2.0 data included health risk factors (overall perceived health, sleep, diet, tobacco and alcohol use), self-reported health metrics (height, weight, Army Physical Fitness Test (APFT) scores), and history of physical activity-related injury. The GAT 2.0 was completed by 1,322 AD and 1,033 NG/R women, and APFT data were available for a subsample of 605 AD and 582 NG/R women. Initial analyses of GAT 2.0 data indicated that AD had higher rates of fair/poor perceived health, poor sleep, and unhealthy diet compared to NG/R women. However, AD women had a lower APFT fail rate (8%) than NG (27%) and R (28%). Active duty women were more likely to experience a physical injury in the past 6 months (38%) than NG (19%) and R (22%) women, and more likely to seek medical care than NG/R women. Across all service components, predictive factors for APFT failure included high body mass index (BMI), fair/poor health, and unhealthy diet. Predictive factors for physical injury included high BMI, fair/poor health, and binge drinking. Our analyses suggest that AD women Soldiers are more physically fit than NG/R women Soldiers, which is accompanied by a greater prevalence of physical

  20. Participation in Types of Physical Activities Among US Adults--National Health and Nutrition Examination Survey 1999-2006.

    Science.gov (United States)

    Dai, Shifan; Carroll, Dianna D; Watson, Kathleen B; Paul, Prabasaj; Carlson, Susan A; Fulton, Janet E

    2015-06-01

    Information on specific types of physical activities in which US adults participate is important for community and program development to promote physical activity. Prevalence of participation and average time spent for 33 leisure-time aerobic activities and 10 activity categories were calculated using self-reported data from 22,545 participants aged ≥ 18 years in the National Health and Nutrition Examination Survey 1999-2006. Overall, 38% of US adults reported no leisure-time physical activities, and 43% reported 1 or 2 activities in the past 30 days. Walking was the most frequently reported activity for both men (29%) and women (38%). Among walkers, the average time spent walking was 198 minutes/week for men and 152 minutes/week for women. The most reported activities for men after walking were bicycling and yard work, and for women were aerobics and dance. For most activity categories, participation was lower among adults aged ≥ 65 years than among younger adults, and among Mexican Americans and non-Hispanic blacks than among non-Hispanic whites. Participation in most categories increased with increasing educational attainment. Participation in physical activity differs by types of activities and demographic characteristics. Physical activity promotion programs should take these differences into account when developing intervention strategies.

  1. Time trends in leisure time physical activity and physical fitness in the elderly: five-year follow-up of the Spanish National Health Survey (2006-2011).

    Science.gov (United States)

    Casado-Pérez, Carmen; Hernández-Barrera, Valentín; Jiménez-García, Rodrigo; Fernández-de-las-Peñas, Cesar; Carrasco-Garrido, Pilar; López-de-Andrés, Ana; Jimenez-Trujillo, Ma Isabel; Palacios-Ceña, Domingo

    2015-04-01

    To estimate the trends in the practice of leisure time physical activity, walking up 10 steps, and walking for 1h, during the years 2006-2011, in elderly Spanish people. Observational study, retrospective analysis of Spanish National Health Surveys. We analysed data collected from the Spanish National Health Surveys conducted in 2006 (n=30,072) and 2011 (n=21,007), through self-reported information. The number of subjects aged ≥65 years included in the current study was n=5756 in 2006 (19.14%) and n=4617 in 2011 (21.97%). We included responses from adults aged 65 years and older. The main variables included leisure-time physical activity, walking up 10 steps, and walking for 1h. We analysed socio-demographic characteristics, individuals' self-rated health status, lifestyle habits, co-morbid conditions and disability using multivariable logistic regression models. The total number of subjects was 10,373 (6076 women, 4297 men). The probability of self-reported capacity was significantly higher in 2006 than in 2011 for leisure-time physical activity, walking up 10 steps, and walking for 1h for both sexes (women: OR 2.20, 95%IC 1.91-5.55; OR 2.50, 95%IC 1.99-3.14; OR 1.04, 95%IC 1.01-1.07; men: OR 2.20, 95%IC 1.91-2.55; OR 2.01, 95%IC 1.40-2.89; OR 1.05, 95%IC 1.0-1.1) respectively. Both sexes were associated with a significantly lower probability of performing leisure-time physical activity, walking up 10 steps, and walking for 1h. Additionally, those over 80 years of age, on average, showed a poor or very poor perception of their health and presented with some type of disability. A decrease in the proportion of respondents who self-reported undertaking leisure-time physical activity, walking up 10 steps, and walking for 1h was observed in the Spanish population of over 65 years between 2006 and 2011. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.  Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish how ready we are to do physics with the early collisions at the LHC. The agenda of the week was thus pac...

  3. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.   Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish (we hoped) the readiness of CMS to do physics with the early collisions at the LHC. The agenda of the...

  4. National physical activity surveillance: Users of wearable activity monitors as a potential data source

    Directory of Open Access Journals (Sweden)

    John D. Omura, MD

    2017-03-01

    Full Text Available The objective of this study was to assess usage patterns of wearable activity monitors among US adults and how user characteristics might influence physical activity estimates from this type of sample. We analyzed data on 3367 respondents to the 2015 HealthStyles survey, an annual consumer mail panel survey conducted on a nationwide sample. Approximately 1 in 8 respondents (12.5% reported currently using a wearable activity monitor. Current use varied by sex, age, and education level. Use increased with physical activity level from 4.3% for inactive adults to 17.4% for active adults. Overall, 49.9% of all adults met the aerobic physical activity guideline, while this prevalence was 69.5% among current activity monitor users. Our findings suggest that current users of wearable activity monitors are not representative of the overall US population. Estimates of physical activity levels using data from wearable activity monitors users may be an overestimate and therefore data from users alone may have a limited role in physical activity surveillance.

  5. Organic semiconductors in a spin

    CERN Document Server

    Samuel, I

    2002-01-01

    A little palladium can go a long way in polymer-based light-emitting diodes. Inorganic semiconductors such as silicon and gallium arsenide are essential for countless applications in everyday life, ranging from PCs to CD players. However, while they offer unrivalled computational speed, inorganic semiconductors are also rigid and brittle, which means that they are less suited to applications such as displays and flexible electronics. A completely different class of materials - organic semiconductors - are being developed for these applications. Organic semiconductors have many attractive features: they are easy to make, they can emit visible light, and there is tremendous scope for tailoring their properties to specific applications by changing their chemical structure. Research groups and companies around the world have developed a wide range of organic-semiconductor devices, including transistors, light-emitting diodes (LEDs), solar cells and lasers. (U.K.)

  6. Risk factors for domestic physical violence: national cross-sectional household surveys in eight southern African countries

    Directory of Open Access Journals (Sweden)

    Mitchell Steve

    2007-07-01

    Full Text Available Abstract Background The baseline to assess impact of a mass education-entertainment programme offered an opportunity to identify risk factors for domestic physical violence. Methods In 2002, cross-sectional household surveys in a stratified urban/rural last-stage random sample of enumeration areas, based on latest national census in Botswana, Lesotho, Malawi, Mozambique, Namibia, Swaziland, Zambia and Zimbabwe. Working door to door, interviewers contacted all adults aged 16–60 years present on the day of the visit, without sub-sampling. 20,639 adults were interviewed. The questionnaire in 29 languages measured domestic physical violence by the question "In the last year, have you and your partner had violent arguments where your partner beat, kicked or slapped you?" There was no measure of severity or frequency of physical violence. Results 14% of men (weighted based on 1,294/8,113 and 18% of women (weighted based on 2,032/11,063 reported being a victim of partner physical violence in the last year. There was no convincing association with age, income, education, household size and remunerated occupation. Having multiple partners was strongly associated with partner physical violence. Other associations included the income gap within households, negative attitudes about sexuality (for example, men have the right to sex with their girlfriends if they buy them gifts and negative attitudes about sexual violence (for example, forcing your partner to have sex is not rape. Particularly among men, experience of partner physical violence was associated with potentially dangerous attitudes to HIV infection. Conclusion Having multiple partners was the most consistent risk factor for domestic physical violence across all countries. This could be relevant to domestic violence prevention strategies.

  7. All-metal coupling and package of semiconductor laser and amplifier with optical fiber

    International Nuclear Information System (INIS)

    Xu Fenglan; Li Lina; Zhang Yueqing

    1992-01-01

    The semiconductor laser and optical amplifier made by Changchun Institute of Physics coupled with optical fiber by use of all-metal coupling are represented. The net gain of semiconductor laser amplifier with optical fiber is 14 ∼18 dB

  8. Educating Tomorrow's Workforce: A Report on the Semiconductor Industry's Commitment to Youth in K-12.

    Science.gov (United States)

    Semiconductor Industry Association, San Jose, CA.

    The U.S. semiconductor industry, now the nation's largest manufacturing industry, displays its commitment to training its current workers and educating future workers by supporting educational efforts on the K-12 level. This catalog describes innovative actions by 16 Semiconductor Industry Association companies to improve education at the K-12…

  9. The CERN-JINR Joint Physics Schools Exhibition Science Bringing Nations Together

    CERN Multimedia

    1997-01-01

    Since 1970, CERN and JINR have been holding joint Schools of Physics attended by young scientists from many countries of the world. Here they not only learn the latest ideas in elementary particle physics but also become involved in a process that leads to better mutual understanding and rapprochement of people from different countries. Such schools may seem natural natural now, but long before the Berlin Wall and the Iron Curtain collapsed, they provided a unique opportunity for contact between young people from countries with different political systems. This long-standing co-operation between CERN and JINR helps to bridge the gap between East and West and stabilize the political situation.

  10. The CERN-JINR Joint Physics Schools Exhibition Science Bringing Nations Together

    CERN Multimedia

    1999-01-01

    Since 1970, CERN and JINR have been holding joint Schools of Physics attended by young scientists from many countries of the world. Here they not only learn the latest ideas in elementary particle physics but also become involved in a process that leads to better mutual understanding and rapprochement of people from different countries. Such schools may seem natural now, but long before the Berlin Wall and the Iron Curtain collapsed, they provided a unique opportunity for contact between young people from countries with different political systems. This long-standing co-operation between CERN and JINR helps to bridge the gap between East and West and stabilize the political situation.

  11. An Overview of the Computational Physics and Methods Group at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Randal Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-02-22

    CCS Division was formed to strengthen the visibility and impact of computer science and computational physics research on strategic directions for the Laboratory. Both computer science and computational science are now central to scientific discovery and innovation. They have become indispensable tools for all other scientific missions at the Laboratory. CCS Division forms a bridge between external partners and Laboratory programs, bringing new ideas and technologies to bear on today’s important problems and attracting high-quality technical staff members to the Laboratory. The Computational Physics and Methods Group CCS-2 conducts methods research and develops scientific software aimed at the latest and emerging HPC systems.

  12. Features of the electric-field distribution in anisotropic semiconductor wafers in a transverse magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Filippov, V. V., E-mail: wwfilippow@mail.ru [Lipetsk State Pedagogical University (Russian Federation); Bormontov, E. N. [Voronezh State University (Russian Federation)

    2013-07-15

    A macroscopic model of the Hall effects and magnetoresistance in anisotropic semiconductor wafers is developed. The results obtained by solving the electrodynamic boundary problem allow the potential and eddy currents in anisotropic semiconductors to be calculated at different current-contact locations, depending on the parameters of the sample material's anisotropy. The results of this study are of great practical importance for investigating the physical properties of anisotropic semiconductors and simulating the electron-transport phenomena in devices based on anisotropic semiconductors.

  13. Features of the electric-field distribution in anisotropic semiconductor wafers in a transverse magnetic field

    International Nuclear Information System (INIS)

    Filippov, V. V.; Bormontov, E. N.

    2013-01-01

    A macroscopic model of the Hall effects and magnetoresistance in anisotropic semiconductor wafers is developed. The results obtained by solving the electrodynamic boundary problem allow the potential and eddy currents in anisotropic semiconductors to be calculated at different current-contact locations, depending on the parameters of the sample material’s anisotropy. The results of this study are of great practical importance for investigating the physical properties of anisotropic semiconductors and simulating the electron-transport phenomena in devices based on anisotropic semiconductors

  14. Ion implantation for semiconductors

    International Nuclear Information System (INIS)

    Grey-Morgan, T.

    1995-01-01

    Full text: Over the past two decades, thousands of particle accelerators have been used to implant foreign atoms like boron, phosphorus and arsenic into silicon crystal wafers to produce special embedded layers for manufacturing semiconductor devices. Depending on the device required, the atomic species, the depth of implant and doping levels are the main parameters for the implantation process; the selection and parameter control is totally automated. The depth of the implant, usually less than 1 micron, is determined by the ion energy, which can be varied between 2 and 600 keV. The ion beam is extracted from a Freeman or Bernas type ion source and accelerated to 60 keV before mass analysis. For higher beam energies postacceleration is applied up to 200 keV and even higher energies can be achieved by mass selecting multiplycharged ions, but with a corresponding reduction in beam output. Depending on the device to be manufactured, doping levels can range from 10 10 to 10 15 atoms/cm 2 and are controlled by implanter beam currents in the range up to 30mA; continuous process monitoring ensures uniformity across the wafer of better than 1 % . As semiconductor devices get smaller, additional sophistication is required in the design of the implanter. The silicon wafers charge electrically during implantation and this charge must be dissipated continuously to reduce the electrical stress in the device and avoid destructive electrical breakdown. Electron flood guns produce low energy electrons (below 10 electronvolts) to neutralize positive charge buildup and implanter design must ensure minimum contamination by other isotopic species and ensure low internal sputter rates. The pace of technology in the semiconductor industry is such that implanters are being built now for 256 Megabit circuits but which are only likely to be widely available five years from now. Several specialist companies manufacture implanter systems, each costing around US$5 million, depending on the

  15. PHYSICS

    CERN Multimedia

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  16. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  17. Self Organization in Compensated Semiconductors

    Science.gov (United States)

    Berezin, Alexander A.

    2004-03-01

    In partially compensated semiconductor (PCS) Fermi level is pinned to donor sub-band. Due to positional randomness and almost isoenergetic hoppings, donor-spanned electronic subsystem in PCS forms fluid-like highly mobile collective state. This makes PCS playground for pattern formation, self-organization, complexity emergence, electronic neural networks, and perhaps even for origins of life, bioevolution and consciousness. Through effects of impact and/or Auger ionization of donor sites, whole PCS may collapse (spinodal decomposition) into microblocks potentially capable of replication and protobiological activity (DNA analogue). Electronic screening effects may act in RNA fashion by introducing additional length scale(s) to system. Spontaneous quantum computing on charged/neutral sites becomes potential generator of informationally loaded microstructures akin to "Carl Sagan Effect" (hidden messages in Pi in his "Contact") or informational self-organization of "Library of Babel" of J.L. Borges. Even general relativity effects at Planck scale (R.Penrose) may affect the dynamics through (e.g.) isotopic variations of atomic mass and local density (A.A.Berezin, 1992). Thus, PCS can serve as toy model (experimental and computational) at interface of physics and life sciences.

  18. The cost of physical inactivity to a nation: the role of sports medicine ...

    African Journals Online (AJOL)

    cost up to $1 trillion in health care and lost production costs. Physi- cal inactivity ... than physical exercise to reduce the risk of virtually all chronic diseases'. ... and the dissemination of a clear, simple, yet effective message. 5. The Agita São ...

  19. Legacy tree data: A national database of detailed tree measurements for volume, weight, and physical properties

    Science.gov (United States)

    P.J. Radtke; D.M. Walker; A.R. Weiskittel; J. Frank; J.W. Coulston; J.A. Westfall

    2015-01-01

    Forest mensurationists in the United States have expended considerable effort over the past century making detailed observations of trees’ dimensions. In recent decades efforts have focused increasingly on weights and physical properties. Work is underway to compile original measurements from past volume, taper, and weight or biomass studies for North American tree...

  20. Talent Development in Physical Education: A National Survey of Policy and Practice in England

    Science.gov (United States)

    Bailey, Richard; Morley, David; Dismore, Harriet

    2009-01-01

    Background: Although there has been a great deal of research on talent development in sport and education, there has been a distinct lack of research on developing talent specifically in a curricular physical education context. Yet, all schools in England are expected to identify and support their talented pupils. Purpose: In order to investigate…

  1. Physics

    CERN Document Server

    Cullen, Katherine

    2005-01-01

    Defined as the scientific study of matter and energy, physics explains how all matter behaves. Separated into modern and classical physics, the study attracts both experimental and theoretical physicists. From the discovery of the process of nuclear fission to an explanation of the nature of light, from the theory of special relativity to advancements made in particle physics, this volume profiles 10 pioneers who overcame tremendous odds to make significant breakthroughs in this heavily studied branch of science. Each chapter contains relevant information on the scientist''s childhood, research, discoveries, and lasting contributions to the field and concludes with a chronology and a list of print and Internet references specific to that individual.

  2. Use of physical restraints and antipsychotic medications in nursing homes: a cross-national study.

    Science.gov (United States)

    Feng, Zhanlian; Hirdes, John P; Smith, Trevor F; Finne-Soveri, Harriet; Chi, Iris; Du Pasquier, Jean-Noel; Gilgen, Ruedi; Ikegami, Naoki; Mor, Vincent

    2009-10-01

    This study compares inter- and intra-country differences in the prevalence of physical restraints and antipsychotic medications in nursing homes, and examines aggregated resident conditions and organizational characteristics correlated with these treatments. Population-based, cross-sectional data were collected using a standardized Resident Assessment Instrument (RAI) from 14,504 long-term care facilities providing nursing home level services in five countries participating in the interRAI consortium, including Canada, Finland, Hong Kong (Special Administrative Region, China), Switzerland, and the United States. Facility-level prevalence rates of physical restraints and antipsychotic use were examined both between and within the study countries. The prevalence of physical restraint use varied more than five-fold across the study countries, from an average 6% in Switzerland, 9% in the US, 20% in Hong Kong, 28% in Finland, and over 31% in Canada. The prevalence of antipsychotic use ranged from 11% in Hong Kong, between 26-27% in Canada and the US, 34% in Switzerland, and nearly 38% in Finland. Within each country, substantial variations existed across facilities in both physical restraint and antipsychotic use rates. In all countries, neither facility case mix nor organizational characteristics were particularly predictive of the prevalence of either treatment. There exists large, unexplained variability in the prevalence of physical restraint and antipsychotic use in nursing home facilities both between and within countries. Since restraints and antipsychotics are associated with adverse outcomes, it is important to understand the idiosyncratic factors specific to each country that contribute to variation in use rates. Copyright (c) 2009 John Wiley & Sons, Ltd.

  3. Semiconductor radiation detector

    Science.gov (United States)

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  4. Semiconductor testing method

    International Nuclear Information System (INIS)

    Brown, Stephen.

    1992-01-01

    In a method of avoiding use of nuclear radiation, eg gamma rays, X-rays, electron beams, for testing semiconductor components for resistance to hard radiation, which hard radiation causes data corruption in some memory devices and 'latch-up' in others, similar fault effects can be achieved using a xenon or other 'light' flash gun even though the penetration of light is significantly less than that of gamma rays. The method involves treating a device with gamma radiation, measuring a particular fault current at the onset of a fault event, repeating the test with light to confirm the occurrence of the fault event at the same measured fault current, and using the fault current value as a reference for future tests using light on similar devices. (author)

  5. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  6. Energy distribution in semiconductors

    International Nuclear Information System (INIS)

    Ance, C.

    1979-01-01

    For various semiconductors the dispersive energy Esub(d) defined in the Wemple-Didomenico model is connected with the covalent and ionic energies Esub(h) and C. A continuous curve of ionicity against the ratio of the two energies Esub(A) and Esub(B), connected to Esub(h) and C is reported. Afromowitz's model is applied to the ternary compounds Gasub(1-x)Alsub(x)Sb using optical decomposition. From these results the average energy gap Esub(g) is given by Esub(g) = D 0 M 0 sup((IB))/(epsilon 1 (0)-1) where M 0 sup((IB)) is the interband transition contribution to the optical moment M 0 . (author)

  7. Organic Semiconductor Photovoltaics

    Science.gov (United States)

    Sariciftci, Niyazi Serdar

    2005-03-01

    Recent developments on organic photovoltaic elements are reviewed. Semiconducting conjugated polymers and molecules as well as nanocrystalline inorganic semiconductors are used in composite thin films. The photophysics of such photoactive devices is based on the photoinduced charge transfer from donor type semiconducting molecules onto acceptor type molecules such as Buckminsterfullerene, C60 and/or nanoparticles. Similar to the first steps in natural photosynthesis, this photoinduced electron transfer leads to a number of potentially interesting applications which include sensitization of the photoconductivity and photovoltaic phenomena. Examples of photovoltaic architectures are discussed with their potential in terrestrial solar energy conversion. Several materials are introduced and discussed for their photovoltaic activities. Furthermore, nanomorphology has been investigated with AFM, SEM and TEM. The morphology/property relationship for a given photoactive system is found to be a major effect.

  8. Physical Drivers Vs. Effects of the Wolf-Elk Trophic Cascade on Fluvial Channel Planform, Olympic National Park, Washington

    Science.gov (United States)

    East, A. E.; Jenkins, K. J.; Happe, P. J.; Bountry, J.; Beechie, T. J.; Mastin, M. C.; Sankey, J. B.; Randle, T. J.

    2016-12-01

    Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, U.S.A., to investigate whether physical or trophic-cascade-driven ecological factors—excessive elk impacts after wolves were extirpated a century ago—are the dominant controls on channel planform of these gravel-bed rivers. We find that channel width and braiding show strong relationships with recent flood history; all four rivers have widened significantly in recent decades, consistent with increased flood activity since the 1970s. Channel planform also reflects sediment-supply changes, shown, for example, by the response of the Elwha River to a landslide. We surmise that the Hoh River, which shows a multi-decadal trend toward greater braiding, is adjusting to increased sediment supply associated with rapid glacial retreat. These rivers demonstrate rapid transmission of climatic signals through relatively short sediment-routing systems that lack substantial buffering by sediment storage. We infer no correspondence between channel evolution and elk abundance, suggesting that in this system effects of the wolf-driven trophic cascade are subsidiary to physical controls on channel morphology. Our examinations of stage-discharge history, historical maps, photographs, and descriptions, and empirical geomorphic thresholds do not support a previous conceptual model that these rivers underwent a fundamental geomorphic transition (widening, and a shift from single-thread to braided) resulting from large elk populations in the early 20th century. These findings differ from previous interpretations of Olympic National Park river dynamics, and also contrast with previous findings in Yellowstone National Park, where legacy effects of abundant elk nearly a century ago apparently still affect

  9. Physics with fast molecular-ion beams. Proceedings of workshop held at Argonne National Laboratory, August 20-21, 1979

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1979-01-01

    The Workshop on Physics with Fast Molecular-Ion Beams was held in the Physics Division, Argonne National Laboratory on August 20 and 21, 1979. The meeting brought together representatives from several groups studying the interactions of fast (MeV) molecular-ion beams with matter. By keeping the Workshop program sharply focussed on current work related to the interactions of fast molecular ions, it was made possible for the participants to engage in vigorous and detailed discussions concerning such specialized topics as molecular-ion dissociation and transmission, wake effects, ionic charge states, cluster stopping powers, beam-foil spectroscopy, electron-emissions studies with molecular-ion beams, and molecular-ion structure determinations

  10. Radiological, physical, and chemical characterization of low-level alpha contaminated wastes stored at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Apel, M.L.; Becker, G.K.; Ragan, Z.K.; Frasure, J.; Raivo, B.D.; Gale, L.G.; Pace, D.P.

    1994-03-01

    This document provides radiological, physical, and chemical characterization data for low-level alpha-contaminated radioactive and low-level alpha-contaminated radioactive and hazardous (i.e., mixed) wastes stored at the Idaho National Engineering Laboratory and considered for treatment under the Private Sector Participation Initiative Program. Waste characterization data are provided in the form of INEL Waste Profile Sheets. These documents provide, for each content code, information on waste identification, waste description, waste storage configuration, physical/chemical waste composition, radionuclide and associated alpha activity waste characterization data, and hazardous constituents present in the waste. Information is provided for 97 waste streams which represent an estimated total volume of 25,450 m 3 corresponding to a total mass of approximately 12,000,000 kg. In addition, considerable information concerning alpha, beta, gamma, and neutron source term data specific to Rocky Flats-generated waste forms stored at the INEL are provided to assist in facility design specification

  11. Radiological, physical, and chemical characterization of low-level alpha contaminated wastes stored at the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Apel, M.L.; Becker, G.K.; Ragan, Z.K.; Frasure, J.; Raivo, B.D.; Gale, L.G.; Pace, D.P.

    1994-03-01

    This document provides radiological, physical, and chemical characterization data for low-level alpha-contaminated radioactive and low-level alpha-contaminated radioactive and hazardous (i.e., mixed) wastes stored at the Idaho National Engineering Laboratory and considered for treatment under the Private Sector Participation Initiative Program. Waste characterization data are provided in the form of INEL Waste Profile Sheets. These documents provide, for each content code, information on waste identification, waste description, waste storage configuration, physical/chemical waste composition, radionuclide and associated alpha activity waste characterization data, and hazardous constituents present in the waste. Information is provided for 97 waste streams which represent an estimated total volume of 25,450 m 3 corresponding to a total mass of approximately 12,000,000 kg. In addition, considerable information concerning alpha, beta, gamma, and neutron source term data specific to Rocky Flats-generated waste forms stored at the INEL are provided to assist in facility design specification.

  12. Psychosocial and physical work environment, and risk of pelvic pain in pregnancy. A study within the Danish national birth cohort

    DEFF Research Database (Denmark)

    Juhl, Mette; Andersen, Per Kragh; Olsen, Jørn

    2005-01-01

    OBJECTIVE: The sparse knowledge of the aetiology of pelvic pain in pregnancy makes evidence based prevention a limited option. The aim of this study was to examine the relation between pelvic pain in pregnancy and physical and psychosocial working conditions. METHODS: This study used self reported...... data on working conditions for 1219 cases and 1539 controls, sampled as a nested case-control study within the Danish national birth cohort. Cases and controls were selected on the basis of self reported pelvic pain intensity, pain localisation, and pain impact on daily living activities. Exposure data...... were collected prospectively; early in pregnancy and before the onset of pelvic pain. Main outcome measures were odds ratios for pelvic pain in pregnancy as a function of physical and psychosocial working conditions. RESULTS: Pregnant women with fixed evening work and with rotating shifts (without...

  13. Investigating approaches to diversity in a national survey of physics doctoral degree programs: The graduate admissions landscape

    Science.gov (United States)

    Potvin, Geoff; Chari, Deepa; Hodapp, Theodore

    2017-12-01

    Graduate admissions play a critical gatekeeping role in the physics community not only because they select students who are allowed to begin their graduate studies, but also because they influence how students perceive graduate school, and in some cases whether or not they will even choose to apply. In conjunction with the APS Bridge Program, we conducted a national survey of graduate directors (and related faculty) of physics Ph.D. programs in the United States to explore graduate admissions practices. Our focus was on criteria used in determining admissions, mechanisms through which graduate applicants are handled, and how student representation considerations are incorporated into admissions (if at all). We report here on existing graduate admission practices in physics departments and highlight some critical issues for understanding barriers for diversifying graduate physics, including the use of GRE scores (and the relative importance placed on them). We find that the use of a minimum GRE score for admission, a practice in opposition to recommendations made by the tests designers, is reported to be used in many departments (more than one in three). We also find letters of recommendation to be highly valued in admissions decisions. Our data describe various initiatives at the institutional or individual level to increase gender diversity in admissions. A sizable number of departments also express a latent demand for greater numbers of students from traditionally marginalized racial or ethnic groups, but simultaneously report a lack of such applicants.

  14. A study of the National Physical Laboratory microdosimetry research programme in collaboration with the University of Leeds

    International Nuclear Information System (INIS)

    Menzel, H.G.

    1987-11-01

    A study of the present programme of work carried out by the National Physical Laboratory and the University of Leeds, has been carried out. The study is based on the use of the tissue-equivalent proportional counter in microdosimetic techniques in radiation protection for monoenergetic neutrons or reference radionuclide neutron sources. This report comments on the programme as a whole and provides recommendations for future research work, taking into account the research programmes carried out at other institutions. It also attempts to summarise the present state of knowledge and experience associated with the application of this technique to radiation fields met in routine radiation protection. (author)

  15. PHYSICS

    CERN Multimedia

    Guenther Dissertori

    The time period between the last CMS week and this June was one of intense activity with numerous get-together targeted at addressing specific issues on the road to data-taking. The two series of workshops, namely the “En route to discoveries” series and the “Vertical Integration” meetings continued.   The first meeting of the “En route to discoveries” sequence (end 2007) had covered the measurements of the Standard Model signals as necessary prerequisite to any claim of signals beyond the Standard Model. The second meeting took place during the Feb CMS week and concentrated on the commissioning of the Physics Objects, whereas the third occurred during the April Physics Week – and this time the theme was the strategy for key new physics signatures. Both of these workshops are summarized below. The vertical integration meetings also continued, with two DPG-physics get-togethers on jets and missing ET and on electrons and photons. ...

  16. PHYSICS

    CERN Multimedia

    Chris Hill

    2012-01-01

    The months that have passed since the last CMS Bulletin have been a very busy and exciting time for CMS physics. We have gone from observing the very first 8TeV collisions produced by the LHC to collecting a dataset of the collisions that already exceeds that recorded in all of 2011. All in just a few months! Meanwhile, the analysis of the 2011 dataset and publication of the subsequent results has continued. These results come from all the PAGs in CMS, including searches for the Higgs boson and other new phenomena, that have set the most stringent limits on an ever increasing number of models of physics beyond the Standard Model including dark matter, Supersymmetry, and TeV-scale gravity scenarios, top-quark physics where CMS has overtaken the Tevatron in the precision of some measurements, and bottom-quark physics where CMS made its first discovery of a new particle, the Ξ*0b baryon (candidate event pictured below). Image 2:  A Ξ*0b candidate event At the same time POGs and PAGs...

  17. PHYSICS

    CERN Multimedia

    D. Acosta

    2011-01-01

    Since the last CMS Week, all physics groups have been extremely active on analyses based on the full 2010 dataset, with most aiming for a preliminary measurement in time for the winter conferences. Nearly 50 analyses were approved in a “marathon” of approval meetings during the first two weeks of March, and the total number of approved analyses reached 90. The diversity of topics is very broad, including precision QCD, Top, and electroweak measurements, the first observation of single Top production at the LHC, the first limits on Higgs production at the LHC including the di-tau final state, and comprehensive searches for new physics in a wide range of topologies (so far all with null results unfortunately). Most of the results are based on the full 2010 pp data sample, which corresponds to 36 pb-1 at √s = 7 TeV. This report can only give a few of the highlights of a very rich physics program, which is listed below by physics group...

  18. Cooperative efforts to improve nuclear materials accounting, control and physical protection at the National Science Center, Kharkov Institute of Physics and Technology

    International Nuclear Information System (INIS)

    Zelensky, V.F.; Mikhailov, V.A.

    1996-01-01

    The US Department of Energy (DOE) and the Ukrainian Government are engaged in a program of cooperation to enhance the nonproliferation of nuclear weapons by developing a strong national system of nuclear material protection, control, and accounting (MPC and A). This paper describes the capabilities and work of the Kharkov Institute of Physics and Technology (KIPT) and cooperative efforts to improve MPC and A at this facility. It describes how these cooperative efforts grew out of Ukraine''s decision to become a non-nuclear weapon state and the shortcomings in MPC and A that developed at KIPT after the disintegration of the former Soviet Union. It also envisions expanded future cooperation in other areas of nuclear materials management

  19. Anisotropic magnetoresistance in an antiferromagnetic semiconductor

    Czech Academy of Sciences Publication Activity Database

    Fina, I.; Martí, Xavier; Yi, D.; Liu, J.; Chu, J.-H.; Rayan-Serrao, C.; Suresha, S.; Shick, Alexander; Železný, Jakub; Jungwirth, Tomáš; Fontcuberta, J.; Ramesh, R.

    2014-01-01

    Roč. 5, SEP (2014), "4671-1"-"4671-7" ISSN 2041-1723 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G; GA ČR(CZ) GAP204/10/0330 EU Projects: European Commission(XE) 268066 - 0MSPIN Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : antiferromagnets * semiconductors * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 11.470, year: 2014

  20. Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W.; Johnson, B.M.; Meron, M.

    1986-01-01

    An Atomic Physics Facility (APF) for experiments that will use radiation from a superconducting wiggler on the NSLS X-13 port is described. The scientific justification for the APF is given and the elements of the facility are discussed. It is shown that it will be possible to conduct a uniquely varied set of experiments that can probe most aspects of atomic physics. A major component of the proposal is a heavy-ion storage ring capable of containing ions with energies of about 10 MeV/nucleon. The ring can be filled with heavy ions produced at the BNL MP Tandem Laboratory or from independent ion-source systems. A preliminary cost estimate for the facility is presented.

  1. Institute of Geophysics and Planetary Physics at Lawrence Livermore National Laboratory: 1986 annual report

    International Nuclear Information System (INIS)

    Max, C.E.

    1987-01-01

    The purpose of the Institute of Geophysics and Planetary Physics (IGPP) at LLNL is to enrich the opportunities of University of California campus researchers by making available to them some of the Laboratory's unique facilities and expertise, and to broaden the scientific horizon of LLNL researchers by encouraging collaborative or interdisciplinary work with other UC scientists. The IGPP continues to emphasize three fields of research - geoscience, astrophysics, and high-pressure physics - each administered by a corresponding IGPP Research Center. Each Research Center coordinates the mini-grant work in its field, and also works with the appropriate LLNL programs and departments, which frequently can provide supplementary funding and facilities for IGPP projects. 62 refs., 18 figs., 2 tabs

  2. Determinants of physical activity in America: a first characterization of physical activity profile using the National Health and Nutrition Examination Survey (NHANES).

    Science.gov (United States)

    Kao, Ming-Chih Jeffrey; Jarosz, Renata; Goldin, Michael; Patel, Amy; Smuck, Matthew

    2014-10-01

    To develop and implement methodologies for characterizing accelerometry-derived patterns of physical activity (PA) in the United States in relation to demographics, anthropometrics, behaviors, and comorbidities using the National Health and Nutrition Examination Survey (NHANES) dataset. Retrospective analysis of nationally representative database. Computer-generated modeling in silico. A total of 6329 adults in the United States from the NHANES 2003-2004 database. To discover subtle multivariate signal in the dynamic and noisy accelerometry data, we developed a novel approach, termed discretized multiple adaptive regression and implemented the algorithm in SAS 9.2 (SAS Institute, Cary, NC). Demographic, anthropometric, comorbidity, and behavioral variables. The intensity of PA decreased with both increased age and increased body mass index. Both greater education and greater income correlate with increased activity over short durations and reduced activity intensity over long durations. Numerous predictors demonstrated effects within activity ranges that may be masked by use of the standard activity intensity intervals. These include age, one of the most robust variables, where we discovered decreasing activities inside the moderate activity range. It also includes gender, where women compared with men have increased proportions of active times up to the center of light activity range, and income greater than $45,000, where a complex effect is seen with little correspondence to existing cut-points. The results presented in this study suggest that the method of multiple regression and heat map visualization can generate insights otherwise hidden in large datasets such as NHANES. A review of the provided heat maps reveals the trends discussed previously involving demographic, anthropometric, comorbidity, and behavioral variables. It also demonstrates the power of accelerometry to expose alterations in PA. Ultimately, this study provides a US population-based norm to

  3. Does Dog Walking Predict Physical Activity Participation: Results From a National Survey.

    Science.gov (United States)

    Richards, Elizabeth A

    2016-05-01

    The purpose of this study is to: (1) identify characteristics associated with dog owners who walk their dog, (2) describe the frequency and duration of walking the dog, and (3) determine whether dog owners who walk their dog participate in more physical activity than dog owners who do not walk their dog and non-dog owners. A cross-sectional study design was used. The study setting was nationwide. Adults (n = 4010) participating in the 2005 ConsumerStyles mail-panel survey were the study subjects. Measures used were demographic, physical activity, dog ownership, and dog walking questions from the 2005 ConsumerStyles mail-panel survey. Chi-square tests and analyses of variance were conducted to examine participant characteristics associated with dog walking and to describe the frequency and duration of dog walking. Analysis of covariance was used to determine whether dog owners who walk their dog participate in more physical activity than dog owners who do not walk their dog and non-dog owners. Among dog owners, 42% reported some dog walking in a typical week. Dog owners walked their dog an average 4.3 ± 0.1 times and 128.8 ± 5.6 minutes per week. There were no significant differences in weekly minutes of moderate or vigorous physical activity across the dog-ownership and dog walking groups. Most dog owners did not walk their dog. Dog owners were not more active than non-dog owners, except when considering the activity obtained via dog walking. © The Author(s) 2016.

  4. Modernization of physical protection educational laboratories in the National Research Nuclear University MEPhI

    Science.gov (United States)

    Geraskin, N. I.; Krasnoborodko, A. A.

    2017-01-01

    Non-proliferation of nuclear materials includes, in addition to accounting and control, the Physical Protection (PP) of one. The paper considers the experience by MEPhI in application the practical educational in the area of PP technical systems. The following aspects are discussed in the paper: specific features graduate program in nuclear security area; overview of the practical course curricula in the special laboratory.

  5. The physical environment and major plant communities of the Karoo National Park, South Africa

    OpenAIRE

    Francine Rubin; A.R. Palmer

    1996-01-01

    The major plant communities of the Karoo National Park are described using the methods of the Zurich-Montpellier school of phytosociology, to assist with the formulation of a management strategy for the park. The vegetation physiognomy consists of Montane Karoo grassy shrublands. Karoo grassy dwarf shrublands. Karoo succulent dwarf shrublands and riparian thicket. Steep elevation and precipitation gradients within the study area have a direct impact on gradients in the vegetation. High elevat...

  6. Self-reported physical activity in perceived neighborhood in Czech adults – national study

    Directory of Open Access Journals (Sweden)

    Josef Mitáš

    2013-06-01

    Full Text Available BACKGROUND: International studies associate physical activity (PA to other factors such as the environment, culture, and policy. External influences on lifestyle and PA, such as the effect of the physical and built environment, are discussed. Neighborhood environments seem to be one of the important aspects in prevention of unhealthy lifestyle and physical inactivity research. OBJECTIVE: The main objective is to analyze the relationship between PA and neighborhood environment of the adult population of the Czech Republic. The study tries to define the basic correlates of PA in relation to environmental and other socio-demographic factors. METHODS: Nationwide data collection of adult PA was done regionally in the Czech Republic between the years 2005–2009 using the IPAQ (long and ANEWS questionnaires. RESULTS: The results show that males realize significantly more vigorous PA than females while females realize more moderate PA and walking than males. PA of residents of smaller communities is higher than those living in large cities. The level of weekly PA does not significantly affect the neighborhood walkability [H(3, 8708 = 19.60; p CONCLUSIONS: The results clearly indicate the need to connect multiple sectors that affect the lifestyle of the general population. Possible solution is an interdisciplinary approach to the evaluation of the fundamental environmental factors influencing the level of PA (walkability; SES; participation in organized and voluntary PA; neighborhood safety; type of transportation; size of the community.

  7. Preface: Special issue featuring papers from the International Conference on Nonequilibrium Carrier Dynamics in Semiconductors

    Science.gov (United States)

    Reggiani, L.; Bordone, P.; Brunetti, R.

    2004-02-01

    through the Advisory and Program Committees and peer review, 162 papers were selected for publication by the Institute of Physics Publishing in this special issue of Semiconductor Science and Technology. The financial support that allowed conference organization and helped researchers with budget difficulties to attend came from the following institutions which are gratefully acknowledged: Office of Naval Research (ONR), Defense Advanced Research Project Agency (DARPA), Office of Naval Research International Field Office (ONRIFO), International Union of Pure and Applied Physics (IUPAP), Italian Ministry of Education University and Research (MIUR), National Institute for the Physics of Matter (INFM), University of Modena and Reggio Emilia, Dipartimento di Ingegneria dell’ Innovazione of the Lecce University. Finally, sincere thanks are addressed to the technical staff who provided assistance during the conference: G Angelone, M Benassi, F Grossi, M Leuzzi, A Magnani, S Montanto, L Zagni and D Zanfi. The staff of the University Press Office together with F Goggi and N Minto are acknowledged for their excellent job in printing the conference documents.

  8. Nuclear research at the institute of physics of Azerbaijan national academy of sciences

    International Nuclear Information System (INIS)

    Nagiyev, Sh. M.

    2002-01-01

    In the field of elementary particles and nuclear physics the research of a number of theoretical and experimental problems is being carried out. Theoretical research by axiomatic, symmetric and field theoretical methods in elementary particles and nuclear physics have obtained wider development. Theorists study the problems of electroweak interaction, investigate relativistic composite models in the framework of a finite-difference version of relativistic quantum mechanics and phenomenological aspects of subquark models, develop a description of fundamental interactions in the axiomatic quantum field theory and investigate non-perturbative methods in gauge field theory. Using field theoretical methods, a relativistic covariant Hamiltonian quantum field theory on the light cone (on the light-front planes) for fields with arbitrary spin was developed.The various exactly soluble finite-difference models for some important applications of dynamic quantum systems (linear and three-dimensional harmonic oscillators, hydrogen atoms etc.) were investigated. The wave functions, energy spectra and dynamic symmetry were determined; the coherent states and Wigner distribution functions for the stationary states and the states of thermodynamic equilibrium were constructed.Research related to the possible description of lepton and lepton-hadron interactions within the framework of the weak and electromagnetic interaction theories with spontaneously broken of SU(2)xU(1) gauge symmetry were carried out. The questions of acceptance of different SU(2)xU(1) models were investigated. Several methods for introducing heavy leptons were also considered.It was shown that, the spin interactions in even deformed nuclei generate a new collective branch of monopoly excitations, and are responsible for the formation of observables in experiments on magnetic dipole and Gamov-Teller resonances. The experimental studies are primarily focused on the investigation of the following problems: a) ATLAS

  9. Semiconductor Nanocrystals for Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul

    2005-06-28

    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  10. Giant Geometrically Amplified Piezoresistance in Metal-Semiconductor Hybrid Resistors

    DEFF Research Database (Denmark)

    Hansen, Ole; Reck, Kasper; Thomsen, Erik Vilain

    2008-01-01

    We show that very high geometrically amplified piezoresistance can indeed be obtained in microstructured metal-semiconductor hybrid devices, even significantly higher amplification factors than the factor of approximately 8 demonstrated recently by Rowe and co-workers may be achieved. However, we...... than the sensitivity of conventional piezoresistors fabricated in the same piezoresistive material. ©2008 American Institute of Physics...

  11. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap seimconductors (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas

  12. Janus droplets: liquid marbles coated with dielectric/semiconductor particles.

    Science.gov (United States)

    Bormashenko, Edward; Bormashenko, Yelena; Pogreb, Roman; Gendelman, Oleg

    2011-01-04

    The manufacturing of water droplets wrapped with two different powders, carbon black (semiconductor) and polytetrafluoroethylene (dielectric), is presented. Droplets composed of two hemispheres (Janus droplets) characterized by various physical and chemical properties are reported first. Watermelon-like striped liquid marbles are reported. Janus droplets remained stable on solid and liquid supports and could be activated with an electric field.

  13. Field-effect magnetization reversal in ferromagnetic semiconductor quantum wellls

    Czech Academy of Sciences Publication Activity Database

    Lee, B.; Jungwirth, Tomáš; MacDonald, A. H.

    2002-01-01

    Roč. 65, č. 19 (2002), s. 193311-1-193311-4 ISSN 0163-1829 R&D Projects: GA MŠk OC P5.10 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductor quantum wells * magnetization reversal process Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.327, year: 2002

  14. Magnetization relaxation in (Ga, Mn)As ferromagnetic semiconductors

    Czech Academy of Sciences Publication Activity Database

    Sinova, J.; Jungwirth, Tomáš; Liu, X.; Sasaki, Y.; Furdyna, J. K.; Atkinson, W. A.; MacDonald, A. H.

    2004-01-01

    Roč. 69, č. 8 (2004), 085209/1-085209/6 ISSN 0163-1829 R&D Projects: GA ČR GA202/02/0912 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetization relaxation * ferromagnetic semiconductors Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.075, year: 2004

  15. PHYSICS

    CERN Multimedia

    Darin Acosta

    2010-01-01

    The collisions last year at 900 GeV and 2.36 TeV provided the long anticipated collider data to the CMS physics groups. Quite a lot has been accomplished in a very short time. Although the delivered luminosity was small, CMS was able to publish its first physics paper (with several more in preparation), and commence the commissioning of physics objects for future analyses. Many new performance results have been approved in advance of this CMS Week. One remarkable outcome has been the amazing agreement between out-of-the-box data with simulation at these low energies so early in the commissioning of the experiment. All of this is testament to the hard work and preparation conducted beforehand by many people in CMS. These analyses could not have happened without the dedicated work of the full collaboration on building and commissioning the detector, computing, and software systems combined with the tireless work of many to collect, calibrate and understand the data and our detector. To facilitate the efficien...

  16. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  17. PHYSICS

    CERN Multimedia

    the PAG conveners

    2011-01-01

    The delivered LHC integrated luminosity of more than 1 inverse femtobarn by summer and more than 5 by the end of 2011 has been a gold mine for the physics groups. With 2011 data, we have submitted or published 14 papers, 7 others are in collaboration-wide review, and 75 Physics Analysis Summaries have been approved already. They add to the 73 papers already published based on the 2010 and 2009 datasets. Highlights from each physics analysis group are described below. Heavy ions Many important results have been obtained from the first lead-ion collision run in 2010. The published measurements include the first ever indications of Υ excited state suppression (PRL synopsis), long-range correlation in PbPb, and track multiplicity over a wide η range. Preliminary results include the first ever measurement of isolated photons (showing no modification), J/ψ suppression including the separation of the non-prompt component, further study of jet fragmentation, nuclear modification factor...

  18. PHYSICS

    CERN Multimedia

    L. Demortier

    Physics-wise, the CMS week in December was dominated by discussions of the analyses that will be carried out in the “next six months”, i.e. while waiting for the first LHC collisions.  As presented in December, analysis approvals based on Monte Carlo simulation were re-opened, with the caveat that for this work to be helpful to the goals of CMS, it should be carried out using the new software (CMSSW_2_X) and associated samples.  By the end of the week, the goal for the physics groups was set to be the porting of our physics commissioning methods and plans, as well as the early analyses (based an integrated luminosity in the range 10-100pb-1) into this new software. Since December, the large data samples from CMSSW_2_1 were completed. A big effort by the production group gave a significant number of events over the end-of-year break – but also gave out the first samples with the fast simulation. Meanwhile, as mentioned in December, the arrival of 2_2 meant that ...

  19. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      2012 has started off as a very busy year for the CMS Physics Groups. Planning for the upcoming higher luminosity/higher energy (8 TeV) operation of the LHC and relatively early Rencontres de Moriond are the high-priority activities for the group at the moment. To be ready for the coming 8-TeV data, CMS has made a concerted effort to perform and publish analyses on the 5 fb−1 dataset recorded in 2011. This has resulted in the submission of 16 papers already, including nine on the search for the Higgs boson. In addition, a number of preliminary results on the 2011 dataset have been released to the public. The Exotica and SUSY groups approved several searches for new physics in January, such as searches for W′ and exotic highly ionising particles. These were highlighted at a CERN seminar given on 24th  January. Many more analyses, from all the PAGs, including the newly formed SMP (Standard Model Physics) and FSQ (Forward and Small-x QCD), were approved in February. The ...

  20. PHYSICS

    CERN Document Server

    C. Hill

    2012-01-01

      The period since the last CMS Bulletin has been historic for CMS Physics. The pinnacle of our physics programme was an observation of a new particle – a strong candidate for a Higgs boson – which has captured worldwide interest and made a profound impact on the very field of particle physics. At the time of the discovery announcement on 4 July, 2012, prominent signals were observed in the high-resolution H→γγ and H→ZZ(4l) modes. Corroborating excess was observed in the H→W+W– mode as well. The fermionic channel analyses (H→bb, H→ττ), however, yielded less than the Standard Model (SM) expectation. Collectively, the five channels established the signal with a significance of five standard deviations. With the exception of the diphoton channel, these analyses have all been updated in the last months and several new channels have been added. With improved analyses and more than twice the i...